U.S. patent application number 11/205831 was filed with the patent office on 2005-12-15 for multi-layer wiping device.
This patent application is currently assigned to The Procter & Gamble Company. Invention is credited to Benson, Douglas Herrin, Curro, John Joseph, Dugas, Michael Bernard, Strube, John Brian, Zink, Ronald Joseph II.
Application Number | 20050276956 11/205831 |
Document ID | / |
Family ID | 23195230 |
Filed Date | 2005-12-15 |
United States Patent
Application |
20050276956 |
Kind Code |
A1 |
Zink, Ronald Joseph II ; et
al. |
December 15, 2005 |
Multi-layer wiping device
Abstract
A multi-layer article having bonded first and second layers is
described herein. The first layer has two plies and a third
material disposed therebetween. The two plies are bonded together
at a plurality of discrete bond sites. Bonding the plies forms an
interior region between the plies. The second layer of the article
preferably comprises a cellulosic web.
Inventors: |
Zink, Ronald Joseph II;
(Blue Ash, OH) ; Dugas, Michael Bernard; (Wyoming,
OH) ; Curro, John Joseph; (Cincinnati, OH) ;
Benson, Douglas Herrin; (West Harrison, IN) ; Strube,
John Brian; (Okeana, OH) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
INTELLECTUAL PROPERTY DIVISION
WINTON HILL TECHNICAL CENTER - BOX 161
6110 CENTER HILL AVENUE
CINCINNATI
OH
45224
US
|
Assignee: |
The Procter & Gamble
Company
|
Family ID: |
23195230 |
Appl. No.: |
11/205831 |
Filed: |
August 17, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11205831 |
Aug 17, 2005 |
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10192372 |
Jul 10, 2002 |
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11205831 |
Aug 17, 2005 |
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PCT/US00/34746 |
Dec 20, 2000 |
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60308749 |
Jul 30, 2001 |
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Current U.S.
Class: |
428/198 ;
428/156; 428/172; 428/196; 428/72; 442/389; 442/392; 442/409 |
Current CPC
Class: |
Y10T 428/24331 20150115;
B32B 3/266 20130101; Y10T 428/2481 20150115; B32B 2262/062
20130101; D04H 1/559 20130101; Y10T 428/234 20150115; Y10T 442/671
20150401; B32B 7/04 20130101; Y10T 428/24942 20150115; Y10T
428/249939 20150401; Y10T 442/668 20150401; Y10T 428/24826
20150115; D04H 1/425 20130101; Y10T 442/69 20150401; Y10T 428/24322
20150115; Y10T 428/24612 20150115; Y10T 428/249924 20150401; Y10T
428/24479 20150115; B32B 5/26 20130101; Y10T 428/249921
20150401 |
Class at
Publication: |
428/198 ;
428/072; 428/156; 428/172; 428/196; 442/389; 442/392; 442/409 |
International
Class: |
B32B 003/00; B32B
005/06; B32B 005/26; B32B 027/02 |
Claims
What is claimed is:
1. A multi-layer article comprising a first layer and a second
layer bonded to each other; said first layer comprising a first
ply, a second ply joined to said first ply in a face-to-face
relationship at a plurality of discrete bond sites, said first and
second plies forming an interior region therebetween, and a third
material being disposed between said first and second plies, said
third material being differentiated from said first or second ply
by at least one material property selected from the group
consisting of thermal properties, elongation properties, elastic
properties, conductive properties, and combinations thereof, said
third material substantially filling said interior region; and,
said third material being apertured in regions coincident with said
bond sites, such that said first and second plies are joined
through said apertures.
2. The multi-layer article of claim 1 wherein said second layer
further comprises a cellulosic web.
3. The multi-layer article of claim 1 wherein said third material
of the said first layer is cellulosic.
4. The multi-layer article of claim 3 wherein the first layer and
the second layer are joined together at a predetermined pattern of
discrete bond sites.
5. The multi-layer article of claim 3 wherein the first and second
plies of the first layer are further comprised of thermoplastic
fibers and the first and second layers are thermally bonded without
the addition of an adhesive.
6. The multi-layer article of claim 5 wherein the layers are bonded
using ultrasonic energy.
7. The multi-layer article of claim 1 wherein said bond sites are
discrete thermal bonds having an aspect ratio of at least 3:1.
8. The multi-layer article of claim 1 wherein said first or second
layer comprises a non-woven material.
9. The multi-layer article of claim 1 wherein said third material
comprises a material selected from the group consisting of
cellulosic tissue paper, metal foil, treated materials, polymeric
film, open cell foams, pulp, other absorbent materials, polymeric
absorbent gelling materials, and combinations thereof.
10. The multi-layer article of claim 1 wherein said laminate is
extensible.
11. The multi-layer article of claim 10 wherein first ply comprises
an extensible web having a first elongation to break.
12. The multi-layer article of claim 10 wherein said second ply
comprises an extensible web joined to said first ply at a plurality
of bond sites, said second extensible web having a second
elongation to break.
13. The multi-layer article of claim 10 wherein said first ply is a
first extensible web having a first elongation to break and said
second ply is a second extensible web joined to said first
extensible web at a plurality of bond sites, said second extensible
web having a second elongation to break.
14. The multi-layer article of claim 13 wherein said first or
second extensible web comprises a non-woven material.
15. A multi-layer article comprising a first layer and a second
layer bonded to each other, said first layer comprising a laminate
web having a plurality of apertures, said laminate web comprising
first and second extensible webs being joined at a plurality of
discrete bond sites, a third material disposed between said first
and second extensible webs, and said first and second extensible
webs being in fluid communication via said apertures and having
distinct regions being differentiated by at least one property
selected from the group consisting of basis weight, fiber
orientation, thickness, and density.
16. The multi-layer article of claim 15 wherein said laminate web
is joined by bonds in the absence of adhesive.
17. The multi-layer article of claim 15 wherein said first layer
further comprises a cellulosic web.
18. The multi-layer article of claim 15 wherein said third material
comprises a material selected from the group consisting of
cellulosic tissue paper, metal foil, treated materials, polymeric
film, open cell foams, pulp, other absorbent materials, polymeric
absorbent gelling materials, and combinations thereof.
19. The multi-layer article of claim 15 wherein said bond sites are
discrete thermal bonds having an aspect ratio of at least 10:1.
20. The multi-layer article of claim 15 wherein said first or
second extensible web comprises a material selected from the group
consisting of cellulosic materials, non-woven materials, and
combinations thereof.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 10/192,372, filed on Jul. 10, 2002 which claims the benefit of
U.S. Provisional Application Ser. No. 60/308,749, filed Jul. 30,
2001; and this application is also a continuation of US Application
No. PCT/US00/34746, filed on Dec. 20, 2000 which claims priority to
U.S. application Ser. No. 10/149,878, filed Dec. 20, 2000 which is
a continuation-in-part of U.S. application Ser. No. 09/584,676,
filed on May 31, 2000 which is a continuation-in-part of U.S.
application Ser. No. 09/467,938, filed on Dec. 21, 1999, now issued
as U.S. Pat. No. 6,884,494 on Apr. 26, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates to a multi-layer article. More
particularly, an article with at least one layer that is an
absorbent cellulosic web, and at least one layer that is a
multi-ply laminate with at least three plies, including a center
ply that is apertured.
BACKGROUND OF THE INVENTION
[0003] Laminate articles formed by the joining of discrete webs in
a layered relationship are well known in the art. Laminate articles
include laminates of dissimilar materials. The materials may be
dissimilar in mechanical tensile properties, thermal properties, or
visual/tactile properties. For example, a non-woven web may be
joined to a relatively stiff fabric to provide for a soft surface
feel to the fabric.
[0004] The dissimilar materials may be joined by melt bonding,
adhesive bonding, ultrasonic bonding, and the like. Bonding methods
are often determined by the materials themselves, and often require
adhesive bonding. For example, a laminate of materials having
widely differing melt properties may require an adhesive layer
between laminate layers. Even materials having similar melt
properties, such as non-woven and thermoplastic film materials are
often joined by adhesive for adequate bonding to prevent unwanted
delamination. Although adhesive may be necessary, such processing
methods can be expensive due to the addition of adhesive, and the
resulting laminate is often relatively stiff, depending on the
laminate materials and the level of adhesive added.
[0005] Often laminate articles are intended to combine properties
of the constituent layers to achieve synergistic benefits. For
example, a multi-layered non-woven laminated article could be
intended for use as a substitute for a woven web such as a textile
web. A web comprised of a layer of thermoplastic man-made fibers
and a layer of cellulose-based fibers is known. The cellulose-based
fiber layer is disclosed as thermally bonded to the thermoplastic
man-made fiber layers at spaced apart locations. However, it
appears that thermal bonding between all the layers is necessary to
produce the requisite bonding.
[0006] EP-A-112,654 issued to Haq, et al. discloses a laminate
comprising two sheets of non-woven fabric or the like having
sandwiched between them a solid core material which may be a highly
porous, optionally liquid-containing, polymer. The two outer sheets
are bonded to each other, without involving the core material, by
means of a plurality of small, spaced bonding points, for example,
spot-welds. Preferably the core material is in continuous sheet
form and is perforated to accommodate the bonding points. However,
it appears it would present a significant processing problem to
register the perforations of the core material in order to have the
outer layers bonded therethrough.
[0007] Non-woven webs are beneficial as components of disposable
consumer products, such as diapers, incontinence briefs, training
pants, feminine hygiene garments, and the like, as well as in wipes
such as disposable wet wipes. However, used alone, such non-wovens
are limited in the range of beneficial properties, including
visual, tactile, strength or absorbent properties due to the limits
of known methods of making, particularly as compared to woven or
knitted materials. Importantly, laminates of non-woven webs and
other materials for use in disposable consumer products have
heretofore been limited due to processing limitations, including
incompatible materials (e.g., thermally dissimilar materials), cost
considerations (e.g., adhesive lamination costs) or tactile
properties (e.g., softness and visual aesthetics).
[0008] Also known in the art is a laminate of at least three layers
with the outermost layers bonded to each other through apertures
formed in the center or inner layer(s) during the bonding process.
Such laminates have a variety of possible properties depending upon
the choice of materials for the outer and inner layers. It is
possible to achieve a soft, cloth-like hand feel through the use of
non-woven outer layers, and to add absorbency by using a cellulosic
center layer similar to a BOUNTY.RTM. paper towel. The continuity
of the inner layer is disrupted however, because the layer is
apertured at the bond sites between the outer layers.
[0009] Accordingly, it would be desirable to have laminate articles
with webs of dissimilar material properties, which are not
dependent upon thermal compatibility of each constituent layer for
structural integrity.
[0010] Additionally, it would desirable to have a laminate article
comprising both non-woven webs and cellulosic webs.
[0011] Additionally, it would be desirable to have a laminate web
formed by joining the constituent layers without adhesive.
[0012] Further, it would be desirable to have a multi-layer web
combining the softness and durability of a non-woven layer with the
absorbency of a continuous cellulosic layer.
SUMMARY OF THE INVENTION
[0013] The present invention provides a multi-layer article
comprising a first layer and a second layer bonded to each other.
The first layer comprises a first ply and a second ply joined to
the first ply in face-to-face relationship at a plurality of
discrete bond sites. The first and second plies form an interior
region therebetween. A third material is disposed between the first
and second plies. The third material is differentiated from the
first or second ply by at least one material property selected from
the group consisting of thermal properties, elongation properties,
elastic properties, conductive properties, and combinations
thereof. The third material substantially fills the interior
region. Additionally, the third material is apertured in regions
coincident with the bond sites such that the first and second plies
are joined through the apertures.
[0014] The present invention also provides for a multi-layer
article comprising a first layer and a second layer bonded to each
other. The first layer comprises a laminate web having a plurality
of apertures. The laminate web comprises first and second
extensible webs being joined at a plurality of discrete bond sites.
A third material is disposed between the first and second
extensible webs. The first and second extensible webs are in fluid
communication via the apertures and have distinct regions being
differentiated by at least one property selected from the group
consisting of basis weight, fiber orientation, thickness, and
density.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective of one embodiment of the first layer
of the present invention;
[0016] FIG. 2 is a cross sectional view taken along line 2-2 of
FIG. 1;
[0017] FIG. 3 is a magnified detail view of an exemplary bond site
of the first layer;
[0018] FIG. 4A is a magnified plan view of an exemplary bond
site;
[0019] FIG. 4B is a plan view of a portion of an exemplary bond
site pattern;
[0020] FIG. 5 is a schematic representation of a process for making
a laminate article of the present invention;
[0021] FIG. 6 is a perspective view of an exemplary melt bond
calendaring apparatus;
[0022] FIG. 7 is a cross sectional view of an exemplary multi-layer
article;
[0023] FIG. 8 is a top plan view of an exemplary embodiment of the
first layer; and,
[0024] FIG. 9 is a cross-sectional view taken along line 9-9 of
FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
[0025] As used herein, the term "absorbent article" refers to
devices that absorb and contain body exudates, and, more
specifically, refers to devices that are placed against or in
proximity to the body of the wearer to absorb and contain the
various exudates discharged from the body. The term "disposable" is
used herein to describe absorbent articles not intended to be
laundered, or otherwise restored or reused (i.e., they are intended
to be discarded after a single use and, preferably, to be recycled,
composted or otherwise disposed of in an environmentally compatible
manner). A "unitary" absorbent article refers to absorbent articles
that are formed of separate parts united together to form a
coordinated entity so that they do not require separate
manipulative parts like a separate holder and liner.
[0026] As used herein, the term "non-woven web" is used in its
plain meaning as understood in the art and refers to a web that has
a structure of individual fibers or threads which are interlaid,
but not in any regular, repeating manner. Non-woven webs have been,
in the past, formed by a variety of processes, such as, for
example, melt-blowing processes, spin-bonding processes, and bonded
carded web processes.
[0027] As used herein, "laminate" and "composite" when used to
describe webs of the present invention, are synonymous. Both refer
to a web structure comprising at least two webs joined in a
face-to-face relationship to form a multiple-layer unitary web.
[0028] As used herein, the term "extensible" refers to any material
that, upon application of a biasing force, is elongatable, at least
about 25 percent without experiencing catastrophic failure.
Catastrophic failure includes substantial tearing, fracturing,
rupturing, or other failure in tension such that, if tested in a
standard tensile tester, the failure would result in a sudden
significant reduction in tensile force. As used herein, the term
"highly extensible" refers to any material that, upon application
of a biasing force, is elongatable, at least about 100 percent
without experiencing catastrophic failure.
[0029] A multi-layer article of the present invention comprises at
least a first layer and a second layer. The layers are bonded at
one, or a plurality of, bond sites to each other in a face-to-face
relationship. The bond site(s) comprises a macroscopic pattern on
the face of the article. The pattern may include bonding along the
edge of the article as well as disposed across the interior face of
the article. The edge of the article is considered to be the area
of the article from the perimeter of the article, extending inward
about one inch (25 mm). The remainder of the area of the article is
considered to be the interior face of the article. The bonding
along the edge prevents delamination of the article at the edge.
Delamination, or the separation of the layers of the article,
reduces the unitary feel of the article and is therefore
undesirable.
[0030] The layers may be continuously bonded to each other. An
example of continuous bonding is an article with bonding at the
edge that extends uninterrupted along the entire perimeter of the
article.
[0031] The layers may also be bonded with a pattern comprised of a
plurality of discrete bonding sites. The shape of the bond sites is
not critical to the invention. Square, oval, circular, triangular,
line segments, and arc segments have all been found acceptable. The
bond sites of the article must be larger in area than the bond
sites of the first layer. It is believed that article bond sites
that are smaller than the bond sites of the first layer and are
coincident with bond sites of the first layer will produce an
aperture through the first layer. In this instance, no bonding
between the first and second layers occurs.
[0032] The bonding area of the article, as used herein, is defined
as the sum of the areas of all the bond sites between the first and
second layers, divided by the overall area of the article. Bonding
area is expressed as a percentage. For example, an article with an
area of 10 square inches, where the sum of the areas of all the
bonding sites between the layers is one square inch has a bonding
area of 10%. The bond sites between the first and second plies of
the first layer are not included in this calculation.
[0033] Higher bonding areas result in a more unitary article.
Higher bonding areas also reduce the overall absorbent capacity of
the article by reducing the caliper of a greater portion of the
article. Higher bonding areas can also result in a stiffer article
and in a reduction in the softness of the article. This is because
there is a reduction or alteration in the surface properties of the
first and second layers of the article in the regions of the bond
sites. The melting of the fibers of the first layer reduces the
softness of the article and the reduction in the caliper of the
second layer reduces the absorbent capacity of the article.
[0034] An article bonded only at the edge may have a bonding area
as low as 2%. Articles with bonding throughout the interior face as
well as the edge may have bonding areas as high as about 60%. One
embodiment of the article having a soft, absorbent, cloth-like
feel, has a bonding area of between 3% and 10%. The actual bonding
area in such an embodiment depends upon the size and number of
bonds along the edge.
[0035] The bond sites disposed throughout the interior of the
article provide structural unity for the article. These sites
provide the article with a greater unitary hand feel that is more
like a woven textile or cloth-like. The pattern of the interior
bond sites is not critical to the invention and any pattern of
sites producing the desired level of unitary feel without
compromising the absorbent capacity, or softness of the article,
may be used. Geometrically regular patterns or irregular patterns
may be used. Patterns in any shape comprised of a series of
discrete bond sites, also of any shape, may be used.
[0036] FIGS. 4A and 4B illustrate the bond sites shape and bond
site pattern of one embodiment of the present invention. In such an
embodiment, the dimensions 300 and 400 are about 0.3125 inches (8
mm). The bond sites in such an embodiment are arrayed in a pattern
across the interior face of the article similar to the pattern
shown in FIG. 4B. In such a pattern the bond sites are located on
centers spaced about 0.5 inches (12.5 mm) apart. The rows and
columns of sites in the pattern are spaced about two to three
inches (50 to 75 mm) apart. A similarly shaped, but larger, bond
site is utilized along the edge of the article in such an
embodiment. This larger bond site has dimensions 300 and 400 of
about 0.5 inches (12.5 mm) and the sites are arrayed on centers
spaced 0.625 inches (16 mm) apart.
[0037] The continuity of the layers is maintained with both
continuous and discrete bonding. Although the caliper of the second
layer is reduced in the bond sites the absorbent capabilities of
the layer are not eliminated. The layers are not pierced and
maintain their continuity. For the cellulosic second layer, this
continuity allows absorbed fluids to easily migrate throughout the
sheet. This ease of fluid migration is important to maintaining the
rate of absorption of the cellulosic web and the article.
[0038] The First Layer
[0039] In the non-limiting embodiment shown in FIG. 2, the first
layer 10 of the present invention preferably comprises at least
three plies disposed in a layered, face-to-face relationship. The
plies should be sufficiently thin to be processible as described
herein, but no actual thickness (i.e., caliper) is considered
limiting. First outer ply 20 is preferably thermally bondable, and
may be a non-woven web comprising a sufficient quantity of
thermoplastic material, the ply having a predetermined
extensibility and elongation to break. "Sufficient quantity" means
a quantity of thermoplastic material adequate to enable enough
thermal bonding upon application of heat and/or pressure to produce
a unitary layer. A second outer ply, 40, is preferably the same
material as first outer ply 20, but may be a different material,
also being thermally bondable and having a predetermined
extensibility and elongation to break.
[0040] In addition to thermoplastic non-woven materials, the outer
plies of the first layer 10 can comprise a polymeric film, for
example a polyolefinic (e.g., PP or PE) film. If the entire outer
plies are not uniformly thermoplastic, at least sufficient amounts
to effect melt bonding should be thermoplastic. Conjugate fibers,
such as bi-component fibers can be used in the outer layers to
facilitate thermal bonding of the outer layers. The outer plies of
the first layer can comprise a formed film, such as a
three-dimensional formed film having micro-apertures as described
in commonly assigned U.S. Pat. Nos. 4,629,643 and 4,609,518.
[0041] Any non-woven outer plies used in accordance with the
present invention may be extensible, highly extensible, elastic,
highly elastic and/or non-elastic. The non-woven plies may be any
melt-fusible web, including a spun-bonded ply, a melt-blown ply, or
a bonded carded ply. If the non-woven ply is a web of melt-blown
fibers, it may include melt-blown microfibers. The non-woven ply
may be made of fiber forming polymers such as, for example,
polyolefins. Exemplary polyolefins include one or more of
polypropylene, polyethylene, ethylene copolymers, propylene
copolymers, and butene copolymers. The non-woven plies may also
comprise synthetic cellulose fibers, or extruded starch fibers. The
non-woven plies can have a basis weight between about 10 to about
90 grams per square meter (gsm), or in another embodiment about 15
to about 30 gsm.
[0042] Further, any non-woven outer plies used in accordance with
the present invention may themselves be a multi-layer material
having, for example, at least one layer of a spun-bonded web joined
to at least one layer of a melt-blown web, a bonded carded web, or
other suitable material. For example, the non-woven ply may be a
multi-layer web having a first layer of spun-bonded polypropylene
having a basis weight from about 0.2 to about 8 ounces per square
yard, a ply of melt-blown polypropylene having a basis weight from
about 0.2 to about 4 ounces per square yard, and a second ply of
spun-bonded polypropylene having a basis weight from about 0.2 to
about 8 ounces per square yard. Alternatively, the non-woven plies
may be a single layer of material, such as, for example, a
spun-bonded ply having a basis weight from about 0.2 to about 10
ounces per square yard or a melt-blown ply having a basis weight
from about 0.2 to about 8 ounces per square yard.
[0043] Such non-woven outer plies may also be a composite
comprising a mixture of two or more different fibers or a mixture
of fibers and particles. Such mixtures may be formed by adding
fibers and/or particulates to the gas stream in which melt-blown
fibers or spunbond fibers are carried so that an intimate entangled
co-mingling of fibers and other materials, (e.g., wood pulp, staple
fibers, synthetic cellulose, starch fibers and particles) occurs
prior to collection of the fibers. Prior to processing, the
non-woven web outer ply of fibers can be joined by bonding to form
a coherent web structure. Suitable bonding techniques include, but
are not limited to, chemical bonding, thermobonding, such as point
calendering, hydro-entangling, and needling.
[0044] At least one third central ply 30 is disposed between the
two outer plies. The first layer 10 is processed by joining means,
such as by ultrasonic welding, or thermal calendaring to provide a
plurality of melt bond sites 50 that serve to couple the outer
plies 20 and 40, thereby forming the constituent plies into a
unitary layer. When joined together, the two outer plies form an
interior region therebetween. The interior region is the space
between the outer plies surrounding the bond sites 50. In one
embodiment, central ply 30 substantially fills the interior region,
central ply 30 being apertured coincident the bond sites 50.
[0045] While the first layer 10 is disclosed primarily in the
context of non-woven plies and composites, in principle the first
layer 10 can be made out of any materials that meet the
requirements, (e.g., melt properties, extensibility) as disclosed
herein. For example, the outer plies 20 and 40 can be thermoplastic
films, micro-porous films, apertured films, and the like. Central
ply 30 can be paper, including tissue paper, metal, including metal
foil; other non-thermoplastic web material, woven fabric, and the
like. In general, it is required that outer ply materials be
flexible enough to be processed as described herein.
[0046] One benefit of the laminate of the present invention is the
ability to provide a first layer 10 as a structure of dissimilar
materials without the use of adhesive for joining. Because the
central ply 30 of the first layer 10 can be formed by the
penetration of the protuberances of the calendaring roll at melt
bond sites, first layer 10 can comprise non-thermally-bondable
materials. The plurality of melt bond sites 50 are sufficient to
keep the component webs together in the laminate web, so that the
laminate web behaves as a unitary web for processing integrity and
use, without unwanted delamination. However, in some embodiments,
and for certain materials, it may be beneficial to apply adhesive
between at least two of the constituent layers.
[0047] The first layer 10 of the present invention, being bonded by
a plurality of relatively closely spaced thermal bond sites
(without the use of thermoplastic adhesives) can be beneficially
used for durable multi-layer articles. For example, a multi-layer
article of the present invention comprising non-woven web outer
layers and having a cloth-like feel and appearance can be used in
durable garments. Certain embodiments of the multi-layer article of
the present invention can survive repeated washing and drying in
household washing and drying equipment, depending on the component
webs of the laminate, and the level of thermal bonding. Due to the
knit-like or fabric-like look and feel of certain embodiments of
the present invention, such durability can result in durable
garment components such as inter-liners and the like.
[0048] Non-Apertured Embodiment
[0049] In one embodiment, as shown in cross-section in FIG. 2,
central ply 30 can be apertured, without aperturing the two outer
plies to provide a three-ply laminate characterized by the first
layer 10 (as a whole) being un-apertured, while central ply 30 is
apertured. Importantly, the first layer 10 can be made without
requiring registration of the plies and material to ensure bonding
of the outer plies through the apertures of central ply 30. One way
of describing the embodiment of a first layer 10 as described
above, is that the unitary layer 10, when viewed orthogonally by
the un-aided human eye from a distance of approximately 50 cm,
exhibits no apertures or perforations through the entire laminate,
but bond sites 50 are nevertheless visible.
[0050] The first layer 10 is further characterized in that the
joining of the three plies into a unitary web can be achieved in
the absence of adhesive. That is, in certain preferred embodiments
no adhesive is required to bond the plies together; joining is
achieved by the input of energy into the constituent layers, such
as by thermal melt bonding of the two outer layers together at the
melt bond sites 50. In other embodiments, the energy input can be
via ultrasonic bonding. Accordingly, a significant benefit of the
present invention is the provision of a laminate web, that is a
unitary web, formed without the use of adhesives. Not only does
this simplify processing and lower the cost of the laminate web,
when certain materials such as non-woven webs are used, it results
in a more flexible, softer web.
[0051] As shown in FIG. 2, central ply 30 is chosen such that when
the constituent plies of first layer 10 are processed, portions of
central ply 30 in the region of the melt bond sites 50 separate to
permit the first outer ply 20 to melt bond directly to the second
outer ply 40 at the interface of the two materials 52 at melt bond
sites 50. Thus, apertures in central ply 30 are formed in the
lamination step by displacement, just prior to the bonding of the
outer plies. In this manner, central ply 30 can be provided as an
unapertured ply, avoiding complex registration steps to align
apertures in registry with bond sites when laminated. Further,
central ply 30 need not be thermally compatible with outer plies 20
and 40. Central ply need not be a thermoplastic material, and need
not even have a melting point. It simply needs to be displaceable
by the forces exerted by the processing equipment as detailed
below. Therefore, one way of describing the first layer 10 of the
present invention is to distinguish the central ply 30 as being a
material differentiated from the materials of the first or second
plies by at least one material property selected from thermal
properties, or elongation properties. By "thermal properties" is
meant primarily thermal melt properties, such that the central ply
has no melting point, or if it has a melting point, it is
preferably at least about 10 degrees Centigrade higher, more
preferably about 20 degrees Centigrade higher than either outer
ply, and can be 100 degrees Centigrade higher than either outer
ply. By "elongation properties" is meant that in tension, the
material of the central ply exhibits an elongation to break that is
at least 100% less than either outer ply, more preferably 50% less
than either outer ply, and can be greater than 100% less than
either outer ply. Thus, the central ply can be extensible, while
either outer ply can be highly extensible.
[0052] An advantage of such a laminated web is that, in some
embodiments, e.g., for solid core central ply 30 materials (i.e., a
continuous sheet, that is, not having substantial apertures, gaps,
or other voids), it results in a unitary web having an apertured
central ply 30 in full, intimate contact with the outer plies 20,
and 40. By "full" and "intimate" is meant that central ply 30 fills
all the unbonded regions between outer plies 20 and 40 such that
outer plies 20 and 40 do not contact except at the bond sites 50.
Of course, it is recognized that many materials of interest have
significant air content, and filling "all" the unbonded region
between outer plies 20 and 40 is not meant to imply that all air
content is removed.
[0053] Central ply 30 can be involved, or participate, in the
bonding between outer plies 20 and 40. By "involved" is meant that
the central ply can, to some extent, be in intimate contact with,
and possibly partially merged with, one or both immediate outer
plies. The involvement may be due to actual melt bonding about the
perimeter of bond site 50 (e.g., for thermoplastic central plies
30), or it may be due to mechanical interaction, such as by
entanglement (e.g., for cellulosic fibrous central ply 30 between
fibrous non-woven plies), also about the perimeter of bond site
50.
[0054] Such separation of central ply 30 can occur by shearing,
cutting, or otherwise fracturing the central ply 30, and displacing
the material of the central ply 30 sufficiently to permit thermal
bonding of the two outer plies 20 and 40. Thus, central ply 30 must
be chosen to have properties that permit such displacement.
Therefore, central ply 30 should have one or more of the properties
of relatively low extensibility, relatively high frangibility, or
relatively high deformability, such that the material of central
ply 30 can be "squeezed" or otherwise displaced out of the region
of thermal bond sites 50. Importantly, it is not required that the
central ply 30 be melted out of the region of the thermal bond
sites. Thus, central ply can be elastic, highly elastic,
extensible, or highly extensible, depending on the desired end
results and purposes of the resulting unitary web.
[0055] Without being bound by theory, it is believed that to
accomplish the displacement of central ply 30 to form apertures
therein and to bond the outer plies, the thermal point calendaring
described below should form thermal bond sites having a narrow
width W dimension and a high aspect ratio. For example, FIG. 3
shows the melt area of a single melt bond site 50 having a narrow
width dimension W and a high aspect ratio, i.e., the length, L, is
much greater than the width, W. The length L should be selected to
permit adequate bond area while width W is sufficiently narrow such
that the protuberance used to form the bond site (as described
below) can cut, shear, displace, or otherwise pierce the central
ply 30 at the region of the bond sites by the method described
below. Width W can be between about 0.003 inches and 0.020 inches,
but in a preferred embodiment, is between about 0.005 inches and
0.010 inches, and may be adjusted depending on the properties of
central ply 30.
[0056] It is believed that the aspect ratio of melt bond site 50
can be as low as about 3 (i.e., ratio of L/W equals 3/1). It can
also be between about 4 and 20. In one preferred embodiment, the
aspect ratio was about 10. It is believed that the aspect ratio of
the melt bond sites 50 is limited only by the corresponding aspect
ratio of the point bonding protuberances of the calendaring
roller(s), as detailed below.
[0057] In one embodiment, the longitudinal axis of each bond site,
1, which corresponds directionally to the length dimension of bond
site 50, is disposed in a regular, repeating pattern oriented
generally parallel to the machine direction, MD as shown in FIG. 1.
But the longitudinal axis of each bond site may be disposed in a
regular, repeating pattern oriented in the cross machine direction,
or randomly oriented in a mixture of cross and machine directions.
For example, the bond sites 50 can be disposed in a "herringbone"
pattern.
[0058] When non-woven webs are used as constituent plies of first
layer 10, an important distinction should be drawn between bond
sites 50 which bond together outer plies 20 and 40, and thermal
bond sites that may be present in the constituent plies themselves.
For example, non-woven webs are typically consolidated by thermal
bonding in a regular pattern of discrete spaced apart fused bonding
areas, such as the pattern disclosed in U.S. Pat. No. 3,855,046,
and the patterns shown generally in FIG. 5 of U.S. Pat. No.
5,620,779. Other films, non-woven webs, and the like may have
thermal embossments for aesthetic reasons. The first layer 10 may
comprise many thermal bond sites, some of which are bond sites 50,
and others which are bond sites in the base non-woven, for
example.
[0059] The bond sites of the base non-woven do not typically have
an aspect ratio greater than about 1, so that these bonds do not
typically form apertures in the constituent ply during the
stretching step disclosed below. Also, the spacing of such bond
sites is typically a repeating pattern of bonded and unbonded area
that may or may not provide for machine direction (MD) columns of
bonded area next to columns of unbonded area. After forming bond
sites 50, however, there is not likely to be any significant MD
columns of unbonded areas; the overall bond pattern of any
constituent non-woven fabric is a combination of existing bonded
areas and bond sites 50. Together the two sets of bond sites result
in a complex pattern of bond sites that may or may not be described
as columnar, regular, or uniform.
[0060] The resulting web of the first layer 10, as shown in
cross-section in FIG. 2, is a first layer 10 that is itself
unapertured, but the central ply 30 is apertured coincident the
regions of the bond sites 50. As stated above, by "unapertured" is
meant that, on the whole, the first layer 10 is considered
unapertured. It is recognized that the un-apertured first layer 10
of the first layer 10 may have localized cut through, or tearing at
bond sites 50 due to materials and processing variability or post
lamination handling. Ideally, such cut through of the entire web is
minimized and eliminated. Likewise, it is recognized that in some
instances, there may not be complete displacement of the central
ply 30 at all locations of bond sites 50 such that some localized
portions of central ply 30 may not be apertured (and the outer
plies not bonded). Nevertheless, the description herein is made for
the first layer 10 as a whole and is not to be limited by
aberrations or anomalies due to potential material or processing
variables.
[0061] The central ply 30 need not be thermally compatible with the
outer plies. The central ply 30 need not even be melt processible.
It can be, for example, a cellulosic material, such as paper; a
metallic material, such as a metal foil; a woven or knit material,
such as cotton or rayon blends; or a thermoset material, such as a
polyester or aromatic polyamide film, or a web comprised of starch
fibers. The central ply 30 can be another non-woven having suitable
properties for processing into an apertured ply. If central ply 30
has a melting point, it is preferably at least about 10.degree. C.
higher, more preferably about 20.degree. C. higher than the outer
plies. However, central ply 30 need not have a melting point, and
may simply experience softening at the calendaring temperatures
required to bond the laminate structure.
[0062] Central ply 30 can be any of a great number of dissimilar
materials. For example, if outer plies 20 and 40 are non-woven webs
having a relatively high elongation to break, central ply 30 can be
paper, tissue paper, thermoplastic film, metal foil, closed or open
cell foam, or any other material that has a relatively low
elongation to break compared to the two outer layers. The outer
layer materials may themselves be dissimilar, with the only
constraint being that the central layer be relatively less
extensible in the direction of extension to form apertures.
[0063] Additionally, more than one central ply 30 can be used with
beneficial results. For example, a structure comprising a
cellulosic tissue central web and a polymeric film central web
between two non-woven webs can produce an absorptive wiping article
with one side being relatively more absorptive than the other. If
the film layer is a three-dimensional formed film, the film side
can provide added texture to the laminate that is beneficial in
many wiping applications. Macroscopically-expanded,
three-dimensional formed films suitable for use in the present
invention include those described in U.S. Pat. Nos. 3,929,135 and
4,342,314.
[0064] Central ply 30 can be elastomeric, an elastomeric
macroscopically-expanded, vacuum-formed, three-dimensional formed
film, a three-dimensional formed film having micro-apertures, a web
material having a strainable network, absorbent gelling materials,
and the like.
[0065] Apertured Embodiments
[0066] A further benefit is obtained when the non-apertured
thermally bonded laminate first layer 10 described supra, is
stretched or extended in a direction generally orthogonal to the
longitudinal axis 1 of melt bond sites 50. The melt bonding at the
melt bond sites 50 tends to make localized weakened portions of the
layer at the bond sites. Thus, as portions of the first layer 10
are extended in a direction generally orthogonal to the
longitudinal axis 1 of bond sites 50, the material at the bond site
fails in tension and an aperture is formed. The relatively high
aspect ratio of melt bond sites 50, permits a relatively large
aperture to be formed upon sufficient extension. When the first
layer 10 is uniformly tensioned, the result is a regular pattern of
a plurality of apertures 45 corresponding to the pattern of melt
bond sites 50.
[0067] FIG. 8 shows a partially cut-away representation of an
apertured laminate of the first layer 10 of the present invention.
As shown, the partial cut-away permits each ply to be viewed in a
plan view. The first layer 10 shown in FIG. 8 is produced after the
thermally bonded laminate is stretched in a direction orthogonal to
the longitudinal axis of the melt bond sites, in this case, in the
cross-machine direction, CD with sufficient elongation in the
direction of extension to cause apertures to form. As shown, where
formerly were melt bond sites 50, apertures 45 are produced as the
relatively weak bond sites fail in tension. Also as shown, central
ply 30 can remain generally uniformly distributed within first
layer 10, depending on the material properties of central ply 30.
For example, if central ply 30 is more extensible than outer plies
20 or 40, then it simply extends, either elastically or by plastic
deformation, but remains generally uniformly distributed in the
unapertured regions of first layer 10. For example, if a
thermoplastic film is utilized as the central ply 30, it extends,
either extensibly or elastically (depending on the type of film),
but can remain generally uniform, for example, in density or basis
weight.
[0068] When apertures 45 are formed, the thermally bonded portions
of outer plies 20 and 40 remain primarily on the portions of the
aperture perimeters corresponding to the length dimension of bond
sites 50. Therefore, each aperture 45 does not have a perimeter of
thermally bonded material, but only portions remain bonded,
represented as 62 in FIG. 8. One beneficial property of such a
laminate web is that once apertured, fluid communication with the
central layer is facilitated. Thus, an absorbent central ply 30 can
be used between two relatively non-absorbent outer layers.
[0069] To the extent that central ply 30 is involved, or
participates, in any bonding between outer plies 20 and 40, it also
participates in the remnant of bonded portions 62, as shown in FIG.
4. The involvement may be due to some degree of actual melt bonding
about the perimeter of bond site 50 (e.g., for thermoplastic
central plies 30), or it may be due to mechanical interaction, such
as by entanglement (e.g., for a cellulosic fibrous central ply 30
between fibrous non-woven layers).
[0070] The first layer 10 may also be extended as described with
reference to FIG. 8, but with the central ply 30 chosen to have an
elongation to break, less than either of the two outer layers, and
less than the actual magnitude of extension. Thus, upon extension
of the laminate web generally orthogonal to the longitudinal axis 1
sufficient to form apertures in outer plies 20 and 40 (and thus the
entire first layer 10) central ply 30 fails in tension. Therefore,
central ply 30 fractures (i.e., fails in tension) upon sufficient
extension, so that after extension, central ply 30 is no longer
uniformly distributed over the non-apertured regions of the first
layer 10.
[0071] One example of a first layer 10 having a structure similar
to that shown in FIG. 5 is a web having outer layers of relatively
extensible non-wovens, with a central layer of relatively low
extensibility tissue paper. One particularly interesting structure
incorporates a highly hydrophobic outer layer combined with a
highly absorbent central layer. A suitable hydrophobic material is
described in U.S. Pat. No. 3,354,022. Such a material has a water
repellent surface having an intrinsic advancing water contact angle
of more than 90 degrees and an intrinsic receding water contact
angle of at least 75 degrees. When such a material is combined with
an absorbent central layer, such as a BOUNTY.RTM. paper towel
tissue layer, the resulting composite can be absorbent while
retaining a very clean and dry outer surface. The basis weight and
porosity of the outer layer can be varied to achieve different
degrees of absorbent performance.
[0072] One surprising beneficial characteristic of the laminate web
structure of the present invention is the presence of distinct
regions in the non-apertured portion of the web being
differentiated by at least one property selected from the group
consisting of basis weight, thickness, or density. In a preferred
embodiment, the regions are visually distinct, giving the laminate
an aesthetically pleasing look and feel. The regions may also give
the laminate a garment-like or knit-like texture.
[0073] In general, for a first layer 10 having generally parallel
rows of melt bond sites 50 extending in the machine direction MD,
which correspondingly form generally parallel rows of apertures
when extended, and having a central layer with a lower elongation
to break than the outer layers, the resulting extended, apertured
layer 10 is characterized by generally low basis weight, low
density regions between the apertures in the machine direction, MD.
Likewise, such a first layer 10 is characterized by relatively high
basis weight, high density regions between adjacent rows of
apertures in the cross-machine direction, CD. By choice of central
ply 30 material and possibly post laminating operations, e.g., an
embossing process, the thickness of the laminate web can likewise
be varied, the thicker regions generally corresponding to the
higher density regions.
[0074] The Second Layer
[0075] Referring to FIG. 7, the second layer 60 is preferably
bonded to first layer 10 by any means known to those of skill in
the art to form the multi-layered article. The second layer 60
preferably comprises an absorbent cellulosic fibrous web. A
cellulosic fibrous web is a fibrous, macroscopically
two-dimensional and planar, although not necessarily flat. However,
one of skill in the art would be able to use virtually any type of
material or combination of materials as second layer 60. Such
materials can include polymeric films, woven materials,
non-woven-materials, metallic films, apertured films, non-apertured
films, laminates, co-extruded films, composite webs of such
materials, and the like. Such a web does have some thickness in the
third dimension. However, this thickness is preferably very small
compared to the actual first two dimensions. Within the fibrous
structure may be at least two regions distinguished by an intensive
property such as basis weight, density, projected average pore size
or thickness. Such a web is disclosed in U.S. Pat. No. 5,277,761.
However, one of skill in the art will readily appreciate that
second layer 60 can comprise any material suitable for an intended
use of the multi-layer article. Exemplary, but non-limiting,
materials can be absorbent, non-absorbent, cellulosic tissue paper,
metal foil, treated materials, polymeric film, open cell foams,
pulp, other absorbent materials, polymeric absorbent gelling
materials, and combinations thereof. Additionally, second layer 60
can comprise a portion of a complete multi-layered article, such as
a wipe, diaper, or the like.
[0076] Two-dimensional cellulosic webs suitable for use as the
second layer 60 are preferably composed of fibers, which are
approximated by linear elements. The fibers are components of the
two-dimensional fibrous web, which components have one very large
dimension (along the longitudinal axis of the fiber) compared to
the other two relatively very small dimensions (mutually
perpendicular, and both radial and perpendicular to the
longitudinal axis of the fiber), so that linearity is approximated.
While, microscopic examination of the fibers may reveal two other
dimensions, which are small, compared to the principal dimension of
the fibers, such other two small dimensions need not be
substantially equivalent or constant throughout the axial length of
the fiber. It is only important that the fiber be able to bend
about its axis and be able to bond to other fibers.
[0077] The fibers may be synthetic, such as polyolefin or
polyester; may be cellulosic, such as cotton linters, rayon or
bagasse; or may be wood pulp, such as softwoods (gymnosperms or
coniferous) or hardwoods (angiosperms or deciduous) or layers of
the foregoing. As used herein, a fibrous web is considered
"cellulosic" if the fibrous web comprises at least about 50 weight
percent or at least about 50 volume percent cellulosic fibers,
including but not limited to those fibers listed above. A
cellulosic mixture of wood pulp fibers comprising softwood fibers
having a length of about 2.0 to about 4.5 millimeters and a
diameter of about 25 to about 50 micrometers, and hardwood fibers
having a length of less than about 1 millimeter and a diameter of
about 12 to about 25 micrometers has been found to work well for
the fibrous webs described herein.
[0078] Such a fibrous web suitable for use as second layer 60 may
be comprised of a single ply or of multiple plies. Each of the
plies comprising the fibrous web may be embossed or nonembossed. An
exemplary ply can comprise a tissue paper such as a BOUNTY.RTM.
paper towel, available from The Procter & Gamble Co.,
Cincinnati Ohio, USA. One of the beneficial characteristics in such
an embodiment is that the BOUNTY.RTM. sheet retains much of its
absorbency. The continuous web of the BOUNTY.RTM. is not disrupted
by the discontinuous bonding pattern. Therefore the BOUNTY.RTM.
sheet retains much of its absorbent capacity.
[0079] In one embodiment of the present invention, the center ply
30 disposed between the first and second plies 20,40 of the first
layer 10 is also a cellulosic web. Preferably, the cellulosic web
of the center ply 30 has a basis weight ranging from about 20 gsm
to about 50 gsm, and comprises a mixture of softwood pulp fiber and
hardwood pulp fiber, preferably with the softwood comprising from
about 50 to about 90 per cent of the web, and the hardwood
comprises from about 10 to 50 percent of the web.
[0080] The cellulosic webs of the present invention could be
produced by a through air drying process, by a conductive Yankee
drying process, or any other paper manufacturing process known in
the art. In one embodiment, a single ply of cellulosic web used as
the third material of the first layer, and bonded to a sheet of
BOUNTY.RTM. paper towel as the second layer. A representative
BOUNTY.RTM. paper towel is made by a through air dried process and
has a basis weight of 42 gsm and comprises 70% softwood and 30%
hardwood fibers. The absorbent rate of such an embodiment is
equivalent to the absorbent rate of two sheets of BOUNTY.RTM.. The
absorbent capacity of this embodiment exceeds that of an equivalent
amount of cellulosic material alone. This is surprising because the
embodiment contains less absorbent cellulosic structure than two
sheets of BOUNTY.RTM. and the non-woven plies of the first layer 10
do no add absorbent capacity.
[0081] The first layer 10 can also be more durable than the second
layer 60 and therefore can function as a cleaning surface to enable
more mechanically intensive cleaning with the article than is
possible with a cellulosic wipe such as a paper towel. The use of
non-woven outer plies in the first layer 10 results in a soft outer
surface in the present invention.
[0082] In one embodiment, the cellulosic second layer also
comprises an outer layer of the invention. Such an embodiment
demonstrates a high rate of absorption due to the direct exposure
of the absorbent cellulosic web to fluids.
[0083] Three Layer Embodiment
[0084] A third layer, substantially similar, or identical, to the
first layer may also be added as an outer layer. In such an
embodiment, the second layer is disposed between the first and
third layers. In such an embodiment, the second layer is bonded to
each of the first and third layers without aperturing the second
layer.
[0085] Such an embodiment has the advantage of a soft clothlike
feel on both sides of the article. Additionally, when the third
material of the third layer is a cellulosic web the article gains
additional absorbent capacity.
[0086] Method of Making
[0087] The laminate article is further characterized in that the
joining of the two layers into a unitary web can be achieved in the
absence of adhesive. That is, in certain embodiments no adhesive is
required to bond the layers together; joining is achieved by the
input of energy into the constituent layers, such as by thermal
melt bonding of the two layers together at the melt bond sites. In
other embodiments, the energy input can be via ultrasonic bonding,
by infrared bonding, or by pressure bonding. Accordingly, a
significant benefit of the present invention is the provision of a
laminate article, that is a unitary article, formed without the use
of adhesives. Not only does this simplify processing and lower the
cost of the laminate article, it results in a more flexible, softer
article.
[0088] FIG. 5 schematically illustrates a process for making the
laminate article of the present invention. A first layer 120, is
unwound from a supply roll 104, and travels in a direction
indicated by the arrows associated therewith as the supply roll 104
rotates in the direction indicated by the arrows associated
therewith. Likewise a second layer 140, is unwound from supply roll
105. The two components (or more, if more than two layers are used)
pass through a nip 106 of the thermal point bond roller arrangement
108 formed by rollers 110 and 112.
[0089] Referring to FIGS. 5 and 6, the non-woven thermal bond
roller arrangement 108 comprises a patterned calendar roller 110
and a smooth anvil roller 112. Roller 112, may be a smooth right
circular steel cylinder, and may have a coating of, for example,
urethane. Roller 112 may alternatively be a matched pattern roller.
One or both of the patterned calendar roller 110 and the roller 112
may be heated and the temperature of either roller and the pressure
between the two rollers may be adjusted by well known means to
provide the desired temperature, if any, and pressure to melt bond
the two layers together at a plurality of bond sites.
[0090] The patterned calendar roller 110 is configured to have a
circular cylindrical surface 114, and a plurality of protuberances
or pattern elements 116 which extend outwardly from surface 114.
The protuberances 116 are disposed in a predetermined pattern with
each protuberance 116 being configured and disposed melt bond the
two outer layers together at a plurality of locations. One pattern
of protuberances is shown schematically in FIG. 4B.
[0091] As shown in FIG. 6, patterned calendar roller 110 can have a
repeating pattern of protuberances 116 which extend about the
entire circumference of surface 114. Alternatively, the
protuberances 116 may extend around a portion, or portions of the
circumference of surface 114.
[0092] The height of the protuberances should be selected according
to the thickness of the laminate being bonded. In general, the
height dimension should be greater than the maximum thickness of
the laminate web during the calendaring process, so that adequate
bonding occurs at the bond sites, and only at the bond sites.
[0093] After passing through nip 106, the two (or more) component
webs 120, and 140 have been formed into unitary first layer 10. At
this point in the process the outer layers are thermally bonded to
each other and unapertured, as shown in FIGS. 1 and 7.
EXAMPLES
[0094] A preferred diaper configuration for a diaper comprising
laminates of the present invention is described generally in U.S.
Pat. No. 3,860,003. Alternatively, preferred configurations for
disposable diapers are also disclosed in U.S. Pat. Nos. 4,808,178,
4,695,278, 4,816,025, and 5,151,092.
[0095] In addition to disposable diapers, various embodiments of
laminates of the present invention are useful for topsheets,
backsheets, and cores in other disposable absorbent articles, such
as catamenials, panty liners, pull-up diapers, adult incontinence
products, and the like.
[0096] Laminates of the present invention can also be useful as
wipes, including wet wipes, shop wipes, facial wipes, and the like.
For example, an absorbent cellulosic layer as central ply 30 would
be an excellent wipe for picking up spills and particulate matter
that can be captured in the apertures. Likewise, a polyethylene
film would be an excellent wipe for harsh jobs requiring a more
durable wipe having extra scrubbing capability. A laminate of the
present invention can be considered a durable or semi-durable rag
or sponge for most purposes.
[0097] Because of the virtually infinite variety of patterns
achievable by the method of the present invention, laminates of the
present invention can find use as components in home furnishings,
including drapes and upholstery. For example, very lacy, sheer
patterns can be made that are attractive as window coverings. The
colors can be varied easily by varying the component materials,
including central ply 30. Higher basis weight materials can be made
durable for seat coverings, particularly disposable seat coverings
useful in airplanes, buses, and the like.
[0098] Laminates of the present invention can be useful as
disposable bibs. For example, a polyethylene layer would serve as
an effective bib. Even apertured versions, depending on the size of
the apertures can be useful as bibs, as the apertures tend to
capture food particles better. After use as a bib the bib can be
used as a wipe to clean up the baby's surroundings after
eating.
[0099] A laminate web of the present invention can find use as a
filter for filtering fluids. Air, for example, can be filtered in
passing air through a suitably designed laminate web of the present
invention. For example, electrostatic air filters can be made by
laminating appropriate dissimilar polymeric non-woven materials. In
one embodiment the filter would comprise non-woven materials of
suitable material and pore size, and would be provided in an
unstretched condition, that is, in a laminate such as that shown
with respect to FIGS. 1 and 2. As the filter is used, and the pores
become blocked with filtered debris, the tension placed on the
filter media thereby would cause at least some of the bond sites 50
to open into apertures. Thus, the filter comprises a self-adjusting
media that prevents complete blockage of the filter, and avoids
overworking of blower motors and the like.
[0100] Other uses for laminates of the present invention include
medical dressings, textured wall coverings, mats and throws, mop
heads for dry or wet mops, and geo-textiles.
[0101] All documents cited in the Detailed Description of the
Invention are, in relevant part, incorporated herein by reference;
the citation of any document is not to be construed as an admission
that it is prior art with respect to the present invention. To the
extent that any meaning or definition of a term in this written
document conflicts with any meaning or definition of the term in a
document incorporated by reference, the meaning or definition
assigned to the term in this written document shall govern.
[0102] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
* * * * *