Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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AN ELASTIC COMPOSITE, AND A SYSTEM AND METHOD FOR MAKING THE
ELASTIC COMPOSITE
BACKGROUND OF THE INVENTION
[00011 The present invention relates generally to elastic composites. More
particularly, the present invention relates to an elastic composite that can
be employed in one
or more areas of a garment, other textile or fabric structures, similar
material structures, and
the like. The present invention also relates to a system and method of making
the elastic
composite and a garment, other textile or fabric structures, and the like,
employing the elastic
component. The elastic composite and the system and method for making the
elastic
composite are particularly suited for use with or on disposable absorbent
garments or articles
such as baby diapers and training pants. To illustrate the invention,
exemplary and preferred
embodiments described in the context of disposable absorbent garments.
[00021 Pending United States patent application publications US2005/0131373A1
and US/2005/0139311A1 provide background information on elastic composites
(and the
manufacture of such composites) of the type relevant to the present invention.
Accordingly,
some portions of the publications have been included herein to facilitate
description of the
invention.
Additionally; these
publications provide samples of Processes for which the present invention
provides
improvements, particularly those intended to increase efficiency,
productivity, and/or
accuracy, among other things.
[00031 Disposable absorbent garments contemplated by the invention include'
disposable diapers, disposable pull-on garments, and the like. The principal
elements of a
typical disposable absorbent garment include a liquid permeable inner layer
(or topsheet), a
liquid imp.ermeablc outer layer (or backsheet), and an absorbent core
sandwiched between the
- inner and *outer layers. Elastic members may be incorporated into
different parts of the
garment. For example, elastic members may be positioned longitudinally along a
diaper,
generally outboard of the absorbent core to effect a seal around the buttocks,
legs, or both of
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the users. In addition, several elastic members (e.g., in the form of
elongated elastic threads
or strands) may be positioned laterally throughout the waist regions
(including the side waist
regions) of a disposable absorbent garment. The resulting elastication allows
the garment to
stretch when it is put on and then during wear. In this way, the garment can
stretch to
accommodate variations in waist size and leg size of the user, while fitting
snugly about the
waist and legs.
[0004] When elastic members are= incorporated into a part or area of the
garment, that
part or area typically becomes a distinct, functional Component of the
garment. These elastic
components include the side panels or ear portions, the waistband, and
fastening tabs. The
elastic components to which the present invention is directed is generally
elongated, and may
be a distinct portion of a larger, unitary piece, or a separate, attachable
component.
Furthermore, the elastic component typically contains one or more sections or
layers in
addition to the elastic members. In this regard, such an elastic component may
be referred to
as an elastic composite.
[0005] These elastic composites are typically functional components that have
an
= important impacton the fit and sealability of the garment. Due in part to
its multi-component
construction, these elastic composites typically require a dedicated sub-
process for
manufacture which must be accommodated by the larger garment manufacturing
process.
Alternatively, the elastic composite may be manufactured independently and fed
into the
larger process as a complete product. The design and construction of the'
elastic composite
represents, therefore, a significant portion of the cost of manufacturing a
disposable absorbent
garment, as well as the quality and utility of the finished product.
100061 It is; therefore, desirable to provide a functionally and/or an
aesthetically
improved= elastic composite, and an improved system and method of making the
elastic
composite. Furthermore, such an elastic composite, method, and/or system is
desired that can
. Provide improvements in productivity, efficiency, accuracy, and/or cost.
For example, cost
benefits (among other benefits) may be derived from such a system and/or
method that
increases the speed and output of elastic composites, or minimizes the space
and/or
component required for making the elastic composite (as compared to prior art
systems and
methods). Increases in speed or output may be achieved by increasing the speed
or rate of
one or more subprocesses, e.g., conveying, folding, feeding, or elastic
applying processes of
the larger manufacturing process.
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SUMMARY OF THE INVENTION
[0007] For purposes of the present description, the term "elastic band" or
"elastic
composite" refers to a multi-layer construction. In this construction, a
plurality of elastic -
members, such as threads or strands, are disposed adjacent one or more layers,
e.g., backsheet
and topsheet. In this way, the elastic members impart elasticity to the
adjacent layers and
thus, to that part of the garment or other textile structure. Such an elastic
structure may be a.
distinct attachable component of the garment or textile structure or may be a
distinct portion
or section of the garment body or textile structure or a larger, unitary
component of the
= garment body or textile
structure. =
[0008] In one aspect, a method of making an elastic composite for
incorporation into
a disposable absorbent garment, textile or fabric structure, and the like is
provided. The
method comprises the steps of: conveying a first web of material along a first
web plane
moving path; conveying a second web of material along a second web plane
moving path
generally =parallel with the first web plane moving direction; and applying a
section of a
continuous strand of elastic element onto both the first web and the second
web along a
direction generally transverse to the web plane moving paths.
[0009] In another aspect, another method of making an elastic composite is
provided.
The method comprises the steps of: conveying a first web, whereby the first
web moves along
a predefined path; applying a first section of a first elastic strand onto the
first web and
generally transversely to the moving web; applying a second section of a
second elastic
strand onto the first web and generally transversely to the moving web;
andrepeating the
applying steps while performing the conveying step, thereby arranging a
plurality of first and
second elastic elements on the first web, in generally parallel relation to
one another.
100101 The present application is also directed to systems-of making an
elastic
composite, suitable for employment with the above-described methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a plan view of a disposable absorbent garment in the unfolded
configuration; FIG. 2 is a plan view of an elastic composite;
[0012] FIG. 3 is a plan view of the elastic composite of FIG. 2 shown in an
extended,
stretchable condition;
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100131 FIG. 4 is a perspective view of the elastic composite of FIG. 2 with a
cut-out
detail to show an elastic construction;
[0014] FIG. 5 is a simplified schematic of a system for manufacturing the
elastic
composite according to the present invention;
[0015] FIG. 6 is a top view of an elastic element applicator assembly for use
with the =
system of FIG. 5;
[0016] FIG. 7 is a side view of the assembly of FIG. 6;
[0017] FIG. 8 is a simplified process illustration of making the elastic
composite
according to the invention; =
100181 FIG. 9 is a plan view of an alternative elastic composite according to
the
present invention;
[0019] FIG. 10 is a top view of an alternative elastic element applicator
assembly for
use with the system of FIG. 5, according to the invention; =
[0020] FIG. 11 is a simplified illustration of a folding guide assembly for
use with the
system and method according to the invention;
[0021] FIG. 12A is a perspective view of an elastic composite used for
reference;
[0022] FIG. 12B is a perspective view of an elastic composite, according to
one
embodiment of the present invention;
[0023] FIG. 13A is a perspective view of another elastic composite used for
reference; =
[0024] FIG..13B is a perspective view of an alternative elastic composite,
according
to another embodiment of the present invention;
[0025] FIG. 14A is a top view of a system for making an elastic composite,
according
to an embodiment of the present invention; =
=
[0026] FIG. 14B is.a side view of the system in FIG. 14A;
[0027] FIG. 15A is a top view of a system for.making an elastic composite,
according
to an alternative embodiment of the invention;
[0028] FIG. 15B is a side view of the system in FIG. 15X;
= [0029] FIG. 16A is a cross-sectional view through line AA in FIG. 14B;
[0030] FIG. 16B is a cross-sectional view through line BB in FIG: 14B;
[0031] FIG. 16C is a cross-sectional view through line CC in FIG. 19B;
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[0032] FIG. 16D is a cross-sectional view through a web output of elastic
composite,
according to the present invention;
[0033] FIG. 17 is a simplified flow chart illustrating basics steps of a
method of
making an elastic composite, according to the present invention;
=
5 [0034] FIG. 18 is a top view of a system for making an elastic
composite, according
to an embodiment of the present invention;
[0035] FIG. 19 is a perspective view of the system in FIG. 18;
[0036] FIG. 20A is a cross-sectional view through line AA in FIG. 18;
[0037] FIG. =20B is a cross-sectional view through line BB in FIG. 18;
[0038] FIG. 20C is a cross-sectional view through line CC in FIG. 18;
= [0039] FIG. 21 is a cross-sectional view of a web output of elastic
composite,
according to the present invention;
[0040] FIG. 22 is a simplified flow chart illustrating basic steps of a method
of
making an elastic composite, according to the present invention;
[0041] FIG. 23A is a perspective view of an elastic composite having dual
elasticized
regions; =
[0042] FIG. 23B is a perspective view of another elastic composite having dual
elasticized regions;
[0043] FIG. 23C is a perspective view of an elastic composite having dual
elasticized
= regions, according to another embodiment of the present invention; =
= [0044] FIG. 24A is a simplified .illustration and front view of an
alternative elastic
= element applicator in the form of a spinhead, according to the present
invention;
[0045] FIG. 24B is a simplified illustration and top view of a web substrate
conveyed
in a method of making an alternative elastic composite, according to the
present invention;
[0046] FIG. 25A is a simplified illustration and front view of an alternative
elastic
element applicator in the form of a spinhead, according to the present
invention;
[0047] FIG. 25B is a simplified illustration and top view of a web substrate
conveyed
in a method of making an alternative elastia composite, according to the
present invention:
DETAILED DESCRIPTION OF THE INVENTION
[0048] In FIG. 1, a disposable absorbent garment 110 is shown that is suitable
for the
invention and in the form of a diaper having one or more elastic composites
incorporated
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therein. The elastic composite in FIGS. 1-4 and FIG. 9 have side and end edges
and, thus,
may be referred to herein as elastic composite bands. FIG. 5 illustrates a
system and process
of making the elastic. composite (and a garment having the plastic composite)
in accordance
with a previously described concept.
[0049] FIGS. 12-15 and 24-25 are now provided to illustrate another method(s)
or
= process(es) of making an elastic composite (and a garment having the
elastic composite), and
a system for making or manufacturing the elastic composite, in accordance with
the present
invention. These figures also embody various aspects of the present invention
in the form a
novel elastic composite, a web output of the =elastic composite, and/or a
material structure,
such as a disposable absorbent garment, textile or fabric structure, similar
material structures, =
and the like, and into which the elastic composite is incorporated. The
described system and
process are particularly focused on the application or integration of the
elastic elements upon
or with one of the layers of the composite.
[0050] FIGS. 16-23 are also provided to illustrate yet another method(s) or
process(es) of making an elastic composite (and a garment having the elastic
composite), and
a system for making or manufacturing the elastic composite, in accordance with
an
alternative embodiment of the present invention. These 'figures also embody
various aspects
of the present invention in the form a novel elastic composite, a web output
of the elastic
composite, and/or a material structure, such as a disposable absorbent
garment, textile Or
fabric' structure, and he like, into which the elastic composite is
incorporated. The described
system and process are particularly focused on the application or integration
of the elastic
= elements upon or with one of the layers of the composite.
= [0051] As described previously, various aspects of the present invention
are
particularly suited to or for a disposable absorbent garment, such as baby
diapers and training =
pants. To illustrate the invention and preferred embodiments of the invention,
much of the
following Detail Description will be provided in the context of such
disposable absorbent
garments. It is contemplated that various aspects of the inventive composite,
garment,
system, and process may be applicable to other material structures and
processes.. This
Detailed Description and exemplary embodiment should not, therefore, be
construed as
limiting the invention to the structures, configurations, methods, and
processes described
herein.
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[0052] The disposable absorbent garment 110 in FIG. 1 is of a type that can be
placed
against or in proximity to the body of a wearer so as to absorb and to contain
various bodily
exudates. It should be noted, however, that the present invention is
applicable to a variety of
disposable absorbent articles and garments, including training pants and a
variety of adult
incontinence products. As will be described below, the inventive elastic
composite or elastic
composite band may provide a side panel or ear portion, a waistband; a
fastening tab or band, .
or other distinct elastic component of the garment or article. The inventive
elastic 'composite
may also be incorporated into an ear portion to elasticate the ear portion or
to supplement the
=
ear portion with an elasticated fasteninglab. Accordingly, the present
invention is not
=
intended to be limited to the structures and the processes specifically
described and illustrated
herein. For purposes of description, however,.the following discussion will be
directed to an
exemplary disposable diaper only. Moreover, the invention will be described in
the context
of its various configurations and aspects. It should be appreciated that
alternative
arrangements of the inventive disposable absorbent garment and such an elastic
composite
band may comprise various combinations, which include one or more of the
various
configurations and aspects of the invention.
[0053] FIG. 1 is introduced to illustrate some basic features of a disposable
diaper
110, most of which are also applicable to other disposable absorbent garments
contemplated
by the invention. The diaper 110 includes three main regions aligned along an
imaginary
longitudinal axis or plane AA. These regions include a first waist region 112
(typically at the
front of the user when the garment 110 is worn), a back waist region 114, and
a crotch region
116. The diaper 110 is also characterized by a front edge 140, a back
longitudinal edge 142,
a first lateral or side edge or side margin 144, and a second lateral or side
edge or side margin
146.
[0054] Along a lateral direction, the diaper 110 includes ear regions or ear
portions
118 extending laterally from the waist regions 112, 114. Together, the waist
regions 112, 114
and crotch region 116 may bereferred to as forming a central body portion 120
of the
garment 110 that is positioned within side edges 144, 146. The body portion
120 may also be
referred to as being formed by a liquid permeable inner layer .or topsheet
152, a liquid
impermeable outer layer or backsheet (not shown), and an absorbent core 154
sandwiched =
= between the two layers. The ear portions 118 further include fastening
tabs 124 for attaching
the waist regions 112, 114 together. The diaper 110 also has an elastic
waistband 130
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positioned generally along the back edge 142 to facilitate fastening and to
enhance the fit and
seal of the diaper 110. When the hourglass shaped diaper 110 is worn, the
crotch region 116
fits about the crotch of the wearer, and the front and back waist regions, 112
and 114, fit
about the corresponding waist areas. The ear portions 118, on the other hand,
wrap about the
. 5 wearer and the fastening tabs 124 engage to form a complete, all-
around waistline of the
diaper 110.
[00551 FIG. 2 depicts a typical elastic composite band 210. More particularly,
the =
elastic composite band 210 is one particularly suited for use as a side panel
or fastening tab of
a disposable absorbent garment (see, e.g., Fig. 1). FIG. 4 provides a
perspective view and
partial cut-out of the elastic composite band 210. The elastic composite band
210 may be
= characterized by an imaginary centerline LL. In one aspect of the
invention, the centerline
LL preferably corresponds with the machine direction of the elastic composite
band 210
during manufacture. The elastic 14tid 210 also has side or longitudinally
extending side
edges 210a and 210b and laterally extending end edges 210c and 210d. In FIG.
1, the elastic
composite band 210 is shown in the stretched state as, for example, when a
garment
incorporating the elastic composite band 210 is worn. In this state, the
elastic composite
band 210 stretches, in the lateral or cross-machine direction (denoted by
arrows XX).
[00561 As used herein,-the term "machine" direction refers to the direction at
which
the component, or more particularly, the material web from which the elastic
composite is
derived (e.g., cut from) is driven in an assembly line during manufacturing.
The term "cross-
directional machine direction" or "cross-directional," on the other hand,
refers to the direction
that is perpendicular to the machine direction. With reference to the elastic
composite 20 of
.FIG. 2, the cross machine direction is the direction XX extending laterally
or perpendicularly
=
relative to the longitudinal line LL. =
[0057] The elastic composite band 210 has a central region 214 in which an
elastic
. construction is situated. Extending laterally from this central elastic or
elasticized region 214
are regions 216 and 21.8, which are substantially non-elasticized. As shown in
FIG. 2, the
regions 216, 218 occupy the expanse between the central .elastic region 214
and the side
edges 210a, 210b. Now with reference to FIG. 4, the elastiC composite band 210
has a top
layer 318 and a bottom or base layer 320. The two layers 318, 320 preferably
extend the total
width and length of the elastic composite band 210, thereby providing the side
edges 210a, .
210b, and the end edges 210c, 210d.. Both the base layer 320 and the top layer
318 are
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preferably non-woven, breathable, disposable materials such as propylene, non-
woven fabric,
breathable polyethylene/polypropylene films, or non-porous films (or
combinations of these
materials): The base layer 320 and top layer 318 adhere to one another,
thereby sandwiching
and securing a plurality of elastic strands 322 therebetween.
[0058] The elastic strands 322 may be substituted, in alternative
.embodiments, by
suitable elastic elements such as elastic strands, threads, ribbons, and
elastic glue beads. In
one aspect of the invention, the elastic elements or strands 322 are
distributed along a
direction that extend between the side edges 210a, 210b and parallel with (or
corresponding
to) center line LL. Further, each elastic element 322 is generally aligned or
oriented in a
direction corresponding with the lateral or cross-machine direction, i.e., in
a direction
= generally perpendicular to the longitudinal center line LL and
intersecting the side edges
210a, 210b. Preferably, the strands 322 are disposed in generally parallel
relation and spaced= =
apart generally equally along the longitudinal direction. More preferably,=
the elastic strands
322 are of generally equal length. Accordingly, when the elastic composite
band 210 is
worn, the strands 322 impart elasticity. into the structure which alloWs the
band 210 to stretch
in the lateral or cross-machine direction XX.
[0059] The elastic strands 322 are preferably tensioned during securement
between
the top and base layers 318, 320. FIG. 3 illustrates the elastic composite
band 210 in a
laterally stretched condition. In this condition, the central elastic region
214 has a width that
is almost equal to the non-elasticized zones 216 and 218. When returned to the
non-laterally
stretched or relaxed condition, as shown in FIG. 2, the central elastic region
214 contracts and
= crimps to a substantially reduced width. In this condition or state, the
contracted elastic
strands 322 shirrs the elastic composite 210 and provide pleats 234 in the
contracted elastic
region 214.
= [0060] Returning to FIG. 1, the disposable absorbent garment 110 employs
one or
more elastic composite bands. The disposable absorbent garment 110 employs in
each of the
=
ear portions 118, a fastening tab 124 having the elastic composite
construction. As the =
fastening tab 124, the elastic composite band is configured such that one non-
elasticized
region 124a is attached to and overlaps the central body 120 of the garment
110 while a
secong non-elasticized region 124b is situated outboard of the side margins
144, 146. An
elasticized region 124c, as shown in FIG. 1, provides elasticity, and thus,
stretch in the lateral
or cross-machine direction (of the elastic composite). In respect to the rest
of the garment
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110, the elasticity or stretch provided by the central elastic region 124c
directed along a
direction that is generally perpendicular to the longitudinal center line AA
of the garment
110, and corresponds with a direction that wraps about the waistline of the
user.
[0061] The disposable absorbent garment 110 in FIG. 1 also provides an elastic
5 composite, as the waistband 130. The waistband 130 is situated centrally
in the waist region
114. Further, the elastic composite waistband 130 is disposed such that non-
elasticized
regions 130a, 130b are positioned outwardly of the longitudinal line AA of the
garment 110,
while an elasticized region 130c i positioned centrally across the
longitudinal center line
AA. Moreover, the elasticized region 130c is configured such that the elastic
strands are
, 10 aligned or.oriented in a direction that is generally perpendicular
to the longitudinal center line
AA. In this way, the elastic composite waistband 130 imparts elasticity about
the waist
region 114 of the garment 110, and in a direction corresponding with the
direction of
waistline about the user.
. [0062] FIG. 9 depicts an alternative elastic composite band. The
elastic composite
band 710 illustrated therein differs from the previously described elastic
composite band (see
e.g. FIGS. 2 and 2a) in that the elastic composite band 710 includes two
elasticized regions
714a and 714b. The elasticized region 714a, 714b are preferably equidistantly
spaced apart
on either side of the longitudinal centerline AA. The spacing of the
elasticized regions 714a,
714b creates right and left non-elasticized or dead regions 716, 718, as well
as central non-
elasticized region 750. The elasticized regions 714a, 714b imparts elasticity
to elastic
composite band 710a in the lateral directions XX, and in the central non-
elasticized region
750, also in the opposite lateral direction VV.
[0063] FIGS. 5-8 and 10-11 depict a system and system components, and
illustrate a
method or process of making or manufacturing-the elastic composite. Two
elastic composite
web outputs 1031 are produced from four separate non-woven web inputs 1003a,
1003b,
1003c, and 1003d. To facilitate the description, reference may be made to U.S.
Patent Nos.
3,627,621 and 2,902,395, each of which discloses certain features of the prior
art system and
process for manufacturing a lamination and/or composite having non-woven
materials.
In particular, reference may be made to certain basic components of a system
or apparatus for
manipulating non-woven materials and fibers.
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[00641 Referring first to FIG. 5, a system 1001, includes four separate non-
woven
web inputs 1003a-1003d, which provide a web or roll of non-woven material for
the elastic
composite. The system further includes an output assembly or reel 1005 that
receives twb
elastic composite webs 1031 from the rest of the process. These two separate
elastic webs
may be fixed together to produce the kind of composite described in respect to
FIG. 4 (or
maintained separately). =
[00651 Central to the system 1001 are a conveyor assembly 1009 for receiving,
manipulating, and conveying each of the non-woven web inputs. The conveyor
assembly =
1009 is positioned and operatively associated with an elastic element
applicator such as a
.10 spinning head assembly 1007, that applies elastic fibers or strands
upon, onto, and or
integrally with the non-woven -Web inputs. The spinning head assembly 1007
further includes
a spin head 1017, preferably in the form of a spinning bracket, or cylinder
1017 and the like.
The spin cylinder 1017 is configured to hold an "end section" of the
continuous strand WW
of elastic and move it about a generally vertical plane XX in a reciprocal or
repetitive pattern
(relative to the conveyor assembly 1009). This plane XX is defined by the area
within the
spinning perimeter of the cylinder 1017 and which is traced by the outer most
bracket or eye
1017b securing the strand of elastic WW to the spin cylinder 1017. The paths
of the spinning
. head 1017 and the section of elastic strand retained thereby are provided on
the plane XX.
[0066]=As shown in the schematic of FIG. 5, nonwoven inputs 1003a and 1003b
are
fed, utilizing a series of rollers, into the conveyor assembly 1009. Before
the two nonwoven
webs are fed into the conveyor assembly 1009, the webs are directed through
the folding -
guides or plates 1039. The folding guides 1039 serve to effectively reduce the
overall width
of the nonwoven web by folding the lateral or side edges along a pre-
determined,
longitudinally-extending side fold line YY. = The first folding guide 1039a
initiates the first
90 turn while the second folding guide 1039b initiates a second 90 turn. The
roller 1039
disposed in between the guide 1039a, 1039b facilitates the folding process.
The two folding
guides 1039 and roller 1369 may be referred together as a folding guide
assembly.
[0067] FIG. 11 illustrates yet another typical folding guide assembly. The
folding
assembly 1639 includes folding plates 1639a and a roller 1669 upstream of the
folding plates
1639. *A web 1603 is passed around the narrow roller 1669, whereby the width
of roller 1669
helps determine the width of the web 1603 between the folded flaps VV (i.e.,
the width of
exposed outward surface 1689 defined between the fold lines YY). The width of
the roller
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1669 is substantially less than the width of the nonwoven web 1603. As a
result, the edges of
the nonwoven web 1603 list and curl up around the sides of the roller 1669,
thereby initiating
the folding process. The flat plates 1639a then helps to complete the fold and
hold the folded
sides down. Another folding guide (not shown) may be.provided in a position
upstream of
the folding roller 1669 to help guide or initiate the.folding process.
[0068] For purposed of the present Description, the inward surface 1679 is the
surface
or side of the web 1603 toward which the folded flaps VV are turned. The
exposedoutward
surface 1689 is the surface opposite of the inward surface =1679.
[0069] The conveyor assembly 1009 is set up so as to guide these two nonwoven
webs 1003a and 1003b through the center of the assembly 1009 towards and
eventually
inside the elastic spin Cylinder 1007 (into the spinning path). Once inside
the spin cylinder
1017 the conveyor assembly 1009=delivers the nonwoven webs to each outside,
upper and =
lower faces (outward faces) of the conveyor assembly 1009. At this point the
direction of
travel of the nonwoven webs are reversed and the webs are directed out of the
spin cylinder
1007. As the nonwoven webs exit the spin cylinder 1017, an elastic strand WW
is wrapped
around the entire conveyor assembly 1009, and as it contacts the upper and
lower face of the
web platforms it comes into contact with:the nonwoven web. As shown in several
of the
Figures, the elastic strand WW is applied crosswise or laterally on the web,
and transverse to
the direction of the moving web. The friction between the tensioned=elastic
strand and the
nonwoven webs on the upper and lower faces of the conveyor assembly draws=the
"wrapped"
elastic strand out of the spin cylinder 1017 and towards contact with two
further nonwoven
webs 1003c and 1003d.
[00701 The nonwoven webs 1003c and 1003d are operatively positioned upstream
of
an adhesive applicator 1013. Utilizing a system of rollers in conjunction
therewith, the non-
.25 woven inputs 1003c, 1003d and adhesive applicators 1013 apply a web of
pre-glued non-
woven material onto the conveyor assembly 1009 and onto the elastic strand
"wrapped" '
around the nonwoven webs 1003a and I003b. =
[0071] Furthermore, the system 1001 employs a standard elastic input source
1011, e.g., a
bobbin of elastic yarn, that feeds elastic strands or fiberS WW onto a
tensioning/speed
controlling unit 1037 and then to the spin cylinder or the spinning head 1017,
so as to apply
the strands WW onto the conveyor assembly 1009 and the non-woven material webs
conveyed therethrough. Elastic is taken off the bobbin, box or positive drive
system and fed
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through a tension and speed controlling motor towards the spin cylinder 1017.
The elastic
WW is delivered through a hollow shaft in the motor controlling the spin
cylinder 1017. The
elastic WW then passes into the spin cylinder 1017 and is guided by rollers,
eyes= or any other
suitable Mechanism around the inside face of the spin cylinder 1017.
[0072] FIGS. 6 and 7 provide alternate views of the spinning head assembly
1007 and
conveyor assembly 1009. As discussed above, the conveyor assembly 1009
receives four
separate webs of non-woven materials and outputs two webs 1031 of elastic
composite.
FIGS. 8 and 9 are provided to further illustrate the process= of making the
elastic composite.
These figures, more particularly FIG. 8, illustrates the paths taken by the
non-woven web
materials to and from the conveyor assembly 1009.
[0073] Referring to FIG. 8, reference letters A-G are used to refer to stages
in the
process and in conjunction with the description of the process. As discussed
above,.non-
woven raw material webs are fed into the process at stage A. These webs
provide four
separate non-woven web inputs into the process. Non-woven webs 1 and 3 are
combined to
make an elastic composite output 1 (i.e., referred to in the Figures as the
WRAP output).
Non-wovens 2 and 4, which are both on the downside of the spinning head
assembly 1007
and conveyor assembly 1009, combine to make a second elastic composite output
2 (Le.,
WRAP
= [0074] At stage B, non-woven webs 1 and 2 are folded prior to being
directed to the
conveyor assembly 1009. A predetermined width of non-woven is folded= over
each side of
the web to make two folded flaps VV. The width of the flap VV determines the
width of the
dead zone or non-elasticized region described previously, while the width of
the non-woven,
after folding, determines the width of the elasticized region. At stage C, the
non-woven webs
1 and 2 are fed into the conveyor assembly 1009, in particular into the middle
or inside of the
conveyor assembly 1009 with the folded side of each web facing the outside of
or away from
the conveyor assembly .1009. It should be noted that at this stage C, non-
woven webs 1 and 2
are not bonded together. The conveyor 1009 then feeds the non-woven webs 1 and
2 towards
the spinning head assembly 1007. At stage D, the non-woven webs 1 and 2 have
traveled =
almost the length of the conveYor assembly 1009 and progresses into the
spinning path of
spinning head assembly 1007 and intersecting the "spinning" vertical plane XX
of the elastic
strand WW. Further, at the end of the conveyor assembly 1005, the webs 1 and 2
are directed
away from each other and onto the outside of the conveyor 1009 and away from
the spinning
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14
head 1007. Non-woven web 1 turns up on the upper side of the conveyor assembly
1009,
while non-woven web 2 travels along the lower side of the conveyor.assembly
1009. At
stage E, an elastic strand WW is wound around the folded non-woven webs 1 and
2, as these
webs pass through the spinning head and the vertical plane XX. The elastic
strand WW is
applied to the moving webs 1 and 2 cross-directionally to the direction of the
moving web.
The movements of the webs 1 and 2 away from within the spin cylinder 1017
draws the
"wrapped" elastic strand out of the spin cylinder 1017.
[0075] Now turning to non-woven webs 3 and 4, these webs are provided to the
conveyor assembly 1009 with adhesive applied on one side (i.e., applied by the
adhesive
applicator 1013). At stage F, the non-woven webs 3 and 4 are brought into
contact with webs
1 and 2, respectively, and the elastic strands WW. As a result, the webs 1 and
3 sandwich
elastic strands WW on the upper side of the conveyor assembly 1009, and non-
woven webs 2
and 4 sandwich elastic strands WW on the under side of the conveyor assembly
1009. The
elastic strands WW run between the two non-woven elastic non-woven composite
(cross-
= direction), but is then cut by a knife (see knife 1410 in FIG. 9, as
described below), :thereby
separating the. twowrapped composites. At stage G, the composites 1 and 2 are
fed away
from the conveyor assembly 1009 and the folded flaps on webs 1 and 2 become
unfolded,
with guiding, to form a flat non-woven cOmposite. Subsequently, the composites
are guided
from the spinning head assembly 1007 and conveyor assembly 1009 and into
further
processes. As shown in FIG. 5, the elasticbutput webs arrives via a system of
rollers onto an =
elastic composite =output reel 1005.
[0076] As shown in FIG. 6, the conveyor assembly 1009 preferably includes two
web
moving platforms 1412 which are juxtapositioned so as to provide an interface
therebetvveen.
Each web moving platform 1412 includes a continuous belt 1.414 supported about
a plurality
of rollers 1416 so as to be capable of reciprocal motion. The two web moving
platforms
1412 are generally the same length and juxtapositioned sO as to accommodate
the non-woven
webs 1 and 2 therealong from one end to the other end. Preferably, a roller
1416 is situated
about midway between the ends of the web moving platform so as to deliver the
non-woven
webs 3 and 4 respectively to the web moving platform. =
[0077] As shown in FIGS. 5, the spinning head assembly 1007 is positioned
about
and in the vicinity of one end of the conveyor assembly 1009. =In operation,
the spinning
head 1017 spins about the vertical plane XX which intersects the ends of the
web moving
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platforms 1412 so as. to deliver the elastic strands WW around and about both
web moving
platforms 1412. In operation, the first and second non-woven move along the
outside or
exposed.surfaces or sides of the web moving platforms 1412 and receives the
elastic strands
= WW delivered by the spinning head 1017. By way of its movement away from
the spinning
head 1017, the moving web draws the continuous elastic strand WW from the
spinning head
1017.
= = [0078] By pre-folding the two non-woven webs that are fed to the inside
of the
= conveyor assembly 1009,. it is possible to create an elastic composite
with cross directional
stretch having non-elasticized regions ("dead zones") along each edge. The
width of the
central elasticized region is fixed to the width of the conveyor platform
1412. The width of
the non-elasticized regions or dead zones is determined by the width of the
fold VV. The
fold VV in the non-woven is preserved by the conveyor assembly 1009 =during
application of
the elastic element and is applied in such a way that the folded edge of the
non-woven is not
in contact with the elastic element WW. The fold VV is then allowed to open
after the
composite exits the conveyor assembly 1009 to provide a flat elastic composite
with non-
elasticized regions. By altering the alignment of the materials as it enters
the conveyor
assembly 1009 or by changing the widths of the materials used it is possible
to create vadous
composite designs.
[0079] The above-described process provides an elastic composite=with cross
directional stretch properties. The process also provides non-elasticized
regions on either
latitudinal side of the central elasticized zone of the composite. For the
purposes of the
description the term "non-woven" is used to describe the principal material
used in the
construction of the elastic composite. However, it should be noted that this
invention is'not
limited to non-woven materials but may be applied to any material that is
available in the
form of a. continuous sheet. Other materials suitable for this application
include PE film, PE
= film/non-woven laminates and tissue.
[0080] FIG. 10 illustrates an alternative conveyor assembly 1509 and an
alternative
elastic element applicator in the form of a spinning head assembly 1507. As
will be =
understood by one skilled in the art, the spinning head assembly 1507 is
operated to convey .
or transmit elastic strands onto a web moving platforin 1512 of the conveyor
assembly 1509.
= As before, the conveyor assembly 1509 preferably employs two web moving
platforms 1512,
=
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16
- which are juxtapositioned so as to provide an interface therebetween. The
conveyor
assembly 1509 is similar to that illustrated in FIGS. 5 .and 6.
00811 On the other hand, the conveyor assembly 1509 is operated differently in
that
more than one elastic strand WW is applied onto and about the web moving
platforms 1512
= at one time. The spinning head assembly 1507 includes a spinning head in the
form of a spin =
bracket 1517 having a plurality of arms 1517a. The spin bracket 1517 receives
elastic strands
1553 from a shaft 1551a of a motor 1551. The motor 1551 feeds the two lines of
elastic
strands 1553 to the spin bracket 1517, and the two feeds of elastic strands
1553 are guided
together through the spinning head assembly 1517 (where the two lines twist
together). As
shown in FIG. 10, the two strands 1533 are moved about a y vertical plane then
delivered,
together, onto a nonwoven web 1544 moving horizontally on the web moving
platform 1512.
Preferably, both lines of elastic strand 1553 are fed onto the same arm 1517a
of the spinning
bracket assembly 1517 (rather than on opposite sides). In this way, the
separate feeds or lines
of elastic strands 1553 are prevented from twisting, together and possibly
breaking.
100821 By applying two lines (or more) of elastic strands onto the moving
nonwoven
web, the speed of the manufacturing process is increased. Specifically, the
speed at which
the composite is manufactured may be increased by up to 100%, without
increasing the speed
at which the spinning head assembly is spinning and without changing the
overall number of
elastic strands in the final composite. Table 1 below provides two examples of
the result of a
process of applying the elastic strands WW onto a nonwoven web. The spinning
head
assembly 1507 operates at the sarne rotational= speed in both processes.
However, the pitch
(i.e., the separation between elastic strands WW) is doubled for the
alternative process
(wherein a pair of elastic strands are applied to the nonwoven web). By
employing the
= alternative process, the total machine output is also doubled (i.e., from
40m/min of composite
to 80m/min). In both examples, the overall amount or length of elastic strands
WW utilized
or applied to the composite is generally the same. Consequently, the final
composite
=
produced by both subprocesses have the same, or at least, similar tensile
characteristics.
Table 1
Spin head Pitch (elastic No of elastic strands fed Total
machine output
speed = separation) into spin bead (two webs of
composite)
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8,000 rpm 2.5 mm = 1 40 rn/min
=
8,000 rpm 5 mm 2 80 m/rnin
=
[0083] It will be apparent to one skilled in the relevant art, upon reading
the present
description and/or reviewing the accompanying drawings, that the alternative
subprocess
described above may be modified to feed or apply a different munber of elastic
strands onto
the nonwoven web. That is, three or more elastic strands may be fed through
the spinning
head assembly .and applied to the nonwoven web.
[0084] Moreover, it is contemplated that the elastic strands may be separated
lnside
the spin head and directed independently to opposite sides of the nonwoven
web. In such a
=
case, it is preferred that the assembly 1507 that includes the elastic
bobbins/reel and
tensioners and guides the elastic strands into the motor 1551 (or more
appropriately, the
motor shaft 1551a), is rotated at the same speed and in the same direction as
the spin head
1517. In this way, the risk of twisting of the strands together inside the
.spin head 1517 is
minimized.
=
[0085] FIGS. 12A-14B are provided to illustrate aspects and embodiments of a
present invention. In particular, FIGS. 12B and 13B depict alternative elastic
composites
according to the invention. FIGS. 14A and 14B illustrate an exemplary system
that is
operable to implement a method of making the elastic composite also according
to the
invention. The exemplary system may be used with or integrated into the
system(s)
previously described in respect, for example, to FIG. 5. The invention, and
its various
aspects and embodiments, shall be'understood in view of FIGS. 12A-14B and/or
the
=
accompanying descriptions, as well as the previous illustrations and
accompanying
descriptions.
[0086] These additional Figures are provided for illustration and to
facilitate a
description the present invention. The present invention shall not, therefore,
be limited to the
structures and processes specifically described *and illustrated in respect to
FIGS. 12A-14B.
FIGS. 1-11, and accompanying descriptions, demonstrate application of a
tensioned elastic
strand across a moving web of nonwoven sheet. The elastic strand was affixed
to the
nonwoven sheet so as to provide a composite.having, among other attributes,
cross-
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directional elasticity. In respect to previous illustrations, the elastic
strand, or a group of
elastic strands, were fed via a single path and then applied to a moving web
of nonwoven
sheet by operation of a spin head. The elastic strand or group of elastic
strands are distributed
onto the web at the rate of one strand per single revolution of spinhead.
100871 In a further aspect of the invention, a method is now described whereby
multiple strands, e.g., two strands or two separate group of strands, are
applied to a moving
web of nonwoven sheet. Preferably, the.strands or collection of strands travel
by two =
separate paths and are distributed onto the web of nonwoven sheet at the rate
of two strands
per single revolution of the spinhead. The two strands may be applied
simultaneously to.
different portions of a conyeyor assembly conveying one or more webs. This
variation of the
invention provides advantages in efficiency as the output of the machine is
increased by at
least 100%. Alternatively; the machine speed may be reduced by as much as 50%,
providing
a reduction in running costs due to wear and tear and energy consumption. The
present
inventive method maintains, however, the same output and volume as the single
path
processes previously described.
100881 The following terms are used to describe certainsystem(s) and
process(es) for
making an elastic composite. In particular, these terms describe different
running
configurations.asSociated with this alternative method of manufacturing an
elastic composite.
First, the term "single strand, single path method (SSSP)" refers to a method
of manufacture
whereby one strand of elastic element is delivered to a web of nonwoven sheet
at the rate of
one strand per single revolution of the spinhead and via a single path Or mode
of travel
through the spinhead. This method was previously described in respect, for
example, to FIG.
13. Second, the term "multiple strands, single path method (MSSP)" refers to a
method of
manufacture whereby multiple strands of elastic element are grouped together
and distributed
via a single path or mode of travel through the spinhead. In this method, the
elastic strands
are distributed on the web of nonwoven sheet at the rate of one collection of
strands per
revolution of the spinhead. An.example of this method was described in respect
to FIG. 15.
= 100891 Furthermore, the term "single strand, dual path method (SSDP)"
refers to a
method of manufacture whereby two strands of elastic element enters the
spinhead and are
distributed onto the web of nonwoven sheet via two separate paths or modes of
travel, in
accordance with the present invention. In this method, the elastic elements
are distributed on
the moving web of nonwoven sheet at the rate of two strands per revolution of
the spinhead.
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The term "multiple strands, dual path method (MSDP)" refers to a method of
manufacture
whereby two sets of more than one strand are collectively grouped and are
distributed on the
web via two separate paths or modes of travel through the spinhead. .In this
method, the
elastic elements are distributed at the rate of two collections of strands per
revolution of the
spinhead.
[0090] As used hereafter, a substantially long feed of elastic may be referred
to as a
"continuous strand" even though it is understood that the strand is not
infinitely long.
Relative to the dimensions .of the elastic elements arranged on the elastic
composite, the
elastic strand is, for practical purposes, continuous. For present purposes,
the term
"continuous", as applied to "strand", shall indicate a length that will not be
consumed in less
= than a few revolutions of the spinlicad. Moreover, the term "strand" is
used to refer to the
feed or continuous length of elastic whereas the section or segments applied
to the elastic
composite may be referred to as "elastic elements." A "section" of elastic is
referred to
herein as the length (i.e., the end length) outside of, fed by, the arms or
eyelets of the
spinhead and is spun by the spinhead.
[0091] FIG. 12A reproduces, in an alternative view, the elastic composite 210
=
depicted in FIGS. 2A, 2B, and 3. Although shown in the stretch state, the
elastic composite
210 =has a fixed width DD in the lateral direction and apredetermined cut
length EE along the
longitudinal direction. During the manufacturing process, a continuous web-of
the elastic
composite 210 is delivered as output, having continuous longitudinally
directed side edges
210a, 210b and a central elasticized region 214 in which an elastic
construction is situated.
= Extending laterally from the elasticized region 214 are non-elasticized
regions 216 and 218
(also referred to herein as "dead zones"). The elastic composite 210 includes
a top layer 218,
a bottom layer 220, and a plurality of elastic elements 322 sandwiched
therebetween. The
top and bottom layers 218, 220 provided in most, if not all, of the examples
in these
descriptions are preferably nonwoven. It is contemplated, however, that other
materials may
also be used, including a variety of textile materials, fabrics, and the like.
=
[0092] As previously described in detail, the elastic element 322 extends
generally
along a direction generally perpendicular to the longitudinal or machine
direction and are
= spaced apart from one another by a generally fixed distance n or pitch. The
pitch n is directly
related to the manufacturing process settings and may be calculated as
follows: =
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n (mm) = (speed of conveyor (m/min))
(rotational speed of spinhead (rpm))
[0093] FIG. 12B depicts an exemplary sheet of elastic composite 1710 according
to
5 the present the invention. The elastic composite 1710 has been
manufactured in accordance
with a single strand dual path method. The elastic composite 1710 includes
sections and
components that are identical to those of the elastic composite 210 in FIG.
17A, with the
exception of a central elasticized region 1714: Sandwiched between a top layer
1718 and a
bottom layer 1720 are a plurality of spaced-apart, laterally extending elastic
elements 1722.
10 In this embodiment, the distribution of elastic elements 1722 is
alternately provided by a first
elastic element 1722a and a second elastic element 1722b. The first and second
elastic
. elements 1722a, 1722b differ in that one is fed from a source different
from the source of the
other. As will be further explained below, the sources are preferably a first
continuous elastic
strand and a second distinct, continuous, elastic strand. Typically, the two
continuous elastic
15 strands are of the same material type and have the same material
properties, but may be
varied, in further embodiments, to impart specifically targeted elastic
properties to the elastic
composite 1710. The two elastic strands may also differ in thickness (see
e.g., FIG. 29B as
described below), as well as or in lieu of varying elasticity. One of the
elastic strands may
even be a type of activated elastomer (e.g., heat activated). Further, the two
elastic strands
20 may have a different color to achieve a specific aesthetic design, for
example. Thus, the
method according to the present invention provides some flexibility in the
functional and
aesthetic design of the elastic composite.
[00941 The elasticized region 1714 includes an arrangement consisting of
alternating
first and second elements 1722a, 1722b that are spaced apart by a generally
fixed distance or
pitch n'. This pitch n' is reduced from the pitch n in the previous elastic
composite 210 (See
FIG. 17A), thereby providing for a.greater elastic density across the
elasticized region 1714.
As will be further described below, the two elastic elements 1722a, 1722b are
distributed
onto the web or nonwoven substrate preferably from opposing sides of the
spinhead. =For
every revolution of the spinhead, two strands of elastic elements 1722a, 1722b
are delivered
onto the web. Employing an MSDP method, the value of n' may be calculated one
half of
that obtained by the SSSP method (assn. ming that the speed of the nonwoven
conveyor:and
spinhead are maintained at the same speed as before):
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n' (mm) = (speed of conveyor (m/min))
2 x (rotational speed of spinhead (rpm))
[0095] In an alternative embodiment, two elastic strands are distributed from
the
spinhead at locations less than 180 apart (phase separation in one spin
revolution), as shown
in FIG. 24A, for example. In this way, the pitch between elastic elements may
be varied.
FIG. 24B depicts an exemplary web substrate 2960 whereon a plurality of first
elastic
.
elements 2922a and second elastic elements 2922b are applied on a moving first
input web
=
Wl. =The distribution of elastic elements provides an alternating sequence of
first elastic
.
element¨second elastic element ¨ first elastic element on the web substrate
2960. The first
and second elastic elements 2922a, 2922b are provided by, and are discrete,
severed portions
of, different elastic strands. In this example, the first elastic element
2922a has a greater
thickness than the second elastic element 2922b. Moreover, the distribution of
elastic
elements provides for different or alternating pitch between successive
elastic elements in the
sequence. The elastic elements 2922a, 2922b are alternately separated by a
pitch of n1 and a
pitch of n2. In this depicted example, the larger pitch n2 is three times
greater than the pitch
nl. As will be further explained below, this alternating pitch sequence may be
achieved by
providing a spinhead 2917 such as the spinhead 2917 illustrated in FIG. 24A.
The spinhead
2917 has a pair of eyelets 2917b, 2917b' for distributing a first continuous
strand W and a
second continuous strand W' respectively. The eyelets 2917b, 2917b; are
separated by a
distance of 90 (followed by a separation of 2700 in the opposite direction).
In providing
eyelets that are not generally diametrically opposed about the spinhead,
design provisions are
preferably made to provide balance to the spinning spinhead. =
[0096] As comparison, FIG. 25 provides a front view of a spinhead 3017 wherein
a
pair of strand dispenser eyelets 3017b, 3017b' are diametrically opposed and
thus, separated
by 180 (spin phase revolution). The eyelets 3017b, 3017b' are therefore
equidistantly
spaced from each other in either direction. Operaticin of this spinhead 3017
generates a web
putput 3060 whereon each successive pair of elastic *elements 3022a, 3022b are
ultimately
separated by a pitch n, as discussed previously.
[0097] FIG. 13A depicts an elastic composite 210' manufactured in accordance
with
the method previously described in respect to the system of FIG. 15.
Specifically, the elastic
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22
composite 210' is manufactured by an MSSP method. The elastic composite 210'
includes
sections .and components that are generally identical to those of the elastic
composite 210 in
FIG. 12A, with the exception of the elasticized region 214'. The elasticized
region 214' is
composed of discrete groups 322' of multiple elastic elements that extend
generally in the
.5 . lateral direction. The center of the groups 322' of elastic elements are
spaced apart from one
another in generally parallel relation by the same fixed distance n (from Fig:
17) (a center-to- =
center distance). In accordance with the method previously described in
respect to the system
of FIG. 15, a group 322' of elastic strands is delivered to the web upon eaah
revolution of the
spin head. In the elastic composite 210' depicted in FIG. 13A, the groups 322'
consist of two
adjacent elastic elements.
[0098] FIG. 13B depicts an exemplary elastic composite 1810 according to a
fUrther
embodiment of the present invention. The elastic composite is manufactured by
an MSDP
method, in accordance with an alternative embodiment of the present invention.
The elastic
composite 1810 includes sections and components that are generally identical
to those of the
three previously described elastic composites 210, 1710 and 210', with the
exception of the
elasticized region 1814. In this exemplary elastic composite 1810, two
different groups of
elastic strands 1822a, 1822b are delivered onto the web upon each revolution
of the spinhead.
The lateral centerlines of the groups 1822a, 1822b are spaced apart by the
smaller pitch n' ¨
as with the elasticized region 1714 in FIG. 12B. Assuming that one type of
elastie element is
20= used for the elastic composites in each of FIGS. 12A, 12B, 13A, 13B,
the resulting elasticized
region 1814 in this embodiment imparts a greater degree of elasticity to the
elastic composite
1810 than any of the other arrangements.. A=higher elastic density is achieved
by both
providing for a smaller fixed distance, n', between the individual elastic
elements or groups
and providing for more elastic elements at application by the spin head.
Furthermore, the
speed of the operation is increased from the operation associated with each of
the elastic
= composites in FIGS. 12A and 13A.
[0099] =It should be noted that the elastic elements within each of the two
groups
1822a, 1822b =marbe varied or may be of one type. Further, the constituents of
the other two
group may be !different or identical. =
[00100] The elastic elements are directed generally perpendicular to the
longitudinal or
'machine direction. Further, the elastic elements are structurally independent
of each other,
although in some.embodiments may be of (i.e., severed sections) one or more
elastic strand.
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In FIG. 12A, for example, all of the elastic elements are elastic elements of
a single,
continuous strand, although, in the Composite, the elastic elements are
structurally
. independent. Furthermore, each elastic element generally does not have a
vertical (or
longitudinal) component. As a result, a certain uniformity in horizontal
elasticity is achieved.
In some embodiments, this characteristic provides an elongated elastic
composite that does
not tend to twist or kink when at rest, and at rest, is more uniform and
aesthetically pleasing.
[00101] Table 2 below summarizes some of the benefits and advantages attained
by the
different manufacturing methods discussed above. To facilitate the
comparisons, the number
of elastic elements per unit of linear length provided by the four methods is
the same. Thus,
the tensile and elastic properties of the output elastic composites are
similar.
TABLE 2
Manufacturing method =SSSP ==MSSP SSDP MSDP
Number of elastic elements 1 2 2 = 4
applied per revolution
Machine output 40 m/min 80 m/min 80 m/min 160
m/min
Spinhead speed = 8000rpm =
Elastic elements per linear meter =
=
=400 =
Pitch (separation of elastic 2.5mm 5mm = 2.5rnm
5rrirti
strands)
Examples of Advantages = *Efficiency: Aesthetic:
Efficiency:
Pitch is 'A of
Output
Output
=that for MS SP
Increased by
Increased by
100% Efficiency:
300% over
=
Output SSSP
= Increased by
100% over
SSSP
= =
*Formula for machine efficiency: Output (m/min) = spinhead speed (rpm) x no.
of elastic
elements applied per revolution x pitch x 2.
= [00102] Table 2 illustrates the design and 'operational flexibility
attainable through
employment of the various methods previously described. As will become
apparent to one
skilled in the art provided with the present disclosure,. certain methods may
prove more useful
= =
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than others depending on the particular design and operational requirements.
In this regard,
attention is now directed to the systems available to implement these
manufacturing methods.
[00103] With reference to Figures 14A and 14B, a method of making an elastic
composite of the invention utilizing a dual path method is now described. The
inventive
method is described in conjunction. with a description of an exemplary system
1901 of
making the elastic composite.
[00104] FIGS. 14A and 14B depict a system 1901 and system components, and
illustrate a method of making an elastic composite (e.g., elastic composite
1710 or 1810)
according ,to the present embodiment. The system and its components are
substantially =
similar to those previously described. The differences between the previously
described
syStems and the system 1901. of FIGS. 14A, 14B represent improvements provided
by the
present invention. These differences will be the focus of the following
description.
[00105] For purposes of the present description, references will be made to
upper and
lower relative positions, as well as right and left directions and positions.
It will be
understood by one skilled in the art that these.positional and directional
references are made
for description only,, and that the invention is not to be limited by their
Use. Further, it will
become apparent that variations of the system and process may be made,
utilizing different
positions and directions for the various system components and feeds.
[00106] For the most part, the system 1909 includes the same components
provided,.
for example, in the system depicted in FIGS. 5-11. The system 1901 includes a
conveyor
= assembly 1909 for receiving, manipulating, and conveying each of the two
nonwoven web
inputs. The conveyor assembly 1909 is positioned next to, and operatively
associated with,
an elastic element applicator in the.form of a spinning head assembly 1907.
The spinning
head assembly 1907 is operable to apply elastic fibers or strands upon, onto,
and/or integrally
with an input web of nonwoven conveyed by the conveyor assembly 1909. The
spinning
head assembly 1907 further includes a spinhead 1917, preferably in the form of
a spinning
bracket or cylinder 1917 (spinhead). The spinhead 1917 is configured to hold
an "end
section" of the continuous strand WW of elastic element and move it about a
generally
vertical plane XX in a reciprocal or repetitive manner (relative to the
conveyor assembly
1909). As described previously, this Plane XX is defined by the area within
the spinning
perimeter of the cylinder 1917 that is traced by the outer-most bracket or eye
1917b securing
the continuous strand WW to the spin cylinder *1917. It is understood that the
vertical plane
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XX need not be at 90 to the web platforms U, L (and thus, to the web plane
moving
direction), but it is generally preferred. The path of the spinning head 1917
and the section of
elastic strand retained thereby are provided on the plane XX. In FIG. 14A, the
section of
strand WW between the eyelet 1917b and the platform U is indicative of a
linear portion of
5 the plane XX. =
[00107] Referring also to FIG. 16A, the conveyor assembly 1909 includes an
upper
conveyor or web moving platform U (web platform U) providedby a movable,
continuous
belt Ul and a series of rollers supporting the belt U1. The conveyor assembly
1909 further
includes a lower conveyor or web moving platform L (web platform L) also
provided by a
10 movable, continuous belt Ll and a series of-rollers supporting the belt
Ll. In the side view of
FIG. 19B, the lower belt Ll is positioned in generally parallel relation with
the upper belt Ul
and vertically spaced therefrom by a distance or gap HH. Although the belts
Ul, Ll are
designed for reciprocal motion during system operation, the belts Ul, Ll may
be described as
having a planar outside deck or surface Sl, S3 and a planar inside deck or
surface S2, S3 at
15 any fixed point in time (for purposes of the present description). The
use of "inside" and
"outside" references are made in view of the relative locations.of the
surfaces (i.e., facing
outside of the assembly 1909 or facing inside the assembly 1909). This use of
such
references is provided to facilitate the description only, and should not be
construed as a
limitation on the inventive system and method.
20 = [00108] As represented in the plan view of FIG. 14B; each of first and
second primary
inputs webs w1, W2 provide a web of nonwoven utlizing a series of rollers and
guides. The =
two webs Wl, W2 are first directed through folding guides or plates, which
serve to
effectively reduce the overall width of the nonwoven web by folding the ends
or, side edges ,
along a predetermined, longitudinally extending side fold line. As previously
described, the
25 input webs Wl, W2 are directed centrally into the gap HH between the
upper and lower web
platforms U, L, along a first web plane moving direction, MM and toward the
spinhead 1917.
This first web plane moving direction MM also corresponds to a direction from
right to left in -
the side view of FIG. 14B. This first web plane moving direction MM also
directs the
nonwoven inputs. 1903a, 1903b toward the center of the spinhead 1907. Once
inside the
spinhead 1917, the conveyor assembly 1909 reverses the direction of travel of
the input webs
Wl, W2 (a turn of 180 degrees), from the first web plane moving direction MM
to the
oppositel); directed second web plane movingdirection NN. The second web plane
moving
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direction NN is identical (orientation) to the first web moving plane.moving
direction MM,
except that the directions are reversed.
[00109] As the input webs Wl, W2 exit the spinhead 1917, a first elastic
strand WW is
wrapped around the entire conveyor assembly 1909 and contacts the outside
surfaces Sl, S3
of the belts Ul, Ll, respectively. The first elastic strand WW also comes into
Contact with =
the moving webs Wl, W2. The elastic strand WW is applied crosswise or
laterally on the
web, and transverse to the second web plane moving direction NN. As explained
previously,
this transverse direction is also the cross-machine direction. Friction
between the elastic
strand WW and the input webs Wl, W2 on the belt surfaces Sl, S3, helps to draw
the =
10. "wrapped" elastic strand WW out of the spinhead 1917.
[00110] As already described, the system 1901 positions a first elastic input
source El
on the left side of the system 1901 (in the views of FIG. 14A, 14B). The input
source may be
in the form of a spool of elastic. The continuous first elastic strand WW is
delivered through
a hollow shaft in a motor that controls the spinhead 1917. The elastic strand
WW then passes
into the spinhead 1917 and is guided by rollers, eyes, or other suitable
means, around the
inside of the cylinder of the spinhead 1917: .
[00111] In this particular embodiment of the present invention, the system
1909 further
employs a second elastic input source E2 that is, in the views of FIGS. 14A,
14B, positioned
= on the right side of the system 1901. A second continuous elastic strand
WW' may be
delivered via any suitable system of rollers and eyes, centrally along the gap
HH and into the
open end of the spinhead 1917. Upon exiting the gap HH, the second continuous
elastic
strand WW' is directed across the center of the spinhead 1917 and to the back
of the spinhead
1917. The second continuous elastic strand WW' is then guided by rollers,
eyes, or other
suitable means, around=the inside face of the cylinder, to an eyelet 1917b'
positioned
diametrically opposite (180') of the eyelet 1917b of the first continuous=
elastic strand WW.
Thus, the first and second elastic strands WW, WW'are separated by 180 ,
within the spin
cylinder. By taking opposite paths around the spinhead, the risk of
entanglement between the
two continuous elastic strands WW, WW' is substantially alleviated. Further,
the elastic
strands WW, WW' are preferably tensioned by passing the continuous strand
through any
suitable tensioning unit prior to being received b the spinhead 1917. =
= [001121 As the spinhead 1917 is spun around the upper andlower platforms
U, L,
sections of the first and second elastic strands WW, WW' are applied
simultaneously about
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the two web moving platforms. U, L. Referring to the exemplary spinhead 1917
of FIGS.
14A and 14B, the eyelet 1917b' for the second elastic strand WW' is shown at a
position
slightly forward of the eyelet 1917b of the first elastic strand WW.
Preferably, the eyelets
1719a, 1719b are not separated as such, but aligned so as to provide a common
vertical plane
XX. The mis-alignment depicted in FIGS. 14A, 14B are provided primarily to
best show the
distribution of elastic strands WW, WW' about the conveyor assembly 1909.
= [00113] It is contemplated, however, that certain other applications may
be best
implemented by positioning one eyelet forward of the other, as shown. In such
an
npplication, the generally vertical plane XX, about which the first elastic
strand WW is spun,
is slightly left of a second generally vertical plane XX' (not shown), about
which the second
elastic strand WW' is spun. The two vertical planes XX, XX" are disposed in
mutual parallel
relation and both intersect the upper and lower platforms U, L. The elastic
elements WW,
WW' are applied onto the moving webs at these linear intersections of the
vertical planes
XX, XX' with the belt surfaces S1, S3 (i.e., along the web path of the
nonwoven webs). The
positions of the eyelets 1917b, 1917b' may be adjusted to achieve the desired
pitch n'
discussed =above.
[00114] In a further embodiment initially described in respect to FIGS. 24A,
24B, the
position of the eyelets 1917b, 197b' are not diametrically disposed but
positioned less than
180 degrees apart. In this way, the pitch between elastic elements may be
adjusted to satisfy
design requirements. The eyelets 2917b, 2917b' in FIG. 24A are positioned
about 90 degrees
apart in one direction and about 270 degrees in the opposite direction.
Operation of the
spinhead 2917 provides for a web substrate 2960 whereon the elastic elements
2922a, 2922b
(from elastic strands W and W', respectively) are separated by alternating
pitch distances of n
(n1) and 3n (n2).
1001151 FIGS. 15A and 15B depict an alternative system 2001 (to the system
1901 of
FIGS. 14A and 14B) for making the elastic composite according to the invention
(wherein
like reference numerals are used to indicate like elements)., .In this
embodiment, a bracket
system 2090 of tensioning rollers is provided proximate the end of the web
platforms U, L
and the end of the gap HH. The bracket system 2090 directs the second
continuous elastic
'strand WW away from the centerline AA of the spinhead momentarily to avoid
front rollers
2084. The bracket system 2090 may be supported or suspended between the upper
and lower
webplatforms U, L, and in between the input webs Wl, W2, by any suitable
means.
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[00116] Returning to FIGS. 14A and 14B, further description of the invention
system
and method will now be= provided, particularly that of the intersection
between the primary
input webs W1, W2, continuous strands WW, WW', and secondary input webs W3,
W4.
FIGS. 16A-16D provide cross-sectional views through the system 1901.depicted
in FIG. 14.
These simplified views are provided to illustrate certain points in .the
process of applying
= elastic elements onto the nonwoven webs. Referring to FIG. 16A, a first
cross-sectional
view also is presented proximate the ends of the two web platforms U, L. The
view reveals =
cross-:sections of the two continuous belts Ul, Ll. This view includes cross
sections showing
outside belt surfaces Sl, S3, and inside belt surfaces S2, S4. As viewed in
FIG. 16A, the two
inside belt surfaces S2, S4 move out from the page along the first web plane
moving= direction
MM and convey the input webs W1, W2 into the spinhead 1917. The two outside
surfaces
Sl, S3 move into the page along the second web plane moving direction NN and
convey the
webs Wl, W2 away from the spinhead 1917. The input webs W1, W2 of nonwoven are
=
shown on the belts U1., Ll with their ends already folded.
[00117] As used herein, the term "web plane path" shall mean the path
(including
direction) taken by the input webs W1,=W2 as conveyed by the conveyor assembly
1909. For
one input web, the "web. plane path" includes the path along the inside
surface S2 of the
continuous belt U1= directed along the first web plane moving direction MM and
the path
along the outside surface S1 of the same belt Ul directed along the second web
plane moving
direction NN. The web plane path of the other input web is different from the
first web plane=
path, although it is also directed, in certain segments of the path, in the
same web plane
moving directions MIVI or NN. As described herein, the vertical plane XX, XX'
intersects the=
web plane path on the outside belt surface S1 and along a transverse line
common with the
web plane path. =
[00118] Referring to FIG. 16B, a cross-sectional view is provided across a
section
.further away from the spinhead. At this point in the process, the spinhead
1917 has applied
several sections of the first and second continuous elastic strands WW, WW'
about the
conveyor assembly 1909, and more specifically, over the input webs Wl, W2. In
doing so,
the spinhead 1917 has applied the continuous elastic strands WW, WW'
transversely in
respect to the second web plane moving direetion NN.
[00119] Referring to FIG. 16C, a cross-sectional view is provided across a
section
downstream of the rollers for the third and fourth input webs W3, W4 of
nonwoven. The
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rollers facilitate the application of a second web layer upon each substrate
that now includes .
the elastic elements and a first nonwoven web. In this manner, a moving web of
elastic
composite is produced consisting of a top layer of nonwoven sheet, a base
layer of nonwoven
sheet, and elastic elements sandwiched therebetween. At this point, the ends
of the input
webs Wl, W2 are still folded around the ends of the belt surfaces Sl, S3. The
view of FIG.
21C also indicates the locations of knife mechanisms KK where the elastic
strands WW,
= WW' are cut immediately downstream of the cross-sectional view.
As.discussed previously,
the cuts may be provided by knife structures located adjacent the web
platforms Ul, Ll.
[00120] Thecross-sectional view of FIG. 16D represents a point further
downstream in
the process. In this view, the continuous elastic strand WW, WW' has been Out
to provide a
distribution of segmented elastic elements 1722 within the web substrate.
Every other
segmented elastic element 1722 in the distribution is characterized as having
originated from
the same first or second continuous elastic strand. Further, each pair of
adjacent or
sequential elastic element 1722 are characterized as having originated from a
different
. continuous elastic strand. This view also reveals that the first and second
input webs 1903
have been unfolded, in a manner described previously. FIG. 16D depicts,
therefore, a cross-
section of web outputs 01, 02 of the system and method of manufacture,
according to the
invention.
= [00121] FIG. 17 provides a simplified flow chart of the basic steps of a
method of
.20 making an elastic composite, in accordance with the present invention.
The flow chart 2210
also provides a summary of the process described in respect to FIGS. 19-21.
The basic steps
of the method are preferably performed through operation of a system such as
the exemplary
systems 1901, 2101 of FIGS. 14 and 15. In an initial step 2210., a first web
of material (e.g.,
= a nonwoven layer) is conveyed along a web plane path. The web plane path
is simply a path
along which a web having an expanse (i.e., width and substantial length) may
be conveyed.
= The web plane path is preferably controlled by a fixed system to provide
a consistent path for
a moving, continuous web, directed along a predetermined web direction (which
is planar).
As illustrated previously, the web plane path is generally predetermined, in
the preferred
embodiment, by the web platforms of a conveyor assembly and the conveying step
2210 is
.30 implemented through operation of the web platforms. A section of a
first continuous elastic
strand is then applied onto the first web and generally transversely to the
web plane path
(Step 2214). Further, a section of a second elastic strand is applied onto the
second web and
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generally transversely to the web plane path (Step 2218). These steps 2214,
2218 are
preferably performed through operation of a single spinhead that spins the two
strands about
the first web being conveyed and about a plane(s) that intersects the moving
web. By
repeating the applying steps while performing the conveying step, a plurality
of sections of
5 the first and second elastic elements is arranged on the first web in
generally parallel relation
(Step 2222). As previously explained, this plurality of elastic elements
distributed
longitudinally along the web and in mutual parallel relation provides an
elasticized region in
the web output and in each individual, finished elastic composite product,
according .to the
. present invention.
10 [00122] FIGS. 13-17 depict a system and system components, and
illustrate a method
. of making an elastic composite according to another einbodiment of the
invention. Again,
= the depicted system and its components are substantially similar in
structure and operation to
those previously described. Applicable detail descriptions of the system
components and
operation may be borrowed from earlier portions of this disclosure.
Differences between the
15 previously described systems and the systems to be described represent
or arise from
improvements provided by the presentembodiment. Such differences are discussed
herein in
more detail.
[00123] FIG. 18 provides a plan view of the inventive system 2301. FIG. 19
provides
. a perspective, isometric view that reveals several of the components of the
inventive system.
20 Directional arrows are provided throughout FIG: 19 to indicate the
movement of conveyors,
web of materials or elastic composites, the spinhead assembly, and the like.
[00124] In this particular set of embodiments, a system provides and a method
is
implemented for making an elastic composite, whereby a continuous strand of
elastic is -
applied onto a first and a second web along a direction generally transverse
to a web plane
25 moving direction. In these embodiments, the first and second input webs
are conveyed along
the web plane moving direction. This means that a plane may be extended from
(and
including) one web into (and including) the other web, and the two webs move
along that
plane in the. same direction (L e., parallel directional vectors, such as 90
degrees horizontally
and vertically of the vertical plane XX). The two moving webs are, therefore,
generally
30 coplanar about the locations or sections Whereupon a section of the
elastic strand is applied to
both webs. Moreover, the section of elastic strands is applied generally
"linearly" onto both
the first and second webs. As used heretofore, this reference to the section
of krand being
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applied "generally linearly" means that the applied section generally
=provides a linear
segment that extends across the planes of both the first and second webs and
includes a
shorter linear segment on each of the first and second webs.
[00125] Referring to FIGS. 18 and 19, as well as the cross-sectional view of
FIG. 25A,
a system 2301 is provided to implement the inventive method and produce a web
output 01
of inventive elastic composite and preferably a second web output 02. A
conveyor assembly
. .2309 is provided having a web platform U and preferably a second web
platform L (for
outputting second web output 02). In this embodiment, an upper web platform U
is
positioned above, and generally aligned with, a lower web platform L. Each web
platform U,
L is referred to as having a pair of conveyors in the form of movable
continuous belts.
Referring specifically to the cross-sectional view of FIG. 20A, a left
continuous belt Ul of
the upper platform U is spaced laterally from a second continuous belt U2.
Lower web
platform L also has similarly positioned left continuous belt Ll and right
continuous belt L2.
[00126] The continuous belts Ul and U2 are referred to as having, at any given
point
in time, an inside deck or surface S3, S4 that is moving toward the spinhead
2317 (in the web"
plane moving direction MM) and an outside deck or surface Sl, S2 that is
moving away from
the spinhead 2317 (in the web plane moving direction NN). As will be further
described
below, the outside surfaces S3, S4 are generally co-planar or at least
corresponding sections
of the surfaces S3, S4 are, such that sections of input webs supported: on the
corresponding
sections are co-planar and positioned to receive a section of elastic strand
that extends
lineealry across the two webs. Similarly, continuous belts Ll, L2 have inside
suifaces S7,
S8, which are moving toward the spinhead 2317, and outside surfaces S5, S6,
which are
moving away from the spinhead. Accordingly, the pair of inside surfaces for
each web
platform may be referred to as being generally disposed on the same imaginary,
extended
plane and the pair of outside surfaces may be referred to as being generally
disposed on
another imaginary, extended plane. In these preferred embodiments, the two
imaginary,
extended planes are spaced vertically apart and generally disposed in parallel
relation. Thus,
S1 and S2 are generally on the plane, as are S3 and S4, S7, and S8, and S5 and
S6. The pairs
of continuous belts are, therefore, operable to convey a pair of input webs
along a
predetermined web plane path, first along a first web plane moving direction
toward the
= spinhead and a second, reversed, web plane moving direction away from the
spinhead. It is
. preferred, of course, to convey the pair of input webs at the same time.
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[001271 An elastic applicator assembly 2307, including a spinhead 2317, in
this
embodiment, has a construction that is consistent with that previously
described in respect to
FIGS. 5-8. It will be apparent, however, that sizes and dimensions may be
different to
accommodate the dual web platform assembly. In any event, a single input
source El of a
continuous elastic strand WW is provided and received.by a motor operatively
associated
with the spinhead described before. The spinhead 2317 includes arms as
described
previously, and a series of rollers and eyelets for routing and applying the
continuous elastic.
strand WW about the conveyor assembly 2309 and about the generally vertical
plane XX.
[00128] Referring now to FIG. 19, this exemplary system is provided with four
=
independent sources of a primary input web of nonwoven: a first input web W1
*arriving from
an upper part of the system; a second input weby2 lower web arriving also from
an upper
part of the system; a third input web W3 generally below the first input web
Wl; and a fourth
input web W4 generally below the second input web W2. Each of the four primary
input
webs W1-W4 is preferably processed through a folding mechanism, as described
previously.
. 15 The four input webs are then moved along a first web plane moving
direction MM and in
between the upper and lower web platforms Ul, Ll. Movement of the input webs
is, of =
course, driven by the four continuous belts Ul, U2, Ll, L2.
1001291 The exemplary system is further provided with an upper secondary input
web
W5 of nonwoven positioned above the conveyor assembly 2309 for applying a base
layer
simultaneously to a pair of elasticated substrates as will be described below.
Similarly, a.*
lower secondary input web W6 is provided for applying a base layer, as will
also be
= discussed below. Finally, a pair of large rollers 2342, 2344 is
positioned downstream of the
conveyor assembly 2309. Each roller serves to output a web 01 or 02 of elastic
composite
from the system. For this exemplary system and process, that web output 0.1,
02 will
provide a dual-elasticized elastic composite 2322 according to the invention.
=
[00130] Each of FIGS. 20A-20C provides a cross-sectional view through various
points in the process and through sections of the system depicted in FIG.= 23.
The cross-
sectional view of FIG. 25A is placed to highlight the two web platforms U, L,
the four
= continuous belts Ul, U2, Ll, L2, and the four input webs W1-W4 conveyed
thereon. The
30*
four webs W1-W4 are conveyed in a direction coming out of the page and toward
the
spinhead (i.e., first web plane moving direction MM). As also shown in FIG.
20A, the ends
of the input webs WI-W4 enter the spinhead 2317 in a folded configuration.
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[00131] The cross-sectional view of FIG, 20B is provided downstream of the
spinhead
2317 and of the vertical plane XX. Thus, an elastic strand WW is applied
continuously about
the conveyor assembly 2309 and upon each of the four primary webs W1-W4 of
nonwoven.
Friction between the input webs W1-W4 and the applied elastic strand WW helps
draw the
continuous strand WW from the spinhead 2317.
[00132] Turning to FIG. 20C, the cross-sectional view is moved further
downstream in .
the process. Specifically, the cross-section is provided at a point in the
process after
application of the secondary web inpins W5, W6. In one aspect of the present
invention, one
secondary input web is used in conjunction with the two primary input webs to
creat the
elastic composite. A secondary nonwoven is shown applied upon the substrate
combination
of elastic elements and adjacent pair. of input webs (W1 and W2; W3 and W4).
The
application of the secondary input web W5, W6 of nonwoven provides, therefore,
an elastic
composite: FIG. 20C also illustrates the use of central folded section F.1, F2
in each .
secondary input webs W5, W6. The secondary input web W5, W6 is folded so as to
later
reveal a central dead zone between two elasticized regions of the elastic
composite. This
feature of the.inventive elastic composite is discussed in further detail
below.
[00133] FIG. 20C also indicates the location of a knife mechanism KK.
downstream of
the cross-section as discussed previously. At these horizontal locations, the
knife
mechanisms cut elastic strand WW, thereby severing elastic elements from the
continuous
strands. The cuts also separates the process into an upper process and a lower
process. More
specifically, the cuts separates the upper, moving substrate consisting of
input webs Wl, W2, .
secondary input web W5 and elastic elements therebetween, from a similarly
constituted
lower, moving substrate. Additionally, another pair of knife mechanisms KK' is
positioned
at locations downstream of the cross-sectional view and, above, and below, the
centers of the
= web platforms U, L. The knife mechanisms KK' are located. to purposefully
coincide with
the middle of the central folded sections Fl, F2. At these locations, the
continuous elastic
strand WW (or elastic element, if knife Mechanisms KK.' are downstream of
knife
mechanisms KK) is severed to provide a left and right elastic segment or
element in the
finished elastic composite. As already discussed, this also provides right and
left elasticized
regions and leaves the central part of the web absent of. elastic elements.
Thus, when the
folded sections F1, F2 is unfolded, the central dead zone is needed.
=
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[00134] FIG. 21 provides a cross-sectional view of a finished web output of
the system
and process. Two identical web outputs 01, 02 of elastic composites are
provided.
= Referring to the web 01, a first nonwoven layer is provided by the pair
of primary input webs
= Wl, W2, a second nonwoven layer is provided by the single secondary input
web W5, and a
pair of elasticized regions 2614 therebetween make up the finished elastic
composite web.
The elasticized regions 2614 are provided by a distribution of elastic
elements 2622 that are
=in generally parallel relation and extend laterally. The elastic elements
also provide, as a
result, elasticity in the lateral direction and without a vertical component.
The two elasticized
regions 2614 are laterally spaced from one another to provide a dead zone 2650
therebetween. As discussed above, the dead zone results from cutting the
elastic strand WW
or elastic element using the knife mechanisms KK' and the unfolding of the
folded sections =
Fl, F2. Dead zones are also provided between the side edges of the nonwovens.
and each of
the elasticized regions: The side dead zones result partly from the unfolding
of the= folded
ends of the primary input webs W1 -W4. These unfolding steps may be performed
immediately downstream of the .two knife mechanisms in a manner previously
described in
this disclosure.
[00135] The width of the central non-elasticized region or dead zone 2650 may
be
= controlled by controlling the lateral separation between the pairs of
belts in each web
platform (e.g., the space between Ul and U2 and the space between Ll and L2).
It may also =
be contrglled by specifying the width of the excess fold in the center of the
secondary web.
This fold is configured to retain some of the material away from the composite
during the
process and is typically opened up downstream to reveal=the central non-
elasticized region or
dead zone.
[00136] In an alternative embodiment, the system 2301 and method are modified
to
produce four web outputs and four separate elastic composites, according to
the present
invention. In one variation, the knife mechanisms KK' may be modified to also
sever the
secondary input webs W5,W6 (in addition to the elastic strand WW): =In this
way, each of the
two web substrates is divided to produce an independent elastic composite to
the left and also
to the right of the knife mechanisms KK'. Each elastic composite has a single
central
- 30 elasticized region and two side dead zones: In the method to create
the pairs of elastic
composites, the width of the folded sections FL F2, may be provided to
correspond with the
= folded ends of the primary input webs.
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[00137] In yet another alternative embodiment, four independent secondary
input webs
are used instead of two. Each secondary input web joins with a primary input
web, with
elastic elements, thereon, to produce an elastic composite having a
centralized region. The
elastie composite also has a pair of dead zones on either side of the central
elasticized region.
5 [00138] FIG. 22 provides a simplified flow chart of the basic steps of a
method of.
= making an elastic composite, in accordance with this embodiment of the
present invention.
The flow chart 2700 also summarizes the process described above in respect to
FIGS. 23-25.
The basic steps of the method.are preferably performed through operation of a
system such as
the exemplary system 2301 in FIGS. 18 and 19.
10 [00139] In initial steps 2710, 2714, a first web= of material is
conveyed along a web
plane moving direction and a second web of material is conveyed along the web
plane
moving direction. Preferably, the web plane moving direction is predetermined
by the web
platforms of a conveyor assembly and the conveying steps 2710, 2714 are
implemented
through operation *of the web platforms. A section of a first continuous
elastic strand is then
15 applied generally linearly onto both the first and second webs along a
direction generally
transverse to the web plane moving direction (Step 2718). The applying step
2718 is
preferably performed through operation of a spinhead that spins the elastic
strand about the
first and second webs as these webs are conveyed along the web plane moving
direction. =
Preferably; the applying step 2718 is performed while performing the conveying
steps 2710,
20 2714 such that a plurality of sections of the first and second elastic
elements are arranged on
each of the first web and the second web in generally parallel relation. The
elastic elements
are distributed longitudinally along the web and in mutual parallel relation,
so as to provide,
in the finished elastic composite, an elasticized region. In one embodiment,
the first and
= second webs Provide a top or base layer and the first and second
arrangements of elastic
25 = elements provide the pair of elasticized regions.
[001401 Each of FIGS. 23A-23C illustrates an elastic composite 2810, 2810',
281Creontaining a pair
of elasticized regions 2814, 2814', 2814" and three non-elasticized zones or
dead zones, including a central
dead zone 2850, 2850', 2850" extending longitudinally between the two
elasticized regions 2814, 2814',
2814" and side dead zones (2816, 2816', 2818"), (2816, 2816", 2818") on the
other side of each elasticized
30 region 2850, 2850', 2850". The elastic composite 2810, 2810', 2810" may
be referred to herein as a dual-
elasticized elastic composite. In FIG. 23A, the elastic composite 2810 shown
is formed from two discrete
composite sections Cl, C2. Each composite section CI, C2 is manufactured
independently as a discrete elastic
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composite having a single elasticized region. Any one of the three methods
described herein
may be employed to make the singly elasticized composite section. To form the
dual-
elasticized elastic composite, two of the singly elasticized composite
sections are joined
=
together by overlapping one side edge of one composite section over a side
edge of the other
composite section. A suitable adhesive or adhesive=means may be used to
maintain bonding
at the overlap. The overlap creates a multi-layer bonding portion B as shown
in FIG. 28A,
which also serves as a *portion of the central dead zone.
[00141] The bonding portion B consists of a top nonwoven layer 2818 and a base
layer
2820 of each composite section. Accordingly, the thickness of the bonding
portion B and the
central dead zone 2850 may be significantly, or at least observably, greater
than the thickness
of the rest of dual-elasticized elastic. composite. For each composite section
C1, C2, the top
nonwoven layer 2818 and the base nonwoven layer 2820 have the same width and
the side
=
edges are aligned.
[00142] Turning to FIG. 23B, a second dual-elasticized elastic composite 2810'
is
shown again consisting of two adjoined singly elasticized, composite sections
C1', C2'. For -
each composite section C1', C2', one of a top layer 2818' and a bottom layer
2820' is wider
than the other. Referring to the view of FIG. 283B, the right composite
section C2 has a
= bottom layer 2820' that extends laterally farther than the top layer
2818', thereby forming a =
step. For the left composite section, the top layer 2818' extends laterally
farther than the
bottom layer 2820', thereby forming a ledge. By abutting the !edged side=edge
to the stepped
side edge, a suitable construction joint is provided between the two composite
sections C 1',
C2'. An overlapping bonding portion B' (and central dead zone 2850') is also
provided that
consists of a single top layer 2818' and a single base layer 2820' and is
characterized by a
thickness generally consistent with the other portions of the dual elasticized
elastic composite
2810'. A suitable adhesive or adhesive means may be employed to facilitate and
maintain
= .bonding between the layers of the bonding portion.
[00143] FIG. 23C illustrates an improved dual elasticized elastic composite
2810" that
may be manufactured in accordance with the method described in respect to
FIGS. 18-21, in
accordance with the present invention.= In addition to a pair of elasticized
regions 2814", the
elastic composite also has two side dead zones 2816" and a central dead zone
2850" situated
between the elasticized regions 2814"; The thickness of the dead zone 2850" is
provided by
a single top layer 2818" and a single base layer 2820" and is, therefore,
consistent with the
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thickness of other portions of the dual elasticized elastic composite 2810".
In one aspect of
the present invention, the dual elasticized elastic composite 2810" provides a
single
composite-structure. The base layer 2820" of the elastic composite 2810" is
provided by a
seamless sheet of nonwoven (or other material). The elastic composite 2810"
does not
require joining of two discrete elastic composite sections. Rather, a web of
the dual
elasticized elastic composite 2810" is generated linearly as output of the
method described in
respect to FIGS. 18-22. A seamless composite structure, the dual elasticized
composite 2810
eliminates the bonding region required of the elastic composites in FIGS. 23A
and 23B and
thus, avoids the potential for leakage generally associated with these bonding
regions B, B'.
The seamless composite structure is also more structurally sound than the
other composites .
and has a higher tensile strength (laterally and longitudinally).
[00144] As used herein, the term "seamless composite structure" shall refer to
a
structure that does not have a seam at which two or more originally
independent sections are
joined as one to form the present structure. It should be noted that the top
layer 2818" of the
elastic composite 2810 in FIG. 23C may provide a single seam S" along the
central dead
zone 2850" and thus, may not be referred to as "seamless." This seam S" of the
tap layers
2818" is not, however, a seam of the elastic composite 2810" as that seam S"
does not
extend through the -thickness of the dead zone 2850" and the multi-layer
composite 2810",
and is not required to join two independent sections of the elastic composite
2810".
[00145] As expected, the dual elasticized elastic composite 2810" is generally
easier
to manufacture than the other composites in that it does not require the
joining and bonding
= steps required described previously. It also does not require the
machines or manpower to
implement these steps. Furthermore, the seamlessness of the elastic cOmposite
2810" is
generally more aesthetiCally pleasing than the bonding regions B, B'. By
eliminating or
reducing the use of adhesives, the central dead zone of the present elastic
composite is also
generally cleaner. Further advantages and benefits of the dnal elasticized
composite
according to the invention, or of the method of making same, will be apparent
to one
generally skilled in the art.
[00146] The foregoing description of the present invention has been presented
for
purposes of illustration and description. 'It is tO be noted that the
description is not intended
to limit the invention to the various systems, apparatus, and processes
disclosed herein.
=
Various aspects of the invention, as described above, may be applicable to
other types of
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38
disposable absorbent articles, garments, and the like, and processes for
making the same. For
example, the elastic composite described above, may be incorporated in other
disposable
absorbent garments such as training pants, etc. or in other areas or as other
components of the
garment. The elastic composite may also be incorporated into or with other
garments,
= textiles, fabrics, and the like, or combinations thereof. Moreover, the
various aspects of the
process described in respect to FIGS. 12-23 may be utilized to produce
compositions,
garments and articles other than those described herein. Such variations of
the invention will
become apparent to one skilled in the relevant consumer products art provided
with the
present disclosure. Consequently, variations and modifications commensurate
with the above
teachings, and the skill and knowledge of the relevant art, are within the
scope. of the present
invention. The embodiments described and illustrated herein are further
intended to explain
the best modes for practicing the invention, and to enable others skilled in
the art to utilize the
= invention and other embodiments and with various modifications required
by the particular =
applications or uses of the present invention.
=
=
