Methods for Forming Seamless Conformable Booties and Waterproof Breathable Socks

Abstract

Waterproof, breathable socks, booties, shoe inserts, and footwear assemblies containing the shoe inserts are provided. The booties and shoe inserts include a laminate of a seamless ePTFE membrane and at least one textile. The bootie is conformable over a range of sizes and shoe shapes, and may be shaped to fit numerous sizes and shapes of asymmetrical shoe lasts. The bootie may shrink to fit, or, alternatively, be stretched to fit, an asymmetrical last having a desired size to form a shoe insert. Such a conformable bootie eliminates the need to have multiple sizes of shoe inserts correlating to particular shoe sizes. In embodiments where the ePTFE is seamless and continuous, the shoe insert eliminates the need for a waterproof seam tape, which is conventionally used to make shoe inserts waterproof. Methods of forming the socks, booties, and shoe inserts are also provided.

What is claimed is: 
     
         1 . A method of forming a seamless bootie comprising:
 applying an adhesive on one of (1) a side of a textile or (2) a side of a conformable expanded polytetrafluoroethylene (ePTFE) tape having an extensibility of at least 1.5× in at least one direction;   positioning said textile on a symmetrical last; and   stretching said conformable ePTFE tape over said textile and said symmetrical last to form a seamless bootie comprising a conformed ePTFE membrane, said adhesive, and said textile.   
     
     
         2 . The method of  claim 1 , wherein said bootie has substantially the shape of said symmetrical last. 
     
     
         3 . The method of  claim 1 , further comprising:
 heating said bootie to a temperature from about 50° C. to about 200° C.   
     
     
         4 . The method of  claim 3 , wherein said symmetrical last is heated with said bootie. 
     
     
         5 . The method of  claim 1 , wherein said ePTFE membrane has a thickness variation from a first location in said bootie to a second location in said bootie of at least 1.2:1. 
     
     
         6 . The method of  claim 1 , wherein said textile possesses at least some elastic properties. 
     
     
         7 . The method of  claim 1 , wherein said textile is selected from the group consisting of a knitted textile tube, a woven textile tube, a tubular sock and a formed sock. 
     
     
         8 . The method of  claim 1 , further comprising heating said bootie to a temperature from about 340° C. to about 375° C. to amorphously lock said ePTFE membrane. 
     
     
         9 . The method of  claim 1 , wherein said stretching step comprises:
 positioning said ePTFE tape over said symmetrical last; and   rotating said symmetrical last through said ePTFE tape to form said bootie.   
     
     
         10 . The method of  claim 1 , wherein said ePTFE membrane has a density greater than about 2.0 g/m 2 . 
     
     
         11 . The method of  claim 1 , wherein at least one of said ePTFE membrane and said textile has at least one additional layer thereon. 
     
     
         12 . The method of  claim 11 , wherein said at least one additional layer is an abrasion resistant coating. 
     
     
         13 . The method of  claim 11 , wherein said at least one additional layer is an oleophobic coating. 
     
     
         14 . The method of  claim 1 , further comprising positioning at least one polymeric overlay on said bootie. 
     
     
         15 . The method of  claim 1 , wherein said textile is affixed to said ePTFE membrane with a discontinuous adhesive. 
     
     
         16 . The method of  claim 1 , wherein said textile is affixed to said ePTFE membrane with a continuous breathable adhesive. 
     
     
         17 . The method of  claim 1 , further comprising attaching at least one second component to said bootie or a portion thereof. 
     
     
         18 . The method of  claim 17 , wherein said at least one second component creates regions in said bootie, at least one of said regions possessing a function or feature different from another said region. 
     
     
         19 . The method of  claim 17 , wherein said at least one second component is selected from the group consisting of a textile, a laminate, a textile laminate, a polymer membrane and a second ePTFE membrane different from said conformed ePTFE membrane. 
     
     
         20 . A method of forming a seamless bootie comprising:
 applying a first adhesive on one of (1) a side of a first textile or (2) a side of a conformable expanded polytetrafluoroethylene (ePTFE) tape having an extensibility of at least 1.5× in at least one direction;   positioning said textile on a symmetrical last;   stretching said conformable ePTFE tape over said first textile and said symmetrical last to form a first composite comprising a conformed ePTFE membrane, said first adhesive, and said first textile;   positioning a second composite comprising a second adhesive and a second textile on said first composite such that said second adhesive is positioned on said conformed ePTFE membrane to form a seamless bootie; and   heating said seamless bootie and said symmetrical last to a temperature from about 50° C. to about 200° C.   
     
     
         21 . The method of  claim 20 , wherein said ePTFE membrane has a thickness variation from a first location in said bootie to a second location in said bootie of at least 1.2:1. 
     
     
         22 . The method of  claim 20 , wherein said first textile and said second textile possess at least some elastic properties. 
     
     
         23 . The method of  claim 20 , wherein said first and second textiles are selected from the group consisting of a knitted textile tube, a woven textile tube, a tubular sock and a formed sock. 
     
     
         24 . The method of  claim 20 , further comprising heating said bootie to a temperature from about 340° C. to about 375° C. to amorphously lock said ePTFE membrane. 
     
     
         25 . The method of  claim 20 , wherein said stretching step comprises:
 positioning said ePTFE tape over said symmetrical last; and   rotating said symmetrical last through said ePTFE tape to form said second composite.   
     
     
         26 . The method of  claim 20 , wherein said ePTFE membrane has a density greater than about 2.0 g/m 2 . 
     
     
         27 . The method of  claim 20 , wherein at least one of said ePTFE membrane, said first textile, and said second textile has at least one additional layer thereon. 
     
     
         28 . The method of  claim 27 , wherein said at least one additional layer is an abrasion resistant coating. 
     
     
         29 . The method of  claim 27 , wherein said at least one additional layer is an oleophobic coating. 
     
     
         30 . The method of  claim 20 , wherein said bootie has a generally symmetrical shape. 
     
     
         31 . The method of  claim 20 , wherein said bootie is breathable. 
     
     
         32 . The method of  claim 20 , wherein said bootie has a moisture vapor transmission rate of at least 3 g/hr. 
     
     
         33 . The method of  claim 20 , wherein said bootie has a moisture vapor transmission rate of at least 5 g/hr. 
     
     
         34 . The method of  claim 20 , wherein said bootie has a moisture vapor transmission rate of at least 10 g/hr. 
     
     
         35 . The method of  claim 20 , wherein said bootie has a moisture vapor transmission rate of at least 20 g/hr. 
     
     
         36 . The method of  claim 20 , wherein said bootie has a moisture vapor transmission rate of at least 30 g/hr. 
     
     
         37 . The method of  claim 20 , wherein said bootie is breathable over its entirety. 
     
     
         38 . The method of  claim 20 , wherein said first textile and said second textile are affixed to said ePTFE membrane with a discontinuous adhesive. 
     
     
         39 . The method of  claim 20 , wherein said first and second textiles are affixed to said ePTFE membrane with a continuous breathable adhesive. 
     
     
         40 . The method of  claim 20 , wherein at least one of said ePTFE membrane, said first textile, and said second textile has thereon a discontinuous adhesive; and
 wherein at least one of said ePTFE membrane, said first textile, and said second textile has thereon a continuous breathable adhesive.   
     
     
         41 . The method of  claim 20 , further comprising attaching at least one second component to said bootie or a portion thereof. 
     
     
         42 . The method of  claim 41 , wherein said at least one second component creates regions in said bootie, at least one of said regions possessing a function or feature different from another said region. 
     
     
         43 . The method of  claim 41 , wherein said at least one second component is selected from the group consisting of a textile, a laminate, a textile laminate, a polymer membrane and a second ePTFE membrane different from said conformed ePTFE membrane. 
     
     
         44 . A method of forming a seamless bootie comprising:
 applying an adhesive to a first side of a textile to form a composite;   positioning said composite on a symmetrical last with said adhesive facing outwardly away from said symmetrical last; and   stretching a conformable ePTFE tape having an extensibility of at least 1.5× in at least one direction over said composite and said symmetrical last to form a seamless bootie comprising an ePTFE membrane, said adhesive, and said textile.   
     
     
         45 . A method of forming a seamless bootie comprising:
 applying an adhesive on one of (1) a side of a textile or (2) a side of a conformable ePTFE tape having an extensibility of at least 1.5× in at least one direction;   positioning said textile on an asymmetrical last;   stretching said conformable ePTFE tape over said textile and said symmetrical last to form a seamless bootie comprising an ePTFE membrane, said adhesive, and said textile.   
     
     
         46 . The method of  claim 45 , wherein said bootie has substantially the shape of said asymmetrical last. 
     
     
         47 . A seamless bootie formed by the method of  claim 1 . 
     
     
         48 . A seamless bootie formed by the method of  claim 20 .