{"paper_id":"0663dd14-e293-4d5c-8e53-104ec7b63cce","body_text":"An Analytical Model Experimentally Validated for Density Prediction in Arburg Plastic Freeforming | 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 An Analytical Model Experimentally Validated for Density Prediction in Arburg Plastic Freeforming Rita Porcaro, Giampaolo Campana, Maurizio Fiorini This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8980735/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 Arburg Plastic Freeforming combines pellet-based feedstock with droplet-wise deposition, offering material flexibility while posing challenges for achieving full-density repeatability at high printing speeds. An analytical model for part density prediction is proposed here. It is based on process velocity, derived from mass conservation and a tangential droplet-placement assumption, with geometric relationships expressed in terms of the Drop Aspect Ratio and layer thickness. A first campaign on polycarbonate droplet chains enabled us to quantify the deviation between the slicer pixel geometry and the real droplet morphology, thereby identifying a stable parameter set for use in the second experimental activity. Cubic specimens (10×10×10 mm³ ) were printed by varying the tangential speed from 0.05x to 6x, showing close agreement between the extruded and deposited volumes. Density measurements follow the predicted trend where deposition conditions are stable. However, variability in shutter oscillation frequency during high-speed printing alters droplet spacing and undermines consistent full density. Accounting for the measured frequency or propagating its uncertainty within the model restores predictive accuracy and provides practical guidance for process setup and monitoring. The proposed framework reduces trial-and-error and supports future closed-loop strategies to stabilise frequency-velocity coupling, improving reproducibility and enabling wider industrial adoption of Arburg Plastic Freeforming. Additive Manufacturing Arburg Plastic Freeforming Part Density Polycarbonate Process Modelling 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-8980735\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":602447326,\"identity\":\"ad16044c-7540-4d8d-8545-0f7dfaa23328\",\"order_by\":0,\"name\":\"Rita Porcaro\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4UlEQVRIiWNgGAWjYDACZmTOhwoGBjYJICMBrxYkPYwzzsC04NeDxORtA5IgLfisMW/nP/iBcYdNPn/72YcPeOcdzuOTbj7A8PAHbi0yh5mZJRjPpFnOOJNubCC57XAxm8yxBLwOkwD6RYKx7bCBAUMam4ThtsOJbRI5BoS0MP8Aa+F/xiaROIc4LWwQWySAthxsIE6LmUXimTQDiRvPmA0bjqUntgH9ciAhDY8W/oOPb3zcYWPA35/G+PhPjXXi/NnNBx/+sMGtBQwSG9AEDhDQAIx1dC2jYBSMglEwCpABAFY3SGhHLf1sAAAAAElFTkSuQmCC\",\"orcid\":\"\",\"institution\":\"University of Bologna\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Rita\",\"middleName\":\"\",\"lastName\":\"Porcaro\",\"suffix\":\"\"},{\"id\":602447327,\"identity\":\"fe5e801a-1086-48ab-941c-74fd7a10b843\",\"order_by\":1,\"name\":\"Giampaolo Campana\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"University of Bologna\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Giampaolo\",\"middleName\":\"\",\"lastName\":\"Campana\",\"suffix\":\"\"},{\"id\":602447328,\"identity\":\"ad9f2fd5-21d6-44bb-95f9-b0bfe93a3ade\",\"order_by\":2,\"name\":\"Maurizio Fiorini\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"University of Bologna\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Maurizio\",\"middleName\":\"\",\"lastName\":\"Fiorini\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2026-02-26 18:24:25\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-8980735/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-8980735/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":104779690,\"identity\":\"3e950d05-a88f-44a5-8136-e71bf24d7f5a\",\"added_by\":\"auto\",\"created_at\":\"2026-03-17 07:44:42\",\"extension\":\"pdf\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":704963,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"ManuscriptA.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-8980735/v1_covered_247889f2-85e1-452f-ba9b-992597460fdd.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"An Analytical Model Experimentally Validated for Density Prediction in Arburg Plastic Freeforming\",\"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\":\"info@researchsquare.com\",\"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, Arburg Plastic Freeforming, Part Density, Polycarbonate, Process Modelling\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-8980735/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-8980735/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eArburg Plastic Freeforming combines pellet-based feedstock with droplet-wise deposition, offering material flexibility while posing challenges for achieving full-density repeatability at high printing speeds. An analytical model for part density prediction is proposed here. It is based on process velocity, derived from mass conservation and a tangential droplet-placement assumption, with geometric relationships expressed in terms of the Drop Aspect Ratio and layer thickness.\\u003c/p\\u003e \\u003cp\\u003eA first campaign on polycarbonate droplet chains enabled us to quantify the deviation between the slicer pixel geometry and the real droplet morphology, thereby identifying a stable parameter set for use in the second experimental activity. Cubic specimens (10\\u0026times;10\\u0026times;10 \\u003cem\\u003emm\\u0026sup3;\\u003c/em\\u003e) were printed by varying the tangential speed from 0.05x to 6x, showing close agreement between the extruded and deposited volumes.\\u003c/p\\u003e \\u003cp\\u003eDensity measurements follow the predicted trend where deposition conditions are stable. 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