GIESSFORM

摘要

A die for injection or compression moulding or thermoforming of plastic materials, comprises a die body strength member (1, 2), heat insulating layers (4, 5) of an insulating material, heating layers (6, 7) of electrically conductive material provided on the cavity side of the heat insulating layers, and protective layers (8, 9) of abrasion-resisting material provided on the cavity side surface of the heating layers. The die body material may be soft-steel, or chrome-molybdenum or tool steel. The heat insulating layer material may be of glass powder, zirconia, or alumina. The heating layer material may be Ni-P, nichrome, TiN, TiC. The protective layer material may be of Cr, TiN, or TiC, of greater electrical resistance and better heat conductivity respectively, than the heating and insulating layers. The materials may be inclined (Fig 3) in each layer to prevent peeling and heat cracking. A plurality of separately heating systems may be provided with localised control/ thermocouples. <IMAGE>