The uneven temperature of the drawing die is related to the injection cycle. After injection, the temperature of the cavity rises to the highest. At this time, the hot melt hits the cold wall of the cavity, and the temperature drops to the lowest when the parts are removed. The function of the mold temperature machine is to keep the temperature constant between θ2min and θ2max, which means to prevent the temperature difference △θw from fluctuating up and down during the production process or the gap.