Note: Descriptions are shown in the official language in which they were submitted.
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DISPOSABLE GARMENTS
BACKGROUND OF THE INVENTION
The present invention relates to disposable garments
and, more particularly, to disposable garments such as
open-type diaper, diaper in the form of underpants or
briefs (inclusive of diaper for incontinence) or so-
called infant training underpants.
It is well known to provide such garments, for
example, in the form of underpants or briefs,
particularly said infant training underpants with
suitable elastic members around the respective leg-
openings as well as around a waist-opening and with an
absorbent core sandwiched between water-permeable
topsheet and backsheet.
Conventionally in such garments, both the topsheet
and backsheet have not been elastic at all or, even if
they are somewhat elastic, the elasticity has not been
sufficient for the garments to be reliably put on the
wearer's body with good fit.
In view of a fact that the topsheet and backsheet
preferably should be air-permeable, these sheets have
usually been made of nonwoven fabric and, as a
consequence, it has been inevitable that a quantity of
liquid excretion once absorbed by the absorbent core
partially leaks even if the core is interposed between
the sheets. Particularly in the case of infant training
underpants, more or less leakage of liquid excretions
might be tolerated because of the particular purpose of
such underpants and for this reason the problem of
leakage has often intentionally been left as it is.
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However, it is undesirable that a lot of liquid
excretions leak immediately after occurrence of the
wearer's excretions although no perfect prevention of
such leakage might be required in this particular case.
A primary object of the invention is to deal with an
antinomic relationship between the fact that it is
preferred to use the topsheet and backsheet having good
air-permeability, as it has conventionally been for
disposable garments, and the fact that it is undesirable
to use nonwoven fabric at least for the backsheet in
order to minimize possible leakage of liquid excretions.
SUMMARY OF THE INVENTION
The object set forth above is achieved, according to
the invention, by utilizing elastic nonwoven fabric for
the topsheet and backsheet, interposing elastomer film as
an elastic barrier sheet between the top- and backsheets
and intermittently bonding the barrier sheet to at least
one of the topsheet and backsheet.
When the barrier sheet is interposed between the
topsheet and backsheet substantially over the entire area
thereof, it is preferred to provide the barrier sheet
along both sides in front and rear zones with
perforations serving as air vents.
With the garments constructed according to the
invention as has been mentioned above, the topsheet and
backsheet as well as the barrier sheet integrally stretch
and contract as the wearer's body moves. The barrier
sheet apparently serves as the barrier blocking a
quantity of body fluids against leaking toward the outer
surface of the garments.
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If the barrier sheet is provided along both sides in
front and rear zones with perforations serving as air
vents, the air vents will assure desired ventilation even
in the case that the barrier sheet is interposed between
the topsheet and backsheet substantially over the entire
area thereof. If the barrier sheet is interposed between
the topsheet and backsheet over an area being narrower
than the area of the topsheet and backsheet but larger
than the core, desired ventilation will be assured
through the both side areas of the topsheet and backsheet
not occupied by the barrier sheet.
If the core is sandwiched between the topsheet and
backsheet, the quantity of body fluids that permeate
through the topsheet is absorbed by the core.
Therefore, in accordance with the present invention,
there is provided a disposable liquid absorbing garment
comprising in combination
(a) a liquid absorbent core having a topside and a
bottom side, and a perimeter,
(b) an elastic water-permeable non-woven topsheet
having spaced apart side edges, said topsheet being
positioned against the topside of said liquid
absorbent core and extending outwardly beyond the
perimeter of said absorbent core,
(c) an elastic barrier sheet that is coextensive in
area with said topsheet and positioned against the
bottom side of said absorbent core, said barrier
sheet having two spaced apart side portions which
extend laterally outwardly with respect to the
perimeter of said absorbent core,
(d) an elastic water-permeable nonwoven backsheet
having spaced apart side edges, said backsheet being
bonded to said topsheet and positioned against a
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surface of the elastic barrier sheet that is away
from said absorbent core,
(e) means for bonding said elastic barrier sheet to
said backsheet over the entire elastic barrier sheet
so that the elastic backsheet and the elastic
barrier sheet integrally stretch and contract
together as a wearer's body moves,
(f) said elastic barrier sheet being substantially
coextensive in area with said backsheet, and
(g) leg elastic members and waist elastic members
disposed between said topsheet and said backsheet,
the combination of said topsheet and backsheet being
folded along a longitudinally middle portion and
being bonded together along portions of their side
edges so as to form two spaced apart leg openings on
opposite sides of a folded combination resulting in
a single waist opening, and a crotch area,
wherein said leg elastic members comprise
(1) a first elastic submember that extends
from one side of said folded combination
to another side of said folded combination
(2) a second elastic submember that
extends from one side of said folded
combination to another side of said folded
combination,
(3) said first and second elastic
submembers intersecting each other at
spaced apart points in said crotch area of
said folded combination,
(4) portions of said first and second
elastic submembers located between said
intersecting points being unbonded to any
of said sheets, and
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(5) portions of said first and second
elastic submembers that are laterally
outward from said intersecting points
being bonded to at least one of the
topsheet and the barrier sheet so as to
surround a leg opening.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention is illustrated by the
accompanying drawings, in which:
FIG. 1 is a perspective view showing garments of the
invention;
FIG. 2 is an exploded perspective view of the
components of the garment thereof;
FIG. 3 is a perspective view of a barrier sheet;
FIG. 4 is a perspective view, showing by way of
example, elastic members sandwiched between a backsheet
and the barrier sheet;
FIG. 5 is a perspective view showing a relatively
narrow barrier sheet; and
FIG. 6 is a sectional view illustrating the manner
in which the backsheet and the barrier sheet are bonded
to each other.
PREFERRED EMBODIMENT OF THE INVENTION
Now the garments of the invention will be described
by way of example in reference with the accompanying
drawings.
Referring to FIG. l, garments 1 have leg-openings 2
and a waist-opening 3 respectively provided with elastic
members 4, 5.
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Referring to FIG. 2, garments 1 comprise an elastic
water-permeable topsheet 6 made of nonwoven fabric, an
elastic water-permeable backsheet 7 made of the same
nonwoven fabric, a mat- or sheet-like absorbent core 8,
elastic members 4, 5 extending around the leg-openings
and the waist-opening, respectively, and an elastic
barrier sheet 9 made of elastomer film. The topsheet and
backsheet 6, 7 define together with the barrier sheet 9
between their front and rear zones 10, 11 a crotch zone
12 having both side edges formed with notches 13, 14, 15.
The barrier sheet 9 is bonded to the backsheet 7 over the
entire area thereof by means of hot melt type adhesive or
welding and the core 8 is intermittently bonded to the
top surface of the barrier sheet 9 by means of hot melt
type adhesive or welding. Bonding between the core 8 and
the barrier sheet 9 and bonding between the topsheet 6
and the barrier sheet 9 may be achieved either by a
plurality of dot-like bonding means 16 or by a plurality
of intermittent lines each having a suitable length. As
will be seen in FIG. 4, bonding between the backsheet 7
and the barrier sheet 9 may be also achieved by a
plurality of dot-like bonding means 17 (See FIG. 6) or by
a plurality of intermittent lines each having a suitable
length.
It is most preferable that the core 8 is bonded not
to the barrier sheet 9 but to the topsheet 6; and the
core 8 and the backsheet 7 and the barrier sheet 9 are
intermittently bonded to each other, respectively. In
this way, elasticity of the topsheet 6, the backsheet 7
and the barrier sheet 9 can be most efficiently utilized
and the hindrance of body fluid absorption by the core 8
can be avoided, which otherwise might occur due to
partially floating up of the topsheet 6 from the core 8.
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The barrier sheet 9 is provided along the both sides
in its front and rear zones 10, 11 with fine air vents 18
(See FIG. 3). It should be understood that these air
vents 18 may extend also through the top- and backsheets
6, 7.
The leg- and waist-elastic members 4, 5 are laid
along the notched edges 13, 15 of the topsheet 6 and
barrier sheet 9 as well as along both ends 19 of the
front and rear zones 10, 11. Each of the leg-elastic
members 4 comprises a first submember 4A and a second
submember 4B intersecting each other at points therealong
adjacent their opposite ends and their side sections
4A. sub. l, 4B1 extending from the respective
intersecting points to the respective ends are bonded by
hot melt type adhesive to the inner surface of the
topsheet 6 and/or the barrier sheet 9 along the notched
edges 13, 15 while their intermediate sections 4A2,
4B2 are positioned centrally under the core without
being bonded to any of the sheets. It should be
understood that these intermediate sections 4A2,
4B2 also may be bonded to anyone of said sheets.
Each of the waist-elastic members 5 is bonded by hot melt
type adhesive to the inner surface of the topsheet and/or
the barrier sheet 9 along the associated end 19.
The topsheet 6 and the barrier sheet 9 may be
bonded, if necessary, by heat seal ultrasonic welding or
hot melt type adhesive to each other along their outer
edges. The top surface of the core 8 also may be
intermittently bonded to the topsheet 6, if required. As
indicated by a chain line in FIG. 4, it is also possible
to sandwich the elastic members 4 between the backsheet 7
and the barrier sheet 9 and, in this case, said elastic
members are preferably bonded to the backsheet 7.
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The barrier sheet 9 shown by FIG. 5 has a width
corresponding to that defined between a pair of parallel
chain lines 20 in FIG. 3, namely, the portions extending
outside the respective chain lines 20 in FIG. 3 have been
cut off in the embodiment of FIG. 5. With such
embodiment, the ventilation is assured through the both
side areas of the topsheet and backsheets that are not
occupied by the barrier sheet 9.
A lamination 21 thus constructed is folded along a
longitudinally middle portion and intermittently bonded
together along the both side edges by heat seal or
ultrasonic welding means 22 into the garments as
illustrated in FIG. 1 so that these bonded side edges may
be manually torn open without effort.
It should be understood that the garments of the
invention may be provided in the form of well known open-
type garments as final product without being subjected to
the heat seal means or ultrasonic welding means 22 and in
such case the rear zone 11 (See FIG. 2) will be provided
along both side portions with fastener means such as the
tape fastener of well known art. Sometimes there is
provided no core 8, depending on particular types of
garments.
The topsheet and backsheet 6, 7 may be made of
nonwoven fabric which is elastic both in longitudinal and
transverse directions, the core 8 may be a hot
compression molded mixture of fluffy pulp, water
absorptive polymer particles and hot melt type fibre, the
barrier sheet 9 may be made of elastomer film being
elastic both in longitudinal and transverse directions,
and each of the elastic members 4, 5 may comprise at
least one string or ribbon of rubber or plastic film.
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Furthermore, said nonwoven fabric used as material
for the topsheet and backsheet 6, 7 is obtained
preferably by carding heat crimped fibre having a weight
perunit area of 25 to 45 g/m2 and a fineness of 0.5
to 3 d into web and heat-treating this web into a sheet .
Preferred example of said heat crimped fibre is that
supplied from Chisso Co., Ltd. in Japan under the trade
name of "EP FIBRE".
According to the present invention, the barrier
sheet interposed between the topsheet and backsheet both
of which are made of elastic nonwoven fabric, serves not
only to block leakage of liquid excretions but also to
enhance the fit of the garment's to the wearer's body
because the barrier sheet also has an elasticity and is
intermittently bonded to at least one of the topsheet and
backsheet so as to stretch and contract integrally with
one or both of the them.
Even when the barrier sheet is sandwiched between
the topsheet and backsheet over the entire area of these
topsheet and backsheet, the air vents provided in the
front and rear zones along the both sides of the barrier
sheet will prevent the interior of the garments from
becoming stuffy.
When there is provided the absorbent core, the close
fit serves, in cooperation with the sealing effect
provided by the leg- and waist-elastic members to further
effectively block the leakage of liquid excretions.
The barrier sheet is made of elastomer film which
is, unlike nonwoven fabric, substantially free from a
rapidly lowered contraction stress during stretching due
to loosened fibre entanglement and disjointed fibre
bonding, so said barrier sheet is very effective to
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maintain a desired contraction stress in the entire
material of the garments.
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