U.S. patent application number 14/309322 was filed with the patent office on 2014-10-09 for method of manufacturing absorbent articles, apparatus for manufacturing absorbent articles and disposable pant.
This patent application is currently assigned to SCA Hygiene Products AB. The applicant listed for this patent is SCA Hygiene Products AB. Invention is credited to Lucas BACK, Lennart Nilsson.
Application Number | 20140303587 14/309322 |
Document ID | / |
Family ID | 42732276 |
Filed Date | 2014-10-09 |
United States Patent
Application |
20140303587 |
Kind Code |
A1 |
BACK; Lucas ; et
al. |
October 9, 2014 |
METHOD OF MANUFACTURING ABSORBENT ARTICLES, APPARATUS FOR
MANUFACTURING ABSORBENT ARTICLES AND DISPOSABLE PANT
Abstract
A method of manufacturing absorbent articles includes feeding a
longitudinal web of web material having openings such that spaced
apart, opposing margins of web material are formed between the
respective opening and opposing longitudinal edges of the web
material; carrying out a folding action of folding the web about
itself along its longitudinal direction; carrying out a second
folding action of folding at least a portion of the web along its
longitudinal direction; after the second folding action, forming a
joint in the web, the joint being formed at least in a part of the
region in which the opposing margins have been brought together by
the second folding action; finally separating the web through the
joint to separate an individual absorbent article from the end of
the web.
Inventors: |
BACK; Lucas; (Billdal,
SE) ; Nilsson; Lennart; (Skarhamn, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCA Hygiene Products AB |
Goteborg |
|
SE |
|
|
Assignee: |
SCA Hygiene Products AB
Goteborg
SE
|
Family ID: |
42732276 |
Appl. No.: |
14/309322 |
Filed: |
June 19, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13578459 |
Sep 10, 2012 |
8815037 |
|
|
PCT/EP2010/051899 |
Feb 16, 2010 |
|
|
|
14309322 |
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Current U.S.
Class: |
604/385.01 ;
493/357 |
Current CPC
Class: |
A61F 13/4963 20130101;
Y10T 156/1051 20150115; B29C 66/0324 20130101; A61F 13/15747
20130101; A61F 13/15739 20130101; Y10T 156/1049 20150115; Y10T
156/1015 20150115; Y10T 156/1011 20150115; A61F 13/15699
20130101 |
Class at
Publication: |
604/385.01 ;
493/357 |
International
Class: |
A61F 13/15 20060101
A61F013/15 |
Claims
1. An apparatus for manufacturing an absorbent article, the
apparatus comprising: a feeder for feeding a longitudinal web of
web material along a machine direction, the web having two opposing
longitudinal edges, a first side and a second side, the web
furthermore having openings situated between the two opposing
longitudinal edges, the openings being spaced apart from one
another in the longitudinal direction of the web such that spaced
apart, opposing margins of web material are formed between the
respective opening and the opposing longitudinal edges of the web
material; a first folder for carrying out a first folding action of
folding the web about itself along its longitudinal direction such
that portions of the first side of the web face each other; a
second folder for carrying out a second folding action of folding
at least a portion of the web along its longitudinal direction to
bring together the opposing margins of web material such that they
face each other on the second side of the web; a joiner for forming
a joint in the web, the joint being formed at least in a part of
the region in which the opposing margins have been brought together
by the second folding action, the joint extending between the
longitudinal edges and the opening in the web, the joining means
being situated downstream of the first and second folding means;
and a separator for separating the web at the joint to separate an
individual absorbent article from the end of the web, the cutting
means being situated downstream of the third folding means.
2. The apparatus according to claim 1, further comprising a
pre-separator for pre-separating the web in the region where the
joint is formed while leaving at least a portion of the margins
unaffected to maintain the web integrity along its longitudinal
direction, the pre-separating means being situated downstream of
the joining means, the unaffected portion of the margins preferably
extending towards the longitudinal edges.
3. The apparatus according to claim 1, further comprising a third
folder for carrying out a third folding action of at least
partially reversing the second folding action such that at least
portions of the web folded in the second folding action face each
other on the first side of the web, the third folding means being
situated upstream of the separating means.
4. The apparatus according to claim 1, wherein the first folder is
provided by a first guide which extends in the machine direction,
the first guide being preferably provided in the form of a first
guide bar.
5. The apparatus according to claim 1, wherein the second folder is
provided by a second guide which extends in the machine direction,
second guide being preferably provided by two parallel second guide
bars which are spaced apart from one another.
6. The apparatus according to claim 1, wherein the third folder is
provided in the form of a third guide which extends in the machine
direction, the third guide being preferably provided in the form of
a guide bar.
7. The apparatus according to claim 6, wherein the third guide is
provided integral with the first guide, and is preferably provided
in the form of the first guide bar extending from an upstream
position to carry out the first folding action, towards a
downstream position, for carrying out the third folding action.
8. The apparatus according to claim 1, further including a holder
for holding the web when carrying out the third folding action, the
holding means being arranged in the vicinity of the third folding
means.
9. The apparatus according to claim 8, wherein the holder is
arranged to hold the web at two portions corresponding to two
consecutive joints of the web when carrying out the third folding
action.
10. The apparatus according to claim 9, wherein the holder is
provided by polygonal wheel, the corners of the polygonal wheel
being synchronised with the joiner such that the edges of the
polygonal wheel contact the web substantially at the joints.
11. The apparatus according to claim 9, wherein the holder is
provided in the form of an engaging mechanism, the engaging action
of which is arranged to be synchronised with the joiner such that
the engaging action takes place at the joints, the engaging
mechanism being preferably provided in the form of clamps, fingers,
paddles or of a belt pressing against fingers, paddles, or corners
of a polygonal wheel.
12. The apparatus according to claim 10, wherein the surfaces
between the corners of the polygonal wheel are concave.
13. The apparatus according to claim 9, wherein the holder is
provided with a vacuum that is intended to hold at least a part of
the web at the holder.
14. Disposable pants, manufactured with the apparatus according to
claim 1, the disposable pants including a longitudinal web of web
material, the web having two opposing longitudinal edges, a first
side and a second side, the web furthermore having openings
situated between the two opposing longitudinal edges, the openings
being spaced apart from one another in the longitudinal direction
of the web such that spaced apart and two opposing margins of web
material are formed between the respective opening and the opposing
longitudinal edges of the web material, the two opposing margins
being joined to one another at least in a part of the region of the
opposing margins and the resulting seam being at least partially
directed towards the inside of the disposable pants, wherein the
largest lateral dimension of the opening being larger than two
times the smallest lateral dimension of the smallest margin.
15. The apparatus of claim 1, wherein the absorbent articles are
disposable diaper pants or disposable incontinence pants.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a Division of application Ser. No.
13/578,459 filed on Sep. 10, 2012, which is a National Phase of
Application No. PCT/EP2010/051899 filed on Feb. 16, 2010. The
disclosures of the prior applications are hereby incorporated by
reference herein in their entirety.
TECHNOLOGICAL FIELD
[0002] The present invention pertains to a method of manufacturing
absorbent articles, in particular a method of manufacturing
disposable diaper pants or disposable incontinence pants, an
apparatus for manufacturing an absorbent article as well as a
disposable diaper or incontinence pant.
TECHNOLOGICAL BACKGROUND
[0003] Disposable pants for diapers or for incontinence products
are well-known products. For these, it has always been an aim to
equip them with a garment-like appearance, such that the diapers or
incontinence products, when worn by a user, have the outer
appearance of a conventional pant, in particular the appearance of
conventional underwear/undergarments.
[0004] One of the issues when mass-producing disposable pants of
this type is the appearance of the portion at which the front
portion and the rear portion are joined together at the sides. When
producing a seam of this kind, the typical issue that arises is
that the seam and any flange portion that inevitably is produced,
sticks out to the outside if the pants are worn by a user.
[0005] In order to improve the garment-like appearance of these
disposable pants, it is an aim that the side seam and the resulting
flange material does not stick out to the sides of the pants but
that these seams are not really visible on the outside.
[0006] Several attempts to achieve this have been carried out. WO
2004/062541 A1, for example, discloses a method of producing diaper
pants of disposable type, wherein the weld seams at the sides are
made such that the front portion and the rear portion overlap in a
manner such that the inner layer of the front portion is welded to
the outer layer of the rear portion. The resulting pant has a
garment-like appearance but the method requires advanced and
difficult handling of the diapers at the welding step.
[0007] U.S. Pat. No. 6,042,673 discloses a method of making a
flangeless seam for a disposable pant, wherein the step of actually
making the seam requires several complicated folding steps.
[0008] U.S. Pat. No. 5,074,854 discloses a disposable undergarment
having additional break-away panels which connect the front portion
and the rear portion along seams. The manufacturing process is
likewise complicated.
SUMMARY OF THE INVENTION
[0009] Starting from the technological background given above, it
is an object of the present invention to provide a method of
manufacturing absorbent articles, an apparatus for manufacturing
absorbent articles as well as a disposable diaper or incontinence
pant which allow for an improved and efficient manufacturing
process.
[0010] In claim 1, a method to achieve the above object is
provided. Accordingly, the method of manufacturing absorbent
articles comprises the steps of feeding a longitudinal web of web
material, the web having two opposing longitudinal edges, a first
side and a second side, the web furthermore having openings
situated between the two opposing longitudinal edges, the openings
being spaced apart from one another in the longitudinal direction
of the web such that spaced apart, opposing margins of web material
are formed between the respective opening and the opposing
longitudinal edges of the web material. A first folding action of
folding the web about itself along its longitudinal direction such
that portions of the first side of the web face each other is
carried out and a second folding action of folding at least a
portion of the web along its longitudinal direction to bring
together the opposing margins of web material such that they face
each other on the second side of the web is carried out. After the
second folding action, a joint is formed in the web, the joint
being formed at least in a part of the region in which the opposing
margins have been brought together by the second folding action,
the joint extending between the longitudinal edges and the opening
in the web. Finally, the web is separated through the joint to
separate an individual absorbent article from the end of the
web.
[0011] The method has the advantage that disposable pants, in
particular diaper or incontinence pants, can be manufactured in
which the joint between the layers of material and the resulting
flange material is at least in its main portion turned towards the
inside of the final product because the joint is formed at the two
second sides of the web. In other words, the side seams as well as
the resulting flange material are turned to the inside of the final
absorbent article. By means of the succession of the folding steps,
the production can be carried out in a continuous process at high
speed.
[0012] In order to support the final turning of the product, and in
particular of the seams, into its intended positioning with the
first side inside and the second side outside, the method after
forming the joint preferably further comprises the step of
pre-separating the web in the region where the joint is formed
while leaving at least a portion of the margins unaffected to
maintain the web integrity along its longitudinal direction, the
unaffected portion of the margins preferably extending towards the
longitudinal edges.
[0013] Preferably, the method further comprises the step of
carrying out a third folding action of at least partially reversing
the second folding action such that at least portions of the web
folded in the second folding action face each other on the first
side of the web, before separating the web. By means of the third
folding action, the product can be turned back into its intended
positioning with the first side inside and the second side outside
of the product, wherein the joint is then mainly situated inside
the final product. In other words, the side seams as well as the
resulting flange material are situated inside of the final
absorbent article such that the visual and haptic appearance of the
final absorbent article becomes more garment-like.
[0014] Preferably, a further step is carried out of holding the web
when carrying out the third folding action. There are different
options for holding the web when carrying out the third folding
action. In particular, the web can be held at two portions of the
web corresponding to two consecutive joints of the web, or it can
be held at a leading joint or a following joint, seen in the
direction of web feed, while carrying out the third folding
action.
[0015] The first folding action can be carried out efficiently
either by folding the web in the first folding action substantially
about its longitudinal center line, or by folding the web in the
first folding action substantially about a folding line which is
offset from its longitudinal center line.
[0016] In the second folding action, the web may be folded about a
line which is spaced apart from the respective longitudinal edges
of the web substantially by the width of the margin of the unfolded
web. In combination with the first folding action, this leads to a
substantially "M" cross-section of the folded web which enables an
efficient joining process. Preferably, the two opposing
longitudinal edges of the web are aligned with one another in or
after the second folding step such that a high-quality product can
be achieved.
[0017] In the second folding step, the two opposing portions may be
folded in a phase-shifted manner, in particular sequentially, in
order to avoid collision of the respective folding mechanisms.
[0018] To provide, in the final product, a seam which is as thin
and flexible as possible, in the step of forming a joint, the joint
may be provided in the form of two or more separate joining
portions such that at each individually cut final product only one
of the joining portions remains. Preferably, the two or more
separate joining portions are formed simultaneously in the web
material.
[0019] To be in a position to efficiently produce pants, before the
first folding action, preferably a further step is carried out of
providing the web with absorbent sections spaced apart in the
longitudinal direction on the first side of the web, the absorbent
section being situated between two respective openings.
[0020] An apparatus for carrying out the method described above is
claimed in claim 13. Accordingly, the apparatus comprises feeding
means for feeding a longitudinal web of web material along a
machine direction, the web having two opposing longitudinal edges,
a first side and a second side, the web furthermore having openings
situated between the two opposing longitudinal edges, the openings
being spaced apart from one another in the longitudinal direction
of the web such that spaced apart, opposing margins of web material
are formed between the respective opening and the opposing
longitudinal edges of the web material. The apparatus further
comprises a first folding means for carrying out a first folding
action of folding the web about itself along its longitudinal
direction such that portions of the first side of the web face each
other and a second folding means for carrying out a second folding
action of folding at least a portion of the web along its
longitudinal direction to bring together the opposing margins of
web material such that they face each other on the second side of
the web. Furthermore, the apparatus comprises a joining means for
forming a joint in the web, the joint being formed at least in a
part of the region in which the opposing margins have been brought
together by the second folding action, the joint extending between
the longitudinal edges and the opening in the web, the joining
means being situated downstream of the first and second folding
means, and a separating means for separating the web at the joint
to separate an individual absorbent article from the end of the
web, the cutting means being situated downstream of the third
folding means.
[0021] Preferably, a pre-separating means is provided to
pre-separate the web in the region where the joint is formed, while
leaving at least a portion of the margins unaffected to maintain
the web integrity along its longitudinal direction, the
pre-separating means being situated downstream of the joining
means, wherein the unaffected portion of the margins preferably
extends towards the longitudinal edges. The separation carried out
by the pre-separation means may help to ease the turning of the
final product into its intended orientation.
[0022] To turn the final product into its intended orientation, a
third folding means may be provided for carrying out a third
folding action of at least partially reversing the second folding
action such that at least portions of the web folded in the second
folding action face each other on the first side of the web, the
third folding means being situated upstream of the separating
means.
[0023] A reliable apparatus can be achieved if the first folding
means is provided by a first guide which extends in the machine
direction, the first guide being preferably provided in the form of
a first guide bar, and/or if the second folding means is provided
by a second guide which extends in the machine direction, the
second guide being preferably provided by two parallel second guide
bars which are spaced apart from one another. The same arrangement
can also be used with respect to the third folding means, which can
be provided in the form of a third guide extending in the machine
direction, the third guide being preferably provided in the form of
a third guide bar. Preferably, the third guide is provided integral
with the first guide, and is preferably provided in the form of the
first guide bar extending from an upstream position to carry out
the first folding action, towards a downstream position, for
carrying out the third folding action.
[0024] In order to further ease the turning of the product into its
intended orientation, the apparatus further includes a holding
means for holding the web when carrying out the third folding
action, the holding means being arranged in the vicinity of the
third folding means.
[0025] Preferably, the holding means is arranged to hold the web at
two portions corresponding to two consecutive joints of the web
when carrying out the third folding action.
[0026] Preferably, the holding means may be provided in the form of
a polygonal wheel, the edges of the polygonal wheel being
synchronised with the joining means such that the edges of the
polygonal wheel contact the web substantially at the joints.
Preferably, the holding means may also be provided in the form of
an engaging mechanism, the engaging action of which is arranged to
be synchronised with the joining means such that the engaging
action takes place at the joints, the engaging mechanism being
preferably provided in the form of clamps, fingers, paddles or of a
belt pressing against fingers, paddles or corners of a polygonal
wheel. In order to increase friction between the edges of the
polygonal wheel and the web, the surfaces between the corners of
the polygonal wheel are preferably concave. To securely hold the
web to the wheel, the holding means is preferably provided with a
vacuum means that is intended to hold at least a part of the web at
the holding means. Of course, vacuum means can also be provided
between the respective corners of the wheel in order to hold the
remaining portion of the web closely to the wheel. This specific
embodiment facilitates carrying out the third folding action
because the vacuum sucks one side of the folded web towards the
wheel and provides for a minute separation of the respective first
sides of the web such that a gap is opened through which the web
can be pass in the third folding action.
[0027] Disposable pants according to claim 26 are provided. The
disposable pants include a longitudinal web of web material, the
web having two opposing longitudinal edges, a first side and a
second side. The web furthermore having openings situated between
the two opposing longitudinal edges, the openings being spaced
apart from one another in the longitudinal direction of the web
such that spaced apart and two opposing margins of web material are
formed between the respective opening and the opposing longitudinal
edges of the web material. The two opposing margins being joined to
one another at least in a part of the region of the opposing
margins and the resulting seam being at least partially directed
towards the inside of the disposable pants, wherein the largest
lateral dimension of the opening being larger than two times the
smallest lateral dimension of the smallest margin.
[0028] A disposable pant of this type has the advantage that it has
a garment-like feel and appearance and it can be effectively
produced by means of the method and/or apparatus described
above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In the following, embodiments of the apparatus for and the
method of manufacturing absorbent articles are disclosed in the
attached Figures, in which:
[0030] FIG. 1 shows a first portion of an apparatus of a first
embodiment;
[0031] FIG. 2 shows a first alternative of a second portion of the
apparatus of FIG. 1;
[0032] FIG. 3 shows a second alternative of the second portion of
the apparatus of FIG. 1;
[0033] FIGS. 4 to 11 show schematically an embodiment of the method
of manufacturing an absorbent article;
[0034] FIG. 12 shows different variants of joints in the
product;
[0035] FIG. 13 shows an alternative embodiment of a holding
means;
[0036] FIG. 14 shows yet another embodiment of a holding means;
[0037] FIG. 15 shows another variant of a holding means;
[0038] FIG. 16 shows an absorbent article manufactured by the
method;
[0039] FIG. 17 shows different arrangements of the first and second
guide bars; and
[0040] FIG. 18 shows an alternative embodiment for carrying out the
third folding action.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] In the following, preferred embodiments of the present
disclosure will be described by means of reference to the attached
Figures. In the Figures, like or same elements will be denoted by
the same reference numerals and repeated description thereof may be
omitted in order to avoid redundancies.
[0042] FIG. 1 shows a first, upstream, portion of a manufacturing
apparatus 100 according to the present disclosure, which is
intended to manufacture absorbent articles, and, in particular,
disposable diaper pants and/or incontinence pants.
[0043] A longitudinal web of web material 1 is fed along the
feeding direction X, which is also the machine direction MD. The
web 1 has a first side 10 and a second side 12. The web 1 comprises
two opposing longitudinal edges 14 and is provided with openings 16
which are spaced apart from one another and which are provided
fully inside the boundaries provided by the web of material 1.
Between the openings 16 and the two longitudinal edges 14, opposing
margins 18 of web material are present. The margins are intended to
be defined in the area between the dotted lines, i.e. the margins
extend in a cross-machine direction CD between any portion of the
opening 16 and the respective longitudinal edge 14 of the web
1.
[0044] An absorbent core 19 is placed between two consecutive
openings 16 in the web 1. The absorbent core may extend into the
margins of web material.
[0045] A feeding means for feeding the web 1 is provided, which is,
however, not shown in FIG. 1. The feeding means may be a roller
from which the readily-manufactured web including the openings 16
and the absorbent cores 19 is unrolled. The feeding means may also
be provided in any upstream station in the production process from
which the web 1 with at least the selected features discussed above
is fed to the apparatus 100.
[0046] After the feeding means, a first folding means 2 is
provided, which carries out a first folding action of folding the
web 1 about itself along its longitudinal direction X, such that
portions of the first side 10 of the web material face each other.
In the embodiment shown in FIG. 1, the web 1 is folded upon itself
such that the two opposing longitudinal edges 14 are actually
aligned with one another, as can be seen at reference numeral 20.
However, this very specific alignment is not essential for the
method.
[0047] The first folding means 2 is provided in the form of a guide
bar 22, which extends, at least in its effective folding portion,
along the feeding direction X and the machine direction MD of the
apparatus 100. The first guide bar 22 provides a clear-cut edge or
axis about which the web 1 can be folded lengthwise.
[0048] In addition to the first guide bar 22, a folding plough or
folding boards are intended to be present, which are, however, not
shown for clarity reasons in FIG. 1. The folding boards or the
folding plough are intended to bring together the opposing edges 14
or, at least, the opposing margins 18 of the web 1 in the form as
shown at reference numeral 20.
[0049] Downstream of the first folding means 2, a second folding
means 3 is present, which affects a second folding action for
folding at least a portion of the web 1 along its longitudinal
direction to bring together the opposing margins of the web
material, such that they face each other on the second side 12 of
the web.
[0050] The readily-folded web, folded by the second folding means,
can be seen at reference numeral 30. At this position, the folded
web 1 has, substantially, an "M"-shape in cross-section. It is to
be noted that the margins 18 can be and, preferably, are brought
together directly at the position of reference numeral 30 and at
the second side 12 of the web, because the openings 16 of the web 1
permit a direct contact of the two margins 18 at reference numeral
30.
[0051] The second folding means is provided by means of two second
guide bars 32, which likewise extend along the feeding direction X
and which are spaced apart from one another slightly in the plane
defined by the unfolded web 1 and are spaced apart from the first
guide bar 22 in the direction perpendicular to the unfolded web by
a distance d in the height-direction in the Figure.
[0052] Distance d is set, in the embodiment of the apparatus shown
in FIG. 1, such that the margins 18 can be brought together fully
without the opposing longitudinal edges 14 touching the lower bar
22. Accordingly, the distance d is at least the distance of the
smallest portion of the margin 18 plus the extension of the
respective guide bars 22, 32.
[0053] A joining means 4 is present in order to form a joint in the
web, wherein the joint is formed in at least a part of the region
in which the opposing margins 18 have been brought together by the
second folding action at the second folding means 3.
[0054] In the illustrated embodiment, the joint in the web 1 is
provided in the web by means of an ultrasonic welding tool 40
having a welding horn 42, which fits between the first guide bar 22
and the second guide bar 32. Naturally, other joining means
well-known in the art may be used. In the present case, the welding
horn 42 enables welding the opposing margins 18 together. It is to
be noted that the welding process takes place substantially through
the opening 16 of the web 1, such that only the opposing margins 18
are welded together and, thus, only two layers of material are
joined to one another.
[0055] The welding horn 42 works against a welding cylinder 44,
which is synchronised with the web and in particular synchronised
with the succession of the respective openings 16 in order to be in
a position to produce a joint between the then to be cut individual
absorbent articles.
[0056] Downstream of the joining means 4, a pre-separating means 5
for pre-separating the web in the region where the joint is formed
is present. The pre-separating means 5 is provided in the form of
rotating knives 50, which cut the web at the region where the joint
46 is provided in the web 1. As can be seen at reference numeral
50, the pre-separating step leads to a situation in which a part of
the web is already pre-separated, but a portion of the joint 46
remains intact on both opposing portions of the cut. At the
opposing longitudinal edge 14 of the web, at reference numeral 50,
a small portion of the margin 18 remains unseparated, in order to
maintain the web integrity along its longitudinal direction.
[0057] Furthermore, at reference numeral 50, the two second guide
bars 32 terminate, such that the folds that were created at the
second folding means 3 are no longer guided by the second guide
bars 32. However, in other embodiments the second guide bars may
also terminate in other sections of the apparatus such as directly
after the first folding action or as late as immediately before the
third folding action.
[0058] The first guide bar 22, however, remains and still guides
the fold that was created at the first folding means 2.
[0059] In FIG. 2, a first alternative of the process of unfolding
the folds and turning the joined portion towards the inside of the
final product is shown.
[0060] In particular, a holding means 6 is provided which is shown
in FIG. 2 as a clamping means 60. The clamping means 60 grips the
pre-cut web 1 at the respective consecutive joints 46 in the web 1
substantially at the waist band portion 140 of the folded web, such
that a single individual absorbent article is clamped between two
consecutive clamps 60.
[0061] A third folding means 7 is provided downstream of the
holding process. The third folding means carries out an unfolding
of a crotch section of the absorbent article provided with the
absorbent core 19, such that the folding process that was carried
out at the second folding means 3 is at least partially reversed.
In particular, the region of the opposing margins 18 that were
folded upon one another at the second folding means 3 are now
folded back into an orientation in which the respective first sides
10 of the web face each other.
[0062] The third folding means 7 is provided, in FIG. 2, by means
of the first guide bar 22, wherein the first guide bar 22 bends
away downwardly, such that the crotch portion is pulled out of its
M-folded configuration. At the opposing side edges 14, a waist band
portion remains.
[0063] A separating means 8 is provided downstream of the third
folding means 7, wherein the separating means 8 completely
separates individual absorbent articles from the web.
[0064] As will be appreciated, the final absorbent product, which
is preferably a disposable diaper pant or a disposable incontinence
pant, has a structure in which the majority of the joint 46, which
was provided at the joining means 4, is now located inside of the
absorbent article. In particular, the majority of the flange
material 460 remaining at the joint 46 is situated inside the final
pants. The last small portion, which corresponds to a waist band
portion, remains folded to the outside but can be likewise
re-folded in order to achieve an absorbent article in which the
entire joint, and in particular the flange resulting from the
cutting action, is situated inside the absorbent article.
[0065] FIG. 3 shows an alternative to the clamps 60 of FIG. 2. The
holding means 6 in FIG. 3 is provided in the form of a polygonal
wheel 62, having corners 64. The polygonal wheel 62 has a length of
each of the sides of the polygon which corresponds to a distance
between two consecutive joints 46. Furthermore, the polygonal wheel
62 is synchronised with the joints such that each joint 46 of the
web is associated with one of the corners 64 of the polygonal
wheel. Preferably, the sides of the polygonal wheel between the
corners 64 are slightly concave in order to increase the friction
at the corners 64.
[0066] The polygonal wheel 62 is adapted to hold the respective
absorbent article at the respective joints 46 during the third
folding action. The third folding means 7 is shown in FIG. 3, again
as the first guide bar, which bends away from the initial position
in order to pull out the crotch portion of the absorbent
article.
[0067] To support holding the web at the waist band portion 140,
the polygonal wheel 62 may also be provided with vacuum means,
either at the corners, between the corners or in a circumferential
arrangement, such that the waist band portion 140 can by closely
sucked to the wheel 62.
[0068] With reference to FIGS. 4 to 11, the method of manufacture
is explained again in more detail.
[0069] In particular, in FIG. 4, the web 1 with openings 16,
absorbent cores 19, opposing side edges 14 and margins 18 is shown.
Furthermore, a waist band section 17 is also shown in FIG. 4 and
the feeding direction is, this time, from the left-hand side to the
right-hand side along the direction indicated by arrow X.
[0070] FIG. 5 shows a first folding action by means of a first
guide bar 22, wherein the web 1 is folded lengthwise such that the
opposing side edges 14 are brought together such that the margins
18 overlap at the first side 10 of the web.
[0071] The then folded web as shown in FIG. 6 is to be carried
along the feeding direction X.
[0072] In FIG. 7, a second folding process at folding means 3 is
shown, wherein second guide bars 32 are provided. As can be seen,
the portions of the margins 18 are folded downwards again, about
the edge provided by the second guide bars 32, wherein in FIG. 7
only the first portion of the web 1 is folded downwards and in FIG.
8 it is shown that also the other side of the web is folded
downwards. In other words, the opposing portions of the web are
folded sequentially.
[0073] In FIG. 9, it is shown that the two margins 18 overlap
through the openings 16 of the web and a joint 46 is formed at the
joining means 4. The joint shown in FIG. 9 comprises of two
separate seams 46' and 46'', and in the pre-separation step 5, a
cut is carried out between the first seam 46' and the second seam
46'', however, leaving the waist band portion 17 unseparated, in
order to maintain the structural integrity of the web.
[0074] In FIG. 10, the third folding process at the third folding
means 7 is shown, wherein the first guide bar 22 simply bends away
from its original path, such as to pull downwards the crotch
section of the absorbent article, such that the material folded in
the second folding action is actually reversed with respect to its
orientation.
[0075] The resulting absorbent article is shown in FIG. 11, in
which, at station 8, a final cut is carried out to separate
individual absorbent articles from the web.
[0076] It is to be noted that the waist band 70 is still in the
folded position as carried out in the second folding step. However,
the majority of the joint 46' and 46'' is folded back so that the
flange material situated between the first seam 46' and the second
seam 46'' actually points towards the inside.
[0077] FIG. 12 shows different variants of forming a joint 46. In
particular, the joints at the right hand side of the Figure are
provided in the form of full joints in which a relatively large
area of the web is joined together. The joints 46 shown on the left
hand side of the Figure are provided in the form of separated
welding spots which are situated more or less symmetrical to the
intended separating line 80 such that unbonded material remains in
the flange portions 460. This unbonded material in the flange
portions 460 has the advantage that the joints have a softer feel
to the skin.
[0078] FIG. 13 shows an alternative to the polygonal wheel 62 shown
in FIG. 3. Here, the web 1 is held at the respective joints by
means of paddles 66 which are driven on a chain belt 660.
[0079] FIG. 14 shows yet another embodiment of a holding means 6,
namely in the form of paddles 68 which press against a conveyer
belt 680 at the positions of the respective joints 46.
[0080] As shown in FIG. 15, in order to ensure a secure conveying
during the third folding process, a groove 63 can be provided in a
substantially round wheel 65, wherein in the groove 63 the waist
band portion 140 can be situated while the third folding action is
carried out. The waist band portion 140 may be pressed into the
groove 63 by means of a holding belt 630 which is situated
substantially in the same position as the groove 63 and presses the
waist band portion 140 towards the wheel 65.
[0081] In FIG. 16, an individual absorbent article 9 is shown, in
its reversed state such that the absorbent core 19 points towards
the outside and it is the first side 10 that points towards the
outside. The two seams 46' and 46'' are shown, which leave flange
material 460 remaining at the outside. This flange material 460
points towards the inside of the pant when it is in its final
arrangement.
[0082] Because a first separation step and a second separation step
are carried out at two consecutive absorbent articles, the cut at
the flange 460 shows an irregular edge 462 which may have kinks 464
in it. Furthermore, the absorbent article shown on the right-hand
side of FIG. 16 shows an asymmetric irregularity on its left- and
right-hand sides of flange 460.
[0083] FIG. 17 shows exemplarily cross sections through the
arrangement of the first guide bar 22 and the second guide bars 32,
33 in different arrangements. It is noted that the distance between
the first guide bar 22 and the respective third guide bars 32, 33
is determined, inter alia, by the lateral distance of the margins
18. This dimensional restriction is necessary in order to carry out
the joining step by means of the welding horn 42 as shown in FIG. 1
such that only two layers of the material are joined to one
another, substantially through the opening 16.
[0084] In fact, in order to be in a position to carry out the
method shown schematically in FIG. 1, the maximum lateral size of
the opening 16 has to be larger than two times the smaller of the
margins 18. Typically, the margins 18 have the identical lateral
extension such that the opening 16 needs to be larger at the
position in which the joint is to be formed than twice the lateral
extension of the margins 18.
[0085] The different arrangements shown in FIG. 17 do not only
accommodate for asymmetric shapes of the opening 16 such as to
provide larger coverage of the disposable pants at the back side
than at the front side, but also accommodate for different
arrangements of the apparatus.
[0086] FIG. 18 shows yet another embodiment of an apparatus for
carrying out the third folding action. In particular, the absorbent
article is still guided by the first guide bar 22 at its crotch
portion and the waist band portion 140 is guided by two rollers
620, 622. In order to carry out the third folding action, namely to
unfold the pants, the first guide bar 22 is guided away from the
plane in which the waist band portion 140 of the absorbent article
is guided and held by the two rollers 620, 622 such that the third
folding action is carried out and the crotch portion is unfolded
such that the seams at the joints are turned at least partially
towards the inside of the final pants.
* * * * *