Plastic Profiles
Plastic profiles are extruded stock shapes of plastics including HDPE, polystyrene, butyrate, vinyl, PVC, LDPE, nylon, polyurethane, acrylics and fiberglass. Different materials hold different advantages: acrylics, for example, offer exceptional chemical resistance while polystyrene offers good adhesive capabilities. PVC is the most common type of plastic used for plastic profiles due to its flexibility, allowing it to be used for numerous applications. Including different plastic shapes such as thin film, rod, wire sheet, trim, channels, rods, tubing and gaskets, plastic profiles are available in a wide range of shapes and sizes. Plastic profile extrusions can be hot extruded, cold extruded or warm extruded through a die in either indirect or direct extrusion process. Each of these processes has their own benefits and drawbacks. Extruded plastic profiles are highly versatile and can be designed for specific applications such as pipes, hosing, fridge and freezer parts, packaging, gas and water piping, protective covers, light diffusers, display stands and point of sale holders. Serving industries including construction, medical, aerospace, office furniture, industrial manufacturing and transportation, most plastic profile extrusion companies also offer secondary services such as heat treating, printing, labeling, welding, anodizing and electroplating.
The extrusion process begins with raw plastic pellets or flakes being fed into a hopper placed atop a closed extruding channel; gravity feeds the raw plastic material down into the extruding channel. Running through the length of the channel is a screw conveyor which moves the raw plastic along towards the opposite end, shearing and heating the plastic through friction. Plastic pellets "plasticize", or melt, as they move through the conveyor and as they near the end of the channel, the molten plastic leaves the screw and travels through a screen pack in order to remove any contaminants. The screens are reinforced by a breaker plate, which is a thick metal puck with many holes drilled through it. A die is secured on the end of the conveyor channel which forms the molten plastic into a specific profile as it is pushed, or "extruded" through by the screw conveyor. The newly formed plastic profile is instantly cooled with cold water, pulled through by a series of conveyors and cut to appropriate lengths. In this way plastic profiles are manufactured quickly and at fairly high volume. Plastic profiles can be made using various types of extrusion processes including reverse extrusion, in which the thermoplastic material is made to flow in the opposite direction of the screw; and co-extrusion, in which multiple layers are extruded together. In addition there are two main ways in which plastic profiles can be extruded: hot working and cold working. In cold working, plastic deformation is imparted to the thermoplastic material at room temperature or near room temperature. Hot working uses heated thermoplastic materials with good deformability.