Compared with the parallel co-rotating twin screw extruder, conical counter-rotating twin screw extruder can be described “section-material-type”equipment with low speed and low power consumption. It normally uses the non-combination screw.
Compared with general conical twin screw extruder, the screw of conical counter-rotating twin screw extruder used of WPC production should have larger and longer material feeding part in order to fit the requirement of small percentage of wood flour and plant fiber but larger filling portfolio of them. Besides it can reduce the shearing of wood fiber and make the wood fiber distribute uniformly and material melt fully, so it would fit the wide range of production.
If the wood flour and plant fiber has a large feeding amount and the melted resin has a strong rigidity, it would have a requirement of a resistant high-pressure gear box, and use the screw which can compress fast, melt quickly and have a short metering part. Thus it can be ensured that the wood fiber has a short resident time and the screw cannot be broken away and has no degradation of performance.