Thin rotary-fiberized glass insulation and process for producing same

Abstract

A rotary fiberglass needled glass insulation product is provided. The formation of the needled insulation product may be conducted in a continuous in-line process in which the fibers are rotary formed, a binder is sprayed onto the hot fibers, the fibers are collected onto a conveyor and formed into a fiberglass pack, the fiberglass pack is passed through the oven, and the cured insulation blanket is passed through the needling apparatus. The needled insulation product may have a thickness of less than about 0.75 inches. The reduction in thickness and increased density caused by the needling process permits the production of lower thickness and higher density final insulation products. Thin insulation products made in accordance with the present invention can be manufactured using current manufacturing lines, thereby saving time and money. The needled insulation product may be utilized in household appliances, water heaters, and HVAC equipment.

1 . A needled rotary glass insulation product comprising: 
 a plurality of single component rotary glass fibers, at least a portion of said single component rotary glass fibers being entangled and mechanically bonded; and    a binder applied to at least a portion of said single component rotary glass fibers.    
     
     
         2 . The needled rotary glass insulation product of  claim 1 , wherein said insulation product has a thickness of about 0.75 inches or less.  
     
     
         3 . The needled rotary glass insulation product of  claim 2 , wherein said insulation product has a thickness of about 0.5 inches or less.  
     
     
         4 . The needled rotary glass insulation product of  claim 2 , wherein said binder is a low formaldehyde binder.  
     
     
         5 . The needled rotary glass insulation product of  claim 4 , wherein said binder is at least one member selected from the group of a polycarboxylic based binder, a polyacrylic acid glycerol binder and a polyacrylic acid triethanolamine binder.  
     
     
         6 . The needled rotary glass insulation product of  claim 2 , wherein said insulation product has a density of from about 1 pcf to about 10 pcf.  
     
     
         7 . The needled rotary glass insulation product of  claim 6 , wherein said insulation product has a density of from about 3 pcf to about 5 pcf.  
     
     
         8 . A method of forming a needled rotary glass insulation product having a reduced thickness comprising the steps of: 
 rotary-fiberizing single component glass fibers to form single component glass fibers having random lengths;    applying a binder to at least a portion of said glass fibers;    collecting said at least partially coated glass fibers to form an insulation pack;    passing said insulation pack through an oven to at least partially cure said binder on said glass fibers and form an insulation blanket; and    needling said insulation blanket to a predetermined thickness to form said needled rotary glass insulation product.    
     
     
         9 . The method of  claim 8 , further comprising the step of: 
 blowing said glass fibers downward to form a veil of said fibers prior to applying said binder to said glass fibers.    
     
     
         10 . The method of  claim 8 , wherein said needling step comprises: 
 pushing needles in a downward and upward motion through said insulation blanket to entangle said glass fibers and impart mechanical strength and integrity to said insulation blanket.    
     
     
         11 . The method of  claim 8 , further comprising the step of: 
 compressing said fiberglass pack in said oven between upper and lower compression rollers prior to needling said insulation blanket.    
     
     
         12 . The method of  claim 11 , further comprising the step of: 
 rolling said needled rotary glass insulation product onto a creel for shipping or storage.    
     
     
         13 . The method of  claim 11 , further comprising the steps of: 
 cutting said needled insulation product into a predetermined shape; and    packaging said cut insulation product for shipping or storage.    
     
     
         14 . The method of  claim 8 , wherein said predetermined thickness is a thickness of less than or equal to about 0.75 inches.  
     
     
         15 . A gas fired water heater comprising: 
 a generally cylindrical body having a top surface and a bottom surface interconnected by a vertical side outer wall;    an internal water tank having thereon a needled rotary glass insulation product, said needled rotary glass insulation product including: 
 a plurality of single component rotary glass fibers, at least a portion of said single component rotary glass fibers being entangled and mechanically bonded; and  
 a binder applied to at least a portion of said single component rotary glass fibers;  
   a combustion chamber including a burner;    at least one air flow intake penetrating said side outer wall; and    at least one airflow passageway positioned between said outer wall and said needled rotary glass insulation product to provide oxygen to ignite said burner and produce a flame to heat water stored in said internal water tank, said at least one air flow passageway connecting said combustion chamber and said at least one air flow intake.    
     
     
         16 . The gas fired water heater of  claim 15 , further comprising a fire-retarding barrier layer positioned on said needled rotary glass insulation product.  
     
     
         17 . The gas fired water heater of  claim 16 , wherein said at least one air flow intake penetrates said outer wall at least about 18 inches from the floor.  
     
     
         18 . The gas fired water heater of  claim 15 , wherein said needled rotary glass insulation product has a thickness of about 0.75 inches or less.  
     
     
         19 . The gas fired water heater of  claim 18 , wherein said needled rotary glass insulation product has a density of from about 1 pcf to about 10 pcf.  
     
     
         20 . The gas fired water heater of  claim 18 , wherein said binder is at least one member selected from the group of a phenol-formaldehyde binder, a urea-formaldehyde binder, a polycarboxylic based binder, a polyacrylic acid glycerol binder and a polyacrylic acid triethanolamine binder.