PURPOSE: To obtain molding having the same density by one shot using cavities mutually different in shape and dimension, by a method wherein the injection amount of material for each cavity is slightly adjusted by regulating the open area of runner by raising and lowering a movable pin.
CONSTITUTION: The open area of runner 11b is established at a fixed value by measuring the density of moldings according to the trial of molding by building the movable pin capable of freely sliding up and down in a bottom force 3 so that the open area of runner 11b can be regulated. After the material is mixed with an aftermixer 5, the material is injected into respective cavities via the runner 11a leading to the cavity 10a and the runner 11b leading to the cavity 10b from the main runner 11 through the gate.
GOTOU MASAO
YOKONO ATARU
