Natural rubber plantation

Following the Japanese blockade of exports from the natural rubber plantations of Malaysia, the United States established the Rubber Reserve Program, a crash program... 

Natural rubber can be obtained from the sap of a number of plants and trees, the most common source is the Hevea brasiliensis tree. Although natural rubber was known in Central and South America before the arrival of Christopher Columbus in 1492, the first use as an adhesive was established in a patent dated in 1891. As rubber became an important part of the industrial revolution, the rubber adhesives market grew in importance. To comply with the increasing demand on natural rubber materials, plantations of Hevea brasiliensis trees were established in southeast Asia in the early 20th Century, mainly to supply the demand from the automobile industry. 

In solid form, the natural rubber is graded according to the content of dirt remaining from the precipitation of latex at the plantation. Eight basic NR types have been traditionally recognized internationally. Only the so-called ribbed smoked sheets and the pale crepes are normally used for adhesives. The predominant grade system, the Standard Malaysian Rubber system, has been used since 1965. 

Natural rubber is obtained from the bark of the rubber tree, Hevea brasiliensis, grown on enormous plantations in Southeast Asia. 

The rabber industry changed again when the Japanese captured the East Indian rubber plantations during World War n. The resulting shortage of rabber prompted an intensive research program to produce synthetic rubber. Today, more than 2 million tons of synthetic rabber is produced each year in the United States. Natural rubber is still produced in the tropics, but its importance pales compared to the glory days of the Brazilian rabber plantations. 

Neoprene, Carothers first practical invention, was made reluctantly, as a kind of side issue to his scientific investigation of polymers. Synthetic rubber was of great commercial interest. The car-happy United States used half the world s natural rubber, and demand had outstripped the supply from wild rubber trees in the Amazon. Price fluctuations on British rubber plantations in Southeast Asia provided further incentive for the development of synthetic substitutes. Du Pont had been trying without success to... 

A process for separating particles from a suspension by using centrifugal force. It is the most popular method for concentrating natural rubber latex before shipment from plantation to country of use. 

Natural rubber to which has been added on the plantation a quantity of a peptising agent. Such pre-softened and easily-softened rubbers... 

Natural rubber obtained from cultivated trees as opposed to that obtained from trees growing wild in the jungle. The size of a plantation varies from the large estate of several thousand acres down to the smallholdings of a few acres worked by the owner and his family. Such smallholdings produce a significant proportion of the world s NR output. 

Natural rubber obtained from trees growing wild and not cultivated in either plantations or native small holdings. The output of wild rubber is now insignificant. 

Natural rubber can be found as a colloidal emulsion in a white, milky fluid called latex and is widely distributed in the plant kingdom. The Indians called it wood tears. It was not until 1770 that Joseph Priestly suggested the word rubber for the substance, since by rubbing on paper it could be used to erase pencil marks, instead of the previously used bread crumbs. At one time 98% of the world s natural rubber came from a tree, Hevea brasiliensis, native to the Amazon Basin of Brazil which grows to the height of 120 ft. Today most natural rubber is produced on plantations in Malaysia, Indonesia, Singapore, Thailand, and Sri Lanka. Other rubber-bearing plants... 

Polymer with the cis stereochemistry, which is obtained primarily from the Hevea brastliensis tree, is called natural rubber. Hevea originated in Brazil, from where several thousand seedlings were taken in the late 19th century and eventually transplanted in what was then Ceylon (now Sri Lanka). Today at least three-quarters of the world s natural rubber comes from plantations in Malaysia, Indonesia, Thailand, and Sri Lanka. The name rubber is attributed to Joseph Priestley, the British chemist well known for discovering oxygen. He called the material India rubber because it came... 

On a global scale, success of rubber plantations in diverse areas such as Malaysia and southern Brazil have drastically altered the price of natural rubber, making extractive rubber production less lucrative... 

For example, all these factors have operated in Amazon. Even during the rubber boom of the late 19 th Century colonization was primarily confined to locations on the riverbank which could be reached by boat. It was calculated that completion in 1912 of the Madeira-Mamore railway line of 364 km cost one life for every sleeper laid (de Oliveira, 1983). We now know much more about tropical diseases, but the problems are far from being solved (da Costa Linhares, 1983). Failure in exploitation may be due to unexpected reasons. The well-funded rubber plantation of the Ford Motor Co. (Fordlandia) established near Santarem in the 30 s failed by 1944 primarily because of fungus disease and an insect parasite. This was not a problem with the isolated trees of natural rubber in the jungle, but under plantation conditions the trees were close enough together for the infection to pass from one to another. At that time no effective pesticide treatment was available. 

Natural rubber is obtained from iatex that oozes from cuts made to the bark of the rubber tree. Waterproof iatex is the rubber tree s naturai protection, exuded in response to an injury. Although rubber was produced exclusively in Brazil until the late 1800s, today most of the world s rubber comes from plantations in Southeast Asia, Sri Lanka, and Indonesia... 

Just as in the manufacture of sheet natural rubber and the asphaltic sheet linings, the basic material as the sheet lining manufacturer receives it from the plantation (rubber) or from the refiner or importer (asphalt), the manufacturer of the synthetic lining materials will receive his synthetic elastomer, thermoplastic or other basic resin from the company that produces it-and will have to blend it with fillers, stabilizers, plasticizers, and other materials to make a suitable compound which will-as a lining—perform its function satisfactorily under the anticipated conditions, and for an economical length of time. The actual amount of the basic resinous material in the compound may be as low as 70% of the total weight. 

Natural rubber is obtained from the juice present in various trees and shrubs which grow best in tropical countries. On account of the importance of rubber commercially the trees which yield it are grown systematically on plantations formerly the supply was obtained from natural forests. The intensive cultivation of rubber trees has had a marked effect in lowering the price and insuring a steady supply of rubber. 

A.K. Krishnakumar, C.Gupta, R.R.Sinha, M.RSethuraj, S.N.Potty, T. Happen, and K. Das, Ecological impact of rubber (Hevea brasiliensis) plantations in North East India 2. Soil properties and biomass recycling, Indian Journal of Natural Rubber Research, 4(2), 131-141,1991. 

Natural rubber (NR) is one of natural polymers produced by a number of tropical countries Indonesia, Malaysia, Thailand, Sri Lanka etc. Indonesia, with about 2.6 Million Ha of rubber plantation, producing about 1.3 Million tonnes of NR annually. It was a subject of investigation long before the second WW,from the process of producing a raw NR which should meet a standard of quality to the process of producing rubber goods. 

Materials High ammonia type centrifuged natural rubber latex from Pasir Waringin Rubber Plantation. FTP XI, West Jawa, lndone.sia was used (Table 1). Carbon tetrachloride and normal butil acrylate were used as sensitizer. Nocract 300 was used as antioxidant. All the chemicals were technical grade without further purification. 

Table 1. Specification of natural rubber latex from Cikumpai rubber plantation, produced in September, 1989.

All other industrial coimtries remained content with natural rubber. Its qualities were still better overall. However, all was to change during the Second World War, when almost all the rubber plantations in South-Eastern Asia were occupied by the Japanese. This encouraged the search for new methods of synthesizing rubber, especially in the United States and Canada. Soon, the world production of artificial rubber caught up with and, by the 1960s, had surpassed the production of natural rubber. 

In Southeast Asia the ambitious expansions of oil palm plantations in the tropical areas have made this region by far the main palm oil producing region in the world outdistancing natural rubber cultivation as the key agro resource in Malaysia (Figure 9.1.4). 

We begin with two trees, both cultivated on plantations in Southeast Asia. One, Hevea brasiliensis, is a source of natural rubber and was innported from Brazil in the nineteenth century. The other, Isonandra gutta, is native to Sumatra, Java, and Borneo and gives a latex from which gutta-percha is obtained. 

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