U.S. patent application number 16/846915 was filed with the patent office on 2020-07-30 for absorbent article having a composite web with visual signal thereon.
The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to Kasey Marie Gust, Christine Marie Luzader, David Christopher Oetjen.
Application Number | 20200237571 16/846915 |
Document ID | 20200237571 / US20200237571 |
Family ID | 1000004754091 |
Filed Date | 2020-07-30 |
Patent Application | download [pdf] |
![](/patent/app/20200237571/US20200237571A1-20200730-D00000.png)
![](/patent/app/20200237571/US20200237571A1-20200730-D00001.png)
![](/patent/app/20200237571/US20200237571A1-20200730-D00002.png)
![](/patent/app/20200237571/US20200237571A1-20200730-D00003.png)
![](/patent/app/20200237571/US20200237571A1-20200730-D00004.png)
United States Patent
Application |
20200237571 |
Kind Code |
A1 |
Gust; Kasey Marie ; et
al. |
July 30, 2020 |
Absorbent Article Having A Composite Web With Visual Signal
Thereon
Abstract
An absorbent article, having a topsheet, an absorbent core, an
an intermediate layer is described. The intermediate layer is
attached to an inner surface of the topsheet layer, and has a first
surface facing the inner surface of the topsheet, an opposing
second surface, and a thickness. An ink zone extends from the
second surface of the intermediate layer through the intermediate
layer and at least to the inner surface of the liquid-permeable
topsheet, wherein the ink zone comprises a plurality of discrete
ink deposits having a first portion and a second portion. The first
portion has a first colorant and the second portion has a second
colorant. The first colorant and the second colorant contrast in
color with the topsheet, and wherein at least some of the plurality
of discrete ink deposits is disposed on the inner surface of the
liquid-permeable topsheet layer.
Inventors: |
Gust; Kasey Marie;
(Cincinnati, OH) ; Oetjen; David Christopher;
(West Chester, OH) ; Luzader; Christine Marie;
(Loveland, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Family ID: |
1000004754091 |
Appl. No.: |
16/846915 |
Filed: |
April 13, 2020 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15331955 |
Oct 24, 2016 |
10646378 |
|
|
16846915 |
|
|
|
|
14057822 |
Oct 18, 2013 |
9492336 |
|
|
15331955 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 37/1284 20130101;
A61F 13/2077 20130101; A61F 13/84 20130101; A61F 13/51394 20130101;
B32B 38/145 20130101; A61F 13/15731 20130101; B32B 38/06 20130101;
A61F 13/15699 20130101; A61F 2013/51377 20130101; B32B 37/20
20130101; A61F 2013/8497 20130101; A61F 2013/15243 20130101; B32B
27/12 20130101; B32B 2555/02 20130101 |
International
Class: |
A61F 13/15 20060101
A61F013/15; A61F 13/20 20060101 A61F013/20; A61F 13/84 20060101
A61F013/84; B32B 38/00 20060101 B32B038/00; B32B 27/12 20060101
B32B027/12; A61F 13/513 20060101 A61F013/513 |
Claims
1. An absorbent article, comprising: a liquid-permeable topsheet
layer comprising an outer surface and an opposing inner surface; an
absorbent core; and an intermediate layer attached to the inner
surface of the liquid-permeable topsheet layer, comprising a first
surface facing the inner surface of the liquid-permeable topsheet
layer, an opposing second surface, and a thickness; wherein an ink
zone extends from the second surface of the intermediate layer
through the intermediate layer and at least to the inner surface of
the liquid-permeable topsheet, wherein the ink zone comprises a
plurality of discrete ink deposits, the plurality of discrete ink
deposits comprising a first portion of discrete ink deposits and a
second portion of discrete ink deposits, wherein the first portion
of discrete ink deposits comprises a first colorant and the second
portion of discrete ink deposits comprises a second colorant, and
wherein the first colorant and the second colorant contrast in
color with the topsheet, wherein at least some of the plurality of
discrete ink deposits is disposed on the inner surface of the
liquid-permeable topsheet layer.
2. The absorbent article of claim 1, wherein the plurality of
discrete ink deposits comprises a solvent-based ink.
3. The absorbent article of claim 1, wherein plurality of discrete
ink deposits comprises a black color.
4. The absorbent article of claim 1, wherein the first colorant and
the second colorant are different.
5. The absorbent article of claim 1, wherein the ink zone does not
extend to the outer surface of the liquid-permeable topsheet
layer.
6. The absorbent article of claim 1, wherein the intermediate layer
is a secondary topsheet and has a basis weight of from about 8 gsm
to about 55 gsm.
7. The absorbent article of claim 1, further comprising an adhesive
layer disposed between the first surface of the intermediate layer
and the inner surface of the liquid-permeable topsheet layer.
8. The absorbent article of claim 7, wherein the ink zone extends
through the adhesive layer.
9. The absorbent article of claim 1, wherein the intermediate layer
comprises a nonwoven web.
10. The absorbent article of claim 1, wherein the topsheet layer
has an air permeability of at least about 300 cubic ft. per minute
(cfm) per sq. ft.
11. The absorbent article of claim 6, wherein the intermediate
layer and the liquid-permeable topsheet layer have a total
thickness in the range of about 120 .mu.m to about 1.3 mm.
12. The absorbent article of claim 1, wherein the liquid-permeable
topsheet comprises a film and wherein the intermediate layer
comprises a nonwoven web.
13. The absorbent article of claim 1, wherein the liquid permeable
topsheet comprises a nonwoven web and wherein the intermediate
layer comprises a nonwoven web. J
14. The absorbent article of claim 1, wherein the first portion of
discrete ink deposits and the second portion of discrete ink
deposits produce a visual signal having an L* value of between 30
and 90.
15. The absorbent article of claim 1, wherein the first portion of
discrete ink deposits and the second portion of discrete ink
deposits produce a visual signal having an L* value of between 40
and 70.
16. The absorbent article of claim 1, wherein the first portion of
discrete ink deposits and the second portion of discrete ink
deposits are provided via digital printing.
Description
FIELD
[0001] This disclosure relates to absorbent articles, and more
specifically to a disposable absorbent article having an image
visible on a top surface. This disclosure further relates to a
process of printing on a composite web.
BACKGROUND
[0002] Absorbent articles which collect various exudates discharged
from the body, such as diapers, training pants, sanitary napkins,
pantiliners, interlabial devices, incontinence pads, incontinence
devices, tampons, and the like, are known in the art. These
absorbent articles often include one or more colored regions,
graphics, designs, and the like, sometimes referred to as visual
signals. Sanitary napkins and incontinence pads, for example,
sometimes include a visual signal which is proximal the central
portion of the absorbent article and which differs in color from
portions of the absorbent article remote from the central portion
of the absorbent article. Such visual signal can be produced by
printing (e.g., with ink) on or below the top surface of the
absorbent article. Some absorbent articles have a visual signal
that is printed on one layer underlying the topsheet and visible
through the topsheet. By printing on a layer below the topsheet,
such as a nonwoven web, the visual signal can be viewed through the
topsheet to provide for a perception of depth within the absorbent
article. Creating a perception of depth within the absorbent
article can reassure a user, prior to use, that during use fluid
will be drawn deep inside the product and away from a user's
body.
[0003] These absorbent articles often comprise at least one
low-basis-weight nonwoven web. There is a need to print visual
signals on these webs. However, as the basis weight of nonwoven
webs upon which ink is applied decreases, the likelihood of ink
blow-through during the printing process increases. Ink
blow-through can be undesirable, as it can detrimentally impact
manufacturing-line hygiene as well as increase manufacturing costs
due to wasted ink. Additionally, the perceived quality of a visual
signal produced from an image printed onto a nonwoven web may also
deteriorate as the basis weight of the nonwoven web is lowered.
Therefore, it is desirable to add mass to these low basis weight
webs prior to printing to reduce the likelihood of ink blow-through
during the printing process. With these limitations in mind, there
is a continuing unaddressed need for printing a quality visual
signal on a relatively low-basis-weight nonwoven web. Further,
there is a continuing unaddressed need for printing a visual signal
on a relatively low-basis-weight web of material while maintaining
a desired level of manufacturing line hygiene and cost
effectiveness. These are all goals of the present invention;
embodiments described herein may achieve various combinations of
these goals. A particular embodiment may, but need not, embody
every goal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The above-mentioned and other features and advantages of the
present disclosure, and the manner of attaining them, will become
more apparent and the disclosure itself will be better understood
by reference to the following description of non-limiting
embodiments of the disclosure taken in conjunction with the
accompanying drawings, wherein:
[0005] FIG. 1 is a top view of an absorbent article with some
layers partially removed in accordance with a non-limiting
embodiment of the present disclosure;
[0006] FIG. 2 is a cross-sectional view of the absorbent article
taken about line 2-2 of FIG. 1 in accordance with a non-limiting
embodiment of the present disclosure;
[0007] FIG. 3 is an exploded cross-sectional view of the absorbent
article of FIG. 2.
[0008] FIG. 4 is a cross-sectional view of a composite web
subsequent to receiving ink deposits during a printing process,
with the composite web comprising a secondary topsheet and a
liquid-permeable topsheet.
[0009] FIG. 5 is a cross-sectional view of a composite web
subsequent to receiving ink deposits during a printing process,
with the composite web comprising a secondary topsheet, an adhesive
layer, and a liquid-permeable topsheet.
[0010] FIG. 6 is a schematic side view of a process for producing a
composite web and then printing onto the composite web in
accordance with one non-limiting embodiment.
[0011] FIG. 7 is a schematic side view of a process for producing a
composite web and then printing onto the composite web in
accordance with one non-limiting embodiment.
DETAILED DESCRIPTION
[0012] Various non-limiting embodiments of the present disclosure
will now be described to provide an overall understanding of the
principles of printing a visual signal on a composite web. One or
more examples of these non-limiting embodiments are illustrated in
the accompanying drawings. Those of ordinary skill in the art will
understand that the printable composite webs described herein and
illustrated in the accompanying drawings are non-limiting
embodiments and that the scope of the various non-limiting
embodiments of the present disclosure are defined solely by the
claims. The features illustrated or described in connection with
one non-limiting embodiment may be combined with the features of
other non-limiting embodiments. Such modifications and variations
are intended to be included within the scope of the present
disclosure.
[0013] A process has been discovered for first combining two webs
into a composite web, and then printing on the second surface of
one web such that a resultant visual signal is visible from the
first surface of the other web. Thus, a printable composite web,
and method and apparatus for printing on a composite web are
disclosed. The composite web can comprise various types of material
layers, including one or more nonwoven layers. A nonwoven layer can
be combined with another nonwoven web, a formed film (e.g., an
apertured film), or combinations thereof, to form the composite
web. The composite web can be incorporated into an absorbent
article, with one layer of the composite web functioning as a
topsheet, for example, and another layer of the composite web
functioning as a secondary topsheet, or other component of the
absorbent article. Or, both layers of the composite web may
function as a composite topsheet, which in turn may be combined
with a separate secondary topsheet. While a variety of materials
can be incorporated into the composite web, in certain embodiments,
the nonwoven layer can have a basis weight ranging from about 8
grams per square meter (gsm) to about 55 gsm.
[0014] Air permeability (or porosity) is used herein as a way to
measure how easy it is for ink to pass through a material. A high
air permeability number generally means air (and thus ink) can
easily penetrate through the material. Low-basis-weight materials
typically have high air permeability as there isn't a lot of
material to block the air. As air permeability increases, so does
the potential for ink blow-through. Accordingly, to achieve a good
quality printed image with limited blow-through, it is desirable to
print onto a material having low air permeability combined with a
closed (vs open) molecular structure. It is advantageous to print
to a composite web versus printing simply to one layer, as
combining two layers of material helps create a closed structure
with low air permeability. For embodiments incorporating a formed
film in the composite web, the formed film, can be, for example, a
macroscopically-expanded, three-dimensional, fluid-pervious,
polymeric web. In certain embodiments, the formed film can have an
air permeability of at least about 200 cubic ft. per minute (cfm)
per sq. ft, or at least about 300 cfm per sq. ft., or at least
about 400 cfm per sq. ft., or at least about 500 cfm per sq. ft, or
or at least about 600 cfm per sq. ft. For embodiments incorporating
a higher basis-weight nonwoven in the composite web, the air
permeability of the composite web may be lower than 300 cfm per sq.
ft.
INTRODUCTION
[0015] "Absorbent article", as used herein, refers to disposable
devices such as infant, child, or adult diapers, pant-style
diapers, training pants, sanitary napkins, pantiliners,
incontinence pads, diaper inserts, and the like which are placed
against or in proximity to the body of the wearer to absorb and
contain the various exudates discharged from the body. Typically,
these articles comprise a topsheet, backsheet, an absorbent core,
and optionally other components, with the absorbent core normally
placed at least partially between the backsheet and the topsheet.
The absorbent articles of the present disclosure will be further
illustrated in the below description and in the Figures in the form
of a sanitary napkin. Nothing in this description should be,
however, considered limiting the scope of the claims. As such, the
present disclosure applies to any suitable form of absorbent
articles (e.g., training pants, adult incontinence products,
diapers, and so forth).
[0016] "Absorbent core", as used herein, refers to a structure
typically disposed between a topsheet and backsheet of an absorbent
article for absorbing and containing liquid received by the
absorbent article. The absorbent core can comprise one or more
substrate layers, an absorbent material disposed on the one or more
substrate layers, and a thermoplastic adhesive composition on the
absorbent material. The thermoplastic adhesive composition can be
on the absorbent material and at least a portion of the one or more
substrate layers. The absorbent core does not include an
acquisition system, a topsheet, or a backsheet of the absorbent
article. In a certain embodiment, the absorbent core would consist
essentially of the one or more substrate layers, the absorbent
material, the thermoplastic adhesive composition, and optionally a
cover layer.
[0017] "Nonwoven web", as used herein, means a manufactured sheet,
web, or batt of directionally or randomly orientated fibers, bonded
by friction, and/or cohesion, and/or adhesion, excluding paper and
products which are woven, knitted, stitch-bonded incorporating
binding yarns or filaments, or felted by wet-milling, whether or
not additionally needled. The fibers can be of natural or man-made
origin and can be staple or continuous filaments or be formed in
situ. Commercially available fibers can have diameters ranging from
less than about 0.001 mm to more than about 0.2 mm and can come in
several different forms such as short fibers (known as staple, or
chopped), continuous single fibers (filaments or monofilaments),
untwisted bundles of continuous filaments (tow), and twisted
bundles of continuous filaments (yarn). Nonwoven webs can be formed
by many processes such as meltblowing, spunbonding, solvent
spinning, electrospinning, carding, and airlaying. The basis weight
of nonwoven webs is usually expressed in grams per square meter
(g/m2 or gsm).
[0018] "Joined" or "bonded" or "attached", as used herein,
encompasses configurations whereby an element is directly secured
to another element by affixing the element directly to the other
element, and configurations whereby an element is indirectly
secured to another element by affixing the element to intermediate
member(s) which in turn are affixed to the other element.
General Description of an Absorbent Article
[0019] An example absorbent article 5 according to the present
disclosure, shown in the form of a sanitary napkin, is represented
in FIGS. 1-3. This type of absorbent article is shown for
illustration purpose only as the present disclosure can be used for
making a wide variety of other absorbent articles. FIG. 1 is a top
view of the example absorbent article 5, in a flat-out state, with
portions of the structure being cut-away to more clearly show the
construction of the absorbent article 5. FIG. 2 is a
cross-sectional view of the absorbent article of FIG. 1 taken along
line 2-2, while FIG. 3 is an exploded cross-sectional view of the
absorbent article of FIG. 2.
[0020] Referring to FIG. 1, the absorbent article 5 can have a
substantially planar configuration and a centroid 40. The centroid
40 is the in-plane center of mass of the absorbent article 5. The
centroid 40 is at the intersection between the longitudinal
centerline L and transverse centerline T. The transverse centerline
T is orthogonal to the longitudinal centerline L. The absorbent
article 5 can, but need not be, symmetric about the transverse
centerline T. The absorbent article 5 has a body-facing surface 10
and a garment facing surface (not shown).
[0021] Referring to FIGS. 1-3, the absorbent article 5 comprises a
plurality of layers to promote certain liquid handling behaviors.
Example layers include a liquid-permeable topsheet 30 and an
absorbent core 90. Some embodiments can also include a top core 22,
as illustrated. The absorbent core 90 can have a number of suitable
arrangements, for example the absorbent core 90 can have a tissue
outer wrapping 92 (FIG. 3). The absorbent articles can also have a
backing material 82 and a backsheet 80.
[0022] To help ensure that fluids flow into the absorbent core 90,
some absorbent articles are constructed with what is sometimes
referred to as a secondary topsheet 20 (STS) positioned
intermediate the topsheet 30 and the absorbent core 90. This
secondary topsheet 20 is designed to acquire the fluid on the
liquid-permeable topsheet 30 and distribute it to the underlying
absorbent core 90. To help ensure that the secondary topsheet 20
transfers the fluid to the absorbent core 90, the secondary
topsheet 20 can have sufficient capillarity to draw the fluid
through the liquid-permeable topsheet 30. To ensure that the fluid
flow continues onto the absorbent core 90, the secondary topsheet
20 can be designed with more permeability than the absorbent core
90, and less capillarity than the absorbent core 90. A secondary
topsheet can be an airlaid-tissue web made from hydrophilic
cellulosic fibers, sometimes referred to as an airlaid STS. Such
secondary topsheets, however, cannot typically be fusion bonded to
a liquid-permeable topsheet due to the use of plain cellulosic
fibers in the web. Accordingly, an adhesive can be used during the
manufacturing process as a bonding agent between the airlaid STS
and the liquid-permeable topsheet. If fusion bonding is desired, a
polyethylene (PE) powder can be incorporated into the airlaid
STS.
[0023] As shown in FIG. 3, each of the layers of the absorbent
article 5 have a first surface (shown as 30A, 20A, 22A, 90A, 82A
and 80A) and an opposing second surface (shown as 30B, 20B, 22B,
90B, 82B and 80B). The first surfaces 30A, 20A, 22A, 90A, 82A and
80A, or at least portions thereof, are generally oriented to be
body-facing, or wearer-facing, and the second surfaces 30B, 20B,
22B, 90B, 82B and 80B, or at least portions thereof, are generally
oriented to be garment-facing when the absorbent article 5 is in a
flat-out state.
[0024] The absorbent article 5 can be considered to have a viewing
surface that is the body-facing surface 10 (FIG. 1). The
body-facing surface 10 can be the side of the absorbent article 5
that is in contact with the wearer's body when the absorbent
article 5 is worn, as might be the case for a sanitary napkin,
pantiliner, or adult incontinence product, or is inserted into the
wearer's body, as might be the case for a tampon. For a generally
cylindrical tampon, the longitudinal centerline L is considered to
be on the body-facing surface 10 of the tampon, aligned with the
central axis of the tampon and the centroid 40 can be the midpoint
of the longitudinal centerline L.
[0025] When creating an absorbent article, such as a sanitary
napkin, having a visual signal, it is desirable to add ink to a
surface other than the body-facing surface of the article (e.g.,
first surface 30A of the topsheet 30); doing so minimizes the
chance of wearer irritation from the ink, maintains the aesthetic
clarity of the visual signal, or the like. Some current absorbent
articles comprise a secondary topsheet which is printed on its
first (body-facing) surface and then combined with a second layer,
such as a topsheet. Other current absorbent articles comprise a
topsheet which has been printed (e.g., with a flexographic printer)
on its second (garment-facing) surface and then combined with a
second layer, such as a secondary topsheet. The second surface 20B
of the secondary topsheet 20 can have ink, paint or other type of
colorant printed thereon. In the illustrated embodiment, ink
deposits 50 are printed onto the second surface 20B. The ink
deposits 50 can be any colorant suitable for deposition onto a
nonwoven web, including water-based inks or dyes, solvent-based
inks or dyes, phase transition inks (e.g., wax-based inks which are
solid at room temperature and must be melted to print), UV-curable
inks or dyes, paint, pigment, or liquid colorants such as food
coloring. The ink deposits 50 can produce a color contrasting with
the color of the secondary topsheet 20 and the liquid-permeable
topsheet 30 and can be, for example, primary colors and common
colors such as red, green, blue, yellow, pink, purple, orange, or
black. If the secondary topsheet 20 and/or the liquid-permeable
topsheet 30 is dark a color, colorant can be light colors such as
light gray, silver, white, or beige. The ink deposits 50 may be the
same color as the liquid-permeable topsheet 30 or secondary
topsheet 20, but in a different hue such that there is a noticeable
contrast, such as a light blue topsheet and a vivid blue ink
deposit. While the present discussion is generally directed to inks
applied to an absorbent article to yield a deliberate visual
signal, the process herein may also be used to apply another
substance (either having color or being generally colorless), such
as an adhesive, non-contact perfume, etc. to an inner layer of an
absorbent article. Further, the ink or other substance deposited
need not form a visual signal to reap the benefits.
[0026] It is common in the industry to print on the first surface
of a secondary topsheet and then combine it with a second layer,
such as a liquid-permeable topsheet; this yields a composite web
with a visual signal likely viewable from the first surface of the
secondary topsheet. But, this process can have disadvantages, such
as a high level of ink blow-through from printing to open, highly
porous individual layers. A process has been discovered for first
combining two webs into a composite web, and then printing on the
second surface of one web such that the resultant visual signal is
visible from the first surface of the other web. Ink deposits 50 on
the second surface 20B of the secondary topsheet 20 can be applied
after the secondary topsheet 20 has been combined with a second
layer, such as the liquid-permeable topsheet 30. In some cases, the
secondary topsheet 20 in combination with a second layer is
referred to as a composite web 70 (FIGS. 4, 5, 6 and 7), as
described in more detail below.
[0027] Exemplary printing processes for applying the ink deposits
50 include digital printing (e.g., with inkjet or laser printers),
gravure printing and flexographic printing. Other printing
processes as are known in the art can be used, each with various
advantages and disadvantages. One advantage of printing via a
flexographic printing process is that the nip setting at the
printing stage can be adjusted and set such that only the second
surface 20B of the secondary topsheet 20 contacts the inked roll in
a highly controllable manner. However, there are many advantages of
digital printing over flexographic printing: flexibility, smaller
footprint, operability, more automated, color response is not
dependent on operator settings (e.g., not dependent on the nip
setting as with flexographic printing since the desired color
saturation is in the image file that is loaded into the digital
printer). Thus, the preferred method of applying the ink deposits
50 is digital printing.
[0028] Yet, digital printing such as continuous inkjet printing can
result in ink passing through the layers of a web due to the high
drop speed (more so than may be seen with piezo/drop-on-demand or
flexographic printing). So, ink blow-through is more of a problem
when printing digitally than it is with other common printing
methods. It has been found that digital printing on a composite
formed film and low basis weight nonwoven or composite
nonwoven/nonwoven web results in improved image quality over single
web printing because more ink stays on the composite web because of
higher combined basis weight than printing on single web. Digital
printing onto a composite web also decreases the amount of blow
through; more ink stays on the composite web because of higher
combined basis weight than printing on single web. Further, digital
printing onto a composite web enables high visual signal quality
with online printing, but with low-cost, low-basis weight
materials.
[0029] The ink deposits 50 deposited on the second surface 20B of
the secondary topsheet 20 produce a visual signal 60 (FIG. 1) that
is at least partially visible (can be visually perceived by the
observer) through the body-facing surface 10. The visual signal 60
is visible when the body-facing surface 10 is presented towards an
observer even though liquid-permeable topsheet 30 is between the
observer and the secondary topsheet 20. It is possible to control
the ink penetration such that ink is deposited on more layers than
just the secondary topsheet. In some cases, the visual signal 60 is
produced not only by ink deposits 50 applied to the second surface
20B of the secondary topsheet 20 but also by ink deposits 50 that
reached (e.g., via capillary action) the second surface 30B of the
liquid-permeable topsheet 30 when the ink was applied to the
composite web 70 during the printing process. Accordingly, it is
possible to print on multiple layers during the same printing
step.
[0030] Referring to FIG. 1, when the body-facing surface 10 of the
absorbent article 5 is viewed, the absorbent article 5 can have a
background region 55. The background region 55 is a region that is
visually distinguishable from the visual signal 60. The background
region 55 can be white or any other color visually distinguishable
from the visual signal 60. Generally, the visual signal 60 can
render a perception of depth to the absorbent article 5 and in some
cases provide guidance for alignment. Further, one or more visual
signals 60 can communicate various functions of portions of
absorbent article 5, for instance, such portions of the absorbent
article 5 that might act or be perceived to act as a barrier to
flow of liquids. The visual signal 60 can be coincident with the
centroid 40, for instance when the centroid 40 is the in-plane
center of mass of the absorbent article 5, thereby showing the user
the location of the absorbent article 5 that should be proximal her
vaginal opening or urethra. Designs in which the visual signal 60
is symmetric about the longitudinal centerline can provide for a
more pleasing impression of the absorbent article 5. The visual
signal 60 may comprise one continuous shape, such as a peanut or
flower, or it may be comprised of multiple smaller shapes which,
taken together, form a graphic, design, or pattern.
[0031] Ink deposits 50 can be closely spaced so as to form a
substantially complete coverage of the second surface 20B of the
secondary topsheet 20, they can be spaced relatively far apart, or
they can be appropriately spaced to form a desired shape, pattern,
or graphic image, such as an oval or rectangle, for example. The
ink deposits 50 can be coincident with the longitudinal centerline
L, that is, a portion of the ink deposits 50 can intersect with the
longitudinal centerline L. Furthermore, the ink deposits 50 can
include a plurality of different colors to create the desired
visual signal 60 that is visible through the body facing surface
10. In one embodiment, ink deposits 50 are colorfast so that they
do not dissolve, degrade, or run when insulted with at least one of
water, urine, or menses. In another embodiment, ink deposits 50 can
be soluble in at least one of water, urine, or menses, such that
upon liquid insult the imprinted color changes or disappears. Such
color change can indicate wetness, volume of fluid, position of
fluid, and/or type of fluid. The shape, size, coloration,
placement, and intensity of the ink deposits 50 and resulting
visual signal 60 can be varied in ways limited only by the size of
the substrate and the printing techniques employed. For example, by
use of letter press, lithographic, screen printing, flexographic or
gravure printing techniques, virtually any graphic in any color or
color combination can be rendered on the second surface 20B of the
secondary topsheet 20. Moreover, by adjusting processing variables
such as the nip between rollers in a flexographic process, the
amount of ink and the position of ink can be varied to give various
impressions of color intensity, brightness/darkness, hue,
saturation, and depth perception.
[0032] FIG. 4 is a cross-sectional view of a composite web 70
subsequent to receiving ink deposits during a printing process. The
composite web 70 comprises the secondary topsheet 20 and the
liquid-permeable topsheet 30. The secondary topsheet 20 is a
nonwoven web having a plurality of fibers 21 and can have any
suitable basis weight. In some embodiments, for example, the
secondary topsheet 20 has a relatively low basis weight ranging
from about 8 grams per square meter (gsm) to about 70 gsm. In some
embodiments, for example, the secondary topsheet 20 has a basis
weight ranging from about 10 gsm to about 55 gsm. In some
embodiments, for example, the secondary topsheet 20 has a basis
weight ranging from about 15 gsm to about 40 gsm. In some
embodiments, for example, the secondary topsheet 20 has a basis
weight less than about 50 gsm. Additionally, pores of the secondary
topsheet 20 range in size from about 10 microns to about 200
microns. In some embodiments, the pores range in size from about 50
microns to about 100 microns. While the liquid-permeable topsheet
30 in FIG. 4 is illustrated as a formed film, the liquid-permeable
topsheet 30 can be any suitable type of material layer, such as a
nonwoven web, an apertured film, or a combination thereof. The
liquid-permeable topsheet 30 can have an air permeability of at
least about 300 cubic ft. per minute (cfm) per sq. ft. The
composite web 70 can have a total thickness, or caliper (per ASTM
D645), shown as T.sub.1, from about 120 .mu.m to about 1.3 mm;
T.sub.1 depends on the different layers combined to create the
composite web. In some embodiments, composite web 70 can be less
than about 120 .mu.m or more than about 1.3 mm.
[0033] The application of ink to the second surface 20B of the
secondary topsheet 20 during the printing process results in a
first volume, or portion, of ink 50A associated with the fibers 21
of the secondary topsheet 20 and a second volume, or portion, of
ink 50B that reaches the second surface 30B of the liquid-permeable
topsheet 30. Additionally, a third volume, or portion, of ink 50C
may pass through the liquid-permeable topsheet 30 during the
printing process. The third portion of ink 50C may be referred to
as ink blow-through. Despite the relatively low basis weight of the
secondary topsheet 20, the amount of ink blow-through 50C can still
be relatively low due to the joining of the secondary topsheet 20
with the liquid-permeable topsheet 30 prior to the application of
the ink. Providing another substrate (e.g., the top sheet) for the
ink to adhere to besides simply the secondary topsheet creates a
higher mass composite and thus a more tortuous path for the ink to
pass through. Accordingly, manufacturing line hygiene may not be as
detrimentally impacted as compared to other methods for printing
solely on low basis weight materials vs higher basis weight
composites. This also improves the clarity of the image printed as
compared to an image printed solely on low basis weight
materials.
[0034] In one embodiment, an intermediate layer is adhered to the
inner surface of the liquid-permeable topsheet layer to form a
composite web; the intermediate layer comprises a first surface
facing the inner surface of the liquid-permeable topsheet layer, an
opposing second surface, and a thickness. An ink zone extends from
the second surface of the intermediate layer through the
intermediate layer and at least to the inner surface of the
liquid-permeable topsheet. This yields a composite web with ink
present on more than one layer. In traditional printing processes,
wherein layers are first printed and then combined, the ink applied
to one or both layers is dry prior to the combination and doesn't
transfer to the other layer. So, the instant process is useful for
printing to multiple layers with one only printing step.
[0035] As shown in FIG. 5, the composite web 70 can include one or
more additional layers, such as an adhesive layer 120. In the
illustrated embodiment, the adhesive layer 120 bonds the first
surface 20A of the secondary topsheet 20 to the second surface 30B
of the liquid-permeable topsheet 30. The adhesive layer 120 can be
applied to either or both of the liquid-permeable topsheet 30 and
the secondary topsheet 20 during the manufacturing process. Since
the adhesive layer 120 is present when ink is deposited onto the
composite web 70, a volume of ink can be associated with the
adhesive layer 120, which is illustrated as a fourth volume, or
portion, of ink 50D.
[0036] The composite web 70 can have an ink zone 44 which extends
from the second surface 20B of the secondary topsheet 20, through
the secondary topsheet 20, and at least to the second surface 30B
of the liquid-permeable topsheet 30. For composite webs 70 having
an adhesive layer 120, as shown in FIG. 5, the ink zone 44 can
extend from the second surface 20B of the secondary topsheet 20,
through the secondary topsheet 20, through the adhesive layer 120,
and at least to the second surface 30B of the liquid-permeable
topsheet 30. Further, while FIGS. 4 and 5 illustrate at least a
portion of ink associated with each layer of the composite web 70,
this disclosure is not so limited. In fact, in some embodiments,
ink may only be associated with the secondary topsheet 20 and not
reach the liquid-permeable topsheet 30.
[0037] The volume of ink associated with the secondary topsheet 20
(shown as the first portion of ink 50A) may be about 30% to about
90% of the total volume of ink applied to the composite web 70 at
one time (e.g., at one printing unit with one or more print heads).
Additional volumes of ink may be applied to the the individual
layers making up the composite web prior to combination, to the
composite web alone, or to the composite web after combination with
additional layers in additional printing steps or units. The volume
of ink associated with the liquid-permeable topsheet 30 (shown as
the second portion of ink 50B) may be about 10% to about 70% of the
total volume of ink applied to the composite web 70 during the
printing process. In some embodiments, the volume of ink that is
blown through the composite web 70 during the printing process
(shown as the third portion of ink 50C) can be less than about 10%,
or less than about 5%, of the total volume of ink applied to the
composite web 70 during the printing process. This low level of ink
that is blown through the composite web with the current process is
advantageous in comparision to prior art means of printing on a low
basis weight secondary topsheet, for instance, due to line hygiene,
cost due to lost ink, and cost to clean wasted ink. For composite
webs 70 having an adhesive layer 120 (FIG. 5), the volume of ink
associated with the adhesive layer 120 (shown as the fourth portion
of ink 50D) may be about 1% to about 70% of the total volume of ink
applied to the composite web 70 during the printing process.
[0038] The ink deposited within the ink zone 44 of the composite
web 70 produces the desired visual signal 60 (FIG. 1). The visual
signal 60 can have an L* value of about +30 to about +90 in the CIE
1976 (L*a*b*) color space, as measured at the outer, or
body-facing, surface 10 of the absorbent article 5. In some
embodiments, the visual signal 60 can have an L* value of about +40
to about +70 in the CIE 1976 (L*a*b*) color space, as measured at
the outer surface of the absorbent article 5. The L* value can be
measured using a Hunter Labscan XE 45/0 geometry reflectance
spectrophotometer. Technical description of the system can be found
in an article by R. S. Hunter, `photoelectric color difference
Meter`, Journal of the Optical Society of America, Vol. 48, pp.
985-95, 1958. Devices that are specially designed for the
measurement of color on the Hunter scales are described in U.S.
Pat. No. 3,003,388 to Hunter et al., issued Oct. 10, 1961. Further,
it has been found that printing on a nonwoven layer of a composite
web 70 that has a relatively low basis weight produces a darker
visual signal 60 (FIG. 1) than a visual signal generated by
printing solely on the nonwoven layer prior to combining it with a
topsheet layer. Darker visual signals 60 are perceived by consumers
as conveying a higher quality image and/or absorbent article. In
some cases, the darkness of the visual signal 60 is comparable to
the darkness of other visual signals that are printed onto
substrates having higher basis weights.
General Description of a Process for Printing on a Composite
Web
[0039] FIG. 6 is a schematic side view of a process 150 for making
and printing on a composite web 70 in accordance with one
non-limiting embodiment. The liquid-permeable topsheet 30 and the
secondary topsheet 20 are provided from storage rolls or from other
parts of the manufacturing process. The secondary topsheet 20 is
directed past an adhesive coater 202 which delivers an adhesive
layer 120 (FIG. 5) to the secondary topsheet 20. The adhesive
coater 202 can be a contact-type applicator or a non-contacting
applicator. Additionally, it should be noted that the adhesive
coater 202 can be replaced by another device for applying joining
means to either the secondary topsheet 20 or the liquid-permeable
topsheet 30. Such may be the case if alternative bonding means are
being used such as ultrasound, heat, pressure or the like. The
secondary topsheet 20 is then sent to a cut-and-slip unit 200, a
cut-and-lay unit (not shown), or other device, as is known in the
art. The liquid-permeable topsheet 30 and the secondary topsheet 20
are then passed through rollers 250 which direct the webs into
face-to-face contact with each other. The liquid-permeable topsheet
30 and the secondary topsheet 20 exit the rollers 250 in a
laminated condition as the composite web 70. The composite web 70
is then directed to a printing unit 204 which delivers a volume of
ink 206 (preferably, but not necessarily, this constitutes the
total volume of ink applied) to the second surface 20B of the
secondary topsheet 20. The composite web 70 can be pulled across an
idler positioned at the printing unit 204 such that ink 206 is
applied to the composite web 70 at any point between perpendicular
(e.g., directly above the idler) to the tangent, or 90 degrees from
perpendicular. This is done to reduce ink blow-through through the
composite web 70 and improve image quality. The composite web 70
can then be directed past an adhesive coater 208 to prepare the
composite web 70 for joining with the top core 22 (or core 90),
which can be provided on a storage roll, as illustrated. In an
alternative process 175, as shown in FIG. 7, the secondary topsheet
20 and the liquid-permeable topsheet 30 are fusion bonded with
rollers 260 to form the composite web 70. Also, the printing unit
204 is positioned to apply the volume of ink 206 at an angle (shown
as print angle .theta.) relative to a position perpendicular (in
this case, vertical) to the composite web 70. The print angle
.theta. can be within the range of about 0 degrees to about 30
degrees, for example, where a 0-degree print angle is perpendicular
to the composite web 70. In other embodiments, the process 150 can
be rotated/oriented 360 degrees such that the printing unit 204
prints upwards, sideways, etc. versus downward as depicted. For
instance, the printing unit 204 may be oriented at 270 degrees
(printing upwards against gravity), however, more reliability
issues due to ink and dust falling back onto the printer may
occur.
[0040] In some embodiments, the ink delivered to the composite web
70 by the printing unit 204 can be in the form of ink drops. One
ink deposit 50 may comprise multiple ink drops. The volume of the
ink drops can depend on the particular printing technology. By way
of example, printing units that are VIDEOJET continuous ink jet
printers can have ink drop volumes of about 240 .rho.L and are
delivered at relatively high drop velocities (e.g., about 13 m/s).
Other printing technology (e.g., piezo drop on demand) can deliver
ink drops having relatively small volumes, such as ink drops having
a volume ranging from about 1 .rho.L to about 24 .rho.L, that are
delivered at lower drop velocities (i.e., about 1/2 m/s) than
continuous inkjet printing. Those skilled in the art know there are
different inkjet technologies (e.g., continuous, piezo, thermal,
valve) and different drop size ranges and different jet velocities.
But, pertaining to printing to a composite web to (1) improve image
quality and (2) minimize line hygiene issues (ink blow-through),
this is how drop size and drop velocity are related. Smaller drop
size infers that the CD dpi (resolution) is higher. The range 1-24
pL would equate to a CD resolution of 300-600 dpi. The VIDEOJET CD
resolution is 128 dpi. So, more drops in CD means better
opportunity to hit a fiber, which results in better image quality
and less ink blow-though. The slower the drop speed, the less ink
blow-through. The smaller drops will be slower due to mass
alone.
[0041] Every document cited herein, including any cross referenced
or related patent or application, is hereby incorporated herein by
reference in its entirety unless expressly excluded or otherwise
limited. The citation of any document is not an admission that it
is prior art with respect to any invention disclosed or claimed
herein or that it alone, or in any combination with any other
reference or references, teaches, suggests or discloses any such
invention. Further, to the extent that any meaning or definition of
a term in this document conflicts with any meaning or definition of
the same term in a document incorporated by reference, the meaning
or definition assigned to that term in this document shall
govern.
[0042] 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
disclosure. It is therefore intended to cover in the appended
claims all such changes and modifications that are within the scope
of this disclosure.
* * * * *