Injection-moulding process for producing injection mouldings from thermoplastics and a split injection mould for carrying out the process

摘要

The injection-moulding process for producing injection mouldings from thermoplastics is used in various branches of industry for producing high-strength, textured products and comprises filling the communicating cavities (4 and 5) of a split injection mould successively with the polymer injection-moulding compound, keeping it under pressure and cooling it. During the pressure-holding time and cooling in this operation, the polymer injection-moulding compound is forced through the cavities (4 and 5) at a temperature exceeding the polymer melting or flowing temperature by a maximum of 40-50 DEG C and at a pressure of 900-3000 kp/cm<2>. The moulding surfaces of the injection mould are cooled in a range from -20 DEG C to the initial melting or flowing temperature of the polymer. In the split injection mould, which comprises mould halves with a female mould and a male mould, known heating elements are arranged in the region of the inlet and outlet openings and are insulated from the remaining part of the mould halves. <IMAGE>