Resin infusion is a specific form of resin transfer molding (RTM). Alternate names include vacuum infusion process (VIP) and vacuum assisted RTM (VARTM).

There is no injection pressure associated with the resin infusion process. The system is not directly connected to the mold; rather, the system fills a bucket or drum with catalyzed resin. The mold has a vacuum applied to it and a supply line that runs from the mold into the bucket or drum of mixed material. The vacuum source draws the material from the container into the mold.

Infusion can be accomplished with low viscosity resins such as polyester, epoxy and urethane. The type of chemistry and flow rates will dictate the type of meter mix or resin handling equipment that is required.