Impregnation molding is a method to shape objects using resins, in which liquid resins are impregnated into materials with holes and then hardened. The materials include carbon fibers, micas, metals, wood and ceramics, depending on the use. According to the type of resin, the method often employs a heat-hardening resin (thermosetting resin).
Airtightness and intensity of the materials can be increased by impregnating them with resins. Fiber reinforced plastics, which have resins impregnated into carbon fibers or glass fibers, have intensities as strong as metals but are lighter than metals. Accordingly, they are used for vehicle bodies, aircraft fuselages and wind turbine propellers, among other applications. Moreover, as resins themselves have high electrical insulating properties, materials such as micas that are impregnated with resins are used as insulation materials for electrical products.
The molding techniques include a method where materials are dipped in resins and a method where resins are poured into molds in which carbon fibers or glass fibers are placed. The pace at which the resins infiltrate and the time required for the resins to harden differ depending on the temperature, pressure and material structures. As such, it is generally difficult to accurately predict the time needed for molding.