INJECTION MOLDING FILTER ASSEMBLY

摘要

This invention relates to an improved injection molding filter assembly to be located between the molding machine and the mold. The assembly has an elongated inner torpedo member with a generally cylindrical outer surface which is centrally located in a passage through a hollow outer member. The passage is defined by a generally cylindrical inner wall which is interrupted by an even number of inwardly opening longitudinally extending channels. Inlet channels extending from the inlet of the assembly and dead ending adjacent the outlet alternate with outlet channels extending from the outlet of the assembly and dead ending adjacent the inlet. Filtering apertures are formed between the outer surface of the torpedo member and the lands between the inlet and outlet channels through which the melt flows from the inlet channels to the outlet channels. A single elongated aperture may be formed at each land or a plurality of smaller apertures may be formed by providing alternating laterally extending ridges and grooves on the inner surfaces of the lands and/or on the outer surface of the torpedo member. Contaminants which are too large to pass through the filtering apertures accumulate adjacent the dead ends of the inlet channels. The outer member has a collar portion which may be detached to take out the torpedo member for periodic removal of accumulated contaminants. The location of the channels in the outer member provides improved heat flow characteristics and allows the width of the filtering slits to be quickly and easily changed by substituting a relatively inexpensive torpedo member having a different diameter.