Flexible laminate structure

Abstract

A flexible non-porous laminate film structure is provided comprising a textile substrate having a fluorinated film laminated thereto, which is laminated at a temperature lower than the softening point of the predominant polymeric component of the fluoropolymer fiber. The resulting product is resistant to delamination.

1 . A flexible, non-porous laminate film structure comprising a woven or knit textile substrate formed of fluoropolymer fibers, and at least one fluoropolymer film layer, wherein the fluoropolymer film layer is intimately bonded to the textile substrate and material from the fluoropolymer film layer fills voids between at least some of the fibers of the substrate. 
     
     
         2 . The laminate film structure as in  claim 1  wherein the film wets out during the lamination process. 
     
     
         3 . The laminate film structure as in  claim 1  wherein material from the fluoropolymer film layer within voids between fibers of the substrate is visible under SEM magnification. 
     
     
         4 . The laminate film structure as in  claim 1  wherein the fibers of the textile substrate initially have a round cross-section, and wherein the fibers of the textile substrate are transfused into an amorphous mass and the round cross-sections of the fibers are morphed into geometries suitable for filling interstitial voids in the textile structure, as is visible under SEM magnification. 
     
     
         5 . The laminate film structure as in  claim 1  that is prepared without surface etching of the film. 
     
     
         6 . The laminate film structure as in  claim 1  that is prepared without intermediary dispersions or glues, fibrils or nodes, or similar interconnecting paths on or in the surface of the fluoropolymer film conventionally used to create strong adhesion between substrate and film. 
     
     
         7 . The laminate film structure as in  claim 1  that is prepared in the absence of fillers. 
     
     
         8 . The laminate film structure as in  claim 1  that is prepared in the absence of cooling processing steps other than ambient to fixate the lamination for dimensional stability. 
     
     
         9 . The laminate film structure of  claim 1  that is laminated at a temperature lower than the softening point of the predominant polymeric component of the fluoropolymer fiber. 
     
     
         10 . The laminate film structure of  claim 1  that is laminated between 310° C. and 325° C., under steady pressure of at least 20 bars at a speed of 0.5 m/min to 6.5 m/min. 
     
     
         11 . The laminate film structure of  claim 1  that is laminated between 310° C. and 325° C., under steady pressure of at 30-50 bars for approximately 10 seconds. 
     
     
         12 . The laminate film structure of  claim 1 , wherein the textile substrate comprises fluoropolymer fibers that are at least 75% by weight poytetrafluoroethylene and 25% by weight polyfluoroalkoxy. 
     
     
         13 . The laminate film structure of  claim 12 , wherein the ratio of poytetrafluoroethylene to polyfluoroalkoxy is 3 to 1. 
     
     
         14 . The laminate film structure of  claim 12 , wherein the film is wholly or predominately polyfluoroalkoxy or poytetrafluoroethylene. 
     
     
         15 . The laminate film structure of  claim 1  in which the film is laminated on one or both sides of the substrate. 
     
     
         16 . The laminate film structure of  claim 1  wherein the textile substrate is a woven or knit fabric. 
     
     
         17 . A conveyor belt composed of the laminate film structure of  claim 1 . 
     
     
         18 . A flexible duct composed of the laminate film structure of  claim 1 . 
     
     
         19 . An expansion joint composed of the laminate film structure of  claim 1 . 
     
     
         20 . The laminate film structure of  claim 1  wherein the textile substrate is formed from fluoroploymer fibers comprising a blend of poytetrafluoroethylene material and polyfluoroalkoxy material. 
     
     
         21 . The laminate film structure of  claim 20  wherein the fluoroploymer fibers provide two softening points. 
     
     
         22 . The laminate film structure of  claim 21  wherein the two softening points include one at about 305° C. for the polyfluoroalkoxy material and another at about 330° C. for the poytetrafluoroethylene material.