Note: Descriptions are shown in the official language in which they were submitted.
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PO A E RA ING PA T ~~TIC~~ZED SIDE PANELS_
Technical Field
The present invention relates ,generally tc;~ a disposable; absorbent
article which is configured as a training pant, and more particularly to a
disposable
absorbent article having elasticized side regions formed with a plurality of
generally
parallel, laterally extending elastic elements for enhanced fit and economical
manufacture.
Background Of The Invention
Disposable absorbent articles, such as disposable diapers and
disposable pant-type garments (sometimes referred to as training pants), have
found
widespread acceptance. Garments of this nature are typically configured for a
single
use, with an absorbent panel or core construction ordinarily provided in an
integrated
structure including a liquid-pervious topsheet or f°acing layer, and a
backsheet or
backing layer having at least a portion which is liquid impervious. Pant-
typr;~ garments
include side seams which can be readily tc7na fear r°e:rznc~val caf the
garment if soiled,
while adhesive-coated fastening tabs, or hook-and-loop fasteners are typically
provided on disposable diapers. Abscarberrt articles of' tfre above nature are
not only
suitable for infants, but can be appropriately sized and ~:orlfigured for
incontinence
use by adults.
Commonly assigned U.S. Patent No. ~i,~03,301 discloses a disposable
absorbent garment of the type suitable for .infant care and fcrr use by
incontinent
adults. In order to enhance the containment characteristics, the construction
inc;Iudes
elastication at laterally opposite side margins of the. construction, thereby
forming leg-
encircling elasticized regions.
The absorbent article disclosed in the above-~ref~renced patent is
configured for enhanced fit by the provision of elastic c~~lerr~ents at the
front and rear
waist regions of the article. Experience has shown that elastication desirably
acts to
conform the article to the wearer, enhancing fit, corrrf'cwrt and containment.
'fhe present
invention is particularly directed to an ahsc>r~b~;rat
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article, preferably configured as training pants, having side panel regions
which are economically elasticized by the provision of a plurality of
generally
parallel, laterally extending elastic strand-like elements.
Summary Of The Invention
A disposable absorbent article embodying the principles of the
present invention can be configured as a pant-type garment or a disposable
diaper for infants or small children, or can be appropriately sized and
configured for use by incontinent adults. 'The article includes an elasticated
waist band, elasticated side regions, and elasticated leg gathers extending
around leg openings and extending upwardly; overlapping the side regions.
The leg openings are thereby substantially completely surrounded by
elastication for better fit and liquid retention. The elasticated side regions
are
economically formed with a plurality of strand-like elastic elements
predominantly positioned laterally outwardly of the absorbent panel of the
article.
The construction of the absorbent article includes an absorbent
panel and a liquid permeable topsheet positioned on top of the absorbent
panel. A backsheet positioned beneath the absorbent panel and extending
laterally outwardly from opposite sides of the absorbent panel at longitudinal
end portions thereof defines a pair of front ear portions, and a pair of rear
ear
pbr~ians. The front and rear ear portions define leg-encircling openings of
the
garment. A central region extends laterally between the front ear portions and
between the rear ear portions, and longitudinally connects the front and rear
ear portions between the legs of the wearer. The central region includes a
crotch portion extending longitudinally between the front and rear ear
portions
of the garment. A pair of side seams respectively joins the front ear portions
to the rear ear portions forming opposite side regions to provide the garment
with a pant like configuration, and also thereby defines a waist opening.
A plurality of generally parallel, laterally extending, elastic
elements joined to each of the front and rear ear portions provides
elastication
thereof, with each of the ear portions being elasticized by the elastic
elements
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substantially throughout its longitudinal extent from the respective one of
the
leg-encircling openings to the waist opening. A pair of elasticized gathers
extends generally longitudinally of the garment at respective opposite sides
of
the absorbent panel, each of the gathers including an outer sleeve having a
base edge fixed to one of the backsheet and the topsheet, and at least one
gather elastic element positioned within a folded portion of the outer sleeve.
The gather elastic element of each gather can be positioned in spaced apart
relationship to the base edge of each respective gather. Each of the gather
elastic elements extends longitudinally along and beyond the crotch portion so
that the elasticized gathers and the elasticized ear portions together provide
elastication substantially completely around each of the leg-encircling
openings of the garment. The outer sleeves of the elasticized gathers can be
formed separately from the topsheet and joined to the topsheet, or can be
integrated with the topsheet such as by formation from the same piece of
material.
A pair of waist elastic regions or bands respectively extend
transversely of the garment beyond each end of the absorbent panel. Each of
the waist elastic regions extends transversely across the central region and
the
respective ear portions to the side seams. The bands can alternately be
localized in transverse extent, not extending across the ear portions. The
waist elastic regions are each preferably formed by a g~urality of elastic
members or elastic strands extending along a length of the regions.
Alternately, one strand may be used at each of front and rear waist regions to
elasticate the waist of the article.
Preferably, at least one of the elastic elements of each leg gather
assembly is positioned in sufficiently closely spaced relationship to
associated
components of the absorbent article for gathering the absorbent article for
enhanced fit and aesthetic appeal. To such end, a base elastic element can be
positioned respectively adjacent to each of the base edges of the elasticized
gathers. Each of the base elastic elements is positioned within respective
folded portions of the outer sleeves.
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In accordance with the illustrated embodiment, the absorbent
panel preferably comprises absorbent material such as comminuted wood pulp
(wood flub with superabsorbent polymer distributed therein. The liquid
pervious topsheet is positioned on top of the absorbent panel, with the
topsheet being positionable generally adjacent to a wearer during use of the
article.
In accordance with the present invention, the pair of
longitudinally extending elasticized leg gather assemblies are positioned on
respective opposite sides of a longitudinal centerline of the article. The
outer
sleeves of the leg gather assemblies are joined to the topsheet of the
article,
and contain at least two, and preferably three or more, elastically
contractible
elastic elements. The elastic elements are positioned in spaced apart
relationship within an upstanding portion of the outer sleeve of each leg
gather assembly, in a manner which desirably acts to distribute the elastic
contraction forces generated by the elements along a substantial portion of
the
vertical extent of each leg gather assembly: To this end, it is preferred that
at
least one elastic element be positioned within an upper half of the upstanding
portion of each outer sleeve. While elastication of the article is effected by
the provision of the elastic elements of the leg gather assemblies, it is
presently preferred that the side marginal portions of the article are not
btlierwise elasticized. The resultant construction not only provides the
desired
containment and fit characteristics, with enhanced aesthetic appeal, but also
facilitates high-speed manufacture for economical use.
In the preferred form, the outer sleeve of each leg gather
assembly comprises hydrophobic nonwoven fabric, and may be configured as
a composite including nonwoven fabric and an associated plastic film layer.
In the illustrated form, the upper sleeve of each leg gather assembly includes
a base portion, which base portion may be joined to a respective lateral edge
of the topsheet and extends laterally outwardly therefrom to a respective side
edge of the article. Alternatively, the topsheet can be configured to extend
laterally outwardly beneath the leg gather assemblies to the side edges of the
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absorbent article, with each leg gather assembly having a ribbon-like
configuration, respectively positioned on top of the topsheet of the article.
The invention provides stretch sides for a pant like absorbent
article without having separate stretch elements bonded to a central region of
the article. 'This configuration of elastic allows the achievement of a better
fit
without laterally gathering or corrugating the central region, particularly
the
tummy area and the crotch portion. The configuration also allows for a
complete elastic encircling of the leg openings leading to better containment
performance.
Other features and advantages of the present invention will
become readily apparent from the following detailed description, the
accompanying drawings, and the appended claims.
Brief Description Of The Drawings
FIGURE 1 is a perspective view of a disposable absorbent
I S article, configured as disposable training pants, embodying the principles
of
the present invention generally as it appears when being worn;
FIGURE 2 is a top perspective view of the present absorbent
article generally in a form prior to final assembly;
FIGURE 3 is an exploded perspective view of the training pants
of FIGURE 2;
FIGURE 4 is a top plan view of the training pants of FIGURE
2;
FIGURE 5 is a fragmentary cross-sectional view taken generally
along lines 5-5 of FIGURE 4;
FIGURE 6 is a fragmentary cross-sectional view taken generally
along lines 6-6 of FIGURE 4;
FIGURE 7 is a fragmentary cross-sectional view taken generally
along lines 7-7 of FIGURE 4;
FIGURE 8 is a fragmentary cross-sectional view similar to
FIGURE 7 showing an alternate construction of the present invention.
detailed Descrlution
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While the present invention is susceptible of embodiment in
various forms, there is shown in the drawings and will hereinafter be
described presently preferred embodiments, with the understanding that the
present disclosure is to be considered as an exemplification of the invention,
and is not intended to limit the invention to the specific embodiment
illustrated.
With reference now to the drawings, therein is illustrated a
disposable absorbent article 10, illustrated as disposable training pants or a
"pull-up" diaper, embodying the principles of the present invention. As used
in the present disclosure, the training pants are intended to refer to an
absorbent article or garment which is worn by an individual for absorbing
urine and/or fecal matter. It is understood that garments embodying the
principles of the present invention are ordinarily sized for use by infants
and
children, but can also be appropriately sized for use by incontinent adults.
While absorbent article 10 has been illustrated as disposable training pants,
it
will be understood that an article embodying the principles of the present
invention can be configured as a diaper, including a fastening arrangement for
fitting the article about a wearer so as to define a waist opening and a pair
of
leg openings.
With particular reference to FIGURE 2, the article is shown
Before final assembly into the configuration of FIGURE 1. The absorbent
article 10 includes a narrow, rectangular rear waist portion I2, a narrow,
rectangular front waist portion 14, and a substantially rectangular central
region 16 longitudinally extending between the front and rear waist portions
12, 14 and including a crotch portion 17. The crotch portion of the garment
generally corresponds to that portion which is positioned between the legs of
a
wearer during use, and as used therein, comprises between about ~/~ and '/. of
the longitudinal extent of the gazment.
The central region 16 also includes a tummy area 17a which is
above the crotch portion 17 and below the front waist portion 14; and a lower
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back area 17b which is above the crotch portion 17 and below the rear waist
portion 12.
Ear portions 19a, 19b, 19c, 19d extend laterally outwardly from
the central region 16, one at each of four corners of the central region. 'The
ear portions 19a, 19b, 19c, and 19d are each bounded by the central region
16, a respective leg cut-out 18 and a respective waist portion 12, 14.
The absorbent article 10 is assembled by side connections such
as a pair of adhesively secured or sonically welded side seams 20, 21 (shown
in FIGURE 1) between edges 20a, 20b and 21a, 21b, respectively, forming a
pant-shaped garment when assembled. When the embodiment of the
invention is configured as a diaper, side seams connections are made by tape
tabs (not shown) which are positioned for securement to the outside surface of
the front waist portion 14, and to this end, a tape landing zone is preferably
provided. The tape landing zone typically comprises a strip of polymeric
sheet material which the tape tabs can be securely, yet movably applied, with
the landing zone desirably acting to reinforce the front outside surface of
the
garment so that removal and re-application of the tape tabs does not damage
the article. A suitable fastening arrangement can alternatively be provided by
the provision of hook-and-loop-type fasteners (not shown), with tape tabs
provided with suitable hook material, and with the region generally
corresponding to tape landing zone provided with suit~l~le loop material.
In accordance with the illustrated embodiment, front and rear
waist elastic regions 42, 44, such as comprising elastic elements or strands,
are preferably provided within the front and rear waist portions 14, 12, along
laterally extending edges of the backsheet 26 for enhanced fit, containment,
and comfort. In the preferred embodiment, a plurality of elastic elements or
strands 104, 105 (shown in FIGURES 3 and 4) span entirely across the front
and rear waist portions 14, 12.
The ear portions 19a, 19b, 19c, and 19d are elasticized by a
plurality of laterally extending, and longitudinally spaced side elastic
strands
106 (shown in FIGURES 3 and 4) which each extend between a respective
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edge 20a, 20b, 21a, 21b of the ear portions and the central region 16. When
the ear portions 19a, 19b, 19c, and 19d are respectively connected along the
edges 20a, 20b, 21a, 21b to form the structure of FIGURE 1, the ear portions
19a, 19b, 19c, and 19d together form elasticated, opposite side regions of the
article 10.
It is presently preferred that both pair of front ear portions 19a,
19b, as well as the pair of rear ear portions 19c, 19d, be elasticized by
strands
106. However, it is within the purview of the present invention that only the
pair of front ear portions be so-elasticized, or only the pair of rear ear
portions. Additional elastic elements can be provided in the ear portions, in
addition to parallel laterally extending elastic elements 106, such elastic
elements extending perpendicularly or diagonally with respect to elements
106, or otherwise, including randomized placement of additional elastic
elements.
With reference to FIGURE 3 through 6, the absorbent article 10
includes a backsheet 26 which generally defines the outer surface of the
garment. The backsheet 26 can be configured as a composite or laminate of
an outer nonwoven fabric layer 102 (such as a carded fabric), and an inner
nonwoven layer 110 (shown partially in FIGURE 3). Alternatively, the entire
backsheet 26 can be formed from suitable polymeric film material (such as a
polyethylene sheet having a thickness on the order of 0.0005 to 0.001 inches).
However, it is presently preferred that plastic film material only be
positioned
beneath the absorbent panel of the article. Polyethylene terephthalate sheet
material having a thickness of approximately 0.0005 to 0.001 inches may
alternately be employed.
The inner nonwoven layer 110 can be substantially coextensive
with the outer nonwoven fabric layer 102, or can comprise a pair of
nonwoven fabric components which respectively extend laterally across and
between the front ear portion and the rear ear portions. 'The laterally
extending ear portions 19a, 19b, 19c, 19d can be extended portions of the
backsheet 26, i.e., composed of the nonwoven layer 102, 110. The ear
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portions (the side regions of the finished article) can thus exhibit desired
breathability (by virtue of the nonwoven fabric material in these areas) for
enhanced comfort by the wearer. When layer 110 is provided in the form of
a pair of nonwoven fabric components, as described above, elastic element
106 can be secured thereto prior to placement on layer 102. The components
of layer 110 can themselves comprise two or more layers of nonwoven fabric,
with elements 106 positioned therein in a sandwich-like fashion.
The absorbent article 10 includes an absorbent panel 28
positioned on top of a liquid barrier film 112 which is secured to the
backsh~et 26, with the barrier film 112 dimensioned at least as large as the
absorbent panel 28. The absorbent panel preferably comprises an absorbent
matriJC including comminuted wood pulp, sometimes referred to a wood fluff,
and superabsorbent material, which may comprise superabsorbent polymers or
the like. Absorbent matrices comprising blends and/or layers of absorbent
material can be employed. If desired, the superabsorbent material may be
concentrated in specifically selected regions of the absorbent panel.
In the preferred embodiment, a liquid distributing transfer layer
29 is positioned on top of the absorbent panel 28. The transfer layer
preferably comprises a low basis weight nonwoven fabric layer, which in a
presently preferred form, comprises thermally bonded bi-component fibers of
polyester and polypropylene, having a basis weight of.40 grams per square
meter. Suitable material can be obtained from Fiberweb North America, Inc.,
under the product designation DFPN156.
Absorbent article 10 includes a topsheet 30 positioned on top of
the absorbent panel 28. The topsheet 30 can be configured in accordance
with the illustrated embodiment, to have a longitudinal extent substantially
extending the length of the crotch portion 17 of the article 10, and a
transverse dimension such that the topsheet 30 has side edges spaced inwardly
of respective side edges of the article 10. In this construction, each of the
side edges of the topsheet 30 is respectively joined to a unitary leg gather
assembly, designated 32, in accordance with the principles of the present
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invention. The outer sleeves of the elasticized gathers can be formed
separately from the topsheet and joined to the topsheet, or can be integrated
with the topsheet.
The embodiment shown in FIGURES 3 and 4 uses a topsheet
30 which has a lateral extent substantially within the central region 16,
i.e.,
not overlying the ear portions 19a, 19b, 19c, 19d. However, it is also
contemplated by the invention that the ear portions 19a, 19b, 19c, 19d can
also be formed by extending portions of the topsheet 30 rather than the
backsheet 26. The ear portions 19a, 19b, 19c, 19d can also be found by
extensions of both the backsheet 26 and the topsheet 30.
FIGURE 3 demonstrates in detail the assembly of the various
layers which together make up the absorbent article 10. The backsheet 26
includes the nonwoven fabric layer 102 upon which is carried the front waist
elastic strands 104, the rear waist elastic strands 105 and the side elastic
strands 106. The elastic strands 104, 105, and 106 are secured by an
adhesive. The elastic strands 104, 105 are separated longitudinally at about a
.25 inch spacing. The side elastic strands 106 are located longitudinally
between the leg openings 18 and the waist elastics 104 and 105 within the
four areas 19a, 19b, 19c and 19d. The side elastic strands 106 pmvide an
elastication of the article 10 through the tummy area 17a, the lower back area
171i,'and around the leg cut-outs 18.
The side elastic strands 106 are installed onto the nonwoven
fabric layer 102 by stretching double-length strands entirely across the ear
portions 19a, 19b, 19c, and 19d and respective tummy and lower back areas
17a, 17b and cutting along a longitudinal centerline CL. Cut ends of the
strands then separate by elastic force from the centerline CL outwardly by
about 4 inches, indicated as dimension F. Thus, the tummy area 17a and the
crotch portion ~ 17 are left non-elasticated. This is an important advantage
of
the embodiment of the invention which avoids gathering or corrugating the
tummy area 17a and the crotch portion 17, for a more comfortable fit and a
smoother appearance of the article.
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The side elastic strands 106 can advantageously be spaced
longitudinally from between 1/16" to 2", and preferably at .25 inches. The
spacing of the elastic strands 106 can be varied. Advantageously, between
fourteen (14) and twenty {20) side elastic strands can be applied to each ear
portion, although the invention is not limited to this range. Preferably,
seventeen (17) side elastic strands, spaced at .25 inches, are applied to each
ear portion. The ear portion dimension "G" can also be about 4 inches, for
each of the ear portions 19a, 19b, 19c, and 19d extending to a respective edge
of the backsheet 26.
The inner nonwoven.layer 110 is adhesively secured covering
the elastic strands 104, 105, 106 and the outer nonwoven layer 102. The
elastic strands 104, 105, 106 are thus captured between the outer nonwoven
layer 102 and the inner nonwoven layer 110.
The barrier film 112 is applied to the inner nonwoven layer 110
and adhesively secured thereto. The core layer 28 is applied onto the barrier
film 112. The transfer layer 29 is applied onto the core 28. The topsheet 30
is applied over the core and transfer layer and onto the barrier film 112.
Opposing leg gathers 32 are applied partially onto the topsheet 30 and also
onto the barrier film 112. The leg gather assemblies are attached along lines
approximately one half inch inward from the edges of the leg openings 18.
Two nonwoven strips 180, 182 are adhesively secured across
the article, securing longitudinal ends 32a of the gather assemblies 32 to the
top sheet 30 and serving a reinforcing purpose. The strips 180, 182 are also
secured along their length to the inner nonwoven layer 110 as shown in
FIGURES 5 and 6.
All the layers which are stacked to construct the article can be
secured using intervening layers or coatings of construction adhesive (not
shown).
FIGURE 4 demonstrates an important feature of the invention in
that the leg gather elastic strands 38, 38' extend longitudinally to overlap
the
side elastic strands 106 by distances 184, 185. When the article 10 is
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assembled, the overlap ensures a complete elastication around the leg cut-outs
18, to provide enhanced containment and fit characteristics.
As shown in FIGURE 7, the topsheet is joined to each leg
gather assembly 32 by a respective bond 33, which may comprise sonic
S bonding or suitable adhesive. Each of the longitudinally extending leg
gather
assemblies 32 is elasticized in a specifically configured arrangement to
provide the desired containment and fit characteristics for the disposable
absorbent article 10. Specifically, each leg gather assembly 32 includes an
outer sleeve 32' preferably comprising nonwoven fabric having an upstanding
portion 34, and a laterally extending base portion 36. Within the outer sleeve
are arranged a plurality of elastic strands 38 and a lowest-most elastic
strand
38'.
In the illustrated embodiment of FIGURE 7, the base portion 36
of the outer sleeve extends laterally outwardly from the topsheet to the
respective side edge of the absorbent article and is joined to the backsheet
26,
particularly the inner layer 110, with suitable adhesive or by sonic bonding
indicated at 35. However, in a presently preferred embodiment, the outer
sleeve can be configured such that the base portion extends laterally inwardly
only or outwardly only, such as in an L-shaped configuration.
As a further alternate design, as illustrated in FIGURE 8, a
wider topsheet 30' can extend beneath each of the leg gather assemblies 32
laterally outwardly toward the side edges of the article 10, and can be joined
to the backsheet 26 with suitable adhesive or sonic bonding. As shown, the
topsheet 30' is secured by a bond 35' to the inner nonwoven layer 110. The
extending base portion 36 is secured to the topsheet 30' by a bond 33' along
an edge inward of the upstanding portion 34, and by a bond 36' along an
edge outward of the upstanding portion 34. The bonds 33' and 36' can be
suitable adhesive bonds or sonic bonds.
As illustrated in the preferred embodiment of FIGURE 7, each
leg gather assembly 32 is arranged to have a generally inverted T-shaped
configuration, wherein the base portion 36 extends beneath, and inwardly and
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outwardly of, the associated upstanding portion 34. While the free edges of
the material forming the outer sleeve ,are illustrated as being positioned at
the
base portion 36, these free edges can be otherwise positioned, such as at the
uppermost position 39 of the outer sleeve 32'.
The upstanding portion 34 of the outer sleeve 32' of each leg
gather assembly provides the desired sleeve-like configuration for each leg
gather assembly within which the plural elastic elements of each leg gather
assembly are positioned. The outer sleeve of each leg gather assembly can be
secured or fined in this narrow sleeve-like configuration by suitable bonding,
such as by the application of spray adhesive 37, or by the provision of
suitable sonic bonding. The walls of the outer sleeve would thus be squeezed
or collapsed together between elastic elements 38, 38' and adhesively secured
in that configuration.
Elastication of the outer sleeve 32' of each leg gather
assembly causes the upstanding portion 34 thereof to assume a generally
upstanding vertical orientation with respect to the associated topsheet 30. By
this arrailgement, each leg gather assembly tends to extend generally toward
the perineal region of the wearer, generally toward what is sometimes referred
to as the "thigh crease".
One or more of the elastic elements 38, 38' act as a crotch
elastic member by respectively extending along each ,side of the absorbent
panel in the crotch portion 17. Each of the crotch elastic members can extend
beyond the crotch portion adjacent to the elasticized regions of the ear
portions 19a, 19b, 19c, 19d. It is presently preferred that base elastic
element
38' only extend along the length of the crotch portion of the article. 'The
elastic elements 38, along with the side elastic elements 106, thus can serve
the function of elasticizing all around the leg openings defined by the cut
outs
18.
In accordance with the present invention, enhanced containment
and fit are provided by the provision of at least two, and preferably three or
more elastic elements within the outer sleeve of each of the leg gather
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assemblies 32. In a presently preferred embodiment, three, and preferably
four, evenly spaced apart elastic elements 38, 38' are provided within the
upstanding portion 34 of the outer sleeve of each leg gather assembly 32. In
a current embodiment, the elastic elements are evenly spaced apart by about
11 mm, with the lowermost elastic 38' spaced throughout its extent from the
backsheet 26 by about 2 mm
As noted above, the leg gather assemblies 32 of the present
disposable absorbent article have been particularly configured for enhanced
containment and fit, thereby permitting the side marginal portions of the
article to otherwise be non-elasticized. To this end, at least two of the
elastic
elements are provided within the outer sleeve of each leg gather assembly,
with at least one elastic element provided in an upper half of each upstanding
portion 34 of the respective outer sleeve, and at least one elastic element
positioned within the lower half of the upstanding portion of each outer
sleeve. In order to create the desired fit characteristics, one of the elastic
elements positioned within the lower half of the upstanding portion of the
outer sleeve can exert a greater elastic gathering force on the outer sleeve
than
one of the elastic elements in the upper half of the upstanding portion. In
accordance with the illustrated embodiment, one of the elastic elements
exerting the greater gathering force, designated 38', is positioned within the
louver half of the upstanding portion 34 of outer sleeve 32', and can be
positioned in spaced relationship from the backsheet 26 throughout its extent.
The lowest-most elastic element 38' can be located in the outer sleeve 32' or
otherwise closely spaced or adjacent to the backsheet.
Thus, the elastic element 38' in each leg gather assembly 32
spaced fuxthest from the uppermost position 39 of the outer sleeve 32' exerts
a greater elastic gathering force on the respective outer sleeve than the
other
ones of the elastic elements.
By the provision of at least three substantially evenly spaced
apart elastic elements 38, 38' positioned within the respective outer sleeve
32', elastic contraction forces generated by the elastic elements are
distributed
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along a substantial portion of the vertical extent of each leg gather
assembly.
By the preferred provision of a lowermost one of the elastic elements being in
a configuration so as to exert a greater elastic gathering force than the
other
ones of the elements, gathering of the backsheet 26, and the associated
absorbent panel 28, at the leg openings, is effected for enhanced fit of the
article, thus enhancing the aesthetics of the article. Enhanced containment is
also achieved by this enhanced fit, since it permits the elasticized
upstanding
portion 34 of each leg gather assembly 32 to conform to the wearer as
intended.
As noted, the preferred embodiment of the present invention is
configured such that the side marginal portions of the article, i.e., those
portions of the construction disposed generally laterally outwardly of bonds
33
(or 33' in FIGURE 8), are non-elasticized, other than by the elastication
provided by the elastic elements 38, 38' of each leg gather assembly 32. As
such, the base portion 36 of the outer sleeve of each leg gather assembly is
non-elasticized, except by any elastication provided by the spaced apart
elastic
elements 38, 38'. However, additional longitudinally extending elastic
elements can be provided generally beneath or outwardly of each gather
assembly 32.
Configuring elastic element 38' for exerting a greater elastic
gathering force on the outer sleeve of each leg gather assembly 32 can be
effected in any of a variety of ways. If desired, the elastic element 38' can
have an untensioned cross-sectional area greater than the other elastic
elements 38, and thus exhibit a greater modules of elasticity. Elastic element
38' can comprise material which is different than the other elastic elements
38, and thus be configured to exhibit a greater modules of elasticity. If
desired, the elastic element 38' can be subjected to greater elongation than
the
other ones of the elastic elements, and thus be configured to create a greater
elastic gathering force than the other elements, even if exhibiting an
untensioned cross-sectional area which is the same as the other elements.
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In the preferred form, the outer sleeve of each of the leg gather
assemblies 32 preferably comprises hydrophobic nonwoven fabric, thereby
resisting the passage of liquid therethrough. A suitable fabric can comprise
spunbonded polypropylene nonwoven fabric having a basis weight in the
range of about 0.03 to 0.8 ounces per square yard and a bond area in the
range of 7% to 20%, with a basis weight of about 0.5 to 0.6 ounces per
square yard, and an 18% bond area being particularly preferred. When
untreated, this material exhibits the desired degree of hydrophobicity. One
commercially available material of this type is available from Fiberweb of
America, Greenville, South Carolina, under the product designation Unicorn
Celestra.
The topsheet 30 (or 30' in FIGURE 8) may also comprise a
polypropylene nonwoven fabric having a basis weight and bond areas
described above for the outer sleeves of the leg gather assemblies 32. While
the liquid permeability characteristics of the topsheet 30 (or 30') can be
selectively varied while keeping with the principles disclosed herein, it is
presently preferred that the topsheet 30 (or 30') be selected to exhibit
significantly greater hydrophilicity, and thus, greater liquid permeability,
than
the outer sleeves 32' of the leg gather assemblies 32. To this end,
polypropylene nonwoven material such as described above is ordinarily
Heated with a surfactant to achieve the desired hydrophilicity. Alternatively,
a
hydrophobic fabric having apertures to permit liquid passage therethrough
may be employed.
In the preferred form, the upstanding portion 34 of each of the
leg gather assemblies 32 is partially secured to the top surface of the
associated topsheet 30 (or 30'). In particular, at least one longitudinal end
of
the upstanding portion 34 of the outer sleeve, of each leg gather assembly is
secured inwardly to the topsheet, such as by suitable adhesive or sonic
bonding, as indicated at 38a. Most preferably, approximately 10% of the total
length of each leg gather assembly 32 is secured at each end of each leg
gather assembly (i.e., 20% of the entire length is attached to the topsheet).
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CA 02303941 2000-03-14
WO 99/13813 PCT/US98/18975
Additional design features are preferred in configuring the present disposable
absorbent article 10 for the desired containment and fit characteristics. It
is
believed that the elastically contractible gathering force asserted from each
leg
gather assembly on the associated article components, including the backsheet
S 26, should effect contraction from a fully elongated length in the range
from
about 20% to SO%. This is preferably achieved by positioning the lowermost
elastic element 38' no more than about .2S inches from the backsheet 26.
The disposition of each leg gather assembly 32 with respect to the associated
absorbent panel 28 is such that the base portion 36 of each leg gather
assembly is preferably no more than about 1 inch away from the narrowest
portion of the absorbent panel, with this base portion being preferably
positioned no more than about 1 inch inwardly from the respective side edge
of the article.
While leg gather assemblies 32 have been illustrated as being
1 S generally linear and in parallel relationship to each other and to the
centerline
of the disposable article 10, it is within the purview of the present
invention
to position the leg gather assemblies in a curved or otherwise non-parallel
configuration. For example, the ribbon-like leg gather assemblies 32
illustrated in FIGURE 7 can be formed to each have a length preferably at
least 10% greater than that of the absorbent article, and then attached to the
article to each define a curved configuration by viriue._gf the "extra
material"
of each leg gather assembly.
From the foregoing, it will be observed that numerous
modifications and variations can be effected without departing from the true
2S spirit and scope of the novel concept of the present invention. It is to be
understood that no limitation with respect to the specific embodiments
illustrated herein is intended or should be inferred. The disclosure is
intended
to cover, by the appended claims, all such modifications as fall within the
scope of the claims.
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