System and method for incorporating graphics into absorbent articles

1. A method for incorporating graphics into absorbent articles, the method comprising:

providing a moving substrate to a print cylinder;

sensing a line speed reference signal from a line speed target machinery component comprising the main drive, said line speed reference signal being generated by an encoder that measures the angular velocity of the main drive;

rotating the print cylinder at a predetermined speed, based on the line speed reference signal, to thereby print a series of graphics on the moving substrate at a predetermined distance frequency;

sensing a phase difference signal from a phase target machinery component; and

setting an actual print cylinder phase angle, based on the phase difference signal, to approximate a predetermined phase angle to thereby position the series of graphics on the moving substrate at a series of desired graphics locations.

2. The method of claim 1 , wherein the substrate comprises a backsheet web.

3. The method of claim 2 , wherein the method further comprises:

providing a supply of absorbent pads;

providing a topsheet web;

joining the topsheet web to the backsheet web with the absorbent pads located therebetween to thereby form an absorbent core assembly; and

cutting the absorbent core assembly at a series of cuts with a cutter;

wherein the phase target machinery component comprises the cutter.

4. The method of claim 1 , wherein the phase target machinery component comprises a cutter.

5. The method of claim 1 , wherein the line speed target machinery component and the phase target machinery component comprise different machinery components.

6. The method of claim 1 , wherein the line speed target machinery component and the phase target machinery component comprise the same machinery component.

7. The method of claim 1 , wherein the phase difference signal is generated by an inductance sensor.

8. The method of claim 1 , wherein the series of graphics comprises a series of wetness indicators.

9. The method of claim 1 , wherein the series of graphics comprises a series of combined wetness indicators and decorative graphics.

10. The method of claim 1 , wherein the print cylinder comprises a flexographic print cylinder.

11. The method of claim 1 , wherein the method further comprises:

providing the moving substrate to a second print cylinder; and

rotating the second print cylinder at the predetermined speed, to thereby print a second series of graphics on the moving substrate at the predetermined distance frequency.

12. The method of claim 11 , wherein the series of graphics comprises a series of wetness indicators and the second series of graphics comprises a series of decorative graphics.

13. The method of claim 1 , wherein the method further comprises:

detecting a shutdown mode from the line speed reference signal;

disengaging the print cylinder from the substrate; and

rotating the print cylinder at an idle speed.

14. The method of claim 1 , wherein the method further comprises:

detecting a startup mode from the line speed reference signal;

accelerating the print cylinder from an idle speed to the predetermined speed; and

engaging the print cylinder with the moving substrate.

15. A method for incorporating graphics into absorbent articles, the method comprising:

providing a moving substrate to a graphic applicator;

sensing a line speed reference signal from a line speed target machinery component comprising the main drive, said line speed reference signal being generated by an encoder that measures the angular velocity of the main drive;

rotating the graphic applicator at a predetermined speed, based on the line speed reference signal, to thereby apply a series of graphics on the moving substrate at a predetermined distance frequency;

sensing a phase difference signal from a phase target machinery component; and

setting an actual graphic applicator phase angle, based on the phase difference signal, to approximate a predetermined phase angle to thereby position the series of graphics on the moving substrate at a series of desired graphics locations.

16. The method of claim 15 , wherein the substrate comprises a backsheet web.

17. The method of claim 16 , wherein the method further comprises:

providing a supply of absorbent pads; providing a topsheet web;

joining the topsheet web to the backsheet web with the absorbent pads located therebetween to thereby form an absorbent core assembly; and

cutting the absorbent core assembly at a series of cuts with a cutter;

wherein the phase target machinery component comprises the cutter.

18. The method of claim 15 , wherein the phase target machinery component comprises a cutter.

19. The method of claim 15 , wherein the line speed target machinery component and the phase target machinery component comprise different machinery components.

20. The method of claim 15 , wherein the line speed target machinery component and the phase target machinery component comprise the same machinery component.

21. The method of claim 15 , wherein the phase difference signal is generated by an inductance sensor.

22. The method of claim 15 , wherein the series of graphics comprises a series of wetness indicators.

23. The method of claim 15 , wherein the series of graphics comprises a series of combined wetness indicators and decorative graphics.

24. The method of claim 15 , wherein the graphic applicator is a cut-and-space device.

25. The method of claim 15 , wherein the method further comprises:

detecting a shutdown mode from the line speed reference signal; and

disengaging the graphic applicator from the substrate.

26. The method of claim 15 , wherein the method further comprises:

detecting a startup mode from the line speed reference signal;

accelerating the graphic applicator to the predetermined speed; and

engaging the graphic applicator with the moving substrate.