... PP,PE,PVC,PET,ABS,PPR for Plastic Extruder Machine Conical Twin Screw and Barrel material: bimetallic layer PP,PE,PVC,PET, ... powders being sprayed and welded on the screw's ridge,and uses different alloy and welding methods for the screw of different functions. ... treatment 2)special anti-wear & abrasion alloy (bimetallic)3)tungsten carbide;4)cobalt base alloy5)stainless steel 6)Gh113 nickel based ...