Sanitary napkin

• US 6,575,948 B1
• Filed: 07/14/1999
• Issued: 06/10/2003
• Est. Priority Date: 07/15/1998
• Status: Expired due to Fees

• Current Assignee: Unicharm Corporation
• Original Assignee: Unicharm Corporation
• Inventors: Kashiwagi, Masahiro, Jibiki, Keiichi
• Primary Examiner(s): Lo, Weilun
• Assistant Examiner(s): ANDERSON, CATHARINE L
• Application Number:
  US09/352,057
• Time in Patent Office: 1,427 Days
• Field of Search: 604/385.17, 604/385.04, 604/385.01, 604/378-380, 604/385.101
• US Class Current: 604/385.101
• CPC Class Codes: A61F 13/4702 having a reinforcing member
• CPC Class Codes: A61F 13/47218 with a raised crotch region, e.g. hump
• CPC Class Codes: A61F 13/47263 with activating means, e.g. elastic, heat or chemical activatable means
• CPC Class Codes: A61F 13/514 Backsheet, i.e. the impermeable cover or layer furthest from the skin A61F13/15211, A61F13/15252 take precedence

Abstract

A sanitary napkin has an absorbent core convexly curved upward and the absorbent core is provided on its lower side with a pad adapted to hold a curved shape of the absorbent core. The pad is formed on its upper side with a plurality of projections and continuous troughs so that the projections are bonded to the lower side of the absorbent core and the troughs form a continuous tunnel between the absorbent core and the pad. The pad thus formed improves a breathability of the sanitary napkin during its use.

Claims

1. A sanitary napkin having a longitudinal direction and a transverse direction, said sanitary napkin comprising:

a liquid-pervious topsheet;

a liquid-impervious backsheet;

a liquid-absorbent core disposed between the liquid-pervious topsheet and the liquid-impervious backsheet, said liquid-absorbent core having a transverse cross-section which is curved toward said liquid-pervious topsheet; and

a pad positioned against a lower surface of said liquid-absorbent core in a curved zone thereof,

said pad being convexly curved toward said liquid-pervious topsheet and in substantial conformity with the liquid-absorbent core,

a surface of said pad which is placed against said liquid-absorbent core comprises a plurality of discrete projections and continuous troughs that include a plurality of trough sections each defined between adjacent ones of said plurality of projections so that the trough sections extend longitudinally as well as transversely of said liquid-absorbent core to intersect one another, and opposite ends of each trough section terminating at a peripheral edge of said pad,

said pad being placed against said lower surface of said liquid-absorbent core at tops of said plurality of projections so that a plurality of tunnel sections each having opposite ends opened at said peripheral edge of said pad are formed between said continuous troughs and said lower surface of said liquid-absorbent core.

2. A sanitary napkin according to claim 1, wherein said pad lies in a transversely middle zone of said sanitary napkin so that imaginary reference lines which extend parallel to a center line dividing a width of said sanitary napkin in two are alternately interrupted by said plurality of projections and troughs of said pad.

3. A sanitary napkin according to claim 1, wherein said pad is made of thermoplastic synthetic fibers.

4. A sanitary napkin according to claim 1, wherein said pad is made of crimped thermoplastic conjugated fibers.

5. A sanitary napkin according to claim 1, wherein said pad is made of thermoplastic hollow fibers.

6. A sanitary napkin according to claim 1, wherein a height of each of said plurality of projections as measured from a bottom of said troughs to a top of each of said plurality of projections is about 0.3 to about 3 mm.

7. A sanitary napkin according to claim 1, wherein said troughs rectilinearly extend obliquely across said longitudinal direction of said liquid-absorbent core.

8. A sanitary napkin according to claim 1, wherein said troughs meander so as to obliquely intersect said longitudinal direction of said liquid-absorbent core.

9. A sanitary napkin according to claim 1, wherein said pad is thicker at said projections than at said troughs.

10. A sanitary napkin according to claim 1, wherein said pad is made of thermoplastic synthetic fibers, having a lower density at said projections than at said troughs.

11. A sanitary napkin according to claim 1, wherein said pad, in its transversely curved state, has a rigidity which gradually decreases from its transversely middle zone to its transversely opposite side edges.

12. A sanitary napkin according to claim 1, wherein said pad is made of a foamed plastic sheet.

13. A sanitary napkin according to claim 1, wherein said pad is made of a compressed foam plastic sheet.

14. A sanitary napkin according to claim 1, wherein the plurality of discrete projections are arranged in a two-dimensional array.