Low density explosion suppressing foams

Abstract

A reticulated polyurethane foam having a density less than 1.0 pounds per cubic foot [16 kg/m 3 ] forms an explosion suppressing material that is installed into the inner volume of a fuel tank to fill from 50 to 90% or up to 100% of the volume of such tank. The reticulated polyurethane foam has particular advantage when used in a fuel tank for an aircraft.

1 . A method for suppressing an explosion in a fuel tank, comprising: 
 installing into the tank a reticulated polyurethane foam having a density less than 1.0 pounds per cubic foot [16 kg/m 3 ].    
     
     
         2 . The method of  claim 1 , wherein the polyurethane foam has a density of from 0.6 to 0.9 pounds per cubic foot [9.6 to 14.4 kg/m 3 ].  
     
     
         3 . The method of  claim 1 , wherein the polyurethane foam has a volume electrical resistivity of less than 10 12  ohm-cm at 70EF [21.1EC].  
     
     
         4 . The method of  claim 1 , wherein the polyurethane foam is reticulated by thermal reticulation.  
     
     
         5 . The method of  claim 1 , wherein the tank has an inner volume and the foam fills from 50 to 90% of the inner volume of the tank.  
     
     
         6 . The method of  claim 1 , wherein the fuel tank is an aircraft fuel tank.  
     
     
         7 . A three dimensional structure for use as an explosion suppressing material in a fuel tank, comprising: 
 a reticulated polyurethane foam prepared by (i) reacting at least one polyester or polyether polyol or a mixture of such polyols and at least one isocyanate compound under foaming conditions to produce a polyurethane foam having a density less than 1.0 pounds per cubic foot [16 kg/m 3 ], and (ii) reticulating said polyurethane foam.    
     
     
         8 . The structure of  claim 7 , wherein the polyurethane foam has a density of from 0.6 to 0.9 pounds per cubic foot [9.6 to 14.4 kg/m 3 ].  
     
     
         9 . The structure of  claim 7 , wherein one or more antistatic agents are added when the polyurethane foam is formed, and the polyurethane foam has a volume electrical resistivity of less than 10 12  ohm-cm at 70EF [21.1EC].  
     
     
         10 . The structure of  claim 7 , wherein the polyurethane foam is reticulated by thermal reticulation.  
     
     
         11 . The structure of  claim 7 , wherein the polyurethane foam is formed under vacuum foaming conditions.