Parametric Optimization of the Mechanical Characteristics of 3D Printed Kevlar Fibre ‑PHA Composites using Taguchi’s Design of Experiments

Parametric Optimization of the Mechanical Characteristics of 3D Printed Kevlar Fibre ‑PHA Composites using Taguchi’s Design of Experiments | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Parametric Optimization of the Mechanical Characteristics of 3D Printed Kevlar Fibre ‑PHA Composites using Taguchi’s Design of Experiments SANTHOSH NAGARAJA, Praveena Bindiganavile Anand, RAMESHA KODANDAPPA, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8702939/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The paper is a scientific exploration of the optimization of the mechanical characteristics of biodegradable polyhydroxyalkanoates (PHA) reinforced with Kevlar fiber (KF) fabricated through Fused Deposition Modeling (FDM). Composite filaments with different weight fractions of 0 wt.%, 10 wt.% and 20 wt.% Kevlar fiber were processed and printed at different printing speeds (40 mm/s, 60 mm/s, and 80 mm/s), infill densities (60%, 80% and 100%), and build orientations ( 0 o , 45 o and 90 o ). The Taguchi L27 orthogonal array was applied in order to optimize the process parameters in terms of tensile, flexural, and impact properties on the basis of the larger-is-better signal-to-noise (S/N) ratio criterion. The experimental data showed that the ultimate tensile strength was at its highest of about 104 MPa – 105 MPa, flexural strength of up to 97.7 MPa and impact energy of up to 2.25 J at the maximum infill density of 100% and 20 wt. % material content of Kevlar fibers. In case of tensile and flexural strength, the infill density was the most significant factor, and the delta value of the mean response analysis was highest, and Kevlar fiber content was the dominant factor in the optimization of impact strength. There were high synergies between the infill density and Kevlar fiber content as indicated by interaction plots. The similarity between the measured optimal conditions and the experimental ones proves the usefulness of Taguchi optimization in the improvement of the mechanical behavior of FDM-printed PHA–Kevlar fiber composites in terms of lightweight structural applications. Mechanical Engineering Materials Engineering Kevlar Fibre PHA FDM Tensile properties Flexural properties Impact properties Taguchi’s Design of Experiments Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 1. Introduction Additive manufacturing (AM) refers to a layer-by-layer production method that is propelled by computer-aided design (CAD) information and that has significantly developed since its discovery in 1980s [ 1 ]. Fused Deposition Modeling (FDM) has become widely accepted among other AM technologies, as the technology is relatively cost-effective, versatile in material, and well adapted to polymer-based composites [ 2 ]. Within the last few years, fiber reinforcements and streamlined processing techniques have greatly boosted polymer performance in FDM. Interestingly, mechanical strength, interfacial bonding, and structural integrity of continuous Kevlar fiber (KF)-reinforced polymers produced through FDM have significantly improved and thus become appealing in load-bearing uses of low weight in the automotive and aerospace industries [ 3 – 7 ]. Polyhydroxyalkanoates (PHA), which is a biodegradable and sustainable thermoplastic, has come to fill the gap with conventional polymers like ABS that are petroleum-based. Eco-friendly polymer composites are developed in line with green manufacturing, in which natural and bio-derived reinforcements are also studied [ 8 ]. In this regard, Kevlar fiber-reinforced PHA composites are environmentally friendly with high mechanical performance. It has been previously reported that the wear resistance when using KF-polymer composites is greatly enhanced by the addition of nano-fillers, thereby making them useful in dynamically loaded mechanical components [ 9 – 11 ]. Also, the polymer composites made by 3D-printing have been utilized in aerodynamic optimization literature with notable success, which shows the adaptability of the FDM-made polymer structures [ 12 ]. It has also been demonstrated that the inclusion of fiber reinforcements increase flexural strength, resistance to moisture and long term durability in polymer composites even those reinforced with natural fibers such as bamboo and glass fiber waste [ 13 ]. The most frequently extruded polymers in FDM are PHA and ABS because they exhibit a good rheological response and can be easily extruded using filament systems [ 14 ]. Modern technology in FDM has seen the creation of composite filaments, open-source extrusion machines like Recycle Bot, which allows to formulate materials in custom ways and have environmental-friendly production processes [ 15 ]. FDM process is similar, that is, CAD models are converted into STL files and then deposited into layers through material deposition using computer-controlled tool paths [ 16 ]. The incorporation of Kevlar fibers in the PHA mat modulates thermal properties and reduces FDM undesired effects like warping and dimensional errors, and also adds strength and load-carrying capability to the FDM system and fracture strength [ 17 ]. A number of studies have shown significant tensile, flexural, impact, and wear enhancement of KF-reinforced PHA composites, which broadens their application in aerospace, automotive, robotic, and biomedical applications [ 18 ]. Additional optimization of material performance is possible by regulating the fabrication procedures of the filaments, fiber volume ratio as well as extrusion conditions in order to obtain the optimal balance of material performance and cost efficiency [ 19 ]. FDM has a broad range of thermoplastic composites which can be processed and thus have a wider application in industry and not limited to prototyping. In the latest research, the focus on the investigation of new materials and superior printing approaches to increase the durability, functionality, and the service life of FDM-printed parts can be noticed [ 20 – 23 ]. Taguchi and ANOVA are design of experiments (DOE) methods that have been used extensively to optimize printing variables such as layer height, print speed and infill density leading to large gains in the tensile strength of PHA-based composites [ 24 – 27 ]. Such optimized conditions have enabled the PHA composites to be used in high-performance applications in aerospace, automotive and in the medical field. Such experimental work has been done on the enhancement of fiber-matrix interfacial bonding, and optimization of Kevlar fiber roving diameter in KF-PHA composites and significant improvements have been made with tensile and flexural strength results [ 28 , 29 ]. In comparative research on polypropylene/ glass fiber composite produced through FDM and compression molding, it has been established that processing paths have a strong effect on crystallinity and mechanical performance [ 30 ]. The reinforcement of thermoplastic polyurethane (TPI) filaments in short and continuous kinetic force (KF) is also investigated and the findings show considerable tensile strength improvement in comparison to un-reinforced materials [ 31 ]. The mechanical characterization of FDM fabricated KF-PHA composites is normally performed through ASTM standards, such as tensile, flexural, impact, hardness, and wear tests. Detailed testing systems like the four point bending of curved and L-shaped samples have been utilized to test performance under the realistic service environment [ 32 ]. It was demonstrated to be additive, in that with the addition of chopped, continuous Kevlar fibers, thermo-mechanical properties such as tensile strength, flexural modulus and hardness are improved, and that complex geometries may be fabricated in a relatively short period of time [ 33 ]. Recent research of continuous Kevlar fiber reinforced polymer (CKFRP) composites underscores the extreme importance of layer thickness, print orientation and extrusion conditions on the mechanical performance [ 34 – 37 ]. Continuous Kevlar fiber deposition Systems based on dual-nozzle FDM have been reported to report high tensile strength with increasing fiber volume fraction [ 38 ]. Also, research on thin-walled KF PHA samples highlights the importance of printing orientation and material structure to achieve maximum structural efficiency [ 39 ]. Kevlar fiber reinforcement has been useful in stabilizing PHA-based components during printing and service to overcome some problems like warping and deformation of the materials [ 40 ]. Taken altogether, these investigations highlight the possible use of Kevlar fiber-reinforced PHA composites in additive manufacturing. The combination of sustainable material use, fiber reinforcement, and optimum process makes FDM-based KF-PHA composites promising to be used in high-performing, lightweight, and environmental-friendly engineering use. 2. Materials and Methods 2.1 Materials Polyhydroxyalkanoates (PHA) are biodegradable thermoplastic polyester polymers produced by microorganisms through renewable carbon sources as sugar, fats and oils. PHA’s have been receiving growing popularity as alternative materials to petroleum-based polymers in additive manufacturing because of their bio-based source and environmentally compatible properties. Although there are some constraints of thermal stability and post-processing procedures, PHA has extensive application in Fused Deposition Modeling (FDM) due to the relatively low cost, low melting temperature, sufficient mechanical strength, minimal thermal shrinkage during printing, and facilitating intrusiveness. Nevertheless, PHA has a relatively low heat defiance amid widely used FDM polymers, and post-print annealing is required to improve its thermal and dimensional performance. The PHA resin in the current work is sourced from Akruthi Bioresins Impex Pvt. Ltd., Bengaluru, Karnataka, India. Kevlar fibers are high performance synthetic fibers made of long chain aromatic polyamides (aramids), and have an average filament diameter of between 10 m − 12 m. Kevlar fibers are characterized by very high tensile strength, high strength to weight ratio, high stiffness, high chemical resistance, thermal stability and very low coefficient of thermal expansion. Due to these characteristics, Kevlar fibers find widespread application in aerospace elements, civil engineering construction, military protection, and sports gear of high performance. The Kevlar Fibres used in the current work is sourced from Go Green Products Pvt. Ltd., Chennai, India. Kevlar-fiber-reinforced polymers (KFRPs) are developed by embedding Kevlar fibers into polymer matrix to produce lightweight materials that are very rigid and have better load-bearing capacity. Nevertheless, the composites can be brittle because of the concentration of stress at the interface of the fiber and the matrix. Quick heating and cooling in the process of the deposition of fiber-reinforced PHA composites made using the FDM process result in residual thermal stresses, which may cause defects including warping, buckling and dimensional distortion. Post-print annealing is very essential in alleviating these internal stresses, enhancing the interfacial bonding, increasing dimensional stability and the general mechanical performance of the composite structures. The Table 1 gives the properties of PHA and Kevlar Fibre used in the current work. Table 1 Properties of PHA and Kevlar Fibre Property PHA Kevlar Fiber Density (g/cm³) 1.24–1.27 1.76 Tensile strength (MPa) 48–115 ~ 3530 Tensile modulus (GPa) 3.0–4.0 ~ 230 Strain to failure (%) 5–10 ~ 1.5 Melting / Decomposition temperature (°C) 150–160 180–190* PHA-Kevlar fiber composite filaments were made in the current research with 0 wt. %, 10 wt. % and 20 wt. % Kevlar fiber weight fractions. Before the fabrication, the Kevlar fiber and PHA weight ratios were calculated correctly. The sample KF0 was composed of 100% PHA (1000 g). In the KF10 composite, there was 100 g of Kevlar fiber and 900 g of PHA whereas in the KF 20 composite, there were 200 g of Kevlar fiber and 800 g of PHA. Parametric Creo 2020 software was used to design test samples and was exported in the form of stereo lithography files (.STL). The STLs were sliced with the cura slicing software in which the printing parameters including the layer height (0.2 mm), nozzle temperature, and bed temperature were adjusted. The fabrication of the specimens was conducted with the help of a 3D Print kart FDM printer that has a more stable mechanism and better surface finish, as well as a convenient interface in comparison to printers of previous generations. Transfer of the sliced files was made to the printer through the USB flash drive and the printing was done by feeding the filament of composite through the extruder, which was then melted and deposited through the nozzle in a layer-by-layer fashion. The build platform was cleared after removal, the support structures, and the printed specimens were then detached and the samples were made ready to undergo mechanical characterization. 2.2 Methodology The manufacturing and testing of PHA-Kevlar fiber reinforced polymer composites was done through fused deposition modeling (FDM) technique. The choice of printing parameters was informed by material choice, pre-experiments and literature sources in order to achieve consistent extrusion and sample fabrication without defects. All specimens were printed with an industrial-level 3D Printzkart FDM printer under conditions of controlled ambient environment. The printing was done through the preparation of the CAD models in Parametric Creo 2020 that were put into stereolithography (.STL) files that were then entered into Cura slicing software. A USB interface was used to feed the sliced files to the printer, and the composite filament into the extruder, where it was heated and deposited in layers by a constant layer thickness of 0.2 mm by a heated nozzle with a constant print speed, infill density and raster orientation. Mechanical characterization of the specimens was then conducted to determine the effect of Kevlar fiber reinforcement and printing parameter on the composites performance following fabrication. The tensile and flexural tests together with the impact and wear tests were performed based on the ASTM standards to make the results reliable and comparable. Tensile test was conducted according to ASTM D638 [ 41 ] on a universal testing machine and specimens that had a total length of 165 mm and a maximum width of 19 mm with a width of 3.2 mm were tested to fracture (Fig. 1 ). The test configuration was used to provide accurate load application, crosshead speed, and measure load-extension behavior, and errors caused by misaligning specimens or slippage at the grips were kept to a minimum. The flexural properties were tested on rectangular specimens that were made as per the ASTM D7264 standards [ 42 ]. The sample size (125 mm x 12.7 mm x 3.2 mm) was 3D printed using the CAD model as shown in Fig. 2 , and then placed into the testing setup of three-point bending to find the flexural strength. The test results were justified by all the tested specimens fracturing within the acceptable strain limit of 5% which is given by ASTM D790 [ 43 ]. Impact resistance was found using notched specimens manufactured as per the ASTM D256 requirements [ 44 ]. The specimens were 64 mm x 12.7 mm x 3.2 mm in size and had a V-notch of 45 o angle cut below the top edge at the center as shown in the Fig. 3 . Impact tests were done in order to measure the energy absorbed by the material in sudden loading conditions which helped to understand the toughness of the PHA-Kevlar fiber composites. The Taguchi’s design of experiments (DoE) approach was utilized in order to maximize the mechanical performance of the composites with the help of MINITAB 17 software [ 63 ]. To reduce the amount of experimental trials, an L27 orthogonal array [ 45 – 47 ] was chosen to study the effect of four FDM process parameters at three levels, which provides statistical significant results. The factors and the parametric levels used in the DoE is given in Table 2 . Table 2 Factors and Parametric Level used in Taguchi’s DoE in the present work Factor Parameter Level 1 Level 2 Level 3 A Printing speed (mm/s) 40 60 80 B Infill density (%) 80 90 100 C Build orientation (°) 0 45 90 D Kevlar Fibre (Wt. %) 0 10 20 The analysis of signal-to-noise (S/N) ratio was done based on the larger-the-better criterion of mechanical properties including tensile strength, flexural strength, and impact energy. An increase in the S/N ratios showed more strength of the process and decreased the sensitivity to the noise factors [ 48 ]. The most influential parameters were revealed with the help of response tables and main effect plots in order to find the best combinations of these parameters. Furthermore, a detailed DoE analysis was conducted to analyze the generated relationship between input factors and the output reactions in the FDM process. Data collection, statistical analysis and interpretation of results were done in a systematic manner to determine the stability and capability of processes [ 49 ]. The signal to noise ratio acted as a guide that there was preeminence of factors that are controllable over those that are noise factors and that there is a need to overpower the design and reduce the variability [ 50 ]. The tables of responses that were produced by the DoE have given quantitative ranking of the process parameters, which is important in determining how the process parameters influence the mechanical performance in addition to guaranteeing that the optimized conditions produced stable, repeatable, and reliable composite fabrication. 3. Results and Discussion 3.1 Tensile Test Results The Table 3 summarizes the tensile test results and depicts as to how printing speed, build orientation, infill density and Kevlar fiber (KF) affects the mechanical response of PHA-based composites fabricated through FDM. 27 specimens were tested, which represents an L27 Taguchi orthogonal array (OA), and it was possible to systematically assess the chosen process parameters and the material compositions. Table 3 Tensile Test Results as per Taguchi’s L27 Orthogonal Array Sample no Speed (mm/s) Orientation (°) Infill Density (%) KF (Wt.%) Ultimate Load (kN) Ultimate Tensile Strength (MPa) Elongation (%) 1 40 0 60 0 3.46 84.7 3.17 2 40 0 80 10 3.02 74.1 1.27 3 40 0 100 20 4.21 103.2 0.95 4 40 45 60 10 2.16 52.9 1.89 5 40 45 80 20 2.70 66.2 1.27 6 40 45 100 0 3.46 84.7 0.64 7 40 90 60 20 3.67 90.0 1.89 8 40 90 80 0 3.56 87.3 3.17 9 40 90 100 10 3.67 90.0 1.27 10 60 0 60 0 4.00 97.9 3.80 11 60 0 80 10 2.38 58.2 0.95 12 60 0 100 20 3.78 92.6 1.27 13 60 45 60 10 3.35 82.0 0.95 14 60 45 80 20 3.46 84.7 0.95 15 60 45 100 0 3.46 84.7 1.27 16 60 90 60 20 2.48 60.9 0.95 17 60 90 80 0 3.46 84.7 3.17 18 60 90 100 10 3.56 87.3 1.27 19 80 0 60 0 3.89 95.3 3.17 20 80 0 80 10 3.56 87.3 1.27 21 80 0 100 20 4.21 104.6 1.27 22 80 45 60 10 3.13 76.7 0.95 23 80 45 80 20 2.70 66.2 1.27 24 80 45 100 0 3.24 79.4 0.95 25 80 90 60 20 3.78 92.6 1.27 26 80 90 80 0 3.35 82.0 3.17 27 80 90 100 10 3.78 92.6 1.89 In every specimen, final tensile strength (UTS) and final load were highly influenced by the infill density and the content of Kevlar fibers. The specimens that were printed with 100% infill usually had a better load bearing capacity and tensile strength than their 60% to 80% counterparts, which showed better load transfer internally and a lower porosity. Sample coils with 20 wt.% Kevlar fiber and infill density of 100% showed the highest tensile strengths with maximum UTS values of between 103 MPa and 105 MPa (Samples 3 and 21). This verifies the positive action of Kevlar fiber reinforcement to the strength of PHA composites in circumstances where continuity of the material is achieved in adequate numbers. The speed of printing also had an impact on tensile behavior, but the effect was not so significant as infill density and KF content. Moderate printing speeds (60–80 mm/s) had the propensity to create greater ultimate loads and tensile strengths in comparison with those lower in speed, indicating enhanced interlayer bonding and stability of filament deposition at these settings. With neat PHA (0 wt.% KF), tensile strength values generally fell within 80 MPa to 98 MPa, with the highest ratio of elongation (up to about 3.8%) at the lower infill densities and advantageous to the build positions, which was indicative of more ductile behavior. Build orientation also gained a great influence on tensile performance because the FDM process is inherently anisotropic. The tensile strength and ultimate load of specimens printed at 0 o orientation tended to be stronger than those at 45 o and 90 o orientation of the printing since the load was pointed to the direction of filament deposition. Conversely, the tensile strength of samples printed at 45 o orientation was relatively lower, which is explainable by the fact that, the interlayers shear would be higher and the bonding along the load path will be less favorable. Break elongation declined significantly with more content of Kevlar fibers. Neat PHA samples had more elongation values, with values up to 3.8 wt. %, but composites with 10 wt. % and 20 wt. % KF had lower values of elongation. This decrease in ductility can be linked to the rigidity and brittle character of Kevlar fibers that prevents chain mobility in polymer and causes fracture sooner in response to tensile stress [ 50 – 52 ]. 3.2 Flexural Test Results The flexural test data of the PHA and PHA-Kevlar fiber (KF) composite specimens manufactured via FDM process under different printing velocities, print build orientations, infill densities, and Kevlar fiber content is presented in the Table 4 . The experimental matrix is composed of 27 samples according to L27 Taguchi orthogonal array, to allow a systematic study of the joint action of processing and material parameters on peak load and flexural strength [ 53 ]. Table 4 Flexural Test Results as per Taguchi’s L27 Orthogonal Array Sample no Speed (mm/s) Orientation (°) Infill Density (%) KF (Wt.%) Peak Load (kN) Flexural Strength (MPa) 1 40 0 60 0 256.16 76.44 2 40 0 80 10 195.94 58.42 3 40 0 100 20 249.15 74.33 4 40 45 60 10 271.67 81.04 5 40 45 80 20 237.08 70.73 6 40 45 100 0 250.35 74.70 7 40 90 60 20 267.86 79.68 8 40 90 80 0 231.64 69.11 9 40 90 100 10 256.67 75.95 10 60 0 60 0 283.86 84.65 11 60 0 80 10 247.28 73.71 12 60 0 100 20 317.93 94.84 13 60 45 60 10 277.04 82.66 14 60 45 80 20 237.84 70.98 15 60 45 100 0 327.41 97.70 16 60 90 60 20 276.32 82.41 17 60 90 80 0 254.78 75.95 18 60 90 100 10 256.65 79.68 19 80 0 60 0 275.80 82.29 20 80 0 80 10 246.78 73.59 21 80 0 100 20 278.20 83.03 22 80 45 60 10 291.02 86.76 23 80 45 80 20 284.63 84.90 24 80 45 100 0 256.91 76.69 25 80 90 60 20 290.52 86.64 26 80 90 80 0 256.81 76.57 27 80 90 100 10 271.33 80.92 The findings reveal that printing speed and infill density have a strong effect on both the peak load and flexural strength. Generally, the flexural performance of specimens with higher infill densities was better because with high material continuity and low internal porosity there was a higher resistance to bending loads. Sample 15, which was printed at a speed of 60 mm/s, 45 o orientation, and 100% infilled with neat PHA gave the highest flexural strength of 97.70 MPa. There were also high flexural strengths that were found when the sample was printed at 60 mm/s and with 100% infill density, like Sample 12, with the flexural strength of 94.84 MPa, a condition indicating the best processing conditions. The speed of printing was an important factor in flexural behavior pattern. Samples printed at moderate rate of 60 mm/s had a steady high peak loads and flexural strengths than those that were printed at rate of 40 mm/s and those that were printed at rate of 80 mm/s. The implied trend is that a medium rate of printing fosters enhanced interlayer fusion along with uniform filament deposition, which are vital in enhancing the bending resistance. The orientation of the building also influenced flexural characteristics because the FDM-printed pieces were anisotropic. Experiments run at low temperatures (0 o C ) and orientations (45 o C) tended to have a better flexural strength than those run at high temperatures (90 o C) because the alignment of the filament was more favorable relative to stresses applied during bending. Nevertheless, orientation-related weaknesses were partially alleviated with the incorporation of the Kevlar fiber through which a few 90 o oriented composite specimens were able to record competitive values of flexural strength. Flexural performance was found to be dependent on the content of Kevlar fibres throughout the entire dataset [ 54 ]. Peak loads under comparable processing conditions were frequently also higher in composites with 10 wt. % and 20 wt. % KF than in neat PHA specimens, which is due to the reinforcing nature of Kevlar fibers. However, the increase in flexural strength did not directly relate to the fibre content implying that other factors like fiber distribution, interfacial bonding and print parameters are also important factors [ 55 – 57 ]. 3.3 Impact Test Results The Table 5 summarizes the impact test findings of FDM-printed PHA and PHA-Kevlar fiber (KF) composite samples fabricated at varying printing speed, build orientation, infill densities and Kevlar fiber contents according to L27 Taguchi experimental set up [ 58 ]. Impact energy is the capacity of the material to take energy when suddenly loading and it is a measure of toughness expressed in joules. Table 5 Impact Test Results as per Taguchi’s L27 Orthogonal Array Sample Speed (mm/s) Orientation (°) Infill Density (%) KF (Wt.%) Impact Energy (J) 1 40 0 60 0 0.35 2 40 0 80 10 0.85 3 40 0 100 20 2.00 4 40 45 60 10 0.65 5 40 45 80 20 1.30 6 40 45 100 0 1.05 7 40 90 60 20 1.10 8 40 90 80 0 0.90 9 40 90 100 10 1.25 10 60 0 60 0 0.55 11 60 0 80 10 1.05 12 60 0 100 20 2.10 13 60 45 60 10 0.95 14 60 45 80 20 1.45 15 60 45 100 0 1.20 16 60 90 60 20 1.35 17 60 90 80 0 1.05 18 60 90 100 10 1.40 19 80 0 60 0 0.75 20 80 0 80 10 1.15 21 80 0 100 20 2.25 22 80 45 60 10 1.10 23 80 45 80 20 1.55 24 80 45 100 0 1.35 25 80 90 60 20 1.50 26 80 90 80 0 1.15 27 80 90 100 10 1.65 There is an obvious trend which seems to remain the same in regard to infill density. The samples that have been printed with 100% infill contain the most considerable impact energy in all the printing speed and orientations with about 80% and 60% infill. This is because of decreased internal porosity and better load distribution in harder structures, which leads to increased resistance to crack initiation and propagation during impact loading. The impact performance of Kevlar fiber reinforcement is very strong. The composites with 20 wt.% KF would always have higher impact energy than that of 10 wt.% KF composites and neat PHA. The enhanced toughness is linked to energy-absorbing processes including fiber pull-out, crack bridging, and interfacial debonding, which is more efficient in dissipating the impact energy as compared to the polymer matrix itself. Although the neat PHA samples have relatively higher ductility, they have low impact energy since they lack the fiber-based toughening mechanisms. The influencing effect of the printing speed on the impact energy is moderate. Sample specimens made at 60 mm /s and at 80mm/s tend to show a better impact resistance than those printed at 40mm/s, indicating better interlayer fusion and enhanced bonding at moderate to high deposition rates. Nevertheless, the influence of printing speed is not that dominant as infill density and Kevlar fiber content. Impact behavior is also influenced by build orientation, but not so much. Printed samples at a 45 o orientation and 90 o orientation are more likely to absorb the impact energy as compared to the 0 o orientation especially in Kevlar-reinforced composites. This is explained by the presence of modified crack paths and the increase of energy dissipation due to fiber-matrix interactions in the case of off-axis loading. 3.4 Parametric Optimization of Test Results 3.4.1 Ultimate Tensile Strength The parametric optimization using Taguchi’s analysis indicated that the infill density has the greatest impact on the final tensile strength (UTS) of FDM-printed PHA-Kevlar fiber composites, with build orientation second and Kevlar fiber content third, and printing speed had the least effect [ 59 – 60 ]. The larger-is-better criterion of signal-to-noise (S/N) ratio analysis showed that the best choice of parameters to maximize UTS is high printing speed (Level 3), 100% infill density (Level 3), 0, build orientation (Level 1), and increased Kevlar fiber reinforcement. This mix will guarantee a better filament continuity, efficient load alignment, and an increase in the fiber-matrix stress transfer. The Table 6 gives the Response table for mean values, while the Table 7 gives the response table for S/N ratio. The S/N ratio results were further supported by the corresponding response table of means whereby there was a significant increment in the average tensile strength at increased infill densities and both positive and negative build orientations. Printed samples with 100% infill experienced the greatest mean UTS and this validates the importance of dense internal structures in reducing voids and enhancing load-bearing capacity. Incorporation of Kevlar fiber made tensile strength much higher than that of neat PHA, though the improvement was at the expense of ductility; this is in line with the stiff and brittle properties of aramid fibers. Table 6 Response table for mean values for UTS Level Printing Speed (mm/s) Infill Density (%) Build Orientation (°) Kevlar Fiber (wt. %) 1 81.46 81.44 88.66 86.74 2 81.45 76.74 75.28 77.90 3 86.30 91.01 85.27 84.56 Delta 4.85 14.27 13.38 8.84 Rank 4 1 2 3 Table 7 Response table for S/N ratio for UTS Level Printing Speed (mm/s) Infill Density (%) Build Orientation (°) Kevlar Fiber (wt. %) 1 38.07 38.06 38.83 38.75 2 38.10 37.62 37.44 37.69 3 38.65 39.15 38.56 38.39 Delta 0.58 1.53 1.39 1.06 Rank 4 1 2 3 The SN ratio and interaction plot analysis in Fig. 4 and Fig. 5 show that there is a significant interaction between infill density and build orientation and also between infill density and Kevlar fiber content. Kevlar fiber strengthening effect was the greatest at the increase in infill densities, which suggests that sufficient material continuity is a critical requirement in efficient stress transfer between the fiber and the polymer matrix. Relationships with printing speed were rather weak indicating that the effect on UTS is quite independent in the parameter range of study. 3.4.2 Flexural Strength The response matrix in Table 8 and Table 9 show how the printing speed, infill density, orientation of the build, and Kevlar fiber content affect the desired mechanical response using the signal-to-noise (S/N) ratio analysis and mean response values depending on the Taguchi larger-is-better criterion. These tables are employed to see an approximate importance of every process parameter and to select the best levels of factors that will facilitate an improved performance. S/N ratio response table shows that the density of the infill has the most significant effect on the response as the delta of 1.14 is the highest and it’s Rank of 1. This shows how the internal material continuity and low porosity are very vital when it comes to enhancing the stability and uniformity of the mechanical performance. The speed of printing is second with a delta value of 1.01, with a relatively large but relatively less significant impact on the response. The content of Kevlar fiber is the third one, and it is rated as a moderate delta of 0.44, which means that fiber reinforcement does not dominate but has a contributing role in the studied range of infill density and printing speed. Build orientation presents the least impact with the minimal delta of 0.33 and thus it occupies the fourth position. The trend in the S/N ratio analysis is also further supported by the response table of mean values. The infill density once again appears to be the most significant parameter with the largest delta value of 9.85 and the Rank 1. This proves that the more the infill, the higher the average mechanical response. The second rank is of printing speed with 9.13 delta value which means that it had an enormous impact on the mean response. The third one is the content of Kevlar fiber whose delta of 3.87 indicates its contribution to the strength of the composite and the least influential factor is the build orientation, which has the lowest delta value of 2.76. Table 8 Response table for S/N ratio for Flexural Strength Level Printing Speed (mm/s) Infill Density (%) Build Orientation (°) Kevlar Fiber (wt. %) 1 37.28 38.32 37.77 37.95 2 38.29 37.19 38.09 37.68 3 38.18 38.23 37.89 38.12 Delta 1.01 1.14 0.33 0.44 Rank 2 1 4 3 Table 9 Response table for mean values for Flexural Strength Level Printing Speed (mm/s) Infill Density (%) Build Orientation (°) Kevlar Fiber (wt. %) 1 73.38 82.51 77.92 79.34 2 82.51 72.66 80.68 76.97 3 81.27 81.98 78.55 80.84 Delta 9.13 9.85 2.76 3.87 Rank 2 1 4 3 The Taguchi method was applied to maximize flexural strength of PHA-Kevlar fiber composites fabricated using the FDM technique, given that the larger-is-better signal-to-noise (S/N) ratio [ 61 ]. The dominating impacts that the infill density has on the flexural performance are shown in the main effects plot in Fig. 6 , where the higher the S/N ratios at the higher levels of infill because of the better continuity of the material and lower internal porosity. The rate of printing also has an apparent influence, and a median rate of printing the material provides a higher flexural strength due to better bonding between layers. The orientation of the building has a relative smaller effect, but specimens that are patterned in the middle have better bending resistance. The content of Kevlar fibers has a positive effect on flexural strength, and the increased reinforcement level increases the stiffness and carrying capacity. The interaction plots in Fig. 7 indicate that the density of the infill is also much in interaction with printing speed and Kevlar fiber content. The positive reinforcement of Kevlar fibre increases with the increase in infill density, which means the reinforcement of the stress is more effective in the denser structure. Likewise, a more optimized printing speed gives improved flexural performance with an increase in infill density. In general, the Taguchi analysis confirms that infill density is the most important factor determining flexural strength, then is printing speed and content of Kevlar fibers, and secondary is the build orientation. The agreement of the main effects and interaction patterns illustrates that Taguchi methodology is effective in optimization of flexural performance in PHA Kevlar fiber composites manufactured through FDM. 3.4.3 Impact Strength The S/N ratio response matrix in Table 10 shows that the element that has the most impact is the content of Kevlar fiber content since it has the maximum delta of 5.2501 and is ranked at the top. This shows how the reinforcement of fiber prevails in enhancing the strength and steady-ness of the reaction. Infill density comes second with a delta value of 5.1718, which shows that it has a strong contribution, because it has high material continuity and low internal porosity. The third most influential element is printing speed which has a moderate impact on the response with build orientation having the least impact as indicated by the smallest delta value of 1.5516 and the fourth ranking. Table 10 Response table for S/N ratios for Impact Strength Level Printing Speed (mm/s) Infill Density (%) Build Orientation (°) Kevlar Fiber (wt. %) 1 −0.4109 −1.4681 0.3250 −1.2748 2 1.3327 1.1402 1.1742 0.6752 3 2.4539 3.7037 1.8766 3.9753 Delta 2.8648 5.1718 1.5516 5.2501 Rank 3 2 4 1 The trends in the analysis of S/N ratio are supported by the response of means in Table 11 . Once again, the content of Kevlar fiber becomes the most important, with the greatest delta of 0.6944, which validates the fact that the marked increase in the reinforcement with fiber contributes to the significant change in the mean response. The next in rank with a delta of 0.6611 is the infill density which supports its significance in increasing the mechanical performance. Printing speed has a moderate impact with a delta of 0.3333 and the meaning of building orientation has little impact on the mean response as shown by the least delta of 0.0833. Table 11 Response table for means for Impact Strength Level Printing Speed (mm/s) Infill Density (%) Build Orientation (°) Kevlar Fiber (wt. %) 1 −0.4109 −1.4681 0.3250 −1.2748 2 1.3327 1.1402 1.1742 0.6752 3 2.4539 3.7037 1.8766 3.9753 Delta 2.8648 5.1718 1.5516 5.2501 Rank 3 2 4 1 Figure 8 shows the plot of the key effects of signal-to-noise (S/N) ratios of impact strength using the larger-is-better criterion. As the plot depicts, infill density and Kevlar fiber content affect the impact performance the most as shown by the steep rise in S/N ratio with the rise in level of the two parameters. Optimal S/N ratios are realized at 100% infill density and 20 wt. % Kevlar fiber, and this implies that toughness is enhanced by decreased internal voids and that fiber-based energy dissipation mechanisms are effective. Speed of printing also gives a positive impact and it is higher the speed of printing, the higher the S/N ratios, indicating a better bond between layers. Build orientation has a relatively lower impact, but higher orientations have a marginal increase in impact performance. The Fig. 9 shows the interaction graph of the S/N ratios of impact strength, showing the interaction of the printing speed, infill density, build orientation, and the amount of Kevlar fibers. It has been found that the infill density and the content of Kevlar fibers have strong interactions in such a way that the positive influence of fiber reinforcement is more pronounced in denser structures. The relations between printing speed and infill density also display that the higher printing speed, the more efficient is its combination with high infill density in terms of improving impact strength. The interaction patterns also reveal that Kevlar fiber reinforcement nullifies the effects of build orientation resulting in the enhancement of impact resistance in varying directions of printing. On the whole, the interaction plot proves that the strength of impact is controlled by the synergistic effects of the material composition and process parameters, but the infill density and content of Kevlar fibers are the most important [ 62 – 63 ]. 4. Conclusions The Taguchi-based parametric optimization has a great impact on the mechanical performance of FDM-fabricated PHA composites. The tensile strength, flexural strength and impact resistance increased significantly as a result of introducing optimum Kevlar fiber and choosing appropriate infill density thus supporting the appropriateness of aramid fiber reinforcement to biodegradable polymer systems. The results of tensile tests indicated that the ultimate tensile strength rose to more than 100 MPa when there was 20 wt. % Kevlar fiber in the composite at 100% infill density and optimal orientation of the build. Flexural strength behaved in the same way with a maximum of 97.7 MPa and this means that there is a better ability to resist bending forces because of greater fiber-matrix stress transfer. Kevlar fiber addition to the impact performance showed that the maximum absorbed energy went up to levels that were less than 0.5 J in the low-infill neat PHA specimen, and up to around 2.25 J in the highly reinforced fully dense composites. Taguchi signal to noise analysis and mean response analysis continuously determined infill density to be the largest factor affecting tensile and flexural strength (Rank 1) then Kevlar fiber content then printing speed and then build orientation had the lowest influence. In the case of impact strength, the most important parameter was Kevlar fiber content, and the delta value of both the tables of S/N ratios and mean response was maximum. The combination of parameters, which was predicted by the Taguchi method as the best, higher infill density, more Kevlar fibers and moderate-high speed of printing, confirmed the adequacy of the optimization technique. Generally, the experiment confirms that systematic Taguchi optimization, with Kevlar fibers reinforcement is a relevant approach to customize the mechanical characteristics of biodegradable PHA composites manufactured through FDM. The optimized PHA-kevlar fiber composites can be used in lightweight, load-bearing, and impact-resistant engineering applications with mechanical properties, which are comparable to synthetic polymers. Declarations Ethics Statement: "The research aims to contribute to academic knowledge while upholding the highest ethical standards in data collection and analysis." Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Data availability statement "Data supporting the research work is embedded within the manuscript, and any additional data related to work can be obtained upon requisition to the corresponding author." author’s contribution statement Conceptualization, S.N. and P.B.A.; methodology, S.N., P.B.A., and A.F.; formal analysis, S.N. and R.K.; investigation, S.N. and R.K.; data curation, R.K.; writing—original draft preparation, S.N.; writing—review and editing, P.B.A., R.K., and A.F.; visualization, A.F.; supervision, P.B.A.; project administration, P.B.A. All authors have read and agreed to the author’s contribution statement and herewith abide by the publication ethics and guidelines. Author Initials: S.N.: Santhosh Nagaraja; P.B.A.: Praveena Bindiganavile Anand; R.K.: Ramesha Kodandappa; A.F.: Adisu Frinjo. References Norizzati Z, Dhar S, Siti M, Hajar Sheikh Md, Zaleha F, Mustafa KamarulAriffin, Zakaria SS (2019) Effect of water Prashar, G., Vasudev, H. and Bhuddhi, D. (2023). 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(eds) Advances in Structures, Systems and Materials. Lecture Notes on Multidisciplinary Industrial Engineering. Springer, Singapore. https://doi.org/10.1007/978-981-15-3254-2_27 Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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NAGARAJA","email":"data:image/png;base64,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","orcid":"https://orcid.org/0000-0002-3683-9356","institution":"DAYANANDA SAGAR ACADEMY OF TECHNOLOGY AND MANAGEMENT, KANAKAPURA ROAD, BENGALURU 560082","correspondingAuthor":true,"prefix":"","firstName":"SANTHOSH","middleName":"","lastName":"NAGARAJA","suffix":""},{"id":580691540,"identity":"abe79d30-f54b-4c88-817c-92634327892c","order_by":1,"name":"Praveena Bindiganavile Anand","email":"","orcid":"https://orcid.org/0000-0001-7250-4599","institution":"NITTE MEENAKSI INSTITUTE OF TECHNOLOGY","correspondingAuthor":false,"prefix":"","firstName":"Praveena","middleName":"Bindiganavile","lastName":"Anand","suffix":""},{"id":580691541,"identity":"5b6d15ad-2af5-43b8-981f-07e74ddcd997","order_by":2,"name":"RAMESHA KODANDAPPA","email":"","orcid":"https://orcid.org/0000-0002-3725-5563","institution":"CHRIST (Deemed to be University)","correspondingAuthor":false,"prefix":"","firstName":"RAMESHA","middleName":"","lastName":"KODANDAPPA","suffix":""},{"id":580691542,"identity":"c9ee1c92-9a78-44c7-b2c6-8bf7a473f92b","order_by":3,"name":"Adisu Frinjo","email":"","orcid":"","institution":"Dilla University","correspondingAuthor":false,"prefix":"","firstName":"Adisu","middleName":"","lastName":"Frinjo","suffix":""}],"badges":[],"createdAt":"2026-01-26 17:59:05","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-8702939/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8702939/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101364887,"identity":"ccd8c2eb-af82-42bd-bc99-01363414d7a5","added_by":"auto","created_at":"2026-01-29 00:53:01","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":55703,"visible":true,"origin":"","legend":"\u003cp\u003eIsometric CAD model of the 3D printed tensile specimen (ASTM D638)\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/43307fe6a84e7259f8807675.png"},{"id":101398433,"identity":"d41d1628-60c3-49e1-9ca2-31a6de88eeb2","added_by":"auto","created_at":"2026-01-29 09:41:25","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":36982,"visible":true,"origin":"","legend":"\u003cp\u003eIsometric CAD model of the 3D printed flexural specimen (ASTM D7264)\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/f73570443258cfc2a483a28b.png"},{"id":101398447,"identity":"f20464f6-202f-487f-a289-00f6d62a2a59","added_by":"auto","created_at":"2026-01-29 09:41:34","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":40142,"visible":true,"origin":"","legend":"\u003cp\u003eIsometric CAD model of the 3D printed impact test specimen (ASTM D256)\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/24a749ad3d87959603dbc5c6.png"},{"id":101364885,"identity":"1a5ffdd1-68ec-48ff-948f-7c3e46db3930","added_by":"auto","created_at":"2026-01-29 00:53:01","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":19777,"visible":true,"origin":"","legend":"\u003cp\u003eMain Effects Plot for SN Ratios from Parametric Analysis of UTS\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/e3ea60c01ae5cc9da7aa2400.png"},{"id":101364882,"identity":"17a82be7-058a-4ca3-8a60-b6d8e10801b6","added_by":"auto","created_at":"2026-01-29 00:53:01","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":34812,"visible":true,"origin":"","legend":"\u003cp\u003eInteraction Plot for SN Ratios from Parametric Analysis of UTS\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/898f8d2497ade6171cbc211f.png"},{"id":101364881,"identity":"cdaf9960-036d-43f6-b58c-4b8a041239e5","added_by":"auto","created_at":"2026-01-29 00:53:01","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":26746,"visible":true,"origin":"","legend":"\u003cp\u003eMain Effects Plot for SN Ratios from Parametric Analysis of Flexural Strength\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/84dc4bd73f9937aedee68da8.png"},{"id":101364884,"identity":"05cc552d-4778-4caf-bc7f-eb712a8a98c1","added_by":"auto","created_at":"2026-01-29 00:53:01","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":40754,"visible":true,"origin":"","legend":"\u003cp\u003eInteraction Plot for SN Ratios from Parametric Analysis of Flexural Strength\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/a2ca14b7e4752d27b114b2a8.png"},{"id":101364888,"identity":"a9e802a7-4f6b-4f97-826d-b6b43f49e5f4","added_by":"auto","created_at":"2026-01-29 00:53:01","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":24693,"visible":true,"origin":"","legend":"\u003cp\u003eMain Effects Plot for SN Ratios from Parametric Analysis of Impact Strength\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/a302768d1b64450a5aeeb74c.png"},{"id":101398186,"identity":"bb582a92-7ec8-49a9-9d64-dfb310c9bc72","added_by":"auto","created_at":"2026-01-29 09:39:59","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":39262,"visible":true,"origin":"","legend":"\u003cp\u003eInteraction Plot for SN Ratios from Parametric Analysis of Impact Strength\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/00c3a494c6a6a42f55d4e61d.png"},{"id":101399133,"identity":"edd77ca1-d844-46a6-93fd-f752c1bdf23b","added_by":"auto","created_at":"2026-01-29 09:52:07","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1905375,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8702939/v1/5baccde4-77c2-4319-b39e-c14782019e30.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eParametric Optimization of the Mechanical Characteristics of 3D Printed Kevlar Fibre ‑PHA Composites using Taguchi’s Design of Experiments\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eAdditive manufacturing (AM) refers to a layer-by-layer production method that is propelled by computer-aided design (CAD) information and that has significantly developed since its discovery in 1980s [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Fused Deposition Modeling (FDM) has become widely accepted among other AM technologies, as the technology is relatively cost-effective, versatile in material, and well adapted to polymer-based composites [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Within the last few years, fiber reinforcements and streamlined processing techniques have greatly boosted polymer performance in FDM. Interestingly, mechanical strength, interfacial bonding, and structural integrity of continuous Kevlar fiber (KF)-reinforced polymers produced through FDM have significantly improved and thus become appealing in load-bearing uses of low weight in the automotive and aerospace industries [\u003cspan additionalcitationids=\"CR4 CR5 CR6\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePolyhydroxyalkanoates (PHA), which is a biodegradable and sustainable thermoplastic, has come to fill the gap with conventional polymers like ABS that are petroleum-based. Eco-friendly polymer composites are developed in line with green manufacturing, in which natural and bio-derived reinforcements are also studied [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In this regard, Kevlar fiber-reinforced PHA composites are environmentally friendly with high mechanical performance. It has been previously reported that the wear resistance when using KF-polymer composites is greatly enhanced by the addition of nano-fillers, thereby making them useful in dynamically loaded mechanical components [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Also, the polymer composites made by 3D-printing have been utilized in aerodynamic optimization literature with notable success, which shows the adaptability of the FDM-made polymer structures [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIt has also been demonstrated that the inclusion of fiber reinforcements increase flexural strength, resistance to moisture and long term durability in polymer composites even those reinforced with natural fibers such as bamboo and glass fiber waste [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The most frequently extruded polymers in FDM are PHA and ABS because they exhibit a good rheological response and can be easily extruded using filament systems [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Modern technology in FDM has seen the creation of composite filaments, open-source extrusion machines like Recycle Bot, which allows to formulate materials in custom ways and have environmental-friendly production processes [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. FDM process is similar, that is, CAD models are converted into STL files and then deposited into layers through material deposition using computer-controlled tool paths [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe incorporation of Kevlar fibers in the PHA mat modulates thermal properties and reduces FDM undesired effects like warping and dimensional errors, and also adds strength and load-carrying capability to the FDM system and fracture strength [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. A number of studies have shown significant tensile, flexural, impact, and wear enhancement of KF-reinforced PHA composites, which broadens their application in aerospace, automotive, robotic, and biomedical applications [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Additional optimization of material performance is possible by regulating the fabrication procedures of the filaments, fiber volume ratio as well as extrusion conditions in order to obtain the optimal balance of material performance and cost efficiency [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFDM has a broad range of thermoplastic composites which can be processed and thus have a wider application in industry and not limited to prototyping. In the latest research, the focus on the investigation of new materials and superior printing approaches to increase the durability, functionality, and the service life of FDM-printed parts can be noticed [\u003cspan additionalcitationids=\"CR21 CR22\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Taguchi and ANOVA are design of experiments (DOE) methods that have been used extensively to optimize printing variables such as layer height, print speed and infill density leading to large gains in the tensile strength of PHA-based composites [\u003cspan additionalcitationids=\"CR25 CR26\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Such optimized conditions have enabled the PHA composites to be used in high-performance applications in aerospace, automotive and in the medical field.\u003c/p\u003e \u003cp\u003eSuch experimental work has been done on the enhancement of fiber-matrix interfacial bonding, and optimization of Kevlar fiber roving diameter in KF-PHA composites and significant improvements have been made with tensile and flexural strength results [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. In comparative research on polypropylene/ glass fiber composite produced through FDM and compression molding, it has been established that processing paths have a strong effect on crystallinity and mechanical performance [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The reinforcement of thermoplastic polyurethane (TPI) filaments in short and continuous kinetic force (KF) is also investigated and the findings show considerable tensile strength improvement in comparison to un-reinforced materials [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe mechanical characterization of FDM fabricated KF-PHA composites is normally performed through ASTM standards, such as tensile, flexural, impact, hardness, and wear tests. Detailed testing systems like the four point bending of curved and L-shaped samples have been utilized to test performance under the realistic service environment [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. It was demonstrated to be additive, in that with the addition of chopped, continuous Kevlar fibers, thermo-mechanical properties such as tensile strength, flexural modulus and hardness are improved, and that complex geometries may be fabricated in a relatively short period of time [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eRecent research of continuous Kevlar fiber reinforced polymer (CKFRP) composites underscores the extreme importance of layer thickness, print orientation and extrusion conditions on the mechanical performance [\u003cspan additionalcitationids=\"CR35 CR36\" citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Continuous Kevlar fiber deposition Systems based on dual-nozzle FDM have been reported to report high tensile strength with increasing fiber volume fraction [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. Also, research on thin-walled KF PHA samples highlights the importance of printing orientation and material structure to achieve maximum structural efficiency [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. Kevlar fiber reinforcement has been useful in stabilizing PHA-based components during printing and service to overcome some problems like warping and deformation of the materials [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTaken altogether, these investigations highlight the possible use of Kevlar fiber-reinforced PHA composites in additive manufacturing. The combination of sustainable material use, fiber reinforcement, and optimum process makes FDM-based KF-PHA composites promising to be used in high-performing, lightweight, and environmental-friendly engineering use.\u003c/p\u003e"},{"header":"2. Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Materials\u003c/h2\u003e \u003cp\u003ePolyhydroxyalkanoates (PHA) are biodegradable thermoplastic polyester polymers produced by microorganisms through renewable carbon sources as sugar, fats and oils. PHA\u0026rsquo;s have been receiving growing popularity as alternative materials to petroleum-based polymers in additive manufacturing because of their bio-based source and environmentally compatible properties. Although there are some constraints of thermal stability and post-processing procedures, PHA has extensive application in Fused Deposition Modeling (FDM) due to the relatively low cost, low melting temperature, sufficient mechanical strength, minimal thermal shrinkage during printing, and facilitating intrusiveness. Nevertheless, PHA has a relatively low heat defiance amid widely used FDM polymers, and post-print annealing is required to improve its thermal and dimensional performance. The PHA resin in the current work is sourced from Akruthi Bioresins Impex Pvt. Ltd., Bengaluru, Karnataka, India.\u003c/p\u003e \u003cp\u003eKevlar fibers are high performance synthetic fibers made of long chain aromatic polyamides (aramids), and have an average filament diameter of between 10 m\u0026thinsp;\u0026minus;\u0026thinsp;12 m. Kevlar fibers are characterized by very high tensile strength, high strength to weight ratio, high stiffness, high chemical resistance, thermal stability and very low coefficient of thermal expansion. Due to these characteristics, Kevlar fibers find widespread application in aerospace elements, civil engineering construction, military protection, and sports gear of high performance. The Kevlar Fibres used in the current work is sourced from Go Green Products Pvt. Ltd., Chennai, India.\u003c/p\u003e \u003cp\u003eKevlar-fiber-reinforced polymers (KFRPs) are developed by embedding Kevlar fibers into polymer matrix to produce lightweight materials that are very rigid and have better load-bearing capacity. Nevertheless, the composites can be brittle because of the concentration of stress at the interface of the fiber and the matrix. Quick heating and cooling in the process of the deposition of fiber-reinforced PHA composites made using the FDM process result in residual thermal stresses, which may cause defects including warping, buckling and dimensional distortion. Post-print annealing is very essential in alleviating these internal stresses, enhancing the interfacial bonding, increasing dimensional stability and the general mechanical performance of the composite structures. The Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e gives the properties of PHA and Kevlar Fibre used in the current work.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eProperties of PHA and Kevlar Fibre\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProperty\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePHA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eKevlar Fiber\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDensity (g/cm\u0026sup3;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.24\u0026ndash;1.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.76\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTensile strength (MPa)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48\u0026ndash;115\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e~\u0026thinsp;3530\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTensile modulus (GPa)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.0\u0026ndash;4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e~\u0026thinsp;230\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStrain to failure (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5\u0026ndash;10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e~\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMelting / Decomposition temperature (\u0026deg;C)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e150\u0026ndash;160\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e180\u0026ndash;190*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePHA-Kevlar fiber composite filaments were made in the current research with 0 wt. %, 10 wt. % and 20 wt. % Kevlar fiber weight fractions. Before the fabrication, the Kevlar fiber and PHA weight ratios were calculated correctly. The sample KF0 was composed of 100% PHA (1000 g). In the KF10 composite, there was 100 g of Kevlar fiber and 900 g of PHA whereas in the KF 20 composite, there were 200 g of Kevlar fiber and 800 g of PHA.\u003c/p\u003e \u003cp\u003eParametric Creo 2020 software was used to design test samples and was exported in the form of stereo lithography files (.STL). The STLs were sliced with the cura slicing software in which the printing parameters including the layer height (0.2 mm), nozzle temperature, and bed temperature were adjusted. The fabrication of the specimens was conducted with the help of a 3D Print kart FDM printer that has a more stable mechanism and better surface finish, as well as a convenient interface in comparison to printers of previous generations. Transfer of the sliced files was made to the printer through the USB flash drive and the printing was done by feeding the filament of composite through the extruder, which was then melted and deposited through the nozzle in a layer-by-layer fashion. The build platform was cleared after removal, the support structures, and the printed specimens were then detached and the samples were made ready to undergo mechanical characterization.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Methodology\u003c/h2\u003e \u003cp\u003eThe manufacturing and testing of PHA-Kevlar fiber reinforced polymer composites was done through fused deposition modeling (FDM) technique. The choice of printing parameters was informed by material choice, pre-experiments and literature sources in order to achieve consistent extrusion and sample fabrication without defects. All specimens were printed with an industrial-level 3D Printzkart FDM printer under conditions of controlled ambient environment. The printing was done through the preparation of the CAD models in Parametric Creo 2020 that were put into stereolithography (.STL) files that were then entered into Cura slicing software. A USB interface was used to feed the sliced files to the printer, and the composite filament into the extruder, where it was heated and deposited in layers by a constant layer thickness of 0.2 mm by a heated nozzle with a constant print speed, infill density and raster orientation.\u003c/p\u003e \u003cp\u003eMechanical characterization of the specimens was then conducted to determine the effect of Kevlar fiber reinforcement and printing parameter on the composites performance following fabrication. The tensile and flexural tests together with the impact and wear tests were performed based on the ASTM standards to make the results reliable and comparable. Tensile test was conducted according to ASTM D638 [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e] on a universal testing machine and specimens that had a total length of 165 mm and a maximum width of 19 mm with a width of 3.2 mm were tested to fracture (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The test configuration was used to provide accurate load application, crosshead speed, and measure load-extension behavior, and errors caused by misaligning specimens or slippage at the grips were kept to a minimum.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe flexural properties were tested on rectangular specimens that were made as per the ASTM D7264 standards [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. The sample size (125 mm x 12.7 mm x 3.2 mm) was 3D printed using the CAD model as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, and then placed into the testing setup of three-point bending to find the flexural strength. The test results were justified by all the tested specimens fracturing within the acceptable strain limit of 5% which is given by ASTM D790 [\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eImpact resistance was found using notched specimens manufactured as per the ASTM D256 requirements [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]. The specimens were 64 mm x 12.7 mm x 3.2 mm in size and had a V-notch of 45\u003csup\u003eo\u003c/sup\u003e angle cut below the top edge at the center as shown in the Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Impact tests were done in order to measure the energy absorbed by the material in sudden loading conditions which helped to understand the toughness of the PHA-Kevlar fiber composites.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe Taguchi\u0026rsquo;s design of experiments (DoE) approach was utilized in order to maximize the mechanical performance of the composites with the help of MINITAB 17 software [\u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e63\u003c/span\u003e]. To reduce the amount of experimental trials, an L27 orthogonal array [\u003cspan additionalcitationids=\"CR46\" citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e] was chosen to study the effect of four FDM process parameters at three levels, which provides statistical significant results. The factors and the parametric levels used in the DoE is given in Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eFactors and Parametric Level used in Taguchi\u0026rsquo;s DoE in the present work\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFactor\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLevel 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLevel 2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLevel 3\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePrinting speed (mm/s)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInfill density (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBuild orientation (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eKevlar Fibre (Wt. %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe analysis of signal-to-noise (S/N) ratio was done based on the larger-the-better criterion of mechanical properties including tensile strength, flexural strength, and impact energy. An increase in the S/N ratios showed more strength of the process and decreased the sensitivity to the noise factors [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]. The most influential parameters were revealed with the help of response tables and main effect plots in order to find the best combinations of these parameters.\u003c/p\u003e \u003cp\u003eFurthermore, a detailed DoE analysis was conducted to analyze the generated relationship between input factors and the output reactions in the FDM process. Data collection, statistical analysis and interpretation of results were done in a systematic manner to determine the stability and capability of processes [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. The signal to noise ratio acted as a guide that there was preeminence of factors that are controllable over those that are noise factors and that there is a need to overpower the design and reduce the variability [\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e]. The tables of responses that were produced by the DoE have given quantitative ranking of the process parameters, which is important in determining how the process parameters influence the mechanical performance in addition to guaranteeing that the optimized conditions produced stable, repeatable, and reliable composite fabrication.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and Discussion","content":"\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Tensile Test Results\u003c/h2\u003e \u003cp\u003eThe Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e summarizes the tensile test results and depicts as to how printing speed, build orientation, infill density and Kevlar fiber (KF) affects the mechanical response of PHA-based composites fabricated through FDM. 27 specimens were tested, which represents an L27 Taguchi orthogonal array (OA), and it was possible to systematically assess the chosen process parameters and the material compositions.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTensile Test Results as per Taguchi\u0026rsquo;s L27 Orthogonal Array\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample no\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSpeed (mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOrientation (\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eInfill Density (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKF (Wt.%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eUltimate Load (kN)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eUltimate Tensile Strength (MPa)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eElongation\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e84.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e74.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e103.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e52.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.89\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e66.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e84.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.64\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e90.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.89\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e87.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e90.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e97.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.80\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e58.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e92.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e82.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e84.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e84.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e60.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e84.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e87.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e95.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e87.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e104.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e76.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e66.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e79.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e92.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e82.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e92.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1.89\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIn every specimen, final tensile strength (UTS) and final load were highly influenced by the infill density and the content of Kevlar fibers. The specimens that were printed with 100% infill usually had a better load bearing capacity and tensile strength than their 60% to 80% counterparts, which showed better load transfer internally and a lower porosity. Sample coils with 20 wt.% Kevlar fiber and infill density of 100% showed the highest tensile strengths with maximum UTS values of between 103 MPa and 105 MPa (Samples 3 and 21). This verifies the positive action of Kevlar fiber reinforcement to the strength of PHA composites in circumstances where continuity of the material is achieved in adequate numbers. The speed of printing also had an impact on tensile behavior, but the effect was not so significant as infill density and KF content. Moderate printing speeds (60\u0026ndash;80 mm/s) had the propensity to create greater ultimate loads and tensile strengths in comparison with those lower in speed, indicating enhanced interlayer bonding and stability of filament deposition at these settings. With neat PHA (0 wt.% KF), tensile strength values generally fell within 80 MPa to 98 MPa, with the highest ratio of elongation (up to about 3.8%) at the lower infill densities and advantageous to the build positions, which was indicative of more ductile behavior. Build orientation also gained a great influence on tensile performance because the FDM process is inherently anisotropic. The tensile strength and ultimate load of specimens printed at 0\u003csup\u003eo\u003c/sup\u003e orientation tended to be stronger than those at 45\u003csup\u003eo\u003c/sup\u003e and 90\u003csup\u003eo\u003c/sup\u003e orientation of the printing since the load was pointed to the direction of filament deposition. Conversely, the tensile strength of samples printed at 45\u003csup\u003eo\u003c/sup\u003e orientation was relatively lower, which is explainable by the fact that, the interlayers shear would be higher and the bonding along the load path will be less favorable. Break elongation declined significantly with more content of Kevlar fibers. Neat PHA samples had more elongation values, with values up to 3.8 wt. %, but composites with 10 wt. % and 20 wt. % KF had lower values of elongation. This decrease in ductility can be linked to the rigidity and brittle character of Kevlar fibers that prevents chain mobility in polymer and causes fracture sooner in response to tensile stress [\u003cspan additionalcitationids=\"CR51\" citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Flexural Test Results\u003c/h2\u003e \u003cp\u003eThe flexural test data of the PHA and PHA-Kevlar fiber (KF) composite specimens manufactured via FDM process under different printing velocities, print build orientations, infill densities, and Kevlar fiber content is presented in the Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. The experimental matrix is composed of 27 samples according to L27 Taguchi orthogonal array, to allow a systematic study of the joint action of processing and material parameters on peak load and flexural strength [\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eFlexural Test Results as per Taguchi\u0026rsquo;s L27 Orthogonal Array\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample no\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSpeed (mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOrientation (\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eInfill Density (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKF (Wt.%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePeak Load (kN)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFlexural Strength (MPa)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e256.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e76.44\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e195.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e58.42\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e249.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e74.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e271.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e81.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e237.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e70.73\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e250.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e74.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e267.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e79.68\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e231.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e69.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e256.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e75.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e283.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e84.65\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e247.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e73.71\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e317.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e94.84\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e277.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e82.66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e237.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e70.98\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e327.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e97.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e276.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e82.41\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e254.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e75.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e256.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e79.68\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e275.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e82.29\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e246.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e73.59\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e278.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e83.03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e291.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e86.76\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e284.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e84.90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e256.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e76.69\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e290.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e86.64\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e256.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e76.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e271.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e80.92\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe findings reveal that printing speed and infill density have a strong effect on both the peak load and flexural strength. Generally, the flexural performance of specimens with higher infill densities was better because with high material continuity and low internal porosity there was a higher resistance to bending loads. Sample 15, which was printed at a speed of 60 mm/s, 45\u003csup\u003eo\u003c/sup\u003e orientation, and 100% infilled with neat PHA gave the highest flexural strength of 97.70 MPa. There were also high flexural strengths that were found when the sample was printed at 60 mm/s and with 100% infill density, like Sample 12, with the flexural strength of 94.84 MPa, a condition indicating the best processing conditions.\u003c/p\u003e \u003cp\u003eThe speed of printing was an important factor in flexural behavior pattern. Samples printed at moderate rate of 60 mm/s had a steady high peak loads and flexural strengths than those that were printed at rate of 40 mm/s and those that were printed at rate of 80 mm/s. The implied trend is that a medium rate of printing fosters enhanced interlayer fusion along with uniform filament deposition, which are vital in enhancing the bending resistance.\u003c/p\u003e \u003cp\u003eThe orientation of the building also influenced flexural characteristics because the FDM-printed pieces were anisotropic. Experiments run at low temperatures (0\u003csup\u003eo\u003c/sup\u003eC ) and orientations (45\u003csup\u003eo\u003c/sup\u003eC) tended to have a better flexural strength than those run at high temperatures (90\u003csup\u003eo\u003c/sup\u003eC) because the alignment of the filament was more favorable relative to stresses applied during bending. Nevertheless, orientation-related weaknesses were partially alleviated with the incorporation of the Kevlar fiber through which a few 90\u003csup\u003eo\u003c/sup\u003e oriented composite specimens were able to record competitive values of flexural strength.\u003c/p\u003e \u003cp\u003eFlexural performance was found to be dependent on the content of Kevlar fibres throughout the entire dataset [\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e]. Peak loads under comparable processing conditions were frequently also higher in composites with 10 wt. % and 20 wt. % KF than in neat PHA specimens, which is due to the reinforcing nature of Kevlar fibers. However, the increase in flexural strength did not directly relate to the fibre content implying that other factors like fiber distribution, interfacial bonding and print parameters are also important factors [\u003cspan additionalcitationids=\"CR56\" citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.3 Impact Test Results\u003c/h2\u003e \u003cp\u003eThe Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e summarizes the impact test findings of FDM-printed PHA and PHA-Kevlar fiber (KF) composite samples fabricated at varying printing speed, build orientation, infill densities and Kevlar fiber contents according to L27 Taguchi experimental set up [\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e]. Impact energy is the capacity of the material to take energy when suddenly loading and it is a measure of toughness expressed in joules.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eImpact Test Results as per Taguchi\u0026rsquo;s L27 Orthogonal Array\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSpeed\u003c/p\u003e \u003cp\u003e(mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOrientation\u003c/p\u003e \u003cp\u003e(\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eInfill\u003c/p\u003e \u003cp\u003eDensity (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKF\u003c/p\u003e \u003cp\u003e(Wt.%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eImpact\u003c/p\u003e \u003cp\u003eEnergy (J)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.35\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.65\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.55\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.45\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.35\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.40\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.75\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.55\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.35\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.65\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThere is an obvious trend which seems to remain the same in regard to infill density. The samples that have been printed with 100% infill contain the most considerable impact energy in all the printing speed and orientations with about 80% and 60% infill. This is because of decreased internal porosity and better load distribution in harder structures, which leads to increased resistance to crack initiation and propagation during impact loading.\u003c/p\u003e \u003cp\u003eThe impact performance of Kevlar fiber reinforcement is very strong. The composites with 20 wt.% KF would always have higher impact energy than that of 10 wt.% KF composites and neat PHA. The enhanced toughness is linked to energy-absorbing processes including fiber pull-out, crack bridging, and interfacial debonding, which is more efficient in dissipating the impact energy as compared to the polymer matrix itself. Although the neat PHA samples have relatively higher ductility, they have low impact energy since they lack the fiber-based toughening mechanisms.\u003c/p\u003e \u003cp\u003eThe influencing effect of the printing speed on the impact energy is moderate. Sample specimens made at 60 mm /s and at 80mm/s tend to show a better impact resistance than those printed at 40mm/s, indicating better interlayer fusion and enhanced bonding at moderate to high deposition rates. Nevertheless, the influence of printing speed is not that dominant as infill density and Kevlar fiber content.\u003c/p\u003e \u003cp\u003eImpact behavior is also influenced by build orientation, but not so much. Printed samples at a 45\u003csup\u003eo\u003c/sup\u003e orientation and 90\u003csup\u003eo\u003c/sup\u003e orientation are more likely to absorb the impact energy as compared to the 0\u003csup\u003eo\u003c/sup\u003e orientation especially in Kevlar-reinforced composites. This is explained by the presence of modified crack paths and the increase of energy dissipation due to fiber-matrix interactions in the case of off-axis loading.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.4 Parametric Optimization of Test Results\u003c/h2\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e3.4.1 Ultimate Tensile Strength\u003c/h2\u003e \u003cp\u003eThe parametric optimization using Taguchi\u0026rsquo;s analysis indicated that the infill density has the greatest impact on the final tensile strength (UTS) of FDM-printed PHA-Kevlar fiber composites, with build orientation second and Kevlar fiber content third, and printing speed had the least effect [\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e]. The larger-is-better criterion of signal-to-noise (S/N) ratio analysis showed that the best choice of parameters to maximize UTS is high printing speed (Level 3), 100% infill density (Level 3), 0, build orientation (Level 1), and increased Kevlar fiber reinforcement. This mix will guarantee a better filament continuity, efficient load alignment, and an increase in the fiber-matrix stress transfer. The Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e gives the Response table for mean values, while the Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e gives the response table for S/N ratio. The S/N ratio results were further supported by the corresponding response table of means whereby there was a significant increment in the average tensile strength at increased infill densities and both positive and negative build orientations. Printed samples with 100% infill experienced the greatest mean UTS and this validates the importance of dense internal structures in reducing voids and enhancing load-bearing capacity. Incorporation of Kevlar fiber made tensile strength much higher than that of neat PHA, though the improvement was at the expense of ductility; this is in line with the stiff and brittle properties of aramid fibers.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResponse table for mean values for UTS\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePrinting\u003c/p\u003e \u003cp\u003eSpeed (mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInfill\u003c/p\u003e \u003cp\u003eDensity (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBuild\u003c/p\u003e \u003cp\u003eOrientation (\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKevlar\u003c/p\u003e \u003cp\u003eFiber (wt. %)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e81.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e88.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e86.74\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e81.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e76.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e75.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e77.90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e86.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e91.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e85.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e84.56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDelta\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4.85\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e14.27\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e13.38\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e8.84\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRank\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResponse table for S/N ratio for UTS\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePrinting\u003c/p\u003e \u003cp\u003eSpeed (mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInfill\u003c/p\u003e \u003cp\u003eDensity (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBuild\u003c/p\u003e \u003cp\u003eOrientation (\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKevlar\u003c/p\u003e \u003cp\u003eFiber (wt. %)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e38.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e38.75\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e37.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e37.69\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e38.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e38.39\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDelta\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e0.58\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1.53\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e1.39\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1.06\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRank\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe SN ratio and interaction plot analysis in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e show that there is a significant interaction between infill density and build orientation and also between infill density and Kevlar fiber content. Kevlar fiber strengthening effect was the greatest at the increase in infill densities, which suggests that sufficient material continuity is a critical requirement in efficient stress transfer between the fiber and the polymer matrix. Relationships with printing speed were rather weak indicating that the effect on UTS is quite independent in the parameter range of study.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e \u003ch2\u003e3.4.2 Flexural Strength\u003c/h2\u003e \u003cp\u003eThe response matrix in Table\u0026nbsp;\u003cspan refid=\"Tab8\" class=\"InternalRef\"\u003e8\u003c/span\u003e and Table\u0026nbsp;\u003cspan refid=\"Tab9\" class=\"InternalRef\"\u003e9\u003c/span\u003e show how the printing speed, infill density, orientation of the build, and Kevlar fiber content affect the desired mechanical response using the signal-to-noise (S/N) ratio analysis and mean response values depending on the Taguchi larger-is-better criterion. These tables are employed to see an approximate importance of every process parameter and to select the best levels of factors that will facilitate an improved performance. S/N ratio response table shows that the density of the infill has the most significant effect on the response as the delta of 1.14 is the highest and it\u0026rsquo;s Rank of 1. This shows how the internal material continuity and low porosity are very vital when it comes to enhancing the stability and uniformity of the mechanical performance. The speed of printing is second with a delta value of 1.01, with a relatively large but relatively less significant impact on the response. The content of Kevlar fiber is the third one, and it is rated as a moderate delta of 0.44, which means that fiber reinforcement does not dominate but has a contributing role in the studied range of infill density and printing speed. Build orientation presents the least impact with the minimal delta of 0.33 and thus it occupies the fourth position. The trend in the S/N ratio analysis is also further supported by the response table of mean values. The infill density once again appears to be the most significant parameter with the largest delta value of 9.85 and the Rank 1. This proves that the more the infill, the higher the average mechanical response. The second rank is of printing speed with 9.13 delta value which means that it had an enormous impact on the mean response. The third one is the content of Kevlar fiber whose delta of 3.87 indicates its contribution to the strength of the composite and the least influential factor is the build orientation, which has the lowest delta value of 2.76.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab8\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 8\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResponse table for S/N ratio for Flexural Strength\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePrinting\u003c/p\u003e \u003cp\u003eSpeed (mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInfill\u003c/p\u003e \u003cp\u003eDensity (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBuild\u003c/p\u003e \u003cp\u003eOrientation (\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKevlar\u003c/p\u003e \u003cp\u003eFiber (wt. %)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e37.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e37.95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e38.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e37.68\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e37.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e38.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDelta\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1.01\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1.14\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.33\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.44\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRank\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab9\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 9\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResponse table for mean values for Flexural Strength\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePrinting\u003c/p\u003e \u003cp\u003eSpeed (mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInfill\u003c/p\u003e \u003cp\u003eDensity (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBuild\u003c/p\u003e \u003cp\u003eOrientation (\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKevlar\u003c/p\u003e \u003cp\u003eFiber (wt. %)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e73.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e82.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e77.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e79.34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e82.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e80.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e76.97\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e81.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e78.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e80.84\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDelta\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e9.13\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e9.85\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e2.76\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e3.87\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRank\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe Taguchi method was applied to maximize flexural strength of PHA-Kevlar fiber composites fabricated using the FDM technique, given that the larger-is-better signal-to-noise (S/N) ratio [\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e]. The dominating impacts that the infill density has on the flexural performance are shown in the main effects plot in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e, where the higher the S/N ratios at the higher levels of infill because of the better continuity of the material and lower internal porosity. The rate of printing also has an apparent influence, and a median rate of printing the material provides a higher flexural strength due to better bonding between layers. The orientation of the building has a relative smaller effect, but specimens that are patterned in the middle have better bending resistance. The content of Kevlar fibers has a positive effect on flexural strength, and the increased reinforcement level increases the stiffness and carrying capacity.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe interaction plots in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e indicate that the density of the infill is also much in interaction with printing speed and Kevlar fiber content. The positive reinforcement of Kevlar fibre increases with the increase in infill density, which means the reinforcement of the stress is more effective in the denser structure. Likewise, a more optimized printing speed gives improved flexural performance with an increase in infill density. In general, the Taguchi analysis confirms that infill density is the most important factor determining flexural strength, then is printing speed and content of Kevlar fibers, and secondary is the build orientation. The agreement of the main effects and interaction patterns illustrates that Taguchi methodology is effective in optimization of flexural performance in PHA Kevlar fiber composites manufactured through FDM.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e \u003ch2\u003e3.4.3 Impact Strength\u003c/h2\u003e \u003cp\u003eThe S/N ratio response matrix in Table\u0026nbsp;\u003cspan refid=\"Tab10\" class=\"InternalRef\"\u003e10\u003c/span\u003e shows that the element that has the most impact is the content of Kevlar fiber content since it has the maximum delta of 5.2501 and is ranked at the top. This shows how the reinforcement of fiber prevails in enhancing the strength and steady-ness of the reaction. Infill density comes second with a delta value of 5.1718, which shows that it has a strong contribution, because it has high material continuity and low internal porosity. The third most influential element is printing speed which has a moderate impact on the response with build orientation having the least impact as indicated by the smallest delta value of 1.5516 and the fourth ranking.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab10\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 10\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResponse table for S/N ratios for Impact Strength\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePrinting\u003c/p\u003e \u003cp\u003eSpeed (mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInfill\u003c/p\u003e \u003cp\u003eDensity (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBuild\u003c/p\u003e \u003cp\u003eOrientation (\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKevlar\u003c/p\u003e \u003cp\u003eFiber (wt. %)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026minus;0.4109\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026minus;1.4681\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.3250\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026minus;1.2748\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.3327\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.1402\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.1742\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.6752\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.4539\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.7037\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.8766\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.9753\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDelta\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2.8648\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e5.1718\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e1.5516\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e5.2501\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRank\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe trends in the analysis of S/N ratio are supported by the response of means in Table\u0026nbsp;\u003cspan refid=\"Tab11\" class=\"InternalRef\"\u003e11\u003c/span\u003e. Once again, the content of Kevlar fiber becomes the most important, with the greatest delta of 0.6944, which validates the fact that the marked increase in the reinforcement with fiber contributes to the significant change in the mean response. The next in rank with a delta of 0.6611 is the infill density which supports its significance in increasing the mechanical performance. Printing speed has a moderate impact with a delta of 0.3333 and the meaning of building orientation has little impact on the mean response as shown by the least delta of 0.0833.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab11\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 11\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResponse table for means for Impact Strength\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePrinting\u003c/p\u003e \u003cp\u003eSpeed (mm/s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInfill\u003c/p\u003e \u003cp\u003eDensity (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBuild\u003c/p\u003e \u003cp\u003eOrientation (\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKevlar\u003c/p\u003e \u003cp\u003eFiber (wt. %)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026minus;0.4109\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026minus;1.4681\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.3250\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026minus;1.2748\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.3327\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.1402\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.1742\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.6752\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.4539\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.7037\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.8766\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.9753\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDelta\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2.8648\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e5.1718\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e1.5516\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e5.2501\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRank\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e shows the plot of the key effects of signal-to-noise (S/N) ratios of impact strength using the larger-is-better criterion. As the plot depicts, infill density and Kevlar fiber content affect the impact performance the most as shown by the steep rise in S/N ratio with the rise in level of the two parameters. Optimal S/N ratios are realized at 100% infill density and 20 wt. % Kevlar fiber, and this implies that toughness is enhanced by decreased internal voids and that fiber-based energy dissipation mechanisms are effective. Speed of printing also gives a positive impact and it is higher the speed of printing, the higher the S/N ratios, indicating a better bond between layers. Build orientation has a relatively lower impact, but higher orientations have a marginal increase in impact performance.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e shows the interaction graph of the S/N ratios of impact strength, showing the interaction of the printing speed, infill density, build orientation, and the amount of Kevlar fibers. It has been found that the infill density and the content of Kevlar fibers have strong interactions in such a way that the positive influence of fiber reinforcement is more pronounced in denser structures. The relations between printing speed and infill density also display that the higher printing speed, the more efficient is its combination with high infill density in terms of improving impact strength. The interaction patterns also reveal that Kevlar fiber reinforcement nullifies the effects of build orientation resulting in the enhancement of impact resistance in varying directions of printing. On the whole, the interaction plot proves that the strength of impact is controlled by the synergistic effects of the material composition and process parameters, but the infill density and content of Kevlar fibers are the most important [\u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e63\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eThe Taguchi-based parametric optimization has a great impact on the mechanical performance of FDM-fabricated PHA composites. The tensile strength, flexural strength and impact resistance increased significantly as a result of introducing optimum Kevlar fiber and choosing appropriate infill density thus supporting the appropriateness of aramid fiber reinforcement to biodegradable polymer systems.\u003c/p\u003e\n\u003cp\u003eThe results of tensile tests indicated that the ultimate tensile strength rose to more than 100 MPa when there was 20 wt. % Kevlar fiber in the composite at 100% infill density and optimal orientation of the build. Flexural strength behaved in the same way with a maximum of 97.7 MPa and this means that there is a better ability to resist bending forces because of greater fiber-matrix stress transfer. Kevlar fiber addition to the impact performance showed that the maximum absorbed energy went up to levels that were less than 0.5 J in the low-infill neat PHA specimen, and up to around 2.25 J in the highly reinforced fully dense composites.\u003c/p\u003e\n\u003cp\u003eTaguchi signal to noise analysis and mean response analysis continuously determined infill density to be the largest factor affecting tensile and flexural strength (Rank 1) then Kevlar fiber content then printing speed and then build orientation had the lowest influence. In the case of impact strength, the most important parameter was Kevlar fiber content, and the delta value of both the tables of S/N ratios and mean response was maximum. The combination of parameters, which was predicted by the Taguchi method as the best, higher infill density, more Kevlar fibers and moderate-high speed of printing, confirmed the adequacy of the optimization technique.\u003c/p\u003e\n\u003cp\u003eGenerally, the experiment confirms that systematic Taguchi optimization, with Kevlar fibers reinforcement is a relevant approach to customize the mechanical characteristics of biodegradable PHA composites manufactured through FDM. The optimized PHA-kevlar fiber composites can be used in lightweight, load-bearing, and impact-resistant engineering applications with mechanical properties, which are comparable to synthetic polymers.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics Statement:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\"The research aims to contribute to academic knowledge while upholding the highest ethical standards in data collection and analysis.\"\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThis research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\"Data supporting the research work is embedded within the manuscript, and any additional data related to work can be obtained upon requisition to the corresponding author.\"\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eauthor’s contribution statement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization, S.N. and P.B.A.; methodology, S.N., P.B.A., and A.F.; formal analysis, S.N. and R.K.; investigation, S.N. and R.K.; data curation, R.K.; writing—original draft preparation, S.N.; writing—review and editing, P.B.A., R.K., and A.F.; visualization, A.F.; supervision, P.B.A.; project administration, P.B.A.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAll authors have read and agreed to the author’s contribution statement and herewith abide by the publication ethics and guidelines.\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Initials:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eS.N.: Santhosh Nagaraja;\u003c/p\u003e\n\u003cp\u003eP.B.A.: Praveena Bindiganavile Anand;\u003c/p\u003e\n\u003cp\u003eR.K.: Ramesha Kodandappa;\u003c/p\u003e\n\u003cp\u003eA.F.: Adisu Frinjo.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eNorizzati Z, Dhar S, Siti M, Hajar Sheikh Md, Zaleha F, Mustafa KamarulAriffin, Zakaria SS (2019) Effect of water Prashar, G., Vasudev, H. and Bhuddhi, D. (2023). Additive manufacturing: Expanding 3D printing horizon in Industry 4.0, Int. J. Interact. Des. Manuf. (IJIDeM), 17, pp. 2221\u0026ndash;2235. DOI: 10.1007/s12008-022-00956-4.\u003c/li\u003e\n \u003cli\u003eTofail, S.A., Koumoulos, E.P., Bandyopadhyay, A., Bose, S., O\u0026rsquo;Donoghue, L. and Charitidis, C. (2018). Additive manufacturing: Scientific and technological challenges, market uptake and opportunities, Materials Today, 21, pp. 22\u0026ndash;37. DOI: 10.1016/j.mattod.2017.07.001.\u003c/li\u003e\n \u003cli\u003ePraveena, B.A., Lokesh, N., Buradi, A., Santhosh, N., Praveena, B.L. and Vignesh, R. (2023). A comprehensive review of emerging additive manufacturing (3D printing technology): Methods, materials, applications, challenges, trends and future potential, Materials Today: Proceedings. DOI: 10.1016/j.matpr.2021.11.059.\u003c/li\u003e\n \u003cli\u003eXames, M.D., Torsha, F.K. and Sarwar, F. (2023). A systematic literature review on recent trends of machine learning applications in additive manufacturing, Journal of Intelligent Manufacturing, 34, pp. 2529\u0026ndash;2555. DOI: 10.1007/s10845-022-01957-6.\u003c/li\u003e\n \u003cli\u003eLokesh, N., Praveena, B.A., Reddy, J.S., Kedambadi Vasu, V. and Vijaykumar, S. (2021). Evaluation on effect of printing process parameters through Taguchi approach on mechanical properties of 3D-printed PLA specimens using FDM at constant printing temperature, Materials Today: Proceedings.\u003c/li\u003e\n \u003cli\u003eYadav, S.P.S., Shankar, V.K., Avinash, L., Buradi, A., Praveena, B.A., Kedambadi Vasu, V., Vinayaka, N. and Dilip Kumar, K. (2022). Development of 3D printed electromyography controlled bionic arm, In: Pai, P.S. and Krishnaraj, V. (Eds.), Sustainable Machining Strategies for Better Performance, Lecture Notes in Mechanical Engineering, Springer, Singapore.\u003c/li\u003e\n \u003cli\u003eLokesh, N., Reddy, J.S., Praveena, B.A., Kishore, Y.M., Veeresh, B., Acharya, S.B., Kapse, J.E., Nadig, P.P. and Prasad, M. (2022). Evaluation and optimization of process parameters for surface roughness of 3D-printed PETG specimens using Taguchi method at constant printing temperature, In: Pradhan, P., Pattanayak, B., Das, H.C. and Mahanta, P. (Eds.), Recent Advances in Mechanical Engineering, Lecture Notes in Mechanical Engineering, Springer, Singapore.\u003c/li\u003e\n \u003cli\u003eJoseph, K., Jangam, S., Ramesha, K., Umesh, V., Kumar, G.V., Santhosh, N., Shankar, G., Razak, A., Afzal, A. and Praveena, B.A. (2022). Design and optimization of the process parameters for fused deposition modelling by experimental and finite element approach, AIP Conference Proceedings, 2421, Article 040004. 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Impact of Graphene Nano particles on static and dynamic mechanical properties of basalt-glass fibre reinforced epoxy polymer hybrid composites. Advances in Materials and Processing Technologies, 1\u0026ndash;25. https://doi.org/10.1080/2374068X.2024.2424032.\u003c/li\u003e\n \u003cli\u003eAnand, P. B., Aswathanarayan, M. S., Nagaraja, S., Chandrashekar, A., Shivakumar, H. D., Nugroho, S., \u0026amp; Ammarullah, M. I. (2024). Synthesis and Characterization of Mechanical Properties of Dammar Gum-Epoxy Bio-Composites with Areca Nut Husk and Banana Fiber as Reinforcements for Biomedical Applications. Journal of Chemical Engineering of Japan, 57(1). https://doi.org/10.1080/00219592.2024.2438111\u003c/li\u003e\n \u003cli\u003eJagadeesan, N., Selvaraj, A., Nagaraja, S., Abbas, M., Saleel, C. A., Aabid, A., \u0026amp; Baig, M. (2022). Response Surface Methodology Based Optimization of Test Parameter in Glass Fiber Reinforced Polyamide 66 for Dry Sliding, Tribological Performance. 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Fabrication and Characterization of Tensile Properties of Aluminum 5083/Silicon Carbide/Fly Ash Composites for Advanced Engineering Applications. Journal of Polymer \u0026amp; Composites, 6(2), 6-9.\u003c/li\u003e\n \u003cli\u003eRamesha, K., Sudersanan, P.D., Santhosh, N., Ravichandran, G., Manjunath, N. (2020). Optimization of Friction Stir Welding Parameters Using Taguchi Method for Aerospace Applications. In: Vinyas, M., Loja, A., Reddy, K. (eds) Advances in Structures, Systems and Materials. Lecture Notes on Multidisciplinary Industrial Engineering. Springer, Singapore. https://doi.org/10.1007/978-981-15-3254-2_27\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Kevlar Fibre, PHA, FDM, Tensile properties, Flexural properties, Impact properties, Taguchi’s Design of Experiments","lastPublishedDoi":"10.21203/rs.3.rs-8702939/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8702939/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe paper is a scientific exploration of the optimization of the mechanical characteristics of biodegradable polyhydroxyalkanoates (PHA) reinforced with Kevlar fiber (KF) fabricated through Fused Deposition Modeling (FDM). Composite filaments with different weight fractions of 0 wt.%, 10 wt.% and 20 wt.% Kevlar fiber were processed and printed at different printing speeds (40 mm/s, 60 mm/s, and 80 mm/s), infill densities (60%, 80% and 100%), and build orientations ( 0 \u003csup\u003eo\u003c/sup\u003e, 45 \u003csup\u003eo\u003c/sup\u003e and 90 \u003csup\u003eo\u003c/sup\u003e ). The Taguchi L27 orthogonal array was applied in order to optimize the process parameters in terms of tensile, flexural, and impact properties on the basis of the larger-is-better signal-to-noise (S/N) ratio criterion. The experimental data showed that the ultimate tensile strength was at its highest of about 104 MPa \u0026ndash; 105 MPa, flexural strength of up to 97.7 MPa and impact energy of up to 2.25 J at the maximum infill density of 100% and 20 wt. % material content of Kevlar fibers. In case of tensile and flexural strength, the infill density was the most significant factor, and the delta value of the mean response analysis was highest, and Kevlar fiber content was the dominant factor in the optimization of impact strength. There were high synergies between the infill density and Kevlar fiber content as indicated by interaction plots. The similarity between the measured optimal conditions and the experimental ones proves the usefulness of Taguchi optimization in the improvement of the mechanical behavior of FDM-printed PHA\u0026ndash;Kevlar fiber composites in terms of lightweight structural applications.\u003c/p\u003e","manuscriptTitle":"Parametric Optimization of the Mechanical Characteristics of 3D Printed Kevlar Fibre ‑PHA Composites using Taguchi’s Design of Experiments","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-29 00:52:56","doi":"10.21203/rs.3.rs-8702939/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3fa1486a-d7a1-4976-bf6e-7ff29df9a356","owner":[],"postedDate":"January 29th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":61775292,"name":"Mechanical Engineering"},{"id":61775293,"name":"Materials Engineering"}],"tags":[],"updatedAt":"2026-01-29T00:52:56+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-29 00:52:56","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8702939","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8702939","identity":"rs-8702939","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}