Thermoforming synthetic parts with complex curved surfaces partic. transparent polycarbonate for automobile use - by placing blank between flexible gas tight membrane and former of required shape made from rigid porous body coated with gas permeable surface and drawing vacuum through the porous body causing membrane

摘要

Mfr. of a synthetic material part with complex curved surface from a flat blank comprises cutting out the flank (1') and then thermoforming it by inserting between a rigid mould (13,18) with a surface (21) of the required shape and a gas tight flexible membrane (23). The blank is pressed against the former surface(21) by drawing a vacuum between it and the flexible membrane and/or applying an external pressure to the membrane. USE/ADVANTAGE - Thermoforming of parts both transparent or not but partic. transparent polycarbonate for the automobile industry. Allows thermoforming of parts replacing glass in the automobile industry.