A Preform PET mould is a test tube shaped piece of plastic that is made by a process called injection moulding, using a plastic called PET.Meanwhile a mould is a shaped hollow piece of metal, a tool, that is used to control the shape of the item being moulded. The mould is what the molten plastic fills under pressure and then cools and goes hard retaining the shape described by the mould.So a PET preform mould is a mould used to make PET preforms.
Subsequently, and at a time convenient to a soda, or suchlike, bottling company, that preform will be reheated, and compressed air forced into it, thereby expanding the, soon to be former, preform to become the full shape of a bottle. That process is called Stretch Blow Moulding, not to be confused with Extrusion Blow Moulding.The injection mold is mainly composed of a pouring system, a molding part and a structural part.
Among them, the casting system and the molding part are the parts that are in direct contact with the plastic, and are the most complicated, most variable, and most demanding parts in the mold.Sometimes the two moulding processes, the injection and the stretch blow, are linked into a dual machine synchronizing the two processes, that is called Injection Stretch Blow Moulding.The powder or granular plastic is sent from the hopper of the injection machine into the heated barrel.
After heating and melting and plasticizing, the material will be compressed and moved forward by the thrust of the plunger or screw, and passed through the nozzle at the front of the barrel to It is injected into the closed mold cavity at a relatively low speed very quickly; after a certain period of cooling and setting, the mold is opened to obtain the product. The preform largely determines the quality of plastic bottles, and the importance of plastic bottles is self-evident. The functions of the injection molding machine mainly include: being able to install a mold of a given size, providing sufficient clamping force, operating according to the requirements of the cycle time, and plasticizing sufficient materials.