Could you imaginge the world without computers, medical equipment, toys, cookware, sports equipment and clothes? Suppose you could step inside a time machine and go back 60 or 100 years. You may easily convince yourself a day without cars, telephones, and television–maybe even computers–might be kind of fun. Have you thought about the little things, though? Little things are often what are missed the most. How would you clean your teeth for instance? Toothbrushes are made out of plastics. You would not even wake up in time in the morning. Have a look at your alarm-clock. How many parts made out of plastics does it have? Without plastics there would not be any means of transport. A huge number of parts for airplanes, cars, ships and trains are made out of plastics. But where do plastics come from? The first synthetic plastic was made from the plant material cellulose.
In 1869, John Wesley Hyatt, an American printer and inventor, found that cellulose nitrate could be used as an inexpensive substitute for ivory. The mixture could be plasticized with the addition of camphor. Celluloid, as this new material was called, became the only plastic of commercial importance for 30 years. It was used for eyeglass frames, combs, billiard balls, shirt collars, buttons, dentures, and photographic film. In 1951, two young research chemists for Phillips Petroleum Company in Bartlesville, made discoveries that revolutionized the plastics world. Today, the plastics they discovered–polypropylene and polyethylene–are used to produce the vast majority of the thousands of plastics products all over the world. The raw material for plastics is petroleum. The word plastic comes from the Greek word plastikos, meaning “able to be molded.” Plastics can be processed in many ways. The main process used to form plastics is called extrusion molding. A heated plastic compound is forced continuously through a forming die made in the desired shape (like squeezing toothpaste from a tube, it produces a long, usually narrow, continuous product). The formed plastic cools under blown air or in a water bath and hardens on a moving belt. Rods, tubes, pipes, and sheet and thin film (such as food wraps) are extruded then coiled or cut to desired lengths.