Plastic co-extrusion apparatus with selectable polymer flow control and product produced using the apparatus

Abstract

Co-extrusion apparatus for manufacturing a laminated plastic film or sheet comprises a plug-type layer sequencer including a plurality of channels for conducting a plurality of polymer flows; a transitional aspect ratio block for inducing the plurality of polymer flows to converge; and a flow velocity profiler cartridge for combining the plurality of polymer flows to form the film. In accordance with one embodiment, the layer sequencer includes a tapered selector pin which minimizes mechanical damage when the selector pin is removed. In accordance with another embodiment, the flow velocity profiler cartridge includes inserts fitting within cavities for controlling the polymer flows which form the layers of the film or sheet manufactured by the apparatus. At least one such insert defines lanes within an associated cavity so as to promote the formation of lanes of differing polymer composition within at least one layer of the laminated sheet or film.

1 . A co-extrusion apparatus comprising a layer sequencer, a transitional aspect ratio block, and a combining block,
 said layer sequencer comprising a housing and a selector pin which cooperates with said housing to define a plurality of channels;   said transitional aspect ratio block comprising a plurality of passages which communicate with said channels and which converge;   said combining block comprising a plurality of cavities which communicate with said passages and which converge;   said housing defining a socket for receiving said selector pin, said socket having an opening and a socket profile tapering inwardly from said opening; and said selector pin defining a tapering selector pin profile substantially matched to said socket profile.   
     
     
         2 . A co-extrusion apparatus as recited in  claim 1 , wherein said housing defines a plurality of inlets and a plurality of outlets, said plurality of channels providing communication between said plurality of inlets and said plurality of outlets. 
     
     
         3 . A co-extrusion apparatus as recited in  claim 1 , wherein:
 said housing defines a plurality of inlets and said plurality of outlets, and   said selector pin defines connecting channel sections of said channels for selective communication between said plurality of inlets and said plurality of outlets.   
     
     
         4 . A co-extrusion apparatus as recited in  claim 1 , wherein at least a portion of said selector pin is frustoconical. 
     
     
         5 . A co-extrusion apparatus as recited in  claim 1 , wherein said combining block comprises a removable flow velocity profiler cartridge comprising a cartridge body which defines said plurality of cavities and a plurality of inserts positioned within said cavities. 
     
     
         6 . A co-extrusion apparatus as recited in  claim 5 , wherein at least one of said inserts comprises a pair of parallel rails spaced along a width direction, a web extending between said pair of parallel rails and at least one indentation formed in said web. 
     
     
         7 . A co-extrusion apparatus as recited in  claim 1 , wherein said combining block comprises a removable flow velocity profiler cartridge, said flow velocity profiler cartridge comprising a cartridge body defining a plurality of cavities and a plurality of inserts received in said plurality of cavities; at least one of said inserts comprising a pair of parallel rails spaced along a width direction, a web extending between said pair of parallel rails, said web having at least two indentations forming at least two passageways through said flow velocity profiler cartridge. 
     
     
         8 . A co-extrusion apparatus comprising a layer sequencer, a transitional aspect ratio block, and a flow velocity profiler cartridge,
 said layer sequencer comprising a plurality of channels;   said transitional aspect ratio block comprising a plurality of passages which communicate with said channels and which converge;   said flow velocity profiler cartridge defining a plurality of cavities which communicate with said passages and which converge, said flow velocity profiler cartridge comprising a plurality of inserts each positioned in one of said plurality of cavities; at least one of said plurality of inserts comprising a pair of parallel rails spaced along a width direction, a web extending between said pair of parallel rails and at least two indentations formed in said web and forming at least two passageways through said flow velocity profiler cartridge.   
     
     
         9 . A co-extrusion apparatus as recited in  claim 8 , wherein said flow velocity profiler cartridge comprises at least two inlets communicating with one of said cavities such that each of said at least two passageways communicate with one of said at least two inlets. 
     
     
         10 . A co-extrusion apparatus as recited in  claim 8 , wherein each of said at least two indentations has a rectangular cross-section. 
     
     
         11 . A co-extrusion apparatus as recited in  claim 8 , wherein said flow velocity profiler cartridge comprises a pair of side caps enclosing side portions of said cartridge body. 
     
     
         12 . A laminated plastic material comprising a plurality of layers, at least one of said plurality of layers comprising a plurality of lanes, a first of said lanes comprising a first polymer composition, a second of said lanes comprising a second polymer composition, said second polymer composition being different from said first polymer composition. 
     
     
         13 . A laminated plastic material as recited in  claim 12 , wherein said first lane is a first color and said second lane is a second color, said second color being different from said first color. 
     
     
         14 . A laminated plastic material as recited in  claim 13 , wherein said first and second lanes are adjacent to each other and a feathered weld line is positioned between said first and second lanes. 
     
     
         15 . A laminated plastic material as recited in  claim 12 , wherein said first and second lanes are adjacent to each other and have different heat conduction properties. 
     
     
         16 . A laminated plastic material as recited in  claim 12 , wherein said first and second lanes are adjacent to each other and have different mechanical properties. 
     
     
         17 . A laminated plastic material as recited in  claim 12 , wherein said first and second lanes are adjacent to each other and have different tear strengths. 
     
     
         18 . A laminated plastic material as recited in  claim 12 , wherein at least one of said plurality of lanes comprises an extrudable adhesive. 
     
     
         19 . A laminated plastic material as recited in  claim 12 , wherein said first and second lanes are adjacent to each other and an adhesion of said first lane is lower than an adhesion of said second lane. 
     
     
         20 . A laminated plastic material as recited in  claim 12 , wherein at least one of said plurality of lanes comprises a functional coating. 
     
     
         21 . A laminated plastic material as recited in  claim 12 , wherein at least one lane of said plurality of lanes comprises acrylic resin.