Absorbent article

• US 7,696,402 B2
• Filed: 06/30/2006
• Issued: 04/13/2010
• Est. Priority Date: 07/01/2005
• Status: Active Grant

• Current Assignee: Unicharm Corporation
• Original Assignee: Unicharm Corporation
• Inventors: Kudo, Jun, Nishikawa, Kumiko, Miyama, Takuya, Habu, Chiemi
• Primary Examiner(s): Zalukaeva; Tatyana
• Assistant Examiner(s): Anderson; Lynne
• Application Number:
  US11/427,803
• Publication Number:
  US 20070005036A1
• Time in Patent Office: 1,383 Days
• Field of Search: 604/379, 604/380, 604/385.101
• US Class Current: 604/380
• CPC Class Codes: A61F 13/4704 having preferential bending zones, e.g. fold lines or grooves
• CPC Class Codes: A61F 13/4758 the means preventing fluid flow in a longitudinal direction

Abstract

An absorbent article includes a compressed groove provided on a body-side surface of a sanitary napkin includes a pair of lateral groove segments extending substantially in the longitudinal direction symmetrically about a longitudinal center line and a pair of rear groove segments converging rearward from respective rear ends of the pair of lateral groove segments so that the compressed groove as a whole presents an elongated shape which is angular rearward. The rear side groove segment has a curve conforming, in the vicinity of its rear end, with an arc of a circle having a predetermined radius and inscribed to the rear side groove segment. A bottom covering region extending rearward from the rear end of the rear groove segment has a predetermined thickness and is adapted to be folded along the longitudinal center line so that the bottom covering region can become convex on the side of the body-side surface. A distance between a pair of proximal ends of the rear side groove segment as measured in the transverse direction is in a predetermined range and a distance from the pair of proximal ends to the rear end of the rear groove segment as measured in the longitudinal direction is in a predetermined range.

Claims

1. An absorbent article having a longitudinal direction, a transverse direction, a body-side surface, a clothes-side surface, longitudinally opposed front and rear ends and transversely opposite side edges, said article comprising:

a liquid-absorbent layer, and

a continuous groove compressed into the body-side surface of the liquid-absorbent layer, wherein;

said compressed groove comprises;

a pair of lateral groove segments extending substantially in said longitudinal direction and arranged symmetrically with respect to a longitudinal center line of said article,

a front groove segment extending forward from respective front ends of said lateral groove segments so as to connect said front ends of said lateral groove segments together, said front groove segment defining a front side curve which is convex toward the front end of the article and which is symmetrical with respect to the longitudinal center line of said article, and

a rear groove segment extending rearward from respective rear ends of said lateral groove segments so as to connect said rear ends of said lateral groove segments together, said rear groove segment defining a rear side curve which is convex toward the rear end of the article and which is symmetrical with respect to the longitudinal center line of said article, wherein said compressed groove as a whole presents an elongated, continuous and closed loop which is longer in the longitudinal direction than it is wide in the transverse direction;

said rear side curve has, in the vicinity of its rear end located on the longitudinal center line, a radius in a range of 0 to 10 mm;

said front side curve has, in the vicinity of its front end located on the longitudinal center line, a radius greater than the radius of the rear side curve; and

said absorbent layer comprises a bottom covering region which extends rearward from the rear end of said rear groove segment, has a thickness in a range of 1 to 5 mm, and is adapted to be folded along the longitudinal center line so that said bottom covering region can become convex, in use, toward a wearer;

wherein a thickness of the absorbent layer within the closed-loop shape defined by the compressed groove decreases gradually in the longitudinal direction from a front portion in the vicinity of the front end of the front groove segment to a rear portion in the vicinity of the rear end of the rear groove segment.

2. The article defined by claim 1, wherein said bottom covering region has a flexural stiffness in a range of 100 to 400 mg as measured in said transverse direction.

3. The article defined by claim 1, wherein the distance from the rear end of said rear groove segment to the rear end of said liquid-absorbent layer as measured in said longitudinal direction is 50 mm or longer.

4. The article as defined by claim 1, wherein the lateral groove segments are convex inwardly toward the longitudinal center line.

5. The article as defined by claim 1, wherein said continuous, compressed groove further comprises:

an outer front groove segment located forward of the front groove segment and extending forward from the respective front ends of said lateral groove segments so as to connect said front ends of said lateral groove segments together, said outer front groove segment defining an outer front side curve which is convex toward the front end of the article and which is symmetrical with respect to the longitudinal center line of said article, and

an outer rear groove segment located rearward of the rear groove segment and extending rearward from the respective rear ends of said lateral groove segments so as to connect said rear ends of said lateral groove segments together, said outer rear groove segment defining an outer rear side curve which is convex toward the rear end of the article and which is symmetrical with respect to the longitudinal center line of said article,

wherein

said outer front and rear groove segments and said lateral groove segments together define an elongated, continuous and closed outer loop which is longer the in longitudinal direction that it is wide in the transverse direction; and

said front and rear groove segments and said lateral groove segments together define said elongated, continuous and closed loop which is an inner loop.

6. The article as defined by claim 5, wherein

the longitudinal center line intersects an imaginary line, which extends in the transverse direction and defines the minimum distance between the lateral groove segments, at an intersection that is adapted to be a target for a position of a wearer'"'"'s vaginal orifice in use;

and

each of said inner and outer loops is asymmetrical with respect to said imaginary line, with the front side curve or the outer front side curve being closer, in the longitudinal direction, to the imaginary line than the rear side curve or the outer rear side curve, respectively;

a distance, as measured in said transverse direction, between said rear ends of said lateral groove segments, from which the rear side curve and the outer rear side curve branch, is in a range of 25 to 55 mm;

a distance, as measured in said longitudinal direction, from said rear ends of said lateral groove segments to the rear end of the rear groove segment is in a range of 30 to 150 mm; and

a distance, as measured in said longitudinal direction, from the rear end of the rear groove segment to the rear end of the outer rear groove segment is 40 mm or longer.

7. The article defined by claim 6, wherein a distance, as measured in said longitudinal direction, from the rear end of the rear groove segment to the rear end of the absorbent layer is 50 mm or longer.

8. The article defined by claim 7, wherein the distance from the rear ends of said lateral groove segments to the imaginary line as measured in said longitudinal direction is in a range of 0 to 80 mm.

9. The article defined by claim 1, wherein a bottom of the compressed groove is free of absorbent material.

10. An absorbent article having a longitudinal direction, a transverse direction, a body-side surface, a clothes-side surface, longitudinally opposed front and rear ends and transversely opposite side edges, said article comprising:

a liquid-absorbent layer, and

a continuous groove compressed into the body-side surface of the liquid-absorbent layer, wherein;

said compressed groove comprises;

a pair of lateral groove segments extending substantially in said longitudinal direction and arranged symmetrically with respect to a longitudinal center line of said article,

a front groove segment extending forward from respective front ends of said lateral groove segments so as to connect said front ends of said lateral groove segments together, said front groove segment defining a front side curve which is convex toward the front end of the article and which is symmetrical with respect to the longitudinal center line of said article, and

a rear groove segment extending rearward from respective rear ends of said lateral groove segments so as to connect said rear ends of said lateral groove segments together, said rear groove segment defining a rear side curve which is convex toward the rear end of the article and which is symmetrical with respect to the longitudinal center line of said article, wherein said compressed groove as a whole presents an elongated, continuous and closed loop which is longer in the longitudinal direction than it is wide in the transverse direction;

the longitudinal center line intersects an imaginary line, which extends in the transverse direction and defines the minimum distance between the lateral groove segments, at an intersection that is adapted to be a target for a position of a wearer'"'"'s vaginal orifice in use; and

said compressed groove is asymmetrical with respect to said imaginary line, with the front side curve being closer, in the longitudinal direction, to the imaginary line than the rear side curve;

a distance between said rear ends of said lateral groove segments as measured in said transverse direction is in a range of 25 to 55 mm;

a distance from said rear ends of said lateral groove segments to the rear end of the rear groove segment as measured in said longitudinal direction is in a range of 30 to 150 mm; and

said absorbent layer comprises a bottom covering region which extends rearward from the rear end of said rear groove segment, has a thickness in a range of 1 to 5 mm, and is adapted to be folded along the longitudinal center line so that said bottom covering region can become convex, in use, toward a wearer;

wherein a thickness of a majority of the absorbent layer within the closed-loop shape defined by the compressed groove decreases gradually in the longitudinal direction from the front groove segment to the rear groove segment.

11. The article as defined by claim 10, wherein

said rear side curve has, in the vicinity of its rear end located on the longitudinal center line, a radius in a range of 0 to 10 mm;

and

said front side curve has, in the vicinity of its front end located on the longitudinal center line, a radius greater than the radius of the rear side curve.

12. The article defined by claim 11, wherein the distance from the rear end of said rear groove segment to the rear end of said liquid-absorbent layer as measured in said longitudinal direction is 50 mm or longer.

13. The article defined by claim 10, wherein the distance from the rear ends of said lateral groove segments to the imaginary line as measured in said longitudinal direction is in a range of 0 to 80 mm.

14. The article defined by claim 10, wherein a bottom of the compressed groove is free of absorbent material.

15. An absorbent article having a longitudinal direction, a transverse direction, a body-side surface, a clothes-side surface, longitudinally opposed front and rear ends and transversely opposite side edges, said article comprising:

a liquid-absorbent layer, and

a continuous groove compressed into the body-side surface of the liquid-absorbent layer, wherein;

said compressed groove comprises;

a pair of lateral groove segments extending substantially in said longitudinal direction and arranged symmetrically with respect to a longitudinal center line of said article,

a front groove segment extending forward from respective front ends of said lateral groove segments so as to connect said front ends of said lateral groove segments together, said front groove segment defining a front side curve which is convex toward the front end of the article and which is symmetrical with respect to the longitudinal center line of said article, and

a rear groove segment extending rearward from respective rear ends of said lateral groove segments so as to connect said rear ends of said lateral groove segments together, said rear groove segment defining a rear side curve which is convex toward the rear end of the article and which is symmetrical with respect to the longitudinal center line of said article, wherein said compressed groove as a whole presents an elongated, continuous and closed loop which is longer in the longitudinal direction than it is wide in the transverse direction;

a thickness of the absorbent layer within the closed-loop shape defined by the compressed groove decreases gradually in the longitudinal direction from the front groove segment to the rear groove segment; and

wherein the lateral groove segments are convex inwardly toward the longitudinal center line.

16. The article defined by claim 15, wherein a bottom of the compressed groove is free of absorbent material.

17. The article defined by claim 15, wherein the thickness of the absorbent layer within the closed-loop shape and on the longitudinal center line is highest at a first point located in the vicinity of and forward of said front ends of the lateral groove segments, and

the thickness of the absorbent layer decreases gradually along the longitudinal center line to a second point located in the vicinity of and rearward of said rear ends of the lateral groove segments.

18. The article defined by claim 17, wherein a bottom of the compressed groove is free of absorbent material.