Technical Information
WHAT IS RUBBER?
The word rubber is derived from the locals who live around the Amazon River, calling a tree "caa-o-chu". In the language of the natives, “caa” means wood-wood, “o-chu” means flowing-weeping. “caa-o-chu” means weeping tree. The liquid obtained to produce elastic materials by coagulation of the milky liquid, which is the sap of the rubber tree, is called rubber.
RUBBER TYPES
NR : Natural Rubber
SBR : Styrene Butadiene Rubber
CR : Chloroprene Rubber (Neoprene)
NBR : Nitrile Rubber
EPDM : EPDM Rubber
CSM : Hypalon Rubber
VMQ : Silicone Rubber
FKM : Viton Rubber
CO/ECO : ECO Rubber
NR - NATURAL RUBBER
Natural Rubber is obtained from the rubber tree. Although there are many varieties, only the Havea Brasiliensis type, which grows in the Amazon region, is used commercially. It is not a homogeneous product due to its natural structure, but nevertheless it has been classified into different product groups according to analytical and appearance evaluation criteria.
Properties
* Mechanical properties such as excellent tensile strength, elasticity and tear resistance
* Wide hardness range from 35 to 90 Shore A.
* High elasticity, excellent dynamic properties and low compression set.
* Excellent electrical properties.
* It is sensitive to ozone. Resistance to atmospheric conditions can be improved with the addition of antiozonant combined with waxes.
* Temperature range -50 to 90 C.
SBR - styrene BUTADIENE RUBBER
More than half of the synthetic rubbers produced in the world are SBR. SBR contains approximately 23% styrene. An increase in this ratio causes an increase in hardness and at the same time a decrease in low temperature resistance and flexibility properties.
Properties
* They require reinforcing fillers to provide good mechanical properties and higher abrasion resistance can be achieved than natural rubber.
* They are similar to natural rubber, but their aging and temperature resistance is better.
* It has lower flexibility compared to natural rubber.
* It has moderate tear, ozone and atmospheric resistance.
* Temperature range -50 to 110 C.
CR - CHLOROPRENE RUBBER (NEOPRENE)
It is rubber that gives the most balanced combination of expected properties. The chlorine atom increases the oil resistance level and thus places it between natural rubber and nitrile rubber.
Properties
* Excellent wear resistance and super mechanical properties.
* It has lower elasticity than natural rubber at low hardnesses, but higher elasticity at 60 Shore A and above hardnesses.
* Offers good temperature and ozone resistance.
* Flame retardant.
* Adheres well to metal.
* Temperature range -25 to 125 C .
NBR - NITRILE RUBBER
Depending on the amount of ACN, they are classified as low ACN (18-24%), medium ACN (34%) and high ACN (50%). By increasing the amount of ACN: Oil and fuel resistance increases. Tensile strength, abrasion resistance, hardness, temperature resistance and sealing properties increase. Flexibility values at low temperatures decrease.
Properties
It is resistant to oils and can be formulated for applications requiring high temperatures.
* It has good mechanical properties.
* It does not leak gases.
* Aging properties are moderate.
* Good adhesion to metal.
* Its low temperature resistance is moderate, but it can be used in applications reaching up to -40 C with the use of appropriate plasticizers.
* Temperature range -30 to 120 C.
EPDM - EPDM RUBBER
The copolymer (EPM) consisting of ethylene and propylene can only be cooked with peroxide and radiation, whereas the standard sulfur cooking method can be used by adding Diene (EPDM) to them, thus increasing the tear resistance.
Properties
* Excellent resistance to aging, ozone, ultraviolet rays and atmospheric conditions.
* Excellent electrical property and radiation resistance.
* Moderate adhesion to metal.
* Temperature range -40 to 120 C . However, it can be formulated for continuous operation at 140°C.
CSM - HYPALON RUBBER
Properties
* Excellent resistance to oxidation, ozone and atmospheric conditions.
* Excellent resistance to hydrocarbon solvents.
* Flame resistant.
* Moderate metal adhesion.
* Temperature range -35 to 140 C.
VMQ - SILICONE RUBBER
Unlike other synthetic rubbers, they contain no carbon in the molecular chain, only silicon and oxygen atoms.
Properties
* It has excellent heat resistance in dry environments (200 220 C). In case of aging in contact with high pressure steam (130-140 C) or in closed environments where there is no oxygen, there may be a decrease in thermal resistance due to hydrolysis.
* Ozone, ultraviolet rays and atmospheric conditions do not change their properties.
* It has good insulating property.
* It has the feature of self-extinguishing the flame. Residues (silica) resulting from combustion resulting from prolonged exposure to flame are excellent insulators.
* It is physically harmless, so it is suitable for medical applications.
* Temperature range -70 to 220 C.
FKM - VITON RUBBER
They are known as fluoroelastomer rubber. Its chemical resistance and low and high temperature resistance are directly proportional to the amount of fluorine it contains.