(777a) Tailored Polymers for Structural Application in Large-Scale Extrusion Systems

The explosive growth of inexpensive polymer-based 3D printers across the economy has been driven in part by the promise of true freeform production coupled to digital design. However - as anyone with experience in 3D printing will attest - the hype surrounding the set of technologies known as additive manufacturing often precludes the significant shortcomings and trade-offs inherent in currently available products. In order to realize the full potential of 3d printed products, significant issues in polymer material systems must be addressed.

Material defects are often introduced in 3d printers due to process variability, complex thermal histories due to variable part geometries, sub-optimal toolpaths, process artifacts from machines and software, interfacial chemical reactions between layers and reinforcements, operator errors, and a variety of other variables. Additionally, the set of polymers available for 3D printing is further constrained by practical considerations such as rheology, shelf-life, environmental stability, commercial availability, and cost. These challenges are primarily addressed through either process modification or material system development.

This talk will focus primarily on polymer system development for very large-scale (100 pounds per hour deposition up to about 1000 cubic feet build volume) but will also highlight examples where process and material development are highly dependent on one another. Topics covered will include desired material properties for printing, the role of composite reinforcement materials, composite reinforcement interface and surface chemistry, advanced magnetic multifunctional composite systems, a survey of material systems under development, and highlights of results from recent R&D. Results and highlights will focus on work performed via public-private partnership by the Manufacturing Demonstration Facility (MDF) at Oak Ridge National Laboratory with support from the Advanced Manufacturing Office at the U.S. Department of Energy.