Latex (material)

Collect latex of hévéa

The latex is collected by light bleedings on the peripheral bark of the Hévéa. The slaughterers approximately carve a light from top to bottom notch on 10 centimetres in height and 1 millimetre of depth. Each year, they change side, during eleven years. One lets the tree then rest during at least a year. The tree can produce latex starting from the 7 years age and approximately 30 years.

The production of the year is distributed for approximately 40% in the 1st six-month period and 60% with the second half-year because of a Hivernage which reduces the production.

At the conclusion of its period of exploitation, the hévéa is cut down to be replanted. Progress of research makes it possible to carry out these replantings with a vegetable material much more powerful.

The latex, while leaving the notch, dries partially, forming the “coagulum” which is collected at the end of 4 minimum days. The notch heals naturally and one lets the tree rest during a few days before bleeding it again. As of the 19th century one sought to control coagulation. In 1929, one in particular noted that the natural Polymérisation could be started by Bactérie S

One finds also a latex in the Bananier S and of many other plants, but only that of Hévéa has desired industrial qualities.

Production zones

The principal production zones are the Southeast Asia (the Malaysia is the third world producer with 1,2 million tons in 2006 behind the Indonesia and the Thailand). Then the Ivory Coast and the Brésil come.

The plantations are fewer in Brazil because it prevails there a Champignon, the Microcyclus , which attacks the young sheets of less than ten days and destroys them. When the old sheets fall, the tree is deprived of young sheets; deprived of chlorophyllian synthesis, he dies. This mushroom, which must adapt to the characteristic of each tree, prevails primarily in the plantations and little in the nature in which the trees are disseminated too much.

Characteristics of the gross product

The latex is a product irremplaceble for many uses, because of its characteristics:

it is sticking (as long as it is not vulcanized)
it is rebounding
it stretches almost at will
it is flexible
it is very resistant

Latex with rubber

The coagulum are washed, shredded and rehabilitated in heated pellets with approximately 120°. To cooling, the pellets are stuck between them and are compacted to give balls which one sells and exports. The balls will have passed in a kind of Laminoir called " cylindres" or " mixer ouvert".

Uses of the end product

Uses in transport

The rubber without Soufre not vulcanized is breaking cold (winter) and poisseux with the heat (be). In fact the sulfur atoms, after vulcanization, weld the long chains of latex and thus ensure the elastic effect of rubber in a broader beach of temperatures.

90% of the production of natural latex are used with the production as Pneu S, charged out of lampblack. The tires made out of natural latex are more resistant to the tear than those done with artificial rubber and are used for the tires as planes.

Medical uses, vestimentary

Its elasticity makes of it a material very appreciated in the medical field and the everyday life (gloves, tétines for baby, glasses of ski, costumes grinding, etc). Certain people present a Allergie to latex. In certain cases, that can go until the Choc anaphylactic (severe allergic reaction).

The combinations are used for to be protected from the cold, in particular for the plunger . The fetishistic which make a sexual fixing on latex call the rubberists . By compressing the body, a latex clothing adjusted cut the Breathing by the skin and the directions, plunging its tenant in a kind of cocoon.

Uses with the cinema

The latex is also used as skin in the special Effets in Animatronique.

Uses out of staff

The latex is used in Staff to build low-size moulds.

See too

External bonds

August 1st

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