Vacuum infusion is a type of closed mould composite fabrication method.  Epoxy resin is introduced into the mould after the vacuum has pulled the bag down and compacted the laminate.

The reinforcements and core material are laid-up dry in the mould. This is done by hand and provides the opportunity to precisely position the reinforcement. When the resin is pulled into the Mould the laminate is already compacted; therefore, there is no room for excess resin. Very high resin to glass ratios are possible with vacuum infusion and the mechanical properties of the laminate are superior.

Based on curing temperature and Tg, CA Composites supplies two categories of vacuum infusion epoxy resin.