Extruders are machines that use the physics of friction and pressure to partially melt, or plasticize, raw plastic material, squeezing the molten material through a shaping die at the outputting end.
During the extrusion process, gravity feeds plastic pellets or flakes through a hopper down into the extruder’s enclosed screw conveyor channel. This conveyor moves the raw plastic along toward the opposite end, shearing and heating the plastic; electric heaters built into the conveyor often aid the melting process.
The molten plastic is formed into a specific profile as it is pushed, or extruded, by the die at the open end. The newly formed plastic profile is instantly cooled with cold water, pulled through by a series of conveyors and cut to appropriate lengths.
Extruded plastics manufacturers use plastic extruders to make plastic profiles, plastic channels, plastic rods, plastic tubing and plastic sheets, all of which play a vital role in virtually every industry, from the consumer products manufacturing industry to the medical device development industry.
Plastic channels and profiles can be manufactured continuously and are used in window profiles, building siding and trim, gutters and channels, sealing sections, hoses, curtain rods, tubes, pipes, drinking straws and many other common products.
Extruded plastic sheets are used in packaging and are often thermoformed into consumer products and packaging. Plastic rods and thick gauge sheets are machined by automotive, aerospace and construction industries into parts for close tolerance applications.
The extrusion process is highly customizable and is capable of high volume production as well as short runs, making plastic extrusion one of the most diverse and economical methods of plastic fabrication.
Plastic extruders can extrude any thermoplastic material (that is, plastic material that changes its form under various levels of heat), including HDPE, LDPE, PETG, PVC, butyrate, vinyl, polypropylene and polystyrene.
The plastic extrusion process is responsible for the production of everyday necessities like PVC pipes, indoor and outdoor window trim, sealing bars, siding, plastic gutters, plastic sheeting, toys, recreational accessories, and much more.
Since the extrusion process uses a continuous output of smooth, thoroughly heated and mixed material, extruded plastics seldom have bubbles or inconsistencies, and they are therefore valued for their structural integrity and consistent, precise profiles.