In the advent of industrial technologies, technical knowledge and engineering skills, it is possible to convert plastic resin in any shape. Plastic comes in different shapes, colors and designs, and its application is widespread in homes and different industries. Plastic extruder machines have unique features and they widely used by industries for shaping products using plastic extrusion process. The manufacturing process of handling large volume of raw plastic is called plastic extrusion process, wherein plastic is melted and shaped into a continuous profile, producing plastic sheeting, wire insulation, plastic films, pipe or tubing, deck railings, weather-stripping, fencing, thermoplastic coatings and many more.
The process of plastic extrusion starts by feeding plastic materials such as plastic powders, pellets, granules or flakes from a hopper into the plastic extruder machine’s barrel. The resin is melted into polymers using mechanical energy generated by turning screws and by heaters arranged across the barrel, shaping the polymer into pipes hardening during cooling. A plastic extruder machine consist of a feed screw, temperature controller and barrel, and its features and design are based on the type of material to be extruded and the product design. Various types of polymers have different screw designs and most screws have a feed, melting, metering, decompression and second metering zones. The feed zone is also known as the solids conveying zone wherein the resin is fed into the extruder, with the same channel depth all throughout the zone. The melting zone is also termed as compression or transition zone, where the polymer is melted and there is a progressively smaller channel depth. The metering or melt conveying zone of an extruder machine is the zone melting the last particles, mixed to a uniform composition and temperature, with constant channel depth. The channel in decompression zone of an extruder machine gets deeper suddenly, relieving pressure and allowing trapped gases to be drawn out by vacuum is called the decompression zone. Second metering zone has greater channel depth than first metering zone but are similar and it serves to repressurize the molten polymer to get it through the screen and die resistance.
Die types include blown film extrusion, sheet film extrusion, tubing extrusion, overjacketing extrusion, coextrusion and extrusion coating. Blown film uses annular, spider and spiral plastic extrusion processes, and are used in manufacturing plastic films like shopping bags. The dies used for sheet or film extrusion are T-shaped and coat hanger, used to extrude plastics that are too thick to be blown. Tubing extrusion is used for manufacturing PVC pipes wherein positive pressure is applied in the internal cavities using a pin, and negative pressure is applied using a vacuum sizer outside the diameter to make sure the final dimensions are correct. You can visit our website for more information.What Do You Know About Machines