After the latex has been harvested and purified, it is combined with acetic or formic acid to form rubber slabs. Next, the slabs are squeezed between rollers to remove excess water and pressed into bales or blocks, usually 2 or 3 square feet. The rubber is then shipped to a rubber factory, where the slabs are machine cut into small pieces and mixed in a Banbury mixer with other ingredients—sulfur to vulcanize it, pigments to color it, and other chemicals to increase or diminish the elasticity of the resulting rubber bands. After being milled, the heated rubber strips are fed into an extruding machine that forces the rubber out in long, hollow tubes. Goodyear, Hancock, and Perry, manufacturing effective rubber bands became possible.
In the late nineteenth century, British rubber manufacturers began to foster the development of rubber plantations in British colonies like Malaya and Ceylon. Rubber plantations thrived in the warm climate of Southeast Asia, and the European rubber industry thrived as well, because now it could avoid the expense of importing rubber from the Americas, which lay beyond Britain's political and economic control.
The processing start from cleaning unsmoked sheets in pool water, hanging rubber sheet on hanging trolley, smoking in smoke chambers with temperature control at below 65°c,clipping out all overheat and foreign matters contamination, grading smoked sheet into grade number one to number five (RSS-1,RSS-2,RSS-3,RSS-4,RSS-5)