Patent ID: 7803248

Claim:
In a system for making a permeable, fibrous nonwoven mat comprising glass fibers bound together with a resinous binder having a dry permeability of at least about 100 cubic feet/square foot/minute comprising a permeable carrier for the wet, fibrous nonwoven mat, an oven for removing water or a solvent from the wet fibrous nonwoven mat by heating the fibrous nonwoven mat and water or solvent with hot gases at a pressure of less than about 18 inches of water column to volatilize the water or solvent to produce a dry fibrous nonwoven mat and one or more burners for producing hot gases, the improvement comprising an electrical generating system comprising a heat engine and one or more ducts for carrying waste hot gases having a temperature of 390 degrees C. or higher and a pressure of less than 18 inches of water column from a source that includes the electrical generating system comprising the heat engine, driven by hot, high pressure, gases, and/or hot waste gases from a glass melting furnace to the oven to replace all or a part of the hot gases normally supplied by one or more combustion burners, to remove the water or solvent from the wet, fibrous nonwoven mat to form a dried fibrous nonwoven mat and to heat the dried fibrous nonwoven mat to a temperature in the range of 105 to 260 degrees C. to cure the resinous binder.