U.S. patent application number 15/696482 was filed with the patent office on 2017-12-21 for sanitary napkin for clean body benefit.
The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to John Lee Hammons, Susan Nicole Lloyd, Stewart Lawrence Taub.
Application Number | 20170360626 15/696482 |
Document ID | / |
Family ID | 54141010 |
Filed Date | 2017-12-21 |
United States Patent
Application |
20170360626 |
Kind Code |
A1 |
Hammons; John Lee ; et
al. |
December 21, 2017 |
SANITARY NAPKIN FOR CLEAN BODY BENEFIT
Abstract
A disposable absorbent article having a facing layer joined to a
backsheet and an absorbent core disposed between the facing layer
and the backsheet, is described herein. The facing layer is a
nonwoven material with a plurality of fibers which have a diameter
of less than 10 microns. The facing layer also has a plurality of
apertures.
Inventors: |
Hammons; John Lee;
(Hamilton, OH) ; Lloyd; Susan Nicole; (Erlanger,
KY) ; Taub; Stewart Lawrence; (Needham, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Family ID: |
54141010 |
Appl. No.: |
15/696482 |
Filed: |
September 6, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14217679 |
Mar 18, 2014 |
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15696482 |
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13219085 |
Aug 26, 2011 |
8704036 |
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14217679 |
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10720557 |
Nov 24, 2003 |
8030535 |
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13219085 |
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60434792 |
Dec 18, 2002 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 13/512 20130101;
A61F 13/513 20130101; A61F 2013/51344 20130101; A61F 13/51108
20130101; A61F 13/51104 20130101; A61F 13/5116 20130101; A61F
13/511 20130101; A61F 2013/51338 20130101; A61F 2013/51182
20130101 |
International
Class: |
A61F 13/512 20060101
A61F013/512; A61F 13/511 20060101 A61F013/511 |
Claims
1. A disposable absorbent article having a longitudinal axis
defining a longitudinal orientation and longitudinally-oriented
side edges, a transverse axis orthogonal to the longitudinal axis,
a thickness measured orthogonal to a plane defined by the
longitudinal axis and the transverse axis, and peripheral edges,
the disposable absorbent article comprising: a facing layer joined
to a backsheet, and an absorbent core disposed between the facing
layer and the backsheet, wherein the facing layer comprises a
nonwoven material comprising a plurality of fibers which have a
diameter of less than 10 microns, the facing layer further
comprising a plurality of apertures.
2. The disposable absorbent article of claim 1, wherein the facing
layer further comprises a first region disposed centrally to the
disposable absorbent article along said longitudinal axis, said
first region does not extend to any of said peripheral edges.
3. The disposable absorbent article of claim 2, wherein the facing
layer further comprises a second region comprising a plurality of
out-of-plane deformations.
4. The disposable absorbent article of claim 3, wherein said
out-of-plane deformations are soft, resilient, textured wipers.
5. The disposable absorbent article of claim 3, wherein said
out-of-plane deformations are soft, resilient, rib-like
elements.
6. The disposable absorbent article of claim 5, wherein said
rib-like elements are longitudinally-oriented.
7. The disposable absorbent article of claim 1, further comprising
a deep-embossed channel.
8. The disposable absorbent article of claim 7, wherein said
deep-embossed channel has a depth of at least 50% of said thickness
of said disposable absorbent article.
9. The disposable absorbent article of claim 1, wherein said facing
layer comprises a composite web material comprising a second
plurality of fibers which have an average diameter of greater than
7 microns.
10. The disposable absorbent article of claim 9, wherein the second
plurality of fibers have an average diameter of between about 10
microns to about 40 microns.
11. The disposable absorbent article of claim 9, wherein the second
plurality of fibers are bicomponent fibers.
12. The disposable absorbent article of claim 10, wherein the
second plurality of fibers are bicomponent fibers.
13. The disposable absorbent article of claim 1, wherein the facing
layer comprises a composite material comprising a topsheet and a
secondary topsheet, wherein the topsheet and the secondary topsheet
are in intimate contact with one another via mechanical
manipulation of the composite web.
14. The disposable absorbent article of claim 3, wherein said
second region is disposed adjacent at least one of said
longitudinally-oriented side edges and adjacent said first region
of said facing layer.
15. The disposable absorbent article of claim 1, wherein the facing
layer comprises a first layer and a second layer, and wherein at
least one of the first layer or the second layer is apertured.
Description
FIELD OF INVENTION
[0001] This invention relates to catamenial products such as
sanitary napkins. In particular, this invention relates to
body-facing layers for sanitary napkins that improve fluid
acquisition and result in the wearer having a clean body.
BACKGROUND OF THE INVENTION
[0002] Body-facing layers of disposable absorbent products such as
sanitary napkins, disposable diaper, and adult incontinence
products are well known in the art. Body-facing layers are
sometimes referred to as facing layers, and more commonly are
referred to as topsheets.
[0003] Topsheets on disposable absorbent articles are fluid
pervious sheets or webs; commonly nonwoven webs are utilized.
Nonwoven webs provide fluid permeability along with softness.
Although a nonwoven web can be used "as is" in many cases, it is
often important to modify the nonwoven web for a particular
purpose. For example, nonwoven webs for topsheets can be apertured,
corrugated, or treated with fluid flow-modifying agents such as
surfactants.
[0004] U.S. Pat. Nos. 5,916,661 and 5,628,097, both issued to Curro
et al., disclose an apertured nonwoven web, and a method for making
the web. This web has been found to be useful as a topsheet on
disposable diapers, for example, by permitting viscous body
exudates a pathway to an absorbent core within the diaper.
[0005] U.S. Pat. No. 5,518,801 issued to Chappell et al. discloses
a process for forming a web, including laminates of webs, the
process forming rib-like elements in a web. Such a process is
disclosed as producing elastic-like webs from films, and the like.
The elastic-like webs are formed by passing a web through the nip
of a pair of intermeshing rolls that form the rib-like
elements.
[0006] Both apertured and elastic-like webs made according to the
processes disclosed in the above-mentioned Curro et al. and
Chappell et al. patents have been disclosed separately for use in
topsheets for disposable absorbent articles. However, there remains
a need for topsheets effective in keeping the body of the wearer
clean during use.
[0007] Accordingly, there is a need for a topsheet that is
effective at absorbing body exudates, and at cleaning the skin of
the wearer of any body exudates that remain on the skin during
use.
SUMMARY OF THE INVENTION
[0008] A sanitary napkin has a facing layer joined to a backsheet,
and an absorbent core disposed between the facing layer and
backsheet. The facing layer has a first region comprising a
plurality of apertures, and a second region comprising a plurality
of raised, out-of-plane deformations that can be soft, resilient,
rib-like elements. In one embodiment, the sanitary napkin also
comprises a deep-embossed channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a plan view of a sanitary napkin of the present
invention.
[0010] FIG. 2 is cross sectional view of Section 2-2 of FIG. 1.
[0011] FIG. 3 is a perspective view of an apparatus for making the
present invention.
[0012] FIG. 4 is a plan view of a sanitary napkin of the present
invention having deep-embossed channels.
[0013] FIG. 5 is a plan view of a sanitary napkin of the present
invention having deep-embossed channels.
[0014] FIG. 6 is cross sectional view of Section 6-6 of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIG. 1 shows in partial cut away plan view one embodiment of
a sanitary napkin 20 of the present invention comprising a
backsheet 22, a facing layer 1, and an absorbent core 24 disposed
between the facing layer 1 and backsheet 22 which can be joined
about a their periphery 21. Facing layer 1 can comprise a topsheet
26 alone, or together with a secondary topsheet 27 adjacent to and
in contact with topsheet 26. Sanitary napkin 20 can have side
extensions, commonly referred to as "wings" 28, designed to wrap
the sides of the crotch region of the panties of the user of
sanitary napkin 20. Wings 28 typically have fastening means (not
shown) to releasably affix the sanitary napkin 20 to the panty.
[0016] Facing layer 1 of sanitary napkin 20 is a body-facing layer
having a first region 2 and a second region 3, the two regions
being differentiated by the kind of deformations 6 disposed in
each. Facing layer 1 may comprise a topsheet 26 as is commonly
known in the art, and it can be a composite comprising both
topsheet 26 and secondary topsheet 27, also as known in the art.
Sanitary napkins, including topsheets and secondary topsheets for
use as the body facing surface thereof, are well known in the art
and need no detailed description of various alternative and
optional components and designs, all of which can form a part of
the present invention.
[0017] Deformations 6 comprise apertures 8 and out-of-plane
deformations 10 can be rib-like elements 10, each of which are
important to providing the benefit of facing layer 1. In
particular, apertures 8 are disposed in, and extend through, first
region(s) 2 of the facing layer 1 and are sufficiently large (e.g.,
at least about 1 to 2 mm.sup.2 each) to permit more viscous fluids,
such as menses, to flow through the facing layer 1 and into
absorbent core 24. First region 2, therefore, is preferably
disposed generally centrally to sanitary pad 20, preferably along a
centrally-disposed longitudinal axis L and at or near the junction
of the L axis and a centrally disposed transverse axis T.
Longitudinal axis L and transverse axis T define a two-dimensional
plane of the sanitary napkin, which, in the embodiment shown is
associated with the machine direction (MD) and cross machine
direction (CD) as is commonly known in the art of making sanitary
napkins in continuous processes.
[0018] Out-of-plane deformations 10 are disposed in second region 3
of facing layer 1. In general, by "out-of-plane" is meant extending
in the "Z"-direction, as indicated by FIG. 2. In FIG. 2
out-of-plane deformations 10 are shown in exaggerated proportion,
although there are not believed to be particular dimensional
limitations. The only design considerations with respect to the
dimensions of out-of-plane deformations 10 are those related to the
comfort to the wearer. It may be that for particular facing layers
1 the height (Z-direction) of out-of-plane deformations 10 can be
uniform; in other embodiments the height can vary, such as by
increasing with increasing outboard distance from longitudinal
centerline L. In one embodiment, out-of-plane deformations 10 are
disposed generally outboard of first region 2, as shown in FIG.
1.
[0019] Out-of-plane deformations 10 can be rib-like elements, as
shown in FIGS. 1 and 2. As such, out-of-plane deformations 10 can
comprise raised ridges of a pre-defined length that is much shorter
than the length of the sanitary napkin, measured along the
longitudinal centerline, for example. In one embodiment as shown in
FIG. 1, out-of-plane deformations 10 are disposed in a regular
pattern of rib-like elements that form a pattern of diamond-shapes,
each diamond shape being comprised of a plurality of rib-like
elements. In this manner, the out-of-plane deformations 10 also
contribute to softness and flexibility, as well as providing for
improved visual perception of comfort. In general, the individual
rib-like elements can have a length, measured along their
longitudinal orientation, of between 1% and 50% of the length of
the sanitary napkin, measured along the longitudinal axis. In a
preferred embodiment, the individual rib-like elements can have a
length of between 10% and 20% of the length of the sanitary napkin,
with a spacing in the L-T plane such that there is not a straight
path from any portion of the first region 2 to either of the
longitudinal side edges of sanitary napkin 20.
[0020] In a preferred embodiment, first region 2 is disposed
generally centrally with respect to the sanitary napkin. As shown
in FIGS. 1-6, first region 2 can be disposed centrally and
generally symmetrically with respect to the longitudinal axis L and
transverse axis T. Second region 3 is preferably disposed outboard
of first region 2 preferably in an area extending from first region
2 to an area adjacent longitudinal side edges of the sanitary
napkin 20.
[0021] In general, the facing layer 1 can comprise nonwoven
materials as are known in the art for topsheets on disposable
absorbent articles. Absorbent core 24 and backsheet 22 can likewise
comprise absorbent materials, and film materials, respectively, as
is well known in the art. Secondary topsheet 27 (if used) can be a
distribution layer that serves to distribute fluid in the
directions of MD and CD. Wings, if used, can be integral extensions
of the topsheet or the backsheet or both, and they can be symmetric
about the longitudinal axis L, transverse axis T, or both.
[0022] The clean body benefit of the present invention is in part
due to apertures 8 and out-of-plane deformations 10 that form
discrete regions of facing layer 1. Apertures 8 provide for
relatively unimpeded fluid flow of viscous fluid having a
percentage of solids content, such as menstrual fluid. Raised,
out-of-plane deformations 10 are a plurality of individual fluid
barriers, each effective in retarding any free fluid flow that may
have a tendency to run off the facing layer 1 when sanitary napkin
20 is used, without becoming a total block of fluid distribution to
outboard portions of the sanitary napkin 20. In addition
out-of-plane deformations 10 are soft, resilient, textured wipers
to help keep the skin surfaces of the wearer clean.
[0023] As shown in FIG. 2, apertures 8 permit fluid communication
between a body-contacting surface 9 of facing layer 1, and a second
surface 11 of facing layer 1. Typically, second surface 11 is in
contact with absorbent core 24 to effect efficient fluid flow into
the core 24. Fluid typically flows from the body source in the
direction of arrows F when the sanitary napkin is in use. However,
it can be appreciated that menstrual fluid does not necessarily
flow straight down in a gush, but, rather it flows out in contact
with the wearer's skin onto the surface of the sanitary napkin. For
this reason, it is important that fluid that otherwise has a
tendency to follow the skin rather than enter the pad, be urged
into the pad. It is believed that the raised, out-of-plane
deformations 10 serves as a plurality of discrete wipers to urge,
i.e., to wipe, fluid off the body and into the pad during use.
[0024] Additionally, since menses can have a substantial solids
content, and can be relatively non-Newtonian, i.e., having a high
viscosity relative to other fluids such as urine, the apertures 8
and out-of-plane deformations 10 aid in effective menses absorption
into an absorbent core. Out-of-plane deformations 10 can act as
barriers to prevent menses from migrating along the wearer's skin,
and apertures 8 permit penetration of solids through facing layer
1.
[0025] It can also be appreciated with reference to FIG. 2 that
fluid having a tendency to run off the facing layer 1 in the CD
direction will be impeded by raised, out-of-plane deformations 10
generally disposed along the longitudinal side edges of sanitary
napkin 20. Although all the raised, out-of-plane deformations 10
are shown as being aligned longitudinally in the MD, this is just a
currently preferred embodiment. In practice, raised, out-of-plane
deformations 10 could be oriented otherwise.
[0026] In the preferred embodiments shown, apertures 8 and raised,
out-of-plane deformations 10 are shown in a longitudinally-aligned
orientations. This is due to the preferred method for making, as
disclosed below. But it is recognized that other patterns of
apertures and deformations are within the scope of the invention,
including, for example, a discrete region in the center of the pad
having apertures, the discrete region not extending to any of the
peripheral edges. Also, apertures and deformations could be in a
stripe pattern with the stripes generally transversely aligned.
[0027] FIG. 2 shows a two-layer facing layer 1 having a topsheet 26
layer and a secondary topsheet 27 layer. It is recognized that the
facing layer 1 need not be limited to any particular number of
layers, and can have only one, or it can have three or more.
[0028] Without being bound by theory, it is believed that superior
fluid acquisition is obtained by having the topsheet 26 layer and
the secondary topsheet 27 layer intimately contacting one another
by processing the two together as a composite web material by the
method disclosed below. In this manner, the topsheet 26 and the
secondary topsheet 27 become somewhat intermeshed and function as a
single facing layer 1.
[0029] FIG. 3 shows a method for making facing layer 1 of the
present invention that is suitable for use on sanitary napkin 20.
Facing layer 1 is formed from a generally planar, two dimensional
nonwoven precursor web 200 on apparatus 100, the apparatus
preferably being oriented for continuous web processing with
respect to a machine direction (MD) and a cross machine direction
(CD) as is commonly known in the art of nonwoven webs. Precursor
web 200 has formed therein in predetermined regions a plurality of
melt-weakened portions 115 prior to entering nip 116. Melt-weakened
portions are formed in predetermined regions of web 200 by thermal
point calendaring in the predetermined regions, the predetermined
regions corresponding to first region(s) 2 of facing layer 1, that
is, the region where apertures are ultimately desired. Each
melt-weakened portion of the predetermined region is generally
elongated and oriented in the MD. Upon stretching in the CD in the
portion of the apparatus 100 corresponding to the region 113, the
melt-weakened portions rupture to form apertures 8. In one
embodiment, the melt-weakened portions 115 are limited to the
central region of web 200, that is, the region corresponding to the
central first region 2 of sanitary napkin 20 in FIG. 1.
[0030] The apparatus 100 comprises a pair of rolls 102 and 104,
each rotating about parallel axes A, and is similar in many
respects to the apparatuses described in the above-mentioned U.S.
Pat. Nos. 5,916,661 and 5,628,097, and U.S. Pat. No. 5,518,801
issued to Chappell et al., each of which are hereby incorporated
herein by reference. The primary difference is the combination in
one apparatus the benefit of aperture-forming rolls as taught in
U.S. Pat. Nos. 5,916,661 and 5,628,097, and rib-like
element-forming rolls as taught in U.S. Pat. No. 5,518,801. By
combining both into one apparatus to form both apertures and
rib-like elements in one facing layer 1, the sanitary napkin of the
present invention provides for significant benefits over prior art
sanitary napkins. In particular, the sanitary napkin of the present
invention is better at keeping the body of the wearer clean than
previously-known sanitary napkins. It is believed that the
apertures 8 of facing layer permit rapid acquisition of menses into
the core 24, and the rib-like elements 10 serve to stop lateral
fluid flow. As well, rib-like elements 10 serve as a plurality of
"wipers" to constantly wipe the skin with the body movements of the
wearer.
[0031] The apparatus 100 shown in FIG. 3 comprises a roll 102
comprising a plurality of circumferentially-extending ridges 106
separated by grooves 108, as disclosed in the above-mentioned
patents and as well known in the art of "ring-rolling". A second,
intermeshing roll 104 comprises a first region 113 having
essentially matching roll 102 and having ridges 106 separated by
grooves 108. The intermeshing ridges 106 and grooves 108 of rolls
102 and 104 incrementally stretch precursor web 200 to form
apertures 8 as disclosed in U.S. Pat. Nos. 5,916,661 and 5,628,097.
Of course, precursor web 200 has melt-weakened regions 115 formed
therein prior to precursor web 200 entering the nip 116 of
apparatus 100.
[0032] In addition to region 113, roll 104 has two regions 111
comprising ridges having formed therein teeth 110, the toothed
ridges separated by grooves 112. Ridges 106 of roll 102 intermesh
with the grooves 112 of roll 104 to form the rib-like elements 10
of second region(s) 3.
[0033] In this manner a web suitable for a facing layer 1 is
produced, the facing layer 1 having both first regions 2 and second
regions 3 comprising apertures 8 and rib-like elements 10,
respectively, and suitable for use on a sanitary napkin, as shown
in FIG. 1. Facing layer 1 has a first region 2 defined on both
sides of facing layer 1 by having a plurality of spaced apart
apertures 8. A second region 3 is defined by a plurality of
spaced-apart rib-like elements 10 which are integral extensions of
the fibers of the precursor web 200.
[0034] One advantage of the apparatus described above is that the
facing layer can be produced in-line with other production
equipment on a manufacturing line for producing disposable
absorbent articles. For example, an apparatus such as the
above-disclosed thermal point calendaring rolls for making
melt-weakened portions 115 and the pair of rolls 102 and 104, can
be made as a unit operation that can be inserted into an existing
manufacturing line. As unit operations themselves, such apparatuses
can be modular such that they can be changed out relatively quickly
and easily with other modular unit operations. When used as part of
a manufacturing line for sanitary napkins, for example, the
constituent rollers need not be much wider than the product itself,
thereby providing for relatively quick and easy installation and
removal. Various patterns of first region 2 and second region 3 can
therefore be implemented with a minimum of manufacturing line
interruption.
[0035] In one embodiment, the facing layer 1 of the present
invention can have a lotion applied thereto to provide even more
and better benefits. In one embodiment a lotion as disclosed in
co-pending U.S. application Ser. No. 10/262,036, filed Oct. 1,
2002, which is hereby incorporated herein by reference.
[0036] Apertures 8, and discrete raised, out-of-plane deformations
10 serve to add significant extensibility to facing layer 1. For
example, it has been found that sanitary napkins of the present
invention having significant caliper (thickness) due, for example,
to a relatively thick absorbent core, can have deep-embossed
channels produced therein, the channels having a tendency to stay
deep-embossed.
[0037] As shown in FIGS. 4-6, a channel 5 can be deep-embossed into
sanitary napkin 20. Embossing facing layer 1 deep into absorbent
core 24 provides for a fluid-impeding channel that helps contain
fluid flow, and, as well, adds to the aesthetic appearance of the
sanitary napkin 20. In prior art sanitary napkins, deep-embossing
is often not effective due to the lack of channel retention during
packaging, storage, or use. It is believed that the elastic tension
of a normal topsheet works to slowly pull the embossing out after
it is put in. The inherent extensibility of the facing layer 1 of
the present invention, however, permits significant extension of
the facing layer 1 into the deep-embossed channel 5, with little or
no restoring force present.
[0038] Also as shown in FIGS. 4 and 5, the deep-embossed channel 5
can define at least one interior portion which is the portion of
the sanitary napkin circumscribed by the channel 5. In the
embodiment shown in FIG. 5, for example, three interior portions
are defined by channel 5. In a preferred embodiment, the first
region is disposed substantially within the interior portion(s)
defined by channel 5.
[0039] As shown in cross section in FIG. 6, the deep embossed
channels can significantly compress the absorbent core 24 in the
region of channel(s) 5. This provides for additional fluid
containment near the central portion of sanitary napkin 20.
[0040] By way of example, deep embossed channels 5 can have a depth
dimension in the Z-direction of at least about 50% of the caliper
(thickness in the Z-direction) of the sanitary napkin 20, more
preferably about 60%, 70%, 80% or 90% of the caliper. Thus, if the
caliper of the sanitary napkin 20 is 10 mm, the depth of embossment
of channel(s) 5 can be 6 mm, 7 mm, 8 mm, or 9 mm Caliper and depth
dimensions can be average dimensions if either are not consistent
across the entire sanitary napkin.
[0041] As shown in FIG. 4, in one embodiment facing sheet 1 does
not comprise apertures. In this embodiment, the raised,
out-of-plane deformations 10 provide sufficient extensibility to
facing sheet 1 to permit the formation and retention of
deep-embossed channels 5.
[0042] By "retention" of deep-embossed channels 5 is meant that
after being packaged and/or used, the channels 5 retain at least
50% of their original depth dimension, more preferably 60%, 70%,
80%, 90% or 100%. Depth can be measured by any techniques known in
the art, including by simple digital depth gauge, using an average
depth if depth is variable over the length of channels 5.
[0043] Nonwoven precursor webs 200 can be any known nonwoven webs
or composites of two or more nonwoven webs, each comprising fibers
having sufficient mechanical (e.g., elongation) properties to be
formed into web 1 as described more fully below. Fibers can be
monocomponent, bicomponent, biconstituent, or capillary channel
fibers.
[0044] As used herein, the term "nonwoven web" refers to a web
having a structure of individual fibers or threads which are
interlaid, but not in an identifiable manner as in a woven or
knitted fabric. Nonwoven webs or fabrics have been formed from many
processes, such as, for example, meltblowing processes, spunbonding
processes, and bonded carded web processes. The basis weight of
nonwoven fabrics is usually expressed in grams per square meter
(gsm) and the fiber diameters are usually expressed in microns.
Fiber size can also be expressed in denier. The basis weight of
precursor web 200 (which can be a single layer or a composite of
more than one layer) can range from 10 gsm to 200 gsm, depending on
the ultimate use of the web 1.
[0045] The constituent fibers of nonwoven precursor web 200 can be
polymer fibers, and can be monocomponent, bicomponent, and/or
biconstituent, capillary channel fibers, and can have major
cross-sectional dimensions (e.g., diameter for round fibers)
ranging from 5-200 microns. The constituent fibers can range from
about 0.1 denier to about 100 denier.
[0046] As used herein, "spunbond fibers" refers to small diameter
fibers which are formed by extruding molten thermoplastic material
as filaments from a plurality of fine, usually circular capillaries
of a spinneret with the diameter of the extruded filaments then
being rapidly reduced. Spunbond fibers are generally not tacky when
they are deposited on a collecting surface. Spunbond fibers are
generally continuous and have average diameters (from a sample of
at least 10) larger than 7 microns, and more particularly, between
about 10 and 40 microns.
[0047] As used herein, the term "meltblowing" refers to a process
in which fibers are formed by extruding a molten thermoplastic
material through a plurality of fine, usually circular, die
capillaries as molten threads or filaments into converging high
velocity, usually heated, gas (for example air) streams which
attenuate the filaments of molten thermoplastic material to reduce
their diameter, which may be to microfiber diameter. Thereafter,
the meltblown fibers are carried by the high velocity gas stream
and are deposited on a collecting surface, often while still tacky,
to form a web of randomly dispersed meltblown fibers. Meltblown
fibers are microfibers which may be continuous or discontinuous and
are generally smaller than 10 microns in average diameter.
[0048] As used herein, the term "polymer" generally includes, but
is not limited to, homopolymers, copolymers, such as for example,
block, graft, random and alternating copolymers, terpolymers, etc.,
and blends and modifications thereof. In addition, unless otherwise
specifically limited, the term "polymer" includes all possible
geometric configurations of the material. The configurations
include, but are not limited to, isotactic, atactic, syndiotactic,
and random symmetries.
[0049] As used herein, the term "monocomponent" fiber refers to a
fiber formed from one or more extruders using only one polymer.
This is not meant to exclude fibers formed from one polymer to
which small amounts of additives have been added for coloration,
antistatic properties, lubrication, hydrophilicity, etc. These
additives, for example titanium dioxide for coloration, are
generally present in an amount less than about 5 weight percent and
more typically about 2 weight percent.
[0050] As used herein, the term "bicomponent fibers" refers to
fibers which have been formed from at least two different polymers
extruded from separate extruders but spun together to form one
fiber. Bicomponent fibers are also sometimes referred to as
conjugate fibers or multicomponent fibers. The polymers are
arranged in substantially constantly positioned distinct zones
across the cross-section of the bicomponent fibers and extend
continuously along the length of the bicomponent fibers. The
configuration of such a bicomponent fiber may be, for example, a
sheath/core arrangement wherein one polymer is surrounded by
another, or may be a side-by-side arrangement, a pie arrangement,
or an "islands-in-the-sea" arrangement.
[0051] As used herein, the term "biconstituent fibers" refers to
fibers which have been formed from at least two polymers extruded
from the same extruder as a blend. The term "blend" is defined
below. Biconstituent fibers do not have the various polymer
components arranged in relatively constantly positioned distinct
zones across the cross-sectional area of the fiber and the various
polymers are usually not continuous along the entire length of the
fiber, instead usually forming fibrils which start and end at
random. Biconstituent fibers are sometimes also referred to as
multiconstituent fibers.
[0052] As used herein, the term "capillary channel fibers" refers
to fibers having capillary channels. Such fibers can be hollow
fibers, for example, but are preferably fibers having capillary
channels on their outer surfaces. The capillary channels can be of
various cross-sectional shapes such as "U-shaped", "H-shaped",
"C-shaped" and "V-shaped".
[0053] While various preferred embodiments of the invention have
been disclosed herein, such embodiments are not intended to limit
the scope of the invention. As can be understood from the above
description of sanitary napkin 20 of the present invention, many
various structures can be made without departing from the scope of
the present invention as claimed in the appended claims.
[0054] 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.
[0055] 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 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.
* * * * *