Medical Material Pet Extruder Machine , Double Stage Plastic Granules Machine
Usually the first compounding extruder runs at a high speed for good mixing and high output capacity.The second extruder must be a larger diameter single screw one that can run at lower screw speed .The lower screw can avoid over –heating by internal cooling system and strong heat exchange ability .The functional separation allows operator to more flexibly control the expectable material mixing process and temperature.
Formula:
1) PVC cable: PVC + 30% CaCO3 + DOP + additivesflame retardant + Talc
2) Rigid PVC for pipe fitting: PVC + 15% CaCO3 + additives
3) Transparent PVC for inject hose: PVC + DOP + additives
4) Rigid PVC for window profile or Floor covering sheet:
PVC + CaCO3 + wood powder+ additives
There are several types of machine for Medical Material Pet Extruder Machine , Double Stage Plastic Granules Machine :
1) Tandem extruder:
The first stage is co-rotating parallel twin screw extruder and the second stage is single screw extruder (please check the attached layout and quotation). This is the most popular process in the world now.
PVC is very sensitive material about the temperature. It is very easy degrade at high temperature. By co-rotating twin screw extruder, the material have the best dispersion than the other machine because of the high screw speed (about 250~400rpm). But the temperature of melt material is also high, so we need one single screw extruder for cooling down the material fast, then extruding for pelletizing.
It is with modular structure for screw and barrels. You can change the screw sequence easily for different formula. Even some screw elements are wear out after some years, you just need to change the elements for new one.
2) Counter Rotating Conical Twin Extruder
Working at low screw speed (about 50~60rpm), the dispersion quality and output capacity is less than the same size parallel twin screw extruder.
Conical twin screw is unit-type structure. When you want to process different formula or repair the machine, you have to change the whole screws and barrels, much cost needed for future.
China best quality double stage extruder for Medical Material Pet Extruder Machine , Double Stage Plastic Granules Machine detailed pictures:
