U.S. patent application number 11/013299 was filed with the patent office on 2005-06-16 for physical and mechanical properties of fabrics by hydroentangling.
This patent application is currently assigned to North Carolina State University. Invention is credited to Pourdeyhimi, Behnam.
Application Number | 20050125908 11/013299 |
Document ID | / |
Family ID | 34699993 |
Filed Date | 2005-06-16 |
United States Patent
Application |
20050125908 |
Kind Code |
A1 |
Pourdeyhimi, Behnam |
June 16, 2005 |
Physical and mechanical properties of fabrics by
hydroentangling
Abstract
Methods for reducing the surface pilling tendency and improving
abrasion resistance of a pillable fabric are disclosed. The methods
include providing a pillable fabric including fibrils extending
from the surfaces thereof, supporting the fabric, and exposing the
fabric to a hydroentanglement process that imparts an energy in the
range of at least about 4000 to 5000 KJoules/Kg of fabric using
pressures of 200 bars or greater. The presence of fibrils on the
fabric surface are reduced to an amount wherein the pilling
production on the fabric is less than about 20% after 5,000 cycles
of abrasion on a Martindale device according to ASTM D4970 testing
standard and the fabric remaining mass is at least about 80% to 90%
after 50,000 cycles of abrasion on a Martindale device according to
ASTM D4966 testing standard.
Inventors: |
Pourdeyhimi, Behnam; (Cary,
NC) |
Correspondence
Address: |
JENKINS, WILSON & TAYLOR, P. A.
3100 TOWER BLVD
SUITE 1400
DURHAM
NC
27707
US
|
Assignee: |
North Carolina State
University
|
Family ID: |
34699993 |
Appl. No.: |
11/013299 |
Filed: |
December 15, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60529490 |
Dec 15, 2003 |
|
|
|
Current U.S.
Class: |
8/115.51 |
Current CPC
Class: |
D06C 29/00 20130101;
D04H 1/492 20130101 |
Class at
Publication: |
008/115.51 |
International
Class: |
D06M 010/00 |
Claims
What is claimed is:
1. A method for reducing the surface pilling tendency and improving
abrasion resistance of a pillable fabric, the method comprising the
steps of: (a) providing a pillable fabric having a top surface, a
bottom surface, and side edges and comprising yarns which intersect
at crossover points to define interstitial open areas in the
fabric, and the fabric further comprising fibrils extending from at
least one of the top and bottom surfaces thereof; (b) supporting
the fabric on a support member; (c) exposing at least one of the
surfaces to a hydroentanglement process to cause entanglement of
the fibrils into the interstitial open areas of the fabric, wherein
the hydroentanglement process includes imparting an energy in the
range of at least about 4000 to 5000 KJoules/Kg of fabric using
pressures of 200 bars or greater; and (d) reducing the presence of
the fibrils on the at least one fabric surface to an amount wherein
the pilling production on the fabric is less than about 20% after
5,000 cycles of abrasion on a Martindale device according to ASTM
D4970 testing standard and the fabric remaining mass is at least
about 80% to 90% after 50,000 cycles of abrasion on a Martindale
device according to ASTM D4966 testing standard.
2. The method of claim 1 wherein the fabric is a woven fabric.
3. The method of claim 1 wherein the fabric is a knitted
fabric.
4. The method of claim 3 further comprising the step of restraining
the side edges of the knitted fabric to prevent shrinkage during
the hydroentanglement process.
5. The method of claim 1 wherein the fabric yarns are selected from
the group consisting of cotton, polyester, nylon, and blends
thereof.
6. The method of claim 1 wherein the support member is selected
from the group consisting of a belt, a drum, and a belt/drum
combination.
7. The method of claim 6 wherein the support member includes a
pattern of closely spaced fluid pervious open areas to affect fluid
passage through the support member.
8. The method of claim 1 wherein both surfaces of the fabric are
exposed to the hydroentanglement process.
9. The method of claim 1 wherein the hydroentanglement process is
accomplished by the use of a hydroentanglement system comprising at
least one bank of one or more high pressure water jet
manifolds.
10. The method of claim 9 wherein the hydroentanglement system
comprises two banks of high pressure water jet manifolds that apply
high pressure water jets to the fabric top and bottom surfaces.
11. The method of claim 10 wherein the hydroentanglement system
comprises one bank of three manifolds that apply high pressure
water jets to the fabric top surface and one bank of two manifolds
that apply high pressure water jets to the fabric bottom
surface.
12. The method of claim 9 wherein the water pressure of the one or
more manifolds is between 10 bars and 1000 bars.
13. The method of claim 12 wherein each of the one or more
manifolds further comprises approximately 1600 to 2000 fluid jet
orifices per meter, wherein each orifice has a diameter of
approximately 80 to 300 microns.
14. A fabric produced according to the method of claim 1.
15. A method for reducing the surface pilling tendency and
improving abrasion resistance of a pillable cotton knitted fabric,
the method comprising the steps of: (a) providing a pillable cotton
knitted fabric having a top surface, a bottom surface, and side
edges and comprising yarns which intersect at crossover points to
define interstitial open areas in the fabric, and the fabric
further comprising fibrils extending from at least one of the top
and bottom surface thereof; (b) supporting the fabric on a support
member; (c) restraining the side edges of the knitted fabric; (d)
exposing at least one of the surfaces to a hydroentanglement
process system comprising at least one bank of one or more high
pressure water jet manifolds to cause entanglement of the fibrils
into the interstitial open areas of the fabric, wherein the
hydroentanglement process system imparts an energy in the range of
at least about 4000 to 5000 KJoules/Kg of fabric using pressures of
200 bars or greater; and (e) reducing the presence of the fibrils
on the at least one fabric surface to an amount wherein the pilling
production on the fabric is less than about 20% after 5,000 cycles
of abrasion on a Martindale device according to ASTM D4970 testing
standard and the fabric remaining mass is at least about 80% to 90%
after 50,000 cycles of abrasion on a Martindale device according to
ASTM D4966 testing standard.
16. The method of claim 15 wherein the support member is selected
from the group consisting of a belt, a drum, and a belt/drum
combination.
17. The method of claim 16 wherein the support member includes a
pattern of closely spaced fluid pervious open areas to affect fluid
passage through the support member.
18. The method of claim 15 wherein both surfaces of the fabric are
exposed to the hydroentanglement process system.
19. The method of claim 15 wherein the hydroentanglement system
comprises two banks of high pressure water jet manifolds that apply
high pressure water jets to the fabric top and bottom surfaces.
20. The method of claim 19 wherein the hydroentanglement system
comprises one bank of three manifolds that apply high pressure
water jets to the fabric top surface and one bank of two manifolds
that apply high pressure water jets to the fabric bottom
surface.
21. The method of claim 15 wherein the water pressure of the one or
more manifolds is between 10 bars and 1000 bars.
22. The method of claim 22 wherein each of the one or more
manifolds further comprises approximately 1600 to 2000 fluid jet
orifices per meter, wherein each orifice has a diameter of
approximately 80 to 300 microns.
23. A fabric produced according to the method of claim 15.
24. A pill and abrasion resistant fabric comprising: (a) a top
surface, a bottom surface, and side edges; (b) multiple yarns
intersecting at crossover points to define interstitial open areas
in the fabric; (c) fibrils extending from at least one of the top
and bottom surfaces which have been entangled into the interstitial
open areas of the fabric by exposure of at least one of the top and
bottom surfaces to a hydroentanglement process including imparting
an energy in the range of at least about 4000 to 5000 KJoules/Kg of
fabric using pressures of 200 bars or greater; and (d) wherein the
pill and abrasion resistant fabric possesses a reduced pill
production potential of less than about 20% after 5,000 cycles of
abrasion on a Martindale device according to ASTM D4970 testing
standard and possesses an increased abrasion resistance potential
wherein the fabric remaining mass is at least about 80% to 90%
after 50,000 cycles of abrasion on a Martindale device according to
ASTM D4966 testing standard.
25. The fabric of claim 24 wherein the fabric is a woven
fabric.
26. The fabric of claim 24 wherein the fabric is a knitted
fabric.
27. The fabric of claim 24 wherein the fabric yarns are selected
from the group consisting of cotton, polyester, nylon, and blends
thereof.
28. The fabric of claim 24 wherein both surfaces of the fabric have
been exposed to the hydroentanglement process.
29. A pill and abrasion resistant cotton knitted fabric comprising:
(a) a top surface, a bottom surface, and side edges; (b) multiple
yarns intersecting at crossover points to define interstitial open
areas in the fabric; (c) fibrils extending from at least one of the
top and bottom surfaces which have been entangled into the
interstitial open areas of the fabric by exposure of at least one
of the top and bottom surfaces to a hydroentanglement process
including imparting an energy in the range of at least about 4000
to 5000 KJoules/Kg of fabric using pressures of 200 bars or
greater; and (d) wherein the pill and abrasion resistant fabric
possesses a reduced pill production potential of less than about
20% after 5,000 cycles of abrasion on a Martindale device according
to ASTM D4970 testing standard and possesses an increased abrasion
resistance potential wherein the fabric remaining mass is at least
about 80% to 90% after 50,000 cycles of abrasion on a Martindale
device according to ASTM D4966 testing standard.
30. The fabric of claim 29 wherein both surfaces of the cotton
knitted fabric have been exposed to the hydroentanglement process.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 60/529,490, filed Dec. 15, 2003; the
disclosure of which is incorporated herein by reference in its
entirety.
TECHNICAL FIELD
[0002] The subject matter disclosed herein relates generally to
fabrics having antipilling properties. More particularly, the
present subject matter relates to methods for reducing the pilling
tendency and improving abrasion resistance of a pillable fabric
through the use of a hydroentanglement process.
BACKGROUND ART
[0003] Cotton and cotton blend woven and knitted fabrics have a
great tendency to be subjected to pilling or generate so-called
"pills". Many other staple fibers and blends thereof when formed
into woven and knitted fabrics also have a tendency to pill. Pills
are small bunches or balls of interlaced fluff caused by small
bundles of entangled fibers clinging to the cloth surface by one or
more surface fibrils. Pilling is typically preceded by fuzz
formation and when the material is subject to physical stimulation
such as friction, the fuzz or fluff clumps together and is gathered
by the fibrils. This undesirable pilling effect occurs with the
lapse of time and wear and the tendency to pill generally lowers
the commercial value of the fabrics.
[0004] Given the undesirable nature of a fabric that is subject to
pilling, several industrial means have previously been employed in
order to prevent such generation of pills. For example, U.S. Pat.
No. 3,975,486 to Sekiguchi et al. is directed to a process for
producing an antipilling acrylic fiber wherein the steps of
coagulation, stretching and relaxing heat treatment are conducted
under particular conditions. Likewise, U.S. Pat. No. 4,205,037 to
Fujimatsu is directed to acrylic synthetic fibers highly resistant
to pilling and having good dyeability produced by specifying the
composition of the acrylic polymer, the condition of the primary
stretching step, the internal water content of the water-swollen
gel fibers, and the conditions of the steps of the
drying-compacting, secondary stretching and relaxing heat
treatment. Additionally, U.S. Pat. No. 6,051,034 to Caldwell is
directed to a method for reducing pilling of cellulosic towels
wherein a composition comprising an acidic agent, and optionally a
fabric softener, is applied to a pillable cellulosic towel,
preferably to the face yarns of the towel. The towel is then heated
for a time and under conditions sufficient to effect a controlled
degradation of the cellulosic fibers, thereby reducing pilling.
[0005] While these prior art antipilling techniques have included
various methods of reducing the pilling tendency of a fabric using
chemical or other process modifications, the need exists for a
simpler and more effective finishing method for producing fabrics
that have a lower tendency to pill as well as having improved
abrasion resistance.
[0006] As is well known to those skilled in the art,
hydroentanglement or "spun lacing" is a process used for
mechanically bonding a web of loose fibers to form fabrics directly
from fibers. This class of fabric typically belongs to the
nonwovens family of engineered fabrics. In conventional
hydroentangling processes, webs of nonwoven fibers are treated with
high pressure fluid jets while supported on apertured patterning
screens. Typically, the patterning screen is provided on a drum or
continuous planar conveyor. The underlying mechanism in
hydroentanglement is the subjecting of the fibers to a non-uniform
pressure field created by successive banks of fine, closely spaced,
high-velocity water jets. The impact of the water jets with the
fibers, while they are in contact with their neighboring fibers,
displaces and rotates the fibers with respect to their neighbors
and entangles these fibers with the neighboring fibers. During
these relative displacements, some of the fibers twist around
others and/or interlock with the neighboring fibers to form a
strong structure due to fiber-to-fiber frictional forces. The final
outcome is a highly compressed and uniform fabric composed of
entangled fibers that is characterized by relatively high strength,
flexibility, and conformability.
[0007] In the past, various efforts have been directed to improving
the dimensional stability and physical properties of woven and
knitted fabrics through the finishing step of hydroentanglement. In
such applications, warp and filling fibers in fabrics are
hydroentangled at crossover points to effect enhancement in fabric
cover.
[0008] For example, U.S. Pat. No. 4,695,500 to Dyer et al. is
directed to a loosely constructed knit or woven fabric that is
dimensionally stabilized by causing staple length textile fibers to
be entangled about the intersections of the yarns comprising the
fabric. The stabilized fabric is formed by covering one or both
sides of the loosely constructed base fabric with a light web of
the staple length fibers, and subjecting the composite material to
hydraulic entanglement while supported on a porous forming belt
configured to direct and concentrate the staple length fibers at
the intersections of the yarns comprising the base fabric.
[0009] U.S. Pat. No. 5,136,761 to Sternlieb et al. is directed to
an apparatus and method for enhancement of woven and knit fabrics
through the use of dynamic fluids which entangle and bloom fabric
yarns. The process includes a two stage enhancement process wherein
top and bottoms sides of the fabric are respectively supported and
impacted with a fluid curtain included high pressure jet streams.
The controlled process energies and use of the support members
having open areas which are aligned in offset relation to the
process line produces fabrics having a uniformed finish and
improved characteristics including edge fray, drape, stability,
abrasion resistance, fabric weight and thickness.
[0010] U.S. Pat. No. 5,761,778 to Fleissner is directed to a method
for hydrodynamic entanglement or needling, preferably for
binder-free compaction, of fibers of a fiber web, especially a
nonwoven fiber web, composed of natural or synthetic fibers of any
type, wherein the fibers of the fiber web are entangled and
compacted with one another by a plurality of water streams or jets
applied at high pressure, with a large number of the water streams
or jets striking the fiber web not only in succession but also
several times on alternate sides of the web for optimum twisting of
the fibers on the top and bottom on the fiber web.
[0011] Finally, U.S. Pat. No. 6,557,223 to Greenway et al. is
directed to improvements in hydroenhancement efficiency obtained by
operating a manifold in relative movement to fabric transported
under the manifold so as to deliver a low energy to the fabric per
pass in multiple passes on the fabric. This process results in
greater enhancement efficiency and reduction in wasted energy, and
also improves fabric coverage and reduces fabric shrinkage.
[0012] While these prior art hydroentanglement finishing processes
have been directed to improving dimensional stability and physical
properties such as edge fray and drape and abrasion resistance,
there remains a need to better reduce the pilling tendency and
better improve abrasion resistance of a pillable fabric utilizing a
physical finishing method that can be employed based upon specific
process parameters for generation of an antipilling fabric.
SUMMARY
[0013] In accordance with one embodiment of the present subject
matter, a method for reducing the surface pilling tendency and also
improving abrasion resistance of a pillable fabric is
disclosed.
[0014] The method includes the step of providing a pillable fabric,
the fabric having a top surface, a bottom surface, and side edges
and comprising yarns which intersect at crossover points to define
interstitial open areas in the fabric and further comprising
fibrils extending from at least one of the top and bottom surfaces
thereof. The fabric may comprise a woven fabric or a knitted fabric
and the fabric yarns may include cotton, polyester, nylon, or
blends thereof. The fabric is supported on a support member wherein
the support member may comprise a belt, a drum, or a belt/drum
combination and may include a pattern of closely spaced fluid
pervious open areas to affect fluid passage therethrough. At least
one of the surfaces is exposed to a hydroentanglement process to
cause entanglement of the fibrils into the interstitial open areas
of the fabric. The hydroentanglement process preferably includes
imparting an energy in the range of at least about 4000 to 5000
KJoules/Kg of fabric using pressures of 200 bars or greater and
includes the use of banks of one or more high pressure water jet
manifolds that apply high pressure water jets to the fabric top
and/or bottom surfaces.
[0015] The method further includes reducing the presence of the
fibrils on the at least one fabric surface to an amount wherein the
pilling production on the fabric is less than about 20% after 5,000
cycles of abrasion on a Martindale device according to ASTM D4970
testing standard. The fibrils are also reduced to an amount wherein
the remaining mass of the fabric is at least about 80% to 90% after
50,000 cycles of abrasion on a Martindale device according to ASTM
D4966 testing standard.
[0016] It is therefore an object of the present subject matter to
provide a method for reducing the pilling tendency and improving
abrasion resistance of a pillable fabric utilizing a finishing
hydrointanglement process that results in the removal or
entanglement of pilling-causing fibrils such that the tendency of
the fabric to pill is greatly reduced, as gauged by pilling
production calculated or remaining mass calculated after a set
number of abrasion test cycles.
[0017] An object of the present subject matter having been stated
hereinabove, and which is addressed in whole or in part by the
present subject matter, other objects will become evident as the
description proceeds when taken in connection with the accompanying
drawings as best described hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIGS. 1A and 1B are plan and side views, respectively, of a
typical woven product treated in accordance with the process of the
present subject matter;
[0019] FIGS. 2A-2C are cross-sectional, top plan, and bottom plan
views, respectively, of a typical hydroentangling nozzle provided
in accordance with the present subject matter;
[0020] FIGS. 3A and 3B are schematic drawings of typical
hydroentangling configurations in accordance with the present
subject matter;
[0021] FIG. 4 is a line graph depicting the effect of
hydroentangling and washing on fabric sample thickness;
[0022] FIGS. 5A-5F; 6A-6F; and 7A-7F are enlarged photographic
surface views of control fabric samples and samples treated in
accordance with the present subject matter;
[0023] FIGS. 8A-8C are line graphs depicting weight loss of fabric
samples in relation to the number of abrasion cycles conducted;
FIGS. 9A-9H; 10A-10H; 11A-11F; and 12A-12H are enlarged
photographic surface views of control fabric samples and samples
treated in accordance with the present subject matter after
undergoing abrasion testing;
[0024] FIGS. 13A and 13B are line graphs depicting pilling
production of fabric samples in relation to the number of abrasion
cycles conducted;
[0025] FIGS. 14A and 14B are enlarged photographic surface views
showing pilling production of a control fabric sample and a sample
treated in accordance with the present subject matter,
respectively, after undergoing abrasion testing; and
[0026] FIGS. 15A-15H; 16A-16F; and 17A-17D are enlarged
photographic surface views of control fabric samples and varying
fabric composition samples treated in accordance with the present
subject matter.
DETAILED DESCRIPTION
[0027] The subject matter disclosed herein relates to methods for
reducing the pilling tendency and improving abrasion resistance of
a pillable fabric through the use of a hydroentanglement process.
Hydroentanglement finishing at specified process parameters results
in the complete removal or entanglement of surface yarn fibrils
into the body of the fabric thereby improving the fabric strength
while making the surface more smooth. Since the fibrils are no
longer available on the fabric surface, they cannot entangle other
fibers to form fluff balls or pills. The present subject matter is
directed to the use of a high energy hydroentanglement process that
has lead to significantly improved physical and mechanical
properties of fabrics.
[0028] Referring to FIGS. 1A and 1B, a typical pillable fabric 10
treated by the process of the present subject matter is shown by
example as a woven fabric, although it is also envisioned that
additional fabrics such as knitted fabrics may be treated in
accordance with the present subject matter. Fabric 10 has a top
surface TS, a bottom surface BS, and side edges E and comprises an
open structure comprising warp yarns 12 extending in the machine
direction and fill yarns 14 crossing at right angles to the warp
yarns. The yarns are not secured at the intersections and
consequently are easily displaced by external forces. Fibrils 16
are hook-like projections extending from yarns 12, 14 which extend
away from top and bottom surfaces TS, BS of fabric 10 and
contribute to the pilling properties of the fabric.
[0029] Yarns 12, 14 of fabric 10 may be selected from cotton,
polyester, nylon, and other yarn compositions known to those of
skill in the art. Additionally, blends of various fiber types may
be used to form the fabric yarns.
[0030] Referring now to FIGS. 2A-2C, a typical hydroentangling
nozzle assembly 20 provided in accordance with one aspect of the
present subject matter is shown in cross-section, top plan view,
and bottom plan view, respectively. Hydroentangling nozzles are
traditionally made up of two sections: a cylindrical section 22
(capillary part) with a typical diameter of about 120 microns,
connected to a slim cone 24 with a side angle extending
approximately 18 degrees outwardly from the side of cylindrical
section 22. Hydroentangling water jets are issued from thin-plate
strips 26 having 1600-2000 orifices per meter and produce operating
pressures ranging from 10 bars to over 1000 bars. FIG. 2B depicts a
top view of strip 26 wherein cylindrical section 22 of the orifice
is shown, and FIG. 2C depicts a bottom view of strip 26 wherein
cone 24 of the orifice is shown.
[0031] The amount of energy imparted to the fabric during
hydroentanglement can be very significant. Energy calculation is
based on Bernoulli equation that ignores viscous losses throughout
the system. Having the hydroentangling manifold's pressure as
P.sub.1, the water jet velocity can be calculated as:
V.sub.1={square root}{square root over (2P.sub.1/.rho.)}
[0032] Where .rho.=998.2 kg/m.sup.3 (the density of water at room
temperature), P.sub.1 is the pressure in Pa, and V.sub.1 is in m/s.
(Note that 1 bar is equal to 10.sup.5 Pa.)
[0033] Rate of energy transferred by the water jet is calculated as
follows: 1 E = 8 d 2 C d V 3
[0034] Where d is the diameter of the orifice capillary section in
millimeters (assumed in a Hyrdocalculator to be 0.127 mm), C.sub.d
is the discharge coefficient, and E is energy rate in J/s.
[0035] Specific energy is calculated based on the following
formula: 2 SE [ J kg fabric ] = E M
[0036] Where M is the mass flow rate of the fabric in Kg/s and is
calculated as follows
[0037]
M=Samplewidth[m].times.Basisweight[kg/m.sup.2].times.Beltspeed[m/s]
[0038] Therefore, SE will be obtained in Joules per kg of
fabric.
[0039] With reference to FIGS. 3A and 3B, pilling tendency
reduction and abrasion resistance enhancement of fabric 10 is
accomplished by entanglement and intertwining of fibrils on the
surfaces of fabric 10 by hydroentangling finishing systems 30 and
40 wherein fabric 10 is supported by support members such as a drum
32 or an endless belt 34 or a combination thereof and impacted with
a curtain of water jets under controlled process energies. Support
members 32, 34 may include a pattern of closely spaced fluid
pervious open areas to affect fluid passage therethrough and are
designed to process fabric 10 through the system at a controlled
rate.
[0040] Since knitted fabric has a tendency to shrink during
exposure to water processes, it is further envisioned by the
present subject matter that the side edges of the knitted fabric
may be restrained during the hydroentanglement process in order to
reduce the potential for shrinkage during processing (not shown).
The restraining of the fabric edges may be accomplished by clamps
along the conveyor system or by other mechanisms known to those of
skill in the art.
[0041] Hydroentanglement system 30 further includes preferably two
banks 36A, 36B of one or more high pressure water jet manifolds 38
oriented in a perpendicular direction relative to movement of
fabric 10. Manifolds 38 may typically be spaced several inches
apart and include a plurality of closely aligned and spaced nozzles
20. Hydroentanglement system 40 also preferably includes two banks
46A, 46B of one or more high pressure water jet manifolds 38. It is
envisioned that banks 36A, 36B (FIG. 3A) with manifolds 38 may be
arranged along support members 32 of system 30 in order to impart
pilling reduction enhancement to both surfaces TS, BS of fabric 10
with one pass direction. Banks 46A, 46B with manifolds 38 may be
arranged along support members 32, 34 of system 40 (FIG. 3B) to
impart the same effects. For example, as shown in FIGS. 3A and 3B,
hydroentanglement systems 30 and 40 may comprise one bank 36B, 46B
of three manifolds 38 that impart pilling reduction enhancement to
fabric top surface TS and another bank 36A, 46A of two manifolds 38
that impart pilling reduction enhancement to fabric bottom surface
BS.
[0042] Each manifold 38 may comprise approximately 1600 to 2000
fluid nozzle orifices 20 per meter, wherein each nozzle 20 has an
orifice diameter of approximately 80-300 microns, preferable 120
microns. Water pressure in each manifold 36 may be between 10 bars
and 1000 bars depending on the amount of nozzle orifices 20 present
and the size of the particular orifices. For optimum results in
pilling reduction and abrasion resistance, it has been discovered
that hydroentanglement systems 30 and 40 should each impart an
energy in the range of at least about 4000 to 5000 KJoules/Kg of
fabric using pressures of 200 bars or greater during processing of
fabric 10.
EXAMPLES
Test Methods and Standards Reporting
[0043] Experiments were conducted on sample fabrics using
hydroentanglement system 40 (see FIG. 3B) in order to determine the
effect on mechanical properties (pilling, abrasion, etc.) and hand
improvement of a finished textile utilizing the finishing concept
of the present subject matter. Different settings of the
hydroentanglement process were tested for physical properties with
the results presented below.
[0044] The samples exposed to hydroentangling were subjected to the
hydroentangling process as described hereinabove. The
hydroentangling process system comprised one bank of three (3)
water jet manifolds that enhanced the top surface (face) of the
fabric and one bank of two (2) water jet manifolds that enhanced
the bottom surface (back) of the fabric. The manifold pressures of
the systems were as shown in Table 1.
1TABLE 1 Water Jet Pressures Manifold Position Beam Pressure (bar)
Manifold 1 - Face pre-wet 60 Manifold 2 - Face entangling 150
Manifold 3 - Face entangling 200 Manifold 4 - Back entangling 150
Manifold 5 - Back entangling 200
[0045] The determination of the resistance to the formation of
pills, abrasion resistance, and other related surface changes on
textile fabrics is governed by testing standards ASTM D4966 for
abrasion resistance and ASTM D4970 for pilling. The testing
procedures utilize the Martindale tester and is generally
applicable to all types of fabrics.
[0046] In general, under the ASTM D4966 test, abrasion resistance
is measured by subjecting the specimen to rubbing motion in the
form of a geometric figure under known conditions of pressure and
abrasive action. Resistance to abrasion is evaluated by the
determination of mass loss as the difference between the masses
before and after abrasion (expressed as a percentage of the before
abrasion mass) and an end point when a hole appears in the fabric
sample.
[0047] In general, under the ASTM D4970 test, resistance to pill
formation testing involves mounting the fabric on the Martindale
tester wherein the face of the test specimen is rubbed against the
face of the same mounted fabric in a geometric pattern. The test
specimen is compared with visual standards of actual fabrics or
photographs of fabrics showing a range of pilling resistance in
order to gauge the degree of fabric pilling or surface appearance
change. The observed resistance to pilling is reported using an
arbitrary scale from 5 (no pilling) to 1 (very severe pilling) as
described in more detail hereinbelow.
Example I
The Effect of the Tightness Factor
[0048] Referring to FIGS. 5-14, experiments were first run on a
single type of fiber composition at various fiber tightness
factors. Due to its vast usage in the garment industry, the sample
textile fabric chosen consisted of a single jersey structure
knitted on a circular knitting machine (gauge 18) incorporating
yarns of 100% cotton (Ne 18/1 cp ringspun; 35 Tex). Three tightness
factor fabrics 15 were used and various samples were either washed
or not washed and were broken down into groups including no
hydroentangling passes, one hydroentangling pass, and two
hydroentangling passes. The samples were identified as shown in
Table 2.
2TABLE 2 Descriptions of Sample Set Surface # of Sample Tightness
Mass Thickness Hydroentangling ID factor (g/m.sup.2) (mm) Passes
Wash/Dry C16.00 16.00 183 0.597 0 No NH C16.00 16.00 183 0.597 1 No
1P C16.00 16.00 183 0.597 1 Yes 1P W C16.67 16.67 188 0.610 0 No NH
C16.67 16.67 188 0.610 1 No 1P C16.67 16.67 188 0.610 1 Yes 1P W
C17.56 17.56 199 0.648 0 No NH C17.56 17.56 199 0.648 1 No 1P
C17.56 17.56 199 0.648 2 No 2P C17.56 17.56 199 0.648 1 Yes 1P
W
[0049] Effect on Thickness
[0050] FIG. 4 graphically depicts the effect of hydroentangling and
washing on the thickness of the various samples. The
non-hydroentangled/non-washed samples had the greatest sample
thicknesses ranging from approximately 0.6 mm to 0.65 mm, while the
hydroentangled/non-washed samples had the lowest sample thicknesses
ranging from approximately 0.56 mm to 0.58 mm. Washing of the
hydroentangled samples generally increased sample thickness
slightly.
[0051] Effect on Surface Properties
[0052] As shown pictorially in FIGS. 5-7, in all three sets of
fabrics, more loose surface fibers (fibrils) are found in the
non-hydroentangled fabrics, as the structure is more loose in
general. Surface fibrils in the hydroentangled fabrics are more
compact and are entangled into the interstices between the yarns or
15 cut from the fabric surface altogether, thus allowing the fabric
structures to be more apparent in the hydroentangled fabrics due to
the absence of multiple loose surface fibers.
[0053] FIGS. 5A, 5 C, and 5 E show the 16 tightness factor
non-hydroentangled fabric at magnifications of 35.times.,
100.times., and 300.times., respectively. FIGS. 5B, 5D, and 5F show
the 16 tightness factor one-pass hydroentangled fabric at
magnifications of 35.times., 100.times., and 300.times.,
respectively.
[0054] FIGS. 6A, 6C, and 6E show the 16.67 tightness factor
non-hydroentangled fabric at magnifications of 35.times.,
100.times., and 300.times., respectively. FIGS. 6B, 6D, and 6F show
the 16.67 tightness factor one-pass hydroentangled fabric at
magnifications of 35.times., 100.times., and 300.times.,
respectively.
[0055] FIGS. 7A, 7C, and 7E show the 17.56 tightness factor
non-hydroentangled fabric at magnifications of 35.times.,
100.times., and 300.times., respectively. FIGS. 7B, 7D, and 7F show
the 17.56 tightness factor one-pass hydroentangled fabric at
magnifications of 35.times., 100.times., and 300.times.,
respectively.
[0056] Effect on Abrasion Resistance (Mass Loss)
[0057] With reference for FIGS. 8A-8C, three fabric samples of
three (3) different tightness factors showed increases in abrasion
resistance when subjected to hydroentanglement, indicated by the
significantly lower weight reduction (i.e., more remaining mass)
after exposure to up to 70,000 cycles on the Martindale tester.
Higher abrasion resistance in hydroentangled samples vs.
non-hydroentangled samples was shown by reduced mass loss and
longer cycles needed to make the first hole in the fabrics.
[0058] Specifically, FIG. 8A depicts abrasion testing on fabric
samples with a 16 tightness factor. The non-hydroentangled sample
(NH) showed a steep decline in remaining mass reaching around 75%
remaining mass when a hole developed in the fabric after
approximately 35,000 cycles. The one-pass non-washed hydroentangled
sample (1P) showed a remaining mass of approximately 87% when a
hole developed in the fabric after approximately 50,000 cycles. The
one-pass washed hydroentangled sample (1PW) showed a gradual
decline in remaining mass reaching around 82% when a hole developed
in the fabric after approximately 70,000 cycles.
[0059] FIG. 8B depicts abrasion testing on fabric samples with a
16.67 tightness factor. The non-hydroentangled sample (NH) showed a
steep decline in remaining mass reaching around 73% remaining mass
when a hole developed in the fabric after approximately 36,000
cycles. The one-pass non-washed hydroentangled sample (1P) showed a
remaining mass of approximately 91% when a hole developed in the
fabric after approximately 50,000 cycles. The one-pass washed
hydroentangled sample (1PW) showed a gradual decline in remaining
mass reaching around 83% when a hole developed in the fabric after
approximately 52,000 cycles.
[0060] FIG. 8C depicts abrasion testing on fabric samples with a
17.56 tightness factor. The non-hydroentangled sample (NH) showed a
steep decline in remaining mass reaching around 78% remaining mass
when a hole developed in the fabric after approximately 36,000
cycles. The one-pass non-washed hydroentangled sample (1P) showed a
remaining mass of approximately 83% when a hole developed in the
fabric after approximately 52,000 cycles. The two-pass non-washed
hydroentangled sample (2P) showed a remaining mass of approximately
83% when a hole developed in the fabric after approximately 48,000
cycles. As shown pictorially in FIGS. 9-12, representing two (2)
types of tightness factor fabrics being hydroentangled and
non-hydroentangled, as the abrasion cycles increased, fibers in
both series of fabrics were cut and fibrillated. However, while the
cut ends of the fibers in the non-hydroentangled fabrics are
protruded from the surface and can lead to generation of pilling,
the cut ends of the fibers in the hydroentangled fabrics remained
entangled into the fabric interstices so as to not contribute to
pilling tendency.
[0061] Specifically, FIGS. 9A-9H show the fabric surface of the 16
tightness factor non-hydroentangled fabric at magnifications of
35.times. and 100.times. at abrasion cycles of 0, 2000, 20000, and
35000.
[0062] FIGS. 10A-10H show the fabric surface of the 16 tightness
factor one-pass hydroentangled fabric at magnifications of
35.times. and 100.times. at abrasion cycles of 0, 2000, 20000, and
35000.
[0063] FIGS. 11A-11F show the fabric surface of the 17.56 tightness
factor non-hydroentangled fabric at magnifications of 35.times. and
100.times. at abrasion cycles of 0, 20000, and 35000.
[0064] FIGS. 12A-12H show the fabric surface of the 17.56 tightness
factor one-pass hydroentangled fabric at magnifications of
35.times. and 100.times. at abrasion cycles of 0, 2000, 30000, and
60000.
[0065] The markedly improved abrasion resistance of fabric samples
exposed to the hydroentangling process of the present invention can
be attributed to the entanglement or removal of the surface
fibrils. This effect leads to a smoother fabric surface and a
reduction in mass loss of the fabric during abrasion testing.
[0066] Effect on Pilling
[0067] Tests were conducted to determine the resistance of the
fabric samples to form pills on the fabric surface. The Martindale
tester was used to run through approximately 6000 cycles, wherein
the samples were intermittingly inspected and a standard pilling
rating was assigned to the samples according to the rating scale
shown in Table 3.
3TABLE 3 Pilling Rating Scale Rating Surface Evaluation 5 No
pilling 4 Slight pilling 3 Moderate pilling 2 Severe pilling 1 Very
severe pilling
[0068] With reference to FIGS. 13A and 13B, the pilling tendency of
the fabrics (16 tightness factor in FIG. 13A and 17.56 tightness
factor in FIG. 13B) were greatly reduced after hydroentanglement,
and even more so after washing and/or multiple passes through the
hydroentanglement process. The non-hydroentangled fabrics samples
(NH) showed very severe pilling after only approximately 150
cycles, while the hydroentangled fabrics (1P) displayed only slight
pilling even after 5000 cycles. The two-pass (2P) hydroentanglement
fabric sample (see FIG. 13B) showed no pilling until approximately
2000 cycles, when it began showing slight pilling.
[0069] FIGS. 14A and 14B pictorially display the pilling effect
after 5000 cycles on the Martindale device. FIG. 14A shows a cotton
knitted non-hydroentangled fabric sample after 5000 cycles. The
sample displayed very significant pilling (see also FIGS. 13A and
13B), due to the presence of surface fibrils. FIG. 14B shows a
cotton knitted hydroentangled fabric sample after 5000 cycles. The
sample displayed only slight pilling, hardly noticeable to the
viewer (see also FIGS. 13A and 13B).
[0070] As shown in FIGS. 13A, 13B and 14A, 14B, the pilling
behavior is strongly improved in fabric samples exposed to the
hydroentangling process of the present subject matter. Similar to
the markedly improved abrasion resistance, the pilling resistance
of the hydroentangled fabrics can be attributed to the specific
energy ranges of the present subject matter which cause a lack of
fibrils at the surface of the fabric either through entanglement of
the fibrils into the fabric interstices or perhaps removal of the
fibrils altogether. The smooth, fibril-less fabric surface results
in a fabric which has great abrasion resistance and a tendency not
to produce pills.
Example II
The Effect of Fiber Composition and Hydroentangling Parameters
[0071] Referring now to FIGS. 15-17, experiments were additionally
run on fabrics of various compositions and at varying
hydroentangling processing parameters. The textile fabric structure
comprised a single jersey construction with a 17.5 tightness
factor. The fabric compositions were formed as shown in Table 4 and
the samples and hydroentangling parameters (for those samples that
were hydroentangled) were identified as shown in Table 5.
4TABLE 4 Fabric Compositions Fiber Tightness factor Surface
Mass(g/m.sup.2) 100% cotton 17.5 229 50/50 Cotton/polyester 17.5
216 100% Polyester 17.5 199
[0072]
5TABLE 5 Descriptions of Sample Set and Hydroentangling Parameters
Belt Number Sample Pressure Pressure Pressure Pressure Pressure
Belt type speed of ID #1(bar) #2(bar) #3(bar) #4(bar) #5(bar)
Mesh/inch (m/min) Passes Fiber 1a 60 150 200 150 200 100 10 1
Cotton 1b 60 150 200 150 200 100 10 2 Cotton 1c 60 150 200 150 200
100 10 3 Cotton 2a 60 150 200 150 200 100 10 1 Co/Poly 3a 60 150
200 150 200 100 10 1 Polyester 4a 60 150 200 150 200 100 50 1
Cotton
[0073] Effect on 100% Cotton Fabrics
[0074] FIGS. 15A-15H pictorially display the surface structure of a
variety of the 100% cotton jersey fabric samples.
[0075] Specifically, FIGS. 15A and 15B show the surface image of a
non-washed, non-hydroentangled 100% cotton jersey fabric at
35.times. and 100.times. magnification, respectively, and FIGS. 15C
and 15D show the surface image of a washed, non-hydroentangled 100%
cotton jersey fabric at 35.times. and 100.times. magnification,
respectively. While the washed sample showed some fibrillation of
the fibers, neither of these non-hydroentangled fabric samples
showed substantial changes in the loose surface fibers as the
structure in general remained in a loose state.
[0076] FIGS. 15E and 15F show the surface image of a non-washed,
one-pass hydroentangled 100% cotton jersey fabric (sample 1a) at
35.times. and 100.times. magnification, respectively, and FIGS. 15G
and 15H show the surface image of a non-washed, two-pass
hydroentangled 100% cotton jersey fabric (sample 1b) at 35.times.
and 100.times. magnification, respectively. Each of these samples
showed extensive fibrillation of the cotton fibers and entanglement
of the surface fibers into the fabric interstice structure or
removal of the surface fibers altogether. The two-pass
hydroentangled fabric sample showed even more fibrillation of the
fibers over the one-pass hydroentangled sample, along with
additional flattening of the structure.
[0077] Effect on 50/50 Cotton/Polyester Fabrics
[0078] FIGS. 16A-16F pictorially display the surface structure of a
variety of the 50/50 cotton/polyester jersey fabric samples.
[0079] Specifically, FIGS. 16A and 16B show the surface image of a
washed, non-hydroentangled 50/50 cotton/polyester jersey fabric at
35.times. and 100.times. magnification, respectively. While some
fibers were fibrillated, the fabric sample showed no substantial
changes in the loose surface fibers.
[0080] FIGS. 16C and 16D show the surface image of a non-washed,
one-pass hydroentangled 50/50 cotton/polyester jersey fabric
(sample 2a, non-washed) at 35.times. and 100.times. magnification,
respectively, and FIGS. 16E and 16F show the surface image of a
washed, one-pass hydroentangled 50/50 cotton/polyester jersey
fabric (sample 2a, washed) at 35.times. and 100.times.
magnification, respectively. Each of these samples showed extensive
fibrillation of the cotton fibers and entanglement of the surface
fibers into the fabric interstice structure or removal of the
surface fibers altogether.
[0081] Effect on 100% Polyester Fabrics
[0082] FIGS. 17A-17D pictorially display the surface structure of a
variety of the 100% polyester jersey fabric samples.
[0083] Specifically, FIGS. 17A and 17B show the surface image of a
washed, non-hydroentangled 100% polyester jersey fabric at
35.times. and 100.times. magnification, respectively. The fabric
sample showed no substantial changes in the loose surface
fibers.
[0084] FIGS. 17C and 17D show the surface image of a washed,
one-pass hydroentangled 100% polyester jersey fabric (sample 3a,
washed) at 35.times. and 100.times. magnification, respectively.
The sample showed extensive entanglement of the surface fibers into
the fabric interstice structure or removal of the surface fibers
altogether.
[0085] The present subject matter reflects a use of specific ranges
of hydroentanglement energies to produce a fabric containing
unexpectedly and surprisingly advantageous properties of reduced
surface pilling and improved abrasion resistance.
[0086] It will be understood that various details of the invention
may be changed without departing from the scope of the invention.
Furthermore, the foregoing description is for the purpose of
illustration only, and not for the purpose of limitation, as the
invention is defined by the claims as set forth hereinafter.
* * * * *