How to increase the life of conical twin screw extruderHow to increase the life of conical twin screw extruder
Compared with the general single-screw extruder and parallel twin-screw extruder, the counter-rotating conical twin-screw extruder (hereinafter referred to as "cone twin") has its common feeding area, large shrinkage ratio, and the screw is in the longitudinal direction The shearing and mixing power of the material in the horizontal and horizontal directions is higher, and the plasticization can be more excellent. Therefore, it is particularly suitable for products that use high calcium filled PVC powder as a material to produce plastic profiles.
Inorganic calcium carbonate and titanium dioxide, which are not small in size and high in hardness, participate in a relatively high, or even reach 150%, and recycled plastic mixed with many impurities is often used as the main material. Barrels and screws are increasingly unsustainable in the solid-phase conflict with these materials; in order to obtain better plasticizing ability, the materials are pushed from the large inlet of the extruder planned by the super-cone to the smaller extruding end. This solid-state conflict has intensified.
The wear of the small hole end of the barrel and the small diameter section of the screw is particularly severe, because the back pressure received by the screw is greater than that of the general single-screw extruder and parallel twin-screw extruder. The excellent plasticizing ability is obtained within the moving interval, the specially planned screw helix angle, screw pitch, meshing clearance, etc., intensify the shear wear received by the screw.
And when the thrust bearing in the distribution box may be slightly worn due to being overwhelmed, it will also cause the side of the screw edge of the screw to collide with the side of the adjacent screw edge in the axial direction, and it will even fall into the rock; we must also Speaking of the corrosion of the chloride ions released by PVC during the plasticizing process on the barrel screw, etc., these are all factors that cause the service life of the core components of the conical twin-screw extruder to be more severe.