High capacity absorbent structure and method for producing same

1. An absorbent core for use in an absorbent article comprising:

a. a stabilized first absorbent layer; and,

b. a second absorbent layer adjacent the first absorbent layer and including (i) absorbent fibers treated with a non-fugitive densification agent and (ii) a superabsorbent material.

2. The absorbent core of claim 1 wherein the first absorbent layer comprises absorbent fibers.

3. The absorbent core of claim 1 wherein the first absorbent layer comprises a superabsorbent.

4. The absorbent core of claim 1 wherein the second absorbent layer has a greater density than the first absorbent layer.

5. The absorbent core of claim 1 wherein in use the first absorbent layer is vertically above the second absorbent layer.

6. The absorbent core of claim 1 wherein in use the first absorbent layer is vertically below the second absorbent layer.

7. The absorbent core of claim 1 wherein the first absorbent layer is a stabilized airlaid absorbent.

8. The absorbent core of claim 7 wherein the first absorbent layer contains from 0 to about 60% superabsorbent.

9. The absorbent core of claim 1 wherein the second absorbent layer has a density of at least about 0.15 g/cc.

10. The absorbent core of claim 1 wherein the second absorbent layer has a density of at least about 0.3 g/cc.

11. The absorbent core of claim 1 wherein non-fugitive densification agent forms hydrogen bonds and is selected from the group consisting of polymeric densification agents, non-polymeric densification agents, and mixtures thereof.

12. The absorbent core of claim 1 wherein non-fugitive densification agent is a high boiling point hydrogen bonding agent.

13. The absorbent core of claim 12 wherein the non-fugitive densification agent is selected from the group consisting of propylene glycol, glycerin, and mixtures thereof.

14. The absorbent core of claim 12 wherein the non-fugitive densification agent is a polymer having a molecular weight between about 4,000 and about 8,000 gm/mole.

15. The absorbent core of claim of claim 12 wherein the non-fugitive densification agent is a polymer having a molecular weight greater than about 8,000 gm/mole.

16. The absorbent core of claim 1 wherein the second absorbent layer contains from about 10% to about 75% superabsorbent.

17. The absorbent core of claim 1 wherein the first absorbent layer and the second absorbent layer have a combined thickness of about 5 millimeters or less.

18. The absorbent core of claim 1 wherein the first absorbent and the second absorbent have a combined thickness of about 2 millimeters or less.

19. The absorbent core of claim 1 wherein the first absorbent layer has a tensile strength of at least about 6 N/50 mm.

20. The absorbent core of claim 19 wherein the first absorbent layer in a dry state has a tensile strength of about 6 N/50 mm.

21. The absorbent core of claim 20 wherein the first absorbent layer in a wet state has a tensile strength of at least about 2 N/50 mm.

22. The absorbent core of claim 19 wherein the second absorbent layer in a dry state has a tensile strength of about 0.5 N/50 mm.

23. An absorbent core for use in an absorbent article comprising:

a. a stabilized first air formed absorbent layer including absorbent fibers such that the first absorbent layer in a dry state has a tensile strength of at least about 6 N/50 mm and in a wet state has a tensile strength of at least about 2 N/50 mm; and,

b. a second absorbent layer adjacent the first absorbent layer and including (i) absorbent fibers treated with a non-fugitive densification agent and (ii) a superabsorbent material wherein the non-fugitive densification agent forms hydrogen bonds and is selected from the group consisting of polymeric densification agents, non-polymeric densification agents, and mixtures thereof.

24. The absorbent core of claim 23 wherein the second absorbent layer has a density greater than a density of the first absorbent layer.

25. The absorbent core of claim 23 wherein the non-fugitive densification agent is selected from the group consisting of propylene glycol, glycerin, and mixtures thereof.

26. The absorbent core of claim 23 wherein the second absorbent layer contains from about 10% to about 75% superabsorbent.

27. The absorbent core of claim 23 wherein the first absorbent layer and the second absorbent layer have a combined thickness of about 5 millimeters or less.

28. The absorbent core of claim 23 wherein in use the first absorbent layer is vertically above the second absorbent layer.

29. The absorbent core of claim 23 wherein in use the first absorbent layer is vertically below the second absorbent layer.

30. An absorbent article comprising:

a. a liner;

b. a baffle;

c. a stabilized first absorbent layer; and,

d. a second absorbent layer adjacent the first absorbent layer and including a superabsorbent material and absorbent fibers treated with a non-fugitive densification agent.

31. The absorbent article of claim 30 wherein the first absorbent layer is vertically below a first side of the liner and the second absorbent layer is vertically below the first absorbent layer.

32. The absorbent article of claim 30 wherein the second absorbent layer is vertically below a first side of the liner and the first absorbent layer is vertically below the second absorbent layer.

33. The absorbent article of claim 30 wherein the first absorbent layer comprises absorbent fibers.

34. The absorbent article of claim 33 wherein the non-fugitive densification agent forms hydrogen bonds and is selected from the group consisting of polymeric densification agents, non-polymeric densification agents, and mixtures thereof.

35. The absorbent article of claim 33 wherein the non-fugitive densification agent is a high boiling point hydrogen bonding agent.

36. The absorbent article of claim 33 wherein the non-fugitive densification agent is selected from the group consisting of propylene glycol, glycerin, and mixtures thereof.

37. The absorbent article of claim 36 wherein the second absorbent layer has a greater density than the first absorbent layer.

38. The absorbent article of claim 36 wherein the second absorbent layer has a density of at least 0.15 g/cc.

39. The absorbent article of claim 36 wherein the second absorbent layer has a density of at least 0.3 g/cc.

40. The absorbent article of claim 30 wherein the second absorbent layer contains from about 10% to about 75% superabsorbent.

41. The absorbent article of claim 30 wherein the first absorbent layer and the second absorbent layer have a combined thickness of about 5 millimeters or less.

42. A process for making an absorbent core comprising:

a. providing a first absorbent material;

b. providing a second material that includes (i) absorbent fibers treated with a non-fugitive densification agent and (ii) a superabsorbent material;

c. cutting the first absorbent material to form a first absorbent layer;

d. placing the first absorbent layer adjacent the second absorbent material; and,

e. cutting the second material to form a second absorbent material to form an absorbent core.

43. The process of claim 42 further comprising:

a. providing a liner; and

b. providing a baffle such that the absorbent core is disposed between the liner and the baffle.

44. The process of claim 43 wherein the absorbent core is disposed such that the liner is adjacent the first absorbent layer.