Process and apparatus for making improved glass micro fibers

Abstract

A process is provided for producing improved, superior and more cost effective glass micro fibers, wherein molten glass in filament form is attenuated into glass micro fibers by gasses of a combusted mixture of air and fuel. The improvement comprises introducing into the mixture a gas stream containing at east 70% by volume of oxygen. This avoids problems in glass micro fiber production where the quality of the fibers varies from time to time, as demonstrated by the quality of paper produced therefrom. An apparatus for producing the fibers is also provided, as well as improved glass micro fibers and improved papers made therefrom.

1 . In a process for producing improved, superior and more cost effective glass micro fibers, wherein molten glass in filament form is attenuated into glass micro fibers by gasses of a combusted mixture of air and fuel, 
 the improvement comprising introducing into the mixture a gas stream containing at least 70% by volume of oxygen.    
   
   
       2 . The process of clam  1 , wherein the gas stream contains at least 75% oxygen.  
   
   
       3 . The process of  claim 2 , wherein the percentage of oxygen is at least 85%.  
   
   
       4 . The process of  claim 3 , wherein the gas stream consists essentially of oxygen.  
   
   
       5 . The process of  claim 4 , wherein the gas stream consists of oxygen.  
   
   
       6 . The process of  claim 1 , wherein the oxygen stream is produced by a packaged oxygen generator.  
   
   
       7 . The process of  claim 1 , wherein the oxygen is introduced into an air stream, which air stream is in turn introduced into the fuel by a sparger.  
   
   
       8 . The process of  claim 7 , wherein the sparger is a swirl-type sparger.  
   
   
       9 . The process of  claim 1 , wherein after introduction of the gas stream containing the oxygen into the mixture, the mixture is between 22 and 35% by volume oxygen.  
   
   
       10 . A fiberizer apparatus for producing improved, superior and more cost effective glass micro fibers, comprising: 
 (1) a premix device ( 12 ) for combining ambient air flowing from an ambient air inlet ( 13 ) and fuel flowing from a fuel inlet ( 14 );    (2) an oxygen analyzer ( 15 ) for analyzing an oxygen content of the combined air and fuel in premix device ( 12 );    (3) an oxygen generator ( 20 ) for generating oxygen and flowing the generated oxygen to the premix device ( 12 ) to form a mixture of oxygen/air/fuel;    (4) a controller( 16 ) for adjusting the flow of oxygen from generator( 20 ) to the premix device( 12 ) in response to signals generated by oxygen analyzer( 15 ) so as to provide the mixture with at least 22% by volume oxygen; and    (5) a burner ( 10 ) for combusting the mixture into a flame in a former tube device ( 21 ) for drawing and attenuating primary filaments ( 4 ) of molten glass into glass micro fibers ( 22 ).    
   
   
       11 . The apparatus of  claim 10 , wherein the flow of oxygen from generator ( 20 ) is introduced into the ambient air flowing into premix device ( 12 ).  
   
   
       12 . The apparatus of  claim 11 , wherein the flow of oxygen is introduced into the ambient air by a sparger ( 25 ).  
   
   
       13 . The apparatus of  claim 12 , wherein the sparger is a swirl-type sparger.  
   
   
       14 . The apparatus of  claim 10 , wherein the oxygen generator is a packaged oxygen generator.  
   
   
       15 . The apparatus of  claim 14 , wherein the packaged oxygen generator is near the fiberizer apparatus.  
   
   
       16 . Improved glass micro fibers which can be formed into a paper with at least a 16% better tensile strength.  
   
   
       17 . The fibers of  claim 16 , which can be formed into a paper with at least a 28% increased double fold tensile strength.  
   
   
       18 . A paper made of the fibers of  claim 16 .  
   
   
       19 . A paper made of the fibers of  claim 17.