Once rubber sheets are made according to the characteristics of each part of the tire through the ‘mixing Process,’ rubber is then created into a certain regular width and thickness through the ‘extrusion process.’ Here, the treads (outer surface of the tire) and sidewalls (sides of the tire) are created, which is an important process for cozy and comfortable driving. Once rubber sheets are made according to the characteristics of each part of the tire through the ‘mixing Process,’ rubber is then created into a certain regular width and thickness through the ‘extrusion process.’ Here, the treads (outer surface of the tire) and sidewalls (sides of the tire) are created, which is an important process for cozy and comfortable driving.