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Anastasios John Hart. Daguilh, Thad. Massachusetts Institute of Technology. Department of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering 2019-12-13T18:58:12Z 2019-12-13T18:58:12Z 2019 2019 https://hdl.handle.net/1721.1/123262 1130061543 Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2019 Cataloged from PDF version of thesis. Includes bibliographical references (page 31). Extrusion-based additive manufacturing, known as fused filament fabrication (FFF), is one the most accessible methods of rapid prototyping, capable of handling a wide variety of engineering thermoplastics. Productivity limitations hinder the further application of FFF to both prototyping and production. An FFF system consists of three synchronized processes: heat conduction into the feedstock, gantry speed, and extrusion of the feedstock by a pinch wheel mechanism. Each one of these processes can become a rate-limiting factor for prints. This work explores resistive joule heating as a method to increase heat transfer into an electrically conductive composite feedstock. This requires usage of an electrically insulating liquefier in order to co-locate both conduction and joule heating. A prototype mechanism was designed and fabricated including an anodized aluminum liquefier capable of printing. This was tested and no significant difference in print times were noted because of a failure in the system due to a current jump around the joule heating section. Although physical tests were not a success, a LabVIEW VI was created for future testing. In addition, modeling was performed to conclude that a 2.85mm PLA filament would be used in the range of 80-100V and 0.2-0.25A with a joule heating length of 0.75cm in the system in order to reach an extrusion rate of 200 cm³ /hr. by Thad Daguilh. S.B. S.B. Massachusetts Institute of Technology, Department of Mechanical Engineering 31 pages eng Massachusetts Institute of Technology MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. http://dspace.mit.edu/handle/1721.1/7582 Mechanical Engineering. A joule heating mechanism for high-speed fused filament fabrication Thesis application/pdf 2019-12-13T18:58:12Z Publication Bachelor MechE unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="fba8a738-5c3b-4da0-aca1-8a872eda90f0"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>A joule heating mechanism for high-speed fused filament fabrication</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2019</PublicationDate> <Authors> <Author> <DisplayName>Daguilh, Thad.</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Mechanical Engineering.</Keyword> <Abstract>Extrusion-based additive manufacturing, known as fused filament fabrication (FFF), is one the most accessible methods of rapid prototyping, capable of handling a wide variety of engineering thermoplastics. Productivity limitations hinder the further application of FFF to both prototyping and production. An FFF system consists of three synchronized processes: heat conduction into the feedstock, gantry speed, and extrusion of the feedstock by a pinch wheel mechanism. Each one of these processes can become a rate-limiting factor for prints. This work explores resistive joule heating as a method to increase heat transfer into an electrically conductive composite feedstock. This requires usage of an electrically insulating liquefier in order to co-locate both conduction and joule heating. A prototype mechanism was designed and fabricated including an anodized aluminum liquefier capable of printing. This was tested and no significant difference in print times were noted because of a failure in the system due to a current jump around the joule heating section. Although physical tests were not a success, a LabVIEW VI was created for future testing. In addition, modeling was performed to conclude that a 2.85mm PLA filament would be used in the range of 80-100V and 0.2-0.25A with a joule heating length of 0.75cm in the system in order to reach an extrusion rate of 200 cm³ /hr.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>