INJECTION MOLDING PROCESS TO PRODUCE ARTICLES OF EXPANDING OR NOT EXPANDING PLASTIC MATERIAL

摘要

Injection moulding process to produce articles of expanding or non -expanding plastic materials involves (a) creating an overpressure inside the mould by the forded inlet of air and (b) then injecting plastic material into the so pressurised mould while the air escapes from the mould in volumes corresponding to those of the injected material, for maintaining a constant overpressure inside the mould.