The dynamics of injection molding t

The dynamics of injection molding thermoplastics means that energy is added to the plastic to melt the plastic and then after injecting the plastic into the mold we must pull that energy back out to allow the melted plastic to resolidify. The temperature of the molded part must drop to an appropriate temperature to allow the part to be ejected from the mold in a state that will retain its molded shape; if ejected too hot the part will warp and change shape as it continues to cool outside of the mold. Every BTU of energy that is put into the plastic during the melting stage must be removed during the cooling stage. It is important to remember that the parts can be ejected at a temperature that is often well above the mold temperature, and cooling will continue outside of the mold after ejection.