ERI: Fused Filament Fabrication of Thermoplastic-Composite Molds Embedded with Heating Wires for Energy-Efficient Production of Thermoset Composites

University Of Houston - Clear Lake, Houston TX

Investigators

Abstract

High-performance polymer composites are attractive for many lightweight and reinforced-structure applications as an alternative to metallic parts. However, the associated cost with composite manufacturing, more specifically, the extensive cost of mold-making and mold heating do limit their large-scale production. The traditional autoclave heating of a mold requires tooling assembly and a relatively long lead time, which add up the manufacturing cost and pose significant challenges to widespread adoption. This Engineering Research Initiation (ERI) award supports fundamental research to understand additive manufacturing (AM) of thermoplastic-composite out-of-oven molds to make thermoset composites. The research effort will develop and integrate a lower-cost tool that enables the deposition of heating wires within parts made by fused filament fabrication (FFF), in the presence of a nonpolar solvent, to fabricate composite molds. If successful, such an innovation will eliminate the necessity of costly and energy-intensive autoclave ovens, serving as technological groundwork of composite manufacturing and enhance the U.S. composite tooling competitiveness in the global market. This ERI project will also engage a diverse group of students, including underrepresented minorities, in new manufacturing technologies and provide hands-on experiences to develop scientific, analytical thinking, and leadership skills. In addition, the team will partner with school districts in the gulf coast area of Houston for outreach activities that promote K-12 students to pursue a career in STEM-related fields. The overall goal of this research is to establish and understand a system for AM of resistance heating wire embedded out-of-oven composite molds made of short carbon-fiber reinforced polycarbonate. For embedding heating wires during 3D printing, the project will investigate the fundamentals of thermoplastic swelling due to nonpolar solvents by solid-state nuclear magnetic resonance and Fourier transform infrared spectroscopy. The study will build the basis for the development of a dual-extrusion FFF printer integrated with a resistance heating wire deposition system to produce composite molds for the investigation into the interaction between heating wires and thermoplastics. The effect of wire heating on the temperature profile of the fabricated mold will be characterized by infrared thermography and correlated with the mechanical evaluation of fabricated composite molds. In addition, thermoset composite components made by the heating-wire embedded molds and conventional autoclave molds will be quantitatively compared. The findings of this research are expected to generate new knowledge on material-extrusion based AM of embedded heating composite molds for energy-efficient composite manufacture. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.