A molding resin is a thermosetting plastic based on epoxy or polyurethane. Molding resins are usually two-component systems consisting of a resin (A) and a hardener (B). If required, a filler can be added as a third component. Molding resins are available in a variety of products, which differ in their mechanical properties (e.g. density, hardness, compressive strength, flexural strength), their chemical properties (viscosity, curing time, chemical resistance etc.), and processing properties (shrinkage behavior, pot life, mixing ratio etc.).
Molding resins are used in the manufacture of molds that are made by taking an impression of a master model. If the mold is produced using a casting process in which the master model is completely encapsulated with the molding resin, a casting system is used as the molding resin. If the mold is produced using the lay-up method, the molding resin is a so-called gelcoat resin, which can be backed up with other resin systems for stabilization after application.
One advantage of mold making resins is that the specific properties of the mold to be produced can be precisely matched to the later application. Furthermore, by taking an impression of a master model, several equivalent molds can be produced cost-effectively.