... is made up of primary screw, secondary screw, butane pump, extruding mould head, molding device, traction machine and take-in machine. ... material. In the extruding process, vesicant is injected at high pressure. After the extrusion, foaming, cooling, molding and traction, it ... is collected as finished product. After being molded in the vacuum condition, it can be made into various packaging vessels, ...