Multilayer web with extensible and inextensible regions and methods of making same
View Patent ↗A multi-layered web is provided that includes an elastic web bonded to an inelastic web. The inelastic web has extensible and inextensible regions arranged along the machine direction. In the extensible regions, the inelastic web is bonded to the elastic web in a creped structure that is extensible by virtue of the creping. A continuous process is provided to manufacture a multi-layer web having extensible regions that are conjoined with regions that are inextensible by varying the tension that is applied during manufacture of the multi-layer web. The apparatus comprises an elastic web that is fed into a bonding nip, into which one or more inelastic webs are also provided. The elastic web is fed into the bonding nip under a tension that is alternated between a low value that is sufficient to ensure processing stability, and a higher value that provides an elongation to the elastic web. During the low tension phase of the bonding process the inextensible region is formed in the multi-layer web due to the inextensibility of the web.
1. A method for manufacturing a multi-layer web, comprising;
feeding first and second webs along a machine direction to a bonding station, the second web being elastic; and
bonding the first and second webs to one another at the bonding station while alternately increasing and decreasing tension in said second web to create extensible regions corresponding to areas where the first and second webs are bonded together while the second web was stretched and inextensible regions corresponding to areas where the first and second webs are bonded together while the second web was not stretched, wherein the extensible and inextensible regions are arranged along the machine direction.
2. The method of claim 1 , wherein the second web is alternately gripped and released between a pair of rollers located upstream of the bonding station, the rollers traveling at a circumferential speed that differs from a speed at which the first web is fed to the bonding station.
3. The method of claim 1 , wherein alternately increasing and decreasing tension in the second web comprises changing a speed at which the second web is fed to the bonding station.
4. The method of claim 1 , wherein alternately increasing and decreasing tension in the second web comprises gripping the second web with a cam roller that is driven in and out of a feed path along which the second web travels through a staging area.
5. The method of claim 1 , wherein the bonding comprises one of thermal bonding, mechanical bonding, adhesive lamination, chemical bonding, ultrasonic bonding and any combination thereof.