U.S. patent application number 10/401688 was filed with the patent office on 2004-02-12 for method for production of diaper pants.
This patent application is currently assigned to SCA Hygiene Products AB. Invention is credited to Erwast, Lennart, Fernfors, Ingemar, Karlsson, Birgitta, Skogsberg, Johan, Widlund, Urban.
Application Number | 20040030318 10/401688 |
Document ID | / |
Family ID | 31498316 |
Filed Date | 2004-02-12 |
United States Patent
Application |
20040030318 |
Kind Code |
A1 |
Karlsson, Birgitta ; et
al. |
February 12, 2004 |
Method for production of diaper pants
Abstract
Method for producing disposable diaper-pants having openable and
resealable side panels. Absorption bodies are applied on a
continuous web of inner or outer coversheet material so that front
portions and rear portions of adjacent diaper-pants blanks in a web
are directed toward each other. A continuous web of outer or inner
coversheet material is applied to and secured to the web with
absorption bodies. Separate side panels connected to each other by
a detachable and resealable connection are secured to side portions
of the adjacent front portions or rear portions of the diaper
pants. Each diaper-pants blank with side panels is cut from the web
and folded about a transverse axis in the crotch with the front and
rear edges lying against each other. The side panels of each blank
are folded toward and secured to side portions of the rear or front
portion which have no side panel.
Inventors: |
Karlsson, Birgitta;
(Molndal, SE) ; Skogsberg, Johan; (Goteborg,
SE) ; Erwast, Lennart; (Goteborg, SE) ;
Widlund, Urban; (Pixbo, SE) ; Fernfors, Ingemar;
(Molndal, SE) |
Correspondence
Address: |
BURNS, DOANE, SWECKER & MATHIS, L.L.P.
P.O. Box 1404
Alexandria
VA
22313-1404
US
|
Assignee: |
SCA Hygiene Products AB
Goteborg
SE
|
Family ID: |
31498316 |
Appl. No.: |
10/401688 |
Filed: |
March 31, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60368964 |
Apr 2, 2002 |
|
|
|
Current U.S.
Class: |
604/387 ;
156/226; 156/227; 156/250; 156/264; 156/301; 604/396 |
Current CPC
Class: |
A61F 13/496 20130101;
A61F 13/565 20130101; Y10T 156/1015 20150115; Y10T 156/1052
20150115; Y10T 156/1095 20150115; Y10T 156/1075 20150115; Y10T
156/1051 20150115; A61F 13/15699 20130101; Y10T 156/1049 20150115;
A61F 13/15747 20130101 |
Class at
Publication: |
604/387 ;
156/226; 156/227; 156/264; 156/250; 156/301; 604/396 |
International
Class: |
A61F 013/15; B31F
001/00; B32B 031/00 |
Claims
What is claimed is:
1. A method for production of disposable diaper pants or of a
sanitary panty of the disposable type with openable and resealable
side panels, the method comprising: forming a web of interconnected
diaper pants blanks, each diaper pants blank having an absorption
body enclosed between an inner cover sheet of liquid-permeable
material and an outer cover sheet of liquid-impermeable material
and having a front portion and a rear portion and an intermediate
crotch portion, by applying a row of absorption bodies being
applied on a continuous web of inner or outer cover sheet material
so that the front portions and the rear portions of adjacent diaper
pants blanks in the web of interconnected diaper pants blanks are
directed toward each other, thereafter applying a continuous web of
outer or inner cover sheet material to the web with absorption
bodies and secured to it in those parts thereof which lie outside
the absorption bodies; securing separate side panels connected to
each other to the side portions of each of the adjacent front
portions or each of the adjacent rear portions of the diaper pants
blanks, each side panel comprising two parts which are connected to
each other by means of a detachable and resealable connection;
cutting out individual diaper pants blanks having side panels from
the web of interconnected diaper pants blanks; folding each diaper
pants blank about a transverse axis in the crotch portion so that
the front and rear edges of the blank lie against each other; and
thereafter folding the side panels of each diaper pants blank in
toward those side portions of either the rear portion or front
portion which have no side panel and are secured thereto.
2. The method according to claim 1, wherein the side panels are
secured to the outer or inner cover sheet of the diaper pants
blanks.
3. The method according to claim 1, wherein the side panels are
placed between the outer and inner cover sheets of the web of
connected diaper pants blanks and are secured to both of these
sheets.
4. The method according to claim 1, wherein the side panels at
least partially comprise an elastic material.
5. The method according to claim 1, wherein the detachable and
resealable connection, which connects the two parts of each side
panel to each other, is a childproof connection.
6. The method according to claim 1, wherein in addition to the
detachable and resealable connection, each side panel also
comprises a second childproof connection which is detachable and
which is destroyed when the side panel is opened for the first
time.
7. A disposable diaper pants or a sanitary panty of the disposable
type with a front portion, a rear portion and an intermediate
crotch portion, the diaper pants or sanitary panty comprising: an
absorption body enclosed between an inner cover sheet of
liquid-permeable material and an outer cover sheet of liquid-tight
material; and separate side panels which, on both sides of the
absorption body, extend outside the inner and outer cover sheets
and connect the front and rear portions of the diaper pants or
sanitary panty to each other, so that the diaper pants or sanitary
panty acquire a pants-like configuration with a waist opening and
two leg openings, each of the side panels being elastic and
comprising two parts which are connected to each other by means of
a detachable and resealable connection member.
8. The diaper pants or sanitary panty according to claim 7, wherein
the detachable and resealable connection comprises a childproof
connection member.
9. The diaper pants or sanitary panty according to claim 7, wherein
in addition to the detachable and resealable connection, each side
panel also comprises a second childproof connection, which is
detachable and is destroyed upon opening the side panel for the
first time.
10. The diaper pants or sanitary panty according to claim 7,
wherein the elastic side panels comprise parts of nonelastic
material in those sections to which parts of the detachable and
resealable connection are secured.
11. The diaper pants or sanitary panty according to claim 8,
wherein the force needed to open the childproof connection is
greater than 4 N.
12. The diaper pants or sanitary panty according to claim 7,
wherein an overlap of the two parts of each side panel which are
connected to each other by means of a detachable and resealable
connection member protrudes beyond the connection member and forms
a grip tab with an extent of 3-7 mm.
13. The diaper pants or sanitary panty according to claim 8,
wherein the force needed to open the childproof connection is
greater than 6N.
14. The diaper pants or sanitary panty according to claim 8,
wherein the force needed to open the childproof connection is
greater than 8N.
15. The diaper pants or sanitary panty according to claim 8,
wherein the force needed to open the childproof connection is
greater than 10N and less than 20N.
16. The diaper pants or sanitary panty according to claim 8,
wherein the force needed to open the childproof connection is about
15N.
17. The diaper pants or sanitary panty according to claim 7,
wherein an overlap of the two parts of each side panel which are
connected to each other by means of a detachable and resealable
connection member protrudes beyond the connection member and forms
a grip tab with an extent of 4-6 mm.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Application No. 60/368,964, filed in the United States
on Apr. 2, 2002, the entire contents of which are hereby
incorporated herein by reference.
BACKGROUND OF THE APPLICATION
[0002] 1. Technical Field
[0003] The present invention relates to a method for production of
disposable diaper pants or of a sanitary panty of the disposable
type with openable and resealable side panels, and to diaper pants
or a sanitary panty produced by means of this method.
[0004] 2. Background Art
[0005] Diaper pants with openable and resealable side panels
combine the advantages of conventional diaper pants and
conventional diapers. They are produced with sealed side panels
and, like conventional diaper pants, can be taken off and put on in
the same way as underpants. By means of the side panels being
openable, they can also be taken off in the same way as
conventional diapers, as a result of which they can be changed
without underpants, shoes and stockings having to be taken off, and
soiling of the infant can be avoided when changing the diaper
pants. Moreover, the fact that they are resealable means that a
parent can open the diaper pants in order to check whether they
need to be changed and can seal the diaper pants again if this is
not the case. It is therefore of advantage to be able to produce
such diaper pants in an economic way.
[0006] SE-C2-508 613 discloses a method for producing diaper pants
from a web of continuous diaper pants blanks, in which the blanks
are arranged side by side. In this method, the whole web of diaper
pants blanks is folded so that front edges and rear edges lie
edge-to-edge, and the side portions of the folded diaper pants
blanks are secured to each other with the aid of a folded band. The
folded band can be in two parts, said two parts being connected to
each other by means of a detachable and resealable connection. The
band does not normally form separate side panels, but it is stated
that bands folded in a bellows fashion can be used if it is desired
to use parts of the bands to form side panels. Such folding in a
bellows fashion complicates the method and requires great precision
when applying the bellows-folded bands. The document also mentions
that, in the case of a web of continuous diaper pants blanks in
which the diaper pants blanks are arranged one after another, it is
possible to connect the side portions of individual diaper pants
blanks to each other with the aid of folded bands. Such a method
requires great precision both when applying the bands and when
cutting the individual diaper pants blanks from the web of
continuous diaper pants blanks.
[0007] WO 99/65439, WO 99/65441, WO 00/37007 and WO 00/37010 all
disclose methods for producing diaper pants in which side panels
are fastened in a detachable and resealable manner to side portions
of the unit of the diaper pants which encloses the absorption body.
These methods too require great precision when applying the side
panels and when cutting the individual diaper pants blanks from the
web of continuous diaper pants blanks. These methods also make it
difficult to design the openable and resealable connection as a
childproof connection.
[0008] It is an object of the present invention to make available a
method for production of disposable diaper pants or of a sanitary
panty of the disposable type with openable and resealable side
panels, said method requiring less precision than in previously
known methods when applying side panels to a web of continuous
diaper pants blanks arranged in succession, and when subsequently
cutting individual diaper pants blanks from the web. A further
object is to permit application of childproof connections in a
simple manner.
SUMMARY OF THE INVENTION
[0009] These and other objects are achieved by means of a method
for production of disposable diaper pants or of a sanitary panty of
the disposable type with openable and resealable side panels.
[0010] A web of interconnected diaper pants blanks, which each
comprise an absorption body enclosed between an inner cover sheet
of liquid-permeable material and an outer cover sheet of
liquid-impermeable material and have a front portion and a rear
portion and an intermediate crotch portion, is formed by applying a
row of absorption bodies on a continuous web of inner or outer
cover sheet material so that the front portions and the rear
portions of adjacent diaper pants blanks in the web of
interconnected diaper pants blanks are directed toward each other,
after which a continuous web of outer or inner cover sheet material
is applied to the web with absorption bodies and secured to it in
those parts thereof which lie outside the absorption bodies.
[0011] Separate side panels connected to each other are secured to
the side portions of each of the adjacent front portions or each of
the adjacent rear portions of the diaper pants blanks, each side
panel comprising two parts which are connected to each other by
means of a detachable and resealable connection. Individual diaper
pants blanks provided with side panels are cut out from the web of
interconnected diaper pants blanks. Each diaper pants blank is
folded about a transverse axis in the crotch portion so that the
front and rear edges of the blank lie against each other.
Thereafter the side panels of each diaper pants blank are folded in
toward those side portions of either the rear portion or front
portion which have no side panel and are secured thereto.
[0012] Because the diaper pants blanks are arranged so that the
front portion of one blank adjoins the front portion of the
preceding or subsequent blank and the rear portion of one blank
adjoins the rear portion of the subsequent or preceding blank, the
blanks can have the same width at the locations for division. This
means that the precision requirements for division are reduced
compared to the situation where parts with different widths are to
be divided. The precision requirements for application of side
panels are also reduced. Moreover, the application of two-part side
panels means that the connection between the two parts can be made
childproof before the application of the side panels to the web of
diaper pants blanks.
[0013] In a preferred embodiment, the side panels are secured to
the outer or inner cover sheet of the diaper pants blanks.
Alternatively, the side panels are placed between the outer and
inner cover sheets of the web of connected diaper pants blanks and
are secured to both of these sheets. The side panels preferably
comprise at least partially an elastic material, and the detachable
and resealable connection, which connects the two parts of each
side panel to each other, comprises a childproof connection. In one
variant, in addition to the detachable and resealable connection,
each side panel also comprises a second childproof detachable
connection, which is destroyed when the side panel is opened for
the first time.
[0014] Embodiments of the invention also relate to disposable
diaper pants or a sanitary panty of the disposable type with a
front portion, a rear portion and an intermediate crotch portion,
which comprises an absorption body enclosed between an inner cover
sheet of liquid-permeable material and an outer cover sheet of
liquid-tight material and separate side panels which, on both sides
of the absorption body, extend outside the inner and outer cover
sheets and connect the front and rear portions of the diaper pants
to each other, so that the diaper pants acquire a pants-like
configuration with a waist opening and two leg openings. Each side
panel is elastic and comprises two parts which are connected to
each other by means of a detachable and resealable connection
member.
[0015] In a preferred embodiment, the detachable and resealable
connection comprises a childproof connection member, and the
elastic side panels include parts of nonelastic material in those
sections to which parts of the connection members are secured. In
one variant, in addition to the detachable and resealable
connection, each side panel comprises a second childproof
detachable connection, which is destroyed upon opening the side
panel for the first time. The force needed to open the childproof
connection is greater than 4 N, preferably greater than 6 N, more
preferably 8 N, and most preferably 10 N but less than 20 N,
preferably about 15 N.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will now be described with reference to the
attached figures, of which:
[0017] FIGS. 1 and 2 are diagrammatic representations, in a side
view and plan view respectively, of an arrangement for producing
diaper pants according to a first embodiment of the invention,
[0018] FIG. 3 shows a diagrammatic perspective view of diaper pants
produced in an arrangement according to FIGS. 1 and 2,
[0019] FIG. 4 shows a cross-sectional view along the line IV-IV in
FIG. 3, and
[0020] FIG. 5 is a diagrammatic representation of a method for
testing the childproof nature of a connection.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIGS. 1 and 2 are diagrammatic representations of an
arrangement for producing the diaper pants according to FIG. 3. The
diaper pants shown in FIG. 3 comprise an absorption body 1 enclosed
between an inner cover sheet 2 of liquid-permeable material and an
outer cover sheet 3 of liquid-tight material. The cover sheets 2
and 3 are connected to each other by adhesive bonding or welding in
parts lying outside the absorption body. The unit 7 formed by the
cover sheets and the absorption body has a front portion 4, a rear
portion 5 and an intermediate narrower crotch portion 6. The diaper
pants 3 also comprise side panels 8, 9 which extend between the
front and rear portions of the unit 7 lying on the same sides of
the absorption body and connect these portions to each other so
that the diaper pants acquire a form similar to underpants.
[0022] The side panels 8, 9 comprise two parts 10, 11 and 12, 13,
respectively, which parts overlap each other and are connected to
each other by means of a detachable and resealable mechanical
connection 14 in the overlapping portions. In the example shown,
the connection 14 is or is similar to a VELCRO.TM. type connection,
i.e., one part 10 is provided with a fastening element 15, or male
element, having a number of hooks which project outward from the
surface of the fastening element, and the other part 11 is provided
with a fastening element 16, or female element, having a number of
loops or eyelets in which the hooks engage. In the illustrative
embodiment shown, some of the hooks of the male element are also
firmly connected to the female element, e.g. firmly welded in the
female element by point welding. In this way it is possible to
obtain a connection which is difficult or impossible for an infant
to open but is easy for an adult to open. It has indeed been found
that infants like to manipulate their diaper pants, and for this
reason there is a need for a childproof connection. The number of
weld points should be chosen so that the force needed to open such
a connection is greater than 4 N, preferably greater than 6 N, more
preferably greater than 8 N, and most preferably greater than 10 N
but less than 20 N, preferably less than 15 N, in order to ensure
childproofing and yet make the connection easy for an adult to
open. The opening force can be easily measured, in the manner shown
diagrammatically in FIG. 5, by coupling a weight to that part of
the two parts of the connection which is overlapped, and thereafter
taking hold of the grip part of the overlapping part and then
lifting the connection. If the weight remains suspended from the
connection for more than 30 seconds without the connection opening,
the connection is considered sufficient to hold the weight.
[0023] Another factor which influences the childproof aspect is the
length of the grip tab, i.e. the length a (see FIG. 5) of that part
of the overlapping side panel which projects beyond the connection.
It has been found that if the grip tabs are shorter than 7 mm, it
is very difficult for the children themselves to open the
connection. For this reason, the length of the grip tab should lie
between 3 and 7 mm, preferably between 4 and 6 mm.
[0024] The childproofing can also be obtained in another way by
means of the fact that, outside the mechanical connection 14, the
overlapping portions of the two parts 10, 11 and 12, 13,
respectively, of the side panels are connected to each other by
means of a second openable but not resealable connection, for
example a weld connection or adhesive connection, with an opening
force in accordance with the above. A second connection of this
kind is destroyed when the side panels are opened for the first
time. The outermost edge part of the overlapping part of the two
parts 10, 11 and 12, 13, respectively, can also be firmly connected
to the underlying part of the side panel, in which case opening is
obtained by means of a line of weakening in the overlapping part
situated between the connection 14 and the firmly connected
outermost edge part.
[0025] The two-part side panels 8, 9 can be elastic and are
preferably made of elastic material, except in those parts which
include the securing elements 15, 16, which parts are preferably
made of nonelastic material. The elastic material can include, for
example, elastics made from block copolymers, such as
polyurethanes, copolyether esters, polyamide-polyether block
copolymers, ethylene-vinyl acetates (EVA) and the like, including
polyurethanes available from E. I. Du Pont de Nemours Co., USA,
under the name LYCRA.RTM. (also known as "spandex"); elastomeric
styrene-butadiene copolymers, including those such as KRATON.RTM.
material, which are available from Shell Chemical Company of
Houston, Tex., USA; tetra-block copolymers, including elastomeric
styrene-poly(ethylenepropylene) block copolymers available from
Shell Chemical Company of Houston, Tex., USA, under the trade name
KRATON.RTM.; polyamides including polyether block amides available
from Ato Chemical Company, USA, under the trade name PEBAX.RTM.;
polyesters, such as those available from E. I. Du Pont de Nemours
Co. under the trade name HYTREL.RTM.; single-site or
metallocene-catalyzed polymers, including single-site or
metallocene-catalyzed polyolefins with a density of less than about
0.89 gram/cm.sup.3 from Dow Chemical Co., USA, under the trade name
AFFINITY.RTM.; and natural and synthetic rubber. The nonelastic
material can be, for example, a nonwoven material, for example a
spunbond nonwoven, a carded nonwoven, a meltblown nonwoven or a
nonwoven laminate, for example a spunbond-meltblown-spunbond (SMS)
laminate. The fibers used to build up the nonwoven materials can be
fibers of polyolefins, for example polyethylene or polypropylene,
or of polyester. Moreover, the nonwoven material can be a mixture
of several different types of fibers, or of fibers which has
several different polymers, called copolymers. It is also possible
for the nonelastic material to be a plastic film. In the preferred
embodiment, therefore, at least the parts 11 and 13 of the two 10,
11 and 12, 13, respectively, of which the side panels 8, 9 consist,
are in turn made up of at least two parts. For the sake of
simplicity, however, the parts 10, 11 and 12, 13, respectively, are
shown as single material pieces in the figures.
[0026] The aim of the elastic side panels is to give the diaper
pants a good fit. The side panels are dimensioned to give the
elastic force necessary, but not more. It is therefore conceivable
that the side panels also have parts of nonelastic material at
locations other than at the securing elements.
[0027] As material for the side panels, it is also conceivable to
use two nonwoven sheets between which elastic material, elastic
bands or elastic threads are secured in the stretched state. With
such a material, the elastic and nonelastic parts of the side
panels include portions with and without such elastic material.
[0028] To improve access to the detachable and resealable
connections 14, the parts 11 and 13 can have a considerably greater
extent in the circumferential direction than the parts 10 and 12,
respectively, cooperating with them. In this way, the connections
14 will be situated on the front of the diaper pants, which makes
them easier to get access to for a parent who wishes to open or
take off the diaper pants from an infant lying on his/her back. In
the embodiment shown in FIG. 3, the parts 10 and 12 which have a
small extent in the circumferential direction are advantageously
made entirely of nonelastic material, for example a nonwoven.
[0029] It is of course also possible for the parts 11 and 13 to
have substantially the same extent in the circumferential direction
as the parts 10 and 12. In such a design, the connections 14 are
situated on the user's side and are thus slightly more difficult to
handle. However, such a design provides slightly better comfort for
the wearer and reduces the risk of chafing.
[0030] As will be seen from FIG. 3, the unit 7 also comprises leg
elastic having one or more elastic threads which can be arranged
between the cover sheets 2 and 3 and are secured to these, in the
stretched state, on both sides of the absorption body 1.
[0031] The liquid-permeable cover sheet 2 can be formed of, for
example, a nonwoven of spunbond polypropylene. Other materials
which are used for liquid-permeable cover sheets, so-called top
sheets, of absorbent articles, such as nonwovens of synthetic
and/or natural fibers, perforated plastic sheets or laminates of
such materials, can of course also be used as cover sheet 2.
[0032] The liquid-tight outer cover sheet 3 can be a plastic sheet,
preferably of the breathable type, or a laminate of a plastic sheet
and a nonwoven. All materials used as so-called backing sheets for
absorbent articles can be used.
[0033] The absorption body 1 preferably comprises a layer of
cellulose fibers with or without admixture of superabsorbents
and/or binder fibers. Other materials such as foamed material or
moss can also be used. The absorption body can also be made up of
several layers and advantageously comprises a layer of material
with high permeability, for example a wadding.
[0034] An embodiment of a method for production of diaper pants
according to FIG. 3 will now be described with reference to FIGS. 1
and 2. To simplify a comparison with the diaper pants in FIG. 3,
the components in FIGS. 1 and 2 have been given the same reference
numbers as corresponding components of the finished diaper pants in
FIG. 3. For example, the web of liquid-permeable material in FIGS.
1 and 2 has been given the same reference number as the cover sheet
2 of the finished diaper pants.
[0035] The diaper pants according to FIG. 3 can be produced in the
following way.
[0036] Absorption bodies 1 are placed on a running material web 2
of liquid-permeable material with the aid of a transfer wheel 17 on
which absorption bodies 1 formed in a mat former wheel (not shown)
have been deposited. If the absorption bodies 1 can be formed in
synchrony with the advance of the material web 2, the transfer
wheel can be omitted and the wheel 17 can be a mat former wheel.
The moulds of the mat former wheel are expediently designed such
that the absorption bodies leaving the mat former wheel have front
ends and rear ends directed toward each other. If this is not the
case, the transfer from the mat former wheel takes place in such a
way that every second absorption body is turned 180.degree. before
the absorption bodies are placed on the transfer wheel 17. The
absorption bodies 1 are then placed on the material web 2 in a row
with front portions and rear portions of adjacent absorption bodies
directed toward each other.
[0037] A material web 3 of liquid-tight material is then placed on
top of the row of absorption bodies 1. The material web 3 passes a
gluing unit 18 immediately before application and is secured, with
the aid of a pair of rollers 19, to the material web 2 in parts
lying outside the absorption bodies 1. If appropriate, the material
web 3 is also secured to the rear side of each absorption body 1.
Elastic threads or elastic bands 20 are inserted with the aid of a
feed unit (not shown) between the webs 2 and 3 and are secured to
these with the aid of the pair of rollers 19. Transverse elastic
elements, waist elastic, are also expediently applied between the
webs 2 and 3 before these pass through the pair of rollers 19. For
the sake of clarity, this elastic is not shown in the figures, as
it will be clear to the skilled person without illustration.
[0038] The combined web 1, 2, 3 of continuous diaper pants blanks
then runs through a unit 21 in which side panels 8, 9 are applied
to each diaper pants blank. In the embodiment shown, the side
panels 8, 9 are secured to the front portions 4 of the diaper pants
blanks, but they could equally well be secured to the rear portions
instead. The side panels 8, 9 of two adjacent diaper pants blanks
are contiguous with each other upon application and differ from the
side panels shown in FIG. 3 by being rectangular. Each side panel
8, 9 has two parts 10, 11 and 12, 13, respectively, which are
connected to each other by a connection 14 (not shown in FIGS. 1
and 2) which is described with reference to FIGS. 3 and 4. The unit
21 can be arranged in such a way that, on both sides of the web of
continuous diaper pants blanks, it can deliver and then secure
rectangular side panels 8, 9 from a store of these, or the unit can
also be arranged to separate rectangular side panels from a storage
roller and then deliver these and secure them to the web of
continuous diaper pants blanks. The side panels are attached by
adhesive bonding or welding, for example, and the unit 21 thus also
comprise, in the case of adhesive bonding, a gluing unit and a
stamp or the like and, in the case of welding, a welding device,
for example an ultrasonic welding device.
[0039] After application of the side panels, the web of continuous
diaper pants blanks runs through a cutter device 22 in which
individual diaper pants blanks are cut out. In the embodiment
shown, the cutter device is a blade roller which also cuts out leg
openings from the diaper pants blank. In the illustrated embodiment
of the diaper pants according to the invention, part of the leg
openings is included in the side panels 8, 9. It is of course
possible to cut out the leg openings in the web of continuous
diaper pants blanks before the application of side panels,
especially if the diaper pants are designed such that that part of
the side panels included in the leg openings can be straight.
Instead of rectangular side panels, it is of course also possible
to apply side panels which have leg recesses. However, this is not
preferred because it considerably increases the precision
requirements for application of the side panels. The leg recesses
are therefore preferably cut out after the side panels have been
secured to the web of continuous diaper pants blanks. In the
embodiment shown, the same blade roller is used for cutting leg
openings and for dividing the web of continuous diaper pants blanks
into individual diaper pants blanks, but it is of course instead
possible to cut the leg openings before division by using a
separate cutting device.
[0040] After the division of the web of continuous diaper pants
blanks, the individual diaper pants blanks are fed to a folding
device 23 via a guide arrangement (not shown), for example a guide
rail and a suction conveyor. In the embodiment shown, the device 23
comprises a pair of rollers 24 and a member 25 which executes a
reciprocating movement and which drives the crotch portion of the
diaper pants blank into the nip of the roller pair 24 when the
diaper pants blank is situated at the nip. In this way, the diaper
pants blank is folded double so that the front edge is situated
level with the rear edge.
[0041] To obtain finished diaper pants from the diaper pants
blanks, all that is left to do is to fold the side panels in across
the rear portion of the diaper pants blanks and secure the side
panels to these. It is simplest to secure the side panels to the
rear portion by gluing. Every second double-folded diaper pants
blank leaving the folding device 23 will have the front portion
uppermost, and every other one will have the rear portion
uppermost. This means that for every second double-folded diaper
pants blank, the glue will be applied from above along the edges of
the free ends of the side panels, and for every other diaper pants
blank the glue will be applied from below. For this purpose, two
gluing sprays 25, 26 are arranged for alternate use. Likewise,
every second pair of side panels 8, 9 are folded upward and every
other pair downward, and two devices 27, 28 are provided to
alternately fold the side panels in across the rear portions and
secure them to these. The devices 27, 28 can each comprise a pivot
arm or the like which, with the aid of a vacuum, takes hold of the
free ends of the side panels on their unglued side and then folds
the side panels in across the rear portions and presses the glued
side of the free ends of the side panels against the side areas of
the rear portions. The devices 27, 28 also comprise a movable
counterstay against which the pivot arms press. The diaper pants
blanks are expediently fed intermittently past the gluing sprays
25, 26 and the devices 27, 28 and leave the devices 27, 28 as
finished diaper pants.
[0042] The web 3 of liquid-tight material can be placed on top of
the web 2 of liquid-permeable material after the absorption bodies
have been placed thereon. It is of course possible to switch the
webs around so that absorption bodies are placed on the web of
liquid-tight material, and the web of liquid-permeable material is
applied last.
[0043] By virtue of the fact that the detachable and resealably
connected two-part side panels are applied to the web of continuous
diaper pants blanks in the sealed state, the precision requirements
when arranging the side panels on the web of continuous diaper
pants blanks are reduced compared to the situation if the parts of
the side panels were each to be applied individually, because a
deviation from the desired position of the side panels, for example
in the longitudinal direction, does not entail an offset of the
mutual positions of the parts included in the resealable
connection. In the event of such a deviation of a side panel whose
free end contains a male element which is intended to interact with
a female element secured to the outer cover of the diaper pants,
the male and female elements of the securing arrangement will be
offset in relation to each other. This means that the resistance to
opening of the connection is less than intended, the diaper pants
have a less attractive appearance, and the fit after opening and
resealing is not as good as intended, if one assumes that the male
and female elements after opening are joined together so that they
completely overlap each other.
[0044] The arrangement of the diaper pants blanks so that the front
and rear portions of adjacent diaper pants blanks are directed
toward each other also means that two side panels can be arranged
in one piece and then divided by a straight cut in connection with
the cutting of individual diaper pants blanks. This can ensure that
the waist edges of the side panels and the part of the diaper pants
containing the absorption body are always at the same level, which
can be difficult to achieve upon application of individual side
panels. It should be noted that, in a web of continuous diaper
pants blanks in which the front portions are directed in the same
sense so that the front portion of one diaper pants blank is
directed toward the rear portion of the nearest leading diaper
pants blank, very great precision is needed when dividing the web
into individual diaper pants blanks by means of straight cuts, so
as to ensure that part of the rear portion does not end up in the
front portion, or part of the front portion end up in the rear
portion. If the front and rear portions have the same width and the
same material composition, this has no great effect, but, if these
portions have a different width or different material composition,
it is important to ensure that the cut is made in exactly the right
place. By means of the methods described as embodiments of the
invention herein, the tolerances for the positioning of the side
panels are thereby increased, and at the same time the position of
the dividing cuts requires less precision compared to methods in
which a separate side panel for each front portion is applied.
[0045] In addition, the childproof connection can be made with
great care and precision since this is done in a production step
before the actual diaper production. It is thus possible to use
optimum web speeds, which can be considerably slower than the web
speeds normally pertaining in process lines for diaper production.
A number of parallel side panel blanks can be produced
simultaneously if the web width is great enough. In this way, a
large number of side panels can be prefabricated per unit of time
without the web speed being too high.
[0046] The described method can of course be modified within the
scope of the invention. For example, the side panels 8, 9 can be
applied to the material web 2 before the material web 3 is applied,
so that the side panels are arranged between the material webs 2
and 3 and are secured to both of these webs. The side panels can
also be secured to the liquid-permeable cover sheet. The absorption
bodies 1 can be completed with further layers, such layers being
applied on top of the bodies 1 by means of further transfer or mat
former wheels being added to the arrangement shown in FIGS. 1 and
2. Moreover, members for providing liquid barriers, so-called
standing gathers, can be added to the arrangement. The waist
elastic, which preferably extends along the front edge and rear
edge of the diaper pants, does not need to be arranged between the
material webs 2 and 3 and can instead be applied upon one of these
webs. The absorption bodies can have a shape other than that shown,
for example they can be rectangular or hourglass-shaped. Types of
securing elements other than VELCRO.TM. members can be used, for
example different types of snap-fit connections, which can also be
made childproof. It is also conceivable for the side panels to be
made up of two parts with the same dimension in the circumferential
direction. The components included in the arrangement described are
of a type generally used in production of diapers, diaper pants and
similar articles and can be replaced by other components with the
same function, for example the blade roller can be replaced with a
punch device. The invention is therefore limited only by the
content of the attached patent claims.
[0047] Although only preferred embodiments are specifically
illustrated and described herein, it will be appreciated that many
modifications and variations of the present invention are possible
in light of the above teachings and within the purview of the
appended claims without departing from the spirit and intended
scope of the invention.
* * * * *