U.S. patent application number 10/382231 was filed with the patent office on 2003-12-18 for method for improved aperture clarity in three-dimensional nonwoven fabrics and the products thereof.
This patent application is currently assigned to Polymer Group, Inc.. Invention is credited to Carlyle, Thomas, Moody, Ralph A. III, Putnam, Michael J., Rivera, Miguel.
Application Number | 20030232558 10/382231 |
Document ID | / |
Family ID | 27805146 |
Filed Date | 2003-12-18 |
United States Patent
Application |
20030232558 |
Kind Code |
A1 |
Moody, Ralph A. III ; et
al. |
December 18, 2003 |
Method for improved aperture clarity in three-dimensional nonwoven
fabrics and the products thereof
Abstract
The present invention is directed a nonwoven fabric which is
imparted with a three-dimensional image or pattern, and apertures
essentially devoid of fiber, during the fabrication stage. The
nonwoven fabric exhibits a fibrous extension out of the plane of
the material, while apertures are present that have a pronounced
uniformity and a significant reduction in fibrous occlusion.
Inventors: |
Moody, Ralph A. III;
(Mooresville, NC) ; Putnam, Michael J.;
(Fuquay-Varina, NC) ; Carlyle, Thomas;
(Huntersville, NC) ; Rivera, Miguel; (Mooresville,
NC) |
Correspondence
Address: |
WOOD, PHILLIPS, KATZ, CLARK & MORTIMER
500 W. MADISON STREET
SUITE 3800
CHICAGO
IL
60661
US
|
Assignee: |
Polymer Group, Inc.
|
Family ID: |
27805146 |
Appl. No.: |
10/382231 |
Filed: |
March 5, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60362225 |
Mar 6, 2002 |
|
|
|
Current U.S.
Class: |
442/327 ;
442/408 |
Current CPC
Class: |
D04H 1/49 20130101; Y10T
442/689 20150401; D04H 1/495 20130101; D04H 1/70 20130101; Y10T
442/60 20150401 |
Class at
Publication: |
442/327 ;
442/408 |
International
Class: |
D04H 001/46; D04H
005/02 |
Claims
What is claimed is:
1. A nonwoven fabric, comprising; a prebond fibrous matrix of
staple length fibers, a three-dimensional transfer device,
hydroentangling the prebond fibrous matrix on the three-dimensional
transfer device so as to impart a three-dimensional and at least
one aperture into the resultant nonwoven fabric, and the
three-dimensional nonwoven fabric exhibiting a bulk of at least 1.5
millimeters and a clarity of aperture of at least 0.06.
2. A nonwoven fabric, comprising; a prebond fibrous matrix of
staple length fibers, a three-dimensional transfer device,
hydroentangling the prebond fibrous matrix on the three-dimensional
transfer device so as to impart a three-dimensional and at least
one aperture into the resultant nonwoven fabric, and the
three-dimensional nonwoven fabric exhibiting a bulk of at least 1.5
millimeters and a clarity of aperture wherein the area of the apex
of a graphical projection is greater than 50% of the area at the
base of the projection when measured in a Photometric Analysis.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application Serial No. 60/362,225, filed Mar. 6, 2002.
TECHNICAL FIELD
[0002] The present invention relates generally to a nonwoven
fabric, and specifically to a nonwoven fabric imparted with a
three-dimensional pattern, said three-dimensional pattern further
including at least one aperture, wherein the aperture exhibits a
pronounced uniformity and significant reduction of fibrous
occlusion.
BACKGROUND OF THE INVENTION
[0003] The production of conventional textile fabrics is known to
be a complex, multi-step process. The production of fabrics from
staple fibers begins with the carding process where the fibers are
opened and aligned into a feedstock known as sliver. Several
strands of sliver are then drawn multiple times on a drawing frames
to further align the fibers, blend, improve uniformity as well as
reduce the sliver's diameter. The drawn sliver is then fed into a
roving frame to produce roving by further reducing its diameter as
well as imparting a slight false twist. The roving is then fed into
the spinning frame where it is spun into yarn. The yarns are next
placed onto a winder where they are transferred into larger
packages. The yarn is then ready to be used to create a fabric.
[0004] For a woven fabric, the yarns are designated for specific
use as warp or fill yarns. The fill yarns (which run on the y-axis
and are known as picks) are taken straight to the loom for weaving.
The warp yarns (which run on the x-axis and are known as ends) must
be further processed. The large packages of yarns are placed onto a
warper frame and are wound onto a section beam were they are
aligned parallel to each other. The section beam is then fed into a
slasher where a size is applied to the yarns to make them stiffer
and more abrasion resistant, which is required to withstand the
weaving process. The yarns are wound onto a loom beam as they exit
the slasher, which is then mounted onto the back of the loom. The
warp yarns are threaded through the needles of the loom, which
raises and lowers the individual yarns as the filling yarns are
interested perpendicular in an interlacing pattern thus weaving the
yarns into a fabric. Once the fabric has been woven, it is
necessary for it to go through a scouring process to remove the
size from the warp yarns before it can be dyed or finished.
Currently, commercial high-speed looms operate at a speed of 1000
to 1500 picks per minute, where a pick is the insertion of the
filling yarn across the entire width of the fabric. Sheeting and
bedding fabrics are typically counts of 80.times.80 to
200.times.200, being the ends per inch and picks per inch,
respectively. The speed of weaving is determined by how quickly the
filling yarns are interlaced into the warp yarns; therefore looms
creating bedding fabrics are generally capable of production speeds
of 5 inches to 18.75 inches per minute.
[0005] In contrast, the production of nonwoven fabrics from staple
fibers is known to be more efficient than traditional textile
processes as the fabrics are produced directly from the carding
process.
[0006] Nonwoven fabrics are suitable for use in a wide variety of
applications where the efficiency with which the fabrics can be
manufactured provides a significant economic advantage for these
fabrics versus traditional textiles. However, nonwoven fabrics have
commonly been disadvantaged when fabric properties are compared,
particularly in terms of surface abrasion, pilling and durability
in multiple-use applications. Hydroentangled fabrics have been
developed with improved properties, which are a result of the
entanglement of the fibers, or filaments in the fabric providing
improved fabric integrity. Subsequent to entanglement, fabric
durability can be further enhanced by the application of binder
compositions and/or by thermal stabilization of the entangled
fibrous matrix.
[0007] U.S. Pat. No. 3,485,706, to Evans, hereby incorporated by
reference, discloses processes for effecting hydroentanglement of
nonwoven fabrics. More recently, hydroentanglement techniques have
been developed which impart images or patterns to the entangled
fabric by effecting hydroentanglement on three-dimensional image
transfer devices. Such three-dimensional image transfer devices are
disclosed in U.S. Pat. No. 5,098,764, hereby incorporated by
reference, with the use of such image transfer devices being
desirable for providing a fabric with enhanced physical properties
as well as an aesthetically pleasing appearance.
[0008] Over the years, the use of nonwoven fabrics specifically in
cleaning applications has been well practiced. Suitable substrates
have included sponges, woven and nonwoven fabrics, and various
combinations thereof. Further, such substrates have been
impregnated with cleaning agents such as astringents, solvents,
detergents and other chaotropes. The resulting cleaning products
fabricated from such impregnated substrates have found acceptance
with the general public as a convenient and practical means for the
cleaning of surfaces. In particular, such constructs have been
reasonably successful in the facial cleansing market.
[0009] Substrates of particular importance in the facial cleansing
market include those fabrics that are imparted with apertures, or
otherwise exhibit regions devoid of substrate matrix. It is has
been conjectured by the fabricators of facial cleansing products
practicing the use of such apertured fabric that the presence of
the apertures improve the ability of the substrate to quickly build
a beneficial lather during the cleansing process.
[0010] The presence of apertures in a facial cleansing product has
been found to be a difficult and complex material to fabricate due
to a need to have an absolute minimum in the occurrences of
occluded apertures. Occlusion, for example by the fibrous matrix of
a nonwoven substrate, and non-uniformity of the aperture has
multiple deleterious affects. First, the occlusion results in an
expected reduction of efficacy during a lather generation procedure
due to the further constriction of the occlusion by the buildup of
applied detergent agents. Second, an apertured substrate is
difficult to fabricate so as to be functional and at the same time
aesthetically pleasing. The very real problem of aesthetic appeal
to the end-user is based on the fact that the human eye is
attracted to variation in repeating patterns. An intermittent
occlusion, even if only subtle in degree, will result in the user
perception of a low quality product. The need for uniformity of
aperture must be anticipated during the fabrication process and
substrate material rejected should the aperture clarity at any time
fall outside of predetermined specifications, thus leading to an
exceedingly high level of potential material being rejected.
[0011] There remains a need for a nonwoven fabric which exhibits a
combination of three-dimensionality and at least one aperture, and
which does not suffer from the inherent problems of aperture
occlusion.
SUMMARY OF THE INVENTION
[0012] The present invention is directed a nonwoven fabric which is
imparted with a three-dimensional image or pattern, and apertures
essentially devoid of fiber, during the fabrication stage. The
nonwoven fabric exhibits a fibrous extension out of the plane of
the material, while apertures are present that have a pronounced
uniformity and a significant reduction in fibrous occlusion.
[0013] The uniformity and significant reduction in fiber occlusion
have heretofore been unattainable in a three-dimensionally imaged
or patterned nonwoven fabric. The nonwoven fabric of the present
invention has a bulk of at least 1.5 millimeters and a clarity of
opening value of 0.06 or less, and preferably a bulk of at least
1.8 millimeters and a clarity of opening value of 0.055 or less,
and most preferably, a bulk of 2.0 millimeters and a clarity of
opening value of 0.05 or less.
[0014] In accordance with the present invention, a method of making
the nonwoven fabric embodying the present invention includes the
steps of providing a precursor web comprising a fibrous matrix. In
a particularly preferred form, the fibrous matrix is carded and
cross-lapped to form a precursor web. It is also preferred that the
precursor web be subjected to pre-entangling on a foraminous
forming surface prior to imaging and patterning.
[0015] A method of making the present durable nonwoven fabric
comprises the steps of providing a precursor web, which is
subjected to hydroentangling. The precursor web is formed into an
imaged and patterned nonwoven fabric by hydroentanglement on a
three-dimensional image transfer device. The image transfer device
defines three-dimensional elements against which the precursor web
is forced during hydroentangling, whereby the fibrous constituents
of the web are imaged and patterned by movement into regions
between the three-dimensional elements of the transfer device.
Apertures are induced by pronounced surface asperities that extend
out of the plane of the image transfer device. The formation of the
aperture-inducing asperities, and the associated fluidic drainage,
is controlled such that a recessed region peripheral to each of the
asperities aids in redirecting the fibrous matrix of the substrate
down and into the recessed region.
[0016] In the preferred form, the precursor web is hydroentangled
on a foraminous surface prior to hydroentangling on the image
transfer device. This pre-entangling of the precursor web acts to
integrate the fibrous components of the web, but does not impart
imaging and patterning as can be achieved through the use of the
three-dimensional image transfer device.
[0017] Other features and advantages of the present invention will
become readily apparent from the following detailed description,
the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a diagrammatic view of an apparatus for
manufacturing a nonwoven fabric, embodying the principles of the
present invention;
[0019] FIG. 2 is a plan view of a three-dimensional image transfer
device of the type used for practicing the present invention;
[0020] FIG. 3 is a plan view of a three-dimensional nonwoven
fabric, made using conventional image transfer practices; the
magnification level is about 6.5.times.;
[0021] FIG. 4 is a plan view of a three-dimensional nonwoven
fabric, made in accordance with the present invention, the
magnification level is about 6.5.times.;
[0022] FIGS. 5a and 5b are luminosity plots of the nonwoven fabric
depicted in FIG. 3; and
[0023] FIGS. 6a and 6b are luminosity plots of the nonwoven fabric
depicted in FIG. 4.
DETAILED DESCRIPTION
[0024] While the present invention is susceptible of embodiment in
various forms, there is shown in the drawings and will hereinafter
be described a presently preferred embodiment of the invention,
with the understanding that the present disclosure is to be
considered as an exemplification of the invention, and is not
intended to limit the invention to the specific embodiment
illustrated.
[0025] The present invention is directed a nonwoven fabric which is
imparted with a three-dimensional image or pattern, and apertures
essentially devoid of fiber, during the fabrication stage. The
nonwoven fabric exhibits a fibrous extension out of the plan of the
material, while apertures are present that have a pronounced
uniformity and a significant reduction in fibrous occlusion.
[0026] With reference to FIG. 1, therein is illustrated an
apparatus for practicing the present method for forming a nonwoven
fabric. The fabric is formed from a fibrous matrix, which typically
comprises staple length fibers. The fibrous matrix is preferably
carded and cross-lapped to form a precursor web, designated P. In a
current embodiment, the precursor web comprises a majority of
cross-lap fibers, that is, most of the fibers of the web have been
formed by cross-lapping a carded web so that the fibers are
oriented at an angle relative to the machine direction of the
resultant web.
[0027] FIG. 1 illustrates a hydroentangling apparatus for forming
nonwoven fabrics in accordance with the present invention. The
apparatus includes a foraminous-forming surface in the form of belt
10 upon which the precursor web P is positioned for pre-entangling
by entangling manifold 12. Pre-entangling of the precursor web,
prior to imaging and patterning, is subsequently effected by
movement of the web P sequentially over a drum 14 having a
foraminous forming surface, with entangling manifold 16 effecting
entanglement of the web. Further entanglement of the web is
effected on the foraminous forming surface of a drum 18 by
entanglement manifold 20, with the web subsequently passed over
successive foraminous drums 22, for successive entangling treatment
by entangling manifolds 24', 24'.
[0028] The entangling apparatus of FIG. 1 further includes an
imaging and patterning drum 24 comprising a three-dimensional image
transfer device for effecting imaging and patterning of the
now-entangled precursor web. The image transfer device includes a
moveable imaging surface which moves relative to a plurality of
entangling manifolds 26 which act in cooperation with
three-dimensional elements defined by the imaging surface of the
image transfer device to effect imaging and patterning of the
fabric being formed.
[0029] Hydroentanglement results in portions of the precursor web
being displaced from on top of the three-dimensional surface
elements of the imaging surface to form an imaged and patterned
nonwoven fabric. Enhanced surface fiber extension is desirably
achieved, thus providing improved cleaning properties for the
resultant fabric, while uniform a relatively unoccluded apertures
are obtained.
EXAMPLES
Example 1
[0030] Using a forming apparatus as illustrated in FIG. 1, a
nonwoven fabric was made in accordance with the teachings of U.S.
Pat. No. 5,098,764 by providing a precursor web comprising
polyester staple fibers and rayon staple fibers.
[0031] Prior to patterning and imaging of the precursor web, the
web was entangled by a series of entangling manifolds such as
diagrammatically illustrated in FIG. 1. FIG. 1 illustrates
disposition of precursor web P on a foraminous forming surface in
the form of belt 10, with the web acted upon by an entangling
manifold 12. The web then passes sequentially over a drum 14 having
a foraminous forming surface, for entangling by entangling manifold
16, with the web thereafter directed about the foraminous forming
surface of a drum 18 for entangling by entanglement manifold 20.
The web is thereafter passed over successive foraminous drums 22,
with successive entangling treatment by entangling manifolds 24',
24'.
[0032] The entangling apparatus of FIG. 1 further includes an
imaging and patterning drum 24 comprising a three-dimensional image
transfer device for effecting imaging and patterning of the
now-entangled precursor web. The entangling apparatus includes a
plurality of entangling manifolds 26, which act in cooperation with
the three-dimensional image transfer device of drum 24 to effect
patterning of the fabric.
[0033] The three-dimensional imaged nonwoven fabric was configured
with an image, as illustrated in FIG. 2, wherein drain openings in
the image transfer device are illustrated as white circular
regions, and surface asperities are illustrated as black
squares.
Example 2
[0034] An exemplary material was made in accordance with the
present invention wherein the same fibrous matrix as used in
Example 1, was imparted with a three-dimensional topography and
coinciding apertures, wherein the aperture-forming asperities of
the image transfer device further each included a Peripheral
recessed region, such as shown in phantom line in FIG. 2.
[0035] Without being held to a specific mode of operation, it is
believed that the circumferential recessed region allows for
hydraulic turbulents formed off of the aperture-forming asperity
during application of hydraulic to inter-entangle the fibrous
matrix displaced from the asperity. This inter-entanglement of the
displaced fibers imparts a durable integration of the fibers, and
thus restrains these same fibers from displacement into the newly
formed aperture in the resulting fabric.
[0036] Photometric analysis of Example 1 and Example 2 are provided
in FIGS. 5a/b and 6a/b, respectively. As can be seen in the
luminosity plots 6a and 6b, the material of the present invention
presents a more pronounced aperture versus the materials made
without specific control of the fibrous matrix on the periphery of
the aperture. Values for clarity of opening are determined in the
manner described in the U.S. Pat. No. 5,098,764, herein
incorporated by reference.
[0037] The luminosity plots show graphical projections which
represent the clearity of the apertures within the corresponding
fabrics. As shown in FIGS. 5a and 5b, the graphical projections
consist of shades of grey that start out dark at the base and
gradually lighten while tapering from the base of the projection so
as to form a pointed apex. The area of the projection at its apex
is less than 50% of the area at the base of the projection. The
tapering of the projections that occurs is due to fiber
interference within the aperture, indicating that only a minimal
portion of the aperture is completely devoid of fibers.
[0038] The luminosity plots of FIGS. 6a and 6b show the graphical
projections that correspond with the fabric of the present
invention. The graphical projections of FIGS. 6a and 6b also
consist of shades of grey that start out dark at the base and
gradually lighten toward the apex of the projections. It should be
noted that the projections demonstrate only minimal tapering from
the base to the apex. Further, the area of the projection at its
apex is greater than 50% of the area at the base of the projection.
The broader apex of the graphical projections in FIGS. 6a and 6b
are due the lack of fiber interference within the aperture,
indicating that the aperture has improved clearity.
[0039] From the foregoing, it will be observed that numerous
modifications and variations can be affected without departing from
the true spirit and scope of the novel concept of the present
invention. It is to be understood that no limitation with respect
to the specific embodiments illustrated herein is intended or
should be inferred. The disclosure is intended to cover, by the
appended claims, all such modifications as fall within the scope of
the claims.
* * * * *