Equipment Specs
Content
Languages
Revision as of 13:24, 5 February 2012 by Ameliora (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Rubber

From RitchieWiki

Revision as of 13:24, 5 February 2012 by Ameliora (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Materials

Rubber is one of the most useful substances ever utilized by man. Depending on which other chemicals are added during production, rubber can be “as soft as a sponge, as resilient as a rubber band, or as hard as a bowling bowl.”[1] Rubber is used to make automobiles, plastics, military equipment, footwear, medical equipment, and countless other products.[2][3] In industry, rubber is used for hoses, belts, brakes, gaskets, tires, and mouldings.[4]

Contents

[edit] History

[edit] Brazilian Forests Reign

Rubber has been used by the indigenous people of South America for centuries.[5] Rubber comes from the Hevea tree, where it exists naturally within the bark.[6] In its raw form, rubber is a useless milky fluid.[7] The indigenous people solidified rubber by curing it in the smoke of palm nuts.

The first major rubber producing nation was Brazil, who had a near monopoly on the industry. Brazil’s vast tropical forests had a plentiful supply of Hevea trees. Rubber cartels formed and private armies were established to protect large tracts of land. The heads of these cartels, known as rubber barons, were ruthless. In order to obtain more man power, rubber barons raided local villages and took slaves.

The demand for Brazilian rubber coincided with the material gaining exposure in North America. In 1820, traders running routes from South America to New England began to import rubber products, such as rubber threads for clothing and waterproof rubber shoes.[8][9] These products were initially well received, but lost popularity as it became known that the quality of the rubber was poor. Early rubber, before the introduction of vulcanization, was prone to decompose in the summer's heat.[10]

In 1834, an American named Charles Goodyear was exposed to rubber’s shortcomings. He became obsessed with trying to improve the production process to make it more useful for society. Goodyear was thoroughly convinced he was on a god given mission.[11] For many years his determination did not waiver despite numerous failures. He spent all of his money, sold all his possessions, and even went to jail for failing to pay his debts. Yet, he did not lose faith.

In 1839, Goodyear had a breakthrough.[12] He accidentally dropped some rubber and sulphur onto a hot stove element. The rubber transformed into a tough leather-like material, yet kept its flexibility and elasticity. This was the first instance of the modern process of vulcanization. Goodyear realized what he had achieved and looked for funding to further refine the process. However, he had already exhausted the patience of his creditors with his earlier failed attempts. So it took him another five years of impoverished tinkering before he obtained a patent for the process. Goodyear was not concerned with making money. Many other men made fortunes off of his innovation, but he died a poor man in 1860. Fourty years later, the Good Year Tire and Rubber Company was named in his honour.

[edit] Rubber Theft

Throughout the 1800’s there were numerous attempts to transport Hevea seeds to the rest of world to establish homeland sources of rubber, but Hevea seeds were fragile and unable to survive the long journey across oceans. Finally, in 1876, an Englishman sent 70,000 seeds to London’s Botanical Gardens—2,300 survived.[13][14] From this stock, botanists altered the seeds to become more resilient to the elements. Seeds were then sent to Malaysia, Ceylon (Sri Lanka), and Singapore; where plantations were established.

Naturally occuring Hevea trees in Brazil were often located far from each other, while trees on plantations were only a few feet apart. These plantations produced rubber at a much higher rate than previously obtainable; effectively ending Brazilian dominance of the rubber industry. By 1940, Brazil supplied just 1.3 percent of the World’s rubber. To Brazilians, this series of events is still known as the “rubber theft.”[15]

[edit] Introduction of the Automobile

The rubber boom was spawned by the introduction of automobiles in the late 1800’s and early 1900’s. This greatly increased the demand for rubber, which was used for car tires.[16]  Eventually, half the rubber sold in the United States was used to make car tires.[17]

[edit] Early Synthetic Rubber

In 1930 the scientific community started to consider the possibility of producing rubber synthetically using fossil fuels.[18] The following year, one of the first usable synthetic rubbers called Neoprene was produced. Neoprene is well suited to handle both high heat and corrosive materials; it is still used today to line fuel hoses and insulate machinery.[19]

In 1935 German scientists began working on a series of synthetic rubbers known as Bunsa rubbers. These became the basis for the synthetic rubbers later produced by the United States.[20]

[edit] World War II

World War II caused an arms race, which greatly increased demand for rubber. Each Sherman tank produced by the Americans required approximately a ton of rubber, and each warship had 20,000 rubber components.[21] America grew concerned about the possibility of Japan seizing control of rubber plantations in South East Asia; which at that time were supplying 95 percent of the world’s rubber.[22] President Roosevelt declared rubber a “strategic and critical mineral,” and the largest recycling campaign in the history of mankind was undertaken to bolster their stockpiles.[23]

Another government-lead effort brought all of the major rubber producers in America together to share their knowledge and intellectual property rights. Known as the American Synthetic Research Program, this endeavour improved varieties of synthetic rubber, and set the modern standard for how we classify synthetic rubber.[24][25] These efforts proved worthwhile. On December 7, 1941, the Japanese attacked Pearl Harbour. Three months later, Japan invaded Malaysia and the Dutch East Indies and put a stranglehold on the world’s rubber market.

America was forced to take further drastic action: all non-war related use of rubber was banned. The speed limit was reduced to 35 miles per hour (55 km/h) to prevent unnecessary wear on tires.[26] Government encouraged factories to produce synthetic rubber. In 1942, America produced 3,721 tons of synthetic rubber. A year later, it produced 182,259 tons. In 1944, production jumped to 670,268 tons. During 1945, the war’s final year, 756,042 tons was produced, which doubled the world’s production of natural rubber before the war.[27]

[edit] Post-War Synthetic Rubber Adoption

By 1964, synthetic rubber made up 75 percent of the global rubber market. The oil embargo of 1972 doubled its price.[28]

There was a shift in the automotive industry from widespread use of bias tires to radial tires. Radial tires were preferred because they improved fuel efficiency, but they stressed the rubber more than bias tires.[29] Natural rubber was adopted for radial tires because it had stronger chemical bonds than synthetic rubber. By 1993, natural rubber had recaptured 39 percent of the rubber market. Today, nearly half of every auto tire, and the entirety of every aircraft tire, is made of natural rubber. [30]

[edit] Types

[edit] Natural Rubber (NR)

Natural rubber is a naturally occurring product found under the bark of Hevea trees. Natural rubber has some very desirable characteristics: it is very resilient, has good tensile strength, has low heat build up, is tacky, and has excellent water resistance.[31] However, natural rubber is vulnerable to oxidation, gasoline, hydraulic fluid, degreasers, synthetic lubricants, and fire. [32]

[edit] Synthetic Rubber (SR)

Synthetic rubber is a petroleum product which behaves in much the same way as natural rubber. There are numerous varieties of synthetic rubber, categorized based on the type of chemical additives used during vulcanization. Listed below is a description of some of the most common types of synthetic rubber:

[edit] Styrene-Butadiene-Rubber (SBR)

Provides good abrasion resistance, low elasticity, poor behaviour at low temperatures, good heat resistance, good aging resistance, and excellent electrical insulation. Used for asphalt modifications, footwear, adhesives, tires, conveyor belts, and technical goods.[33]

[edit] Polybutadiene Rubber (BR)

Rarely used on its own; often blended with Styrene-Butadiene-Rubber or natural rubber to improve abrasion resistance, elasticity, and flexibility at low temperatures. Used for footwear, adhesives, technical goods, tires, clutches, engine bearings, and plastic modifications.[34]

[edit] Acrylonitrile butadiene rubber (NBR)

Good resistance to oil and fuel, doesn’t distort under heat, and good abrasion resistance. Used for footwear, car parts, fuel hoses, rollers, technical goods, and plastic modifications. [35]

[edit] Butyl Rubber (IIR)

Good resistance to aging, ozone, chemicals, and abrasion. Low permeability to gas, good mechanical properties, and effective electrical insulation. Used for adhesives, automotive hoses, rubberized fabrics, steam hoses, cable insulation, technical goods, and tires. [36]

[edit] Chloroprene Rubber (CR)

Resistant to fire, grease, oil, weather, age, and abrasion. Used for conveyor belts, clutches, drive belts, cables, pneumatic suspension systems, asphalt modifications, footwear, adhesives, and technical goods. [37]

[edit] Isoprene Rubber (IR)

Similar to natural rubber, except more uniform, cleaner, and transparent. Used extensively in the construction industry, cooling and heating hoses, high-performance tires, and plastic cutlery.[38]

[edit] References

  1. [Synthetic Rubber http://www.iisrp.com/synthetic-rubber.html] International Institute of Synthetic Rubber Producers [October 13, 2009].
  2. BRIEF HISTORY and INTRODUCTION OF RUBBER. International Institute of Synthetic Rubber Producers [October 13, 2009].
  3. The main uses of NR. Unctad.org [October 13, 2009].
  4. [Synthetic Rubber http://www.iisrp.com/synthetic-rubber.html] International Institute of Synthetic Rubber Producers [October 13, 2009].
  5. A Brief History of Rubber. MongaBay.com [October 13, 2009].
  6. A Brief History of Rubber. MongaBay.com [October 13, 2009].
  7. [Synthetic Rubber http://www.iisrp.com/synthetic-rubber.html] International Institute of Synthetic Rubber Producers [October 13, 2009].
  8. BRIEF HISTORY and INTRODUCTION OF RUBBER. International Institute of Synthetic Rubber Producers [October 13, 2009].
  9. BRIEF HISTORY & INTRODUCTION OF RUBBER. International Institute of Synthetic Rubber Producers [October 13, 2009].
  10. Charles Goodyear and The History of Rubber. About.com [October 13, 2009].
  11. Charles Goodyear and The History of Rubber. About.com [October 13, 2009].
  12. A Brief History of Rubber. MongaBay.com [October 13, 2009].
  13. A Brief History of Rubber. MongaBay.com [October 13, 2009].
  14. BRIEF HISTORY AND INTRODUCTION OF RUBBER. International Institute of Synthetic Rubber Producers [October 13, 2009].
  15. A Brief History of Rubber. MongaBay.com [October 13, 2009].
  16. A Brief History of Rubber. MongaBay.com [October 13, 2009].
  17. The International Natural Rubber Market, 1870-1930. Eh.net [October 13, 2009].
  18. Synthetic Rubber. PackagingToday.com [October 13, 2009].
  19. Synthetic Rubber. PackagingToday.com [October 13, 2009].
  20. Synthetic Rubber. PackagingToday.com [October 13, 2009].
  21. BRIEF HISTORY & INTRODUCTION OF RUBBER. International Institute of Synthetic Rubber Producers [October 13, 2009].
  22. BRIEF HISTORY AND INTRODUCTION OF RUBBER. International Institute of Synthetic Rubber Producers [October 13, 2009].
  23. Government Rubber. The Polymer Science Learning Center [October 13, 2009].
  24. BRIEF HISTORY AND INTRODUCTION OF RUBBER. International Institute of Synthetic Rubber Producers [October 13, 2009].
  25. Government Rubber. The Polymer Science Learning Center [October 13, 2009].
  26. BRIEF HISTORY AND INTRODUCTION OF RUBBER. International Institute of Synthetic Rubber Producers [October 13, 2009].
  27. Synthetic Rubber. PackagingToday.com [October 13, 2009].
  28. A Brief History of Rubber. MongaBay.com [October 13, 2009].
  29. A Brief History of Rubber. MongaBay.com [October 13, 2009].
  30. A Brief History of Rubber. MongaBay.com [October 13, 2009].
  31. The main uses of NR. Unctad.org [October 13, 2009].
  32. Description and technical features. Unctad.org [October 13, 2009].
  33. Synthetic rubber. Transport Information Service [October 13, 2009].
  34. Synthetic rubber. Transport Information Service [October 13, 2009].
  35. Synthetic rubber. Transport Information Service [October 13, 2009].
  36. Synthetic rubber. Transport Information Service [October 13, 2009].
  37. Synthetic rubber. Transport Information Service [October 13, 2009].
  38. Synthetic rubber. Transport Information Service [October 13, 2009].