Matières Premières > Rubber/Gum

Background Information
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What is Latex?

Latex is the protective fluid contained in tissue beneath the bark of the rubber tree, Hevea brasiliensis. In its purest form, latex is a milky white liquid composed of rubber particles dispersed in water that can be tapped from the trunks of mature rubber trees.

Latex contains hundreds of proteins, including enzymes that are involved in the biosynthesis of the rubber molecules.

Processing

Most natural rubber is produced in Africa and South Asia. Trees are tapped for latex, by cutting a spiral groove in the bark and placing a spout and collection cup, containing ammonia or some other preservative, at the bottom.

Initially, the rubber had to be solidified within 24 hours to stop bacterial spoilage, this was known as crepe, but in the 1920's it was discovered that the addition of ammonia could preserve the latex.

By centrifugation (rotating in order to separate liquids from solids by the action of centrifugal force) a concentrated product is obtained.

Additional chemicals, such as accelerators, and antioxidants are added for strength, stretch and durability.

Natural rubber is derived from latex, and should be distinguished from synthetic rubber, derived from petrochemicals.

History

Latex is believed to have originated more than a hundred years ago. The tree originated from Brazil (hence its name - Hevea brasiliensis), and latex was originally gathered from wild trees in the jungles of Brazil in the 1870's. By 1890, Britain had introduced rubber plantations in Malaysia (with the help of Kew gardens and the Singapore Botanical Gardens) and was harvesting latex.

Africa and Sudan now produces 60 per cent of the world production.

The African industry is overseen by UAGAP, the Union of African Gum Producing Countries whose members include Sudan, Chad, Niger and Nigeria. UAGAP aims include improved quality control methods including greater interaction with farmers and establishment of buffer stocks for periods of lean production such as droughts.

Nigeria produces the highest quality gums, such as Nigerian No 1, which are derived from wild trees. One of Nigeria’s major domestic players is Tadacon.

The largest buyer of gum in the first half of the century was the UK. There was a time when London was synonymous in the trade with gum product exports. Subsequently, France began using gums, then America.

Today, the US is the largest consumer of gum-based products, used mainly in foods.

The value of gum trade exports has shrunk since 1967 when a total of 40,000 tonnes of Arabic gum were exported, worth £40 million, while 4,000 tonnes of Karaya gum and 300 tonnes of Tragacanth gum were exported both worth £5 million.

This levelled out in the 1980’s and has remained constant ever since. By 1997 exports of Arabic gum total 25,000 tonnes worth £34 million with 3,000 tonnes (£4.5 million) and 150 tonnes (£2.5 million) for Karaya and Tragacanth gum respectively.

Types & Uses

Natural gums include Gum Arabic (Africa), Gum Karaya (India/Africa), Gum Acacia, Gum Tragacanth (Iran) and Gum Ghatti, which are used in the foods and pharmaceutical industries. Gums are used as emulsifiers and stabilisers.

Health Foods	Global demand for healthier food additives, including gums, has grown in recent years as the global food industry's use of fats in food declines. In particular, economic development in Asia and central America has resulted in massive demand for better processed food. Trends in the industry include the removal of fats, calories and sodium from foods and replacing them with nutritional ingredients. The rapid growth in the gums sector is being largely driven by consumer demand for low-fat and no-fat products. This means replacing oil with water and using thickeners to provide the same taste and texture normally supplied by fat.
Labelling	Paper and cloth, with users finding Gum Arabic much more economical than synthetic adhesives. One of the biggest advantages of the product is that, even after it hardens, it remains water-soluble. It is therefore ideal for use with fabric labels, which must come off at the time of tailoring.
Soft drinks	All soft drinks are made with Gum Arabic, which is an excellent stabiliser, is used for oil and water entrapment and has a good "mouth feel".
Chewing gum	Chewing gum is nothing but Gum Arabic, sugar and added flavours.
Fireworks	Used for binding fireworks

Characteristics

In low concentrations, these gums form a `solution'; in higher concentrations, a `slurry'; and at the top of the thickness scale, they form a `gel'.

The whiter varieties are more valuable, while the red and amber ones fetch a lesser price. The black ones are at the bottom of the scale.

Before it is processed, Gum Arabic comes in the form of lumps, crystals and a fine crystalline powder which goes through a mesh. The product has to be manually sorted out and segregated according to size, colour and purity.

Gum Arabic is soluble in water, Gum Karaya is not soluble in water.

What is the International Rubber Study Group (IRSG)

The IRSG was founded in 1944 to provide a forum for the discussion of matters affecting the supply of and demand for natural rubber; it covers all aspects of the world rubber industry, including the manufacture of products, trade in raw materials and products, shipping, marketing and distribution. It collects and disseminates statistical data and undertakes economic and statistical studies on specific aspects.

What is the Association of Natural Rubber Producing Countries (ANRPC)

The ANRPC was founded in 1970 to promote the overall interests of natural rubber; membership is open to the governments of countries producing natural rubber. Its objectives are to bring about co-ordination in production and marketing, to promote technical co-operation among its member countries, and to bring about remunerative and stable prices for natural rubber.

The ANRPC performs studies on the world rubber position, examines short- and long-term problems and promotes research and development. Its Secretariat is in Kuala Lumpur.

What is the International Natural Rubber Organization (INRO)

INRO was established in 1980 to operate the International Natural Rubber Agreement the main purpose of which is to stabilize the price of natural rubber by buying for and selling from a buffer stock. INRO's terms of reference also cover measures to improve the status of natural rubber by encouraging research and other activities. Its headquarters are in Kuala Lumpur. At a meeting in September 1999 the participating nations agreed to terminate the Agreement and to liquidate the buffer stock. This operation is now taking place.

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