Author: Purple Brolly

Imperial Chemical Industries (ICI) was once the UK’s largest manufacturing company and from the 1930s to the 1960s its Plastics Division was a hub of innovation, some by design, some by accident (e.g. polythene). Other departments were also involved in producing new plastics that are still in use today, such as Perspex (ICI brand name).

In 1931 Dr John W.C. Crawford (1901-87) of the Explosives Division devised a synthesis (later known as the Stevenston Process) that led to the first commercial production of clear, tough PMMA sheets, named ‘Perspex’ in 1934. He had developed research from ICI’s Dyestuffs Division ~ an unlikely combination at first glance.

In 1933 Eric Fawcett (1927-2000) and Reginald Gibson (1902-83) at ICI’s Cheshire plant, found a white waxy  substance resulting from one of their explosive experiments in which they heated ethylene and benzaldehyde to 170°C in high pressure. This was the first polyethylene (a.k.a. polythene) synthesis but their work was halted by safety concerns.

However, in 1935, ICI colleagues including Sir Michael Perrin (1905-88) and W.R. Dermot Manning (1903-84) resumed the project with better equipment. Another fluke, whereby oxygen leaked into their ethylene mixture, created a white powder which was more amenable to mass production. Its insulation properties enabled the first airborne radar in WW2.

(Images: pipes by publicdomainpictures.net and 1956 Rolls Royce with perspex sunroof by Brian Snelson at Flickr.com / CC BY 2.0)

Dr. Brian Mercer (1927-98) was born in Blackburn towards the end of the British textile industry’s golden age. Fortunately, he was inspired to convert the resources of the cotton mill he inherited to the manufacture of his 1956 ‘geotextile’ invention called Netlon. This utilised up-and-coming plastics technology to make strong netting that provided an easy, cost-effective solution for both commercial and domestic activities. For example, building contractors use it for soil retention alongside motorways while gardeners protect their plants and ponds with it.

Mercer continued to experiment and in 1978 invented Tensar geogrids, the rigid version of Netlon. Having the high tensile strength of steel, this has a vast range of applications in solidifying the ground for railways, roads, pavements, housing estates, stadia, runways, warehouses and office blocks, to name a few. The aggregate is pressed into the spaces of the grid and locks together, making it even stronger.

The Tensar company is still based in Blackburn today. It produces systems for any situation where stabilisation of a weak or uneven ground is required, including coastal locations subject to erosion. Mercer’s ingenuity, reflected in the hundreds of patents registered in his name, was rewarded with an OBE in 1981, among many other honours.

(Image: Robin Stott at geograph.org.uk / CC BY-SA 2.0)