a transparent mold system allows rapid and economical production of thermoset fiber reinforced plastics and other thermoset resin parts by heating with visible light energy without using an autoclave , photosensitive resins , or ultraviolet sensitive chemical curing agents . molding times are accelerated to minutes instead of hours , and the molds are made of transparent plastics materials that can be economically produced by injection , casting , vacuum or pressure forming to replace metal molds and laid - up frp molds .