Method of modifying a nonwoven fibrous web for use as component of a disposable absorbent article

A method for modifying a pre-formed, nonwoven fibrous web, said method comprising the steps of:

• a. feeding in a web movement direction to a first pair of opposed, interengaged forming rolls a substantially untensioned, nonwoven fibrous web having an initial width, an initial thickness, an initial basis weight, an initial low-elongation cross-web extensibility expressed as an initial load to achieve 10% cross-web elongation, an initial intermediate-elongation cross-web extensibility expressed as an initial load to achieve 30% cross-web elongation, an initial cross-web strength, and an initial elongation capability;
• b. gripping the web between the first pair of interengaged forming rolls at a nip defined by the forming rolls, wherein each forming roll includes a plurality of axially spaced, circumferentially extending, alternating radials teeth and intervening grooves, and wherein the teeth of one roll are opposite from and extend into the grooves of the opposed roll;
• c. modifying the nonwoven web by subjecting the nonwoven web to incremental lateral stretching as the web passes between the first pair of interengaged forming rolls and as the rolls rotate in opposite directions, to incrementally stretch the web in a cross-web direction that is substantially perpendicular to the web movement direction and withdrawing the web from between the first pair of interengaged forming rolls by applying to the web a tensile withdrawal force that extends in the web movement direction;
• d. feeding in a web movement direction to a second pair of opposed, interengaged forming rolls;
• e. gripping the web between the second pair of interengaged forming rolls at a nip defined by the forming rolls, wherein each forming roll includes a plurality of axially spaced, circumferentially extending, alternating radial teeth and intervening grooves, and wherein the teeth of one roll are opposite from and extend into the grooves of the opposed roll;
• f. further modifying the nonwoven web by subjecting the nonwoven web to incremental lateral stretching as the web passes between the second pair of interengaged forming rolls and as the rolls rotate in opposite directions, to incrementally stretch the web in a cross-web direction that is substantially perpendicular to the web movement direction and withdrawing the web from between the second pair of interengaged forming rolls by applying to the web a tensile withdrawal force that extends in the web movement direction, wherein the resulting further modified web has a load to achieve 10% elongation of from about 5% to about 100% of the initial load to achieve 10% elongation, a load to achieve 30% elongation of from about 5% to about 100% of the initial load to achieve 30% elongation, a cross-web strength of from about 10% to about 70% of the initial cross-web strength, and a cross-web elongation capability of from about 105% to about 200% of the initial cross-web elongation capability.

A method for forming a composite elastic material having a modified nonwoven component and an elastic component, said method comprising the steps of:

• a. feeding in a web movement direction to a first pair of opposed, interengaged forming rolls a substantially untensioned, preformed, nonwoven fibrous web having an initial elongation capability;
• b. gripping the web between the first pair of interengaged forming rolls at a nip defined by the forming rolls, wherein each forming roll includes a plurality of axially spaced, circumferentially extending, alternating radial teeth and intervening grooves, and wherein the teeth of one roll are opposite from and extend into the grooves of the opposed roll;
• c. modifying the nonwoven web by subjecting the nonwoven web to incremental lateral stretching as the web passes between the first pair of interengaged forming rolls and as the rolls rotate in opposite directions, to incrementally stretch the web in a cross-web direction that is substantially perpendicular to the web movement direction and withdrawing the web from between the first pair of interengaged forming rolls by applying to the web a tensile withdrawal force that extends in the web movement direction, wherein the modified web has a cross-web elongation capability of from about 50% to about 200% of the initial cross-web elongation capability;
• d. joining an elastic web to the modified nonwoven web to form a composite elastic material.