The encyclopedia · Engineering & Operations · Technical decision · 1869–1872
Hyatt plasticised nitrocellulose with camphor to replace ivory
John Wesley Hyatt used camphor to make nitrocellulose mouldable, turning a brittle explosive look-alike into the first plastic.
John Wesley Hyatt
the move
In the 1860s a billiard ball was made of ivory, and ivory came from elephants. It was scarce, expensive, and the supply could not keep up with the demand for the game. John Wesley Hyatt, an American inventor, set himself the problem of making a billiard ball from something other than ivory. He tried mixtures of cloth, ivory dust and shellac, then patented in 1869 the use of collodion for coating billiard balls.
His work was on cellulose nitrate, a material made from cotton treated with acid. It could look a little like horn or ivory but on its own it was hard, brittle and hard to shape, and it was also flammable and hazardous to make. The material alone was not going to replace ivory.
The breakthrough came when Hyatt and his brother Isaiah recognised the value of camphor as a plasticiser for cellulose nitrate. Camphor, a very small molecule, softens and flexibilises the stiff polymer, letting it be heated and moulded into smooth, horn-like forms. This is what turned a brittle laboratory curiosity into a material that could actually be shaped into billiard balls, combs, collars and all manner of everyday items.
John Wesley Hyatt and his brother Isaiah took out U.S. patent 105,338 in 1870 for this process of producing a horn-like material using cellulose nitrate and camphor. In 1872 Isaiah Hyatt coined the term celluloid to describe the commercially successful product, and it became the first widely used plastic.
why it works
- Ivory was scarce, expensive and could not meet the demand for billiard balls.
- Cellulose nitrate alone was hard and brittle and could not be moulded into shape.
- Camphor acts as a plasticiser, softening and flexibilising the polymer so it can be shaped.
- The mouldable horn-like result could be dyed and worked like ivory but was produced from cheap cotton and acid.
what transfers
A material that is unusable because it is hard and brittle can become a product if you add a small molecule that loosens the structure and lets it be shaped.
what came after
Hyatt and his brother Isaiah took out U.S. patent 105,338 in 1870 for producing a horn-like material from cellulose nitrate and camphor, and in 1872 Isaiah Hyatt coined the term celluloid for the product. Celluloid became the first widely used plastic, appearing in billiard balls, combs, collars, cuffs and photographic film. It had real drawbacks — it was flammable and that caused later problems, including with early film — but it proved that a synthetic, mouldable material could stand in for a natural one, and it set the pattern for the plastics industry that followed.
references
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