Investigation of Shape Memory Recovery in Thermally Activated PLA-TPU Blends Using Fused Granular Fabrication (FGF)

Investigation of Shape Memory Recovery in Thermally Activated PLA-TPU Blends Using Fused Granular Fabrication (FGF) | 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 Shape Memory Recovery in Thermally Activated PLA-TPU Blends Using Fused Granular Fabrication (FGF) Deepak Haresh Devjani, Wael Abdel Samad, Salman Pervaiz This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7348961/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 16 Dec, 2025 Read the published version in Progress in Additive Manufacturing → Version 1 posted You are reading this latest preprint version Abstract The current paper presents a study on the shape memory effect (SME) on thermally activated PLA-TPU polymer blends that have been produced using the emerging additive manufacturing technique of Fused Granular Fabrication (FGF) as a new pellet-based technique. The melt mixing and pelletization processes were conducted to prepare three ratios of blend (90:10, 80:20, 70:30 PLA: TPU), and then 3D printed as cubic specimens with different infill patterns (honeycomb, triangular and grid) and density (10%, 25%, 40%). The specimens were mechanically programmed under three levels of compressive strain (10%, 25%, 40%), then activated in hot water. The peak compressive strength (PCS) was measured alongside shape fixity ratio (Rf), recovery ratio (Rr) and overall SME. To analyze the effect of the four inputs in a systematic way, a Taguchi L27 orthogonal array was used to analyze the results, followed by statistical analysis using ANOVA and Grey Relational Analysis (GRA). It was found that the compression ratio produced the largest impact on shape restoration (70.71% impact) and the infill density and pattern only impacted heavily on the mechanical compressive strength. The optimum combination comprised of 30% TPU, 40% infill density, honeycomb-pattern combined with 25 to 40% compression that had SME values of over 75% and showed improved fidelity of recovery. These results support the idea regarding the use of PLA-TPU blends in the use of 4D printing of programmable structures and smart materials, particularly in those applications that require compressive deformation and thermal recovery. Fused Granular Fabrication (FGF) PLA-TPU Blend Shape Memory Effect 4D Printing Pellet-Based Additive Manufacturing Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 16 Dec, 2025 Read the published version in Progress in Additive Manufacturing → 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. 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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-7348961","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":504632121,"identity":"e5cfe149-ac9c-49a0-b989-6333cf8c5e0b","order_by":0,"name":"Deepak Haresh Devjani","email":"","orcid":"","institution":"Rochester Institute of Technology - Dubai","correspondingAuthor":false,"prefix":"","firstName":"Deepak","middleName":"Haresh","lastName":"Devjani","suffix":""},{"id":504632122,"identity":"f86f77c1-02d2-4d45-9716-7322689f03d4","order_by":1,"name":"Wael Abdel Samad","email":"","orcid":"","institution":"Rochester Institute of Technology - Dubai","correspondingAuthor":false,"prefix":"","firstName":"Wael","middleName":"Abdel","lastName":"Samad","suffix":""},{"id":504632123,"identity":"5a6ba241-66ae-41f1-bd35-d0edaa9dbffe","order_by":2,"name":"Salman Pervaiz","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAq0lEQVRIiWNgGAWjYNACNhsGNhDNQ4KWNAY2NhK1HGZgIFqL/Izcgx9+lJ3P55NvYHzwto0ILQZnziVL9py7bdnGxsBsOJcoLew9Zgy8bbcNgH5hk+YlRot8M48Z49+2cyAt7L+J0sJwvMeMmbftANgWZqK0gPwiLXMuGaglsVlyzjliHAYMsY9vyuwM5JsPH/zwpowYhyHigrGBKPUMJMX4KBgFo2AUjFAAAAaWLNEoi5KIAAAAAElFTkSuQmCC","orcid":"","institution":"Rochester Institute of Technology - Dubai","correspondingAuthor":true,"prefix":"","firstName":"Salman","middleName":"","lastName":"Pervaiz","suffix":""}],"badges":[],"createdAt":"2025-08-11 18:23:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7348961/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7348961/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s40964-025-01458-x","type":"published","date":"2025-12-16T15:58:33+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":98814238,"identity":"ef85f553-eba0-4e97-ab4a-06dcbb86c589","added_by":"auto","created_at":"2025-12-22 16:12:00","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1398284,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7348961/v1_covered_3434ac6a-ba1f-4233-81d3-736238e1e95c.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Investigation of Shape Memory Recovery in Thermally Activated PLA-TPU Blends Using Fused Granular Fabrication (FGF)","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"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":"Fused Granular Fabrication (FGF), PLA-TPU Blend, Shape Memory Effect, 4D Printing, Pellet-Based Additive Manufacturing","lastPublishedDoi":"10.21203/rs.3.rs-7348961/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7348961/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe current paper presents a study on the shape memory effect (SME) on thermally activated PLA-TPU polymer blends that have been produced using the emerging additive manufacturing technique of Fused Granular Fabrication (FGF) as a new pellet-based technique. The melt mixing and pelletization processes were conducted to prepare three ratios of blend (90:10, 80:20, 70:30 PLA: TPU), and then 3D printed as cubic specimens with different infill patterns (honeycomb, triangular and grid) and density (10%, 25%, 40%). The specimens were mechanically programmed under three levels of compressive strain (10%, 25%, 40%), then activated in hot water. The peak compressive strength (PCS) was measured alongside shape fixity ratio (Rf), recovery ratio (Rr) and overall SME. To analyze the effect of the four inputs in a systematic way, a Taguchi L27 orthogonal array was used to analyze the results, followed by statistical analysis using ANOVA and Grey Relational Analysis (GRA). It was found that the compression ratio produced the largest impact on shape restoration (70.71% impact) and the infill density and pattern only impacted heavily on the mechanical compressive strength. The optimum combination comprised of 30% TPU, 40% infill density, honeycomb-pattern combined with 25 to 40% compression that had SME values of over 75% and showed improved fidelity of recovery. These results support the idea regarding the use of PLA-TPU blends in the use of 4D printing of programmable structures and smart materials, particularly in those applications that require compressive deformation and thermal recovery.\u003c/p\u003e","manuscriptTitle":"Investigation of Shape Memory Recovery in Thermally Activated PLA-TPU Blends Using Fused Granular Fabrication (FGF)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-26 09:10:30","doi":"10.21203/rs.3.rs-7348961/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":"0dfe7ee3-4437-429e-9934-dd0d2c97ac1c","owner":[],"postedDate":"August 26th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-22T16:06:46+00:00","versionOfRecord":{"articleIdentity":"rs-7348961","link":"https://doi.org/10.1007/s40964-025-01458-x","journal":{"identity":"progress-in-additive-manufacturing","isVorOnly":false,"title":"Progress in Additive Manufacturing"},"publishedOn":"2025-12-16 15:58:33","publishedOnDateReadable":"December 16th, 2025"},"versionCreatedAt":"2025-08-26 09:10:30","video":"","vorDoi":"10.1007/s40964-025-01458-x","vorDoiUrl":"https://doi.org/10.1007/s40964-025-01458-x","workflowStages":[]},"version":"v1","identity":"rs-7348961","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7348961","identity":"rs-7348961","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}