A joule heating mechanism for high-speed fused filament fabrication

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.

Name thesis:degree_name

Bachelor

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2019

Author dc:creator

• Daguilh, Thad.

Advisor dc:contributor.advisor

• Anastasios John Hart.

• Mechanical Engineering.

Statement dc:rights

• 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.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/123262

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/123262