Bubble free resin for infusion process

The vacuum infusion process has been found to be very versatile for making large composite structures. During the resin impregnation process, the vacuum causes the nucleation and formation of air bubbles from gasses dissolved in the resin. One solution to this would be a degassing process prior to infusion. Recent experiments have shown that a degassing process, conducted in batches with a small quantity of a bubble nucleation agent (Scotch-Brite) and an air sparging method could reduce void formation in the vacuum infusion process. At 90 mbar, this method of degassing may remove 40-50% of the dissolved gas. However, despite reducing the level of dissolved gas, some micro-bubbles remain suspended due to the viscosity of the resin and contribute to void formation. While these results were quite encouraging, there is a need to design a system to ensure a continuous supply of degassed resin as a better way forward. In a continuous degassing system, it is necessary to establish the relationship between the degassing process quality and void content reduction from the perspective of strength and performance, besides signifying the most viable method of degassing.