Notes
These 4 'Marquis' Bakelite plastic Mugs were made by Commonwealth Moulding Company Pty Ltd, in Australia from the period of 1925 to 1935.
The 1943 Australasian Manufacturers Directory lists Commonwealth Moulding Pty Ltd as operating from 242 Princes Highway, Arncliffe, New South Wales, Australia. The company is listed as producing such wares as aircraft parts, electrical appliances and parts, jewellery, furniture and interior decorations, household and kitchen appliances, industrial equipment, and optical equipment (Plastics Institute of Australia 1947).
Phenolic plastics, also known by popular names such as 'Bakelite' and 'Nestorite', are valued for their excellent heat resistance and low electrical conductivity. The scientific achievement underpinning the product is predominantly associated with the work of Leo Hendrik Baekeland (1863-1944), a Belgian-American industrial chemist, who reacted (condensed) phenol and formaldehyde to form a resin that hardened upon cooling and which, when moulded, had excellent mechanical and electrical properties (Cook 1992). Phenol-formaldehydes were the principle plastics manufactured in Australia at this time, using locally manufactured raw materials (Penfold 1946). The development of urea-formaldehyde allowed for the production of brightly coloured plastics, also displaying excellent heat resistance.
Phenol and urea-formaldehydes are known as 'thermosetting plastics', being distinct from 'thermoplastics' which soften on heating and harden on cooling, with this process able to be repeated as often as may be required. Penfold wrote that: 'Thermosetting plastics...can be prepared in a form in which they are initially thermoplastics, in which condition they can be moulded under appropriate conditions of temperature and pressure; further heating at quite moderate temperatures (260-350F.) causes them to set permanently. They cannot again be softened by heating, but, being organic materials, they char at a temperature of about 650?F. (Penfold 1956)'
References:
Penfold, A. R., 'The Story of Plastics', in Sydney Technological Museum News Bulletin, Sydney, No 8, 1943, p11
Penfold, A. R., 'Reports on Plastics Investigation, 1945 in the United States of America, Canada and the United Kingdom', Thomas Henry Tennant, Government Printer, Sydney, 1946, p3
Penfold, A. R., 'Plastics and Synthetic Fibres', A.H. Pettifer, Government Printer, Sydney, 1956, p9
Plastics Institute of Australia, 'Australian Plastics Trade Directory', Sydney, 1947