In this process, glass-fibre mats are cured in the moulds via manual impregnation with polyester resins (UP resins). Particularly high strength can be achieved via this method. Curing usually takes place at room temperature. This process is mainly used for smaller series and larger component geometries, as well as for mould making and prototypes of all kinds.
In this process, layers of dry glass-fibre scrims are draped in a single-shell mould. In the next step, the mould is sealed with a vacuum bag. Liquid resin, usually epoxy resin (EP resin), is injected into the mould under vacuum.