AU668970B2

AU668970B2 - Disposable absorbent pants

Info

Publication number: AU668970B2
Application number: AU44657/93A
Authority: AU
Inventors: Yoshihisa Fujioka; Hirotomo Mukai
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 1992-08-24
Filing date: 1993-08-13
Publication date: 1996-05-23
Anticipated expiration: 2013-08-13
Also published as: CN2164815Y; DE59308429D1; KR940005091U; GB2269998B; JPH0621621U; EP0585766B1; CA2104504A1; EP0585766A1; JP2580182Y2; GB2269998A8; AU4465793A; GB9317594D0; KR200150696Y1; CA2104504C; ES2117076T3; GB2269998A

Description

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AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Application Number: Lodged: Int. Class Complet. Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Uni-Charm Corporation Actual Inventor(s): Hirotomo Mukai Yoshihisa Fujioka Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: DISPOSABLE ABSORBENT PANTS Our Ref 337620 POF Code: 1647/76530 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): r DISPOSABLE ABSORBENT PANTS BACKGROUND OF THE INVENTION The present invention relates to absorbent pants such as disposable diapers.

Pants type disposable diaper is well known, for example, from Japanese Patent Gazette No. 1992-42017.

Referring to Figs. 10 and 11 of this patent gazette, this diaper of prior art comprises a laminate consisting of a liquid-permeable topsheet cut to be longer sideways, a liquid-impermeable backsheet also cut to be longer sideways and a liquid-absorbent panel sandwiched therebetween, and an elastic member extending along one of longitudinally opposite edges of the laminate around a waist opening as well as elastic members extending along the other edge around respective leg-openings, wherein said laminate is transversely folded in two, edges of the laminate thus folded opposite to the fold are bonded together and edges of cutouts formed at middle position of the laminate's lower end are also bonded together so as to define a crotch zone.

While the diaper disclosed in the above-identified patent gazette presents good fitness to the wearer's crotch because the diaper is formed in the crotch zone with \im cutout so as to assure that the leg-openings -bo\ located DIS.OS*BLE ORBENT A BACKGROU -f -F i V !The 4 to w pa, a i d ia Pat typ i psal dipe i- wel known loeren ae lo onedtoehe s a t efnea roc below the bottom surface of the crotch zone, a central area of the crotch zone -a a2 a 1 J~ a a a,.

contains no liquid-absorbent panel and therefore it is difficult to prevent liquid excretion from leaking out along laterally opposite side edges of the crotch zone.

SUMMARY OF THE INVENTION Accordingly, it is a principal object of the invention to provide an improved pants type diaper comprising front and rear bodies separately formed and bonded together so that a liquid-absorbent panel covers also a bonding line in the crotch zone of the front and rear bodies.

According to the present invention there is provided disposable absorbent pants including a front body, a rear body and an auxiliary liquid-absorbent panel disposed between said front body and said rear body, said pants having a waist-opening, two leg-openings and a crotch area extending between said leg-openings; each said body including a liquid-permeable topsheet, a liquid-impermeable backsheet and a liquid-absorbent panel sandwiched therebetween: each body having spaced apart side edges that are bonded together to form spaced apart side edges of said pants that extend between each leg-opening and said waist-opening; each body having bottom edges, portions of the bottom edges of said bodies being spaced apart from each other to form leg-openings and the remaining portions of the bottom edges of said bodies being bonded together along a convexly curved welding line to thereby form a convexly curved crotch zone that extends between said leg-openings, said convexly curved crotch zone having an apex that is closer to said waist-opening than are said leg-openings; said auxiliary liqud-absorbent panel having a generally U-shaped configuration that is positioned in said crotch zone and bonded to the interior 25 surface of said pants, the open end of said U-shaped configuration facing toward said waist-opening, the closed end of said U-shaped configuration being mounted so as to float at a spaced distance of at least 10 mm away from said convexly curved welding line of said convexly curved crotch zone.

AMB:P44657.DOC -2backsheets being bonded together along the outer periphe edges thereof, and the respective bodies ac/e bonded together along the middle of their lower tges to define a crotch zone as well as along la ally oppositc side edges, thus forming a basics ructure of the pants; and an auxiliary liqu *absorbent panel curved in a U-shape is bonded least at top ends of this U-shape to an inner surface of said basic structure in the crotch zone.

Preferably, ajd \crotch zone defined by maid convexly curved welding line is formed along its outer edges with a correspondingly curved cutout.

With the pants constructed according to the invention as outlined above, the crotch zone is reliably centered to the wearer's crotch and laterally opposite sides of the crotch zone cover at least inner sides of the wearer's thighs, respectively. The crotch zone also contains the liquid-absorbent panel and therefore liquid excretion is effectively absorbed also in this zone.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described by way of example in reference with the accompanying drawings, in which: Fig. 1 is a perspective view showing an embodiment of a diaper constructed according to the teachings of the invention; and -3- -~II Fig. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Fig. 1 and 2, a diaper's basic structure 1 generally comprises front and rear bodies 2, 3 assembled in the form of pants having a waist-opening 4 and a pair of leg-openings 5. Each of front and rear bodies 2, 3 comprises a liquid-permeable topsheet 6, a liquidimpermeable backsheet 7 and a liquid-absorbent panel 8 sandwiched between said top- and backsheets 6, 7.

Lower ends of front and rear bodies 2, 3 are formed at middle positions with cutouts 9 defining a crotch zone.

The front and rear bodies 2, 3 are welded together along heat or supersonic welding lines lla, llb extending parallel with the cutouts 9 and the laterally opposite side edges 10, respectively, so as to leave narrow edges of these cutouts 9 and opposite side edges not welded. A size, shape and curvature radius of the welding line llb may be appropriately selected depending on whether the diaper is for adult or for baby so far as the welding line llb is convexly curved toward waist lines ofront and rear bodies 2, 3 and at least inner sides of respective leg-openings extend downward beyond an apex 16 of the convexly curved welding line llb.

:ih ,4 Circumferentially stretchable elastic members 12, 13 are interposed between respective edges of top- and backsheets 6, 7 extending beyond the panel 8 around a waist-opening and leg-openings, respectively, and said edges are closed together by hot melt type adhesive or said welding means. Laterally opposite side edges of top- and backsheets 6, 7 extending beyond the panel 8 are also closed together in the similar manner.

The laterally opposite side edges and the lower edges around the respective leg-openings of the front and rear 1odies are illustrated as extending neither parallel with nor perpendicu] rly to a vertical axis 14, these side edges may extend parallel with the vertical axis 14 and these lower edges around the respective leg-openings may extend perpendicularly to said vertical axis 14 within the scope of the invention.

The diaper's basic structure 1 is provided on the top surface of its crotch zone with an auxiliary liquidabsorbent panel 15 which is elongate longitudinally of the diaper's basic structure 1. The auxiliary panel comprises a liquid-absorbent core 15a covered with liquidpermeable sheets 15b and is bonded at least at longitudinally opposite ends to the top surface of the topsheet 4 with means of adhesive so as to be curved in a 11* *1-7V \=n U-shape. With the diaper's basic structure 1 being put n2 !e I a wearer, the auxiliary panel 15 is curved in a U-shape together with the diaper's basic structure 1. The auxiliary panel 15 is preferably bonded to the diaper's basic structure 1 in a manner such that the auxiliary panel thus curved floats above the top surface of the basic structure's crotch zone and more specifically the curved auxiliary panel 15 has its outer bottom spaced by a distance S of at least 10 mm from the top surface of the basic structure's crotch zone. H i i als.

auxiliary panel 15 so thaJ-t. o m of the auxiliary S n my remain in contact with the top surface of the i g a th V The auxiliary panel 15 may have its bottom layer comprising a liquid-impermeable sheet and/or have stretchable side flaps extending from laterally opposite sides thereof without departure from the scope of the invention.

Components of the diaper 1 may be made from materials commonly used in the well known diaper. For example, the topsheet 6 may be made of nonwoven fabric, the backsheet 7 may be made of plastic film, the panel 8 may be made of fluff pulp mixed with superabsorbent polymer, the elastic members 12, 13 may be made of natural or synthetic rubber.

The core 15a of the panel 15 may be made of fluff pulp mixed with superabsorbent polymer and the sheet -6j ilb"al~: I Z a ir r :I I;A- 0( ;'r -rr 'Ii i.

i 1., :I L ~i- 73 4r ,41 P~ :'ti covering the core 15a may be made of nonwoven fabric, preferably stretchable nonwoven fabric.

With the diaper constructed according to the invention as described above, provision of the auxiliary liquidabsorbent panel over the crotch zone allowsthe crotch zone to absorb liquid excretion sufficiently to prevent any liquid excretion from leaking along the laterally opposite side edges of the crotch zone.

Claims

1. Disposable absorbent pants including a front body, a rear body and an auxiliary liquid-absorbent panel disposed between said frcnt body and said rear body, said pants having a waist-opening, two leg-openings and a crotch area extending between said leg-openings, each said body including a liquid-permeable topsheet, a liquid-impermeable backsheet and a liquid-absorbent panel sandwiched therebetween, each body having spaced apart side edges that are bonded together to form spaced apart side edges of said pants that extend between each leg-opening and said waist-opening, each body having bottom edges, portions of the bottom edges of said bodies being spaced apart from each other to form leg-openings and the remaining portions of the bottom edges of said bodies being bonded together along a convexly curved welding line to thereby form a convexly curved crotch zone that extends between said leg-openings, said convexly curved crotch zone having an apex that is closer to said waist-opening than are said leg-openings, said auxiliary liquid-absorbent panel having a generally U-shaped configuration, that is positioned in said crotch zone and bonded to the interior surface of said pants, the open end of said U-shaped configuration facing toward said waist-opening, the closed end of said U-shaped configuration being mounted so as to float at a spaced distance of at least 10 mm away from said convexly curved welding line of said convexly curved crotch zone.

2. Disposable absorbent pants substantially as herein described with reference to the accompanying drawings. 25 25 elk DATED: 27 MARCH 1996 PHILLIPS ORMONDE FITZPATRICK Attorneys for: UNI-CHARM CORPORATION AMB.P44657.DOC A B S T R A C T Disposable absorbent pants improved so that liquid excretion can be effectively prevented from leaking out along laterally opposite side edges of crotch zone. Front and rear bodies 2, 3 are placed one unon another and welded together along laterally cpposite side edges as well as along the middle of crotch zone to form a basic structure 1 of pants and there is provided an auxiliary liquid-absorbent panel 15 over the top surface of the crotch zone.