Die, system, and method for coextruding a plurality of fluid layers

Abstract

A die for coextruding a plurality of fluid layers generally includes a primary forming stem, one or more distribution plates, and a microlayer assembly. The microlayer assembly includes a microlayer forming stem and a plurality of microlayer distribution plates.

1 . A die for coextruding a plurality of fluid layers, comprising:
 a. a primary forming stem;   b. one or more distribution plates, each of said plates having a fluid inlet and a fluid outlet, the fluid outlet from each of said plates being in fluid communication with said primary forming stem and structured to deposit a layer of fluid onto said primary forming stem; and   c. a microlayer assembly, comprising
 (1) a microlayer forming stem, and 
 (2) a plurality of microlayer distribution plates, each of said microlayer plates having a fluid inlet and a fluid outlet, the fluid outlet from each of said microlayer plates being in fluid communication with said microlayer forming stem and structured to deposit a microlayer of fluid onto said microlayer forming stem, said microlayer plates being arranged to provide a predetermined order in which the microlayers are deposited onto said microlayer forming stem to form a substantially unified, microlayered fluid mass on said microlayer forming stem, 
   wherein, said microlayer forming stem is in fluid communication with said primary forming stem such that said microlayered fluid mass flows from said microlayer forming stem and onto said primary forming stem.   
   
   
       2 . The die of  claim 1 , wherein said distribution plates have a thickness ranging from about 0.5 to about 2 inches and said microlayer distribution plates have a thickness ranging from about 0.1 to about 0.5 inch. 
   
   
       3 . The die of  claim 1 , wherein said microlayer distribution plates have one or more flow channels connecting said fluid inlet with said fluid outlet, said flow channels having a spiral-shaped configuration. 
   
   
       4 . The die of  claim 1 , wherein
 said microlayer distribution plates each have an orifice extending through said plate;   said fluid outlet of each of said microlayer distribution plates is positioned adjacent to said orifice; and   said microlayer forming stem extends through the orifice of each of said microlayer distribution plates.   
   
   
       5 . The die of  claim 1 , wherein said primary forming stem and said microlayer forming stem are substantially coaxially aligned with one another. 
   
   
       6 . The die of  claim 5 , wherein said microlayer forming stem is external to said primary forming stem. 
   
   
       7 . The die of  claim 1 , wherein
 said distribution plates and said microlayer assembly are axially positioned along said primary forming stem; and   the fluids from said distribution plates and said microlayer assembly flow in an axial direction along said primary forming stem.   
   
   
       8 . The die of  claim 7 , wherein said distribution plates are located upstream of said microlayer assembly. 
   
   
       9 . The die of  claim 7 , wherein said microlayer assembly is located upstream of said distribution plates. 
   
   
       10 . The die of  claim 7 , wherein said microlayer assembly is positioned between one or more upstream distribution plates and one or more downstream distribution plates. 
   
   
       11 . The die of  claim 1 , wherein said microlayer assembly comprises at least about 5 microlayer plates. 
   
   
       12 . The die of  claim 1 , further including one or more additional microlayer assemblies. 
   
   
       13 . A system for coextruding a plurality of fluid layers, comprising:
 a. a die, comprising:
 (1) a primary forming stem, 
 (2) one or more distribution plates, each of said plates having a fluid inlet and a fluid outlet, the fluid outlet from each of said plates being in fluid communication with said primary forming stem and structured to deposit a layer of fluid onto said primary forming stem, and 
 (3) a microlayer assembly, comprising
 (a) a microlayer forming stem, and 
 (b) a plurality of microlayer distribution plates, each of said microlayer plates having a fluid inlet and a fluid outlet, the fluid outlet from each of said microlayer plates being in fluid communication with said microlayer forming stem and structured to deposit a microlayer of fluid onto said microlayer forming stem, said microlayer plates being arranged to provide a predetermined order in which the microlayers are deposited onto said microlayer forming stem to form a substantially unified, microlayered fluid mass on said microlayer forming stem, wherein, said microlayer forming stem is in fluid communication with said primary forming stem such that said microlayered fluid mass flows from said microlayer forming stem and onto said primary forming stem; and 
 
   b. one or more extruders in fluid communication with said die to supply one or more fluids to said die.   
   
   
       14 . A method of coextruding a plurality of fluid layers, comprising:
 a. directing a fluid through a distribution plate and onto a primary forming stem, said distribution plate having a fluid inlet and a fluid outlet, the fluid outlet from said plate being in fluid communication with said primary forming stem and structured such that said fluid is deposited onto said primary forming stem as a layer;   b. forming a substantially unified, microlayered fluid mass on a microlayer forming stem by directing at least one additional fluid through a microlayer assembly, said microlayer assembly comprising a plurality of microlayer distribution plates, each of said microlayer plates having a fluid inlet and a fluid outlet, the fluid outlet from each of said microlayer plates being in fluid communication with said microlayer forming stem and structured to deposit a microlayer of fluid onto said microlayer forming stem, said microlayer plates being arranged to provide a predetermined order in which the microlayers are deposited onto said microlayer forming stem; and   c. directing said microlayered fluid mass from said microlayer forming stem and onto said primary forming stem to merge said microlayered fluid mass with said fluid layer from said distribution plate.   
   
   
       15 . The method of  claim 14 , wherein the fluid directed through said distribution plate is substantially the same as the fluid directed through said microlayer assembly. 
   
   
       16 . The method of  claim 14 , wherein the fluid directed through said distribution plate is different from the fluid directed through said microlayer assembly. 
   
   
       17 . The method of  claim 14 , wherein said fluid layer from said distribution plate is deposited onto said primary forming stem prior to the deposition of said microlayered fluid mass onto said primary forming stem such that said fluid layer from said distribution plate is interposed between said microlayered fluid mass and said primary forming stem. 
   
   
       18 . The method of  claim 14 , wherein said microlayered fluid mass is deposited onto said primary forming stem prior to the deposition of said fluid layer from said distribution plate onto said primary forming stem such that said microlayered fluid mass is interposed between said fluid layer from said distribution plate and said primary forming stem. 
   
   
       19 . The method of  claim 14 , wherein:
 each of said microlayers has a thickness M,   said fluid layer from said distribution plate has a thickness D, and   the ratio of M:D ranges from about 1:1 to about 1:8.