Natural rubber has many impressive qualities—it can bounce, be put under extreme pressure, and even be used to erase (or “rub out”) pencil marks on paper. But of all its fascinating abilities, natural rubber is best known for its elastomeric properties; it is easily stretched and can snap back into its original shape when released.
Created using the sap (latex) secreted from the Haveabrasilliensis (or ‘rubber tree’) rubber can be used to create an enormous range of products from surgical gloves to pneumatic tires, to party balloons to golf balls.
In order to harvest rubber, a thin layer of bark is cut and a spout is hammered into the tree.Then, the latex is allowed to drip into a container for about three hours. Finally, the latex coagulates, or solidifies, and the cut in the tree’s bark seals up (like a blood clot seals up a wound).
Did You Know? Latex is a complex mixture of alkaloids, gums, oils, resins, sugars, starches, and tannins. When exposed to air, it congeals to form a solid mass.
Once the latex has been collected, ammonia is added to stop the coagulation process.This causes the sap to split into two-phases which are then separated by centrifugation and sold as high and low ammonia concentrates.
Did You Know? Centrifugation uses gravity to separate materials of different densities by spinning them at incredibly high speeds.
These concentrates are further processed by adding preservatives, antioxidants, and accelerators and then transformed into products. The majority of this rubber is used to create extruded rubber products, vehicle tires, and injected molded goods while a smaller portion is used for dipped products, such as condoms, balloons, and rubber gloves.
Did You Know? Dipped products are the most common cause of latex allergies.
Latex:How Products are Made
International Rubber Study Group
Woods, J.A., Lambert, S., Platts-Mills, T.A.E., Drake, D.B., and R.F. Edlich. 1997.Natural rubber latex allergy: Spectrum, diagnostic approach, and therapy. J. Emergency Medicine. 15: 71-85. Information on Rubber - UNCTAD
Article first published May 18, 2011