Patent US4634440A successfully refreshed from Google Patents.
US4634440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Absorbent article
Assignee: Essity Hygiene and Health AB
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Filing: 1985-05-14
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Granted: 1987-01-06
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Expires: 2005-05-14
Abstract
Abstract An absorbent article, such as a diaper, a sanitary towel or bandage, having an absorbent core, a liquid-permeable topsheet intended to be in contact with the wearer when the article is worn, and a liquid-impermeable layer arranged on the opposite side of the absorbent core. The liquid-permeable topsheet comprises a perforated but otherwise liquid-impermeable layer, the perforations comprising straight ducts which are of uniform width along the whole of their lengths. The ends of these ducts freely project away from the topsheet and extend into the absorbent core. Fibers extend into the ducts in a manner such that the fiber density in the ducts decreases in a direction away from the free ends of the ducts, so that the fibers form capillaries which taper toward the interior of the absorbent article.
Inventors
- 👤 Leif U. R. Widlund
- 👤 Sven G. Bergdahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:25
CPC Classifications
A; A61; A61F; A61F13/00; A61F13/15; A61F13/51; A61F13/511; A61F13/512; A61F13/45; A61F13/47; A61F13/49; A61F13/513; A61F13/51305
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
133 words
An absorbent article, such as a diaper, a sanitary towel or bandage, having an absorbent core, a liquid-permeable topsheet intended to be in contact with the wearer when the article is worn, and a liquid-impermeable layer arranged on the opposite side of the absorbent core, the liquid-permeable topsheet comprising a perforated but otherwise liquid-impermeable layer; the perforations comprising straight ducts which are of a uniform width along the whole of their lengths, the ends of said ducts freely projecting away from the topsheet and extending into the absorbent core, and fibers extending into the ducts in a manner such that the fiber density in said ducts decreases in a direction away from the free ends of said ducts, such that said fibers form capillaries which taper toward the interior of the absorbent article.
Claim 2
Dependent Claim
133 words
An absorbent article, such as a diaper, a sanitary towel or bandage, having an absorbent core, a liquid-permeable topsheet intended to be in contact with the wearer when the article is worn, and a liquid-impermeable layer arranged on the opposite side of the absorbent core, the liquid-permeable topsheet comprising a perforated but otherwise liquid-impermeable layer; the perforations comprising straight ducts which are of a uniform width along the whole of their lengths, the ends of said ducts freely projecting away from the topsheet and extending into the absorbent core, and fibers extending into the ducts in a manner such that the fiber density in said ducts decreases in a direction away from the free ends of said ducts, such that said fibers form capillaries which taper toward the interior of the absorbent article.
Claim 3
Dependent Claim
30 words
An article according to claim 1, in which the fibers extending into the ducts comprise fibers located in a thin fiber layer airlaid on the undersurface of the perforated topsheet.
Claim 4
Dependent Claim
30 words
An article according to claim 2, in which the thin fiber layer is bonded to the undersurface of the perforated topsheet and in the ducts by means of a binder.
Claim 5
Dependent Claim
29 words
An article according to claim 1, in which the cross-sectional size of the ducts is between 0.1 and 6 mm and the length thereof between 0.2 and 10 mm.
Claim 6
Dependent Claim
30 words
An article according to claim 1 in which the walls defining said ducts are of undulating configuration, with their crests and valleys extending in the longitudinal direction of the ducts.
Claim 7
Dependent Claim
22 words
An article according to claim 1, in which together the perforations constitute between 10 and 70% of the area of the topsheet.
References Cited (Backward Citations)
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Cited
US3929135A
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US4041951A
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Cited
US4341217A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-01-05 | 1990-07-07 | 1991-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-05 | 1994-07-07 | 1995-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-05 | 1998-07-07 | 1999-01-06 | $7700.00 | Window Closed / Lapsed |