U.S. patent application number 10/142533 was filed with the patent office on 2003-05-01 for dry wipe.
Invention is credited to Lim, Hyun Sung, Marin, Robert Anthony, Petroff, Jeffrey J..
Application Number | 20030082978 10/142533 |
Document ID | / |
Family ID | 26840182 |
Filed Date | 2003-05-01 |
United States Patent
Application |
20030082978 |
Kind Code |
A1 |
Lim, Hyun Sung ; et
al. |
May 1, 2003 |
Dry wipe
Abstract
A bulky fibrous fabric is provided, made by a process comprising
obtaining an unbonded, consolidated batt of fibers wherein each
fiber has a ribbon-shaped cross-section, and needling said batt to
obtain the bulky fibrous fabric. The fabric has a surface area of
at least 2 m.sup.2/g and a thickness/basis weight ratio of at least
0.005 mm/g/m.sup.2 (7 mil/oz/yd.sup.2) The fabric has utility
particularly as a dry wipe for cleaning and dusting.
Inventors: |
Lim, Hyun Sung; (Midlothian,
VA) ; Marin, Robert Anthony; (Midlothian, VA)
; Petroff, Jeffrey J.; (Hermitage, TN) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY
LEGAL PATENT RECORDS CENTER
BARLEY MILL PLAZA 25/1128
4417 LANCASTER PIKE
WILMINGTON
DE
19805
US
|
Family ID: |
26840182 |
Appl. No.: |
10/142533 |
Filed: |
May 9, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60292060 |
May 18, 2001 |
|
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Current U.S.
Class: |
442/337 ;
442/327; 442/334; 442/335; 442/402; 442/408 |
Current CPC
Class: |
Y10T 442/682 20150401;
A47L 13/16 20130101; D01D 5/11 20130101; Y10T 442/608 20150401;
D04H 1/495 20130101; D04H 1/724 20130101; Y10T 442/689 20150401;
Y10T 442/60 20150401; Y10T 442/609 20150401; Y10T 442/611 20150401;
D04H 1/46 20130101 |
Class at
Publication: |
442/337 ;
442/327; 442/334; 442/335; 442/402; 442/408 |
International
Class: |
D04H 003/10; D04H
001/00; D04H 003/00; D04H 005/00; D04H 005/02; D04H 013/00; D04H
001/46 |
Claims
What is claimed is:
1. A bulky fibrous fabric comprising a batt of fibers each fiber
having a ribbon-shaped cross-section, the batt having a surface
area of at least 2 m2/g and a thickness/basis weight ratio of at
least 0.005 mm/g/m.sup.2 (7 mil/oz/yd.sup.2).
2. A bulky fibrous fabric made by a process comprising: a)
obtaining an unbonded, consolidated batt of fibers wherein each
fiber has a ribbon-shaped cross-section; and b) needling said batt
to obtain the bulky fibrous fabric having a surface area of at
least 2 m.sup.2/g and a thickness/basis weight ratio of at least
0.005 mm/g/m.sup.2 (7 mil/oz/yd.sup.2).
3. The bulky fibrous fabric of claim 2 wherein the batt is made
from flash-spun plexifilamentary film-fibril web.
4. The bulky fibrous fabric of claim 2 or claim 3 wherein the
needling is performed by hydroentangling.
5. The bulky fibrous fabric of claim 2 or claim 3 wherein the
needling is performed by needlepunching.
6. The bulky fibrous fabric of claim 1 wherein the bulky fibrous
fabric is a nonwoven fabric and the fibers are polyolefin.
7. The bulky fibrous fabric of claim 1 wherein the bulky fibrous
fabric is a nonwoven fabric and the fibers are polyethylene.
8. The bulky fibrous fabric of claim 6 wherein the surface area is
between 2 and 30 m.sup.2/g and the thickness/basis weight ratio is
between 0.005 and 0.0075 mm/g/m.sup.2.
9. A bulky nonwoven fabric made by a process comprising: a)
obtaining an unbonded, consolidated flash-spun batt; b)
needlepunching said flash-spun batt to obtain the bulky nonwoven
fabric having a surface area of at least 2 m.sup.2/g, a
thickness/basis weight ratio of at least 0.005 mm/g/m.sup.2, a
thickness of at least 0.20 mm and a basis weight of between 37 and
78 g/m.sup.2.
10. A dry wipe useful for cleaning and dusting made from the bulky
nonwoven fabric according to any of the preceding claims.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a needled fibrous batt made from
fibers having a ribbon-shaped cross-section.
BACKGROUND OF THE INVENTION
[0002] There exists a need for a material in the form of a dry wipe
for dusting and cleaning which attracts and entraps dust and dirt
particles during use more effectively than existing dry wipes and
which may be manufactured more economically than existing dry
wipes.
[0003] Nonwoven dry wipes containing spunlaced layers of polyester
web and scrim are commercially available. Examples of such dry
wipes are Swiffer.RTM., available from The Procter & Gamble
Company, Cincinnati, Ohio, and Grab-It.RTM.), available from S. C.
Johnson & Son, Inc., Racine, Wis., which are generally made by
needling round polyester staple fibers into a scrim. These wipes
are electrostatically charged to attract dirt and dust, and the
three-dimensional structure of the webs used is open so that dirt
particles are trapped by the wipes. Another example of a dry dust
wipe is Scotch-Brite.RTM., available from Minnesota Mining and
Manufacturing Company, St. Paul, Minn., made from spunlaced webs of
polyester staple fibers having longitudinal grooves therein.
[0004] U.S. Pat. No. 5,290,628 (Lim et al.) discloses a process for
hydraulically needling a web of staple fibers into an unbonded
flash spun web made of continuous plexifilaments to form a
spunlaced nonwoven fabric. The flash spun web may optionally be
bonded to increase the level of permeability of the nonwoven
fabric. Disclosed as end uses for the nonwoven fabric are
filtration applications, and bulky, downproof and featherproof
barrier liners for garments, sleeping bags, pillows, comforters and
the like.
[0005] U.S. Pat. No. 4,704,321 (Zafiroglu) discloses a nonwoven
fabric, useful as a wipe-cloth, comprising a layer of nonbonded,
polyethylene plexifilamentary film-fibril strands, the layer being
stitched through with thread that forms spaced apart rows of
stitches extending along the length of the fabric. Zafiroglu found
that standard thermally bonded plexifilamentary sheets were not
functional for wiping cloths because after thermal bonding to
generate structural integrity the dust retention was inadequate,
and the non thermally bonded, cold consolidated sheet lacked
sufficient surface stability for a wiping cloth.
[0006] Japanese patent application Hei 4-196066, assigned to Japan
Vilene Co. Ltd., discloses a nonwoven fabric cleaning wipe having
superior dust attracting ability, and a process for making such a
wipe.
SUMMARY OF THE INVENTION
[0007] The invention provides a bulky fibrous fabric comprising a
batt of fibers each fiber having a ribbon-shaped cross-section, the
batt having a surface area of at least 2 m.sup.2/g and a
thickness/basis weight ratio of at least 0.005 mm/g/m.sup.2.
[0008] In another embodiment of the invention, a bulky fibrous
fabric is provided by a process comprising:
[0009] a) obtaining an unbonded, consolidated batt of fibers
wherein each fiber has a ribbon-shaped cross-section; and
[0010] b) needling said batt to obtain the bulky fibrous fabric
having a surface area of at least 2 m.sup.2/g and a thickness/basis
weight ratio of at least 0.005 mm/g/m.sup.2.
DETAILED DESCRIPTION OF THE INVENTION
[0011] 30 The process by which the bulky fibrous fabric of the
invention is made will now be described in detail. A batt of
fibers, each individual fiber having a ribbon-shaped cross-section,
is obtained. By "ribbon-shaped" is meant that the average aspect
ratio of the individual fiber cross-section is between 1.4 and 6.8.
The batt of fibers may be obtained by a variety of known methods.
One known method is for different cross-sectional shaped melt-spun
fibers, such as star-shaped fibers, to be spunlaced and
subsequently broken into smaller ribbon-shaped fibers.
[0012] Preferably, the batt consists of overlapping continuous
plexifilamentary film-fibril strands, formed by flash-spinning
techniques generally described in U.S. Pat. No. 3,851,023
(Brethauer et al.), herein incorporated by reference. The
film-fibrils are very thin ribbon-like fibrous elements, which are
generally less than 20 microns thick. The cross-section of each
fiber in a plexifilamentary strand is generally ribbon-shaped.
[0013] Preferably, the flash-spun batt is formed from polyolefin
polymer, and more preferably, high density polyethylene polymer.
The spin agent with which the polymer is mixed is preferably a
blend of pentane and cyclopentane. The spin agent may also be a
refrigerant such as Freon@, available from E. I. du Pont de Nemours
and Company, Inc., Wilmington, Del.
[0014] In order to achieve the desired bulkiness in the final
product, the percentage of polymer in the polymer-spin agent
mixture is preferably between 15 and 25%, most preferably 17%. The
temperature of the polymer and spin agent mixture just prior to
being emitted through the spin orifice should be maintained at
between 185 and 200 degrees C., most preferably 190 degrees C.
[0015] As described in U.S. Pat. No. 3,851,023, the
plexifilamentary film-fibril strands are electrostatically charged
in order to pin them to the moving belt on which they are collected
as they are spun. The electrostatic charge imparted is high enough
to overcome the vapor blast or high turbulence that may exist in
the web forming chamber.
[0016] By "consolidated" is meant that the as-formed batt has been
lightly compressed by a nip roll so that it may be handled as a
sheet. By "unbonded" is meant that the batt has not been further
bonded by chemical or thermal means, such as by compaction by
heated rolls or plates, so that the batt has not become a coherent
sheet. In the preferred embodiment in which the batt is obtained by
flash spinning, the individual plexifilamentary webs which overlap
one another to make up the unbonded, consolidated batt are held
together in such a way that the batt may be handled as a sheet but
the individual webs may be easily pulled away from the surface of
the batt.
[0017] The batt is needled in order to form the bulky fibrous
fabric of the invention. The needling may take the form of
hydroentangling, such as described in U.S. Pat. No. 3,485,706. As
stated in U.S. Pat. No. 3,485,706, the hydroentangling is carried
out by subjecting the batt to high pressure liquid streams of at
least 200 psig while supported by an apertured member, such as
perforated plate or woven wire screen. The number of jets, jet
type, jet pressure and apertured member can be varied to achieve
various fabric strength, surface stability and thickness.
[0018] Preferably, the needling is carried out by needlepunching in
a needle machine to obtain the fabric of the invention having a
thickness of at least 0.20 millimeters, a basis weight of between
37 and 78 g/m.sup.2, and a thickness/basis weight ratio of at least
0.005 mm/g/m.sup.2 (7 mil/oz/yd.sup.2). The needle density, or
"punch density," is between 60 and 500/cm.sup.2, preferably between
200 and 300/cm.sup.2, on each side of the batt. The needle
penetration is between 5 and 10 mm on each surface of the batt,
preferably about 5 mm. The needle pattern is random such that the
needle punches are approximately evenly spaced across both surfaces
of the batt.
[0019] Since the bulky fibrous fabric of the invention is obtained
by simply needling an unbonded, consolidated batt of fibers, the
bulky fibrous fabric may be manufactured more economically than
existing dry dust wipes made by needling staple fibers into a
scrim.
Test Methods
[0020] Basis Weight was determined by ASTM D-3776, which is hereby
incorporated by reference, and is reported in g/m.sup.2.
[0021] Tensile Strength was determined by ASTM D 5035-95, which is
hereby incorporated by reference, with the following modifications.
In the test a 2.54 cm by 20.32 cm (1 inch by 8 inch) sample was
clamped at opposite ends of the sample. The clamps were attached
12.7 cm (5 inches) from each other on the sample. The sample was
pulled steadily at a speed of 5.08 cm/min (2 inches/min) until the
sample broke. The force at break was recorded in pounds/inch and
converted to Newtons/cm as the breaking tensile strength.
[0022] Thickness was determined by ASTM D177-64, which is hereby
incorporated by reference, and is reported in millimeters.
[0023] Grab Tensile Strength was determined by ASTM D 5034-95,
which is hereby incorporated by reference, recorded in pounds/inch
and converted to Newtons/cm.
[0024] Elongation to Break of a sheet is a measure of the amount a
sheet stretches prior to breaking in a strip tensile test. A 2.54
cm (1 inch) wide sample is mounted in the clamps, set 12.7 cm (5
inches) apart, of a constant rate of extension tensile testing
machine such as an Instron table model tester. A continuously
increasing load is applied to the sample at a crosshead speed of
5.08 cm/min (2 inches/min) until failure. The measurement is given
in percentage of stretch prior to failure. The test generally
follows ASTM D 5035-95.
[0025] Grab Elongation to Break was determined by ASTM D5034-95,
which is hereby incorporated by reference, and recorded in %.
[0026] Density was calculated from measured basis weight divided by
measured thickness and is reported in gram/cm.sup.3.
[0027] Void Fraction was calculated as (1-calculated
density/0.95).times.100 and is reported in %.
[0028] Wiping Performance Test is a measure of a material's
cleaning performance as a dust mop. For the test results reported
herein, three test environments were used, referred to as Home,
Light Industrial and Heavy Industrial. The Home environment was the
floor of an office area which was cleaned daily. The Light
Industrial environment was a busy hallway in a manufacturing area
which had more traffic than the Home environment and was not
cleaned daily. The Heavy Industrial environment had forklift truck
traffic and was never cleaned. The materials to be tested were cut
into samples measuring approximately 5 inches by 11 inches. Each
sample was weighed and the weight recorded. Two samples to be
compared were secured to the bottom surface of a dry mop with a
flat, smooth rubber bottom surface. The mopping surface of the mop
was approximately 10 inches by 3 inches. The mop was pushed over a
fifty foot section of the floor. The samples were then removed from
the mop and folded in such a way that the dust collected by each
sample was held within that sample. Each sample was reweighed to
determine the amount of dust collected by that sample. The percent
performance was determined by dividing the dust collected by the
dust collected by the incumbent, or comparison sample, and
multiplying by 100%. This means that the incumbent will always have
100% performance, while the invention example will have a percent
relative to the incumbent. Values less than 100% indicate inferior
performance, while values greater than 100% indicate superior
performance. Seven to ten sample pairs were run for each
environment and the result is the average.
[0029] Fiber Surface Stability Test is a measure of how cohesive a
surface is when exposed to a destructive external force. For this
test, the samples were exposed to standard Scotch transparent tape,
available from 3M, St. Paul, Minn. Four measurements were taken on
one surface of the sample and four on the other. Eight (8)
seven-inch pieces of tape were cut and weighed, and the initial
weight recorded. Each piece of tape was applied to the surface to
be tested and rubbed evenly to insure contact between the tape and
the sample surface. The tape is then pulled away from the sample,
then reapplied and pulled away for a total of five times for each
piece of tape. Each piece of tape is weighed a second time and the
final weight recorded. The final and initial weights for each piece
of tape were used to calculate the weight of the fibers removed
from the sample surface. An average was calculated for each side of
the sample. The more fiber lost by the surface of the sample, the
more unstable the surface of the sample is. The results are
reported in grams.
[0030] Surface Area is calculated from the amount of nitrogen
absorbed by a sample at liquid nitrogen temperatures by means of
the Brunauer-Emmet-Teller equation and is given in m.sup.2/g. The
nitrogen absorption is determined using a Stohlein Surface Area
Meter manufactured by Standard Instrumentation, Inc., Charleston,
W. Va. The test method applied is found in the J. Am. Chem. Soc.,
V. 60 p. 309-319 (1938).
EXAMPLES 1-13
[0031] Flash spun unbonded batts were obtained by flash spinning
high density polyethylene at various concentrations in a blend of
pentane and cyclopentane spin agent at various temperatures by a
process as described in Brethauer. The batts were lightly
consolidated using a nip roll. The spinning conditions (percent
polymer in spin agent and spinning temperature) and properties
measured for each of these batts are listed as Comparative Examples
1-6 in Table 1.
[0032] The batts were then needlepunched in a needle machine using
a 4500 needles per meter board on each of the top and bottom
surfaces. Each batt was needled at a punch density of 60/cm.sup.2
on each side and a needle penetration of 10 mm on the top surface
and 5 mm on the bottom. A random needle pattern was used. The
output speed was 6-7 meters per minute. The properties of these
needlepunched batts, or nonwoven fabrics, are listed as Examples
1-9 in Table 1. Examples 1-9 are the nonwoven fabrics resulting
from needlepunching the batts of Comparative Examples 1-6.
Comparative Examples 1, 2, 4 and 6 provided the starting material
for Examples 1, 2, 5 and 9, respectively. Comparative Example 3
provided the starting material for both Examples 3 and 4.
Comparative Example 5 provided the starting material for Examples
6, 7 and 8.
[0033] The properties of nonwoven fabrics Swiffer.RTM.
(commercially available from The Procter and Gamble Company,
Cincinnati, Ohio) and Grab It.RTM. (commercially available from S.
C. Johnson & Son, Inc., Racine, Wis.) were measured and listed
in Table 1 as Comparative Examples 7 and 8.
[0034] The thickness/basis weight (BW) ratio is a measure of the
bulkiness of the fabric. The higher the thickness/BW, the bulkier
the fabric. The thickness/BW of the unbonded, unneedled batt
(Comparative Examples 1-6) ranges from 4.5 to 5.2 depending on the
basis weight and spinning conditions. The thickness/BW of
needlepunched fabric (Examples 1-9) ranges from 7.2 to 7.9. The
increase in thickness/BW of the needlepunched fabric is attributed
to fiber entanglement caused by the action of the needles. This
phenomenon is contrary to typical needlepunching of webs where the
needles cause the web to consolidate and lower the thickness. This
increased thickness/BW ratio, or bulkiness, is important for the
wiping performance of the fabric of the invention, since it
provides greater capacity for the fabric to capture and store dust
and dirt particles.
[0035] Slight increases in the mechanical properties of Examples
1-9 as compared with Comparative Examples 1-6, specifically grab
tensile strength, grab elongation to break, tensile strength and
elongation to break, are attributed to the fiber entanglements
caused by the needlepunching process. The mechanical properties are
increased with increasing basis weight. A 54 g/m.sup.2
needlepunched fabric has a similar range of mechanical properties
as the current incumbent wipe products.
[0036] Table 2 illustrates the effects on surface stability and
wiping performance when the spinning conditions are held constant
and the needling density and penetration are varied. Examples 8 and
10-13 are based on the starting batt material of Comparative
Example 5, and each is needlepunched at a different needle density
and penetration (on the upper and lower sides), listed in Table 2.
Surface area measurements are also included in Table 2.
[0037] Surface area measurements were made on the existing dust
wipe materials, Swiffer.RTM. and Grab-It.RTM. (Comparative Examples
7 and 8), and the result was 0.0 m.sup.2/g, meaning less than 0.1
m.sup.2/g.
1TABLE 1 Comparison Comparison Comparison Comparison Comparison
Comparison Example 1 2 3 4 5 6 1 2 Spun condition (% polymer,
17/190 17/197 17/200 20/200 17/190 17/190 17/190 17/197 degrees C)
Basis Weight (g/m.sup.2) 41 41 54 51 54 78 37 41 Thickness (mm)
0.159 0.155 0.203 0.198 0.203 0.264 0.221 0.236 Thickness/Basis
3.90E - 06 3.80E - 06 3.80E - 06 3.90E - 06 3.80E - 06 3.40E - 06
6.00E - 06 5.80E - 06 Weight (m.sup.3/g) Density (g/cm.sup.3) 0.257
0.263 0.267 0.257 0.267 0.295 0.169 0.172 Void Fraction (%) 73 72.3
71.9 72.9 71.9 68.9 82.2 81.9 Grab Tenacity MD/CD (N/cm) 5./10 5./9
12./46 9./47 19/28 24/46 10./12 10./16 Grab Elongation MD/CD (%)
44/64 43/57 50/34 40/51 41/53 45/39 43/45 Tensile MD/CD (N/cm)
1.9/2.3 1.7/1.7 2.6/8.9 2.6/8.8 3.5/4.5 6.6/6.6 1.9/3.1 2.6/3.3
Elongation MD/CD (%) 4./15 6./13 15/23 15/23 9./13 9.4/11.4 26/27
29/28 Fiber Surface Stability: Belt side (g) 0.0975 0.0614 0.0461
0.295 0.554 0.149 0.0496 0.0505 Top side (g) 0.302 0.143 0.0667
0.0646 0.156 0.276 0.0657 0.0708 Wiping Performance (%): Home
environment 81 110 76 90 105 170 Light Industrial 81 100 87 82 90
100 130 Heavy Industrial 76 100 85 100 85 75 80 Comparison
Comparison Example 3 4 5 6 7 8 9 7 8 Spun condition (% 17/200
17/200 20/200 17/190 17/190 17/190 17/190 polymer, degrees C) Basis
Weight (g/m.sup.2) 49 51 51 56 48 51 78 64 58 Thickness (mm) 0.287
0.274 0.292 0.307 0.251 0.3 0.414 0.297 0.305 Thickness/Basis 5.90E
- 06 5.40E - 06 5.70E - 06 5.50E - 06 5.20E - 06 5.90E - 06 5.30E -
06 4.60E - 06 5.30E - 06 Weight (m.sup.3/g) Density (g/cm.sup.3)
0.171 0.186 0.174 0.183 0.192 0.17 0.189 Void Fraction (%) 82 80.4
81.7 80.7 79.8 82.1 80.1 Grab Tenacity 18/24 18/21 30/44 30/35
44/53 16/9 28/9 MD/CD (N/cm) Grab Elongation 82/55 53/30 53/34
47/43 49/36 112/78 56/71 MD/CD (%) Tensile MD/CD 4.7/7.9 3.8/8.4
7./12 7./8.8 9./16 7./2.8 17/3 (N/cm) Elongation 41/36 37/33 39/41
34/35 34/29 56/29 50/44 MD/CD (%) Fiber Surface Stability: Belt
side (g) 0.0061 0.0143 0.0148 0.0385 0.0405 0.0048 0.0122 0.0244
0.00754 Top side (g) 0.0344 0.0724 0.0236 0.0208 0.0513 0.0129
0.0045 0.0667 0.0043 Wiping Performance (%): Home environment 110
130 117/150 108 100/130 100 Light Industrial 122 117 110/120 83
107/86 100 Heavy Industrial 107 107 100/90 100 107/80 100
[0038]
2TABLE 2 Example Comparison 5 8 10 11 12 13 Spun conditions (%
polymer/degrees C) 17/190 17/190 17/190 17/190 17/190 17/190 Needle
(density/penetration upper/lower): Density (needles/cm.sup.2) 60
100 100 150 225 Penetration (upper/lower) (mm) 10./5 10.0/5 5.0/5
5.0/5 5.0/5 Basis Weight (g/m.sup.2) 54 51 51 51 51 51 Thickness
(mm) 0.203 0.3 0.31 0.297 0.312 0.368 Thickness/BW (m.sup.3/g)
3.80E - 06 5.90E - 06 6.10E - 06 5.80E - 06 6.10E - 06 7.20E - 06
Density (g/cm.sup.3) 0.267 0.17 0.164 0.172 0.163 0.138 Void
Fraction (%) 71.9 82.1 82.7 81.9 82.8 85.5 Grab Tenacity MD/CD
(N/cm) 19/28 30/35 23/28 30/31 23/22 30/31 Grab Elongation MD/CD
(%) 40/51 47/43 50/44 52/47 47/41.6 52/43.6 Tensile MD/CD (N/cm)
3.5/4.5 7/8.8 7/7.9 7.7/8.8 7.5/6.6 6.6/8.9 Elongation MD/CD (%)
9./13 34/35 32/35 29/32 27/33 30.2/34 Fiber Surface Stability: Belt
side (g) 0.554 0.0048 0.0194 0.011 0.079 0.016 Top side (g) 0.156
0.0129 0.0108 0.017 0.023 0.016 Wiping vs. Swiffer: Home
environment 76 109/130 93 138 110 150 Light Industrial 82 122/86
126 114 114 118 Heavy Industrial 100 98/80 93 100 106 107 Surface
Area (m.sup.2/g) 15.3 11.8 9.5 10.8 8.4 9.7
EXAMPLES 14-17
[0039] Flash spun unbonded batts were obtained by flash spinning
high density polyethylene at various concentrations in a blend of
pentane and cyclopentane spin agent at various temperatures by a
process as described in Brethauer. The batts were lightly
consolidated using a nip roll. The spinning conditions (percent
polymer in spin agent and spinning temperature) and properties
measured for each of these batts are listed as Comparative Examples
1-6 in Table 1.
[0040] The batts were then hydroentangled using high pressure water
on each of the top and bottom surfaces. The number of jets, jet
type, jet pressure and apertured member were varied to achieve
various fabric strength, fiber surface stability and thickness. The
properties of these hydroentangled batts, or nonwoven fabrics, are
listed as Examples 14-17 in Table 3. In each case, the batt was
supported on a first apertured member and hydroentangled by making
several passes under high pressure water jets with the line running
at 50 yards per minute. The batt was then turned over, placed on a
second apertured member and again hydroentangled by making several
passes under high pressure water jets with the line running at 50
yards per minute.
3TABLE 3 Example 14 15 16 17 Spun condition (% polymer/degrees C)
17/200 17/200 17/200 17/200 Water jet pressure Low Pressure High
Pressure Low Pressure Basis Weight (g/m.sup.2) 47 58 58 58
Thickness (mm) 0.292 0.318 0.356 0.356 Thickness/BW (m.sup.3/g)
6.20E - 06 5.50E - 06 6.10E - 06 6.10E - 06 Density (g/cm.sup.3)
Void Fraction (%) Grab Tenacity MD/CD (N/cm) 42 58 47 42 Grab
Elongation MD/CD (%) 46 34 36 44 Tensile MD/CD (N/cm) 25.4 12.2
19.2 14 Elongation MD/CD (%) 24 40 37 37 Fiber Surface Stability:
Belt side (g) 0.018 0.006 0.003 Top side (g) 0.013 0.01 0.003
Wiping vs. Swiffer: Home environment 80 130 110 Light Industrial
Heavy Industrial 95 96 91 Surface Area (m.sup.2/g) 8.6 8 6.3
7.1
EXAMPLE 14
[0041] During the first pass of hydroentangling, the batt was
supported on a first apertured member of a 75 mesh woven wire. Four
jets were used. During the second pass of hydroentangling, the batt
was supported on a second apertured member of a perforated plate
having a clover pattern with a 20 mesh sub screen. Three jets were
used. The jet hole diameters, number of holes per inch per jet, and
the jet operating pressures are listed below in Table 4.
4 TABLE 4 Hole diameter Pressure Jet (mils) Holes per inch (psi)
First Pass 1 4 80 500 2 5 40 1000 3 5 40 1500 4 5 40 1500 Second
Pass 1 4 80 300 2 5 40 500 3 5 40 1000
EXAMPLE 15
[0042] During the first pass of hydroentangling, the batt was
supported on a first apertured member of a 75 mesh woven wire. Four
jets were used. During the second pass of hydroentangling, the batt
was supported on a second apertured member of an 8 mesh woven wire.
Four jets were used. The jet parameters are listed in Table 5.
5 TABLE 5 Hole diameter Pressure Jet (mils) Holes per inch (psi)
First Pass 1 4 80 500 2 5 40 1000 3 5 40 1500 4 5 40 1500 Second
Pass 1 4 80 500 2 5 40 800 3 5 40 1000 4 5 40 1000
EXAMPLE 16
[0043] During the first pass of hydroentangling, the batt was
supported on a first apertured member of a 75 mesh woven wire. Four
jets were used. During the second pass of hydroentangling, the batt
was supported on a second apertured member of an 13 mesh woven
wire. Eight jets were used. The jet parameters are listed in Table
6.
6 TABLE 6 Hole diameter Pressure Jet (mils) Holes per inch (psi)
First Pass 1 4 80 500 2 5 40 1000 3 5 40 1500 4 5 40 1500 Second
Pass 1 4 80 300 2 4 80 500 3 5 40 800 4 5 40 1000 5 5 40 1200 6 5
40 1500 7 5 40 1700 8 5 40 1800
EXAMPLE 17
[0044] During the first pass of hydroentangling, the batt was
supported on a first apertured member of a 75 mesh woven wire.
Eight jets were used. During the second pass of hydroentangling,
the batt was supported on a second apertured member of an 8 mesh
woven wire. Eight jets were used. The jet parameters are listed in
Table 7.
7 TABLE 7 Hole diameter Pressure Jet (mils) Holes per inch (psi)
First Pass 1 4 80 300 2 5 40 500 3 5 40 800 4 5 40 1000 5 5 40 1200
6 5 40 1500 7 5 40 1800 8 5 40 1800 Second Pass 1 4 80 300 2 4 80
500 3 5 40 800 4 5 40 1000 5 5 40 1200 6 5 40 1500 7 5 40 1700 8 5
40 1800
* * * * *