Mfg. shaped articles with foamed core and smooth thermoplastic skin - by covering foam core material with thermoplastic layer and heating assembly in mould

摘要

A body having a foam core and a skin of thermoplastic material on at least one side is made by applying a covering layer of the skin material to the foamed core and heating the assembly in a mould at a temp. at which the core is held or shaped into a desired shape and the thermoplastic material has a low viscosity and forms into a closed smooth skin. The foam core is e.g. of polymethacrylimide, PVC, or polyurethane. The skin is e.g. of a semi-crystalline thermoplastic with a m.pt. below 200 deg., C or an amorphous thermoplastic having a sufficiently low viscosity at 180-200 deg. C, esp. where the thermoplastic is polyvinylidene fluoride, polyethylene, polypropylene or polycarbonate. Alternatively the skin may be e.g. of polyetherimide, the skin is heated to 250-310 deg. C e.g. by short and rapid heating of the skin while the greater part of the core is not hotter than 200 deg. C. An outer layer, esp. of polymethyl methacrylate, may be applied to the skin to improve the mechanical strength, rigidty, chemical resistance and scratch resistance and to provide the body with a certain reflectance.