Casein Plastics From Food to Plastic

Humans have utilized the milk protein casein as a food source since the domestication of livestock. The use of casein in non-food applications dates 

Casein-formaldehyde soon was being produced and utilized in numerous applications across Europe. By 1915 European manufacturers of casein had found a viable method of making high-quality casein plastic. Dry casein could be slightly moistened with water, then processed into a plastic by 

The development of casein in the USA proceeded more slowly than in Europe. It was not until 1919 that the first casein plastic that was up to European quality standards was made in the USA. Even then, the industry in the USA did not take off for several reasons climatic differences meant the European processes could not be copied in a straightforward manner in the USA, the long and costly process did not yield easily to faster processing in automatic machines, and the scrap could not be reworked, so 50% waste was not uncommon. All this made competition with established materials more difficult.  

In 1929, Christensen added aluminum stearate, a water-soluble aluminum salt, to the resin and found that a non-hardened plastic rigid enough to be worked in automatic machines was produced. This not only allowed the casein plastic to be worked in machines, but aluminum casein scraps were easily re-workable, greatly reducing waste. In 1926, 55% of the world s buttons were made of casein.  

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