Methods for Through-Fluid Bonding Nonwoven Webs

Abstract

Methods for manufacturing through-fluid bonded continuous fiber nonwoven webs are provided. The method may include providing a through-fluid bonding oven. The through-fluid bonding oven may have a first porous member and a second moving member. An intermediate continuous fiber nonwoven web may be conveyed into the through-fluid bonding oven intermediate the first and second moving porous members. A first surface of the intermediate continuous fiber nonwoven web may be in face-to-face contact with the first porous member. A second surface of the intermediate continuous fiber nonwoven web may be in face-to-face contact with the second porous member. A heated fluid may be flowed through the first and second porous members and the intermediate continuous fiber nonwoven web to create a continuous fiber nonwoven web.

What is claimed is: 
     
         1 . A method of through-fluid bonding an intermediate continuous fiber nonwoven web, the method comprising:
 providing a through-fluid bonding oven;   the through-fluid bonding oven comprising a rotating porous member;   conveying the intermediate continuous fiber nonwoven web into and through the through-fluid bonding oven on the rotating porous member intermediate a surface of the rotating porous member and a porous belt;   flowing a heated fluid through the porous belt, the intermediate continuous fiber nonwoven web, and the rotating porous member; and   using the heated fluid, the porous belt, and the rotating porous member to bond a first surface and a second surface of the intermediate continuous fiber nonwoven web;   wherein the intermediate continuous fiber nonwoven comprises bi-component fibers comprising a first polymer component and a second polymer component, and wherein the first polymer component has a melting temperature that is different than the second polymer component by at least 10 degrees C., but less than 180 degrees C.   
     
     
         2 . The method of  claim 1 , wherein the first polymer component comprises polypropylene and the second polymer component comprises polyethylene. 
     
     
         3 . The method of  claim 1 , wherein the first polymer component comprises polyethylene and the second polymer component comprises polyethylene terephthalate. 
     
     
         4 . The method of  claim 1 , wherein fibers of the intermediate continuous fiber nonwoven web comprise crimped fibers. 
     
     
         5 . The method of  claim 1 , wherein the heated fluid is in the range of about 10 degrees C. to about 280 degrees C. 
     
     
         6 . The method of  claim 1 , wherein the rotating porous member comprises a perforated drum. 
     
     
         7 . The method of  claim 1 , wherein the intermediate continuous fiber nonwoven web intermediate the first porous member and the second porous member has a machine direction strain, and wherein the machine direction strain is less than 1.8%. 
     
     
         8 . The method of  claim 1 , wherein the intermediate continuous fiber nonwoven web intermediate the first porous member and the second porous member has a machine direction strain, and wherein the machine direction strain is negative. 
     
     
         9 . The method of  claim 1 , comprising conveying the intermediate continuous fiber nonwoven web intermediate the rotating porous member and the porous belt at least partially using shear forces. 
     
     
         10 . The method of  claim 1 , wherein the intermediate continuous fiber nonwoven web is not calendar bonded prior to being conveyed into the through-fluid bonding oven. 
     
     
         11 . The method of  claim 1 , wherein the intermediate continuous fiber nonwoven web is intermittently pre-bonded with a heated fluid prior to being conveyed into the through-fluid bonding oven. 
     
     
         12 . The method of  claim 1 , wherein the intermediate continuous fiber nonwoven web is re-entangled prior to being conveyed into the through-fluid bonding oven. 
     
     
         13 . The method of  claim 1 , wherein continuous fibers of the continuous fiber nonwoven web have a denier less than 1.2 decitex. 
     
     
         14 . The method of  claim 1 , comprising cooling the intermediate continuous fiber nonwoven web after or during the flowing a heated fluid step. 
     
     
         15 . A method of through-fluid bonding an intermediate continuous fiber nonwoven web, the method comprising:
 providing a through-fluid bonding oven;   the through-fluid bonding oven comprising a first porous member and a second porous member;   conveying the intermediate continuous fiber nonwoven web into and through the through-fluid bonding oven intermediate the first porous member and the second porous member;   flowing a first heated fluid through the first and second porous members within the through-fluid bonding oven in a first direction in a first zone of the through-fluid bonding oven;   flowing a second heated fluid through the first and second porous members within the through-fluid bonding oven in a second, generally opposite direction in a second zone of the through-fluid bonding oven, wherein the second zone is downstream of the first zone;   using the first heated fluid to force a first surface of the intermediate continuous fiber nonwoven web in the first zone against the first porous member; and   using the second heated fluid to force a second surface of the intermediate continuous fiber nonwoven web in the second zone against the second porous member to create a continuous fiber nonwoven web;   wherein the intermediate continuous fiber nonwoven comprises bi-component fibers comprising a first polymer component and a second polymer component, and wherein the first polymer component has a melting temperature that is different than the second polymer component by at least 10 degrees C., but less than 180 degrees C.   
     
     
         16 . The method of  claim 15 , wherein the first polymer component comprises polypropylene and/or polyethylene, and wherein the second polymer component comprises polyethylene and/or polyethylene terephthalate. 
     
     
         17 . The method of  claim 15 , wherein the first porous member is positioned around first rollers, and wherein the second porous member is positioned around second rollers, the method comprising:
 driving the first porous member around the first rollers; and   driving the second porous member around the second rollers.   
     
     
         18 . The method of  claim 15 , comprising conveying the intermediate continuous fiber nonwoven web intermediate the first and second porous members at least partially using shear forces. 
     
     
         19 . A method of through-fluid bonding an intermediate continuous fiber nonwoven web, the method comprising:
 providing a first through-fluid bonding oven;   the first through-fluid bonding oven comprising a first porous member and a second porous member;   conveying the intermediate continuous fiber nonwoven web into and through the first through-fluid bonding oven intermediate the first porous member and the second porous member;   flowing a first heated fluid through the first and second porous members within the first through-fluid bonding oven in a first direction;   providing a second through-fluid bonding oven;   conveying the intermediate continuous fiber nonwoven web into and through the second through-fluid bonding oven intermediate a third porous member and a fourth porous member;   flowing a second heated fluid through the third and fourth porous members within the second through-fluid bonding oven in a second, generally opposite direction to the first direction, wherein the second through-fluid bonding oven is downstream of the first through-fluid bonding oven;   using the first heated fluid to force a first surface of the intermediate continuous fiber nonwoven web in the first through-fluid bonding oven against the first porous member; and   using the second heated fluid to force a second surface of the intermediate continuous fiber nonwoven web in the second through-fluid bonding oven against the fourth porous member to create a continuous fiber nonwoven web;   wherein the intermediate continuous fiber nonwoven comprises bi-component fibers comprising a first polymer component and a second polymer component, and wherein the first polymer component has a melting temperature that is different than the second polymer component by at least 10 degrees C., but less than 180 degrees C.   
     
     
         20 . The method of  claim 19 , comprising cooling the intermediate continuous fiber nonwoven web after exposure to the first and/or second heated fluids.