Selective placement of absorbent product materials in sanitary napkins and the like

• US 5,817,079 A
• Filed: 02/10/1994
• Issued: 10/06/1998
• Est. Priority Date: 04/07/1989
• Status: Expired due to Term

• Current Assignee: McNeil-PPC Incorporated (Johnson & Johnson)
• Original Assignee: McNeil-PPC Incorporated (Johnson & Johnson)
• Inventors: Jackson, Peter, Srinivasan, Subramanian, Stevenson, Philip, Dabi, Schmuel, DeRossett, Edmund, Bergquist, Roger, Wislinski, Martin, Bradstreet, James A.
• Primary Examiner(s): Clarke, Robert A.
• Application Number:
  US08/195,894
• Time in Patent Office: 1,699 Days
• Field of Search: 604/358, 604/365-368, 604/370, 604/372, 604/378-381, 604/385.1, 428/299, 428/301, 428/481, 428/299.1
• US Class Current: 604/378
• CPC Class Codes: A61F 13/15626 Making fibrous pads without outer layers
• CPC Class Codes: A61F 13/4755 the means being a flat barrier on or inside the absorbent article, e.g. backsheet wrapped around the edges
• CPC Class Codes: A61F 13/4758 the means preventing fluid flow in a longitudinal direction
• CPC Class Codes: A61F 13/535 inhomogeneous in the plane of the pad, e.g. core absorbent layers being of different sizes A61F13/5323, A61F13/537 take precedence
• CPC Class Codes: A61F 13/536 having discontinuous areas of compression
• CPC Class Codes: A61F 13/539 characterised by the connection of the absorbent layers with each other or with the outer layers
• CPC Class Codes: A61F 2013/49074 hourglass; dog bone-shaped
• CPC Class Codes: A61F 2013/51042 with hydrophobic and hydrophilic fibres
• CPC Class Codes: A61F 2013/530233 being thermoplastic fibres
• CPC Class Codes: A61F 2013/53024 being bicomponent fibres
• CPC Class Codes: A61F 2013/530262 only in particular parts or specially arranged
• CPC Class Codes: A61F 2013/530284 the maximum being at a certain depth in the thickness
• CPC Class Codes: A61F 2013/530328 being mineral fibres, e.g. glass
• CPC Class Codes: A61F 2013/530481 having superabsorbent materials, i.e. highly absorbent polymer gel materials
• CPC Class Codes: A61F 2013/53054 the maximum being along the side edges
• CPC Class Codes: Y10T 428/249945 Carbon or carbonaceous fiber
• CPC Class Codes: Y10T 428/249952 At least one thermosetting synthetic polymeric material layer
• CPC Class Codes: Y10T 428/31801 Of wax or waxy material

Abstract

In absorbent products, such as sanitary napkins, discreet areas of dry fibrous materials such as fluid-repellent materials are precisely placed in various planes within the product so as to provide barriers to bodily fluid leakage from the product. In a preferred embodiment, hydrophobic fibers are placed around the periphery of a central absorbent area of an absorbent product to discourage and/or prevent side or end leakage from the product.

Claims

1. An absorbent product comprising a unitized mass of fibers having a body facing side and a garment facing side, said unitized mass of fibers having a discrete bodily fluid-absorbent zone comprising fibers and a bodily fluid repellent zone comprising bodily fluid repellent fibers and disposed at least in part on said body facing side to provide a barrier to bodily fluid leakage;

wherein a sufficient number of said fluid repellent fibers are entangled with a sufficient number of said absorbent zone fibers to join said fluid absorbent and fluid repellent zones.

2. An absorbent product according to claim 1 wherein said fluid absorbent zone is formed at least in part from hydrophilic fibers.

3. An absorbent product according to claim 1 wherein said fluid absorbent zone comprises hydrophilic fibers, and wherein at least one of said zones comprises stabilizing elements caused to adhere to said fibers comprising said zone by the exposure of heat to said stabilizing elements.

4. An absorbent product according to claim 1 wherein said fluid repellent zone comprises a repellent treated fiber blanket having a body facing surface cross-section in the form of a "W", a first side of said W facing toward said body facing side of said product, and wherein said fluid absorbent zone comprises hydrophilic pulp fibers placed on said first side of said "W" to form an essentially planar body facing surface.

5. An absorbent product according to claim 1 which comprises a sanitary napkin.

6. An absorbent product according to claim 1 wherein said fluid repellent zone has a resistance to fluid flow when water is forced through said fluid repellent zone under pressure, said flow resistance being at least 0.02 pounds per square inch of fluid pressure.

7. An absorbent product according to claim 1 wherein said fluid absorbent zone is a first fluid absorbent zone, and further comprising a second fluid absorbent zone formed at least in part from superabsorbent material, said second fluid absorbent zone disposed between said fluid repellent zone and said first fluid absorbent zone so as to act as a flow retardant.

8. An absorbent product according to claim 1 wherein said unitized mass of fibers is vacuum-formed.

9. An absorbent product according to claim 1 which further comprises a barrier applied to the garment facing side of said unitized mass of fibers.

10. An absorbent product according to claim 9 wherein said barrier is applied to side edges of the unitized mass of fibers.

11. An absorbent product according to claim 9 wherein said barrier comprises a sheet of material selected from the group consisting of a polymeric film and a hydrophobically-treated nonwoven fabric.

12. An absorbent product according to claim 1 wherein said discrete bodily fluid-repellent zone is disposed at least in part on the body facing side across longitudinal ends of the product.

13. An absorbent product according to claim 1 wherein said discrete fluid absorbent zone comprises hydrophilic fibers and said discrete fluid repellent zone comprises hydrophobic fibers.

14. An absorbent product according to claim 13 wherein said fluid absorbent zone comprises a lower density, uncompressed section at the body facing side of the product and a compressed higher density section below said uncompressed section on the garment facing side of the product.

15. An absorbent product according to claim 13 further comprising longitudinal edges, and wherein said fluid repellent zone is formed in the shape of wings appended to said longitudinal edges.

16. An absorbent product according to claim 13 wherein said hydrophilic and hydrophobic fibers are visibly differentiated by color.

17. An absorbent product according to claim 13 wherein said fluid repellent zone comprises a continuous layer of hydrophobic fibers having a higher density than said fluid absorbent zone, said layer of hydrophobic fibers being placed on said garment facing side of said product.

18. An absorbent product according to claim 13 wherein said hydrophobic fibers comprise fibers selected from the group consisting of polyester, polyethylene, polypropylene and bicomponent fibers.

19. An absorbent product according to claim 13 wherein said hydrophobic fibers comprise absorbent fibers pretreated to render them substantially repellent to bodily fluids.

20. An absorbent product according to claim 19 wherein said hydrophobic fibers comprise pulp fibers pretreated with a cationic repellent.

21. An absorbent product according to claim 13 wherein said fluid absorbent zone has a periphery, and wherein said fluid repellent zone is disposed so as to surround said periphery of said fluid absorbent zone on said body facing side.

22. An absorbent product according to claim 21 wherein in cross-section said fluid repellant zone extends from the body facing side approximately 50-95% of the height of the product.

23. An absorbent product according to claim 21 wherein said hydrophobic fibers are placed around the periphery of said fluid absorbent zone and in cross-section the height of said repellent zone is approximately 70-80% of the height of the product.

24. An absorbent product according to claim 21 wherein said bodily fluid absorbent zone has a cross-section in the form of an inverted "T" having a narrow topside and a wide bottom side, said narrow top side forming an inner portion and said fluid repellent zone forming an outer peripheral portion of said body-facing side of the product.

25. An absorbent product according to claim 21 wherein said fluid absorbent zone is a first fluid absorbent zone, and further comprising a second fluid absorbent zone formed at least in part from superabsorbent material, said second fluid absorbent zone located between said fluid repellent zone and said first fluid absorbent zone.

26. An absorbent product according to claim 21 wherein at least one of said hydrophobic fibers and said hydrophilic fibers comprises stabilizing elements capable of acquiring adherency by the exposure of heat thereto.

27. An absorbent product according to claim 26 wherein the height of said fluid repellent zone is approximately 100% of the height of the product.

28. An absorbent product according to claim 21 wherein said product is shaped such that at least a portion of said fluid absorbent zone extends above said fluid repellent zone.

29. An absorbent product according to claim 13 which comprises a sanitary napkin.

30. An absorbent product according to claim 29 wherein said hydrophobic fibers are not subject to wetting by fluids having a surface tension greater than about 45 dynes/cm.

31. An absorbent product according to claim 29 in which said hydrophobic fibers comprise pulp fibers treated with cationic repellent, such that said cationic repellent comprises between about 0.19 and about 0.34 weight % of the pulp.

32. An absorbent product according to claim 30 in which said fluid repellent zone comprises a blend of hydrophilic fibers and hydrophobic fibers treated with cationic repellent.

38. The fluid-repellent fibrous material of claim 32 wherein said fibrous material is not subject to wetting by fluids having a surface tension greater than 40 dynes/cm.

33. An absorbent product having a body facing side and a garment facing side, having a discrete fluid absorbent fibrous element and a discrete fluid-repellent fibrous element, made by a process comprising the steps of:

a) contacting one of said discrete fibrous elements with an effective repellent amount of one or more cationic repellents to form the fluid-repellent element; and

b) joining said discrete fluid-repellent fibrous element to said discrete absorbent fibrous element so as to form a unitized structure;

wherein a sufficient number of the fibers of said fluid-repellent fibrous element are entangled with a sufficient number of the fibers of said fluid absorbent fibrous element to join said elements and said fluid-repellent element forms at least a portion of said body facing side.

34. The absorbent product of claim 33 wherein said effective amount of cationic repellent is an amount sufficient to cause said fibrous element to be not subject to wetting by fluids having a surface tension greater than about 45dynes/cm.

35. An absorbent product according to claim 33 wherein the step of joining said discrete fibrous material to said discrete absorbent material comprises vacuum-forming the materials.

36. An absorbent product having a body facing side and a garment facing side, having a discrete fluid absorbent fibrous element and a discrete fluid-repellent fibrous element, made by a process comprising the steps of:

a) contacting a discrete fibrous pulp element with an effective repellent amount of one or more cationic repellents comprising a fatty acid ketene dimer, said effective repellent amount of cationic repellent comprising between about 0.19 and 0.34 weight % based on the total weight of said fibrous pulp element to form said discrete fluid-repellent fibrous element; and

b) joining said discrete fluid-repellent fibrous element to said discrete absorbent fibrous element so as to form a unitized structure;

wherein a sufficient number of the fibers of said fluid-repellent fibrous element are entangled with a sufficient number of the fibers of said fluid absorbent fibrous element to join said elements and said discrete fluid-repellent fibrous element forms at least a portion of said body facing side.

37. A fluid-repellent fibrous material comprising a fibrous material sized with an effective repellent amount of one or more cationic repellents in a sizing treatment, the amount of said cationic repellent utilized in said sizing treatment being such that said fibrous material is not subject to wetting by fluids having a surface tension greater than about 45 dynes/cm.

39. The fluid-repellent fibrous material of claim 37 wherein said effective repellent amount of cationic repellent comprises at least about 0.19 weight % based on the total weight of the fibrous material.

40. The fluid-repellent fibrous material of claim 39 wherein said effective repellent amount of cationic repellent comprises between about 0.19 and 0.34 weight % based on the total weight of the fibrous material.

41. The fluid-repellent fibrous material of claim 39 wherein said fibrous material comprises pulp.

42. The fluid-repellent fibrous material of claim 37 wherein said cationic repellent comprises a fatty acid ketene dimer.

43. The fluid-repellent fibrous material of claim 37 wherein said fibrous material comprises pulp, said cationic repellent comprises a fatty acid ketene dimer, and said effective repellent amount of cationic repellent comprises between about 0.19 and 0.34 weight % based on the total weight Δ

of the fibrous material pulp.

44. The fluid-repellent fibrous material of claim 37 which comprises a blend of fibrous material sized about 0.19 wt-% to about 0.34 wt-% of one or more cationic repellents and absorbent material, the blend of fibrous material not being subject to wetting by fluids having a surface tension greater than about 45 dynes/cm.