Moisture repellent air duct products

Abstract

Water-resistant fibrous air duct insulation products and methods for making such products. The products may include a duct board or a duct tube including a first layer of resin-bonded fibrous mat having a second layer of durable, preferably non-woven, facing material adhered thereto, wherein the facing material defines the air stream surface for the board or tube. The duct board or tube is preferably rendered water-repellent at the air stream surface by incorporating a hydrophobic agent into the adhesive used to adhere the second layer to the first layer.

What is claimed is:  
     
         1 . An insulated air duct product comprising: 
 a first layer formed from fibrous material bound with a resin binder; and    a facing layer adhered to a surface of said first layer by an adhesive containing an effective amount of hydrophobic agent to render the product essentially impermeable to water and resistant to aqueous solutions not exceeding about 20% by volume of isopropyl alcohol.    
     
     
         2 . The product of  claim 1  wherein said adhesive comprises said binder and said hydrophobic agent.  
     
     
         3 . The product of  claim 2  wherein said effective amount of hydrophobic agent is present in said adhesive in a ratio of about 1:20 to 1:200 hydrophobic agent to binder.  
     
     
         4 . The product of  claim 1  wherein said hydrophobic agent is selected from the group consisting of silicone, oil, fluorocarbon and waxes.  
     
     
         5 . The product of  claim 1  wherein said first layer is rigid.  
     
     
         6 . The product of  claim 1  wherein the product is a duct board.  
     
     
         7 . The product of  claim 1  wherein the product is a duct tube.  
     
     
         8 . A method for making an insulated air duct product, said method comprising the steps of: 
 (a) providing a first layer formed from fibrous material bound with a resin binder; and    (b) adhering a facing layer to a surface of said first layer by an adhesive containing an effective amount of hydrophobic agent to render the product essentially impermeable to water and resistant to aqueous solvent solutions not exceeding about 20% by volume of solvent.    
     
     
         9 . The method of  claim 8  wherein said adhesive comprises said binder and said hydrophobic agent.  
     
     
         10 . The method of  claim 9  wherein said effective amount of hydrophobic agent is present in said adhesive in a ratio of about 1:20 to 1:200 hydrophobic agent to binder.  
     
     
         11 . The method of  claim 8  wherein said hydrophobic agent is silicone, oil, fluorocarbon and waxes.  
     
     
         12 . The method of  claim 8  wherein said first layer is rigid.  
     
     
         13 . The method of  claim 8  wherein the product is a duct board.  
     
     
         14 . The method of  claim 8  wherein the product is a duct tube.  
     
     
         15 . A water-repellent adhesive comprising: 
 a curable resin; and    a hydrophobic agent.    
     
     
         16 . The adhesive of  claim 15  wherein said effective amount of hydrophobic agent is present in said adhesive in a ratio of about 1:20 to 1:200 hydrophobic agent to resin.