There can be no doubt that this is an age of plastics...
Last Updated On: Monday, October 11, 2010
There can be no doubt that this is an age of plastics. The word covers a whole range of materials, used in the manufacture of a host of everyday articles from tools to garments. On this page there are variety of familiar objects made of plastic. Synthetic materials are man-made substances, which have never existed in the natural state. They come from the organic chemist's laboratory and include synthetic rubber, rayon, nylon, celluloid - and the whole range pf plastics. Plastics are derived from hydrocarbon compounds often obtained from petroleum, and have found their way by now into every corner of modern technology and daily life. The development of synthetic materials began when Braconnet in France (1833) and Schoenbein in Switzerland (1845) prepared nitrocellulose. A whole series of new artificial substances then began to appear on the market, meeting every kind human need.
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|Ebonite is a type of plastic obtained by treating rubber with sulphur in the ration 100:32. Its name is derived from the word 'ebony'. Many fountain pens are made of ebonite. It is also called vulcanite. ||In 1869 an American, John Wesley Hyatt, discovered how to make celluloid from nitrocellulose and camphor. It was the first plastic to be commercially successful, being enormously useful to the photographic industry. ||Casein plastic rivaled Bakelite but it softens in hot water. It was first manufactured in 1885 when pure casein was treated with formaldehyde. It was used as a substitute for horn, celluloid and ivory. |
|The Belgian chemist Baekeland discovered and patented the synthetic resin Bakelite in 1909. Unlike more modern plastics, it does not soften when heated. Electric plugs are made of Bakelite. |
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|Above is shown the injection moulding process used to manufacture thermoplastics such as the vinyl's, polyethylene and plexiglass. Because they lose their rigidity when heated they are especially suitable for printed matter, laminating and manufacture of threads. The process is shown starting with the empty mould and ending with the finished article. ||The diagram above shows the commonest type of compression moulding used for thermosetting materials, which, as their name indicates, reach the necessary degree of hardness when they are subjected to an irreversible heating process. Bakelite is one of these materials. |
A type of injection moulding machine used for manufacturing plastic objects. Finely powdered plastic is put into the feed hopper at the top and heated so that it becomes soft and can be moulded. The cooling process is very quick and after a few seconds the mould is opened and the finished object removed.