Elastic strand coating process

Abstract

A method for applying fluids to a strand and useable for bonding adhesive coated strands to substrates in the production of bodily fluid absorbing hygienic articles, by drawing the strand along an isolated path, moving a fluid or adhesive fiber back and forth across a path of the strand as the fluid fiber is dispensed toward the strand, and capturing substantially all of the fluid fiber on the isolated strand, and in some applications contacting an adhesive coated strand with the substrate to bond the strand thereto. The adhesive fiber is vacillated back and forth across a path of the strand beyond opposing sides thereof to at least partially coat all sides thereof with adhesive. In bodily fluid absorbing hygienic articles, the methods substantially eliminate fabric stiffening and loss of moisture absorbing capacity thereof, provide substantially uniformly bonding along the axial dimension of the strand to ensure uniform bunching of fabrics, optimum fluid absorption, and comfort.

What is claimed is:  
     
         1 . A method for applying adhesive to a strand, and useable for bonding the strand to a substrate in the production of bodily fluid absorbing hygienic articles, the method comprising: 
 drawing the strand along a path separated spatially from the substrate;    dispensing an adhesive fiber toward the strand;    capturing substantially all of the adhesive fiber on the strand when the strand is spatially separated from the substrate; and    contacting the adhesive coated strand with the substrate to bond the strand to the substrate.    
     
     
         2 . The method of  claim 1  further comprising moving the adhesive fiber back and forth across the path of the strand as the adhesive fiber is dispensed toward the strand.  
     
     
         3 . The method of  claim 1  further comprising dispensing a substantially continuous adhesive fiber toward the strand, and moving the adhesive fiber back and forth across the path of the strand as the adhesive fiber is dispensed toward the strand.  
     
     
         4 . The method of  claim 1 , the strand is an elastic strand and the substrate is a fabric for a bodily fluid absorbing hygienic article, the method further comprising stretching the elastic strand before the elastic strand is bonded to the substrate.  
     
     
         5 . The method of  claim 1 , the adhesive fiber is a hot melt adhesive dispensed from an adhesive orifice of a meltblowing nozzle, the method further comprising vacillating the adhesive fiber back and forth across the path of the strand with first and second air flows dispensed from first and second air orifices disposed on opposing sides of the adhesive orifice.  
     
     
         6 . The method of  claim 5  further comprising controlling the amplitude and frequency of vacillation of the adhesive fiber with the first and second air flows to capture substantially all of the adhesive fiber by the strand.  
     
     
         7 . The method of  claim 5  further comprising controlling the amplitude and frequency of vacillation of the adhesive fiber with the first and second air flows so that the strand is coated substantially uniformly with adhesive along an axial dimension of the strand.  
     
     
         8 . The method of  claim 5  further comprising dispensing the adhesive from above the strand, and spatially separating the strand from the substrate by a distance greater than a droop distance of the adhesive fiber below the strand opposite from where the adhesive fiber is dispensed from above the strand.  
     
     
         9 . The method of  claim 6  further comprising: 
 drawing a plurality of at least two strands;  
 dispensing a plurality of adhesive fibers from a corresponding plurality of adhesive orifices of the nozzle toward a corresponding one of the plurality of strands;  
 vacillating the plurality of adhesive fibers back and forth across the path of the corresponding strand with a plurality of corresponding first and second air flows dispensed from first and second air orifices disposed on opposing sides of the plurality of adhesive orifices;  
 each strand capturing substantially all of the adhesive fiber dispensed from the corresponding adhesive orifice when the strand is spatially separated from the substrate to substantially uniformly coat the strand with adhesive; and  
 contacting the plurality of adhesive coated strands with the substrate to bond the plurality of strands to the substrate.  
 
     
     
         10 . The method of  claim 9  further comprising dispensing the corresponding plurality of air flows from the corresponding plurality of air orifices arranged in series with the corresponding plurality of adhesive orifices.  
     
     
         11 . The method of  claim 9  further comprising dispensing at least two adjacent adhesive fibers from corresponding adhesive orifices offset axially relative to each other along the path of the strand.  
     
     
         12 . The method of  claim 1 , the adhesive fiber is a hot melt adhesive, the method further comprising dispensing the adhesive fiber from a spiral nozzle in a swirling pattern to move the adhesive fiber back and forth across the path of the strand as the adhesive fiber is dispensed toward the strand.  
     
     
         13 . A method for applying fluid to a strand, and useable for bonding the strand to a substrate in the production of bodily fluid absorbing hygienic articles, the method comprising: 
 drawing the strand along an isolated path;    dispensing a fluid fiber toward the strand;    moving the fluid fiber back and forth across a path of the strand as the fluid fiber is dispensed toward the strand;    capturing substantially all of the fluid fiber on the strand; and    coating all sides of the strand at least partially with fluid.    
     
     
         14 . The method of  claim 13  further comprising moving the fluid fiber back and forth across a path of the strand beyond opposing sides of the strand as the fiber is dispensed toward the strand to coat all sides of the strand at least partially with fluid.  
     
     
         15 . The method of  claim 14 , the fluid is adhesive, the method further comprising: 
 drawing the strand along a path separated spatially from a substrate;    dispensing an adhesive fiber from above the strand;    moving the adhesive fiber back and forth across the path of the strand as the adhesive fiber is dispensed toward the strand;    capturing substantially all of the adhesive fiber on the strand when the strand is spatially separated from the substrate;    coating all sides of the strand at least partially with adhesive when the strand is spatially separated from the substrate; and    contacting the adhesive coated strand with the substrate to bond the strand to the substrate.    
     
     
         16 . The method of  claim 15 , the strand is an elastic strand and the substrate is a fabric for a bodily fluid absorbing hygienic article, the method further comprising stretching the elastic strand before bonding the elastic strand to the substrate.  
     
     
         17 . The method of  claim 15  further comprising spatially separating the strand from the substrate by a distance greater than a droop distance of the adhesive fiber below the strand opposite from where the adhesive fiber is dispensed from above the strand.  
     
     
         18 . The method of  claim 15  the adhesive fiber is a hot melt adhesive, the method further comprising dispensing the adhesive fiber from a spiral nozzle in a swirling pattern to move the adhesive fiber back and forth across the path of the strand beyond opposing sides of the strand as the adhesive fiber is dispensed toward the strand.  
     
     
         19 . The method of  claim 15  further comprising bonding the adhesive coated strand to a second substrate, whereby the strand is disposed between the substrate and the second substrate.  
     
     
         20 . The method of  claim 15 , the adhesive fiber is a hot melt adhesive dispensed from an adhesive orifice of a meltblowing nozzle, the method further comprising vacillating the adhesive fiber back and forth across the path of the strand beyond opposing sides of the strand with first and second air flows dispensed from first and second air orifices disposed on opposing sides of the adhesive orifice.  
     
     
         21 . The method of  claim 20  further comprising controlling the amplitude and frequency of vacillation of the adhesive fiber with the first and second air flows so that substantially all of the adhesive fiber is captured by the strand.  
     
     
         22 . The method of  claim 20  further comprising controlling the amplitude and frequency of vacillation of the adhesive fiber with the first and second air flows so that the strand is coated substantially uniformly with adhesive along an axial dimension of the strand.  
     
     
         22 . The method of  claim 20  further comprising: 
 drawing a plurality of at least two strands;  
 dispensing a plurality of adhesive fibers from a corresponding plurality of adhesive orifices toward a corresponding one of the plurality of strands;  
 vacillating the plurality of adhesive fibers back and forth across the path of the corresponding strand and beyond opposing sides of the strand with a plurality of corresponding first and second air flows disposed on opposing sides of the plurality of adhesive orifices;  
 each strand capturing substantially all of the adhesive fiber dispensed from the corresponding adhesive orifice when the strand is spatially separated from the substrate;  
 at least partially coating all sides of each strand with adhesive when the plurality of strands are spatially separated from the substrate; and  
 contacting the plurality of adhesive coated strands with the substrate to bond the plurality of strands to the substrate.  
 
     
     
         23 . The method of  claim 22  further comprising dispensing the corresponding plurality of air flows from the corresponding plurality of air orifices arranged in series with the corresponding plurality of adhesive orifices.  
     
     
         24 . The method of  claim 22  further comprising dispensing at least two adjacent adhesive fibers from corresponding adhesive orifices offset axially relative to each other along the path of the strand.