How is rubber made?

Answer 1

The manufacture of rubber begins with the rubber tree, botanical name hevea brasiliensis. Originally from Brazil, specimens were moved to Malaya (now part of Malaysia) and Burma (now Myanmar) where large plantations were established in the nineteenth century. The tree is tapped by making a shallow v-shaped slit in the bark; a spout is inserted at the bottom of the V and the sap of the tree is collected.This sap, called latex, may be shipped out after cleaning for making certain types of rubber products. Most latex is poured into large flat trays to be dried over a wood fire on the plantation. The resulting solid sheets are then passed through a mill fitted with ribbed rollers, which form corrugations on the sheets about a centimeter apart. The result of this is a product known in the rubber trade as ribbed smoked sheets (always abbreviated to RSS). RSS is then pressed into bales of around 100Kg; it is the same colour as a smoked herring (aka kipper) and smells like one too. The bales are shipped all over the world for processing. The next step in making a finished rubber product is to masticate the RSS. This is done on a calender mill, where the raw rubber is fed between two rollers that are slightly separated from each other and turn at slightly different speeds. Various other ingredients are then fed in. These usually include a filler (which is mostly either soot or china clay), one or more lubricants and, finally, a vulcanising agent. This last is usually powdered Sulphur, although some usable organic compounds are known. When all ingredients are well mixed uncured components are formed, either in moulds or by extrusion. They are then heated; this heating carries out the process of vulcanisation, in which the sulphur causes the formation of cross-links between rubber molecules. These links greatly improve the mechanical properties of the final rubber product over a range of temperatures, especially preventing the rubber from being brittle when cold or sticky when warm.

Natural rubber comes from the bark of the Hevea Brasiliensis tree that grows in Southeast Asia. To harvest this rubber, someone makes a small cut in the bark of the tree and a the milky white substance, latex, flows out of it. It is then mixed with water and acid to make the substance thicker. Also, different companies mix different chemicals into the latex to add color and to make the rubber stronger and stabilized.

Answer 2

Latex rubber is made from the sap of rubber trees. Most of the rubber used today, though, is a petrochemical derivative.

Answer 3

Although much of the modern rubber supply is made from hydrocarbons (crude oil) natural rubbers have always been available made from the latex containing sap of rubber trees and other plants.

Answer 4

Yes rubber trees do exist. See the related links for more information.

Answer 5

rubber