Absorbent article having an ideal core distribution and method of preparing same

• US 6,717,029 B2
• Filed: 03/06/2001
• Issued: 04/06/2004
• Est. Priority Date: 03/06/2001
• Status: Expired due to Term

• Current Assignee: Paragon Trade Brands, LLC
• Original Assignee: Paragon Trade Brands Inc. (Johnson Controls International plc)
• Inventors: Baker, Andrew
• Primary Examiner(s): Lo, Weilun
• Assistant Examiner(s): Kidwell, Michele
• Application Number:
  US09/799,071
• Publication Number:
  US 20030023215A1
• Time in Patent Office: 1,127 Days
• Field of Search: 604/358, 604/367, 604/374, 604/375, 604/378, 604/380, 604/385.01
• US Class Current: 604/378
• CPC Class Codes: A61F 13/15203 Properties of the article, e.g. stiffness or absorbency chemical aspects A61L15/00
• CPC Class Codes: A61F 13/532 inhomogeneous in the plane of the pad
• CPC Class Codes: A61F 13/5323 having absorbent material located in discrete regions, e.g. pockets

Abstract

An absorbent article and a method for preparing an absorbent article is disclosed. The absorbent article has a core comprised of pulp, a polymer or a combination thereof. The absorbent article conforms to a certain Distribution Index (DI) or a certain Distribution Index (DI) profile that confers one or more superior properties to the core and in turn to the absorbent article, such as superior absorbency efficiency and superior cost efficiency. The method for preparing the absorbent article uses DI values (e.g., DI_max, DI_min, DI_male and DI_female) or a DI profile as design parameters for providing absorbent articles having one or more superior characteristics.

Claims

1. An absorbent article comprising:

a core comprised of pulp, a polymer or a combination thereof;

wherein the core has a maximum Distribution Index (DI_max) of at least about 6,000 g/m3;

and

wherein the DI_max is the maximum DI(i,j,) value on said absorbent article, said (DI_i,j) being determined according to Formula I;

$\begin{array}{cc}D<br><br>\text{\hspace{1em}<br><br>}<br><br>I_{\left(i,j\right)}<br><br>\left(\frac{g}{m^2}\right)=\frac{100<br><br>\left(\frac{\mathrm{cm}}{m}\right)}{N}<br><br>\underset{T=1}{\overset{N}{\sum <br><br>}}<br><br>\frac{B<br><br>\text{\hspace{1em}<br><br>}<br><br>W_T}{\left(D<br><br>\text{\hspace{1em}<br><br>}<br><br>i<br><br>\text{\hspace{1em}<br><br>}<br><br>s<br><br>\text{\hspace{1em}<br><br>}<br><br>t_T+7.62\right)}& \left(I\right)\end{array}$

 

by using the Baker Method.

2. The absorbent article of claim 1, wherein the DI_max is at least about 6,500 g/m³.

3. The absorbent article of claim 1, wherein the DI_max is at least about 7,000 g/m³.

4. The absorbent article of claim 1, wherein the DI_max is at least about 7,500 g/m³.

5. The absorbent article of claim 1, wherein the core is comprised of about 10% to about 90% by weight of particulate or fibrous SAP.

6. The absorbent article of claim 1, wherein the core is comprised of about 20% to about 80% by weight of particulate or fibrous SAP.

7. The absorbent article of claim 1, wherein the core is comprised of about 40% to about 70% by weight of particulate or fibrous SAP.

8. The absorbent article of claim 1, wherein the core has a minimum Distribution Index (DI_min) of about 2,800 g/m³ to about 3,600 g/m³.

9. The absorbent article of claim 1, wherein the core has a minimum Distribution Index (DI_min) of about 2,900 g/m³ to about 3,300 g/m³.

10. The absorbent article of claim 1, wherein the core has a minimum Distribution Index (DI_min) of about 2,950 g/m³ to about 3,200 g/m³.

11. The absorbent article of claim 1, wherein the core has a Distribution Index _i,j (DI_i,j) at −

5,0 of at least about 5,750 g/m³.

12. The absorbent article of claim 1, wherein the core has a Distribution Index _i,j (DI_i,j) at 0,0 of at least about 6,000 g/m³.

13. The absorbent article of claim 1, wherein the core has a Distribution Index _i,j (DI_i,j) at 5,0 of at least about 5,750 g/m³.

14. The absorbent article of claim 1, wherein the core has a Distribution Index _i,j (DI_i,j) at 10,0 of at least about 4,250 g/m³.

15. The absorbent article of claim 1, wherein the core has a Distribution Index _i,j (DI_i,j) at 15,0 of at least about 3,250 g/m³.

16. The absorbent article of claim 1, wherein the core has a Distribution Index _i,j (DI_i,j) of at least 5,500 g/m³ at each point along a centerline of the core from −

5,0 to 5,0.

17. The absorbent article of claim 1, wherein the DI_max corresponds to a section of the core between 0,0 and 5,0.

18. An absorbent article comprising:

a core comprised of pulp, a polymer or a combination thereof;

wherein the core has a Distribution Index _i,j(DI_i,j) at −

5,0 of at least about 5,750 g/m3 or a Distribution Index i,j (DI_i,j) at 10,0 of at least about 4,250 g/m3, said (DI_i,j) being determined according to Formula I;

$\begin{array}{cc}D<br><br>\text{\hspace{1em}<br><br>}<br><br>I_{\left(i,j\right)}<br><br>\left(\frac{g}{m^2}\right)=\frac{100<br><br>\left(\frac{\mathrm{cm}}{m}\right)}{N}<br><br>\underset{T=1}{\overset{N}{\sum <br><br>}}<br><br>\frac{B<br><br>\text{\hspace{1em}<br><br>}<br><br>W_T}{\left(D<br><br>\text{\hspace{1em}<br><br>}<br><br>i<br><br>\text{\hspace{1em}<br><br>}<br><br>s<br><br>\text{\hspace{1em}<br><br>}<br><br>t_T+7.62\right)}& \left(I\right)\end{array}$

 

by using the Baker Method.

19. The absorbent article of claim 18, wherein the core is comprised of about 10% to about 90% by weight of particulate or fibrous SAP.

20. The absorbent article of claim 18, wherein the core is comprised of about 20% to about 80% by weight of particulate or fibrous SAP.

21. The absorbent article of claim 18, wherein the polymer is SAP and is substantially homogeneous throughout the core.

22. The absorbent article of claim 18, wherein the core is comprised of about 40% to about 70% by weight of particulate or fibrous SAP.

23. An absorbent article comprising:

a core comprised of pulp, a polymer or a combination thereof;

wherein the core has a Distribution Index i,j (DI_i,j) at −

5,0 of at least about 5,750 g/m3;

wherein the core has a Distribution Index i,j (DI_i,j) at 0,0 of at least about 6,000 g/m3;

wherein the core has a Distribution Index i,j (DI_i,j) at 5,0 of at least about 5750 g/m3;

wherein the core has a Distribution Index i,j (DI_i,j) at 10,0 of at least about 4,250 g/m3;

wherein the core has a Distribution Index (DI) at _i,j=15,0 of at least about 3,250 g/m3, and

wherein said (DI_i,j) is determined according to Formula I;

$\begin{array}{cc}D<br><br>\text{\hspace{1em}<br><br>}<br><br>I_{\left(i,j\right)}<br><br>\left(\frac{g}{m^2}\right)=\frac{100<br><br>\left(\frac{\mathrm{cm}}{m}\right)}{N}<br><br>\underset{T=1}{\overset{N}{\sum <br><br>}}<br><br>\frac{B<br><br>\text{\hspace{1em}<br><br>}<br><br>W_T}{\left(D<br><br>\text{\hspace{1em}<br><br>}<br><br>i<br><br>\text{\hspace{1em}<br><br>}<br><br>s<br><br>\text{\hspace{1em}<br><br>}<br><br>t_T+7.62\right)}& \left(I\right)\end{array}$

 

by using the Baker Method.

24. An absorbent article comprising:

a core comprised of pulp, a polymer or a combination thereof;

said core having a first Distribution Index (DI_male) measured at a male insult point and a second Distribution Index (DI_female) measured at a female insult point, said DI_male being the DI(i,j) at the male insult point and said DI_female being the DI(i,j) at the female insult point;

wherein the difference between the DI_male and the DI_female is at most about 1,000 g/m3, and

wherein said (DI_i,j) is determined according to Formula I;

$\begin{array}{cc}D<br><br>\text{\hspace{1em}<br><br>}<br><br>I_{\left(i,j\right)}<br><br>\left(\frac{g}{m^2}\right)=\frac{100<br><br>\left(\frac{\mathrm{cm}}{m}\right)}{N}<br><br>\underset{T=1}{\overset{N}{\sum <br><br>}}<br><br>\frac{B<br><br>\text{\hspace{1em}<br><br>}<br><br>W_T}{\left(D<br><br>\text{\hspace{1em}<br><br>}<br><br>i<br><br>\text{\hspace{1em}<br><br>}<br><br>s<br><br>\text{\hspace{1em}<br><br>}<br><br>t_T+7.62\right)}& \left(I\right)\end{array}$

 

by using the Baker Method.

25. The absorbent article of claim 24, wherein the difference between the DI_male and the DI_female is at most about 900 g/m³.

26. The absorbent article of claim 24, wherein the difference between the DI_male and the DI_female is at most about 600 g/m³.

27. The absorbent article of claim 24, wherein the difference between the DI_male and the DI_female is at most about 400 g/m³.

28. The absorbent article of claim 24, wherein the DI_male and the DI_female are substantially the same.

29. The absorbent article of claim 24, wherein the DI_male is at least about 4,200 g/m³.

30. The absorbent article of claim 24, wherein the DI_female is at least about 5,500 g/m³.

31. The absorbent article of claim 24, wherein DI_max of the article corresponds to a point on the centerline about equidistant between the male insult point and the female insult point.

32. The absorbent article of claim 24, wherein the core is comprised of about 10% to about 90% by weight of particulate or fibrous SAP.

33. The absorbent article of claim 24, wherein the core is comprised of about 20% to about 80% by weight of particulate or fibrous SAP.

34. The absorbent article of claim 24, wherein the polymer is SAP and is substantially homogeneous throughout the core.

35. The absorbent article of claim 24, wherein the core is comprised of about 40% to about 70% by weight of particulate or fibrous SAP.

36. An absorbent article comprising:

a core comprised of pulp, a polymer or a combination thereof;

said core being said core being designed to provide a predetermined characteristic using general formula I;

$\begin{array}{cc}{\mathrm{DI}}_{\left(i,j\right)}<br><br>\left(\frac{g}{m^2}\right)=\frac{100<br><br>\left(\frac{\mathrm{cm}}{m}\right)}{N}<br><br>\underset{T=1}{\overset{N}{\sum <br><br>}}<br><br>\frac{{\mathrm{BW}}_T}{\left({\mathrm{Dist}}_T+7.62\right)}& \left(I\right)\end{array}$

wherein N is the total number of core cells of the core, each core cell of the core corresponding to each of a plurality of 0.75 inch squares on a predetermined grid;

wherein T is each positive integer from 1 to N, each positive integer corresponding to each core cell of the core in numerical order;

wherein DIST_T is a distance in centimeters (cm) between the center of the core cell corresponding to T and point i,j;

wherein BW_T is the basis weight of each core cell, each core cell corresponding to each value for T;

wherein i,j is a coordinate representing a point on the core; and

wherein said (DI_i,j) is determined by using the Baker Method.

37. The absorbent article of claim 36, wherein the core has a DI of at least about 6,000 g/m³.

38. The absorbent article of claim 36, wherein the core has a DI of at least about 6,500 g/m³.

39. The absorbent article of claim 36, wherein the core has a DI of at least about 7,000 g/m³.

40. The absorbent article of claim 36, wherein the predetermined characteristic is optimal absorbency, optimal cost efficiency, optimal compatibility for males and females, optimal comfort, optimal appearance or combinations thereof.

41. An absorbent article prepared by a process comprising

forming a core according to a predetermined maximum Distribution Index (DI_max), said DI_max being the maximum (DI_i,j) on the core, said (DI_i,j) being determined according to Formula I:

$\begin{array}{cc}D<br><br>\text{\hspace{1em}<br><br>}<br><br>I_{\left(i,j\right)}<br><br>\left(\frac{g}{m^2}\right)=\frac{100<br><br>\left(\frac{\mathrm{cm}}{m}\right)}{N}<br><br>\underset{T=1}{\overset{N}{\sum <br><br>}}<br><br>\frac{B<br><br>\text{\hspace{1em}<br><br>}<br><br>W_T}{\left(D<br><br>\text{\hspace{1em}<br><br>}<br><br>i<br><br>\text{\hspace{1em}<br><br>}<br><br>s<br><br>\text{\hspace{1em}<br><br>}<br><br>t_T+7.62\right)}& \left(I\right)\end{array}$

by using the Baker Method; and

placing or forming the core into an absorbent article;

wherein the core is comprised of pulp, a polymer or a combination thereof.

42. The absorbent article of claim 41, wherein the DI_max is at least about 6,500 g/m³.

43. The absorbent article of claim 41, wherein the DI_max is at least about 7,000 g/m³.

44. The absorbent article of claim 41, wherein the DI_max is at least about 7,500 g/m³.

45. The absorbent article of claim 41, wherein the core is comprised of about 10% to about 90% by weight of particulate or fibrous SAP.

46. The absorbent article of claim 41, wherein the core is comprised of about 20% to about 80% by weight of particulate or fibrous SAP.

47. The absorbent article of claim 41, wherein the core is comprised of about 40% to about 70% by weight of particulate or fibrous SAP.

48. The absorbent article of claim 41, wherein the core has a minimum Distribution Index (DI_min) of about 2,800 g/m³ to about 3,600 g/m³.

49. The absorbent article of claim 41, wherein the core has a minimum Distribution Index (DI_min) of about 2,900 g/m³ to about 3,300 g/m³.

50. The absorbent article of claim 41, wherein the core has a minimum Distribution Index (DI_min) of about 2,950 g/m³ to about 3,200 g/m³.

51. The absorbent article of claim 41, wherein the core has a Distribution Index _i,j (DI_i,j) at −

5,0 of at least about 5,750 g/m³.

52. The absorbent article of claim 41, wherein the core has a Distribution Index _i,j (DI_i,j) at 0,0 of at least about 6,000 g/m³.

53. The absorbent article of claim 41, wherein the core has a Distribution Index _i,j (DI_i,j) at 5,0 of at least about 5,750 g/m³.

54. The absorbent article of claim 41, wherein the core has a Distribution Index _i,j (DI_i,j) at 10,0 of at least about 4,250 g/m³.

55. The absorbent article of claim 41, wherein the core has a Distribution Index _i,j (DI_i,j) at 15,0 of at least about 3,250 g/m³.

56. The absorbent article of claim 41, wherein the core has a Distribution Index of at least 5,500 g/m³ at each point along a centerline of the core from 0,0 to 5,0.

57. The absorbent article of claim 41, wherein the DI_max corresponds to a a section on the core between 0,0 and 5,0.

58. An absorbent article prepared by a process comprising:

forming a core having a Distribution Index (DI) at i,j=0,0 of at least about 4750 g/m3 or a Distribution Index (DI) at i,j=12,0 of at least about 5750 g/m3, said DI i,j being determined by using the Baker Method; and

placing or forming the core into an absorbent article;

wherein the core is comprised of pulp, a polymer or a combination thereof.

59. An absorbent article prepared by a process comprising:

forming a core having a Distribution Index _i,j(DI_i,j) at −

5,0 of at least about 5,750 g/m³, a Distribution Index _i,j(DI_i,j) at 0,0 of at least about 6,000 g/m³, a Distribution Index _i,j(DI_i,j) at 5,0 of at least about 5,750 g/m³, a Distribution Index _i,j(DI_i,j) at 10,0 of at least about 4,250 g/m³; and

a Distribution Index _i,j(DI_i,j) at 15,0 of at least about 3,250 g/m³, said DI_i,j being determined by using the Baker Method;

wherein the core is comprised of pulp, a polymer or a combination thereof.

60. An absorbent article prepared by a process comprising:

forming a core comprised of pulp, a polymer or a combination thereof;

the core having a first Distribution Index (DI_male) measured at a male insult point and a second Distribution Index (DI_female) measured at a female insult point, said DI_male being the DJ(i,j) at the male insult point and said DI_female being the DI(i,j) at the female insult point;

wherein the difference between the DI_male and the DI_female is at most about 1,000 g/m³.

61. The absorbent article of claim 60, wherein the difference between the DI_male and the DI_female is at most about 900 g/m³.

62. The absorbent article of claim 60, wherein the difference between the DI_male and the DI_female is at most about 600 g/m³.

63. The absorbent article of claim 60, wherein the difference between the DI_male and the DI_female is at most about 400 g/m³.

64. The absorbent article of claim 60, wherein the DI_male and the DI_female are substantially the same.

65. The absorbent article of claim 60, wherein the DI_male is at least about 4,200 g/m³.

66. The absorbent article of claim 60, wherein the DI_female is at least about 5,500 g/m³.

67. The absorbent article of claim 60, wherein the DI_max corresponds to a point on the centerline about equidistant between the male insult point and the female insult point.

68. An absorbent article prepared by a process comprising:

selecting a Distribution Index (DI) or Distribution Index (DI) profile;

forming a core wherein the DI or DI profile is characterized by the general formula (I);

$\begin{array}{cc}{\mathrm{DI}}_{\left(i,j\right)}<br><br>\left(\frac{g}{m^2}\right)=\frac{100<br><br>\left(\frac{\mathrm{cm}}{m}\right)}{N}<br><br>\underset{T=1}{\overset{N}{\sum <br><br>}}<br><br>\frac{{\mathrm{BW}}_T}{\left({\mathrm{Dist}}_T+7.62\right)}& \left(I\right)\end{array}$

as determined by using the Baker method;

wherein N is the total number of core cells of the core, each core cell of the core corresponding to each of a plurality of 0.75 inch squares on a predetermined grid;

wherein T is each positive integer from 1 to N, each positive integer corresponding to each core cell of the core in numerical order;

wherein DIST_T is a distance in centimeters (cm) between the center of the core cell corresponding to T and point i,j;

wherein BW_T is the basis weight of each core cell, each core cell corresponding to each value for T; and

wherein i,j is a coordinate representing a point on the core.

69. An absorbent article comprising:

a core comprised of pulp, a polymer or a combination thereof;

wherein the core has a Distribution Index _i,j(DI_i,j) that is substantially the same at a first insult point and a second insult point, the first insult point being the insult point at commencement of use of the absorbent article and the second insult point being the insult point after use of the absorbent article, said DI_i,j being determined by the Baker Method.

70. The absorbent article of claim 69, wherein the core has a Distribution Index Profile tailored in accordance with the expected shift in position of the insult point over time resulting from sagging of an absorbent article during use.

71. The absorbent article of claim 69, wherein the Distribution Index_i,j (DI_i,j) is substantially the same at every point on the core along a line between the first insult point and the second insult point.

72. The absorbent article of claim 69, wherein the absorbent article is a nighttime diaper.

73. The absorbent article of claim 69, wherein the absorbent article is a travel diaper.

74. The absorbent article of claim 69, wherein the absorbent article is an extended-use diaper.

75. A method for preparing an absorbent article comprising:

selecting a Distribution Index at a point on a core or selecting a Distribution Index profile for a core by using the Baker Method

forming the core according to the selected Distribution Index or Distribution Index profile; and

placing or forming the core into the absorbent article;

wherein the core is comprised of pulp, a polymer or a combination thereof.

76. A method for determining the Distribution Index (DI) of an absorbent article comprising:

obtaining a core;

removing a plurality of samples from the core each sample corresponding to a core cell;

determining the basis weight of each core cell;

determining the distance from the center of each core cell (T) to an insult point; and

calculating the DI Index for the insult point according to general formula (I);

$\begin{array}{cc}D<br><br>\text{\hspace{1em}<br><br>}<br><br>I_{\left(i,j\right)}<br><br>\left(\frac{g}{m^2}\right)=\frac{100<br><br>\left(\frac{\mathrm{cm}}{m}\right)}{N}<br><br>\underset{T=1}{\overset{N}{\sum <br><br>}}<br><br>\frac{B<br><br>\text{\hspace{1em}<br><br>}<br><br>W_T}{\left(D<br><br>\text{\hspace{1em}<br><br>}<br><br>i<br><br>\text{\hspace{1em}<br><br>}<br><br>s<br><br>\text{\hspace{1em}<br><br>}<br><br>t_T+7.62\right)}& \left(I\right)\end{array}$

by using the Baker method;

wherein N is the total number of core cells of the core, each core cell of the core corresponding to each of a plurality of 0.75 inch squares on a predetermined grid;

wherein T is each positive integer from 1 to N, each positive integer corresponding to each core cell of the core in numerical order;

wherein DIST_T is a distance in centimeters (cm) between the center of the core cell corresponding to T and point i,j;

wherein BW_T is the basis weight of each core cell, each said core cell corresponding to each value for T; and

wherein i,j is a coordinate representing a point on the core.