Extrusion is a manufacturing technique used to form thermoplastic compounds into unremitting products such as sheeting, rods, cast film, tubes, filaments , cable, cord, monofilaments , synthetic fibers, and hollow sections for blow molding, compounding , reclaiming of plastic pellets, and to coat wire. An extrusion mechanism includes twin screw systems, which are generally used for PVC pipe or profiles, and single screw systems, which are used for these and other extruded products. In this technique , plastic chips or pellets are first loaded and fed into a long heating chamber through which it is stimulated by the action of a continuously revolving screw. On the opposite of the heating chamber , the molten plastic is forced out through a small hole or dies with the shape desired in the finished product . As the plastic extrusion comes from the die, it is fed onto a conveyor belt where it is cooled, most frequently by blowers or by i...