Low Cost Mold Development for Prototype Parts Produced by Vacuum Assisted Resin Transfer Molding (VARTM)

ABSTRACT: A low cost prototype mold, used in the vacuum assisted resin transfer molding (VARTM) process, was developed and manufactured using inexpensive materials and tooling methods. Several available mold materials were investigated from Polytetrafluoroethylene (PTFE) and aluminum to less conventional materials such as ultra high molecular weight polyethylene and oak. Through a multiple generation approach, a fully functional mold was developed capable of producing parts of accurate and reproducible dimensions. The use of conventional machine shops over fully automated machine shops was utilized for additional savings. Race tracking is a common problem in the VARTM process. A two-part room temperature vulcanizing rubber was used to seal the ends of the fibers and act as a mold gasket for vacuum. These baffles, created by sealing the fiber ends to the mold, forced the resin through the fibers and eliminated the race-tracking problem. KEY WORDS: vacuum assisted resin transfer molding, race tracking, composite materials, fiber reinforced polymers, mold development