1. Processing of raw materials

Since the PET macromolecule contains a lipid group and has a certain hydrophilicity, the pellet is sensitive to water at a high temperature. When the moisture content exceeds the limit, the molecular weight of the PET decreases during processing, and the product is colored and brittle.

Therefore, the material must be dried before processing, and its drying temperature is 150 ° C, more than 4 hours; generally 170 ° C, 3-4 hours. Airborne methods can be used to verify that the material is completely dry. The proportion of Pet Preform Mould reclaimed materials should not exceed 25%, and the recycled materials should be thoroughly dried.

2. Injection molding machine selection

Since PET has a stable time after melting point and a high melting point, it is necessary to use an injection system with more temperature control sections and less self-friction heat during plasticization, and the actual weight of the product (aqueous mouth material) cannot be less than the machine injection. 2/3 of the amount.

3. Pet preform mold and gate design

PET preforms are generally molded with hot runner Pet Preforms molds. It is best to have a heat shield between the pet preform mold and the injection molding machine template. The thickness is about 12mm, and the heat shield must withstand high pressure. Exhaust gas must be sufficient to avoid local overheating or chipping, but the depth of the exhaust port should not exceed 0.03mm, otherwise it will easily produce flash.