Process and apparatus for collecting continuous blow spun fibers

Abstract

The present invention provides a process and apparatus for blow spinning continuous fibers. The novel process utilizes a tensioning device to preclude slack in the fiber. The present invention also provides novel fiber products which utilize continuous fibers prepared by a blow spinning process.

We claim:  
     
         1 . An apparatus for blow spinning continuous fibers comprising: 
 a blow spinning die having at least one capillary for forming a fiber;    means for directing an attenuating gas on said fiber as it exits said capillary;    means for maintaining tension on said fiber following attenuation of said fiber.    
     
     
         2 . The apparatus of  claim 1 , wherein said means for maintaining tension on said fiber is a mechanical device.  
     
     
         3 . The apparatus of  claim 1 , wherein said means for maintaining tension on said fiber is selected from the group consisting of bobbins, rolls and windups.  
     
     
         4 . The apparatus of  claim 3 , additionally comprising: 
 a means for exhausting gases and vapors from said fibers following attenuation of said fibers.    
     
     
         5 . The apparatus of  claim 1 , wherein said means for maintaining tension on said fibers also provides a means for collecting said fibers.  
     
     
         6 . A process for preparing continuous straight blow spun fibers from a mesophase pitch, said process comprising: 
 passing said mesophase pitch through capillaries located within a blow spinning die to form said mesophase pitch into fibers;    attenuating said fibers by contacting said fibers with an attenuating gas;    following attenuation, maintaining sufficient tension on said fibers to preclude the formation of slack.    
     
     
         7 . The process of  claim 6 , wherein said fibers are collected on a receiving device.  
     
     
         8 . The process of  claim 6 , wherein said fibers are collected as either a warp sheet or a traversed continuous filament tow.  
     
     
         9 . The process of  claim 8 , wherein said warp sheet or traversed continuous filament tow is further processed into an unidirectional filament roving fabric.  
     
     
         10 . The process of  claim 6 , wherein prior to collecting said fibers on said receiving device, gases and vapors are removed from said fibers.  
     
     
         11 . The process of  claim 6 , wherein said gases and vapors are removed by cross-flow ventilation applied to the fibers prior to the receiving device.  
     
     
         12 . A process for preparing continuous straight blow spun fibers comprising heating a spinnable substance to a temperature sufficient to allow said substance to flow followed by forming continuous fibers by passing said substance into a spinning die and through capillaries located within said die and attenuating said fibers as they exit the capillary by contacting said fibers with at least one stream of gas wherein the improvement comprises: 
 following attenuation of said fibers, maintaining tension on said fibers by means of a tensioning device.    
     
     
         13 . The process of  claim 12 , additionally including the step of collecting said fibers as a warp sheet or traversed continuous filament tow on a windup device positioned to receive said fibers from said tensioning device.  
     
     
         14 . The process of  claim 13 , including the step of removing gases and vapors prior to collecting said fibers.  
     
     
         15 . The process of  claim 13 , wherein prior to collecting said fibers cross-flow ventilation is applied to the fibers.  
     
     
         16 . A traversed continuous fiber tow comprising continuous fibers prepared by a blow spinning process.  
     
     
         17 . The traversed continuous fiber tow of  claim 16 , wherein said fibers are spun from the group consisting of carbonaceous pitches, polyamides, nylons, polyesters, polypropylenes, polyurethanes, polyaramides and liquid crystalline materials.  
     
     
         18 . A warp sheet comprising continuous fibers prepared by a blow spinning process.  
     
     
         19 . The apparatus of  claim 18 , wherein said means for placing tension on said fiber is selected from the group consisting of bobbins, rolls and windups.  
     
     
         20 . An unidirectional filament roving fabric prepared from continuous fibers prepared by a blow spinning process.  
     
     
         21 . The apparatus of  claim 20 , wherein said means for placing tension on said fiber is selected from the group consisting of bobbins, rolls and windups.