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Natural Rubber

Whilst we have synthetic or manmade rubber produced from petroleum, around one-quarter of the world's rubber comes from a natural source. Natural rubber is a vital agricultural product or commodity which is used in the manufacture of a wide range of products. Rubber plays a major role in the socio-economic fabric of many developing countries. Over 20 million families are dependent on rubber cultivation for their basic source of livelihood.

Source of natural rubber
The natural rubber is produced from hundreds of different plantspecies. However, the most important source is from a tropical treeknown as Hevea brasiliensis, which is native to the tropicalAmericas. This tree grows best in areas with an annual rainfall ofjust under 2000mm and at temperatures of 21-28 degrees. Due tothese features and the preferred altitude of the tree around 600metres, the prime growing area is around 10 degrees on either sideof the equator. However it is also cultivated further north inChina, Mexico, and Guatemala.

In 1876, Sir Henry Wickham collected some 70,000 seeds from Brazil.These seeds were germinated and shipped to the East Indies, wherethey began today's rubber plantations. Today Malaysia, Indonesia,and Thailand produces around 90% of the world's natual rubber. Newplantations have also been started in Africa, The Phillipines, andEurope to make up for insufficient rubber output in Indonesia.

Natural rubber industry
The natural rubber industry has developed during the last 100years, inspite of emergence of manmade rubber. The development ofthe industry has relied upon well-targeted research and developmentin various fields like agronomic science, breeding to raiseproductivity, and physics, chemistry and technology to support andexpand a growing plethora of applications.

Natural rubber products
Products made from natural rubber, like tyres, engineeringcomponents and latex products which are used in the battle againstAIDS and other disease are very essential to modern life. Naturalrubber is available in many grades. However, the most importantdistinction is that between latex and solid grades. Latex is theliquid which comes out of the tree. Solid grades are produced fromlatex which has coagulated either in a factory or in the field. Thenatural rubber latex products are wide and varied like gloves,balloons, tubes, condoms etc.

Properties of natural rubber
Natural rubber has certain unique properties such asfollows:
  • Natural rubber combines highstrength (tensile and tear) with outstanding resistance tofatigue.
  • It has excellent greenstrength and tack which means that it has the ability to stick toitself and to other materials which makes it easier tofabricate.
  • It has moderate resistance toenvironmental damage by heat, light and ozone which is one of itsdrawback.
  • The natural rubber hasexcellent adhesion to brass-plated steel cord, which is ideal inrubber tyres.
  • It has low hysteresis whichleads to low heat generation, and this in turn maintains new tyreservice integrity and extends retreadability.
  • The natural rubber has lowrolling resistance with enhanced fuel economy.
  • It has high resistance tocutting, chipping and tearing.
Uses of Natural rubber
  • Natural rubber forms anexcellent barrier to water.
  • This is possibly the bestbarrier against pathogens such as the AIDS virus (HIV). That is thereason why latex is used in in condoms and surgical and medicalexamination gloves.
  • Natural rubber is an excellentspring material.
  • Natural rubber latex is alsoused in catheters, balloons, medical tubes, elastic thread, andalso in some adhesives.
  • Other than rayon, it is thesole raw material, which is used by the automotive industry.
  • Rubberwood is anotherbyproduct of natural rubber which is growing in importance. It is asource of charcoal for local cooking.
Natural Rubber Consumption
It is seen in recent years that there has been a shift in therubber consumption patterns from North America and Western Europeto southern and eastern Asia. The major natural rubber producers(Malaysia, Thailand and Indonesia) have also become major rubberconsumers. There is also the potential for Eastern Europeancountries to increase its uptake of natural rubber. India, Chinaand Brazil consume all of the natural rubber produced within theircountries. Thailand is considered to be the world's largestproducer of NR, followed by Indonesia, Malaysia, India, China,Vietnam, Sri Lanka and a number of other countries. These countrieslie within a band lying from 5° to 15° north or south of theequator and hence suitable for NR production. As per a reportpublished in 2001, the world produces around 6.5 million tonnes ofNR each year.

 
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