Fabrication and Characterization of Polymer Composites with the Help of an Enhanced Vacuum Moulding Technique

Composite fabrication is widely undertaken by VARTM approach with an aim to enhance productivity. However, the pace of resin front, method of degassing of the resin-hardener mix decide the level of trapped gases and air bubbles in the resin flow. This eventually leads to degraded characteristics of the cured composite. The study proposes an improvement in the traditional vacuum bagging process such that there is a significant improvement in the tensile and flexural strength up to 20%. Entrapped bubbles are one of the major drivers of Porosity defect which the current study has attempted to overcome. Degassing time and vacuum pump condition are found to control the vacuum bagging process. Five experiments are performed with three degassing conditions (i.e., no degas, 5 min of degas, and 10 min of degas) and two vacuum pump conditions while infusing the resin. Flexural characterization was performed to identify the optimum process parameters during the vacuum bagging process. ASTM D7264 is used to conduct the 3-point bend test on the composite samples, made of Epoxy 1564 and Aradur 22962, reinforced with 200 gsm plain glass weave fabric. It is found that a degassing time of 5 min and vacuum pump turned off during resin infusion produced the best results.