Introduction to low-cost manufacturing of polymeric composites

Composites are popular in high performance applications owing to their high specific strength characteristic and an endurance limit greater than that of traditional structural materials such as steel and aluminum. The paper discusses an experiment designed for students to be exposed to the low-cost manufacturing of high performance composites. The experiment is designed for a junior level manufacturing processes laboratory. In this experiment, students use the Vacuum Assisted Resin Infusion Molding process (VARIM) to fabricate woven polymeric composite panels. A mold is loaded with the preform made of the reinforcement material. The mold is then closed and resin is injected into it, aided by a vacuum pressure at the vents to remove all the entrapped air in the preform and speed up the process. Resin flows in the plane as well as in the transverse direction of the preform. Students evaluate the quality of their work by testing tensile coupons cut out of those panels. Four groups of up to five students work on producing four panels. Twenty tensile coupons are cut from each panel, and coupon tests enable students to compare spatial variation of properties within a given panel caused by the manufacturing process. In addition to the experience in processing, measuring, and statistical analysis, students become aware of cost considerations in manufacturing, since they are required to track materials and labor costs during the experiment.