How many types of special screws are there? (2)


1. PET special screw: for PET low viscosity, large spec […]

1. PET special screw: for PET low viscosity, large specific heat capacity, easy-to-stick materials and PET preforms that require fast plasticization and uniform plasticization, the screw has good plasticization, high stability, non-stick materials, and fast melting speed. The finished product rate is high when the preform is blown. Large diameter, general plastic can also be molded.
2. PBT special screw: In view of the characteristics of PBT that is easy to decompose, is sensitive to pressure and needs to add glass fiber, the screw produces stable pressure and uses double alloys to improve wear resistance.
3. Acid screw components: For the corrosive characteristics of acid plastics such as CP and CA, the screw, melt barrel and other plasticized parts have been specially designed in structure and surface treatment. The screw assembly has good corrosion resistance.
4. Double alloy screw: For recycled materials with a lot of impurities, glass fiber reinforced plastics and plastics with a lot of inorganic mineral fillers (calcium powder, carbon powder, talc, etc.), the screw has good wear resistance.
5. UPVC special screw: for UPVC high viscosity, easy to decompose, strong corrosive and PVC pipe joints require good plasticization, etc. The screw has good plasticization, low shear heating, and acid corrosion resistance. Because there is no rubber ring, it cannot be used for low-viscosity plastics and products with relatively high injection speed and pressure classification. In addition, due to the need for heat dissipation and cooling, the barrel (melting barrel) of UPVC products should be used with forced air cooling and screw.