Nonwoven cloth

Abstract

A nonwoven cloth provided with both improved softness and adequate thickness and specific volume having thermally fused composite fibers that are mutually intersecting and overlapping, and a constricted thermally adhesive section in which the thermally fused composite fibers are thermally fused in the intersection region. The constricted thermally adhesive section has a recessed surface facing a center line extending in a direction overlapping with the thermally fused composite fibers across the center of the intersection region. The distance between the thermally fused composite fibers is larger than the sum of the radii of the thermally fused composite fibers, the thickness under a load of 3.0 gf/cm 2 is 0.5-3.0 mm, and the specific volume is 6-300 cm 3 /g.

1 . A nonwoven fabric comprising heat-fusible conjugate fibers intersecting and overlapping with each other and heat-fused constriction parts at the intersection regions of the heat-fusible conjugate fibers,
 wherein when a virtual line extending in the overlapping direction of the heat-fusible conjugate fibers through the center of an intersection region is defined as a center line, the heat-fused constriction parts have a surface which is recessed toward the center line,   wherein the distance between the heat-fusible conjugate fibers that are heat-fused through a heat-fused constriction part is larger than the sum of the fiber radius of each heat-fusible conjugate fiber,   wherein the nonwoven fabric has a thickness of 0.5 to 3.0 mm under a load of 3.0 gf/cm 2  and a specific volume of 6 to 300 cm 3 /g.   
     
     
         2 . The nonwoven fabric according to  claim 1 , wherein the nonwoven fabric has a plurality of heat-fused parts at the intersection regions of the heat-fusible conjugate fibers intersecting and overlapping with each other, and
 wherein the proportion of the number of the heat-fused constriction parts to the total number of the heat-fused parts included in a predetermined region of the nonwoven fabric is 1/10 to 9/10.   
     
     
         3 . The nonwoven fabric according to  claim 1 , wherein the heat-fusible conjugate fibers have a fiber diameter of 10 to 30 μm. 
     
     
         4 . The nonwoven fabric according to  claim 1 , wherein the heat-fusible conjugate fibers comprise a first component and a second component having a melting point lower than that of the first component, and wherein the weight ratio of the second component to the first component is 4/6 to 8/2. 
     
     
         5 . The nonwoven fabric according to  claim 1 , wherein the nonwoven fabric is obtained by a bulkiness restoration treatment of a nonwoven fabric before bulkiness restoration, comprising heat-fused, heat-fusible conjugate fibers, wherein the bulkiness restoration treatment comprises:
 a step of providing a heating chamber having an inlet and an outlet, and   a step of, while conveying the nonwoven fabric before bulkiness restoration so as to enter into the heating chamber through the inlet, to proceed through the heating chamber, and then to exit from the heating chamber through the outlet, feeding a heated fluid at a velocity higher than the conveyance velocity of the nonwoven fabric before bulkiness restoration so as to enter into the heating chamber through one of the inlet and outlet, to proceed through the heating chamber while contacting the nonwoven fabric, and then to exit from the heating chamber through the other of the inlet and outlet.   
     
     
         6 . The nonwoven fabric according to  claim 5 , wherein the nonwoven fabric before bulkiness restoration is an air-through nonwoven fabric obtained by air-through treatment of a web comprising heat-fusible conjugate fibers to heat-fuse the heat-fusible conjugate fibers. 
     
     
         7 . The nonwoven fabric according to  claim 5 , wherein the heated fluid enters into the heating chamber through the inlet and exits from the heating chamber through the outlet. 
     
     
         8 . The nonwoven fabric according to  claim 5 , wherein the nonwoven fabric before bulkiness restoration is conveyed through the heating chamber without being supported. 
     
     
         9 . The nonwoven fabric according to  claim 5 , wherein the heating chamber is defined by two walls that extend from the inlet to the outlet and are separated from each other, and wherein the nonwoven fabric before bulkiness restoration is conveyed within the heating chamber so that both surfaces of the nonwoven fabric before bulkiness restoration respectively continue to face the walls.