Engineering plastics are a certain grade or class of polymer resin that is used for its strength, durability and resistance properties. They are usually rigid and tough with low creep and high thermal stability. They are not considered thermosets, which irreversibly cure and cannot melt once they have cooled and dried.
Related Categories
Under the category of thermoplastics, engineering plastics includes polydactyl, polyamide, polycarbonate and polysulfone. They are used most commonly as alternatives to glass, wood and metal and are used as plastic parts and products rather than as containers, bags and packaging materials, like other more flexible plastics. Engineering plastics are fabricated into products for the automotive, sporting goods, plumbing, hardware and construction industries as well as any application requiring a hard, rigid and strong part. Products like motorcycle helmets, skis, car bumpers, dashboard trim and small pieces of hardware like plastic washers, screws, nuts and bolts are often made of engineering plastics because of their impact resistance, mechanical strength and flame retardancy, which are qualities that not all metals or wood materials possess. This type of plastic obtains its strength and resistance from additives that are mixed in with the plastic resin.
Despite their strength properties, engineering plastics are still easily formed into almost any shape, usually through the application of heat. When the plastic has been melted and dried, it can melt many more times, unlike thermoset plastics. To produce flat, rigid parts, sheets of plastic are altered many different ways. They can be stamped, welded together with a laser or application of heat and pressure, bent, cut or engraved. Larger, more complex plastic parts are formed using a mold or die. During these processes, the plastic is either heated until molten or soft and can be injected into a cavity or draped over a mold. Vacuums are often used during these processes to ensure the plastic perfectly conforms to the shape of the metal die without any air pockets. Engineering plastic manufacturers are often involved in the design, fabrication, assembly and sometimes packaging processes. They specialize usually in a certain type of plastic or products made for a specific industry, such as automotive manufacturing or marine.
