What is the rubber ? 

RUBBER
Rubber is actually a name for tree. The materials extracted from itself and its natural juice which is derived from its latex has found its place in the use of industrial area. In recent years, naturally with the production of synthetic rubber besides rubber, many rubber types have emerged. Rubbers most important feature is that it has a high elasticity and its stretching returning back to its original for. This is the basis for rubber processing industries development and its use in almost all industries.
 In the whole world, there is over 15 million tons of rubber is produced; approximately one third of this is natural rubber. The rest is synthetic rubber made of chemical material derived from petroleum. Natural rubber is derived from the milky natural liquid discharged from rubber trees (Hevea brasiliensis) skin. The best place this tree is grown is around the Equator region. Main countries growing natural rubber are: Brazil, Nigeria, Liberia, Zaire, South India, Malaysia, Indonesia, Thailand and Philippines. The production of natural rubber is also realized in small farms besides plantations (large farms).
 
Synthetic rubber on the other hand, is produced in many countries in factories established near petroleum purification systems. With U.S.A. being the leader, it is mainly produced in Japan, Germany and France.  There is more than 100 different synthetic rubber types. Rubber is a flexible material; when stretched it can expand to multiple times of its original size or if pressed its shape can be changed but when left free it will again return to its shape and dimension it had at the beginning. 

     In south and Middle America, a minimum 900 years old chunk of rubber has been found which are left from Maya civilization. It is Christopher Columbus who brought first information to Europe. Columbus saw when Haiti Natives were playing with a ball made from tree gum. Two French botanists; François Fresneau and Charles de la Condamine in the 18th century; stayed for a long time in South America. Fresneau was the first to introduce rubber in 1730. Native Americans were calling the rubber tree cahucho meaning “the crying tree”. In 1736, La Condamine has sent to Paris rubber samples and explained how the natives were making shoes, war shield and bottle from rubber; in addition he explained how they were making use of this material as waterproof material. Until the middle of 19th century, rubber stayed as a rare found and expensive material. Rubber at the beginning could be obtained only from South America and especially from Brazil. In 1876, Henry Wickham has gathered 70 thousand rubber seeds and brought them to Kingdom Botanic Gardens in Kew near London, he then ensured for them to be planted in lemon plants. A great portion has been sent to Botanic Gardens in Asia, especially Sri Lanka. In the mean time it is assumed that around 11 plants reached Malaysia. In 1889, Nicholas Ridley who was brought to manage Botanic Gardens in Singapore, has developed system to obtain new latex and thereafter rubber production has increased steadily. This way, the importance of rubber obtained from plantations in Southeast Asia has gained increasing importance in comparison to raw rubber coming from South America.
In 1907, when plantation rubber meets %5 of worlds total requirement, when 1914 was reached this ratio has increased to over ½50.

RUBBER TYPES AND PROPERTIES

Nitric Rubber (NBR)
It is a general purpose material recommended for a large portion of applications resistant to oil and grease. It has different mixtures for fuel and industry liquids. Its has low resistance to glycol based break fluids and EP additive oils. Nitric rubber typically is used between temperatures of -40° C and 105° C, for work with intervals it can endure up to 120° C. It is preferred from price/function balance point of view. In gasket production, mushroom filled nitrite mixtures are used.  The tolerance properties of this material are similar to nitrite. The existence of the mushroom additionally ensures squeezing (decrease in mass) properties. Mushroom nitrite only finds usage area in static applications.
Poly acrylic rubber (ACM)
It is more durable in high heat temperatures and EP additive oils in comparison to rubber. Generally, it is used up to 150° C'. Its ozone resistance is good. Fuel resistance and low temperature tolerance is weak (-30°C min.). It is especially used in a toothed box pads.  
Silicone Rubber (MQ, VMQ, PVMQ)
It is used in temperatures between -60° C and 200° C. With intervals it can last up to 250° C'. Its main usage area is crank mats/pads. Its flexibility property, air resistance and ozone tolerance are high. It is not recommended in Fuels, EP additive oils and in applications requiring high mechanical properties.
Fluorocarbon Rubber (FKM)
It is used in temperatures between 30° C and 220° C.  It is resistant to majority of grease, oil fuel, solvent and chemical substances.  It is used in high temperature and high cycle environments and around crank pads, but it is expensive. Its resistance to fluidities containing Kenton, amine, ester is not good.
Ethyl Propane Rubber (EPM, EPDM)
It can be used between -40° C and 150° C. Its resistance to Phosphate ether fluidities, glycol based break fluids, and water vapor, ozone and weather conditions is good. It is not suited for fuels and petroleum based oils.
Styrene Butadiene Rubber (SBR)
It is resistant to glycol based break fluids, acid and bases and alcohol. This material is used between -50° C and 100° C.  It is not persistent to fuels and petroleum based oils.

Natural Rubber (NR)
Its usage temperature is between -60° C and 90° C. Because of its environment resistance, it shows similar properties to SBR. It is used in places where high flexibility and mechanic properties are needed.
Politetrafloroetilen (PTFE)
It is a plastic material resistant to almost all chemical materials used in the industrial applications. It has usage in temperatures between -260° C and 260° C . It is a lsolid material with lowest abrasion multiplier. It does not indicate any sticking properties; it is oil less bedding material. Some types are very good electric conductive. Based on its application area it is used raw, glass fibred, carbonated, black leaded, bronzed, molybdenum sulfated PTE.
Polyamide (PA)
It is widely known as nylon. It is used between -20° C and 90° C. In the special types, usage limit can increase up to 140° C'. Its abrasion and corrosion properties are extremely well. It is resistant against oils, fuels, ether, ketenes.
Hydrogen Nitric Rubber (HNBR)
It is derived from Hydrogen Nitric Rubber. The properties of the materials prepared in this way are high mechanic powers and that they are more resistant to abrasion. Environment tolerance is similar to the one of NBR. Usage limit is 150ºC.
Thermoplastic Polyurethane (TPU)
With the injection molding of TPU, there are two mechanical properties enabling it to be processed effectively. Real advantages of TPU are high resistance against abrasion; a wide temperature heat flexibility interval and its resistance against oils, grease oils and many solvents.This ratio has increased to over ½50.