single blown film extrusion screw barrel 

This figure provides a schematic representation of a simple metering screw. It is composed of three main sections; the feed section, transition section and metering section. The feed section, which is often also referred to as the conveying zone, is responsible for conveying materials (pellets, fluff and powder) forward to the transition section. The transition section is the portion of the screw where the majority of the melting takes place. The metering section, also called melt conveying or pumping zone, delivers the melt toward the discharge end of the extruder. Process. *Plastic melt is extruded through an annular slit die, vertically to form thin walled tube *Air is introduced in the centre of the die to blow up the tube like a balloon(IBC) *Air ring blows onto the hot film to cool it…