RUBBER TREES

The tyre was first invented and patented by RW Thomson. He patented the Pneumatic Tyre in 1845. His first design used a number of thin inflated tubes inside a leather cover. This design actually had its advantages over later designs. It would take more than one puncture to deflate the whole tyre, and varying the pressures could alter the ride conditions.

It was not until the late nineteenth century, 1888, that John Boyd Dunlop invented the Rubber Pneumatic Tyre. Despite these technological breakthroughs the solid rubber tyre continued to be the dominant tyre and it was not until 1889 that the pneumatic tyre caught on.

In 1888, Scottish-born John Boyd Dunlop, a prosperous Veterinary Surgeon in practice in Belfast, Ireland, invented the Pneumatic Bicycle Tyre. A group of Irish businessmen from Dublin, realised the potential of the tyre, and, in 1889, together with Mr. Dunlop, formed a syndicate to float what was to become "THE DUNLOP PNEUMATIC TYRE COMPANY."

Most latex plants come from the New World. Latex is a mixture of compounds borne in special structures called laticifers. The composition differs in different species, but typically contains water, terpenes, sugars, enzymes, etc. In many plants latex has a milky appearance, but not in others. (Latex in latex paint is a synthetic material and is not related to true latex).

The properties of latex were apparently discovered by different groups of people in different areas. The Aztecs of Mexico played ball with balls made of latex of Castilla elastica (Moraceae). In the Amazon area, the Indians waterproofed clothing by coating it with latex of Hevea brasiliensis (Euphorbiaceae). The Spanish in South America also began to use it to waterproof clothing.

In 1823, Charles Macintosh discovered that rubber was soluble in hexane. Further, when the solution was applied to clothing, a thin layer was left on the clothes. He invented the "Macintosh" (a raincoat -- not a computer). [(or apple)]. In cold weather, they cracked. In hot weather, two people with Macintoshes often became inseparable. The coats stuck together.

In 1839, Charles Goodyear (whose wife allegedly nagged him) while working in his garage (that's why he worked in the garage) discovered how to vulcanize (no relation to Spock) rubber and make it non-sticky and much more usable. In this process, because of added sulfur, the rubber becomes cross linked and also has better elasticity.

Whenever people tried to raise rubber trees in South America, the plants were attacked by a fungal disease. In 1876, Sir Henry Wickham took seeds of rubber trees from Brazil to the Royal Botanical Gardens in Kew, near London. They were taken from there to Singapore and then to other places in Southeast Asia. Luckily, the fungal disease was not taken along with the plants.

Rubber was extracted mostly from wild trees of Hevea brasiliensis until the 1890's. The latex was collected (often in leaves) by slashing the trees diagonally. The latex is about 30% rubber and the rest is serum. When the latex was collected, it was filtered, mixed with water and slowly poured over a paddle held over a smoky fire. A ball of coagulated latex was eventually prepared. Rubber is still prepared in Brazil in this manner. Today, however, dilute acetic or formic acid is added to coagulate the rubber (especially in Asia) and the rubber rolled into sheets.

In Asia, cultivation of the plant is much more carefully done. The plant is grown on extensive plantations. Numerous breeding programs are in progress. The "jebong" method of tapping the trees gives better yields and is less harmful to the trees.

As rubber began to be used in pneumatic tires, about 1900, there was a rubber boom. In 1910, rubber sold for $3.10 per pound. Towns, such as Manaus in Brazil, did well economically. They even had an opera house and European opera companies came there (many of them got malaria and died). But at just about that time, the production of rubber plantations in Southeast Asia became important and the price went down. In the 1920's rubber went to 14 cents per pound and in 1932, it sold for 3 cents per pound. By World War II, 90% of all rubber came from Asian plantations.

Because of the war, much work on synthetic substitutes began. (The Germans had already made some synthetic rubbers). Several types of synthetic rubbers were made. For some purposes they are better than natural rubber, but, for others, not as good. In any case, use of natural rubber is greater today than at any time in the past. About 2/3 of all rubber goes into tires. Natural rubber is the best for airplane tires and is also important in radial tires.

Synthetic rubber is made from petroleum derivatives, which will be problem in the future as oil reserves run dry.

Hevea brasiliensis is a tropical tree. It is native to the Amazon Basin in Brazil and adjoining countries. In comparison to the production of synthetic rubbers from petroleum, Hevea, the rubber-tree, has been called "The green rubber factory". On the one hand, Hevea uses the sun as a renewable energy source together with atmospheric CO2, water and mineral elements of relatively poor soils for the building of its constituents. The by-products of Hevea are to a high degree "biodegradable" and rubber itself is "recyclable". The rubber tree may be used to reconstitute new forests on poor or degraded soils. Also, the wood from "the rubber tree" is increasingly used as timber.

Tapping begins once trees reach maturity at about seven years, although this may be later in unfavorable areas. Tapping involves periodically cutting bark on the trunk, and hence severing latex vessels. It is best done at a 25-30° angle from the horizontal, from high on the left of the tree to low on its right, in an action exposing the maximum number of latex vessels per length of incision. Tapping productivity is a critical issue in maintaining sustainable supplies of natural rubber.

The first pneumatic bicycle tyres to reach Australia arrived in Melbourne in 1889, and within 2 years, the Dunlop Company was established in Europe & North America ( the first pneumatic bicycle tyres to reach North America arrived in New York on Christmas Day, 1890).

In 1893, the Dublin Company opened a Branch Office and Factory in Melbourne, Australia, right in the heart of Melbourne's Chinatown district.

Since the bicycle was the popular form of transport, and Cycle Racing the most popular sport, the introduction of the pneumatic tyre was an unqualified success. In spite of this, the Dunlop Company ran into financial difficulties and decided to sell its overseas holdings.

In 1899, a Canadian syndicate purchased the Australasian interests and floated "THE DUNLOP PNEUMATIC TYRE COMPANY OF AUSTRALASIA LTD as an Australian company, with a capital of 170, 000 Pounds ( $A 340, 000).

In 1905, the Company made the first of its many acquisitions with the purchase of its main rival the Barnet Glass Rubber Company.

In 1889, John Boyd Dunlop founded the Pneumatic Tyre Company and Booth's Cycle Agency, which were to become the Dunlop Rubber Company Limited.

The company became involved in aviation in 1910, when Dunlop Rubber Company introduced a wire-spoked wheel with a beaded tyre specifically designed for the aviation market.

Dunlop was a Scottish vet living in Belfast. His son Johnny complained that when he rode his bicycle to school the cobbled streets made his bottom sore. Dunlop solved his son's problem by inventing a pneumatic tyre, but then it became clear that this tyre was faster - the lad kept winning cycle races. There was a famous cycle race on the Queen's College playing fields on 18 May 1889 and Dunlop persuaded the cycle champion Willie Hume to use the new tyres. Willie won the race and everybody wanted the tyres, and so the Dunlop Rubber Company was formed.

What Dunlop did not realise was that 43 years earlier another Scot had patented almost the same thing. Robert Thomson, who had been to America, returned to Britain and was given a workshop by his father where he invented all sorts of things. In 1845 Thomson patented what he called aerial wheels. There were no bicycles then, so it would not have been a bicycle tyre that he invented. There were no internal combustion engines either, just a few steam carriages, and otherwise horse-drawn carriages and carts. However, Thomson did some elegant experiments.

He fitted his tyres to a carriage and, in Regent's Park in London, had it pulled side by side with an ordinary carriage. He showed it was much easier to pull the one with pneumatic tyres. All the watching journalists thought it would be slower because the tyres were soft. It was easier to pull and also silent - it did not make the noise of a carriage. The pneumatic tyres were a huge success but there was no market at the time - rubber was very expensive in the 1840s.

Robert Thomson is much under-rated. He invented a whole range of things including a fountain pen - possibly the first fountain pen, though there are other claimants. He never became rich and famous, perhaps because he was so far ahead of his time.

Dunlop first advertised his tyres in December 1888 in The Irish Cyclist, and in May of the following year the Tyre had its first breakthrough. A Belfast Cycle Race was won on pneumatic rubber tyres, and by now the public were starting to take note.

Unfortunately the original tyre had its drawbacks. The inner tube was difficult to get at because the tyre was stuck to the wheel. In 1890 CK Welsh patented the design of a wheel rim and outer cover with inextensible lip. By now we had the basics for today’s tyre.