Apparatus for making a high loft, non-woven web exhibiting excellent recovery

Abstract

An apparatus for making a high loft, non-woven web exhibiting excellent recovery is disclosed. The web has a 3-dimensional structure with fibers oriented in the x, y and z directions. The apparatus includes a die having 2 to 20 rows of nozzles with each row containing a plurality of nozzles. A pair of moving surfaces is located from a distal end of each nozzle. The pair of moving surfaces form a convergent passage. A pair of heaters is used to heat each of the pair of moving surfaces. A plurality of filaments are deposited onto the pair of moving surfaces and are routed through the convergent passage to form a 3-dimensional structure having two thin outer skins.

We claim: 
     
         1 . An apparatus for producing a high loft, non-woven web, said web having a 3-dimensional structure with fibers oriented in the x, y and z directions, said apparatus comprising:
 a) a die having 2 to 20 rows of nozzles, each row containing a plurality of nozzles each ejecting a filament, and each of said plurality of nozzles having a distal end;   b) a pair of moving surfaces located from between about 10 cm to about 150 cm of said distal end of each of said plurality of nozzles, and said pair of moving surfaces forming a convergent passage having an entry and an exit;   c) a pair of heaters each associated with one of said pair of moving surfaces, said pair of heaters capable of heating said pair of moving surfaces to an elevated temperature;   d) depositing means for depositing said plurality of filaments, free of any additional fibers, onto and between said pair of moving surfaces; and   e) routing means for causing said plurality of filaments to pass through said convergent passage from said entry to said exit to form a 3-dimensional structure.   
     
     
         2 . The apparatus of  claim 1  wherein said pair of moving surfaces comprise a first rotatable drum and a second rotatable drum, and said heated surfaces on said first and second rotatable drums create a thin outer skin on opposite major surfaces of said web, and each of said thin outer skins is less than about 2.5 millimeters in thickness. 
     
     
         3 . The apparatus of  claim 2  wherein said first rotatable drum rotates counterclockwise and said second rotatable drum rotates clockwise, and both drums cause said plurality of filaments to move in a machine direction. 
     
     
         4 . The apparatus of  claim 1  wherein said pair of moving surfaces comprise a first conveyor belt and a second conveyor belt, and said non-woven web has a basis weight of from between about 20 to about 600 grams per square meter. 
     
     
         5 . The apparatus of  claim 1  wherein said pair of heaters heat said pair of moving surfaces to an elevated temperature which is less than the melting temperature of said polymer. 
     
     
         6 . The apparatus of  claim 12  wherein said of heaters heat said pair of moving surfaces to an elevated temperature ranging from between about 180° F. to about 300° F. 
     
     
         7 . The apparatus of  claim 4  wherein said first conveyor belt moves counterclockwise and said second conveyor belt moves clockwise, both of said first and second conveyor belts cause said plurality of filaments to move in a machine direction, said first and second conveyor belts are aligned at an angle to one another, and both of said first and second conveyor belts are heated to an elevated temperature. 
     
     
         8 . The apparatus of  claim 7  wherein said first and second conveyor belts converge toward one another at a point farthest away from said distal end of each of said plurality of nozzles. 
     
     
         9 . The apparatus of  claim 8  wherein said first and second conveyor belts converge toward one another at an angle of less than 45 degrees. 
     
     
         10 . An apparatus for producing a high loft, non-woven web, said web having a 3-dimensional structure with fibers oriented in the x, y and z directions, said apparatus comprising:
 a) a die connected to an extruder and having 2 to 20 rows of nozzles, each row containing a plurality of nozzles each ejecting a filament formed from a single polymer, and each of said plurality of nozzles having a distal end;   b) a pair of rotatable drums located within from about 10 cm to about 150 cm of said distal end of each of said plurality of nozzles, said pair of rotatable drums forming a convergent passage having an entry and an exit, and each of said pair of rotatable drums having a patterned surface;   c) a pair of heaters each associated with one of said pair of rotatable drums, said pair of heaters capable of heating said pair of rotatable drums to an elevated temperature;   d) depositing means for depositing said plurality of filaments, free of any additional fibers, onto and between said pair of rotatable drums; and   e) routing means for causing said plurality of filaments to pass through said convergent passage from said entry to said exit to form a 3-dimensional structure.   
     
     
         11 . The apparatus of  claim 10  wherein said convergent passage has a nip of greater than about 0.5 cm, and said heated surfaces on said first and second rotatable drums create a thin outer skin on opposite major surfaces of said web, and each of said thin outer skins is less than about 2.5 millimeters in thickness. 
     
     
         12 . The apparatus of  claim 11  wherein said pair of heaters heat said pair of rotatable drums to an elevated temperature which is less than the melting temperature of said polymer. 
     
     
         13 . The apparatus of  claim 12  wherein said pair of heaters heat said pair of rotatable drums to an elevated temperature ranging from between about 180° F. to about 300° F. 
     
     
         14 . The apparatus of  claim 11  wherein said first rotatable drum rotates counterclockwise and said second rotatable drum rotates clockwise, and both drums causing said plurality of continuous filaments to move in a machine direction. 
     
     
         15 . An apparatus for producing a high loft, non-woven web from a single polymer, said web having a 3-dimensional structure with fibers oriented in the x, y and z directions, said apparatus comprising:
 a) a die connected to an extruder and having 2 to 20 rows of nozzles, each row containing a plurality of nozzles each ejecting a filament formed from a single polymer, and each of said plurality of nozzles having a distal end;   b) a pair of conveyor belts located within from about 10 cm to about 150 cm of said distal end of each of said plurality of nozzles, said pair of conveyor belts forming a convergent passage having an entry and an exit;   c) a pair of heaters each associated with one of said pair of conveyor belts, said pair of heaters capable of heating said pair of conveyor belts to an elevated temperature;   d) depositing means for depositing said plurality of filaments, free of any additional fibers, onto said pair of conveyor belts;   e) routing means for causing said plurality of filaments to pass through said convergent passage from said entry to said exit to form a 3-dimensional structure; and   f) a spray located downstream of and in vertical alignment with said pair of conveyor belts for adding an additive to said 3-dimensional structure to create a high loft, non-woven web with said filaments transformed into fibers oriented in the x, y and z directions, said web having a thickness of less than about 200 mm, a basis weight ranging from between about 100 g/m2 to about 2,000 g/m2, and a vertical cross-section of said web, when taken parallel to a machine direction, exhibiting a plurality of snugly stacked, approximately V, U or C-shaped structures, with each V, U or C-shaped structure having an apex facing in said machine direction, and said web having a recovery value ranging from between about 50% to about 80% after being compressed under a pressure of 0.25 psi for a time period of 30 minutes.   
     
     
         16 . The apparatus of  claim 15  wherein said convergent passage has a nip of greater than about 0.5 cm, and said heated surfaces on said first and second rotatable drums create a thin outer skin on opposite major surfaces of said web, and each of said thin outer skins is less than about 2.5 millimeters in thickness. 
     
     
         17 . The apparatus of  claim 16  wherein said pair of conveyor belts are aligned at an angle to one another, and said pair of heaters heat said pair of conveyor belts to an elevated temperature which is less than the melting temperature of said polymer. 
     
     
         18 . The apparatus of  claim 16  wherein said pair of conveyor belts converge toward one another at a point farthest away from said distal end of each of said plurality of nozzles, and said pair of heaters heat said pair of conveyor belts to an elevated temperature ranging from between about 180° F. to about 300° F. 
     
     
         19 . The apparatus of  claim 16  wherein said pair of conveyor belts converge toward one another at an angle of less than 60 degrees, and said non-woven web has a basis weight of from between about 20 to about 600 grams per square meter. 
     
     
         20 . The apparatus of  claim 16  wherein said pair of conveyor belts converge toward one another at an angle of less than 45 degrees.