Extrusion die for extrusion blow molding equipment

An extrusion die comprising

• a sleeve support having an outer wall;
• a sleeve element mounted around said sleeve support to define a channel therebetween for a flow of a first resin stream therebetween, said sleeve element being movable between a closed position and an open position relative to said sleeve support and having a surface for mating with said sleeve support in said closed position to close said channel;
• and
• a die member mounted around said sleeve element and said sleeve support, said die member having an inner wall defining a second channel with said sleeve element for a flow of a second resin stream therebetween and facing said sleeve support to define a third channel therebetween for a flow of the first and second resin streams therein with said sleeve element in said open position.

An extrusion die for forming a multi-wall parison for blow molding, said die comprising

• a head having an interior wall;
• a die member within said head having an outer wall defining with said interior wall a first channel for flow of a first resin stream therethrough and an inner wall at one end;
• a sleeve element mounted within said die member to define a second channel therebetween for a second resin and a reservoir for the second resin upstream of said second channel relative to the flow of the second resin, said sleeve being movable relative to said die member to selectively adjust the volume of said reservoir and the size of said second channel;
• and
• a sleeve support within said sleeve element having an outer wall defining a third channel with said sleeve element for flow of a third resin stream therethrough and spaced from said wall of said head to define an exit therebetween for the resin streams.