Direct Joining of Recycled Polypropylene Composites with Aluminum via Screw Extrusion-Based Additive Manufacturing Toward Three-Dimensional Polymer–Metal Hybrids

Direct Joining of Recycled Polypropylene Composites with Aluminum via Screw Extrusion-Based Additive Manufacturing Toward Three-Dimensional Polymer–Metal Hybrids | 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 Direct Joining of Recycled Polypropylene Composites with Aluminum via Screw Extrusion-Based Additive Manufacturing Toward Three-Dimensional Polymer–Metal Hybrids Hyunsub Yoon, Wook-Bae Kim This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7309387/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 This study investigates the influence of nanosecond laser ablation micropatterns on aluminum surfaces for direct joining strength in polymer-metal hybrids fabricated using extrusion-based additive manufacturing of recycled polypropylene (rPP) composites. While integration of polymer extrusion-based processes with direct joining represents a highly efficient production approach, achieving both joining strength comparable to conventional methods and dimensional stability remains challenging. Contrary to reported poor joining characteristics of virgin polypropylene, rPP demonstrated effective joining when aluminum surfaces were heated above the crystallization temperature. Glass fiber-reinforced rPP exhibited minimized shrinkage and warping, enabling continuous building processes following initial joining. Single lap shear testing across two materials and three laser micropattern configurations on Al6061 substrates revealed that micro-groove patterns parallel to nozzle path direction provide optimal joining performance. Statistical analysis confirmed significant effects of both material type and surface patterns on failure loads. Maximum failure loads of 2080 N were achieved over 10×13.2 mm² joining areas, enabling fabrication of box-shaped polymer-metal hybrids with minimal warping. This integrated manufacturing approach offers efficient application potential for lightweight multi-material component fabrication based on recycled materials and environmentally sustainable processes. Additive manufacturing Direct joining Laser micropatterning Polymer-metal hybrid Recycled polypropylene 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. 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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-7309387","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":503731810,"identity":"458df599-2a65-43bb-8041-ef6ba219e13d","order_by":0,"name":"Hyunsub Yoon","email":"","orcid":"","institution":"Tech University of Korea","correspondingAuthor":false,"prefix":"","firstName":"Hyunsub","middleName":"","lastName":"Yoon","suffix":""},{"id":503731811,"identity":"d04956fd-0d72-427b-bff7-9f998baa37fe","order_by":1,"name":"Wook-Bae Kim","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxklEQVRIiWNgGAWjYDACHsYGhg8MDAZwAQlitDDOSCBNCwMDMw9JWgzOHG7dbPvjsDG/9OGDHxhq7BgkZx8goOVsY9vtnITDZpJ9ackSDMeSGaT5EvBrMTvPCNZiY3CGx0CCge0AgxwPAYeBtViAtfB//sHwjxgtIIcxAB0GtIVNgrHtAIM0IS32Zw623exJSzeW7GEzs0jsS+aR7CGgRbIn/dmNHzbWhv08zI9vfPhmJydxhoAWVJAAjqdRMApGwSgYBRQDADUJPmuO3qw7AAAAAElFTkSuQmCC","orcid":"","institution":"Tech University of Korea","correspondingAuthor":true,"prefix":"","firstName":"Wook-Bae","middleName":"","lastName":"Kim","suffix":""}],"badges":[],"createdAt":"2025-08-06 11:38:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7309387/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7309387/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":92342539,"identity":"c250201f-3301-42e0-907b-3f0b95a37d6b","added_by":"auto","created_at":"2025-09-28 07:31:56","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1715522,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript250806DirectjoiningofrPPcomposite.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7309387/v1_covered_fd64de21-4165-4d1f-9fdd-f8b85f7027a9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Direct Joining of Recycled Polypropylene Composites with Aluminum via Screw Extrusion-Based Additive Manufacturing Toward Three-Dimensional Polymer–Metal Hybrids","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":"Additive manufacturing, Direct joining, Laser micropatterning, Polymer-metal hybrid, Recycled polypropylene","lastPublishedDoi":"10.21203/rs.3.rs-7309387/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7309387/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study investigates the influence of nanosecond laser ablation micropatterns on aluminum surfaces for direct joining strength in polymer-metal hybrids fabricated using extrusion-based additive manufacturing of recycled polypropylene (rPP) composites. 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