Fluid pouch with inner microstructure

Abstract

Disclosed is a pouch (also called a flexible container) for holding fluid, the pouch including: (a) a first polymeric sheet including a first inner body and a first outer surface, the first inner body including a first inner surface and inner microstructure extending from the first inner surface, the first inner body defining an aerial microstructure surface area density (AMSAD) between 5% and 15%; (b) a second polymeric sheet including a second inner surface and a second outer surface. The second polymeric sheet may be joined with the first polymeric sheet such that the first inner body and the second inner surface form an air-tight fluid chamber therebetween. The second polymeric sheet may lack microstructure extending from the second inner surface. The first inner surface, the first outer surface, the second inner surface, and the second outer surface may be smooth and non-recessed.

We claim: 
     
         1 . A method of manufacturing a fluid container, the method comprising:
 producing a first polymeric sheet comprising a first inner body and a flat and smooth first outer surface, the first inner body comprising a flat and smooth first inner surface and semi-spherical microstructure, the step of producing the first polymeric sheet comprising:
 placing a mass of polymeric material into a mold, the mold defining a plurality of semi-spherical recesses arranged in an array; 
 heating the mass of polymeric material, in the mold, at least until the mass of polymeric material flows into the semi-spherical recesses; 
 cooling the mass polymeric material and removing the cooled mass of polymeric material from the mold; 
   heating a perimeter of the first polymeric sheet to join the perimeter of the first polymeric sheet with a second polymeric sheet, the second polymeric sheet comprising a flat and smooth second inner surface and a flat and smooth second outer surface;   wherein during the step of heating the perimeter of the first polymeric sheet, the semi-spherical microstructure of the first polymeric sheet face the second inner surface of the second polymeric sheet.   
     
     
         2 . The method of  claim 1 , wherein the polymeric material has a melting temperature and the step of heating the mass of polymeric material, in the mold comprises heating the mass of polymeric material to a maximum temperature, the maximum temperature being less than the melting temperature. 
     
     
         3 . The method of  claim 1 , wherein a first gap, being defined between adjacent columns of the array of semi-spherical recesses is equal to a second gap, being defined between adjacent rows of the array of semi-spherical recesses. 
     
     
         4 . The method of  claim 3 , wherein each of the semi-spherical recesses defines a radius and centers of adjacent semi-spherical recesses are separated by a pitch. 
     
     
         5 . The method of  claim 4 , wherein a ratio of the radius to the pitch is between 7:100 and 30:100. 
     
     
         6 . The method of  claim 4 , wherein a ratio of the radius to the pitch is between 10:100 and 20:100 and the second polymeric sheet is non-microstructured.