What is a two-step extrusion stretch blow molding

Two steps out of stretch blow molding is also called cold tube stretch blow molding. It has a variety of forming method, the general forming process is: adding thermoplastic base out of the extruding machine, the melting, mixing, extrusion molding on the diameter of the pipe; Will finalize the cooling tubes according to the specified length cut off; Clamping tube, heating in the heating device; After hot temperature of tube, and within the tube embryos die, mouth, neck thread end compression molding, the other end was closed to the bottom of the tube embryo; Blowing tube embryo and stem were transposition in the blow molding mold; Tube embryo within the blow molding mold, was first blow rod longitudinal tensile, inject compressed air at the same time, the circumferential blowing tube embryo into a container; But after finalize the design of the container, and from blowing die out.