It’s hard, almost impossible, to imagine a world without rubber since it is the one material that allows so much of our modern life to exist. Even with developments in creating synthetic rubber with specific properties, over 40% of the rubber used each year continues to be natural rubber. What are the steps that go into natural rubber processing that makes it usable for so much?
The natural rubber latex is actually the sap of the rubber tree, so the trees are tapped by cutting the bark and the sap flows into collection cups, where it can be collected by workers. The workers have to be careful not to cut too deeply or too often, or else the tree will be killed.
The collected latex sap is brought to areas to be processed, where is is strained for impurities, and then is allowed to coagulate into a sticky mass. This is then rolled out into sheets to remove more water, then the sheets are hung out to dry in the air, thickening and hardening the rubber into something easier to transport.
Once these sheets of dried natural rubber get to their location, they can be shredded and put through rubber drying equipment to get it to the needed moisture for melting. Then these dried rubber shreds are melted and used for creating a final product.
More commonly though, the uncured natural rubber is put through the process of vulcanization, which hardens and strengthens natural rubber by heating it with sulfur. This technique was discovered by Charles Goodyear when trying to figure out how to stop natural rubber from hardening in the winter and softening in the summer. Most car tires today are still made from vulcanized natural rubber that has gone through rubber processing equipment, and about half of all natural rubber actually goes towards making tires.