Investigation of the influence of resin coating and heat treatment on the mechanical properties of topology-optimized parts made of polylactic acid (PLA) by the fused filament fabrication (FFF)

Investigation of the influence of resin coating and heat treatment on the mechanical properties of topology-optimized parts made of polylactic acid (PLA) by the fused filament fabrication (FFF) | 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 Investigation of the influence of resin coating and heat treatment on the mechanical properties of topology-optimized parts made of polylactic acid (PLA) by the fused filament fabrication (FFF) Ali Jadali, Vahid Abedini, Abdolvahed Kami This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8917297/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 Fused filament fabrication (FFF) allows the manufacturing of complex and lightweight polymer components; yet, the mechanical performance of topology-optimized parts is constrained by interlayer weaknesses, residual stresses, and diminished crystallinity. This study systematically investigates the combined effects of heat treatment and resin coating on the compressive behavior of topology-optimized polylactic acid (PLA+) structures produced by FFF. Topology optimization was conducted utilizing the Solid Isotropic Material with Penalization (SIMP) approach to attain a specified mass reduction of 60% while maintaining structural stiffness. The optimized geometry was manufactured and later subjected to post-processing at various heat-treatment temperatures and durations, both with and without resin coating. A central composite design (CCD) inside a response surface methodology (RSM) framework was utilized to assess the individual and interaction effects of post-processing parameters on the maximum compressive load (MCL). Statistical investigation indicated that heat-treatment duration is the most significant variable, succeeded by temperature and coating condition. An ideal post-processing conditions around 82 °C for 90 minutes with resin coating provided a ~34% increase in MCL relative to the as-printed topology-optimized specimen. X-ray diffraction analysis verified a significant increase in crystallinity (≈232%), explaining the noted mechanical enhancement, whereas FESEM analysis indicated a consistent, defect-free coating layer with robust interfacial adhesion. The suggested combined optimization and post-processing strategy provides an efficient method for manufacturing lightweight PLA components with significantly enhanced load-bearing capacity for engineering applications. Topology optimization Fused filament fabrication (FFF) Polylactic acid (PLA) Heat treatment Resin coating Full Text Additional Declarations No competing interests reported. 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. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8917297","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":599918361,"identity":"bb8ee03f-b58d-4ae0-b9ed-02c3b9d4b490","order_by":0,"name":"Ali Jadali","email":"","orcid":"","institution":"Semnan University","correspondingAuthor":false,"prefix":"","firstName":"Ali","middleName":"","lastName":"Jadali","suffix":""},{"id":599918363,"identity":"184f374d-7654-440f-95fb-a48af87193e7","order_by":1,"name":"Vahid Abedini","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5UlEQVRIiWNgGAWjYHACNiCSYGBjb0ASSyBKC88B0rQAKQkCyuDA4ADzswcfyizy+CSfP3x0c4ddHgP74QcMD/fg08JmbjjjnEQxm3SOsXHumeRiBp40A4aEZ7i1SDYwmEnztkkktknnsEnntjEnNjDkAP1yAJ8W9m/Sf0FaJI8//53bVp/YwP8GvxZ+Bh4zaUaQFgkGM+bctsOJDRIEbOFn5ik37DkH1MKTYwx02HGg3mcGB/BpYWNv3/bgR1ld4vz24w8/57ZVJ/bzJz98+AOPFgZmDEOAGJ+GUTAKRsEoGAVEAADkz0mGywr/KgAAAABJRU5ErkJggg==","orcid":"","institution":"Semnan University","correspondingAuthor":true,"prefix":"","firstName":"Vahid","middleName":"","lastName":"Abedini","suffix":""},{"id":599918364,"identity":"f34f2a82-8f42-4a2d-8476-8fe816b1bb3e","order_by":2,"name":"Abdolvahed Kami","email":"","orcid":"","institution":"Semnan University","correspondingAuthor":false,"prefix":"","firstName":"Abdolvahed","middleName":"","lastName":"Kami","suffix":""}],"badges":[],"createdAt":"2026-02-19 11:53:58","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8917297/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8917297/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104808289,"identity":"883fd5b7-008a-4f60-977c-7ede05f7b764","added_by":"auto","created_at":"2026-03-17 12:35:26","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2107297,"visible":true,"origin":"","legend":"","description":"","filename":"PLATORCHTENManuscriptV1.114041002.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8917297/v1_covered_dc540e41-b6d6-4ab0-9f8f-5da8626215b9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Investigation of the influence of resin coating and heat treatment on the mechanical properties of topology-optimized parts made of polylactic acid (PLA) by the fused filament fabrication (FFF)","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"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":"Topology optimization, Fused filament fabrication (FFF), Polylactic acid (PLA), Heat treatment, Resin coating","lastPublishedDoi":"10.21203/rs.3.rs-8917297/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8917297/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Fused filament fabrication (FFF) allows the manufacturing of complex and lightweight polymer components; yet, the mechanical performance of topology-optimized parts is constrained by interlayer weaknesses, residual stresses, and diminished crystallinity. 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An ideal post-processing conditions around 82 °C for 90 minutes with resin coating provided a ~34% increase in MCL relative to the as-printed topology-optimized specimen. X-ray diffraction analysis verified a significant increase in crystallinity (≈232%), explaining the noted mechanical enhancement, whereas FESEM analysis indicated a consistent, defect-free coating layer with robust interfacial adhesion. 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