What is rhodoid?

Answer 1

"Rhodoid" is a trade name for a cellulose acetate Plastic made by May & Baker Ltd, England.

Cellulosic plastics are based on cellulose, which is the principal structural component of plants. The first Cellulosic plastic was invented in 1852 by Alexander Parkes who developed cellulose nitrate into a mouldable dough he called Parkesine. By 1860 it was being pressed into moulds to make billiard balls, pens, and even artificial teeth.

One of the problems with cellulose nitrate was that it was a highly flammable material. Cellulose acetate solved this problem and was first prepared in 1864 . Cellulose acetate is made from wood or cotton fibres that are treated with acetic acid and acetic anhydride, then turned into a powder. It is then mixed with other chemicals to produce a plastic dough. The dough can then be made into sheets, rods or mixing powder. One of the first applications for cellulose acetate was as a safety film, used to coat the fabric wings of aeroplanes during the World War I. Modified cellulose acetate was patented as the first injection moulding compound, revolutionising the plastics fabrication process.

Between the wars, it was often used to make demonstration 'floppy' gramophone records, ones not designed to last any length of time.

May and Baker Ltd was first established in England in 1834. The company was started by John May, Joseph Pickett, and Thomas Grimwade and called 'Grimwade, May & Pickett'. By 1839 Pickett and Grimwade had left the business and John May was joined by chemist, William Baker. May and Baker were awarded a prize in the London 1851 exhibition for their pharmaceuticals. The company became May and Baker Limited in 1890 and still operated in 2007 producing pharmaceuticals.

Reference:

Plastics Historical Society [2006], cellulose acetate fact sheet [online], Available at: http://www.plastiquarian.com/ca.htm accessed March 2008.

Early Plastics- perspectives 1850-1950, edited by Susan Mossman, Leicester University press, London, 1997

May and Baker Company [2007], History of May and Baker [online], Available at: http://www.may-baker.com/, Accessed March 2008.