Note: Descriptions are shown in the official language in which they were submitted.
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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 Figures 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 a 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 provides a good fitting to the wearer's crotch
because the diaper is formed in the crotch zone with the
cutout so as to assure that the leg-openings are located below
the bottom surface of the crotch zone, a central area of the
crotch zone 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.
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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.
To achieve the object set forth above, the invention
resides in disposable absorbent pants comprising front and
rear bodies each consisting of a liquid-permeable topsheet, a
liquid-impermeable backsheet and liquid-absorbent panels
sandwiched therebetween and assembled to form pants having a
waist-opening as well as leg-openings, and circumferentially
stretchable elastic members attached around the respective
-~-oepn ~ characterized in that said front and rear bodies are
separately formed, each of said panels being dimensioned so
that said top- and backsheets have their outer peripheral
edges extending outward beyond outer peripheral edges of the
respective panels, the respective outer peripheral edges of
said top- and backsheets being bonded together along the outer
peripheral edges thereof, and the respective bodies are bonded
together along the middle of their lower edges to define a
crotch zone as well as along laterally opposite side edges,
thus forming a basic structure of the pants; and an auxiliary
liquid-absorbent panel curved in a U-shape is bonded at least
at top ends of this U-shape to an inner surface of said basic
structure in the crotch zone.
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Preferably, said crotch zone defined by said
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
with reference to the accompanying drawings, in which:
Figure 1 is a perspective view showing an embodiment
of a diaper constructed according to the teachings of the
invention; and
Figure 2 is a sectional view taken along a line X-X
in Figure 1.
Description of the Preferred Embodiments
Referring to Figures 1 and 2, a diaper's basic
structure 1 generally comprises front and rear bodies 2, 3
assembled in the form Gf 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 liquid-impermeable
backsheet 7 and a liquid-absorbent panel 8 sandwiched between
said top- and backsheets 6, 7.
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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 by heat or
supersonic means along 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 of the front and rear bodies 2, 3 and at least
inner sides of respective leg-openings 5 extend downward
beyond an apex 16 of the convexly curved welding line llb.
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 bodies
are illustrated as extending neither parallel with nor
perpendicularly to a vertical axis 14. These side edges may
however extend parallel with the vertical axis 14 and these
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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 liquid-
absorbent panel 15 which is elongate longitudinally of the
diaper's basic structure 1. The auxiliary panel 15 comprises
a liquid-absorbent core 15a covered with liquid-permeable
sheets 15b and is bonded at least at longitudinally opposite
ends to the top surface of the topsheet 6 with means of
adhesive so as to be curved in a U-shape. With the diaper's
basic structure 1 being put on a wearer, the auxiliary panel
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 15 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. However, it is also possible within
the scope of the invention to arrange the auxiliary panel 15
so that the bottom of the auxiliary panel 15 may remain in
contact with the top surface of the diaper's crotch zone even
in th~ curved state. 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.
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Components of the diaper 1 may be made from materials
commonly used in well known diapers. 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 15b 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
liquid-absorbent panel over the crGtch zone allows the crotch
zone to absorb liquid excretion sufficiently to prevent any
liquid excretion from leaking along the laterally opposite side
edges of the crotch zone.
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