What is Natural Rubber?

Natural rubber is a product consisting of long chains of loosely bound isoprene polymers. When pulled, the threads bind together, giving the rubber its characteristic elasticity. While synthetic rubber, which is derived from petrochemicals and  natural rubber is derived from the sap of the rubber tree. Although other manufacturers also produce latex, the rubber tree is the most successful rubber production source in the world, providing 99 percent of natural rubber.

Production of Natural Rubber

Natural rubber production involves harvesting rubber trees for sap, which is then processed using heat and chemicals for production. When the tree is cut, the juice will fall into the glass. At this stage, one third of the latex is rubber in colloidal suspension, and the other three are water. To convert latex into rubber, it is mixed with formic acid to coagulate the rubber into a curd, which is then washed and pressed into blocks or flakes before being smoked.

The rubber is then made more by passing through chewing machines and mixed with chemicals to improve its properties. Finally, the rubber is formed into the desired shape by calendaring or extrusion, and then vulcanized by a process that increases its strength, elasticity and flexibility. Vulcanization involves heating the rubber with sulfur in a curing pressure like cooker to 160 to 200 degree C according to the application requirements. The chain ring effect of polyisoprene provides strength and resistance when removing adhesive from raw rubber. Despite the invention of synthetic rubber in the 1930s, natural rubber is still widely used today and accounts for about half of the rubber industry.

Properties of Rubber

Natural rubber is known for its flexibility and durability as well as its sensitivity to the environment such as impurities and hydrocarbons. Among the different types of rubber, natural rubber is the most flexible and is resistant to water and some chemicals. It resists cuts, rips, scrapes, abrasions and tears and works in temperatures from -58 to 212 degrees Fahrenheit. Natural rubber also exhibits high tensile strength and adheres easily to other materials.

However, natural rubber is not as good as other rubbers such as neoprene in terms of resistance to heat, light and ozone. It is different depending on the tree that produces it, and there are natural impurities. It is resistant to water and some chemicals, but also sensitive to oil, grease and non-polar solvents.

Natural Rubber Application

Natural Rubber is used in applications requiring corrosion and high temperature. Natural rubber is a popular choice for engineering applications that require high levels of strength and compressibility, including anti-vibration mounts, drive couplings, springs, bearings, rubber bands, and adhesives.