05/31/2011

Rubber

Elastic polymers that are based on vegetable products (primarily latex) are known as (natural) rubber. Latex is mainly used to produce rubber by vulcanisation. The rubber tree is the most important source, accounting for about 90 per cent. To obtain rubber, a slanting cut is made in the bark of the rubber tree and the tree is tapped. The latex flows out of this cut into a container placed below it. A rubber tree is then tapped about 165 times a year on average.

The oldest known objects made from rubber go back to the time around 1 600 BC. As early as this, indigenous tribes in Central America were already using rubber to produce solid balls, hoses and containers as well as water-repellent coatings for fabrics. It was not until many years later that the modern, versatile material we call rubber was to be made from such a valuable raw material as this natural rubber. In 1839, Goodyear and Hancock – independently of each other – discovered a process known as Vulcanisation to make a material from rubber with the addition of sulphur that was not brittle when cold and did not soften when hot. Rubber – and thus what was to become the “heart” of the tyre – was born.

The most important countries that produce natural rubber nowadays include Thailand, Indonesia and Malaysia. They took over long ago from what used to be the rubber barons of North and South America, who enjoyed considerable prosperity for a time and then squandered their riches.

About 60 per cent of global demand for rubber is now covered by synthetic rubber that is produced petrochemically. In view of the depletion of oil reserves, the renewable alternative might soon regain its leading position, however.