Höxter, 29 June 2018. This slogan is very apt since rubber really does keep the world in motion. Although it operates out of sight, almost no complete industrial system would work without this material.
Cars, bicycles, buses, subways, trains – without rubber, they would all stand still. Quite apart from that, driving a car would be far less of a pleasure if engine vibrations and noise were not insulated with a damping engine mount and the driver got shaken around in the car. Leaking windows and rattling doors would do the rest.
The origin of rubber
Natural rubber is a resilient material obtained from the milky sap of various rubber plants, but from the rubber tree in particular. An incision is made in the bark, and the latex emanating from tubular lactiferous vessels in the tree is collected in receptacles.
The oldest known objects made of rubber originate from the time around 1600 BC. Even in the pre-Columbian era, civilisations such as the Maya used natural rubber in many ways. The Mesoamerican ball game originated around 1400 BC and was played with an all-rubber ball. Materials were coated with rubber due to its water-repellent properties. Hoses, vessels, torches and clothing were also made from this material.
It was the Maya, too, who gave the rubber tree with its milky sap the name “caoutchouc” by which it is also known: “Caa-o-chu“ means “weeping tree“.
After the discovery of America, rubber was known to only very few Europeans. In the mid-18th century, scientists observed how rubber was used in the Amazon region– based on processing methods that native Indians used. The material was barely fit for use. When it was very hot, it started to get sticky and when it was cold, it became brittle. UV radiation and weathering adversely affected rubber products and they quickly became unusable. In the age of industrialisation, new processes were developed, resulting in products such as the first rubber eraser in 1770 and the first raincoat in 1824, but this natural material was still far from easy to handle.
In 1839, Charles Goodyear invented the vulcanisation process – thereby transforming the malleable material into elastic rubber. This opened up entirely new uses which resulted in a wide variety of rubber products. Industry used it for gaskets in steam engines, for bicycle tyres and for insulating telegraph cables and, later still, for manufacturing car tyres and as insulation in the electrical industry. Rubber as a raw material became an extremely important commodity during the industrial revolution.
Today, rubber is used in extremely diverse forms, such as in
• Car tyres,
• Binders for paper surfaces,
• Carpet backs,
• Foam rubber,
• Sealing systems,
• Chewing gum.
While the numerous applications for rubber had to be opened up over a timescale spanning millennia, today’s producers of rubber applications are faced with new challenges. Important aspects for future rubber developments are better resistance to substances and temperatures, since products in automotive and industrial applications, in particular, are required to withstand exacting and exceptional conditions. Other challenges to be met are an improved low-temperature flexibility in sealing applications. General aspects such as chemical and temperature resistance and flame retarding properties pose continuing challenges to industry. A current issue concerning rubber products looks at ways to recycle them.