A plastic product is a thing made of plastic that has a use. Since the development of the first plastic materials, the plastic research and development industry has exploded. Today, so many different plastic varieties exist that it can sometimes be difficult to distinguish them from each other. Also, plastic substitutes for other materials like glass and metal can reproduce the qualities of those materials so accurately that they are sometimes confused for them. Acrylic plastic, for example, is characterized by its high optical clarity and is often used as a substitute for glass. Other plastic materials like PVC have also displaced traditional materials. Washers and plumbing pipes, which historically have been made of metal, are increasingly made of plastics like PVC. In addition to their capacity as alternatives to existing materials, the development of plastics has made possible the creation of products that never existed before. For example, plastic is almost universally the material of choice for the fabrication of non-conductive circuitry substrates.
There are many processes by which plastic products can be created. Extrusion is one of the most prominent plastic manufacturing processes. Extrusion involves heating and pressurizing a stock of raw plastic material and forcing it through a specially-shaped tool called a die. In the context of extrusion, a die is a hole cut out of a metal plate; when molten plastic is forced through the hole, it takes its shape. When the plastic emerges on the other side of the die, it is newly extruded plastic. A plastic cutting process can then separate extruded plastic pieces from each other, and the pieces can then be shipped to customers or sent for additional processing. This process can be used only in the creation of plastic profiles. In order to create more complex shapes, a molding process must be used. Plastic molding processes also involve heating and pressurizing raw plastic, but they differ from extrusion in that they involve the injection of the plastic into a carefully shaped, hollow mold cavity. In addition to these thermoforming processes, mechanical shaping processes like machining are also used to form plastic products. There is virtually no limit to the number of possible plastic products.