In the filed of composites, resin infusion is a process where the voids in an evacuated stack of porous material are filled with a liquid resin. When the resin solidifies, the solid resin matrix binds the assembly of materials into a unified rigid composite. The resinforcement can be any porous material compatible with the resin. Typical materials are inorganic fibres (with glass fibers being most common), organic fibres such as flax, or combinations of fibres with other materials such as closed cell foams, balsawood, and honeycomb. Porous materials can also be infused onto the surfaces of non-porous materials such as sheet metal. Resins are usually thermosetting types.
A key part of the process is the evacuation, or removal, of the air from the porous material prior to admitting the resin. The air needs to be removed from the porous material to allow the resin to take its place. In its simplest form the process can be broken down into the following stages.
Why use the infusion process?
The resin infusion process is a cost effective method of manufacturing high quality and high strength composite parts that are required in relatively low quantities, say less than a few hundred identical pieces per mould per year, or physically large parts which are difficult, or prohibitively expensive to make by any other method.