Apr 24, 2013

Man-made Fibers

The textile industry is literally as old as civilization but until the end of the 19th century there was virtually no change in the raw materials it utilized. These were primarily the natural vegetable fibers cotton and flax and those of animal origin - wool and silk. The first break with tradition came around the turn of the century, when C.F. Cross and E.J. Bevan in 1892 invented viscose rayon, made by a chemical process from cellulose. Manufacture was first taken up in Britain by Courtaulds in Coventry.

By the mid-1930s world production of rayon (largely viscose rayon) was around 750,000 tonnes a year, comparable with wool at around 1.5 million tonnes, but far short of cotton at over 6 million tonnes. Nevertheless, rayon was sufficiently big business for the chemical industry to explore other possible manmade fibers, especially wholly synthetic ones.

The first to achieve a major success was Du Pont in the USA, where in 1935 W.H. Carothers discovered the fiber-forming potential of polyamides (a kind of polymer). To transform these into a marketable product was a difficult task but Nylon 66 came on the market in 1939. It was an immediate success, especially in the stocking market: nylons and stockings soon became virtual synonyms. Later, nylon was used in many other ways - in fashion fabrics, ropes and fishing lines.

In Britain a chemically different sort of fiber - a polyester - was patented in 1941 but was not substantially developed until after World War II. It was marketed by ICI in Britain and the rest of the world, except the USA, as Terylene; in the USA as Dacron. This found many applications in the clothing industry, as fabric and knitwear but not as stockings; like rayon its relaxation time was wrong so that stockings bagged. (Science A History of Discovery in the Twentieth Century)