U.S. patent application number 09/297746 was filed with the patent office on 2002-02-28 for absorbent article with a raised portion.
Invention is credited to BJORKLUND, CAMILLA, DREVIK, SOLGUM, JOHNASSON, ANNELIE, SAMULESSON, ANN, WIDLUND, URBAN.
Application Number | 20020026170 09/297746 |
Document ID | / |
Family ID | 20404651 |
Filed Date | 2002-02-28 |
United States Patent
Application |
20020026170 |
Kind Code |
A1 |
SAMULESSON, ANN ; et
al. |
February 28, 2002 |
ABSORBENT ARTICLE WITH A RAISED PORTION
Abstract
The invention relates to an absorbent article intended for
female users, such as a sanitary napkin, or an incontinence guard,
having such a shape and size that it may be substantially
accommodated in the crotch region of a pair of panties and having a
longitudinal direction, a transverse direction and a thickness
direction. The article exhibits a liquid-pervious cover layer (2)
and a liquid-impervious cover layer (3) and further an absorbent
core consisting of at least one absorbent body (6), arranged
between the two surfaces (2, 3), and wherein a hump (16) is
arranged at the liquid-pervious cover layer (2) of the article. The
invention is characterized in that the hump (16) is substantially
shape permanent in the transverse direction of the article, both in
a wet and in a dry state, and to such an extent that the hump (16)
is not deformed in the transverse direction, either temporarily or
permanently, by the forces acting on the hump (16) during use of
the article.
Inventors: |
SAMULESSON, ANN; (LINDOME,
SE) ; JOHNASSON, ANNELIE; (GOTEBORG, SE) ;
BJORKLUND, CAMILLA; (MOLNLYCKE, SE) ; DREVIK,
SOLGUM; (MOLNLYCKE, SE) ; WIDLUND, URBAN;
(PIXBO, SE) |
Correspondence
Address: |
BURNS DOANE SWECKER & MATHIS L L P
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Family ID: |
20404651 |
Appl. No.: |
09/297746 |
Filed: |
September 1, 1999 |
PCT Filed: |
November 11, 1997 |
PCT NO: |
PCT/SE97/01886 |
Current U.S.
Class: |
604/385.01 |
Current CPC
Class: |
A61F 13/4702 20130101;
A61F 13/47227 20130101; A61F 13/4752 20130101 |
Class at
Publication: |
604/385.01 |
International
Class: |
A61F 013/15 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 15, 1996 |
SE |
9604221.3 |
Claims
1. An absorbent article intended for female users, such as a
sanitary napkin, or an incontinence guard, with such a shape and
size that it may be substantially accommodated in the crotch region
of a pair of panties and having a longitudinal direction, a
transverse direction and a thickness direction, wherein the article
exhibits a liquid-pervious cover layer (2), and a liquid-impervious
cover layer (3), and further an absorbent core consisting of at
least one absorbent body (6), arranged between the two cover layers
(2, 3), and wherein a hump (16) is arranged at the liquid-pervious
cover layer (2) of the article, characterized in that the hump (16)
is substantially shape permanent in the transverse direction of the
article, both in a wet and in a dry state, and to such an extent
that the hump (16) is not deformed in the transverse direction,
either temporarily or permanently, by the forces which act upon the
hump (16) during use of the article.
2. An article according to claim 1, characterized in that the hump
(16) is substantially shape permanent in the thickness direction of
the article, whereby the article will not be permanently deformed
by the pressure forces, acting in the thickness direction of the
article, which arise during normal use of the article.
3. An article according to any one of the preceding claims and
exhibiting two longitudinal side edges (11, 12; 711, 712),
characterized in that raised edge barriers (17, 18; 717, 718) are
arranged along the longitudinal side edges (11, 12; 711, 712).
4. An article according to claim 3, characterized in that the edge
barriers (717, 718) are formed by the arrangement of pre-tensioned
elastic members (712) mounted along the side edges (711, 712).
5. An article according to any one of the preceding claims,
characterized in that it comprises a shape-retaining element (5),
and that the hump (16) is formed by the shape-retaining element
(5).
6. An article according to claim 5, characterized in that the
shape-retaining element (5) consists of a layer of stiff plastic
material.
7. An article according to claim 5 or 6, characterized in that the
edge barriers (17, 18) are formed by the shape-retaining element
(5).
8. An article according to claim 5, 6 or 7, characterized in that
at least a first absorbent body (6) is arranged inside the
shape-retaining element (5), seen in a direction from the
liquid-pervious surface of the article, and that the
shape-retaining element (5) exhibits at least one through-going
aperture (19), within the region of the hump (16), through which
body fluid may pass into the first absorbent body (6).
9. An article according to any one of claims 5-8, characterized in
that an absorbent body (706) is arranged between the
shape-retaining element (705) and the liquid-pervious cover layer
(2) of the article.
10. An article according to any one of the preceding claims,
characterized in that the hump (16; 416; 716) is between 70 mm and
140 mm in the longitudinal direction of the article and preferably
between 80 mm and 120 mm.
11. An article according to any one of the preceding claims,
characterized in that the hump (16; 416; 716) has a base, facing
the liquid-impervious cover layer (3), and a top, facing the
liquid-pervious cover layer (2), whereby the extension of the hump
(16; 416; 716) in the transverse direction of the article is
between 2 mm and 25 mm at the base, preferably between 12 mm and 16
mm, and that the extension of the hump (16; 416; 716) in the
transverse direction at the top is between 3 mm and 10 mm,
preferably between 4 mm and 6 mm , and further that the hump (16;
416; 716) is wider at the base than at the top.
Description
TECHNICAL FIELD
[0001] The invention relates to an absorbent article, intended for
female users, such as a sanitary napkin or an incontinence guard,
with such a shape and size that it may be substantially
accommodated in the crotch region of a pair of panties and having a
longitudinal direction, a transverse direction and a thickness
direction, wherein the article exhibits a liquid-pervious surface,
and a liquid-impervious surface, and further an absorbent core
consisting of at least one absorbent body arranged between the two
surfaces, and wherein a hump is arranged at the liquid-pervious
surface of the article.
BACKGROUND OF THE INVENTION:
[0002] A common problem associated with absorbent articles of the
herein intended type is leakage of body fluid past the longitudinal
side edges of the article. Such leakage is of course extremely
undesirable, since it entails the risk of soiling the clothing of
the user. Because of the fairly insignificant extension of the
article also in the longitudinal direction, it is furthermore not
unusual that liquid leaks out forwards and backwards past the end
edges of the article. Thereby, a particular problem is leakage
backwards which usually arises in connection with the user lying
down, for example during the night.
[0003] The most frequent reason for edge leakage is that the
absorbent article is deformed during use, when the article is
squeezed between the thighs of the user. In this way, wrinkling
arises in an uncontrollable manner both in the absorbent core of
the article and in its cover material.
[0004] Such wrinkling results in the formation of channels on the
surface of the article, in which body fluid may seep out past the
side edges. Furthermore, the compression of the article implies
that the area accessible for liquid reception is reduced, whereby
the risk of body fluid ending up beside the article is
significant.
[0005] A further problem in connection with the previously known
absorbent articles is that the side edges of the articles risk
being folded in over the liquid-pervious surface of the article
because of the action from the body forces which arise when the
user moves about. The area accessible for liquid reception is also
drastically reduced by such folding in, since only a narrow
liquid-pervious region is thereby left between the inwardly-folded
side edges.
[0006] One way of reducing the risk of edge leakage caused by
deformation of the article during use is to provide the article
with a pre-formed hump, which during use is intended to be in
contact with the genitals of the user. Excreted body fluid may in
this way be caught as soon as it leaves the body of the user and
immediately be absorbed into the article without flowing out across
the surface thereof.
[0007] Previously known absorbent articles provided-with a
liquid-receiving hump are, however, afflicted with a number of
disadvantages.
[0008] A common way of creating a hump has been to simply build it
up by arranging a larger amount of absorbent material within the
area of the hump. Since the most commonly occuring absorbent
material is so-called cellulose fluff pulp, such a hump, however,
collapses and loses its shape when wetted. In order to achieve a
hump which is sufficiently large also in a wet state, a hump
consisting of cellulose fluff pulp must comprise so much absorbent
material that it becomes far too high, hard and uncomfortable to
wear in a dry state.
[0009] In order to solve the problem with large, hard and
uncomfortable humps, it has been suggested in EP 0 339 041 that the
liquid-impervious surface of the article be provided with
transverse elastic members. Such elastic members impart a certain
resiliency to the article if it is subjected to flattening. The
elastic members, however, do not to any great extent prevent
compression and undesired deformation in the transverse direction
of the article.
[0010] In another publication, EP 0 419 434, it has been suggested
to create a soft hump on an absorbent article by means of locking
the side edges of the article at a mutual distance which is smaller
than the planar distance between the side edges. Neither does this
previously known article, to any appreciable extent, resist such
deformation which is caused by the article being affected by
pressure and shear forces during use.
[0011] In EP 0 335 252 and EP 0 335 253 it has been suggested to
provide an absorbent article with a deformation element. The
deformation element is affected by the transverse compressive
forces between the thighs of a user. The purpose of the deformation
element is that this during use should curve a portion of the
article in a direction towards the body of the user. However, it is
impossible to completely control, or anticipate the shape the
article will adopt for each individiual user. Furthermore, it is
not possible to ensure the contact between the body of the user and
the surface of the article, since the degree of bulging is
completely determined by how much the article is compressed in a
transverse direction.
[0012] Thus, there remains a need for a leakage-proof absorbent
article, which has a predictable shape, both before and during use,
and which maintains its shape independently of the movements of the
user and of the wetting the article is subjected to.
[0013] An article designed according to the invention, of the type
disclosed in the introduction, is primarily characterized in that
the hump is substantially shape permanent in the transverse
direction of the article both in a dry and in a wet state, and to
such an extent that the hump is not deformed in the transverse
direction, either temporarily or permanently, by the forces which
act on the hump during use of the article.
[0014] Further variants and embodiments are evident from the
following claims.
[0015] Since the article is provided with a hump which is shape
permanent both in a wet and in a dry state, it is possible to
predict the shape of the hump in every situation. The fact that the
hump is shape permanent implies that it remains essentially
unaffected in normal use and is not deformed when it is subjected
to pressure and shear forces which arise in use. It is particularly
important that the hump is not compressed in the transverse
direction, between the thighs of the user. It is, however, in
general also an advantage if the hump is substantially
incompressible also in the thickness direction.
[0016] The height of the hump above the surface of the absorbent
article must be adapted so that good contact between the body of
the user and the hump is ensured during use. Since the hump is so
hard or stiff that it is essentially unyielding to the forces it is
subjected to during use it is, however, important that the hump is
not so high that it presses against the body of the user and
thereby causes discomfort during use. Furthermore, it is necessary
to ensure that the hump does not chafe against the sensitive soft
parts in the crotch of the user. Thereby, it has been found that a
hump which at its highest part projects at least 5 mm from the
surface of the article, but not more than 20 mm, fulfils the
requirements both of good body contact and high user comfort.
[0017] A hump in accordance with the invention is relatively
narrow, suitably between 2 mm and 25 mm at the base and preferably
between 12 mm and 16 mm. At the top the hump is suitably between 3
mm and 10 mm wide and preferably between 4 mm and 6 mm. The hump is
designed with a substantially triangular cross-section and is,
consequently, wider at the base than at the top. Since the hump is
comparatively narrow, it can protrude, without any discomfort to
the user, slightly in between the labia pudendi of the user.
Thereby, it is an advantage if the hump slightly separates the
labia pudendi, since the liquid transfer from the user to the
article is thus facilitated.
[0018] At the rear portion of the hump, it should have such a shape
that it is in close contact with the body of the user, in the
region behind the vaginal opening. Thereby, it is avoided that body
fluid leaks backwards in the furrow between the buttocks of the
user and leaks out from the article. As earlier mentioned, such
leakage backwards is particularly embarrassing when the user is
lying down. In a corresponding way, the front portion of the hump
should conform to the body shape of the user in the region in front
of the vaginal opening.
[0019] It is important that the body fluid which is emitted is
immediately caught and absorbed into the hump. Liquid is thus
prevented from collecting between the body of the user and the
hump. When the user stands up or otherwise moves about, there is a
risk that a gap will arise at the front portion of the hump,
between the hump and the body of the user. If a large quantity of
unabsorbed liquid has been trapped between the body of the user and
the surface of the article, such liquid may then flow out through
the gap. Such sudden liquid flows are extremely undesirable, partly
because the user perceives them as unpleasant, and partly because
they considerably increase the risk of leakage.
[0020] The length of the hump is furthermore of importance to the
achievement of optimum contact between the hump and the body of the
user. The hump should have such a shape and extend so far backwards
on the article that it essentially seals against liquid flow
backwards on the article. This is achieved by means of the hump
being in sealing contact against the skin behind the vaginal
opening of the user. A suitable length of the hump has thereby been
found to be between 70 mm and 140 mm, preferably between 80 mm and
120 mm. The hump should not extend across the entire length of the
article and, in particular, it is advantageuous if a portion at the
front end of the article is free from the stiff, shape permanent
hump. In this way, the front end may bend and conform to the
curvature on the body of the user.
[0021] In order to conform to the anatomy of the user, the hump
should be highest at the portion of the article which is intended
to be in contact with the vaginal opening of the user. From the
highest portion, the height should gradually decrease in a
direction towards the end portions of the article. Thereby, the
hump should extend backwards from the highest portion between 5 mm
and 40 mm and preferably between 10 mm and 30 mm. In front of the
highest portion, the hump should have a length of between 50 mm and
90 mm, preferably between 55 mm and 80 mm.
[0022] A raised edge barrier may advantageously be arranged at both
sides of the central hump. The edge barriers increase the
leakage-security of the article by serving as seals against the
groin of the user. Raised edge barriers can be achieved in a number
of different ways. Preferably, the edge barriers are made of the
same material as the central hump and thereby have essentially the
same resistance to deformation as the hump. However other types of
edge barriers, such as elastic side edges, foam rubber strips,
wadding, or the like, are conceivable. The edge barriers may either
be purely physical barriers, or prevent liquid passage by means of
absorbing body fluid.
SHORT DESCRIPTION OF THE DRAWINGS:
[0023] The invention will in the following be described in greater
detail with reference to the figures which are shown in the
attached drawings.
[0024] FIG. 1 shows a plan view of a sanitary napkin in accordance
with the invention, seen from the side which in use is facing the
user,
[0025] FIG. 2 shows a section along the line II-II through the
sanitary napkin in FIG. 1,
[0026] FIG. 3 shows a longitudinal section along the line III-III
through the sanitary napkin in FIG. 1.
[0027] FIG. 4 shows a plan view of a sanitary napkin according to a
second embodiment of the invention, seen from the side which in use
is facing the user,
[0028] FIG. 5 shows a cross-section along the line V-V through the
sanitary napkin FIG. 4,
[0029] FIG. 6 shows a portion of the absorbent core in the sanitary
napkin of FIG. 4 seen from the side which in use is facing the
user,
[0030] FIG. 7 shows a sanitary napkin according to a third
embodiment of the invention, seen from the side which in use is
facing the user and
[0031] FIG. 8 shows a cross-section along the line VII-VII through
the sanitary napkin in FIG. 7.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS:
[0032] The sanitary napkin 1 shown in FIGS. 1 and 2 comprises a
liquid-pervious cover layer 2, arranged on the side of the sanitary
napkin 1 which during use is intended to be facing the user. The
liquid-pervious cover layer 2 suitably consists of soft,
skin-friendly material. Examples of useful liquid-pervious cover
materials are different types of non-woven fibre fabrics, so-called
nonwoven materials. Other occurring liquid-pervious cover materials
are perforated plastic films, scrims, knitted or woven fabrics, and
combinations and laminates of the listed material types.
[0033] The sanitary napkin 1 further comprises a liquid-impervious
cover layer 3, arranged at the side of the sanitary napkin 1 which
during use is intended to be facing away from the user. Usually, a
thin plastic film is used as a liquid-impervious cover layer 3. It
is, however, also possible to use liquid-pervious material layers
which are coated with a liquid-impervious material. Other
treatments, such as thermo-calendering in order to fuse an
originally liquid-pervious material into a substantially
liquid-impervious layer, may also be utilized. It is furthermore
possible to use nonwoven materials, or other textiles which are
sufficiently dense and the fibres of which are sufficiently
hydrophobic that they may function as a liquid barrier layer.
[0034] The two cover layers 2, 3 are mutually interconnected and
form a protruding connecting edge 4 around the periphery of the
sanitary napkin. The connection between the cover layers 2, 3 may
be achieved by means of any previously known technique suitable for
the purpose, such as gluing, welding or sewing.
[0035] Between the cover layers 2, 3, in a direction from the
liquid-pervious cover layer 2 towards the liquid-impervious cover
layer 3, there is a shape-retaining element 5, a first absorbent
body 6, and a second absorbent body 7.
[0036] The sanitary napkin 1 is hourglass-shaped, with relatively
wider front portion 8 and rear portion 9, and with a narrower
intermediate crotch portion 10. The sanitary napkin 1 furthermore
exhibits two longitudinal concavely-curved side edges 11, 12, and
also two convexly-curved end edges 13, 14.
[0037] An attachment member 15, in the form of a longitudinal
rectangular region of self-adhesive glue, is arranged on the
surface of the liquid-impervious cover layer 3 which is turned away
from the user. The attachment member 15 extends across the greater
part of the surface of the liquid-impervious cover layer 3, between
the two end edges 13, 14. It is of course possible to use other
glue patterns, such as longitudinal stripes, transverse regions,
dots, circles, or other designs. Moreover, the invention is not
limited to adhesive attachment members, but frictional attachment
devices such as snap fasteners, clips, girdles, pants, or the like
may be utilized where suitable. The extension and location of the
shape-retaining element 5, corresponds on the whole, to the shape
and the dimension of the crotch portion 10 of the sanitary napkin
1. The shape-retaining element 5 has a predetermined,
three-dimensional shape with a central hump 16, extending in the
longitudinal direction of the sanitary napkin, and two raised edge
barriers 17, 18, arranged along the side edges 11, 12 of the
sanitary napkin 1, on each side of the central hump. The central
hump 16 and the edge barriers 17, 18 project from the plane of the
sanitary napkin on the side of the sanitary napkin which during use
is intended to be facing the user. Thereby, the intention is that
the central hump 16 should be in contact against the body of the
user and be partly inserted between the outer labia pudendi of the
user. The edge barriers 17, 18 are situated in the groin of the
user during use and seal against leakage past the side edges 11, 12
of the sanitary napkin.
[0038] The central hump 16 has an elongated shape and tapers in a
direction towards the end portions 8, 9 of the sanitary napkin 1.
Thereby, the hump is highest at the region which during use is
intended to be in contact with the vaginal opening of the user. The
length of the hump is suitably approximately 115 mm, but may if
desired vary between 70 mm and 140 mm. Thereby, the hump suitably
extends approx. 20 mm backwards from the highest portion and
approx. 75 mm forwards from the highest portion. Also these
measures may, however, be varied within the above-mentioned
limits.
[0039] Within the region of the hump 16, both the shape-retaining
element 5 and the liquid-pervious cover layer 2 are provided with a
plurality of apertures 19, or perforations, which allow liquid
passage into the first absorbent body 6, situated in the
shape-retaining element 5 inside the hump 16. When using such a
perforated shape-retaining element, the liquid-pervious cover layer
2 may be omitted, at least within the region of the hump 16.
Generally, however, for reasons of comfort it is desirable to cover
the stiff, hard shape element with a softer material.
[0040] The shape-retaining element 5 is designed in a shape
permanent, stiff sheet material such as hard plastic, stiff paper,
cardboard, a stiff nonwoven material, laminate, or the like. It is
essential for the invention that the shape-retaining element 5, at
least in the transverse direction, is sufficiently shape permanent
that the central hump 16 during use substantially resists the
compression forces from the thighs of the user, without being
either temporarily or permanently deformed. It is suitable, but not
necessary, that the central hump 16 also resists compression in the
thickness direction. The degree of deformability of the central
hump 16 in the thickness direction is decided by the material
stiffness of the shape-retaining element 5 in combination with the
number of apertures 19 in the hump 16, and also the size of the
apertures 19. At the same basic stiffness of the material in the
shape-retaining element 5, the deformability increases with the
number of apertures 19 as well as with the size of the apertures
19. Furthermore, the stiffness of the hump 16 is influenced by the
stiffness of the absorbent material which is arranged inside the
hump.
[0041] The first absorbent body 6, arranged inside the
shape-retaining element 5, is situated inside the central hump 16.
Due to the shape of the sanitary napkin, with the central hump 16,
the sanitary napkin is maintained in contact with the body of the
user during use. The fluid which is emitted is therefore
immediately caught by the hump 16 and passes through the apertures
19 in the shape-retaining element 5 into the first absorbent body
6. Since the first absorbent body 6 is intended to receive and
absorb almost all emitted body fluid, the absorption capacity of
the first absorbent body should correspond to the total liquid
amount which the sanitary napkin is estimated to absorb during
use.
[0042] In the cross-sectional FIGS. 2 and 3, the first absorbent
body 6 is shown as a fibre wadding containing particles of
super-absorbent material, evenly distributed in the fibre
structure. Super-absorbent material refers to polymers which are
available in the form of fibres, flakes, particles, granules, or
the like and which are able to absorb several times their own
weight of body fluid during swelling and forming of a gel. A
particular advantage with the use of super-absorbent material in
connection with the sanitary napkin shown in FIGS. 1-3, is that the
space available for absorbent material in the central hump 16 is
fairly limited. By utilizing super-absorbent material, it is
possible to build in a large absorption capacity, even in the
comparatively small space beneath the central hump 16 in the
shape-retaining element 5.
[0043] Other suitable absorbent materials for use in the first
absorbent body 6 are for example cellulose fluff pulp, cotton,
absorbent foam material, or the like.
[0044] For maximum utilization of the absorption capacity of the
absorbent material, it is necessary to ensure that there is
sufficient space for expansion during absorption. By using a
liquid-impervious cover layer 3, which has a certain flexibility
and elasticity, the super-absorbent material may expand both so
that it fills up the central hump, and, by stretching the
liquid-impervious cover layer 3, so that a bulge is formed on the
side of the sanitary napkin 1 which is facing away from the
user.
[0045] The absorbent material in the first absorbent body 6 may
further consist of a mixture of absorbent and non-absorbent
material. An example of such a mixture is a non-absorbent fibre
structure with bonded super-absorbent fibres or particles.
[0046] A type of absorbent material which has been found to be
particularly suitable for use in the first absorbent body, are
those fibre materials which are described in WO 94/10953 and WO
94/10956. Since the shape-retaining element 5 prevents the
absorbent material from swelling in a direction towards the body of
the user, the hump 16 maintains its shape against the user during
use. However, it is possible to use material which swells when it
absorbs liquid. The first absorbent body may thereby be allowed to
expand in a direction away from the body of the user, since the
liquid-impervious cover layer 3 is resilient and admits such
expansion.
[0047] The second absorbent body 7 is arranged between the first
absorbent body 6 and the liquid-impervious cover layer 3. The
second absorbent body 7 has a fairly limited absorption capacity in
comparison with the first absorbent body 6. Due to this, the second
absorbent body 7 primarily serves as a reserve which is made use of
for absorption when the first absorbent body 6 has been saturated
with liquid. The second absorbent body 7 also has the ability to
absorb a minor amount of liquid such as perspiration or occasional
droplets which may happen to trickle out to the end portions 8, 9
of the sanitary napkin 1. Furthermore, the second absorbent body 7
increases the stability in the soft, pliable end portions 8, 9, and
makes the sanitary napkin softer against the body of the user.
[0048] The absorbent material in the second absorbent body 7 is
suitably constituted by one, or several, layers of a conventional
absorbent material. Examples of useful materials are tissue layers,
wadding layers of synthetic or natural fibres, layers of cellulose
fluff pulp, absorbent foam layers, or the like.
[0049] In the sanitary napkin 1, in FIGS. 1-3, the good contact
between the hump 16 and the body of the user ensures that
substantially no body fluid flows out towards the sides from the
hump 16. If, in spite of this, a small quantity of body fluid
should pass out towards the side edges of the sanitary napkin,
leakage is efficiently prevented by means of the raised edge
barriers 17, 18. The edge barriers 17, 18 conduct the liquid
forwards, or backwards to the edge portions 8, 9 of the sanitary
napkin, where it may enter through the liquid-pervious cover layer
2 into the second absorbent body 7, situated on the inside. If
found to be desirable, it is of course possible to arrange a small
quantity of absorbent material inside the liquid-pervious cover
layer 2, between the edge barriers 17, 18 and the central hump 16,
in order to prevent liquid from flowing on the surface of the
sanitary napkin.
[0050] The sanitary napkin 401, shown in FIGS. 4 and 5, has the
same general structure as the sanitary napkin 1, shown in FIGS.
1-3. However, the sanitary napkin 401 in FIGS. 4 and 5 lacks a
special shape-retaining element. Accordingly, the sanitary napkin
401 comprises a liquid-pervious cover layer 402, a
liquid-impervious cover layer 403, and a first absorbent body 406
and a second absorbent body 407, enclosed between the cover layers
402, 403. The cover layers 402, 403 are mutually interconnected
around the absorbent bodies 406, 407 and thereby form a connecting
edge 404 around the periphery of the sanitary napkin 401.
[0051] The sanitary napkin 401 has a trapezium shape, with a wider
front portion 408, a narrower rear portion 409, and an intermediate
centre portion 410. Furthermore, the sanitary napkin 401 has two
oblique side edges 411, 412, which extend between two almost
straight end edges 413, 414.
[0052] An adhesive attachment member 415 is arranged in the form of
three glue lines, travelling in the longitudinal direction of the
sanitary napkin 401, on the liquid-impervious cover layer 403.
[0053] An elongated hump 416 is arranged centrally in the
longitudinal direction of the sanitary napkin 401. The hump 416 is
widest at the centre portion 410 of the sanitary napkin and tapers
in a direction towards the front and the rear portions 408, 409.
Furthermore, it is suitable that the hump 416 is profiled in the
longitudinal direction, so that it is highest at the centre portion
410 and gradually decreases in height in a direction towards the
end portions 408, 409.
[0054] The hump 416 is constituted by a plurality of
willowleaf-shaped layers 420 of a highly absorbent fibre material.
The willowleaf-shaped layers 420 together constitute the first
absorbent body 406 of the sanitary napkin 401, which consequently
constitutes the hump 416.
[0055] FIG. 6 shows the first absorbent body 406. The absorbent
body 406 is seen from the side which during use is facing the user.
In order to obtain the desired ridge-like shape of the absorbent
body 406, the integral layers 420 of absorbent material have been
stacked on each other. Thereby, the layer 420, which in FIG. 6 is
situated furthest away from the viewer, has the largest extension,
whereafter the layers 420 diminish in area in a direction towards
the viewer. The layers 420 are nearly congruent and are arranged
concentrically in relation to each other. As a consequence, the
first absorbent body 406 is imparted a stepped cross-sectional
profile.
[0056] A shape of a similar kind is achieved by arranging the
layers 420 in reversed order, with the smallest layer at the bottom
and gradually increasing layer dimensions in a direction towards
the top of the hump. In such an arrangement, the larger layers are
draped over the smaller layers, so that the final result is a hump
which tapers towards the top.
[0057] Another way of achieving an absorbent body 406 with a
suitable shape, is by rolling together a triangular blank of an
absorbent material. The blank has the shape of an isosceles
triangle and is rolled together from the base towards the corner
between the two edges having equal length. By means of this method,
the resulting absorbent body becomes spool-shaped, with a thicker
centre portion and narrower end portions.
[0058] A further way of achieving an absorbent body having the
desired shape is by placing a number of plates, or material layers,
of an absorbent material on end. By choosing a suitable absorbent
material it is thereby possible to achieve an absorbent body with a
very good shape permanence both in a transverse and in a vertical
direction.
[0059] A suitable material for the absorbent body shown in FIG. 6
is the absorbent material which is disclosed in WO 94/10956. This
material is a dry-formed fibre layer with high density and
stiffness, which is used directly in an absorbent article, without
first being defibered. Another similar material, with particularly
suitable properties for blood-absorption purposes,, is disclosed in
WO 94/10953. The materials disclosed in WO 94/10956 and 94/10953
both have sufficient stiffness and ability to resist pressure
deformation, in order to provide the central hump 416 on the
sanitary napkin 401 in FIG. 4 with the desired shape stability.
Furthermore, these fibre materials have a very good absorption
capacity. During absorption the material swells slightly in the
thickness direction and in this way conforms to the available space
in the crotch of the user. An advantage with this is that the hump
416 during use adopts a shape which is uniquely adapted to each
respective user. In this way, both the leakage security and the
user comfort are increased.
[0060] The second absorbent body 407 of the sanitary napkin 401 is
located between the first absorbent body 406 and the
liquid-impervious cover layer 403. The second absorbent body 407
primarily constitutes a protection against edge leakage around the
central hump 416. Secondly, it also serves as an additional
absorption capacity which can be made use of if the first absorbent
body 406 is saturated by unexpectedly large liquid quantities.
Furthermore, the second absorbent body 407 is responsible for
providing the sanitary napkin 401 with an extension length in the
plane, so that the sanitary napkin 401 may be attached inside a
pair of panties by means of the attachment member 415 arranged on
the liquid-impervious cover layer 403.
[0061] The sanitary napkin 701, shown i FIG. 7, comprises a
liquid-pervious cover layer 702, a liquid-impervious cover layer
703, which are mutually interconnected within a connection edge 704
around the periphery 701 of the sanitary napkin 701.
[0062] The sanitary napkin 701 is hourglass-shaped, with two end
portions 708, 709 and a narrower centre portion 710. Furthermore,
the sanitary napkin 701 exhibits two longitudinal side edges 711,
712 and two transverse end edges 713, 714.
[0063] A shape-providing material layer 707, having substantially
the same shape and dimensions as the sanitary napkin 701 as a
whole, is arranged between the two cover layers 702, 703. The
material layer 707 is substantially non-absorbent, soft and
resilient. The main purpose of the material layer 707 is to provide
the sanitary napkin 701 with the shown hourglass-shape. Since the
material layer 707 has a certain resiliency, both in the thickness
direction and in the plane of the layer, the material layer 707
also provides user comfort and shape permanence in the sanitary
napkin 701.
[0064] A shape-retaining element 705, of the kind which is shown in
FIGS. 1-3, is arranged at the centre portion 710 of the sanitary
napkin 701. Accordingly, the shape-retaining element 705 is made
from a material which is so stiff that it essentially completely
resists compression during use. The shape-retaining element 705 is
not deformable, either in the cross direction or in the thickness
direction, when it is subjected to the body forces which arise
during normal use.
[0065] The shape-retaining element 705 is constituted by an almost
rectangular material piece, which in the transverse direction of
the sanitary napkin ends a distance inside of the side edges 711,
712 of the sanitary napkin 701. In the longitudinal direction of
the sanitary napkin, the shape-retaining element 705 extends only
across the centre portion 710. A longitudinal, ridge-like hump 716,
is formed centrally on the shape-retaining element 705. The hump
716 is lower closest to the end portions 708, 709 than at the
central part of the centre portion 710.
[0066] An absorbent body 706, consisting of one or several layers
of absorbent material is arranged over the hump 716, between this
and the liquid-pervious cover layer 702. The absorbent material may
be selected in the same way as the absorbent material in the humps
16, 416, described in connection with FIGS. 1-6.
[0067] Raised edge barriers 717, 718 are arranged along the side
edges 711, 712 of the sanitary napkin 701. The edge barriers 717,
718 are formed by means of elastic members 721 being attached in a
stretched condition between the two cover layers 702, 703, along
the side edges 711, 712 at the centre portion 710 of the sanitary
napkin. The elastic members 721 may be of any conventional kind,
such as elastic bands, threads, elastic nonwoven material, or the
like. The elastic members 721 may of course optionally be attached
to the outside of one of the cover layers 702, 703, or be
constituted by a band of an elastic foam material, elastic nonwoven
material, or the like, which has been folded around the connection
edge 704 formed by the cover layers 702, 703. A number of different
ways of attaching elastic members 721 to one or two material layers
are previously known, and may be used in order to achieve the
raised edge barriers 717, 718.
[0068] The sanitary napkin is furthermore, in a conventional way,
provided with attachment members 715, in the form of two
longitudinal stripes of self-adhesive, pressure-sensitive glue.
[0069] The invention has in the foregoing been described in
connection with sanitary napkins. However, it is possible to
utilize the invention also for other absorbent articles which are
intended to be worn by female users. Accordingly, the invention
also embraces panty-liners and incontinence guards for women.
[0070] The invention should not be regarded as being limited to the
herein described embodiments, but a number of further variants and
modifications are conceivable within the scope of the claims.
Furthermore, all conceivable combinations of the described
embodiments are intended to be embraced by the invention.
* * * * *