Apparatus for consecutively molding differently colored parts

An injection molding apparatus for making differently colored parts consecutively in a single mold from a plurality of different colorant sources and a single source of resin, comprising:

• a supply channel adapted to be connected to the source of resin and including means for melting the resin in said supply channel to form molten resin;
• a mixing manifold connected to said supply channel and having at least two resin passages, each of said resin passages having an inlet valve, a colorant injection valve adapted to be connected to one of the different colorant sources for introducing a respective colorant into said resin passage, and a mixing element;
• at least two outlet valves, each of said outlet valves being in communication with one of said resin passages and adapted to supply the single mold;
• and
• an injection control means for controlling the introduction of said molten resin through said inlet valves and said colorant through said colorant injection valves selectively into one of said resin passages for mixing in said mixing element to form a mixture of selectively colored resin, and for controlling the injection of said mixture in said selected resin passage into the single mold through said outlet valve in communication with said selected passage.

An injection molding apparatus for making differently colored parts consecutively without purging between making parts of a different color, comprising:

• a single mold;
• a single source of resin;
• a plurality of different colorant sources;
• a supply channel connected to said source of resin and including means for melting said resin in said supply channel to form molten resin;
• a mixing manifold connected to said supply channel and having at least two resin passages, each of said resin passages having an inlet valve, a colorant injection valve connectable to said different colorant sources for introducing a respective colorant into said resin passage, and a mixing element;
• at least two outlet valves, each of said outlet valves being connected to one of said resin passages and to said single mold;
• and
• an injection control means for controlling the introduction of said molten resin from said single source through said inlet valves and the introduction of said colorant through said colorant injection valves selectively into one of said resin passages for mixing in said mixing element to form a mixture of selectively colored resin, and for controlling the injection of said mixture from said selected resin passage into said single mold through a selected outlet valve connected to said selected passage;
• said injection control means being operable substantially immediately thereafter for selectively controlling said inlet valves, said colorant injection valves and said outlet valves to form a second mixture from a different colorant source and inject said second mixture into said single mold without purging between parts.