A compounding extruder solution for developing innovative plastic blends and alloys has come from an unlikely quarter in Niigata Machine Techno (Niigata, Japan), best known as a manufacturer of injection molding machinery and metal machining centers. The High-Shear Processing Extruder was unveiled at the recent IPF show in Japan.
The extruder employs separate plasticizing and high-shearing units, enabling individual processing conditions to be selected. Materials to be compounded are first melted in the plasticizing unit, then injected into the high-shearing section, which incorporates an automatic shut-off system with valve gates at both the inlet and outlet. The materials are then confined to the high-shearing section for as long as required for compounding. The materials circulate through the screw that exerts simultaneous shear and extensional flow during melt blending, and then back through the center of the screw for repeat cycling. Maximum screw speed is 3000 rpm....