Let us discuss the kinetic energy at the time of opening and closing the moving falf mold after an injection mold has been installed in the injection molding machine. (See Fig. 1)

Kinetic energy is required when an object moves at a certain velocity. When the amount of kinetic energy becomes large, in order to stop the mold, a brake has to be applied that can withstand an equivalent or higher amount of energy. In addition, if the mold clamping is not done in the state in which the kinetic energy has been reduced sufficiently, there is the danger of the mold getting damaged or broken.

The equation for calculating the kinetic energy is the following.

The following points are evident from this equation

	1.	The kinetic energy E is proportional to the mass m on the movable side.
	2.	The kinetic energy E is proportional to the square of the movement velocity v on the movable side.

Therefore, as the mass of the moving half becomes large, even the kinetic energy becomes large proportionally. If the speed of mold opening and closing is made higher, even the energy increases proportional to the square of the speed.

Therefore, in the case of a mold in which a large number of core pins with ejector structure or pillbox structure have been placed, or a mold having abnormally shaped parting surface, at the time of mold clamping, if the slowing down (speed reduction) is not made sufficiently, since the mold may break due to the kinetic energy, it is necessary to take sufficient care.