ABSTRACT

Nylon , one of the most important man-made fi bres, was developed in the USA in the years just before the Second World War but made its glamorous debut to the public in the form of ladies ’ stockings in the spring of 1940. The production of polyethylene (polythene) started in England in 1941 and who today has not come across the ‘ polythene bag ’ . Both nylon and polythene are typical of the materials generally referred to as plastics , or more properly as plastics materials – but never as plastic materials because of course many substances, including metals, undergo plastic deformation when the applied stress is great enough.