The Problem:
Large-scale additive manufacturing (AM) of thermoset polymer composites requires mixing of fiber-containing components at the point of deposition. Traditional baffle-type passive mixers significantly increase the energy and pressure required to pump material while also limiting the fiber content in the deposited material. Passive-type mixers are also prone to clogging with fiber-containing materials, which can lead to significant down-time. Dynamic mixers that utilize impellers are more compact but may significantly reduce fiber length during the mixing process, which, in turn, reduces performance of the printed composite.
The Solution:
Researchers at the University of Tennessee have developed an inline dynamic mixer that allows 3D printing of fiber-containing polymers without the problems associated with existing passive and dynamic mixers. This new dynamic mixer design efficiently mixes materials without impellers or blades, reducing fiber length attrition during deposition and enabling the utilization of higher fiber loading to achieve printed composite materials with superior mechanical properties.
Benefits:
The Inventor:
Dr. Brett Compton is an assistant professor in the Department of Mechanical Aerospace, and Biomedical Engineering at UT. He received his Ph.D. in materials science from the University of California, Santa Barbara in 2012. Dr. Compton then studied as a postdoctoral research fellow at Harvard University and worked at Oak Ridge National Laboratory before joining UT in 2015. His research interests include mechanical properties of advanced composite materials, developing high-performance materials for additive manufacturing, and understanding the fundamental processing-property-performance relationships in additive manufacturing materials.
He has particular expertise in 3D-printable thermoset-based composite materials.