Method for molding plastic shutter for magnetic disk cartridge

摘要

In a method for injection molding a plastic shutter for a magnetic disk cartridge, the shutter having windows corresponding to an opening formed in a magnetic disk cartridge and being substantially U-shaped in section, the diameter of an injection cylinder for injecting molten resin for forming the shutter is determined according to the following equation: D2=AxCxM / pi where D is the diameter (mm) of the injection cylinder, C is the number of the plastic shutters molded simultaneously with one metal mold, M is the volume (cm3) of the plastic shutter, and A is the cylinder coefficient of the injection cylinder and is limited as follows: 130