| 摘要 |
This new "mouldless" moulding method, comprises (1) prepg a trim cover of a surface material such as a cloth and a backing material having a low m.pt. (2) putting the trim cover into an outer-shape-retaining member (3) heating and pressing the trim cover to obtain a mould cover having the shape of the outer profile of the final product (4) pouring a highly reactive polyurethane compsn capable of foaming at a low inner pressure into the mould cover (5) foaming and swelling the compsn until it fully fills the internal cavity of the cover (6) externally heating the cover to a temp equal to or near the m.pt. of the backing material, thus shrinking the backing material (7) at the same time allowing the polyurethane to expand so that it adheres to the inner surface of the surface material and becomes integral with it. At (1) the surface material can be furnished with a backing material before shaping, or when the surface material has been shaped, the shaped backing material can be fixed to it. The low m.pt. backing material is polystyrene foam or a mixt. of polystyrene and polyethylene, which adheres to the inner surface of the surface material. The backing material is furnished with pinholes to allow deaeration. At (6) heating electrically or by a blow of hot air is followed by cold air cooling before shaping. The reactive polyurethane compsn is specified to have a low inner pressure and a rapid reactivity. It is poured into the mould cover after being thoroughly melted. |
