Theend resultisthatthespringyrubbermoleculesbecome

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Unformatted text preview: athered on the tapper's return journey, poured into containers and delivered to a processing station where it is strained and concentrated. At no stage in the process is the latex and concentrated. At no stage in the process is the latex heated. This means most of the proteins remain in the latex. More stabilizer is added and the latex goes into a centrifuge to remove some of the water, and increase the rubber content of the latex. After centrifuging, the material is known as latex concentrate, and contains roughly 60 percent solid rubber and 40 percent other stuff (water, proteins etc.). This (latex concentrate) is what is used in the dipping process when making gloves. Vulcanization Vulcanization Natural rubber is often vulcanized, a process by Natural rubber is often which the rubber is heated and sulfur, peroxide or bisphenol are added to improve resilience and elasticity, and to prevent it from degrading. Vulcanization greatly improved the durability and utility of rubber from the 1840s on. The successful development of vulcanization is most closely associated with Charles Goodyear. Carbon black is often used as an additive to rubber to improve its strength, especially in vehicle tires. Vulcanization is a treatment of rubber to give it certain qualities, e.g., strength, elasticity, and resistance to solvents, and to render it impervious to moderate heat and cold. Chemically, the process involves the formation of cross­ linkages between the polymer chains of the rubber's molecules. Uncured natural rubber is sticky and can easily Uncured natural rubber is sticky and can easily deform when warm, and is brittle when cold. So it cannot be used to make articles with a good level of elasticity. Vulcanization refers to a specific curing process of rubber involving high heat and the addition of sulfur. It is a chemical process in which polymer molecules are linked to other polymer molecules by atomic bridges composed of sulfur atoms. The end result is that the springy rubber molecules become cross­linked. This makes the bulk material harder, much more durable and also more resistant to chemical attack. It also makes the surface of the material smoother and prevents it from sticking to metal or plastic. Close to 21 million tons of rubber are Close to 21 million tons of rubber are produced each year, of which around 42% is natural. Today Asia is the main source of natural rubber, accounting for around 94% of output. The three largest producing countries (Indonesia, Malaysia and Thailand) together account for around 72% of all natural rubber production. Where Does Rubber Come From? Where Does Rubber Come From? Commercial natural rubber exports {latex exports} originate in: Thailand (1 635 000) {168 000} Indonesia (1 324 000) {26 000} Malaysia (777 000) {109 000} Sri Lanka (68 000) {3 000} Indonesia is a vast equatorial chain of Indones...
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