US Patent 7163390 Machines and process for injection-moulding plastic material

In the molding of parisons made of thermoplastic material for making bottles for containing effervescent beverages, resistance to bursting of the bottles is increased considerably the gasket (4) between the injector nozzle (3) and the injection cavity (1) is made of thermally insulating material and has a shape that is complementary to the shape of the cavity (1) for housing the end of the injector (3) in the injection cavity (1). Cutting of the sprue in specific conditions increases still more the resistance to bursting.