Gutta percha (GP), also known as balata, is a natural thermoplastic and is of fundamental importance in the history of the plastics industry.
This new material was soon adopted by a vigorous innovative society and by the time of the Great Exhibition in 1851 a host of different applications had been found covering many aspects of Victorian life. The major use of GP was for the insulation of submarine cables which revolutionised communications throughout the world. By the end of the nineteenth century over a quarter of a million nautical miles of telegraph cable was in use. This application was to continue for a total of 100 years until polythene took its place. A revolution of a different kind resulted from the introduction of GP for golf balls in 1848. Until then feathers encased in leather was used which was very expensive and quickly became unplayable in wet weather. Balls made of solid GP had no such disadvantages and their cheapness and reliable performance was a major influence in the vast expansion of the game in subsequent years.
Another innovation, which must have been greeted with more than usual enthusiasm at a time before aspirin, was the development, also in 1848, of a dental stopping compound which is the forerunner of all temporary filling materials in use today. These are but three of the hundreds of applications which were developed in the first decade. Although GP has been superseded by modern synthetic materials it still has its uses. The raw material is now supplied from America (as balata) where it continues to be used for golf ball covers. Belting incorporating balata is used for power transmission, GP tissue is sold for binding flower stems and even dentists continue to use it for root filling. The excellent moulding properties of GP are still exploited for making replicas of medals and coins and, coloured red, for seals on official documents in Scotland. The importance of GP is now much diminished but its position as the first plastics material remains secure.
In more detail:
Gutta percha was obtained from a variety of guttiferous trees throughout the Pacific Rim although different varieties produce materials of differing quality. The differences generally reflect the quantity of resin in the product with that from Pahang having the lowest resin content. Balata has one of the highest resin contents and was obtained from trees in the tropical regions of South America.
There is much confusion in the literature, and amongst collectors, as to “what gutta percha is”. In practical terms, and when addressing collectors’ items, the material is probably the whole residue from the latex, dried after collection from whichever tree was its source. This material tends to range from dark yellow through red to black. It is possible that it has undergone some degree of purification but, given the variations in initial composition, it would be extremely difficult to confirm this, even by detailed chemical analysis.
In the same way that commercially available natural rubber is some 95% cis polyisoprene, the crude gutta percha was often 30% to 50% trans polyisoprene. That is it has the same chemical “building block” as natural rubber (C5H8)n but with a different spacial configuration. Isolation of the pure trans polyisoprene gives a white/very pale cream “cheesy” material which looks and feels not unlike a block of high density polythene (m.p. about 135°C) or polypropylene (m.p. 168°C). The hard gutta percha softens at relatively low temperatures (>71°C) and could then easily be moulded or extruded (the screw extruder was invented in 1845). At slightly lower temperatures, around 60°C, it can easily be cut whilst at room temperature it reverts to a hard material.
It is generally believed that a British surgeon, Dr. William Montgomerie, was the first person to introduce the Western world to gutta percha in 1843. However, that honour actually belongs to John Tradescant who had returned from his travels in the Far East with this material in 1656. He called it “mazer wood” but it then was regarded as only one of many plant curiosities and it was left to Dr Montgomerie to appreciate its potential. He originally saw the material in Singapore, in 1822, and learned its Malay name – gutta percha – but he forgot about it when he transferred to the Bengal Residency. When he returned to Singapore he remembered the material and how the workers had made handles for their machetes with it. It struck him that there was potential for its use both as knife handles and for various medical devices. After some experimentation he referred his work (in 1843) to the Medical Board of Calcutta and copied the documents to The Royal Society of Arts in London through his brother-in-law. The Society realised the potential of the material and promptly awarded Montgomerie its gold medal. At about the same time, Dr Hosé d’Almeida submitted similar studies to the Royal Asiatic Society together with some samples of gutta percha. Early experiments in England with the gutta were not very successful but in Paris, using Montgomerie’s data, several medical instruments were manufactured.
Once the technology was understood, things moved rapidly and later that year Hancock& Bewley formed The Gutta Percha Company in the UK. In 1845 Lagrénée returned to France from China and brought with him some gutta percha which he too had found in Singapore. His named the material “gum plastic”. In the following year we can record the first gutta percha patent – taken out by Alexander, Cabriol & Duclos for a laminate consisting of three layers: gutta-fabric-gutta. Unfortunately they considered gutta to be akin to rubber and overlooked the fact that its plastic qualities were quite different from the elastic properties of the latter. As with the early days of rubber, it looked as though gutta percha was not going to be of much use.
However, Gutta percha had properties which could be exploited and three of these, together with its softening at easily attainable temperatures, provided its three main areas of use until each was superseded by advances in synthetic plastic materials.
The three properties were its hard “plasticity”, its electrical insulating properties and its extremely low coefficient of thermal expansion/contraction. These were exploited in quite different ways; the first in the manufacture of golf balls, the second in the manufacture of telegraph cables and the third in the making of moulds, dies and castings where the final (cold) product was dimensionally identical to the moulded (hot) one. This last area was of considerable importance because of the extreme delicacy and detail which could be included in the mould and then copied by the new “electro-metallurgical” process.
The first gutta percha golf ball, known as a “gutty” was hand moulded by J Patterson in Scotland in 1845 and was just a smooth ball. Previous balls had been made of wood, then leather stuffed with feathers and these took a couple of hours or so to make. The rapid introduction of metal moulds meant that one person could turn out 10 or more per hour which drastically reduced their cost and was a significant factor in the expansion of the game’s popularity. In the 1860’s it was discovered that cutting groves in the ball improved its flight. Again, this was originally done by hand but by the 1890’s the pattern was built into the moulds. Early in the 1900’s a new ball was introduced which had a core of stretched natural rubber thread and the era of the gutty was over. In 1845 W Siemans suggested gutta percha as telegraph wire insulant and two years later WH Barlow & T Forster took out a UK Patent for the making of telegraph cables with gutta percha. In the same year JJ Craven, working in the UK, insulated undersea cables with gutta percha and in 1849 R & J Dick gave us the first recorded use of gutta percha as a telegraph cable insulant (in London). The following year they founded R & J Dick Ltd. Gutta Percha and Balata Manufacturers.
At the same time, J and JW Brett were preparing to lay the first gutta percha insulated cable from Dover to Calais. In 1850 they made their first attempt, which failed, as did their second the following year. However, they were able to repair this and so began a new era of communication. In 1858 CW Field used the ship “The Faraday” to lay the first transatlantic telegraph cable. This was both insulated and coated with gutta percha.
Gutta percha is very stable underwater and the cables lasted many years – it would not surprise me if some still existed today although modern ones are plastic insulated and coated. Indeed, Gutta percha is very difficult to find today in anything other than antiques. A recent television programme about the history of golf found its researchers scouring the country to find some virgin material. One small sealed tin was eventually found in Hertfordshire and, when opened, it revealed a slab of pale cream pure gutta percha which had not seen the light of day for many decades. After filming the tin was re-sealed for posterity.
Gutta Percha admin 2016-12-06T05:35:22+00:00