Method for perforating a nonlinear line of weakness

1. A method for providing a nonlinear line of weakness on a web material, the method comprising the steps of:

providing a counter component comprising a nonlinear shape, wherein the nonlinear shape has a shape width (W);

providing a blade in operative relationship with the counter component and comprising a plurality of teeth;

rotating at least one of the blade and the counter component into interacting relationship with the other of the blade and the counter component;

feeding a web between the counter component and the blade such that while in interacting relationship the blade cooperates with the counter component to perforate the web, wherein the web is moving in a machine direction; and

reciprocally shifting one of the counter component and the blade for a distance (D) in a shifting direction.

2. The method of claim 1 wherein the rotating step comprises rotating the counter component.

3. The method of claim 1 further comprising the step of rotating the at least one of the blade and the counter component out of interacting relationship with the other of the blade and the counter component.

4. The method of claim 1 wherein the nonlinear shape is periodic and comprises a wavelength, and the shape width (W) is substantially equivalent to the wavelength.

5. The method of claim 1 wherein the counter component comprises an anvil.

6. The method of claim 1 wherein the counter component is disposed on a cylindrical base having a base longitudinal axis about which the cylindrical base rotates, and wherein the counter component is helically mounted on the cylindrical base at an angle of greater than 0 degrees to about 45 degrees to the base longitudinal axis.

7. The method of claim 1 further comprising providing a linear actuator and the reciprocally shifting step further comprises reciprocally shifting the one of the counter component and the blade using the linear actuator.

8. The method of claim 1 wherein the shifting direction is at angle θ with respect to the cross machine direction.

9. The method of claim 1 further comprising the step of creating a movement profile to control the manner of reciprocally shifting, wherein the movement profile comprises one of the group of an acceleration profile, a deceleration profile, a velocity profile, a dwell position, a dwell duration, a distance profile, a position versus time profile, a shift position versus interaction position profile and combinations thereof.

10. A method for providing a nonlinear line of weakness on a web material, the method comprising the steps of:

providing a blade comprising a nonlinear shape, wherein the nonlinear shape has a shape width (W);

providing a counter component in operative relationship with the blade and comprising a plurality of teeth;

rotating at least one of the blade and the counter component into interacting relationship with the other of the blade and the counter component;

feeding a web between the counter component and the blade such that while in interacting relationship the blade cooperates with the counter component to perforate the web, wherein the web is moving in a machine direction; and

reciprocally shifting one of the counter component and the blade for a distance (D) in a shifting direction.

11. The method of claim 10 wherein the rotating step comprises rotating the blade.

12. The method of claim 10 further comprising the step of rotating the at least one of the blade and the counter component out of interacting relationship with the other of the blade and the counter component.

13. The method of claim 10 wherein the counter component comprises an anvil.

14. The method of claim 10 further comprising providing a linear actuator and the reciprocally shifting step further comprises reciprocally shifting the one of the counter component and the blade using the linear actuator.

15. The method of claim 10 wherein the shifting direction is at an angle θ with respect to the cross machine direction.

16. The method of claim 10 wherein the one of the counter component and the blade is disposed on a cylinder having a longitudinal axis and the shifting direction is substantially parallel to the longitudinal axis.

17. A method for providing a nonlinear line of weakness on a web material, the method comprising the steps of:

providing a shaped component comprising a nonlinear shape having a shape width (W);

providing a toothed component in operative relationship with the shaped component, wherein the toothed component comprises a plurality of teeth;

rotating at least one of the toothed component and the shaped component into interacting relationship with the other of the toothed component and the shaped component;

feeding a web between the toothed component and the shaped component such that while in interacting relationship the toothed component cooperates with the shaped component to perforate the web, wherein the web is moving in a first direction;

reciprocally shifting the shaped component for a distance (D 1 ) in a second direction; and

reciprocally shifting the toothed component for a distance (D 2 ), in a third direction.

18. The method of claim 17 wherein the rotating step comprises rotating the shaped component.

19. The method of claim 17 further comprising the step of rotating the at least one of the blade and the counter component out of interacting relationship with the other of the blade and the counter component.

20. The method of claim 17 further comprising the step of creating a movement profile to control the manner of reciprocally shifting, wherein the movement profile comprises one of the group of an acceleration profile, a deceleration profile, a velocity profile, a dwell position, a dwell duration, a distance profile, a position versus time profile, a shift position versus interaction position profile and combinations thereof.