This paper discusses a novel additive manufacturing technique that was developed in order to 3D print polymeric parts with tunable properties. This technique, known as 4D-Rheoprinting, can be applied to a number of common additive manufacturing processes including any extrusion or fused deposition based system. The applied processing shear rate can be tuned precisely within each printing road or strand to proactively control the resulting localized molecular orientation and/or crystallinity level in the final product. Molecular orientation and crystallinity in turn have enormous impacts on mechanical, thermal and biodegradation properties of polymeric parts. Since additive manufacturing parts are built using layers from the ground up, we can build one product with different core and surface properties by controlling molecular orientation of each strand which significantly broadens the range of potential 3D printing applications. The current alternative approaches to customize 3D printed parts are to optimize infill, add different material and perform post processing steps such as annealing or treating with chemicals. Our technique of tuning shear rate to affect molecular orientation and crystallinity could be combined with infill optimization for maximum performance in wide range of applications. In this investigation a polymer strand is printed using the RheoPrinting technique. DSC and XRD are preformed and the results of the samples printed using this technique are compared to the samples that were printed using conventional extrusion based 3D printers.
Journal: TechConnect Briefs
Volume: 4, Informatics, Electronics and Microsystems: TechConnect Briefs 2018
Published: May 13, 2018
Pages: 87 - 91
Industry sector: Advanced Materials & Manufacturing
Topics: 3D Printing