What is the classification of screw extruders? What are the characteristics?
2018-09-12 10:07:27
PC special screw: for PC and other high viscosity plastics, less shear heat, acid corrosion resistance, medium and small diameter, molding PC, PP-R, flame retardant ABS and other good results. It can also produce ordinary plastics and PMMA common products. Mixing effect is poor. For example, adding color toner in plastic, we need to make a reinforced color mixing screw.
PA special screw: In view of the low viscosity of PA, difficult coloring, fast melting speed, good self-lubrication and other characteristics, screw mixing effect is good, feed quantity is stable, good exhaust effect. Intermediate diameter. Molding PA, PP, LCP and other crystalline low viscosity plastic effect is good. Plastic can also be molded. For PC, PMMA flame retardant ABS and other plastics with high viscosity and poor thermal stability is not applicable (middle temperature is too high, decomposition)
PMMA special screw: PMMA transparent products require good plasticization effect, low decomposition rate and other characteristics, good plasticization, low shear heating, good mixing. Medium diameter molding PMMA, PP-R, PC, ABS and other color powder effect is good, such as plastics with flame retardant, screw chromium plating.
UPVC special screw: For UPVC high viscosity, easy decomposition, strong corrosiveness and PVC pipe joints require good plasticization and other characteristics. The screw has good plasticizing, less shearing heat and acid corrosion resistance. Because there is no apron, it can not be used for low viscosity plastics and injection speed and pressure classification of more accurate products. In addition, due to the need to cool down heat, do UPVC products barrel (melt tube) to adopt forced air cooling measures and screw with the use of.
PET special screw: for PET viscosity is low, specific heat capacity is large, easy to stick materials and PET bottle blank requirements of rapid plasticization, plasticization uniform characteristics, screw plasticization, high stability, non-sticky, melting glue speed, the bottle blank made by blowing high yield. Large diameter can also be molded into general plastics.
PBT special screw: In view of the easy decomposition of PBT, pressure sensitivity and the need to add glass fiber characteristics, screw pressure stability, and the use of double alloy to improve wear resistance.
Acidic screw assembly: In view of the strong corrosiveness of acidic plastics such as CP, CA, screw, melt tube and other plasticized parts have been specially designed in structure and surface treatment. The screw assembly has good corrosion resistance.
