U.S. patent application number 13/455804 was filed with the patent office on 2013-05-16 for absorbent body for an absorbent article and method of producing an absorbent body.
This patent application is currently assigned to HAKLE-KIMBERLY DEUTSCHLAND GMBH. The applicant listed for this patent is Franz Aschenbrenner, Maria Raidel, Jan Ullmann. Invention is credited to Franz Aschenbrenner, Maria Raidel, Jan Ullmann.
Application Number | 20130123088 13/455804 |
Document ID | / |
Family ID | 7918313 |
Filed Date | 2013-05-16 |
United States Patent
Application |
20130123088 |
Kind Code |
A1 |
Raidel; Maria ; et
al. |
May 16, 2013 |
ABSORBENT BODY FOR AN ABSORBENT ARTICLE AND METHOD OF PRODUCING AN
ABSORBENT BODY
Abstract
A method of producing an absorbent body includes the steps of
passing a first cut-out from a first web material through a nip and
passing a second web material through the nip whereby the cut-out
from the first web material overlays the second web material as the
cut-out and the second web material pass through the nip. One of
the following is performed as the cut-out from the first web
material and the second material together pass through the nip:
forming a fold line in the second web material at the peripheral
edge of the cut-out of the first web material and forming a second
cut-out from the second web material having substantially the same
shape as the first cut-out from the first web material.
Inventors: |
Raidel; Maria; (Nurnberg,
DE) ; Aschenbrenner; Franz; (Kastl, DE) ;
Ullmann; Jan; (Nurnberg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Raidel; Maria
Aschenbrenner; Franz
Ullmann; Jan |
Nurnberg
Kastl
Nurnberg |
|
DE
DE
DE |
|
|
Assignee: |
HAKLE-KIMBERLY DEUTSCHLAND
GMBH
Mainz
DE
|
Family ID: |
7918313 |
Appl. No.: |
13/455804 |
Filed: |
April 25, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10049891 |
Jul 8, 2002 |
8187242 |
|
|
PCT/EP00/07836 |
Aug 11, 2000 |
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13455804 |
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Current U.S.
Class: |
493/454 |
Current CPC
Class: |
A61F 2013/4581 20130101;
A61F 13/15699 20130101; A61F 13/539 20130101; A61F 13/474
20130101 |
Class at
Publication: |
493/454 |
International
Class: |
A61F 13/15 20060101
A61F013/15 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 13, 1999 |
DE |
199 38 437.1 |
Claims
1. A method of producing an absorbent body for an absorbent article
of the type worn by a wearer and having an absorbent body disposed
generally centrally of said article and adapted for absorbing
liquid body waste released by the wearer, the method comprising the
steps of: passing a first cut-out from a first web material through
a nip; passing a second web material through the nip whereby the
cut-out from the first web material overlays the second web
material as the cut-out and the second web material pass through
the nip; and performing one of the following as the cut-out from
the first web material and the second material together pass
through the nip: forming a fold line in the second web material at
the peripheral edge of the cut-out of the first web material and
forming a second cut-out from the second web material having
substantially the same shape as the first cut-out from the first
web material.
2. A method as set forth in claim 1 wherein the nip is defined by a
pair of conveyor elements, the step of passing the second web
material through the nip comprising conveying the second web
material over one of said conveyor elements to pass therebetween,
at least one of said conveyor elements having one of a fold-line
forming device and a cutting device mounted thereon for contacting
the second web element at the peripheral edge of the cut-out from
the first web-material generally within the nip.
3. A method as set forth in claim 2 wherein the pair of conveyor
elements are second and third conveyor elements defining the nip
therebetween, the second conveyor element having said one of a
fold-line forming device and a cutting device mounted thereon, the
method further comprising the steps of conveying a first web
material over a first conveyor element to a nip defined by the
first conveyor element and the second conveyor element, and
contacting the first web of material with said one of a fold-line
forming device and a cutting device mounted on the second conveyor
element with sufficient pressure to form the first cut-out from the
first web material as the first web material passes through the nip
formed by the first and second conveyor elements, the step of
passing the first cut-out from the first web of material through
the nip comprising supporting the first cut-out on the second
conveyor element upon rotation of the second conveyor element to
convey the first-cut out to the nip formed by the second and third
conveyor elements.
4. A method as set forth in claim 3 wherein the first and second
conveyor elements are rotating elements from the group consisting
of rollers and wheels, the first web of material being conveyed
through the nip defined by the first and second conveyor elements
at a speed equal to the rotational speed of the second conveyor
element.
5. A method as set forth in claim 3 wherein the first and second
conveyor elements are rotating elements from the group consisting
of rollers and wheels, the first web of material being conveyed
through the nip defined by the first and second conveyor elements
intermittently while the second rotating conveyor element rotates
continuously.
6. A method as set forth in claim 1 further comprising the step of
applying adhesive to at least one of the first cut-out from the
first web material and the second web material prior to passing the
first cut-out and the second web material through the nip such that
the first cut-out is secured to the second web material upon
passing through said nip.
7. A method as set forth in claim 3 wherein the step of supporting
the first-cut on the second conveyor element as the first cut-out
is conveyed to the nip formed by the second and third conveyor
elements comprises applying a vacuum pressure to the first cut-out
to hold the first cut-out on the second conveyor element during
rotation of the second conveyor element.
8. A method as set forth in claim 7 wherein the first cut-out is
released from the second conveyor element onto the second web
material by subjecting the first cut-out to a positive pressure.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/049,891 filed Jul. 8, 2002, which is hereby
incorporated by reference in its entirety.
BACKGROUND
[0002] The present invention concerns an absorbent article
comprising a segmented absorbent body and a method of producing an
absorbent body, in particular a segmented absorbent body. The
absorbent body is preferably arranged between a liquid-permeable
cover layer and a liquid-impermeable backing layer.
[0003] It is known from the state of the art how to produce
absorbent articles containing the absorbent bodies. As a rule,
these absorbent bodies are arranged between a liquid-permeable
cover layer and a liquid-impermeable backing layer. Such absorbent
articles include, for example, menstrual hygiene napkins,
disposable diapers, training diapers and incontinence articles for
adults as well as similar articles. As a rule, the absorbent bodies
of the traditional type contained in these absorbent articles
contain pulped cellulose or sheeting materials of
cellulose/synthetic fiber blends as the absorbent material.
[0004] These materials are supposed to serve to absorb body fluids
such as menstrual fluid and retain them in a napkin. The menstrual
fluid should preferably remain inside the absorbent article even
under pressure and if possible it should not be detectable from the
outside. The absorbent article and in particular the absorbent body
in the absorbent article should prevent the secreted body fluids
from soiling the wearer's body and/or spotting the adjacent items
of clothing.
[0005] The sheeting materials used for the absorbent material are
either arranged continuously (i.e., they cover the total length of
the napkin or they form rectangular inserts, for example) or they
may have cutouts. The cutouts are preferably arranged in a top
layer of the absorbent material and should serve to convey the
fluid away from the body of the wearer of the absorbent article as
rapidly and efficiently as possible and to release it downward into
the other absorbent and storing layers of the absorbent
article.
[0006] There are several possibilities of storing the fluid
delivered in the absorbent article. One of these possibilities is
to convey the fluid secreted as rapidly and directly as possible to
a lower area of the article which is preferably arranged directly
above the liquid-impermeable backing layer, from whence the fluid
is then distributed in the longitudinal direction. As soon as this
bottom absorbent distributor layer becomes saturated with the fluid
secreted, the absorbent layers closer to the wearer's body then
become saturated with the fluid.
[0007] Another possibility is for the secreted body fluid to be
distributed as rapidly as possible in the longitudinal directions
of the napkin, from whence in the remaining course it then diffuses
toward the side of the absorbent article facing away from the
wearer's body.
[0008] Apart from providing a cutout in an upper area of the
absorbent material in an absorbent article, there are various other
possibilities for improving the distribution of fluid in an
absorbent article. These possibilities involve, for example,
providing various layers within the absorbent article to function
as flow layers, storage layers, transfer layers or distributing
layers. Such layers may be defined by different materials, for
example. Another possibility is to provide embossed lines in a
layer of the absorbent material in an absorbent article through
which the fluid is guided in predetermined and preferred paths,
thus preventing the area of the absorbent article exposed to the
fluid from becoming saturated.
[0009] Another possibility of preventing leakage and promoting
penetration of the secreted fluid into the interior of the
absorbent material is to provide elastic or elevated side areas
(cuffs) which should prevent leakage at the sides.
[0010] With the absorbent articles described above, it is also
important that the absorbent article is adapted to the shape of the
wearer's body, preferably conforming to the shape of the wearer's
body, so that the wearer is not hindered by the absorbent article.
It is especially preferable for the absorbent article not to be
perceived by the wearer at all. Furthermore, the absorbent article
should be prevented from rubbing against the wearer's body in a
manner that would be unpleasant for the wearer, even leading to red
and irritated skin. There have been various proposals for achieving
such an optimum suppleness and adaptability to the wearer's body.
Many of these proposals concern the use of materials that are
already rather supple anyway and therefore offer increased comfort
for wear. However, such materials are often less suitable than an
absorbent material for their actual function. A typical absorbent
material such as coform will have a certain stiffness which can be
reduced only by also surrendering certain advantageous absorbent
properties.
SUMMARY
[0011] One object of the present invention is to provide an
absorbent article that does not have the abovementioned
disadvantages according to the state of the art. In particular, one
object of the present invention is to provide an article that
prevents in particular leakage of secreted fluid into the side
areas of the absorbent article (side leakage) in an improved
manner.
[0012] Another object of the present invention is to provide an
absorbent article which permits especially good suppleness and
individual adaptation to the wearer's body.
[0013] Finally, another object of the present invention is to
reduce the stiffness of a continuous web of material in such a
manner that it leads to an improved suppleness and better
adaptation to the wearer's body.
[0014] The above-mentioned objects are achieved by the absorbent
article characterized in Claim 1, as well as by the method
characterized in Claim 29. Accordingly, an absorbent article is
provided, comprising an absorbent body having one or more layers,
where said absorbent body is segmented by at least one dividing
seam in at least some partial areas.
[0015] The term "segmented" as used here is understood to refer to
the subdivision of the absorbent body into subareas, i.e.,
segments, defined by at least one dividing seam.
[0016] The term "dividing seam" is understood to refer to the areas
of a material processed for separation. The term "processed for
separation" is understood here to refer to the separation methods
known in the state of the art by means of which individual areas of
a material layer can be separated from one another. "Processing for
separation" thus produces in general dividing seams in these
materials, e.g., punched or cut lines.
[0017] The dividing seam may consist of a continuous or interrupted
dividing line. If the dividing seam is executed in the form of an
interrupted dividing line, the different areas of material are
still joined together by bridge areas. In addition, a dividing seam
can be worked through the entire thickness of one or more layers of
material or through only partial areas of the thickness or one or
more layers of material. The latter is preferred if the layer of
material is still to form a unit.
[0018] Providing an absorbent body which is segmented by at least
one dividing seam in at least partial areas yields an absorbent
article which achieves optimum suppleness and individual adaptation
to the wearer's body. The segmentation, which forms intended
breaking points, eliminates or reduces the stiffness of the
absorbent material in an inventive manner, leading to improved
suppleness. In addition, the dividing seams improve the rapid
penetration of the secreted fluid into the depth of the absorbent
body, thus preventing side leakage in an improved manner and
thereby also preventing soiling of the wearer's body and/or
clothing.
[0019] The dividing seams yield stable individual elements that
emboss and compress the absorbent body. Thus, areas of different
density are formed within each individual element. Density
gradients are formed along the dividing seams, optimizing fluid
transport. On the whole, the absorbent body is especially
compressed in the area around the dividing seams. The fluids such
as menstrual fluid to be absorbed by the absorbent body may consist
of various components which have different properties and are
transported to different extents through a uniformly structured
absorbent body. Due to the presence of areas of different density
and due to the density gradient prevailing along the dividing
seams, it is possible for each fluid component to find an area
especially suitable for its transport.
[0020] To further improve upon the side leakage protection, it is
especially preferable to increase the number of dividing seams in
the edge area of the absorbent body.
[0021] The segmentation of the absorbent body yields many small
individual elements that are stabilized on all sides and are
especially preferably applied to a flexible elastic substrate.
Therefore, the segments are displaceable with respect to one
another. Thus, the absorbent body can be adapted especially well to
the body contours of the wearer.
[0022] In a preferred embodiment of this invention, the absorbent
body has at least two layers, with at least one of the layers being
segmented. This permits an optimum combination of the properties of
the segmented layer with those of an unsegmented layer, for
example.
[0023] Preferred shapes for the segments created by the dividing
seams in the absorbent body may be squares and/or diamonds and/or
circles as well as any other suitable geometric shape. In another
especially preferred embodiment of this invention, the absorbent
body is designed with at least two layers, where at least one layer
of the absorbent body facing the wearer's body is smaller than at
least one other layer of the absorbent body facing away from the
wearer's body.
[0024] The layer of the absorbent body facing the wearer's body
faces the wearer's body when the absorbent article is in use and is
thus arranged over the layer of the absorbent body facing away from
the wearer's body. The latter faces away from the wearer's body
when the absorbent article is in use.
[0025] Providing an absorbent body which is designed with at least
two layers yields various functions as follows, where at least one
layer facing the wearer's body and at least one layer facing away
from the wearer's body are formed, and at least one layer of the
absorbent body facing the wearer's body is smaller than at least
one other layer of the absorbent body facing away from the wearer's
body, so that the entire absorbent material has a predetermined
"intended breaking line": [0026] providing an "intended breaking
line" as defined above yields optimum suppleness and individual
adaptation to the wearer's body, [0027] providing the two-layer
absorbent body where the layer of the absorbent body facing the
wearer's body is smaller than the layer of the absorbent body
facing away from the wearer's body creates a liquid storage area in
the center of the napkin to improve the side leakage protection,
[0028] preferably the minimum of one layer of the absorbent body
facing the wearer's body has less than 70% of the area of the
minimum of one layer of the absorbent body facing away from the
wearer's body; even more preferably, the minimum of one layer of
the absorbent body facing the wearer's body has less than 50% of
the area of the minimum of one layer of the absorbent body facing
away from the wearer's body; even more preferably, the minimum of
one layer of the absorbent body facing the wearer's body has less
than 30% of the area of the minimum of one layer of the absorbent
body facing away from the wearer's body.
[0029] The minimum of one layer of the absorbent body facing the
wearer's body is formed by the shaping methods known in the state
of the art. It is especially preferable for the minimum of one
layer of the absorbent body facing the wearer's body to be punched
out or cut out.
[0030] The term "layer" as used in the present invention includes
layers of one or more materials as well as multilayer composites
such as laminates.
[0031] In an especially preferred embodiment of the present
invention, one or more layers arranged beneath and/or above the
minimum of one layer of the absorbent body facing the wearer's body
has been processed for separation and thus segmented along the same
contours as the minimum of one layer of the absorbent body facing
the wearer's body.
[0032] The shaping of the minimum of one layer facing the wearer's
body can be performed here by one of the methods known in the state
of the art, such as cutting off or out, molding, punching, etc. The
layer of the absorbent body facing away from the wearer's body as
well as the layers of the absorbent body above and/or below that
are processed for separation, e.g., cut or punched.
[0033] In another especially preferred embodiment of the present
invention, the minimum of one layer of the absorbent body facing
the wearer's body and one or more of the layers arranged above
and/or below that are processed for separation along the same
contours as the minimum of one layer of the absorbent body facing
the wearer's body.
[0034] According to an especially preferred embodiment of the
present invention, not only the minimum of one layer of the
absorbent body facing the wearer's body is punched out or cut out,
but also additional layers which may be present in the napkin are
also punched or cut out.
[0035] Apart from the minimum of one layer of the absorbent body
facing the wearer's body, it is especially preferable for the
layers of the absorbent body facing away from the wearer's body
beneath that to be processed for separation. However, then
preferably the "frame grid" of the minimum of one layer of the
absorbent body facing the wearer's body remains in the napkin,
while the "punched grid" of the minimum of one layer of the
absorbent body facing the wearer's body is removed in any case. The
term "frame grid" as used here is understood to refer to the part
of a layer of material located outside a dividing seam provided in
it, e.g., a punched or cut area, and forming a part of the
absorbent article. In other words, the minimum of one layer of the
absorbent body facing away from the wearer's body is segmented by
separation processing into a frame grid and an area enclosed by the
frame grid. The term "punched grid" here is understood to refer to
the part of a layer of material located outside the dividing seam,
e.g., the punched or cut area, and not forming part of the
absorbent article. The "frame grid" of course has a preferred shape
for the absorbent article, which in the present case preferably
corresponds to the overall shape of the absorbent article. This
yields the absorbent body according to this invention, comprising
at least one layer facing the wearer's body which is smaller, due
to removal of the "punched grid", than the minimum of one layer
arranged at a distance from the body, likewise processed for
separation, e.g., cut or punched, and where the "frame grid" forms
a part of the absorbent article, however.
[0036] By providing an absorbent body having at least two layers,
where the minimum of one layer of the absorbent body facing the
wearer's body has a smaller area than the minimum of one layer of
the absorbent body facing away from the wearer's body, and due to
the fact that the layer of the absorbent body facing away from the
wearer's body has been punched and/or cut in a manner corresponding
to the punched or cut out area of the layer of the absorbent body
facing the wearer's body, this provides an absorbent article which
eliminates the stiffness of a continuous web of material due to the
cutouts and/or punched areas, in addition to an optimum suppleness
and an individual adaptation to the wearer's body and an
improvement in side leakage. It is known that the preferred
absorbent material used in absorbent articles has a certain
stiffness. If an entire web of material of such an absorbent
material is provided in an absorbent article, as is usually
necessary to guarantee adequate absorption and storage properties
of the absorbent article, this leads to a stiffness of the
absorbent material which makes the absorbent article uncomfortable
to wear on the whole.
[0037] This leads to a suboptimal suppleness, and adaptation to the
individual wearer's body is not guaranteed. The stiffness of a
continuous web of material can be eliminated in an inventive manner
by the cutout/punched out areas in the minimum of one layer of the
absorbent body facing away from the wearer's body. This leads to a
great improvement in suppleness and the possibility of an
individual adaptation to the body of the wearer.
[0038] Furthermore, the permeable areas of the cutout or punched
out areas facilitate more rapid penetration of the secreted fluid
deeper into the napkin and thus prevent side leakage in an improved
manner and thus prevent soiling of the wearer's body or the
adjacent clothing in the area of the absorbent article and thus
contribute toward a reduction in surface moisture. This effect is
increased by the altered capillarity of the materials in the
immediate vicinity of the punched out/cutout areas. The material is
compressed there', thus increasing the capillarity. This causes a
more effective fluid transport into these areas which thus function
as "intended penetration areas" where the fluid is transported
especially rapidly and effectively.
[0039] Preferably the minimum of one layer of the absorbent body
facing the wearer's body, which is smaller than the minimum of one
layer of the absorbent body facing away from the wearer's body, is
in the shape of an oval. Other possible shapes include a
rectangular shape, a tongue shape, a triangular shape, a circular
shape, a trapezoidal shape or an hourglass shape. Any other
geometric shape is also conceivable for the present invention, as
long as it meets the requirements specified above.
[0040] In another preferred embodiment of this invention,
additional dividing seams, e.g., cut-out or punched-out areas, are
provided in the minimum of one layer of the absorbent body facing
the wearer's body and/or within one or more layers of the absorbent
body arranged above and/or below that. These additional dividing
seams, e.g., cut-out or punched-out areas, are arranged inside the
areas of the above-mentioned layers determined by the shape of the
minimum of one layer of the absorbent body facing the wearer's
body. For example, the minimum of one layer of the absorbent body
facing the wearer's body may have an oval shape and may have
additional oval cut-out or punched-out areas concentric with the
former. The additional layers of the absorbent body may also have
these additional oval punched out areas arranged concentrically,
where the corresponding punched areas in the different layers
essentially coincide.
[0041] The additional dividing seams, e.g., cut-out or punched-out
areas in the various layers of the absorbent body, improve the
suppleness and adaptability to the body of the individual wearer
through the resulting segmentation, while also improving the fluid
transport within the absorbent article.
[0042] Preferably the absorbent article according to the present
invention comprises the following components: [0043] a) a
liquid-permeable cover layer and [0044] b) a liquid-impermeable
backing layer, where the absorbent body is arranged between the
cover layer and the backing layer.
[0045] The minimum of one layer of the absorbent body facing away
from the wearer's body preferably has elongated side areas. The
cover layer and/or the backing layer may extend laterally outward
from the elongated side parts of the absorbent body to provide a
pair of elongated side edges for the absorbent article. The cover
layer is arranged on the side facing the wearer's body and should
be arranged next to the wearer during use. The backing layer is
arranged parallel to the cover layer and should be next to the
wearer's underwear garment when being used.
[0046] The cover layer may be manufactured from materials known in
the state of the art. They should be liquid permeable. Known
materials include, for example, card weaves and spunbonded
nonwovens made of polyester, polypropylenes, polyethylene, nylon or
other heat-bonded fibers. Other polyolefins such as copolymers of
polypropylene and polyethylene, linear, low-density polyethylene
fiber nonwovens which are finely perforated or mesh-like materials
are also suitable. Other suitable materials include composite
materials of polymers and a nonwoven material. The composite layers
are usually formed by extrusion of a polymer on a layer of a
spunbonded nonwoven to form an integral layer. This material is
preferred, because the outer surface is not irritating to the skin
of the wearer and it has a pleasant feel.
[0047] With regard to the above-mentioned cover layer, it is also
advantageous that this cover layer has the following features. In
general, a cover layer is provided to achieve the greatest possible
comfort and great adaptability to the wearer's body and should
divert fluid to the body under it. The cover layer may be
constructed of a relatively nonabsorbent liquid-permeable material,
where the cover layer may be constructed of any woven or nonwoven
material through which body fluid which contacts its surface can
flow easily. The cover layer is preferably made of a material that
permits the passage of fluid without drawing the fluid horizontally
in parallel to the cover layer to any great extent. In addition,
the cover layer should retain little or no fluid in its structure,
so that a relatively dry surface is provided next to the wearer's
skin. In general, the cover layer is a single layer of a material
with a width sufficient to cover the surface of the absorbent body
facing the wearer's body. The cover layer preferably extends to the
longitudinal edges and is bonded to the backing layer. The cover
layer may be bonded to the backing layer using any known method
which does not leave any hard or uncomfortable residues that would
annoy the wearer. Those skilled in the art are familiar with
methods of bonding the various materials and for bonding other
possible materials in the absorbent article according to the
present invention, including the use of pressure-sensitive
adhesives, hot-melt adhesives, two-sided adhesive sheets,
ultrasonic welding and heat sealing, to name but a few. Adhesives
such as hot-melt adhesives may be used uniformly or in the form of
a continuous or noncontinuous layer.
[0048] The cover layer may be designed in two parts. Two parts here
means that the cover layer may consist of an outer area and a
central area. The outer area is preferably essentially in the area
of the longitudinal edges of the absorbent article and, if there
are wings on the napkin, it may also be designed in the area of the
wings, where the central area is designed in the remaining central
area of the absorbent article. The two parts of the cover layer can
be bonded together. Such a bond can be produced by using a hot-melt
adhesive or by providing a welded seam. Other forms of bonds that
are known in this field of the art are also included here.
[0049] If the cover layer is designed in two parts, the central
area of the cover layer and/or the outer area of the cover layer
may be a spunbonded nonwoven of polypropylene having an especially
thick fiber and thus a high denier. Furthermore, this spunbonded
nonwoven may contain more pigment, e.g., have a higher titanium
dioxide content to improve the masking properties. Such a
polypropylene spunbonded nonwoven with the properties described
above may have, for example, a basis weight of 15 to 50 g/m.sup.2
preferably 20 g/m.sup.2. In a preferred embodiment, it is 70 mm
wide.
[0050] Other possible materials for the outer area of the cover
layer and/or the inner area of the cover layer include spunbonded
nonwovens or carded nonwovens of polypropylene, for example, with a
basis weight of 15 to 50 g/m.sup.2, preferably 20 g/m.sup.2. The
preferred composition of the cover layer is a two-part cover layer,
where the outer area of the cover layer is made of a polypropylene
spunbonded nonwoven with a basis weight of 20 g/m.sup.2, and where
the inner area of the cover layer is made of a perforated
polypropylene spunbonded nonwoven in a weight of 20 g/m.sup.2. The
two parts of the cover layer are preferably bonded by a welded
seam.
[0051] The backing layer may be made of any desired material that
is liquid-impermeable. The backing layer preferably allows
atmospheric vapor and moisture to pass through the absorbent
article while preventing body fluid from passing through. A
suitable material is a microembossed polymer film such as
polyethylene or polypropylene with an approximate thickness of
0.025 to 0.13 mm. Two-component films may also be used, as well as
nonwoven materials or woven materials which are treated to make
them liquid impermeable. Other suitable materials include films
filled with CaCO.sub.3 or polyolefin in foams. A polyethylene foam
with a thickness in the range of approximately 0.5 mm to
approximately 10 mm can be mentioned as an example.
[0052] The absorbent body in the absorbent article provides a means
for absorbing the secreted fluid, in particular menstrual fluid.
The total absorption capacity of the absorbent body should
correspond to the anticipated loading in the course of the intended
use of the absorbent article. In addition, the size and shape of
the absorbent body may vary. As explained above, the absorbent body
may have the various shapes mentioned above in the area of the
minimum of one layer of the absorbent body facing the wearer's
body. The minimum of one layer of the absorbent body facing away
from the wearer's body may also have various shapes, but at any
rate it should be larger than the minimum of one layer facing the
wearer's body. It can function as a secondary reservoir. The layer
of the absorbent body facing away from the wearer's body may be,
for example, rectangular with rounded longitudinal edges,
tongue-shaped or oval or it may have any other known geometric
shape known in the related art.
[0053] The absorbent body is generally made of one or more
materials which together are essentially hydrophilic, compressible,
adaptable and non-irritating for the skin of the wearer. Suitable
materials are well known in the field and include, for example,
various natural or synthetic fibers, cellulose fibers, regenerated
cellulose or cotton fibers or a blend of cellulose and other
fibers, melt-blown polymers such as polyester and polypropylene.
The absorbent layers may also include other well-known materials
which are used with absorbent articles, including several layers of
a cellulose filling, rayon fibers, cellulose sponge, hydrophilic
synthetic sponges, such as polyurethane and the like.
[0054] In addition, especially when used in incontinence articles,
the absorbent body may contain superabsorbers which are very
effective in retaining body fluids. Superabsorbers have the ability
to absorb a large amount of fluid in relation to their own weight.
Typical superabsorbers used in absorbent articles such as sanitary
napkins can absorb between approximately 5 and 60 times their
weight in body fluids.
[0055] A preferred material for the absorbent layer is a coform
material which contains, for example, cellulose and polypropylene
in a weight ratio of 70:30 and has a basis weight of 150 g/m.sup.2
and is used together with a polypropylene spunbonded nonwoven
backing with a basis weight of 17 g/m.sup.2. As an alternative, for
example, a coform material containing cellulose and polypropylene
in a weight ratio of 60:40 and having a basis weight of 90
g/m.sup.2 may also be used together with a polypropylene spunbonded
nonwoven backing with a basis weight of 20 g/m.sup.2.
[0056] Another layer may be provided on the side of the absorbent
body facing the wearer's body, acting as the transfer layer and
transfers the fluid to the absorbent body in a suitable manner.
This transfer layer is preferably punched or cut out in the same
way as the minimum of one part of the absorbent body facing the
wearer's body. This transfer layer especially preferably has an
open structure which is especially permeable for fluids and has
large pores but a low density. For example, laminates of spunbonded
nonwoven and carded nonwovens are suitable, with the fluffy side
facing up. Such a transfer layer may also have a laminating
function (dry and clean).
[0057] The transfer layer and/or the minimum of one layer of the
absorbent body facing the wearer's body can be differentiated
visually from the rest of the sanitary napkin, for example by using
a different color for the transfer layer and/or the minimum of one
layer of the absorbent body facing the wearer's body than for the
rest of the absorbent article.
[0058] The transfer layer and/or the minimum of one layer of the
absorbent body facing the wearer's body are preferably punched or
cut out and applied to one or more other absorbent layer(s) of the
absorbent body, preferably made of coform, and preferably bonded
together by one of the possible methods mentioned above.
[0059] Although the transfer layer and/or the upper layer of the
minimum of one layer of the absorbent body facing the wearer's body
may have a laminating function, this laminating function may also
be assumed, instead or in addition, by the cover layer. The cover
layer may in this case contain approximately 1% to 6% titanium
dioxide pigment and may have a clean and attractive appearance.
[0060] In another preferred embodiment of this invention, the
liquid-permeable cover layer may also have a plurality of openings
which are formed in it. The size of these openings should be such
that a fluid can pass through the cover layer and thereby enter the
absorbent body. The openings may be arranged in a longitudinal
direction or may be localized in larger numbers in a certain area,
which is assumed to be the area that will come in contact with the
fluid. The openings should increase the rate at which the body
fluids can reach the absorbent body. This facilitates providing a
much drier surface for the cover layer than if the openings were
not present.
[0061] The part of the absorbent body facing the wearer's body may
preferably have embossed lines through which the fluid is guided
along especially preferred pathways. These embossed lines may also
be provided in the transfer layer and/or individual or all of the
other layers of the absorbent body.
[0062] The cover layer may also be treated with a surfactant to
make it more hydrophilic and thus support the absorption of fluid.
The surfactant may contain topical additives or internally added
materials such as polysiloxanes.
[0063] Furthermore, the absorbent article may have another layer on
the side of the absorbent body facing away from the wearer's body
to act as a distributing layer. In a preferred embodiment, this
distributing layer is folded. It may serve as the primary
reservoir. It advantageously contains especially small pores and
thus has the greatest capillarity in the system of the preferred
absorbent article according to the present invention. A melt-blown
fiber layer is especially preferably used for the distributing
layer. This melt-blown layer of polypropylene, for example, may
have a basis weight of 65 g/m.sup.2 and in a preferred embodiment
it is folded to a final width of 45 mm and a length of 125 mm.
[0064] Some or all of the individual layers of the absorbent
article may be bonded together in some areas or in totality. In a
preferred embodiment, their bonding can be accomplished by using a
hot-melt adhesive. Other bonding methods known in the related art,
however, should also be included within the scope of the present
patent application.
[0065] In another preferred embodiment of this invention, the
absorbent article according to the present invention has wings on
its longitudinal side edges, where the minimum of one layer of the
absorbent body facing away from the wearer's body may continue into
these wings but need not necessarily extend into these wings. The
wings and the longitudinal body of the absorbent article may be
provided with a longitudinal adhesive system consisting of a
hot-melt adhesive, for example, with a preferred area of
50.times.190 mm for the longitudinal body of the absorbent article
and a preferred area of 20.times.50 mm for the respective wing
adhesive systems of the absorbent article. The longitudinal
adhesive system and the wing adhesive systems are each preferably
covered by silicone paper or some other possible covering which is
known in the state of the art.
[0066] The absorbent article according to the present invention is
preferably used as a sanitary napkin or as an incontinence
diaper.
[0067] Furthermore, the absorbent body according to the present
invention may include a flow layer and a reservoir layer in a
manner familiar to those skilled in the art. Suitable flow layers
are made, for example, of cellulose, cellulose-synthetic fiber
blends such as coform materials, airlaid-cellulose-synthetic fiber
blends, foam materials or high-loft nonwovens and they may contain
superabsorbers as an additional component.
[0068] Suitable reservoir layers are characterized, for example, by
the materials mentioned above for the absorbent body. In an
especially preferred embodiment, the minimum of one layer of the
absorbent body facing the wearer's body acts as a flow layer.
[0069] The absorbent article according to the present invention
especially preferably has a density and/or pore gradient. The layer
next to the body has the lowest density and the layer next to the
liquid-impermeable backing layer has the greatest density.
[0070] This facilitates diversion of fluid away from the wearer's
body.
[0071] Such a density and/or pore gradient can be produced in a
manner known to those skilled in the art, e.g., by using materials
of different densities or by using different pore sizes, etc.
[0072] In another aspect, the present invention provides a method
of producing an absorbent body, in particular a segmented absorbent
body. These absorbent bodies are used in particular in the
absorbent articles according to this invention.
[0073] A first method according to this invention includes the
following steps: a first web of material is brought over a first
rotating conveyor element; the first web of material is processed
for separation by a second rotating conveyor element along a closed
line, creating a first closed dividing seam through the entire
thickness of the first web of material; the part of the first web
of material outside the first dividing seam is conveyed away over
the first rotating conveyor element; the minimum of one part of the
first web of material bordered by the first dividing seam is
conveyed further with the second rotating conveyor element; a
second web of material is conveyed over a third rotating conveyor
element; the minimum of one part of the first web of material
bordered by the first dividing seam is deposited on the second web
of material, and the second web of material is processed for
separation by the second rotating conveyor element along the
peripheral shape of the minimum of one part of the first web of
material bordered by the first dividing seam, thereby creating a
minimum of one second self-contained dividing seam through at least
partial areas of the thickness of the second web of material, and
the minimum of one first and second self-contained dividing seam
essentially coincide.
[0074] The first web of material and the second web of material may
comprise individual materials or multiple materials.
[0075] The first web of material and the second web of material may
each be composed of one or more layers which may preferably be
bonded together with adhesive and which may consist of different
materials. The first web of material may comprise in particular
layers of the materials used in the minimum of one layer of the
absorbent body facing the wearer's body as well as the transfer
layer of the absorbent article according to this invention.
[0076] The second web of material may comprise in particular layers
of the materials used in the minimum of one layer of the absorbent
body facing away from the wearer's body and the distributing layer
of the absorbent article according to this invention.
[0077] The term "self-contained dividing seam" as used in the
present invention is understood to refer to dividing seams which
define an internal closed geometric shape in a web of material.
[0078] The minimum first and second self-contained dividing seams
may assume any suitable geometric shape, but the especially
preferred shapes are an oval, a triangle, a circle, a tongue or an
hourglass. The shape of the layer of the absorbent body facing the
wearer's body in the finished absorbent article according to this
invention is determined by the shape of the first dividing
seam.
[0079] In an especially preferred embodiment of the method
according to this invention, the second web of material and the
minimum of one part deposited on the former and bordered by the
first dividing seam is separated into individual units in another
step, with each unit comprising a part of the first web of material
bordered by the first dividing seam and a frame grid formed by the
second web of material.
[0080] The term "frame grid" as used here, by analogy with the
articles according to this invention described here, is understood
to be the part of the material of the absorbent material which
remains outside the second dividing seam. The frame grid thus
corresponds, for example, to the part of the layer of the absorbent
article according to this invention facing away from the wearer's
body outside the second dividing seam. The frame grid includes the
area of the second web of material defined by the second dividing
seam.
[0081] In another preferred embodiment of the two methods according
to this invention as described here, the individual steps of the
method are repeated continuously.
[0082] In an especially preferred embodiment of the method
according to the present invention, the first web of material is
conveyed at a rate corresponding to the peripheral speed of the
second conveyor element. This embodiment of the method can be used
in particular with the absorbent articles produced according to
this invention, when the difference in length between the part of
the web of material bordered by the first line, corresponding to
the layer of the absorbent body facing the wearer's body and the
frame grid formed by the second web of material or the layer of the
absorbent body facing away from the wearer's body is not very
great, e.g., amounting to less than 25%.
[0083] One embodiment of the method according to this invention in
which the first web of material is conveyed intermittently and the
second rotating conveyor element rotates continuously is especially
preferred.
[0084] This has the advantage that the cost of materials can be
minimized. Due to the intermittent conveyance of the first web of
material over the first rotating conveyor element with a second
conveyor element rotating continuously at the same time, the first
self-contained dividing seams can be worked into the first web of
material in a closer sequence in successive separation processing
steps than if the first and second conveyor elements were running
continuously in synchronization. Therefore, the amount of the first
web of material used for the absorbent article can be increased,
and the amount of the first web of material discarded and thus the
amount of waste can be minimized.
[0085] This process management is especially preferred if the
difference in length between the layer facing the wearer's body and
the layer facing away from the wearer's body is relatively great in
the absorbent article produced, e.g., greater than 25%. In these
cases, due to the more effective utilization of the first web of
material, the method can be less expensive. Intermittent conveyance
is understood here to refer to both conveyance at two different
successive speeds and interrupted conveyance in phases.
[0086] In a most especially preferred embodiment of the method
according to this invention, the first and second rotating conveyor
elements run in synchronization during the separation working of
the first web of material. This has the advantage that the shape of
the minimum of one part of the first web of material bordered by
the first dividing seam corresponds exactly to the shape of the
second dividing seam in the second web of material, when the same
dividing elements are used for the two separation processing
steps.
[0087] In another especially preferred embodiment of the method
according to this invention, the rotating conveyor elements are
designed in the form of rolls or wheels. These designs permit an
especially simple and inexpensive embodiment of this method.
[0088] In another especially preferred embodiment of the method
according to this invention, the first web of material is processed
for separation by means of at least one separating element mounted
on the second rotating conveyor element.
[0089] It is also especially preferred for the second web of
material to be processed for separation by means of at least one
separating element mounted on the second rotating conveyor
element.
[0090] This makes it possible to mount similar separating elements
on the second rotating conveyor element, which is especially
economical.
[0091] The separating element may be, for example, all known
cutting or punching devices with which those skilled in the art are
familiar. They may be mounted on the second conveyor element in a
fixed mount or so they can be telescoped outward.
[0092] Due to the fact that the minimum of one part of the first
web of material bordered by the first dividing seam is deposited on
the second web of material by means of the second conveyor element,
this yields a composite web of material in which a particular
structure is preformed. In subsequent separation of the composite
web of material into separate individual units, these units each
include a top layer and a bottom layer, with the top layer having a
smaller surface area than the bottom layer, and the bottom layer
having a dividing seam corresponding to the shape of the top
layer.
[0093] In another especially preferred embodiment of the method
according to this invention, in another step, the second web of
material and the minimum of one part of the first web of material,
bordered by the first dividing seam and deposited on the second
web, are divided into individual units, with each unit comprising a
part of the first web of material bordered by the first dividing
seam plus a frame grid formed by the second web of material.
[0094] In an especially preferred embodiment of the method
according to this invention, an adhesive layer is applied at least
to partial areas of the second web of material in order to bond the
second web of material adhesively to at least parts of the first
web of material. It is especially preferable to provide an adhesive
layer only on those areas of the second web of material where the
minimum of one part of the first web of material bordered by the
first dividing seam has been deposited.
[0095] In an especially preferred embodiment of the method
according to this invention, a reduced pressure is created in an
area of the second conveyor element to support the conveyance of
the minimum of one part of the first web of material bordered by
the first dividing seam on the second conveyor element.
[0096] It is advantageous here to design the second conveyor
element as a hollow wheel or roller, where the conveyor element
designed to be hollow is preferably subdivided into angular
segments by at least one inner bulkhead, and these angular segments
may be acted upon by pressure independently of one another in the
form of a reduced pressure reservoir, a balanced pressure reservoir
or an excess pressure reservoir. The segment of the conveyor
element with which the web of material is conveyed is preferably
acted upon by reduced pressure.
[0097] As an alternative, however, other methods known to those
skilled in the art may also be used to support or accomplish the
adhesion of the web of material to the second conveyor element and,
thus, conveyance of the web of material.
[0098] In addition, in another especially preferred embodiment of
the method according to this invention, deposition of the part of
the first web of material bordered by the first dividing seam onto
the second web of material can be accomplished or supported by an
excess pressure produced in the area of the second conveyor
element.
[0099] Deposition of the part of the first web of material bordered
by the first dividing seam on the second web of material is
supported or accomplished by applying an excess pressure to a
suitable angular segment of the conveyor element.
[0100] As an alternative, deposition of the part of the first web
of material bordered by the first dividing seam onto the second web
of material can be supported or accomplished by an elastic
ejector.
[0101] In another especially preferred embodiment of the method
according to this invention described here, several first and
second self-contained dividing seams are worked side-by-side into
the first and/or second webs of material in spaced apart
relationship. This has the advantage that wider webs of material
can be used and thus, higher piece numbers of the absorbent
articles can be produced per unit of time.
[0102] Although the minimum of one first dividing seam always
extends throughout the entire thickness of the first web of
material, and thus the forms described above are separated from the
first web of material, the second dividing seam can extend
throughout the entire thickness of the second web of material, or
only through partial areas of the thickness of the second web of
material. Thus, in the latter case, an intended breaking line is
created in the material of the second web of material.
[0103] In the absorbent article produced by the method according to
this invention, the shape of the layer of the absorbent body facing
the wearer's body is determined by the minimum of one first
dividing seam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0104] The present invention will now be described in detail with
the help of the accompanying figures, where:
[0105] FIG. 1 is a top view of a preferred embodiment of the
present invention;
[0106] FIG. 2 is cross section through a preferred embodiment of
the present invention;
[0107] FIG. 3 is a perspective view of a preferred embodiment of
the present invention in a partially cutaway view;
[0108] FIGS. 4 through 7 are preferred segmentations in an
absorbent body which can be used in preferred embodiments of the
present invention;
[0109] FIG. 8 is a device for carrying out the method of producing
an absorbent article;
[0110] FIG. 9 is another device for carrying out the method of
producing an absorbent article; and
[0111] FIGS. 10 a through k are especially preferred shapes and
punched patterns of the layer of the absorbent body facing the
wearer's body.
[0112] The reference numbers used in the figures have the following
meanings: [0113] 1: outer cover layer [0114] 2: hot-melt adhesive
[0115] 3: central cover layer [0116] 4: transfer layer [0117] 5:
layer of the absorbent body facing the wearer's body [0118] 6:
layer of the absorbent body facing away from the wearer's body
[0119] 7: distributing layer [0120] 8: backing layer [0121] 9: wing
adhesive system [0122] 10: covering of the wing adhesive system
[0123] 11: longitudinal body adhesive system [0124] 12: covering of
the longitudinal body adhesive system [0125] 13: welded seam [0126]
14: wing [0127] 15: dividing seam [0128] 20: first conveyor element
[0129] 21: second conveyor element [0130] 22: separating element
[0131] 24: third conveyor element [0132] 25: first web of material
[0133] 26: second web of material [0134] 28: first self-contained
dividing seam [0135] 29: second self-contained dividing seam [0136]
30: part of the web of material bordered by the first dividing seam
[0137] 31: part of the first web of material outside the first
dividing seam [0138] 33: loop forming roller [0139] 35: loop
forming roller [0140] 36: tension rollers [0141] 37: tension
rollers [0142] 38: d.c. motor [0143] 39: reduced pressure area
[0144] 40: screen [0145] 41: excess pressure area [0146] 42:
adhesive device [0147] 43: adhesive layer [0148] 45: width
adjusting roller [0149] 46: draw-off roller [0150] 47: web width
[0151] 48: composite web [0152] 50: absorbent body
DETAILED DESCRIPTION OF THE DRAWINGS
[0153] The sanitary napkin illustrated in FIGS. 1 and 2 has
essentially an hourglass shape with wings 14 that project outwards
being formed in the middle of the longitudinal sides and which are
tapered toward the middle. The length of the sanitary napkin may be
238 mm, for example, and the width including the two wings 14 is
150 mm, for example. The top layer of the sanitary napkin is formed
by an outer cover layer 1 and a central cover layer 3. The central
cover layer 3 extends along a central strip over the entire length
of the sanitary napkin. The width of the central cover layer 3 may
be 70 mm, for example. The central cover layer is made of a
perforated polypropylene spunbonded nonwoven with a basis weight of
20 g/m.sup.2.
[0154] The outer cover layer 1 overlaps with the central cover
layer 3 and is bonded to it in the overlap area. This bonding can
be accomplished by a welded seam, for example. As an alternative,
the two cover layers 1 and 3 may also be bonded together by a
hot-melt adhesive. The outer cover layer is also made of a
perforated polypropylene spunbonded nonwoven with a basis weight of
20 g/m.sup.2.
[0155] The multi-layer absorbent body of the sanitary napkin is
located beneath the central cover layer. In the advantageous
embodiment of this invention described here, the absorbent body
includes as the top layer the transfer layer 4. The layer of the
absorbent body 5 facing the wearer's body is beneath the transfer
layer 4 and may also be referred to as an absorbent core. The layer
of the absorbent body 6 facing away from the wearer's body is also
arranged beneath the layer 5 with the distributing layer 7 arranged
beneath it.
[0156] The transfer layer 4 is bonded to the central cover layer 3
over its upper surface by means of a hot-melt adhesive 2. The
transfer layer 4 consists of a laminate of a spunbonded nonwoven
and a carded nonwoven with a basis weight of 52 g/m.sup.2 and is
arranged in such a manner that the fluffy side of the laminate
faces upward, i.e., in the direction of the wearer's body. In
addition, the transfer layer is differentiated in color from the
remainder of the sanitary napkin.
[0157] The layer of the absorbent body 5 facing the wearer's body
is arranged beneath the transfer layer 4. The transfer layer 4 and
the layer of the absorbent body 5 facing the wearer's body are
bonded together by means of a hot-melt adhesive 2. The transfer
layer 4 and the layer of the absorbent body 5 facing the wearer's
body are punched out in the form of an oval in the present
advantageous embodiment of this invention, and they are arranged in
the central area of the sanitary napkin. The oval shape has a
length of 110 mm, for example, and a width of 45 mm. The layer of
the absorbent body 5 facing the wearer's body is made of a coform
material, for example, containing cellulose and polypropylene in a
weight ratio of 70:30 and having a basis weight of 150 g/m.sup.2.
It is used together with a spun-bonded nonwoven carrier of
polypropylene with a basis weight of 17 g/m.sup.2. The laminate of
coform material and spunbonded nonwoven carrier has a line
embossing with compressed areas.
[0158] Especially preferred shapes of layer 5 facing the wearer's
body which may be used as an alternative to the oval shape are
illustrated in FIGS. 10a-k. In addition, the layers 5 of the
absorbent body facing the wearer's body, as shown in FIGS. 10a-k,
have internal dividing seams 15 which further segment the layers 5.
These dividing seams also may be provided in the same way in layers
4, 6, 7 of the absorbent body above and/or beneath that.
[0159] The layer of the absorbent body 6 facing away from the
wearer's body is arranged beneath the layer of the absorbent body 5
facing the wearer's body. The layer of the absorbent body 6 extends
essentially over the same area as the central cover layer 3, but is
shorter in the area of the rounded transverse ends of the sanitary
napkin, so that the central cover layer 3 projects over the layer
of the absorbent body 6 facing away from the wearer's body in this
area. The layer of the absorbent body 6 facing away from the
wearer's body may be 220 mm long and 70 mm wide, for example, and
made of a coform material of cellulose and polypropylene in a
weight ratio of 60:40 and with a basis weight of 90 g/m.sup.2. It
is used together with a spunbonded nonwoven carrier of
polypropylene with a basis weight of 20 g/m.sup.2.
[0160] An oval punched area provided in the central area of the
layer of the absorbent body 6 facing away from the wearer's body
corresponds in size and shape to the layer of the absorbent body 5
facing the wearer's body and to the transfer layer 4. Due to the
punched area, the layer of the absorbent body 6 facing away from
the wearer's body is divided into an inner area and an outer area.
The outer area represents the frame grid. The inner oval area of
the layer of the absorbent body 6 facing away from the wearer's
body lies with complete coverage beneath the layer of the absorbent
body 5 facing the wearer's body. The top surface of the layer of
the absorbent body 6 facing away from the wearer's body is bonded
to the central cover layer 3 by means of a hot-melt adhesive 2 in
the area not covered by the layer of the absorbent body 5 facing
the wearer's body.
[0161] In the central area of the sanitary napkin, the distributing
layer 7 is arranged beneath the layer of the absorbent body 6
facing away from the wearer's body. The distributing layer 7 is
made of a web of embossed melt-blown material of polypropylene with
a basis weight of 65 g/m.sup.2 folded on itself to yield a final
width of 45 mm with a length of 125 mm, for example. A
liquid-impermeable backing layer 8 arranged beneath the
distributing layer 7 is made of a polyethylene film with a basis
weight of 25 g/m.sup.2. The liquid-impermeable backing layer
prevents the fluid that has penetrated into the sanitary napkin and
been retained there from escaping outward from the absorbent layers
at the bottom. The backing layer 8 is bonded to the layer of the
absorbent body 6 facing away from the wearer's body and to the
central cover layer 3 and the outer cover layer 1 by means of a
hot-melt adhesive 2.
[0162] In the area of the wings 14, wing adhesion systems 9 are
provided on the outer surface of the backing layer 8 facing away
from the wearer's body; by means of these wing adhesion systems,
the wings 14 can be attached to the side of the wearer's underwear
facing away from the wearer's body. The adhesive material may be,
for example, a hot-melt adhesive. To protect the adhesive surfaces
of the wing adhesion systems 9, they are provided with a covering
10 of silicone paper which can be removed from the adhesive
elements before using the sanitary napkin. Before use, the two
wings 14 and the side areas of the sanitary napkin can be folded
onto the central cover layer 3, so that the wing adhesion systems 9
come to lie side by side. The two wing adhesion systems 9 may then
be covered with the covering 10 of silicone paper which may have an
area of 70 mm.times.60 mm, for example.
[0163] Additional fixation of the sanitary napkin to the wearer's
underwear is made possible by the longitudinal body adhesive system
11 which extends over the central area of the outer surface of the
backing layer 8 over an area of 50 mm.times.190 mm. The sanitary
napkin can be attached to the inside of the wearer's underwear with
the longitudinal body adhesive system 11. The longitudinal body
adhesive system 11 may also be formed by a hot-melt adhesive, for
example, and is protected by a second covering 12 which is
detachably attached to it. The covering 12 of the longitudinal body
adhesive system is also made of silicone paper and has an area of
60 mm.times.200 mm. The covering 12 is removed before using the
sanitary napkin, thus exposing the adhesive surface of the
longitudinal body adhesive system 11.
[0164] FIGS. 4 through 7 illustrate various segmentation patterns
which can be provided in the absorbent body 50 or individual layers
of the absorbent body 50 of the absorbent article. FIG. 4
illustrates a square segmentation and FIG. 5 illustrates rhomboidal
segmentation. FIG. 6 shows the segmentation in the form of a
plurality of circular dividing seams 15.
[0165] When using an oval-shaped minimum of one layer 5 of the
absorbent body facing the wearer's body, the segmentation
illustrated in FIG. 7 of at least one of the layers 4, 6, 7 of the
absorbent body 50 arranged above and/or beneath it is especially
advantageous. Due to the dividing seams 15 extending radially
outward from the oval peripheral shape of the minimum of one layer
5 of the absorbent body facing the wearer's body (soleil notching),
an especially easy basket shaping of the absorbent article and thus
improved suppleness (body fit) to the wearer's body are
achieved.
[0166] FIG. 8 illustrates a device for carrying out the method
according to this invention.
[0167] A first running web of material 25 of absorbent material is
conveyed over a conveyor unit (not shown here), e.g., driven
conveyor rolls or belts or rollers to two loop-forming rollers 33,
35. A supply loop of the first web of material 25 is formed by the
two loop-forming rollers 33, 35.
[0168] As an alternative, instead of the loop-forming rollers 33,
35, other storage devices with which those skilled in the art are
familiar may also be used. The first web of material 25 is then
conveyed over two tension rollers 36, 37 that are synchronized but
driven intermittently to the first conveyor element 20. The first
conveyor element 20 is designed here as a counter-cutting roller.
The irregular or intermittent drive of the tension rollers 36, 37
is accomplished by an electronically controlled d.c. motor, but it
may also be provided by other means such as a corresponding
hydraulic or mechanical system. For example, it is also conceivable
to use cams or disks.
[0169] The first web of material 25 is guided between the mating
cutting roller 20 and a second conveyor element 21 which is
designed here as a cutting roller 21. The cutting roller 21 is
subdivided into segments in its interior by an internal bulkhead,
for example, thus forming an area 39 which is acted upon by a
reduced pressure and an area acted upon by an excess pressure. The
internal bulkhead here is stationary, whereas the outer shells of
the roller are rotating. Mesh-like screens 40 are applied to the
outer shell of the cutting roller 21 at regular intervals along the
circumference of the roller, so that the excess pressure or reduced
pressure can act on the respective parts of the web of material
above the screens 40. Due to the rotation of the outer shell of the
cutting roller 21 either a reduced pressure or an excess pressure
can act in the area of each screen 40. Individual separating
elements 22 are arranged around each screen 40. These separating
elements here are designed as punching devices; as an alternative,
however, cutting devices may also be used. Those skilled in the art
are familiar with suitable cutting or punching devices. Individual
areas 30 of the first web of material are punched out by the
punching devices 22 and are conveyed further on the cutting roller
21 by the reduced pressure acting through the screens 40 in the
punched area.
[0170] The parts 30 of the web of material bordered by the first
dividing seam in the method described here are oval. They are
referred to below as the absorbent core 30. The part 31 of the
first web of material outside the first dividing seam, i.e., the
punched grid, is conveyed away after punching over the mating
cutting roller 20 and a width adjusting roller 45 and draw-off
roller 46. The first web of material 25 is under continuous tension
due to the width adjusting roller 45 and the draw-off roller
46.
[0171] Due to the intermittent drive of the tension rollers 36, 37,
the first web of material 25 reaches a speed corresponding to the
peripheral speed of the cutting roller 21 only during the punching
operation. Therefore, the distance between two punched-out areas in
the punched grid, referred to here as the web width 47, can be kept
as small as possible. This is especially advantageous if the
absorbent cores 30 are deposited onto the second web of material at
a relatively great distance from one another, e.g., if this
distance exceeds the length of the absorbent cores 30 by 25%.
[0172] A third conveyor element 24 is arranged next to the cutting
roller 21 at a distance from the first mating cutting roller 20 in
the direction of production. This third conveyor element is also
designed as a second mating cutting roller 24. A second web of
material 26, also an absorbent material, is conveyed over an
unwinder (not shown) and between the cutting roller 21 and the
second mating cutting roller 24. Due to the punching devices 22
mounted on the cutting roller, punched areas are being worked into
the second web of material continuously, having essentially the
same shape and size as the punched absorbent cores 30 punched out
of the first web of material 25. The absorbent cores 30 are
deposited on the second web of material 26 simultaneously with the
punching operation. To do so, the internal segmentation of the
cutting roller is designed so that an excess pressure 41 acts on
the corresponding absorbent core 30 through the corresponding
screen 40 during the punching operation. By simultaneously
depositing the absorbent cores 30 on the second web of material and
punching the second web of material 26, the result is that the
second web of material is punched in the resulting composite web 48
along the contours of the absorbent cores 30 deposited on the
web.
[0173] Adhesion between the absorbent cores 30 and the second web
of material is supported by application of adhesive 43 by an
adhesive device 42 before punching.
[0174] An intermittent drive of the first web of material is not
necessary if the distance between two successive absorbent cores 30
exceeds its own length by only less than 25%. The elasticity of the
first web of material here makes it possible for the first web of
material to be conveyed towards and away at a lower speed than the
peripheral speed of the cutting roller 21. Therefore, it is also
possible to reduce the amount of the punched grid in the first web
of material. FIG. 9 illustrates a method in which two methods as
described above are combined in succession. In the method
illustrated here, the composite web 48 produced in the first method
is used as the second web of material in the successive method.
[0175] This makes it possible to deposit additional absorbent cores
30' punched out of a third web of material onto the composite web
48 in corresponding manner and then to segment the composite web 48
through additional punching. The absorbent cores 30' deposited on
the composite web 48 in the subsequent procedure may have the same
or different shapes and sizes as the absorbent cores 30 punched out
of the first web of material and already deposited on the composite
web.
* * * * *