Plastic Material

|Just about everyone knows that plastic valves, pipes, tanks, and fittings are molded, but there ís a bit more to it than that. Knowing something |
|about the processes that are used to produce these products will help to make you more knowledgeable in selecting and using them in various |
|applications. |
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|Extrusion |
|Pipe is one of the more common types of plastic product we are familiar with. Pipe is produced by an extrusion process. Basically extrusion can be |
|defined as forcing a material through a die orifice. This die orifice produces the final shape of the finished product. It is probably a bit of over|
|simplification, but extrusion is somewhat analogous to squeezing toothpaste through a tube. |
|An engineering explanation of plastic pipe extrusion would be something like this: plastic pellets or granules are thermally fluidized, homogenized |
|and continuously formed. Or, in other words, plastic resin granules are heated and melted, then mixed and formed into pipe. Pipe is not the only |
|product produced by the extrusion process. Plastic tube, sheet, wire and profile shapes are all also manufactured by this process. In fact, the |
|plastic resin granules or pellets used for injection molding are produced by extrusion. A long strand or filament of extruded plastic is chopped or |
|cut into pellet-sized