Thin insulative material with layered gas-filled cellular structure

Abstract

A lightweight, gas-filled, highly insulative material is incorporated into an article of outdoor gear or apparel (e.g., a camping pad). The insulative material has a layered cellular structure that can be filled with an insulative gas (e.g., air or argon). The insulative material includes two or more layers of cells, which improves insulation (compared to a single layer) by reducing convection for a given thickness. Increasing the thickness without substantially increasing convection results in a better insulator and an improvement in the ability to retain heat.

1 . A layered insulative material incorporated into an article of outdoor gear or apparel, comprising:
 first and second gas impermeable layers joined together to form a chamber having a cell structure comprising a plurality cells that are in fluid communication; and   one or more interior layers of material positioned within the chamber between the first and second gas impermeable layers, the one or more interior layers dividing the chamber into the plurality of cells, wherein the plurality of cells form a first layer of cells above a second layer of cells; and   a valve mechanism coupled to the insulative material and configured to allow inflation and deflation of the plurality of cells of the first and second layers of cells.   
     
     
         2 . An insulative material as in  claim 1 , wherein the cell volume is in a range from about 0.25 cm 3  to about 2000 cm 3 . 
     
     
         3 . An insulative material as in  claim 1 , wherein the cell volume is in a range from about 0.25 cm 3  to about 1000 cm 3 . 
     
     
         4 . An insulative material as in  claim 1 , wherein the cell volume is in a range from about 2 cm 3  to about 300 cm 3 . 
     
     
         5 . An insulative material as in  claim 1 , wherein the first and second gas impermeable layers include a woven material. 
     
     
         6 . An insulative material as in  claim 5 , wherein each of the gas impermeable layers includes a gas impermeable laminate material. 
     
     
         7 . An insulative material as in  claim 6 , wherein the gas impermeable laminate material is selected from the group consisting of polyethylene, polypropylene, polyurethane, urethane, silicone rubber, latex rubber, polytetrafluoroethylene (PTFE), expanded PTFE, butyl rubber, and Mylar. 
     
     
         8 . An insulative material as in  claim 1  further comprising welding a portion of the first and seconds gas impermeable layers together to form the chamber. 
     
     
         9 . An insulative material as in  claim 8 , wherein the welding forms seams that at least partially defines the cells of the plurality of cells. 
     
     
         10 . An article of outdoor gear or apparel including an insulative material as in  claim 1 , the article further comprising a dry gas reservoir configured to allow a dry insulating gas to be introduced into the plurality of cells. 
     
     
         11 . An article of outdoor gear or apparel as in  claim 10 , wherein the dimensions of the plurality of cells are such that the Rayleigh value of the dry insulating gas within the plurality of cells is less than 300,000 for each cell. 
     
     
         12 . An article of outdoor gear or apparel as in  claim 10 , wherein the dry insulating gas is dry atmospheric air having a moisture content less than about 4 percent by weight. 
     
     
         13 . An article of outdoor gear or apparel as in  claim 10 , wherein the dry insulating gas is selected from the group consisting of argon, krypton, xenon, carbon dioxide, sulfur hexafluoride, and combinations thereof. 
     
     
         14 . An article of outdoor gear or apparel as in  claim 10 , wherein the insulative material is incorporated into a coat, a parka, a jacket, a vest, a pant, a glove, a mitten, a hat, a liner, a wader, a boot, a tent, a sleeping bag, a bivouac bag, or a sleeping pad. 
     
     
         15 . A method for using an article of outdoor gear or apparel, comprising:
 providing an article of outdoor gear or apparel according to the method of  claim 10 ; and   filling the plurality of cells with a dry insulating gas selected from the group consisting of atmospheric air, argon, krypton, xenon, carbon dioxide, sulfur hexafluoride, and combinations thereof, wherein the insulating gas has a moisture content less than about 4 percent by weight.   
     
     
         16 . A layered insulative material incorporated into an article of outdoor gear or apparel, comprising:
 an insulative material including first and second gas impermeable layers joined together to form a chamber having a cell structure comprising a plurality cells that are in fluid communication; and   one or more interior layers of material positioned within the chamber between the first and second gas impermeable layers, the one or more interior layers dividing the chamber into the plurality of cells, wherein the plurality of cells form a first layer of cells above a second layer of cells,
 the first layer of cells including seams between the cells of the first layer; 
 the second layer of cells including seams between the cells of the second layer; 
 wherein at least a portion of the cells of the first layer of cells overlap with a portion of the seams of the second layer of cells; and 
 wherein at least a portion of the cells of the second layer of cells overlap with a portion of the seams of the first layer of cells; and 
   a valve mechanism coupled to the insulative material and configured to allow inflation and deflation of the plurality of cells of the first and second layers of cells.   
     
     
         17 . An insulative material as in  claim 16 , wherein the first and second gas impermeable layers are woven. 
     
     
         18 . A sleeping pad incorporating a layered insulative material, comprising:
 a sleeping surface sized and configured to support a person lying thereon; and   a layered insulative material comprising,
 first and second gas impermeable layers joined together to form a chamber having a cell structure comprising a plurality cells that are in fluid communication; and 
 one or more interior layers of material positioned within the chamber between the first and second gas impermeable layers, the one or more interior layers dividing the chamber into the plurality of cells, wherein the plurality of cells form a first layer of cells above a second layer of cells; and 
   a valve mechanism coupled to the insulative material and configured to allow inflation and deflation of the plurality of cells of the first and second layers of cells.   
     
     
         19 . A sleeping pad as in  claim 18 , wherein,
 the first layer of cells includes seams between the cells of the first layer;   the second layer of cells includes seams between the cells of the second layer;   at least a portion of the cells of the first layer of cells overlap with a portion of the seams of the second layer of cells; and   at least a portion of the cells of the second layer of cells overlap with a portion of the seams of the first layer of cells.   
     
     
         20 . A sleeping pad as in  claim 19 , wherein the first and second gas impermeable layers are woven. 
     
     
         21 . A sleeping pad as in  claim 18 , wherein certain regions of the camping pad have different sized cells compared to other regions of the camping pad. 
     
     
         22 . A sleeping pad as in  claim 21 , wherein the average thickness of the cells in a region of the sleeping pad configured to support the torso portion of a person is thicker than a region of the sleeping pad configured to support the legs of a person.