how to inject PET preform
PET chemical name is polyethylene terephthalate, also known as polyester. At present, GF-PET is the most used among customers, mainly for preform injection. The rheology of PET in molten state is better, and the effect of pressure on viscosity is greater than temperature. Therefore, the fluidity of the melt is mainly affected by pressure. Plastic Processing Due to the presence of lipid based PET molecules, and it 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. In this case, the material must be dried before processing, and the drying temperature is 150 ° C, more than 4 hours, generally 170 ° C, 3-4 hours. The proportion of recycled materials should not exceed 25%, and the recycled materials should be thoroughly dried. Injection Molding Machine Since PET has a stable time after melting point and a hi