Happy Anniversary!

As Perspex celebrates its 75th anniversary, we trace the history of this iconic brand and discover that its original purpose was as far away from signage as you could possibly imagine!

In 1934, the word Perspex came into the English language for the first time. Derived from the Latin ‘to see through’, it was registered as the trademark for ICI’s acrylic sheet and is now regularly used, both figuratively and literally, to describe the many different clear plastic products available.

Perspex came about as a result of an independent general study of polymeric materials and a simultaneous project to find a laminated safety glass interlayer. In the first instance, John Crawford of the ICI Research Department was looking for a replacement for cellulose nitrate, which yellowed badly when exposed to sunlight, whilst, at the same time, Crawford Hill of British Dyestuffs Corporation created a methyl methacrylate polymer, which turned out to be unexpectedly hard and tough. A patent was applied for in November 1931, which also covered both the moulding and extrusion of the polymer.

Both Hill and Crawford recognised the unique properties of the material, but also had to ensure that its manufacture was economically viable, before commercial production was possible. Crawford’s vital contribution was to determine the reactions involved and the conditions necessary to achieve an optimum yield. This work resulted in a process that produced 100lb batches of methyl methacrylate monomer, a commercially attractive quantity. Produced in Billingham at the Cassel Works, the monomer was cast between flat sheets of glass, separated by a gasket and polymerised in an oven. This still forms the basis for the commercial manufacture of acrylic throughout the world, although nowadays, the process is more stable, produces larger volume and greater emphasis is placed on quality control.

Originally offered as a lighter weight alternative for safety glass, Perspex production really took off during the war, when it was used as a glazing material for aircraft. With demand increasing the Ministry of Supply insisted that Perspex was manufactured over a number of different sites, to minimise the risk from enemy attack. In 1940 a new production site was thus established in Darwen, Lancashire, where production still continues to this day as, according to Mike Lombard, Technical Support Manager at Lucite International, it has more low-lying cloud cover than any other UK town!

The fledgling product soon became an increasingly important part of the war effort, with 50 tons of Perspex being produced during the first year of manufacturing at Darwen. Used for the cockpit canopies of fighter aircraft, Perspex production increased significantly during the Battle of Britain year, reaching 455 tons and, by 1944, production had grown to six thousand tons. However, this use of the product was always going to be of a temporary nature and, as expected, with the end of hostilities, the demand for Perspex fell dramatically to less than half that of its wartime peak. However, some succession planning for the product had already been considered and a corrugated Perspex sheet was produced to provide natural daylight in industrial and agricultural buildings. Favourable reports on its performance in this capacity meant that it became a huge success, although it took much longer for Perspex flat sheet, in clear and colours, to find a proper replacement market.

One of the new colours developed at Darwen was opal, which was produced in four different grades, thus helping to fuel a demand in an entirely new market sector, that of indoor and outdoor lighting applications. The lighting sector’s endorsement of Perspex was encouraged by the installation of four hundred fittings designed by Sir Gilbert Scott for the new House of Commons. This success and the abundance of grades and colours subsequently lead to Perspex being used for signs and fascias. Complemented in no small part by the characteristics of the material, such as excellent strength, rigidity and resistance to weathering, signage remains a prime Perspex market.

A versatile material, which can be used both inside and out, Perspex is noted for its unequalled clarity. Produced in a batch process, it can be made in many colours, surface textures and grades and is available in a vast range of standard products. Further, with an accumulated store of colour-match records, it has been used for many innovative sign applications and major corporate identity programmes.

One such project is the iconic Fort Dunlop sign, which is located just off the M6 at Birmingham. Noted for its landmark status, the sign was made from the latest Perspex Opal LED Light Source Grade. Produced by signmaker ASG, it features individual letters, each of which stands 2.5m high, and is 45 metres long. Paul Neal, Manager of Perspex Distribution’s Midlands branch says: “This spectacular sign, which is located at the summit of the Fort Dunlop building is made even more impressive by the incredible number and combination of colours that can be produced, thanks to the brilliant and even illumination properties of the specially developed Perspex surface”.

Now, 75 years after it first appeared, Perspex is produced in many variants. Since 2003 it has been supplied in the UK by Perspex Distribution, who has once again established Perspex cast acrylic as a market leader. Undoubtedly, the UK’s foremost plastic and a nationally ubiquitous brand, Perspex shows no sign of dropping out of vogue and although its name will continue to be used to describe for all manner of clear plastic products, there is only one Perspex!

For further information visit: www.perspex.co.uk

Top of page