50mm Extruder Screw Barrel For PVC/R-PVC Cable Molybdenum Alloy Certificate ISO 9001 50mm Extruder Screw ... Barrel For PVC/R-PVC Cable For good plasticizing effect,we have different designs of ... Gradual type,mutant type,wave type,barrier type,double screen type,shunt type,separation type,exhaust type,pin type,mixed type,double-head type,three-head type,multi head type etc. ...