Heat generating packaging material

Abstract

A heat generating packaging material is disclosed for packaging of temperature sensitive materials, the heat generating packaging material militating against damage to the heat sensitive material by maintaining a temperature in the packaging within a predetermined range.

1 . A heat generating packaging material comprising: 
 a heating agent; and    an air-permeable covering enclosing the heating agent, the covering having an air permeability per unit time of between 10000 and 25000 sec/100 cc resulting in a reaction of the heating agent lasting up to 48 hours.    
   
   
       2 . The packaging material according to  claim 1 , further comprising a backing material disposed on at least a portion of the covering.  
   
   
       3 . The packaging material according to  claim 2 , wherein the backing material is cardboard.  
   
   
       4 . The packaging material according to  claim 1 , wherein the packaging material is adapted to form a shipping container.  
   
   
       5 . The packaging material according to  claim 4 , wherein an outer surface of the shipping container includes a plurality of apertures formed therein.  
   
   
       6 . The packaging material according to  claim 4 , wherein the shipping container is an envelope.  
   
   
       7 . The packaging material according to  claim 4 , wherein the shipping container is a box.  
   
   
       8 . The packaging material according to  claim 1 , wherein the heating agent includes at least one of metal powder, water, water-retaining agent, activated carbon, and salt.  
   
   
       9 . The packaging material according to  claim 8 , wherein the water-retaining agent is wood flour.  
   
   
       10 . The packaging material according to  claim 1 , wherein generation of heat by the heating agent lasts between 24 and 48 hours.  
   
   
       11 . The packaging material according to  claim 8 , wherein the metal powder is iron powder.  
   
   
       12 . The packaging material according to  claim 1 , wherein the heating agent includes by weight 55-65% metal powder, 18-22% of water, 9-11% water-retaining agent, 3.5-4.5% activated carbon, 4.5-6% salt.  
   
   
       13 . The heat packet according to  claim 1 , wherein the air-permeable covering includes a coating applied thereto.  
   
   
       14 . A heat generating packaging material comprising: 
 a heating agent consisting essentially of metal powder, water, water-retaining agent, activated carbon, and salt; and    an air-permeable covering enclosing the heating agent, the covering having an air permeability per unit time of between 10000 and 25000 sec/100 cc resulting in a reaction of the heating agent lasting up to 48 hours.    
   
   
       15 . The packaging material according to  claim 14 , further comprising a backing material disposed on at least a portion of the covering.  
   
   
       16 . The packaging material according to  claim 14 , wherein the packaging material is adapted to form a shipping container.  
   
   
       17 . A method of maintaining a desired temperature in a shipping package comprising the steps of: 
 providing a heat generating packaging material having a heating agent disposed in an air-permeable covering, the covering having an air permeability per unit time of between 10000 and 25000 sec/100 cc resulting in a reaction of the heating agent lasting up to 48 hours; and    disposing the heat generating packaging material in the shipping package to maintain the package within the desired temperature range.    
   
   
       18 . The method according to  claim 17 , further comprising the steps activating a chemical reaction by exposing the air-permeable bag to oxygen and of reducing oxygen exposure to the air-permeable bag by sealing the shipping package by any conventional means.  
   
   
       19 . The method according to  claim 17 , further comprising the steps providing a backing material and disposing the backing material on at least a portion of the covering.  
   
   
       20 . The method according to  claim 17 , further comprising the steps forming the shipping package into a desired shape.