How Is Natural Rubber Made?

Most natural rubber comes from the Pará rubber tree, Hevea brasiliensis, native to the Amazon. Workers cut a thin diagonal groove in the bark, and latex drips into a cup over several hours. The latex is mixed with acid to coagulate the rubber particles, then pressed into sheets and dried or smoked. Raw rubber becomes sticky when hot and brittle when cold, so manufacturers heat it with sulphur in a process called vulcanisation. This creates cross-links between molecules, making it strong and elastic for tyres and other products.