In the first stage, the hot bitumen is pumped at the required temperature (usually around 185ºC) into agitated tank. The thermo-plastic rubber is added and stirred for and equal distribution. Following the mix flows to the mill by gravity. The mix is passed through the mill to physically reduce the thermo-plastic rubber particles in size by mechanical shear, accompanied by a significant input of heat energy. This provides rapid and efficient disintegration of the thermo-plastic rubber particles in the bitumen.