Extrusion is a manufacturing technique used to form thermoplastic compounds into unremitting products such as sheeting, rods, cast film, tubes, filaments, cable, cord, mono filaments, synthetic fibers, hollow sections for blow molding, compounding, reclaim 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.
Professional Rapid PrototypingIn this technique, plastic chips or pellets is first loaded and fed into a long heating chamber through which it is stimulated by the action of a continuously revolving screw.
At 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 immersion in water.In the process of wide film or sheeting, the plastic is molded in the form of a tube.
This tube may be split as it comes from the die and then stretched and thinned to the size desired in the finished film and in the case of wire and cable coating, the thermoplastic is thrust out around a continuing length of wire or cable which like the plastic, passes through the extruder die.