Ultrasonic bonding process for bonding nonwoven webs containing cellulose ester fibers

Abstract

Process for ultrasonically bonding nonwoven webs comprising: providing a nonwoven web comprised of base fibers in an amount from 0 to 85 wt % and binder fibers in an amount from 15 to 100 wt %, based on the total weight of the nonwoven web; and ultrasonically bonding the nonwoven web to itself or another nonwoven web, wherein the binder fibers comprise cellulose ester fibers.

What we claim is: 
     
         1 . A process for bonding nonwoven webs comprising:
 a) providing a nonwoven web comprised of base fibers in an amount from 0 to 85 wt % and binder fibers in an amount from 15 to 100 wt %, based on the total weight of the nonwoven web; and   b) ultrasonically bonding the nonwoven web to itself,   wherein the binder fibers comprise cellulose ester fibers.   
     
     
         2 . The process according to  claim 1 , wherein the binder fibers comprise 80 wt % or more of cellulose acetate fibers. 
     
     
         3 . The process according to  claim 1 , wherein the binder fibers are 100 wt % cellulose acetate fibers. 
     
     
         4 . The process according to  claim 1 , wherein the base fibers comprise non-thermoplastic cellulose fibers. 
     
     
         5 . The process according to  claim 1 , wherein the base fibers comprise 80 wt % or more of non-thermoplastic cellulose fibers. 
     
     
         6 . The process according to  claim 1 , wherein the ultrasonic bonding forms a seam having a breaking strength that is at least 40% of the breaking strength of a single-stitch seam. 
     
     
         7 . A process for bonding nonwoven webs comprising:
 a) providing a first nonwoven web comprised of first base fibers in an amount from 0 to 85 wt % and first binder fibers in an amount from 15 to 100 wt %, based on the total weight of the first nonwoven web; and   b) ultrasonically bonding the first nonwoven web to itself or to a second nonwoven web comprised of second base fibers and second binder fibers, wherein the first binder fibers comprise cellulose ester fibers.   
     
     
         8 . The process according to  claim 7 , wherein the first binder fibers comprise 80 wt % or more of cellulose acetate fibers. 
     
     
         9 . The process according to  claim 7 , wherein the first base fibers comprise non-thermoplastic cellulose fibers. 
     
     
         10 . A process for bonding nonwoven webs comprising:
 a) providing a first nonwoven web comprised of first base fibers in an amount from 0 to 85 wt % and first binder fibers in an amount from 15 to 100 wt %, based on the total weight of the first nonwoven web; and   b) ultrasonically bonding the first nonwoven web to a second nonwoven web comprised of second base fibers and second binder fibers, wherein the first binder fibers comprise cellulose ester fibers.   
     
     
         11 . The process according to  claim 10 , wherein the first binder fibers comprise 80 wt % or more of cellulose acetate fibers. 
     
     
         12 . The process according to  claim 10 , wherein the first base fibers comprise non-thermoplastic cellulose fibers. 
     
     
         13 . The process according to  claim 10 , wherein the second nonwoven web comprises second base fibers in an amount from 0 to 85 wt % and second binder fibers in an amount from 15 to 100 wt %, based on the total weight of the second nonwoven web. 
     
     
         14 . The process according to  claim 10 , wherein the second binder fibers comprise cellulose ester fibers. 
     
     
         15 . The process according to claim  21 , wherein the second binder fibers comprise 80 wt % or more of cellulose acetate fibers. 
     
     
         16 . The process according to  claim 10 , wherein the second base fibers comprise 80 wt % or more of non-thermoplastic cellulose fibers. 
     
     
         17 . The process according to  claim 10 , wherein the process further comprises forming a laminate of said first and second nonwoven webs. 
     
     
         18 . The process according to  claim 17 , wherein the laminate is not formed using an adhesive and does not comprise an adhesive. 
     
     
         19 . The process according to  claim 18 , wherein the laminate is formed by bonding said first and second nonwoven webs using only ultrasonic bonding. 
     
     
         20 . The process according to  claim 17 , wherein the laminate is biodegradable and compostable.