U.S. patent application number 13/517806 was filed with the patent office on 2012-10-04 for combination of refastenable and releasable bonds.
Invention is credited to Walter A. Mattingly, Robert L. Popp, Thomas E. Williamson.
Application Number | 20120246891 13/517806 |
Document ID | / |
Family ID | 37575223 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120246891 |
Kind Code |
A1 |
Popp; Robert L. ; et
al. |
October 4, 2012 |
Combination Of Refastenable And Releasable Bonds
Abstract
A refastenable, pant-like garment, including a chassis including
a first waist region and a second waist region, together defining a
waist opening and first and second leg openings. The garment also
includes a first refastenable seam joining a first distal portion
of the first waist region to a first distal portion of the second
waist region. The first refastenable seam includes a first
refastenable bond connecting the first distal portion of the first
waist region and the first distal portion of the second waist
region having a first refastenable bond peel strength.
Inventors: |
Popp; Robert L.;
(Hortonville, WI) ; Mattingly; Walter A.;
(Appleton, WI) ; Williamson; Thomas E.; (Appleton,
WI) |
Family ID: |
37575223 |
Appl. No.: |
13/517806 |
Filed: |
June 14, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11215865 |
Aug 30, 2005 |
8221378 |
|
|
13517806 |
|
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Current U.S.
Class: |
24/442 ; 24/265R;
24/304 |
Current CPC
Class: |
A61F 13/49004 20130101;
Y10T 24/47 20150115; A61F 13/565 20130101; Y10T 24/27 20150115;
Y10T 24/33 20150115; A61F 13/55115 20130101; A61F 13/5622
20130101 |
Class at
Publication: |
24/442 ;
24/265.R; 24/304 |
International
Class: |
F16B 47/00 20060101
F16B047/00; A44B 18/00 20060101 A44B018/00; A44B 99/00 20100101
A44B099/00 |
Claims
1. A refastenable joint joining a first material having a first end
and a second end to a second material having a third end and a
fourth end, including a refastenable bond connecting the first end
to the third end, the first material being folded and bonded with a
releasable bond wherein separating the second end from the fourth
end initially stresses the refastenable bond and the releasable
bond predominantly in peel, then ruptures the releasable bond
predominantly in peel, then stresses the refastenable bond
predominantly in shear.
2. The joint of claim 1, wherein the third end is folded and bonded
with a permanent bond, separating the second end from the fourth
end initially stresses the permanent bond, refastenable bond and
the releasable bond in peel, then destroys the releasable bond in
peel, then stresses the refastenable bond and permanent bond in
shear.
3. The joint of claim 2, wherein the permanent bond comprises an
ultrasonic bond.
4. The joint of claim 1, wherein the releasable bond has a
releasable bond peel strength, the permanent bond has a permanent
bond peel strength and the refastenable bond has a refastenable
bond peel strength, the releasable bond peel strength is less than
the refastenable bond peel strength, and the refastenable bond peel
strength is less than the permanent bond peel strength.
5. The joint of claim 4, wherein a ratio of the refastenable bond
peel strength to the releasable bond peel strength is greater than
1.5.
6. The joint of claim 4, wherein the ratio of the refastenable bond
peel strength to the releasable bond peel strength is greater than
50.
7. The joint of claim 1, wherein the refastenable bond comprises
hook and loop, cohesive, adhesive or tape.
8. The joint of claim 1, wherein the releasable bond comprises an
ultrasonic bond.
9. The joint of claim 1, wherein the releasable bond comprises a
pressure bond.
10. The joint of claim 1, wherein the releasable bond comprises an
adhesive bond.
Description
[0001] This application is a divisional of application Ser. No.
11/215,865 entitled Combination of Refastenable and Releasable
Bonds and filed in the U.S. Patent and Trademark Office on Aug. 30,
2005. The entirety of the prior application is hereby incorporated
by reference in this application.
BACKGROUND
[0002] Pant-like absorbent garments, such as adult incontinence
wear, infant and children's diapers, swim wear and training pants,
typically have adhesive or mechanical fasteners on the sides for
donning and removal, or else rely on a stretchable waist opening
and leg openings to slide on and off the wearer. Absorbent garments
that slide on and off a wearer can be messy after use. Furthermore,
in order to remove such absorbent garments, the wearer's clothing
covering the absorbent garments, such as pants, must generally be
completely removed. Checking the status of the wearer's absorbent
garment contents can be just as cumbersome as changing the
absorbent garment.
[0003] Refastenable seams including mechanical fasteners, such as,
for example, hook and loop fasteners, have been found to be
particularly beneficial when used in conjunction with pant-like
absorbent garments. Refastenable seams allow for the garment to be
easily applied and removed, as well as periodically opened to check
for exudates and closed if no exudates are found.
[0004] Refastenable seams generally perform much better in shear
than in peel. However in the manufacturing process butt seam are
generally less complicated to construct than lap seams. Butt seams
are stressed predominantly in peel, while lap seams are stressed
predominantly in shear. As a result, there is a need or desire for
refastenable seam that can be constructed as a butt seam but will
convert to a lap seam.
SUMMARY
[0005] In response to the foregoing need, the present inventor
undertook intensive research and development efforts that resulted
in the discovery of a combination of refastenable and releasable
bond. One version of the present invention includes a prefastened
article, including a chassis including a first waist region and a
second waist region, together defining a waist opening and first
and second leg openings. The article also includes a refastenable
seam joining a first distal portion of the first waist region to a
first distal portion of the second waist region. The refastenable
seam includes a first refastenable bond connecting the first distal
portion of the first waist region and the first distal portion of
the second waist region having a first refastenable bond peel
strength. The first distal portion of the first waist region is
folded and bonded with a releasable bond having a first releasable
bond peel strength. Further the first refastenable bond peel
strength is greater than the first releasable bond peel
strength.
[0006] Another version of the present invention provides a
refastenable, pant-like garment, including a chassis including a
first waist region and a second waist region, together defining a
waist opening and first and second leg openings. The garment also
includes a first refastenable seam joining a first distal portion
of the first waist region to a first distal portion of the second
waist region. The first refastenable seam includes a first
refastenable bond connecting the first distal portion of the first
waist region and the first distal portion of the second waist
region having a first refastenable bond peel strength. The first
distal portion of the first waist region being folded and bonded
with a releasable bond having a first releasable bond peel
strength. Further the first refastenable bond peel strength is
greater than the first releasable bond peel strength. The garment
also includes a second refastenable seam joining a second distal
portion of the first waist region to a second distal portion of the
second waist region. The second refastenable seam includes a second
refastenable bond connecting the second distal portion of the first
waist region and the second distal portion of the second waist
region having a second refastenable bond peel strength. The second
distal portion of the first waist region being folded and bonded
with a releasable bond having a second releasable bond peel
strength. Further the second refastenable bond peel strength is
greater than the second releasable bond peel strength. Still
another version of the present invention includes a refastenable
joint joining a first material having a first end and a second end
to a second material having a third end and a fourth end. The
refastenable joint including a refastenable bond connecting the
first end to the third end. The first material is folded and bonded
with a releasable bond. Further separating the second end from the
fourth end initially stresses the refastenable bond and the
releasable bond predominantly in peel, then ruptures the releasable
bond predominantly in peel, then stresses the refastenable bond
predominantly in shear.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of an absorbent garment having
refastenable side seams;
[0008] FIG. 2 is a plan view of an absorbent garment in a stretched
flat state showing the surface of the garment that faces away from
the wearer when the garment is worn;
[0009] FIG. 3 is a plan view of an absorbent garment in a stretched
flat state showing the surface of the garment that faces the wearer
when the garment is worn, and with portions cut away to show the
underlying features;
[0010] FIGS. 4 and 4A illustrate top views of a waist region of an
absorbent garment illustrating a first version of refastenable
seams of the present invention;
[0011] FIGS. 5 and 5A illustrate top views of a waist region of an
absorbent garment illustrating a second version of refastenable
seams of the present invention;
[0012] FIGS. 6A-6D illustrate several seams joining a first
material to a second material 116.
DEFINITIONS
[0013] Within the context of this specification, each term or
phrase below will include the following meaning or meanings.
[0014] "Attached" refers to the joining, adhering, connecting,
bonding, or the like, of at least two elements. Two elements will
be considered to be attached to one another when they are attached
directly to one another or indirectly to one another, such as when
each is directly connected to intermediate elements.
[0015] "Bonded" refers to the joining, adhering, connecting,
attaching, or the like, of at least two elements. Two elements will
be considered to be bonded together when they are bonded directly
to one another or indirectly to one another, such as when each is
directly bonded to intermediate elements.
[0016] "Elastomeric" and "elastic" refer to that property of a
material or composite by virtue of which it tends to recover its
original size and shape after removal of a force causing a
deformation. It is generally preferred that the elastomeric
material or composite be capable of being elongated by at least 50
percent, more preferably by at least 300 percent, of its relaxed
length and recover, upon release of an applied force, at least 50
percent of its elongation.
[0017] "Film" refers to a thermoplastic film made using a film
extrusion process, such as a cast film or blown film extrusion
process. The term includes apertured films, slit films, and other
porous films which constitute liquid transfer films, as well as
films which do not transfer liquid.
[0018] "Hydrophilic" describes fibers or the surfaces of fibers
which are wetted by the aqueous liquids in contact with the fibers.
The degree of wetting of the materials can, in turn, be described
in terms of the contact angles and the surface tensions of the
liquids and materials involved. Equipment and techniques suitable
for measuring the wettability of particular fiber materials or
blends of fiber materials can be provided by a Cahn SFA-222 Surface
Force Analyzer System, or a substantially equivalent system. When
measured with this system, fibers having contact angles less than
90 are designated "wettable" or hydrophilic, while fibers having
contact angles greater than 90 are designated "nonwettable" or
hydrophobic.
[0019] "Layer" when used in the singular can have the dual meaning
of a single element or a plurality of elements.
[0020] "Liquid impermeable," when used in describing a layer or
multi-layer laminate, means that a liquid, such as urine, will not
pass through the layer or laminate, under ordinary use conditions,
in a direction generally perpendicular to the plane of the layer or
laminate at the point of liquid contact.
[0021] "Liquid permeable material" or "liquid water-permeable
material" refers to a material present in one or more layers, such
as a film, nonwoven fabric, or open-celled foam, which is porous,
and which is water permeable due to the flow of water and other
aqueous liquids through the pores. The pores in the film or foam,
or spaces between fibers or filaments in a nonwoven web, are large
enough and frequent enough to permit leakage and flow of liquid
water through the material.
[0022] "Longitudinal" and "transverse" have their customary
meaning, as indicated by the longitudinal and transverse axes
depicted in FIGS. 2 and 3. The longitudinal axis lies in the plane
of the article and is generally parallel to a vertical plane that
bisects a standing wearer into left and right body halves when the
article is worn. The transverse axis lies in the plane of the
article generally perpendicular to the longitudinal axis. The
article as illustrated is generally longer in the longitudinal
direction than in the transverse direction, although products
longer in the transverse direction are also possible.
[0023] "Longitudinal midline" refers to a line, either real or
imaginary, that runs along the longitudinal length of the chassis
of an absorbent garment and bisects the chassis into two halves of
equal transverse width.
[0024] "Meltblown fiber" means fibers formed by extruding a molten
thermoplastic material through a plurality of fine, usually
circular, die capillaries as molten threads or filaments into
converging high velocity heated gas (e.g., air) streams which
attenuate the filaments of molten thermoplastic material to reduce
their diameter, which may be to microfiber diameter. Thereafter,
the meltblown fibers are carried by the high velocity gas stream
and are deposited on a collecting surface to form a web of randomly
dispersed meltblown fibers. Such a process is disclosed for
example, in U.S. Pat. No. 3,849,241 to Butin et al. Meltblown
fibers are microfibers which may be continuous or discontinuous,
are generally smaller than about 0.6 denier, and are generally self
bonding when deposited onto a collecting surface. Meltblown fibers
used in the present invention are preferably substantially
continuous in length.
[0025] "Member" when used in the singular can have the dual meaning
of a single element or a plurality of elements.
[0026] "Nonwoven" and "nonwoven web" refer to materials and webs of
material which are formed without the aid of a textile weaving or
knitting process.
[0027] "Offset tucked" refers to a folded position of a garment
wherein the front and back regions of the garment are skewed such
that the longitudinal midline of the front region of the chassis is
offset or not aligned with the longitudinal midline of the back
region of the chassis, and seams connecting the front and back
regions are tucked.
[0028] "Operatively joined," in reference to the attachment of an
elastic member to another element, means that the elastic member
when attached to or connected to the element, or treated with heat
or chemicals, by stretching, or the like, gives the element elastic
properties; and with reference to the attachment of a non-elastic
member to another element, means that the member and element can be
attached in any suitable manner that permits or allows them to
perform the intended or described function of the joinder. The
joining, attaching, connecting or the like can be either directly,
such as joining either member directly to an element, or can be
indirectly by means of another member disposed between the first
member and the first element.
[0029] "Permanently attached" or "permanently bonded" refers to the
joining, adhering, connecting, attaching, bonding, or the like, of
two elements of an absorbent garment such that the elements tend to
be and remain attached during normal use conditions of the
absorbent garment.
[0030] "Polymers" include, but are not limited to, homopolymers,
copolymers, such as for example, block, graft, random and
alternating copolymers, terpolymers, etc. and blends and
modifications thereof. Furthermore, unless otherwise specifically
limited, the term "polymer" shall include all possible geometrical
configurations of the material. These configurations include, but
are not limited to isotactic, syndiotactic and atactic
symmetries.
[0031] "Refastenable" refers to the property of two elements being
capable of releasable attachment, separation, and subsequent
releasable reattachment without substantial permanent deformation
or rupture. The refastenable elements can be attached, separated
and reattached for at least one cycle, suitably for at least 5
cycles, or suitably for at least 10 cycles.
[0032] "A Releasable bond" and variations thereof refer to two
elements being connected or connectable such that the elements tend
to remain connected absent a separation force applied to one or
both of the elements. The required separation force is typically
less than that encountered while wearing the absorbent garment.
[0033] "Self-engaging fastener" refers to a fastening component
that can engage with another fastening component having the same
structure.
[0034] "Spunbonded fiber" refers to small diameter fibers which are
formed by extruding molten thermoplastic material as filaments from
a plurality of fine capillaries of a spinnerette having a circular
or other configuration, with the diameter of the extruded filaments
then being rapidly reduced as by, for example, in U.S. Pat. No.
4,340,563 to Appel et al., and U.S. Pat. No. 3,692,618 to Dorschner
et al., U.S. Pat. No. 3,802,817 to Matsuki et al., U.S. Pat. Nos.
3,338,992 and 3,341,394 to Kinney, U.S. Pat. No. 3,502,763 to
Hartmann, U.S. Pat. No. 3,502,538 to Petersen, and U.S. Pat. No.
3,542,615 to Dobo et al., each of which is incorporated herein in
its entirety by reference. Spunbond fibers are quenched and
generally not tacky when they are deposited onto a collecting
surface. Spunbond fibers are generally continuous and often have
average deniers larger than about 0.3, more particularly, between
about 0.6 and 10.
[0035] "Stretchable" means that a material can be stretched,
without breaking, to at least 150% of its initial (unstretched)
length in at least one direction, suitably to at least 250% of its
initial length, desirably to at least 300% of its initial
length.
[0036] "Superabsorbent" or "superabsorbent material" refers to a
water-swellable, water-insoluble organic or inorganic material
capable, under the most favorable conditions, of absorbing at least
about 15 times its weight and, more desirably, at least about 30
times its weight in an aqueous solution containing 0.9 weight
percent sodium chloride. The superabsorbent materials can be
natural, synthetic and modified natural polymers and materials. In
addition, the superabsorbent materials can be inorganic materials,
such as silica gels, or organic compounds such as cross-linked
polymers.
[0037] "Surface" includes any layer, film, woven, nonwoven,
laminate, composite, or the like, whether pervious or impervious to
air, gas, and/or liquids.
[0038] "Thermoplastic" describes a material that softens when
exposed to heat and which substantially returns to a nonsoftened
condition when cooled to room temperature.
[0039] These terms may be defined with additional language in the
remaining portions of the specification.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0040] The present invention is directed to refastenable seams on
garments. The principles of the present invention can be
incorporated into any suitable disposable absorbent article having
a pre-fastened and refastenable seam. Examples of such suitable
articles include diapers, training pants, incontinence products,
other personal care or health care garments, including medical
garments, or the like. As used herein, the term "incontinence
products" includes absorbent underwear for children, absorbent
garments for children or young adults with special needs such as
autistic children or others with bladder/bowel control problems as
a result of physical disabilities, as well as absorbent garments
for incontinent older adults. For ease of explanation, the
description hereafter will be in terms of a child's training
pant.
[0041] Referring to FIG. 1, the training pant 20 includes an
absorbent chassis 32 defining a front region 22, a back region 24,
a crotch region 26 interconnecting the front and back regions, an
inner surface 28 which is configured to contact the wearer, and an
outer surface 30 opposite the inner surface which is configured to
contact the wearer's clothing. With additional reference to FIGS. 2
and 3, the absorbent chassis 32 also defines a pair of transversely
opposed distal edges 36 and a pair of longitudinally opposed waist
edges, which are designated front waist edge 38 and back waist edge
39. The front region 22 is contiguous with the front waist edge 38,
and the back region 24 is contiguous with the back waist edge 39.
The chassis 32 also includes a pair of transversely opposed front
side panels 34 and a pair of transversely opposed back side panels
134. The front and back side panels 34, 134 are formed along the
distal edges 36 of the chassis and can either be integrally formed
with the chassis, as shown in FIG. 2, or can each include at least
one separate element permanently attached to the chassis, as shown
in FIGS. 1 and 3. For reference, arrows 48 and 49 depicting the
orientation of the longitudinal axis and the transverse axis,
respectively, of the training pant 20 are illustrated in FIGS. 2
and 3.
[0042] The illustrated absorbent chassis 32 can include an outer
cover 40, a bodyside liner 42 which is connected to the outer cover
in a superposed relation, an absorbent assembly 44 which is located
between the outer cover 40 and the bodyside liner 42, and a pair of
containment flaps 46, as shown in FIG. 3.
[0043] With the training pant 20 in the fastened position, as
partially illustrated in FIG. 1, the front and back regions 22 and
24 are joined together to define a three-dimensional pant
configuration having a waist opening 50 and a pair of leg openings
52. The front region 22 includes the portion of the training pant
20 which, when worn, is positioned on the front of the wearer while
the back region 24 includes the portion of the training pant which,
when worn, is positioned on the back of the wearer. The crotch
region 26 of the training pant 20 includes the portion of the
training pant which, when worn, is positioned between the legs of
the wearer and covers the lower torso of the wearer. The front and
back side panels 34, 134 include the portions of the training pant
20 which, when worn, are positioned on the hips of the wearer.
[0044] As shown in FIG. 3, the front region 22 of the absorbent
chassis 32 includes the transversely opposed front side panels 34
and a front panel 35 positioned between and interconnecting the
side panels, along with a front waist elastic member 54 and any
other connected components. A front waist region 90 is a region of
the front panel 35 along the front waist edge 38. The back region
24 of the absorbent chassis 32 includes the transversely opposed
back side panels 134 and a back panel 135 positioned between and
interconnecting the side panels, as well as a rear waist elastic
member 56 and any other connected components. A back waist region
92 is a region of the back panel 135 along the back waist edge 39.
The waist edges 38 and 39 of the absorbent chassis 32 are
configured to encircle the waist of the wearer when worn and
provide the waist opening 50 which defines a waist perimeter
dimension. Portions of the transversely opposed distal edges 36 of
the chassis 32 in the crotch region 26, along with leg end edges 70
of the side panels 34 and 134, generally define the leg openings
52.
[0045] The absorbent chassis 32 is configured to contain and/or
absorb any body exudates discharged from the wearer. For example,
the absorbent chassis 32 desirably, although not necessarily,
includes the pair of containment flaps 46 which are configured to
provide a barrier to the transverse flow of body exudates. A flap
elastic member 53 (FIG. 3) can be operatively joined with each
containment flap 46 in any suitable manner as is well known in the
art. The elasticized containment flaps 46 define an unattached edge
which assumes an upright, generally perpendicular configuration in
at least the crotch region 26 of the training pant 20 to form a
seal against the wearer's body. The containment flaps 46 can be
located along the transversely opposed distal edges 36 of the
absorbent chassis 32, and can extend longitudinally along the
entire length of the absorbent chassis or may only extend partially
along the length of the absorbent chassis. Suitable constructions
and arrangements for the containment flaps 46 are generally well
known to those skilled in the art and are described in U.S. Pat.
No. 4,704,116 issued Nov. 3, 1987 to Enloe, which is incorporated
herein by reference.
[0046] To further enhance containment and/or absorption of body
exudates, the training pant 20 can include the front waist elastic
member 54, the rear waist elastic member 56, and leg elastic
members 58, as are known to those skilled in the art (FIG. 3). The
waist elastic members 54 and 56 can be operatively joined to the
outer cover 40 and/or bodyside liner 42 along the opposite waist
edges 38 and 39 as well as over waist edges 72 of the side panels
34, 134, and can extend over part or all of the waist edges. The
leg elastic members 58 can be operatively joined to the outer cover
40 and/or bodyside liner 42 while longitudinally aligned along the
distal edges 36 and positioned in the crotch region 26 of the
chassis 32.
[0047] The flap elastic members 53, the waist elastic members 54
and 56, and the leg elastic members 58 can be formed of any
suitable elastic material. As is well known to those skilled in the
art, suitable elastic materials include sheets, strands or ribbons
of natural rubber, synthetic rubber, or thermoplastic elastomeric
polymers. The elastic materials can be stretched and adhered to a
substrate, adhered to a gathered substrate, or adhered to a
substrate and then elasticized or shrunk, for example with the
application of heat; such that elastic constrictive forces are
imparted to the substrate. In one particular embodiment, for
example, the leg elastic members 58 include a plurality of dry-spun
coalesced multifilament spandex elastomeric threads sold under the
trade name LYCRA.RTM. and available from E.I. DuPont de Nemours and
Company, Wilmington, Del., U.S.A.
[0048] The outer cover 40 desirably includes a material that is
substantially liquid impermeable, and can be elastic, stretchable
or nonstretchable. The outer cover 40 can be a single layer of
liquid impermeable material, but desirably includes a multi-layered
laminate structure in which at least one of the layers is liquid
impermeable. For instance, the outer cover 40 can include a liquid
permeable outer layer and a liquid impermeable inner layer that are
suitably joined together thermally, ultrasonically, by a laminate
adhesive, or by any other suitable methods known in the art.
Suitable laminate adhesives, which can be applied continuously or
intermittently as beads, a spray, parallel swirls, or the like, can
be obtained from Findley Adhesives, Inc., of Wauwatosa, Wis.,
U.S.A., or from National Starch and Chemical Company, Bridgewater,
N.J., U.S.A. The liquid permeable outer layer can be any suitable
material and desirably one that provides a generally cloth-like
texture and/or mating fastening component qualities. One example of
such a material is a 20 gsm (grams per square meter) spunbond
polypropylene nonwoven web. The outer layer may also be made of
those materials of which liquid permeable bodyside liner 42 is
made. While it is not a necessity for the outer layer to be liquid
permeable, it is desired that it provides a relatively cloth-like
texture to the wearer.
[0049] The inner layer of the outer cover 40 can be both liquid and
vapor impermeable, or can be liquid impermeable and vapor
permeable. The inner layer is desirably manufactured from a thin
plastic film, although other flexible liquid impermeable materials
may also be used. The inner layer, or the liquid impermeable outer
cover 40 when a single layer, prevents waste material from wetting
articles, such as bedsheets and clothing, as well as the wearer and
care giver. A suitable liquid impermeable film for use as a liquid
impermeable inner layer, or a single layer liquid impermeable outer
cover 40, is a 0.2 millimeter polyethylene film commercially
available from Huntsman Packaging of Newport News, Va., U.S.A. If
the outer cover 40 is a single layer of material, it can be
embossed and/or matte finished to provide a more cloth-like
appearance. As earlier mentioned, the liquid impermeable material
can permit vapors to escape from the interior of the disposable
absorbent article, while still preventing liquids from passing
through the outer cover 40. A suitable "breathable" material is
composed of a microporous polymer film or a nonwoven fabric that
has been coated or otherwise treated to impart a desired level of
liquid impermeability. A suitable microporous film is a PMP-1 film
material commercially available from Mitsui Toatsu Chemicals, Inc.,
Tokyo, Japan, or an XKO-8044 polyolefin film commercially available
from 3M Company, Minneapolis, Minn.
[0050] The liquid permeable bodyside liner 42 is illustrated as
overlying the outer cover 40 and absorbent assembly 44, and may but
need not have the same dimensions as the outer cover 40. The
bodyside liner 42 is desirably compliant, soft feeling, and
non-irritating to the child's skin. Further, the bodyside liner 42
can be less hydrophilic than the absorbent assembly 44, to present
a relatively dry surface to the wearer and permit liquid to readily
penetrate through its thickness. As mentioned, the bodyside liner
42 and/or the outer cover 40 can be made of a fastening component
material or a mating fastening component material to eliminate the
need for separately attached mating fastening components.
[0051] The bodyside liner 42 can be manufactured from a wide
selection of web materials, such as synthetic fibers (for example,
polyester or polypropylene fibers), natural fibers (for example,
wood or cotton fibers), a combination of natural and synthetic
fibers, porous foams, reticulated foams, apertured plastic films,
or the like. Various woven and nonwoven fabrics can be used for the
bodyside liner 42. For example, the bodyside liner can be composed
of a meltblown or spunbonded web of polyolefin fibers. The bodyside
liner can also be a bonded-carded web composed of natural and/or
synthetic fibers. The bodyside liner can be composed of a
substantially hydrophobic material, and the hydrophobic material
can, optionally, be treated with a surfactant or otherwise
processed to impart a desired level of wettability and
hydrophilicity. For example, the material can be surface treated
with about 0.45 weight percent of a surfactant mixture including
AHCOVEL.RTM. N-62 from Uniqema, Inc., a division of ICI of New
Castle, Del., and GLUCOPON.RTM. 220UP from Cognis Corp. of Ambler,
Pa., in an active ratio of 3:1. The surfactant can be applied by
any conventional means, such as spraying, printing, brush coating
or the like. The surfactant can be applied to the entire bodyside
liner 42 or can be selectively applied to particular sections of
the bodyside liner, such as the medial section along the
longitudinal centerline.
[0052] A suitable liquid permeable bodyside liner 42 is a nonwoven
bicomponent web having a basis weight of about 27 gsm. The nonwoven
bicomponent can be a spunbond bicomponent web, or a bonded carded
bicomponent web. Suitable bicomponent staple fibers include a
polyethylene/polypropylene bicomponent fiber available from CHISSO
Corporation, Osaka, Japan. In this particular bicomponent fiber,
the polypropylene forms the core and the polyethylene forms the
sheath of the fiber. Other fiber orientations are possible, such as
multi-lobe, side-by-side, end-to-end, or the like. While the outer
cover 40 and bodyside liner 42 can include elastomeric materials,
it can be desirable in some embodiments for the composite structure
to be generally inelastic, where the outer cover, the bodyside
liner and the absorbent assembly include materials that are
generally not elastomeric.
[0053] The absorbent assembly 44 (FIG. 3) is positioned between the
outer cover 40 and the bodyside liner 42, which components can be
joined together by any suitable means, such as adhesives, as is
well known in the art. The absorbent assembly 44 can be any
structure which is generally compressible, conformable,
non-irritating to the child's skin, and capable of absorbing and
retaining liquids and certain body wastes. The absorbent assembly
44 can be manufactured in a wide variety of sizes and shapes, and
from a wide variety of liquid absorbent materials commonly used in
the art. For example, the absorbent assembly 44 can suitably
include a matrix of hydrophilic fibers, such as a web of cellulosic
fluff, mixed with particles of a high-absorbency material commonly
known as superabsorbent material. High absorbency material can be
provided in any form known in the art, including but not limited to
particles, fibers, foams and films.
[0054] In a particular embodiment, the absorbent assembly 44
includes a matrix of cellulosic fluff, such as wood pulp fluff, and
superabsorbent hydrogel-forming particles. The wood pulp fluff can
be exchanged with synthetic, polymeric, meltblown fibers or with a
combination of meltblown fibers and natural fibers. The
superabsorbent particles can be substantially homogeneously mixed
with the hydrophilic fibers or can be nonuniformly mixed. The fluff
and superabsorbent particles can also be selectively placed into
desired zones of the absorbent assembly 44 to better contain and
absorb body exudates. The concentration of the superabsorbent
particles can also vary through the thickness of the absorbent
assembly 44. Alternatively, the absorbent assembly 44 can include a
laminate of fibrous webs and superabsorbent material or other
suitable means of maintaining a superabsorbent material in a
localized area.
[0055] Suitable superabsorbent materials can be selected from
natural, synthetic, and modified natural polymers and materials.
The superabsorbent materials can be inorganic materials, such as
silica gels, or organic compounds, such as crosslinked polymers.
Suitable superabsorbent materials are available from various
commercial vendors, such as Dow Chemical Company located in
Midland, Mich., U.S.A., and Stockhausen GmbH & Co. KG, D-47805
Krefeld, Federal Republic of Germany. Typically, a superabsorbent
material is capable of absorbing at least about 15 times its weight
in water, and desirably is capable of absorbing more than about 25
times its weight in water.
[0056] In one embodiment, the absorbent assembly 44 is generally
rectangular in shape, and includes a blend of wood pulp fluff and
superabsorbent material. One preferred type of fluff is identified
with the trade designation CR1654, available from U.S. Alliance,
Childersburg, Ala., U.S.A., and is a bleached, highly absorbent
sulfate wood pulp containing primarily soft wood fibers. As a
general rule, the superabsorbent material is present in the
absorbent assembly 44 in an amount of from about 0 to about 90
weight percent based on total weight of the absorbent assembly. The
absorbent assembly 44 suitably has a density within the range of
about 0.10 to about 0.50 grams per cubic centimeter. The absorbent
assembly 44 may or may not be wrapped or encompassed by a suitable
tissue wrap that maintains the integrity and/or shape of the
absorbent assembly.
[0057] The absorbent chassis 32 can also incorporate other
materials that are designed primarily to receive, temporarily
store, and/or transport liquid along the mutually facing surface
with the absorbent assembly 44, thereby maximizing the absorbent
capacity of the absorbent assembly. One suitable material is
referred to as a surge layer (not shown) and includes a material
having a basis weight of about 50 to about 120 grams per square
meter, and including a through-air-bonded-carded web of a
homogenous blend of 60 percent 3 denier type T-256 bicomponent
fiber including a polyester core/polyethylene sheath and 40 percent
6 denier type T-295 polyester fiber, both commercially available
from Kosa Corporation of Salisbury, N.C., U.S.A.
[0058] As noted previously, the illustrated training pant 20 has
front and back side panels 34, 134 disposed on each side of the
absorbent chassis 32. These transversely opposed front side panels
34 and transversely opposed back side panels 134 can be permanently
bonded to the front panel 35 and back panel 135 in the respective
front and back regions 22, 24 along attachment lines 66, and are
attached to one another. The side panels 34, 134 may be permanently
attached using attachment means known to those skilled in the art
such as adhesive, thermal or ultrasonic bonding. As mentioned, the
side panels 34, 134 can also be formed as continuous extensions of
the front and back panels 35, 135.
[0059] As shown in FIG. 1, the fastening component 82 can be
permanently bonded to either the inner surface 28 or the outer
surface 30 of each front side panel 34 adjacent each distal edge 36
of the front region 22 of the chassis 32, and the mating fastening
components 84 can be permanently bonded to either the inner surface
28 or the outer surface 30 of each back side panel 134 adjacent
each distal edge 36 of the back region 24 of the chassis, or either
the inner surface 28 or the outer surface 30 of the chassis 32 can
include fastening material 86 or mating fastening material 88. The
fastening components 82 and the mating fastening components 84 may
be attached to the side panels 34 and the chassis 32 using
attachment means known to those skilled in the art such as
adhesive, thermal or ultrasonic bonding.
[0060] The fastening component may comprise adhesive, cohesive,
tape, hook and loop, or any other refastenable attachment means
know in the art. In one particular embodiment, the fastening
components 82 each include hook type fasteners and the mating
fastening components 84 each include complementary loop type
fasteners. In another particular embodiment, the fastening
components 82 each include loop type fasteners and the mating
fastening components 84 each include complementary hook type
fasteners. In yet another embodiment, half of the fastening
components 82 and half of the mating fastening components 84 can
include hook type fasteners, while half of the fastening components
82 and half of the mating fastening components 84 can include loop
type fasteners. In still another embodiment, each of the fastening
components 82 and the mating fastening components 84 include
self-engaging fasteners. The fastening components 82 and the mating
fastening components 84 are desirably rectangular, although they
may alternatively be square, round, oval, curved, discontinuous
such as multiple fasteners, or any other suitable shape. The
fastening components 82 and mating fastening components 84 may or
may not be parallel to a longitudinal midline 94 of the garment
20.
[0061] In another embodiment, the nonwoven web in the outer cover
40 can be constructed of a material that is suitable for use as a
loop-type fastening material, thereby eliminating the need for
separate loop-type fastening components 82 or 84, and the fastening
components 82 or 84 on the side panels 34 or 134 can be hook-type
fastening components. In yet another embodiment, the nonwoven web
in the bodyside liner 42 can be constructed of a material that is
suitable for use as a loop-type fastening material, thereby
eliminating the need for separate loop-type fastening components 82
or 84, and the fastening components 82 or 84 on the side panels 34
or 134 can be hook-type fastening components. In still another
embodiment, an inner or outer surface of either the front side
panels 34 or the back side panels 134 can include a loop-type
fastening material, thereby eliminating the need for separate loop
type fastening components 82 or 84.
[0062] Loop type fasteners typically include a fabric or material
having a base or backing structure and a plurality of loop members
extending upwardly from at least one surface of the backing
structure. The loop material can be formed of any suitable
material, such as acrylic, nylon or polyester, and can be formed by
methods such as warp knitting, stitch bonding or needle punching.
Suitable loop materials are available from Guilford Mills, Inc.,
Greensboro, N.C., U.S.A. under the trade designation No. 36549.
[0063] Hook type fasteners typically include a fabric or material
having a base or backing structure and a plurality of hook members
extending upwardly from at least one surface of the backing
structure. In contrast to the loop type fasteners which desirably
include a flexible fabric, the hook material advantageously
includes a resilient material to minimize unintentional
disengagement of the fastener components as a result of the hook
material becoming deformed and catching on clothing or other items.
Suitable hook material can be molded or extruded of nylon,
polypropylene or another suitable material. Suitable single-sided
hook materials for the fastening components 82 or the mating
fastening components 84 are available from commercial vendors such
as Velcro Industries B.V., Amsterdam, Netherlands or affiliates
thereof, and are identified as Velcro HTH-829 with a
uni-directional hook pattern and having a thickness of about 0.9
millimeters (35 mils) and HTH-851 with a uni-directional hook
pattern and having a thickness of about 0.5 millimeters (20 mils);
and Minnesota Mining & Manufacturing Co., St. Paul, Minn.
U.S.A., including specific materials identified as CS-600.
[0064] In particular embodiments for improved fit and appearance,
the side panels 34, 134 desirably have an average length dimension
measured parallel to the longitudinal axis 48 that is about 15
percent or greater, and particularly about 25 percent or greater,
of the overall length dimension of the absorbent article, also
measured parallel to the longitudinal axis 48. For example, in
training pants having an overall length dimension of about 54
centimeters, the side panels 34, 134 desirably have an average
length dimension of about 10 centimeters or greater, such as about
15 centimeters. A waist end edge 72 of each side panel 34, 134 can
suitably be relatively straight across in the transverse direction
while the leg end edge 70 of each side panel 34, 134 can suitably
have a curvature, as shown in FIGS. 2 and 3, to allow the leg
opening 52 to conform about a wearer's leg.
[0065] Each of the side panels 34, 134 can include one or more
individual, distinct pieces of material in addition to the
fastening components 82, 84, as shown in FIG. 3. In particular
embodiments, for example, each side panel 34, 134 can include first
and second side panel portions that are joined at a seam, with at
least one of the portions including an elastomeric material. The
side panels 34, 134 desirably include an elastic material capable
of stretching in a direction generally parallel to the transverse
axis 49 of the training pant 20. The front side panels 34 and the
back side panels 134 can be of equal widths or of different widths
in the transverse direction.
[0066] Suitable elastic materials, as well as one described process
of incorporating elastic side panels into a training pant, are
described in the following U.S. Pat. No. 4,940,464 issued Jul. 10,
1990 to Van Gompel et al.; U.S. Pat. No. 5,224,405 issued Jul. 6,
1993 to Pohjola; U.S. Pat. No. 5,104,116 issued Apr. 14, 1992 to
Pohjola; and U.S. Pat. No. 5,046,272 issued Sep. 10, 1991 to Vogt
et al.; all of which are incorporated herein by reference. In
particular embodiments, the elastic material includes a
stretch-thermal laminate (STL), a neck-bonded laminated (NBL), a
reversibly necked laminate, or a stretch-bonded laminate (SBL)
material. Methods of making such materials are well known to those
skilled in the art and described in U.S. Pat. No. 4,663,220 issued
May 5, 1987 to Wisneski et al.; U.S. Pat. No. 5,226,992 issued Jul.
13, 1993 to Morman; and U.S. Pat. No. 4,720,415 issued Feb. 2, 1992
to Taylor et al.; all of which are incorporated herein by
reference. Alternatively, the side panel material may include other
woven or nonwoven materials, such as those described above as being
suitable for the outer cover 40 or bodyside liner 42, or
stretchable but inelastic materials.
[0067] FIG. 4 illustrates a view of a training pant 20 including a
refastenable bond 83 and a releasable bond 96 of the present
invention. The training pant 20 includes a fastening component 82
disposed in a first waist region, specifically as shown attached to
the front side panel 34. The training pant 20 also includes a
mating fastening component 84 disposed in the second waist region,
specifically as shown attached to the back side panel 134. The
fastening components 82, 84 define a refastenable bond 83. The
training pant 20 also includes a releasable bond 96, which bonds a
portion of the front side panel 34 to a second portion of the front
side panel 34 maintaining a fold 102 in the front side panel 34.
The fold 102 and releasable bond 96 are positioned such that the
fastening component 82, while disposed on the outer surface of the
front panel 34, faces the inner surface 28 of the back side panel
134.
[0068] This arrangement of bonds 83, 96 and fold 102 may provide
many benefits, first of which may be ease of manufacture. During
manufacture, the training pant 20 may be constructed from a flat
elongated web. The releasable front side panel 34 may be folded and
releasably bonded 96. The fastening components 82, 84 may then be
placed on the side panels 34, 134 (both applied from the inner
surface 28 side of the elongated web). The elongate web may then be
cut into discrete articles. To form the closed training pant 20,
the discrete article is folded along the transverse axis 49
bringing the front side panel 34 and rear side panel 134 into face
to face contact, forming a refastenable bond 83 with the fastening
components 82, 84.
[0069] FIG. 4A illustrates a view of a training pant 20 including a
refastenable bond 83 and a releasable bond 96 of the present
invention after the front waist region 90 has been separated from
the back waist region 92. As illustrated in FIG. 4, separating the
front waist region 90 from the back waist region 92 initially
stresses the refastenable bond 83 and the releasable bond 96
predominantly in peel. Further separation of the waist regions 92,
94 ruptures the releasable bond 96 predominantly in peel
(releasable bond after rupture 100). Continued separation of the
waist region 92, 94, stresses the refastenable bond 83
predominantly in shear. The arrangement of the releasable bond 96,
refastenable bond 83 and fold 102, may provide great benefits in
the manufacture, strength and aesthetics of refastenable bond
83.
[0070] One way to construct the combination of side panels 34, 134
is by utilizing bonds 82, 84, 96 with the appropriate relative peel
strengths. The peel strength of the refastenable bond 83 may be
chosen to be greater than the peel strength of the releasable bond
96. The ratio of the refastenable bond peel strength to the
releasable bond peel strength may be greater than 1.5,
alternatively greater than 5, alternatively greater than 10,
alternatively greater than 25, alternatively greater than 50.
[0071] The releasable bond 96 may include ultrasonic bonding,
pressure bonding, thermal bonding, adhesive bonding, cohesive
bonding, magnetic bonding or any combination thereof. The
releasable bond 96 may also include hook and loop. The releasable
bond 96 may be chosen such the releasable bond after rupture 100 is
skin friendly as contact with a wearer's skin is possible.
[0072] Peel Strength Test
[0073] This procedure is a tensile bench test to measure the peel
force required to separate a mechanical fastening system that joins
two materials. The peel force of separation is measured by
determining load values as the two materials are pulled apart
perpendicular to their plane of contact. The direction of removal
(peel), in this application, is that direction in which the
fastener material would generally be removed from a substrate when
the product is in use. Peel strength is normalized by dividing by
the contact area resulting in a force per area.
[0074] Equipment
[0075] 1. Tensile tester capable of obtaining a peak load and
equipped with an appropriate load cell. A suitable tensile testing
system is a Sintech Tensile Tester, commercially available from MTS
Sintech, Research Triangle Park, N.C., under the trade designation
Instron Model 4201 Tensile Tester with Sintech QAD (Quality
Assurance Department) Software.
[0076] 2. Software commercially obtained from MTS Sintech under the
trade designation Sintech Testworks.RTM..
[0077] 3. Pneumatic-action grips commercially available from
Instron Corporation, Canton, Mass., under the trade designation
"Instron Model 2712-004."
[0078] 4. 1 by 4 inch grip faces, serrated, commercially available
from Instron Corporation, Canton, Mass.
[0079] 5. Test facility having a temperature of 23.+-.1.degree. C.,
and a relative humidity of 50.+-.2 percent.
[0080] Test Procedure
[0081] 1. A sample to be tested is conditioned in the test facility
for at least 4 hours prior to testing.
[0082] 2. The load cell is calibrated and the software loaded.
[0083] 3. The grips are installed on the tensile tester with the
jaws closed.
[0084] 4. The test condition for the tensile tester is set as
follows:
[0085] Crosshead speed=500 millimeters/minute
[0086] Full-scale load=5 kilograms;
[0087] Threshold=5 percent;
[0088] Fail criterion=95 percent; and
[0089] Gage length=50 millimeters.
[0090] 5. The weight of the clamp is tared out.
[0091] 6. The ear portion on the back waist region of the article
is inserted into the upper jaw such that the edge of the grip face
is flush with the inner edge of the fastener material.
[0092] 7. The front waist region of the article is inserted into
the lower jaw such that the inner surface of the back waist region
and the outer surface of the front waist region form a 180.degree.
angle. The lower jaw is closed.
[0093] 8. The crosshead is started in motion.
[0094] 9. The peak load of failure is recorded. It is intended that
the mode of failure is that the back waist region of the diaper
separates from the front waist region of the diaper.
[0095] FIG. 5 illustrates a view of a training pant 20 including a
refastenable bond 83, permanent bond 98 and a releasable bond 96 of
the present invention. The training pant 20 includes a fastening
component 82 attached to the chassis and disposed in a first waist
region, specifically as shown attached to the front side panel 34.
The training pant 20 also includes a mating fastening component 84
attached to the chassis and disposed in the second waist region,
specifically as shown attached to the back side panel 134. The
fastening components 82, 84 define a refastenable bond 83. The
training pant 20 also includes a releasable bond 96, which bonds a
portion of the front side panel 34 to a second portion of the front
side panel 34 maintaining a fold 102 in the front side panel 34.
The fold 100 and releasable bond 96 are positioned such that the
fastening component 82, while disposed on the outer surface of the
front panel 34, faces the inner surface 28 of the back side panel
134. The training pant 20 also includes a permanent bond 98, which
bonds a portion of the back side panel 134 to a second portion of
the back side panel 134 maintaining a fold 104 in the back side
panel 134. The fold 104 and permanent bond 98 are positioned such
that the fastening component 84, while disposed on the outer
surface 30 of the back panel 134, faces the inner surface 28 of the
front side panel 34.
[0096] The inclusion of the permanent bond 98 and fold 104 may
provide additional benefits with regard to manufacture. The
permanent bond 98 and fold 104 may be positioned such that width of
the back side band 134 is reduced by the same amount as the width
of the front side panel 34 is reduced by the releasable bond 96 and
fold 102. If original width of the side panels 34, 134 is the same,
this equal reduction may simplify the manufacturing process by
aligning the fastening components 82, 84 when the training pant 20
is folded along the transverse axis 49 without further manipulation
of the side panels 34, 134.
[0097] FIG. 5A illustrates a view of a training pant 20 including a
refastenable bond 83, a permanent bond 98 and a releasable bond 96
of the present invention after the front waist region 90 has been
separated from the back waist region 92. As illustrated in FIG. 5,
separating the front waist region 90 from the back waist region 92
initially stresses the refastenable bond 83, the permanent bond 96
and the releasable bond 96 predominantly in peel. Further
separation of the waist regions 92, 94 ruptures the releasable bond
96 predominantly in peel (releasable bond after rupture 100).
Continued separation of the waist region 92, 94, stresses the
refastenable bond 83, and permanent bond 96 predominantly in shear.
The arrangement of the releasable bond 96, permanent bond 98,
refastenable bond 83, and folds 102, 104, may provide great
benefits in the manufacture, strength and aesthetics of releasable
seam 80. The permanent bond 98 and fold 104 provides the added
benefit in that the terminal end 106 of the back side panel 134 is
not visible from the outside of the training pant 20, thereby
presenting a more finished looking appearance.
[0098] The peel strength of the permanent bond 98 may be chosen to
be greater than the peel strength of the releasable bond 96. The
peel strength of the permanent bond 98 may be chosen to be greater
than the peel strength of the refastenable bond 83. The ratio of
the permanent bond peel strength to the releasable bond peel
strength may be greater than 1.5, alternatively greater than 5,
alternatively greater than 10, alternatively greater than 25,
alternatively greater than 50.
[0099] The permanent bond 98 may include ultrasonic bonding,
pressure bonding, thermal bonding, adhesive bonding, cohesive
bonding, magnetic bonding or any combination thereof. The permanent
bond 98 may also include hook and loop.
[0100] FIGS. 6A-D illustrate several seams joining a first material
110 having a first end 112 and a second end 114 and a second
material 116 having a third end 118 and fourth end 120,
specifically the first end 112 of the first material 110 to the
third end 118 of the second material 116. FIGS. 6A and 6B
illustrate butt seams. FIG. 6A illustrates a seam as previously
known in the art. As used herein, the term "butt seam" refers to a
seam or bond where the outer edges of the pieces of substrate
project inward or outward from the finished product, as opposed to
lying flat, thus placing the bond (122 in FIG. 6A, 122 and 124' in
FIG. 6B) in peel, as opposed to shearing strain. FIG. 6B
illustrates a combination of a refastenbable bond 122, and a
releasable bond 124 which join a first end 112 of a first material
110 to a third end 118 of a second material 116. The first material
110 is folded and bonded with the releasable bond 124.
[0101] Separating the second end 114 of the first material 110 from
the fourth end 120 of the second material 116 initially stresses
the refastenable bond 122 and the releasable bond 124 predominantly
in peel, then ruptures the releasable bond 124 predominantly in
peel, then stresses the refastenable bond 122 predominantly in
shear.
[0102] FIGS. 6B through 6D illustrate the conversion of a butt seam
into a lap seam. The releasable bond 124 has a lower peel strength
than refastenable bond 122; consequently, as force is applied to
the combination of bonds 122, 124, releasable bond 124 will fail
first. Upon failure of releasable bond 124, refastenable bond 124
is converted into a lap seam, thus placing the refastenable bond
124 in shear as opposed to peel strain.
[0103] It will be appreciated that details of the foregoing
embodiments, given for purposes of illustration, are not to be
construed as limiting the scope of this invention. Although only a
few exemplary embodiments of this invention have been described in
detail above, those skilled in the art will readily appreciate that
many modifications are possible in the exemplary embodiments
without materially departing from the novel teachings and
advantages of this invention. Accordingly, all such modifications
are intended to be included within the scope of this invention,
which is defined in the following claims and all equivalents
thereto. Further, it is recognized that many embodiments may be
conceived that do not achieve all of the advantages of some
embodiments, particularly of the preferred embodiments, yet the
absence of a particular advantage shall not be construed to
necessarily mean that such an embodiment is outside the scope of
the present invention.
* * * * *