... co-extrusion line SJ150 signle screw PE sheet co-extrusion line PE sheet co-extrusion line PE sheet production line Specifications :PP PS PE sheet co-extrusion ... alloy : in the smaller models , is made by nitrided steel as standard , by two-metal alloy as optional , ... solidly made of electro-welded pieces , special covers in stainless steel , easily removable , protect the heater cylinder zones . The ...