Resin infusion

FRP construction using resin infusion

How resin infusion works

Resin infusion uses a vacuum to draw liquid resin into a dry fiber lay-up, producing repeatable composite parts while limiting volatile organic compound (VOC) emissions. The process is compatible with commonly used fiber reinforcements and resin systems. It is suited to large structural components that require strength, durability and low weight. Dry reinforcement, core materials and inserts are placed in a mold, covered with a vacuum bag and sealed. Resin enters through inlet ports and flows through distribution media and channels until the laminate is saturated. Vacuum pressure compacts the dry fibers. Karmin’s original process description gives a typical fiber content of 55–65% by weight, depending on the reinforcement, fiber architecture and resin system.

The vacuum removes air from the lay-up before and during infusion. The pressure difference between the atmosphere and the vacuum drives resin through the reinforcement.