When choosing an injection - molding machine for PET (polyethylene terephthalate) material products, consider the following points:
Clamping force
• PET products usually have relatively thin - walled structures. But depending on the size and shape of the product, calculate the appropriate clamping force to prevent the mould from opening during injection and ensure the quality of the molded product.
Injection unit
• Screw design: PET is a hygroscopic material. A screw with a good - quality barrier or venting design is preferred to remove moisture and ensure the homogeneity of the melt.
• Injection volume: Make sure the injection volume of the machine can meet the requirements of the product's size and weight. The injection volume should be sufficient to fill the mold cavity completely.
Temperature control system
• PET requires precise temperature control during the injection - molding process. The temperature range usually is around 260 - 290°C. The injection - molding machine should have an accurate and stable temperature - control system to ensure the material is in the best - flowing state.
Injection speed
• PET material has a relatively narrow processing window. A suitable injection speed can avoid problems such as jetting and short - shot. High - speed injection may be required for some thin - walled products, but it also needs to be adjusted according to the actual situation to ensure product quality.
Mold compatibility
• The mould used for PET products should match the injection - molding machine in terms of size, installation method, and cooling system. Ensure that the machine can provide the necessary mold - opening and - closing stroke and force to operate the mold properly.