the chances of seeing pet preforms in life are still quite large. Below, the preform manufacturers will lead you to understand the pet preforms. Pet preforms are typical injection molding products, easy to transport, mostly PET material, uniform texture, good insulation, is the intermediate product of PET bottles, oil barrels. In general, pet preform injection needs to pay attention to the following aspects:
Note 1: Injection speed
Generally, the injection speed is fast, which prevents premature coagulation during injection. But too fast, the high shear rate makes the material brittle. The shot is usually completed in 4 seconds.
Note 2: PET treatment
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. 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. Airborne methods can be used to verify that the material is completely dry. The proportion of recycled materials should not exceed 25%, and the recycled materials should be thoroughly dried.
Note 3: Staying time
Do not use excessive residence times to prevent molecular weight degradation. Try to avoid temperatures above 300 °C. If the shutdown is less than 15 minutes. Only need to be air-blasted; if it is more than 15 minutes, clean it with viscosity PE and reduce the temperature of the barrel to PE temperature until it is turned on again.
Note 4: 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.
Nowadays, there are many pet product suppliers in the market. You may wish to choose Jilian Plastic Mould. We are a China Pet Bottle manufacturer with rich experience in the market. With many years of experience in the market, we can provide you with products and products. service.