What are the methods of PET bottle blow molding?
(1) the polyester bottle can be divided into the following four molding methods according to the molding process.
Iv injection stretch blow molding.The bottle blank is shaped by injection process and then stretched and blown.
Stretch and blow molding method for extrusion tube.The pipe is made by extrusion process, the pipe is cut off, sealed and made into bottle blank.
Extrusion injection stretch blow molding method.The PET resin was fused and plasticized by the extruder, and squeezed into the injection cylinder, and then injected into bottle blank (secondary injection), and then stretched and blown.
Extrusion extrusion blow molding method.PET resin was extruded and compressed into the mold by extrusion process, and then stretched and blown.
(2) in accordance with the steps of molding process, there are three molding methods of polyester bottle.
One step method.Polyester bottles in the same machine molding processing.When forming, the blank is not completely cooled under the condition, that is, stretching and blowing.
Two - step method (cold bottle blank method).The polyester bottle is formed and processed in two machines, and the bottle blank is formed and the bottle blank is stretched and blown, which is divided into two steps.The preform to be made is cooled to room temperature;Then heat the blank to stretch and blow.This method, although the process steps, the number of equipment, but the molding process easy to control;Lower equipment purchase cost;Bottle molding and stretching and blow molding are respectively carried out, which is conducive to professional and large-scale production.
Three steps method (cold bottle blank method).Mainly refers to the extrusion tube stretching and blow molding method.It will pipe molding, bottle blank manufacturing, stretching blow molding, into three process steps.