U.S. patent application number 11/608271 was filed with the patent office on 2007-05-03 for fluoropolymer fiber composite bundle.
Invention is credited to Richard A. Bucher, Norman Ernest Clough, Tahi K. Egres, Robert L. Sassa.
Application Number | 20070098985 11/608271 |
Document ID | / |
Family ID | 36815994 |
Filed Date | 2007-05-03 |
United States Patent
Application |
20070098985 |
Kind Code |
A1 |
Bucher; Richard A. ; et
al. |
May 3, 2007 |
Fluoropolymer Fiber Composite Bundle
Abstract
A composite bundle for repeated stress applications comprising
at least one fiber of a high strength material, at least one fiber
of fluoropolymer, wherein the fluoropolymer fiber is present in an
amount of about 40% by weight or less.
Inventors: |
Bucher; Richard A.; (Lincoln
University, PA) ; Clough; Norman Ernest; (Landenberg,
PA) ; Egres; Tahi K.; (Newark, DE) ; Sassa;
Robert L.; (Newark, DE) |
Correspondence
Address: |
GORE ENTERPRISE HOLDINGS, INC.
551 PAPER MILL ROAD
P. O. BOX 9206
NEWARK
DE
19714-9206
US
|
Family ID: |
36815994 |
Appl. No.: |
11/608271 |
Filed: |
December 8, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11056074 |
Feb 11, 2005 |
|
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11608271 |
Dec 8, 2006 |
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Current U.S.
Class: |
428/375 |
Current CPC
Class: |
D07B 2201/2014 20130101;
D07B 2205/205 20130101; D07B 2205/2071 20130101; D07B 2201/2036
20130101; D07B 1/025 20130101; D02G 3/047 20130101; Y10T 428/2933
20150115; D07B 2205/2014 20130101; Y10T 428/2913 20150115; D07B
2201/2041 20130101; D07B 2205/2096 20130101; D07B 2205/2014
20130101; D07B 2801/10 20130101; D07B 2205/205 20130101; D07B
2801/10 20130101; D07B 2205/2071 20130101; D07B 2801/10 20130101;
D07B 2205/2096 20130101; D07B 2801/10 20130101 |
Class at
Publication: |
428/375 |
International
Class: |
D02G 3/00 20060101
D02G003/00 |
Claims
1. A composite bundle for repeated stress applications comprising:
(a) at least one high strength fiber having a tenacity of greater
than 15 g/d; and (b) at least fluoropolymer fiber comprising
expanded polytetrafluoroethylene and selected from the group
consisting of a monofilament or a multifilament; wherein said
fluoropolymer fiber is present in an amount of between about 1% and
40% by weight.
2. The composite bundle of claim 1 wherein said fluoropolymer fiber
is present in an amount of between about 1% and 35% by weight.
3. The composite bundle of claim 1 wherein said fluoropolymer fiber
is present in an amount of between about 1% and 30% by weight.
4. The composite bundle of claim 1 wherein said fluoropolymer fiber
is present in an amount of between about 1% and 25% by weight.
5. The composite bundle of claim 1 wherein said fluoropolymer fiber
is present in an amount of between about 1% and 20% by weight.
6. The composite bundle of claim 1 wherein said fluoropolymer fiber
is present in an amount of between about 1% and 15% by weight.
7. The composite bundle of claim 1 wherein said fluoropolymer fiber
is present in an amount of between about 1% and 10% by weight.
8. The composite bundle of claim 1 wherein said fluoropolymer fiber
is present in an amount of about 1% by weight.
9. The composite bundle of claim 1 wherein said fluoropolymer fiber
is a monofilament.
10. The composite bundle of claim 1 wherein said fluoropolymer
fiber is low density of less than about 1 g/cc.
11. The composite bundle of claim 1 wherein said fluoropolymer
fiber is a multifilament.
12. The composite bundle of claim 1 wherein said fluoropolymer
fiber comprises a filler.
13. The composite bundle of claim 12 wherein said filler comprises
carbon.
14. The composite bundle of claim 12 wherein said filler is
selected from the group consisting of molybdenum disulfide,
graphite, hydrocarbon, and silicone base fluid.
15. The composite bundle of claim 1 wherein the high strength fiber
is para-aramid.
16. The composite bundle of claim 1 wherein the high strength fiber
is polybenzoxazole (PBO).
17. The composite bundle of claim 1 wherein the high strength fiber
is high tenacity metal.
18. The composite bundle of claim 1 wherein the high strength fiber
is high tenacity mineral.
Description
REFERENCE TO RELATED APPLICATION
[0001] The present application is a divisional application of U.S.
patent application Ser. No. 11/056,074 filed Feb. 11, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates to a fluoropolymer composite
bundle and, more particularly, to ropes and other textiles made of
composite bundles including fluoropolymers such as
polytetrafluoroethylene (PTFE).
Definition of Terms
[0003] As used in this application, the term "fiber" means a
threadlike article as indicated at 16 and 18 of FIG. 1. Fiber as
used herein includes monofilament fiber and multifilament fiber. A
plurality of fibers may be combined to form a "bundle" 14 as shown
in FIG. 1. When different types of fibers are combined to form a
bundle, it is referred to herein as a "composite bundle." A
plurality of bundles may be combined to form a "bundle group" 12 as
shown in FIG. 1. A plurality of bundle groups may be combined to
form a "rope" 10 as shown in FIG. 1 (although alternative rope
constructions are contemplated and included in this invention as
described herein).
[0004] "Repeated stress applications" as used herein means those
applications in which fibers are subjected to tensile, bending, or
torsional forces, or combinations thereof, that result in abrasion
and/or compression failures of the fiber, such as in ropes for
mooring and heavy lifting applications, including, for instance,
oceanographic, marine, and offshore drilling applications, and in
ropes which are bent under tension against a pulley, drum, or
sheave.
[0005] "High strength fiber" as used herein refers to a fiber
having a tenacity of greater than 15 g/d.
[0006] "Abrasion rate" as used herein means the quotient of the
decrease in the break force of a sample and the number of abrasion
test cycles (as further defined in Example 1).
[0007] "Ratio of break strengths after abrasion test" as used
herein means the quotient of the break strength after the abrasion
test for a given test article that includes the addition of
fluoropolymer fibers and the break strength after the abrasion test
for the same construction of the test article without the addition
of the fluoropolymer fibers.
[0008] "Low density" as used herein means density less than about 1
g/cc.
BACKGROUND OF THE INVENTION
[0009] High-strength fibers are used in many applications. For
example, polymeric ropes are widely used in mooring and heavy
lifting applications, including, for instance, oceanographic,
marine, and offshore drilling applications. They are subjected to
high tensile and bending stresses in use as well as a wide range of
environmental challenges. These ropes are constructed in a variety
of ways from various fiber types. For example, the ropes may be
braided ropes, wire-lay ropes, or parallel strand ropes. Braided
ropes are formed by braiding or plaiting bundle groups together as
opposed to twisting them together. Wire-lay ropes are made in a
similar manner as wire ropes, where each layer of twisted bundles
is generally wound (laid) in the same direction about the center
axis. Parallel strand ropes are an assemblage of bundle groups held
together by a braided or extruded jacket.
[0010] Component fibers in ropes used in mooring and heavy lifting
applications include high modulus and high strength fibers such as
ultra high molecular weight polyethylene (UHMWPE) fibers.
DYNEEMA.RTM. and SPECTRA.RTM. brand fibers are examples of such
fibers. Liquid crystal polymer (LCP) fibers such as liquid crystal
aromatic polyester sold under the tradename VECTRAN.RTM. are also
used to construct such ropes. Para-aramid fibers, such as
Kevlar.RTM. fiber, likewise, also have utility in such
applications.
[0011] The service life of these ropes is compromised by one or
more of three mechanisms. Fiber abrasion is one of the mechanisms.
This abrasion could be fiber-to-fiber abrasion internally or
external abrasion of the fibers against another object. The
abrasion damages the fibers, thereby decreasing the life of the
rope. LCP fibers are particularly susceptible to this failure
mechanism. A second mechanism is another consequence of abrasion.
As rope fibers abrade each other during use, such as when the rope
is bent under tension against a pulley or drum, heat is generated.
This internal heat severely weakens the fibers. The fibers are seen
to exhibit accelerated elongation rates or to break (i.e., creep
rupture) under load. The UHMWPE fibers suffer from this mode of
failure. Another mechanism is a consequence of compression of the
rope or parts of the rope where the rope is pulled taught over a
pulley, drum, or other object.
[0012] Various solutions to address these problems have been
explored. These attempts typically involve fiber material changes
or construction changes. The use of new and stronger fibers is
often examined as a way to improve rope life. One solution involves
the utilization of multiple types of fibers in new configurations.
That is, two or more types of fibers are combined to create a rope.
The different type fibers can be combined in a specific manner so
as to compensate for the shortcoming of each fiber type. An example
of where a combination of two or more fibers can provide property
benefits are improved resistance to creep and creep rupture (unlike
a 100% UHMWPE rope) and improved resistance to self-abrasion
(unlike a 100% LCP rope). All such ropes, however, still perform
inadequately in some applications, failing due to one or more of
the three above-mentioned mechanisms.
[0013] Rope performance is determined to a large extent by the
design of the most fundamental building block used to construct the
rope, the bundle of fibers. This bundle may include different types
of fibers. Improving bundle life generally improves the life of the
rope. The bundles have value in applications less demanding than
the heavy-duty ropes described above. Such applications include
lifting, bundling, securing, and the like. Attempts have been made
to combine fiber materials in such repeated stress applications.
For example, UHMWPE fibers and high strength fibers, such as LCP
fibers, have been blended to create a large diameter rope with
better abrasion resistance, but they are still not as effective as
desired.
[0014] The abrasion resistance of ropes for elevators has been
improved by utilizing high modulus synthetic fibers, impregnating
one or more of the bundles with polytetrafluoroethylene (PTFE)
dispersion, or coating the fibers with PTFE powder. Typically such
coatings wear off relatively quickly. Providing a jacket to the
exterior of a rope or the individual bundles has also been shown to
improve the rope life. Jackets add weight, bulk, and stiffness to
the rope, however.
[0015] Fiberglass and PTFE have been commingled in order to extend
the life of fiberglass fibers. These fibers have been woven into
fabrics. The resultant articles possess superior flex life and
abrasion resistance compared to fiberglass fibers alone.
Heat-meltable fluorine-containing resins have been combined with
fibers, in particular with cotton-like material fibers, The
resultant fiber has been used to create improved fabrics. PTFE
fibers have been used in combination with other fibers in dental
floss and other low-load applications, but not in repeated stress
applications described herein.
[0016] In sum, none of the known attempts to improve the life of
ropes or cable have provided sufficient durability in applications
involving both bending and high tension. The ideal solution would
benefit both heavy-duty ropes and smaller diameter configurations,
such as bundles.
SUMMARY OF THE INVENTION
[0017] The present invention provides a composite bundle for
repeated stress applications comprising at least one high strength
fiber, and at least one fluoropolymer fiber, wherein the
fluoropolymer fiber is present in an amount of about 40% by weight
or less.
[0018] In a preferred embodiment, the high strength fiber is liquid
crystal polymer or ultrahigh molecular weight polyethylene, or
combinations thereof.
[0019] Preferred weight percentages of the fluoropolymer fiber are
about 35% by weight or less, about 30% by weight or less, about 25%
by weight or less, about 20% by weight or less, about 15% by weight
or less, about 10% by weight or less, and about 5% by weight or
less.
[0020] Preferably, the composite bundle has a ratio of break
strengths after abrasion test of at least 1.8, even more preferably
of at least 3.8, and even more preferably of at least 4.0.
Preferably, the fluoropolymer fiber is an ePTFE fiber, which may be
a monofilament or multifilament, either of which can be low or high
density.
[0021] In alternative embodiments, the fluoropolymer fiber
comprises a filler such as molybdenum disulfide, graphite, or
lubricant (hydrocarbon, or silicone base fluid).
[0022] In alternative embodiments, the high strength fiber is
para-aramid, liquid crystal polyester, polybenzoxazole (PBO), high
tenacity metal, high tenacity mineral, or carbon fiber.
[0023] In another aspect, the invention provides for a method of
reducing abrasion- or friction-related wear of a fiber bundle in
repeated stress applications while substantially maintaining the
strength of the fiber bundle comprising the step of including in
the fiber bundle at least one filament of fluoropolymer.
[0024] In other aspects, the invention provides a rope, belt, net,
sling, cable, woven fabric, nonwoven fabric, or tubular textile
made from the inventive composite bundle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is an exploded view of an exemplary embodiment of a
rope made according to the present invention.
[0026] FIG. 2 is an illustration of an abrasion resistance test
set-up.
[0027] FIG. 3 is an illustration of a fiber sample twisted upon
itself as used in the abrasion resistance test.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The inventors have discovered that a relatively small weight
percent of a fluoropolymer fiber added to a bundle of high strength
fibers produces a surprisingly dramatic increase in abrasion
resistance and wear life.
[0029] The high-strength fibers used to form ropes, cables, and
other tensile members for use in repeated stress applications
include ultra high molecular weight polyethylene (UHMWPE) such as
DYNEEMA.RTM. and SPECTRA.RTM. brand fibers, liquid crystal polymer
(LCP) fibers such as those sold under the tradename VECTRAN.RTM.,
other LCAPs, PBO, high performance aramid fibers, para-aramid
fibers such as Kevlar.RTM. fiber, carbon fiber, nylon, and steel.
Combinations of such fibers are also included, such as UHMWPE and
LCP, which is typically used for ropes in oceanographic and other
heavy lifting applications.
[0030] The fluoropolymer fibers used in combination with any of the
above fibers according to preferred embodiments of the present
invention include, but are not limited to, polytetrafluoroethylene
(PTFE) (including expanded PTFE (ePTFE) and modified PTFE),
fluorinated ethylenepropylene (FEP),
ethylene-chlorotrif-luoroethylene (ECTFE),
ethylene-tetrafluoroethylene (ETFE), or perfluoroalkoxy polymer
(PFA). The fluoropolymer fibers include monofilament fibers,
multifilament fibers, or both. Both high and low density
fluoropolymer fibers may be used in this invention.
[0031] Although the fluoropolymer fiber typically has less strength
than the high-strength fiber, the overall strength of the combined
bundle is not significantly compromised by the addition of the
fluoropolymer fiber or fibers (or replacement of the high strength
fibers with the fluoropolymer fiber or fibers). Preferably, less
than 10% strength reduction is observed after inclusion of the
fluoropolymer fibers.
[0032] The fluoropolymer fibers are preferably combined with the
high-strength fibers in an amount such that less than about 40% by
weight of fluoropolymer fiber are present in the composite bundle.
More preferable ranges include less than about 35% less than about
30%, less than about 25%, less than about 20%, less than about 15%,
less than about 10%, less than about 5%, and about 1%.
[0033] Surprisingly, even at these low addition levels, and with
only a moderate (less than about 10%) reduction in strength, the
composite bundles of the present invention show a dramatic increase
in abrasion resistance and thus in wear life. In some cases, the
ratio of break strengths after abrasion tests has exceeded 4.0, as
illustrated by the examples presented below (See Table 3).
Specifically, as demonstrated in Examples 1-4 below, the break
force of a fiber bundle including PTFE and a high-strength fiber
after a given number of abrasion testing cycles are dramatically
higher than that of the high-strength fiber alone. The abrasion
rates, therefore, are lower for PTFE fiber-containing composite
bundles than for the same constructions devoid of PTFE fibers.
[0034] Without being limited by theory, it is believed that it is
the lubricity of the fluoropolymer fibers that results in the
improved abrasion resistance of the composite bundles, In this
aspect, the invention provides a method of lubricating a rope or
fiber bundle by including a solid lubricous fiber to it.
[0035] The fluoropolymer fibers optionally include fillers. Solid
lubricants such as graphite, waxes, or even fluid lubricants like
hydrocarbon oils or silicone oils may be used. Such fillers impart
additional favorable properties to the fluoropolymer fibers and
ultimately to the rope itself. For example, PTFE filled with carbon
has improved thermal conductivity and is useful to improve the heat
resistance of the fiber and rope. This prevents or at least retards
the build-up of heat in the rope, which is one of the contributing
factors to rope failure. Graphite or other lubricious fillers may
be used to enhance the lubrication benefits realized by adding the
fluoropolymer fibers.
[0036] Any conventionally known method may be used to combine the
fluoropolymer fibers with the high-strength fibers. No special
processing is required. The fibers may be blended, twisted,
braided, or simply co-processed together with no special
combination processing. Typically the fibers are combined using
conventional rope manufacturing processes known to those skilled in
the art.
EXAMPLES
[0037] In the examples presented below, abrasion resistance and
wear life are tested on various fiber bundles. The results are
indicative of the effects seen in ropes constructed from the
bundles of the present invention, as will be appreciated by those
skilled in the art.
[0038] Specifically, abrasion rate is used to demonstrate abrasion
resistance. The wear life is demonstrated by certain examples in
which the fiber bundles (with and without the inventive combination
of fluoropolymer fibers) are cycled to failure. The results are
reported as cycles to failure. More detail of the tests is provided
below.
Testing Methods
Mass Per Unit Length and Tensile Strength Measurements
[0039] The weight per unit length of each individual fiber was
determined by weighing a 9 m length sample of the fiber using a
Denver Instruments. Inc. Model AA160 analytical balance and
multiplying the mass, expressed in grams, by 1000 thereby
expressing results in the units of denier. With the exception of
Examples 6a and 6b, all tensile testing was conducted at ambient
temperature on a tensile test machine (Zellweger USTER.RTM.
TENSORAPID 4, Uster, Switzerland) equipped with pneumatic fiber
grips, utilizing a gauge length of 350 mm and a cross-head speed of
330 mm/min. The strain rate, therefore, was 94.3%/min. For Examples
6a and 6b, tensile testing was conducted at ambient temperature on
an INSTRON 5567 tensile test machine (Canton, Mass.) equipped with
pneumatic horseshoe fiber grips, again utilizing a gauge length of
350 mm, a cross-head speed of 330 mm/min and, hence, a strain rate
of 94.3%/min. The peak force, which refers to the break strength of
the fiber, was recorded. Four samples were tested and their average
break strength was calculated. The average tenacity of the
individual fiber sample expressed in g/d was calculated by dividing
the average break strength expressed in grams by the denier value
of the individual fiber, In the case of testing composite bundles
or bundle groups, the average tenacity of these samples was
calculated by dividing the average break strength of the composite
bundle or bundle group (in units of grams), by the weight per
length value of the composite bundle or bundle group (expressed in
units of denier). The denier value of the composite bundle or
bundle group can be determined by measuring the mass of the sample
or by summing the denier values of the individual components of the
sample.
Density Measurement
[0040] Fiber density was determined using the following technique.
The fiber volume was calculated from the average thickness and
width values of a fixed length of fiber and the density calculated
from the fiber volume and mass of the fiber. A 2-meter length of
fiber was placed on an A&D FR-300 balance and the mass noted in
grams (C). The thickness of the fiber sample was then measured at 3
points along the fiber using an AMES (Waltham, Mass., USA) Model
LG3600 thickness gauge. The width of the fiber was also measured at
3 points along the same fiber sample using an LP-6 Profile
Projector available from Ehrenreich Photo Optical Ind. Inc. Garden
City, N.Y. Average values of thickness and width were then
calculated and the volume of the fiber sample was determined (D).
The density of the fiber sample was calculated as follows: fiber
sample density (g/cc)=C/D. Abrasion Resistance Measurement
[0041] The abrasion test was adapted from ASTM Standard Test Method
for Wet and Dry Yarn-on-Yarn Abrasion Resistance (Designation D
6611-00). This test method applies to the testing of yarns used in
the construction of ropes, in particular, in ropes intended for use
in marine environments.
[0042] The test apparatus is shown in FIG. 2 with three pulleys 21,
22, 23 arranged on a vertical frame 24. Pulleys 21, 22, 23 were
22.5 mm in diameter. The centerlines of upper pulleys 21, 23 were
separated by a distance of 140 mm. The centerline of the lower
pulley 22 was 254 mm below a horizontal line connecting the upper
pulley 21, 23 centerlines. A motor 25 and crank 26 were positioned
as indicated in FIG. 2. An extension rod 27 driven by the
motor-driven crank 26 through a bushing 28 was employed to displace
the test sample 30 a distance of 50.8 mm as the rod 27 moved
forward and back during each cycle. A cycle comprised a forward and
back stroke. A digital counter (not shown) recorded the number of
cycles. The crank speed was adjustable within the range of 65 and
100 cycles per minute.
[0043] A weight 31 (in the form of a plastic container into which
various weights could be added) was tied to one end of sample 30 in
order to apply a prescribed tension corresponding to 1.5% of the
average break strength of the test sample 30. The sample 30, while
under no tension, was threaded over the third pulley 23, under the
second pulley 22, and then over the first pulley 21, in accordance
with FIG. 2. Tension was then applied to the sample 30 by hanging
the weight 31 as shown in the figure. The other end of the sample
30 was then affixed to the extension rod 27 attached to the motor
crank 26. The rod 27 had previously been positioned to the highest
point of the stroke, thereby ensuring that the weight 31 providing
the tension was positioned at the maximum height prior to testing.
The maximum height was typically 6-8 cm below the centerline of the
third pulley 23. Care was taken to ensure that the fiber sample 30
was securely attached to the extension rod 27 and weight 31 in
order to prevent slippage during testing.
[0044] The test sample 30 while still under tension was then
carefully removed from the second, lower, pulley 22. A cylinder
(not shown) of approximately 27 mm diameter was placed in the
cradle formed by the sample 30 and then turned 180.degree. to the
right in order to effect a half-wrap to the sample 30. The cylinder
was turned an additional 180.degree. to the right to complete a
full 3600 wrap. The twisting was continued in 180.degree.
increments until the desired number of wraps was achieved. The
cylinder was then carefully removed while the sample 30 was still
under tension and the sample 30 was replaced around the second
pulley 22. By way of example, three complete wraps (3.times.3600)
for a fiber sample 30 is shown in FIG. 3. The only deviation from
the twist direction during wrapping would arise in the case of the
sample being a twisted multifilament. In this case, the direction
of this twist direction must be in the same direction as the
inherent twist of the multifilament fiber.
[0045] In tests in which the test sample consists of two or more
individual fibers, including at least one fiber of fluoropolymer,
the following modified procedure was followed, After securing the
test sample to the weight, the fluoropolymer fiber or fibers were
placed side by side to the other fibers without twisting. Unless
stated otherwise, the fluoropolymer fiber or fibers were always
placed closest to the operator. The subsequent procedure for
wrapping the fibers was otherwise identical to that outlined
above.
[0046] Once the test setup was completed, the cycle counter was set
to zero, the crank speed was adjusted to the desired speed, and the
gear motor was started. After the desired number of cycles was
completed, the gear motor was stopped and the abraded test sample
was removed from the weight and the extension rod. Each test was
performed four times.
[0047] The abraded test samples were then tensile tested for break
strength and the results were averaged. The average tenacity was
calculated using the average break strength value and the total
weight per unit length value of the fiber or composite bundle
sample.
[0048] In one example, the abrasion test continued until the fiber
or composite bundle completely broke under the tension applied. The
number of cycles were noted as the cycles to failure of the sample.
In this example, three samples were tested and the average cycles
to failure calculated.
Example 1
[0049] A single ePTFE fiber was combined with a single liquid
crystal polymer (LCP) fiber (Vectran.RTM., Celanese Acetate LLC,
Charlotte, N.C.) and subjected to the afore-mentioned abrasion
test. The results from this test were compared against the results
from the test of a single LCP fiber.
[0050] An ePTFE monofilament fiber was obtained (HT400 d
Rastex.RTM. fiber, W.L. Gore and Associates, Inc., Elkton Md.).
This fiber possessed the following properties: 425 d weight per
unit length, 2.29 kg break force, 5.38 g/d tenacity and 1.78 g/cc
density. The LCP fiber had a weight per unit length of 1567 d, a
34.55 kg break force, and a tenacity of 22.0 g/d.
[0051] The two fiber types were combined by simply holding them so
that they were adjacent to one another, That is, no twisting or
other means of entangling was applied. The weight percentages of
these two fibers when combined were 79% LCP and 21% ePTFE. The
weight per unit length of the composite bundle was 1992 d. The
break force of the composite bundle was 33.87 kg. The tenacity of
the composite bundle was 17.0 g/d. Adding the single ePTFE fiber to
the LCP changed the weight per unit length, break force, and
tenacity by +27%, -2%, and -23%, respectively. Note that the
decrease in break force associated with the addition of the ePTFE
monofilament fiber was attributed to the variability of the
strength of the fibers.
[0052] These fiber properties, as well as those of all the fibers
used in Examples 2 through 8, are presented in Table 1.
[0053] A single LCP fiber was tested for abrasion resistance
following the procedure described previously. Five complete wraps
were applied to the fiber. The test was conducted at 100 cycles per
minute, under 518 g tension (which corresponded to 1.5% of the
break force of the LCP fiber).
[0054] The composite bundle of the single LCP fiber and the ePTFE
monofilament fiber was also tested for abrasion resistance in the
same manner. Five complete wraps were applied to the composite
bundle. The test was conducted at 100 cycles per minute and under
508 g tension (which corresponded to 1.5% of the break force of the
fiber combination).
[0055] The abrasion tests were run for 1500 cycles, after which
point the test samples were tensile tested to determine their break
force. The composite bundle and the LCP fiber exhibited 26.38 kg
and 13.21 kg break forces after abrasion, respectively. Adding the
single PTFE monofilament fiber to the single LCP fiber increased
the post-abrasion break force by 100%. Thus, adding the single
ePTFE monofilament fiber changed the break force by -2% prior to
testing and resulted in a 100% higher break force upon completion
of the abrasion test.
[0056] Decrease in break force was calculated by the quotient of
break strength at the end of the abrasion test and the initial
break strength. Abrasion rate was calculated as the quotient of the
decrease in the break force of the sample and the number of
abrasion test cycles. The abrasion rates for the LCP fiber alone
and the composite of the LCP fiber and ePTFE monofilament fiber
were 14.2 g/cycle and 5.0 g/cycle, respectively.
[0057] The test conditions and test results for this example as
well as those for all of the other examples (Examples 2 through 8)
appear in Tables 2 and 3, respectively.
Example 2A
[0058] A single ePTFE monofilament fiber was combined with a single
ultra high molecular weight polyethylene (UHMWPE) fiber
(Dyneema.RTM. fiber, DSM, Geleen, the Netherlands). Abrasion
testing was performed as previously described. The composite bundle
test results were compared to the results from the test of a single
UHMWPE fiber.
[0059] An ePTFE monofilament fiber as made and described in Example
1 was obtained. The two fiber types were combined by simply holding
them so that they were adjacent to one another. That is, no
twisting or other means of entangling was applied. The weight
percentages of these two fibers when combined were 79% UHMWPE and
21% ePTFE. The weights per unit length of the UHMWPE and the
composite bundle were 1581 d and 2006 d, respectively. The break
forces of the UHMWPE and the composite bundle were 50.80 kg and
51.67 kg, respectively. The tenacities of the UHMWPE and the
composite bundle were 32.1 g/d and 25.7 g/d, respectively. Adding
the ePTFE fiber to the UHMWPE fiber changed the weight per unit
length, break force, and tenacity by +27%, +2%, and -20%,
respectively.
[0060] A single UHMWPE fiber was tested for abrasion resistance
following the procedure described previously. Three complete wraps
were applied to the fiber. The test was conducted at 65 cycles per
minute, under 762 g tension (which corresponded to 1.5% of the
break force of the UHMWPE fiber).
[0061] The combination of the UHMWPE fiber and the ePTFE
monofilament fiber was also tested for abrasion resistance in the
same manner. Three complete wraps were applied to the combination
of the fibers. The test was conducted at 65 cycles per minute and
under 775 g tension (which corresponded to 1.5% of the break force
of the fiber combination).
[0062] The abrasion tests were run for 500 cycles, after which
point the test samples were tensile tested to determine their break
force. The composite bundle and the UHMWPE fiber exhibited 42.29 kg
and 10.90 kg break forces after abrasion, respectively. Adding the
ePTFE monofilament fiber to the UHMWPE fiber increased the
post-abrasion break force by 288%. Thus, adding the single ePTFE
fiber increased the break force by 2% prior to testing and resulted
in a 288% higher break force upon completion of the abrasion test.
The abrasion rates for the UHMWPE fiber alone and the composite of
the UHMWPE fiber and the ePTFE monofilament fiber were 79.8 g/cycle
and 18.8 g/cycle, respectively.
Example 2B
[0063] A combination of an ePTFE fiber and an UHMWPE fiber was
created and tested as described in Example 2a, except that in this
case the ePTFE fiber was a multifilament fiber. A 400 d ePTFE
monofilament fiber was towed using a pinwheel to create a
multifilament ePTFE fiber. The multifilament fiber possessed the
following properties: 405 d weight per unit length, 1.18 kg break
force, 2.90 g/d tenacity and 0.72 g/cc density.
[0064] One multifilament ePTFE fiber was combined with one UHMWPE
fiber as described in Example 2a. The properties and testing
results for the UHMWPE fiber are presented in Example 2a. The
composite bundle consisted of 80% UHMWPE by weight and 20% ePTFE by
weight.
[0065] The weight per unit length of the composite bundle was 1986
d. The break force of the composite bundle was 50.35 kg. The
tenacity of the composite bundle was 25.4 g/d. Adding the ePTFE
fiber to the UHMWPE fiber changed the weight per unit length, break
force, and tenacity by +26%, -1%, and -21%, respectively.
[0066] The combination of the UHMWPE fiber and the ePTFE
multifilament fiber was tested for abrasion resistance under 755 g
tension (which corresponded to 1.5% of the break force of the fiber
combination) using three full wraps and 65 cycles/min as in Example
2a. The abrasion tests were again run for 500 cycles. The break
force after abrasion for the composite ePTFE-UHMWPE bundle was
41.37 kg. Adding the ePTFE multifilament fiber to the UHMWPE fiber
increased the post-abrasion break force by 280%. Thus, adding the
single ePTFE fiber changed the break force by -1% prior to testing
and resulted in a 280% higher break force upon completion of the
abrasion test. The abrasion rate for the composite bundle was 18.0
g/cycle.
Example 3
[0067] An ePTFE monofilament fiber was combined with a twisted
para-aramid fiber (Kevlar.RTM. fiber, E.I. DuPont deNemours, Inc.,
Wilmington, Del.) and subjected to the abrasion test. The results
from this test were compared against the results from the test of a
single para-aramid fiber.
[0068] The ePTFE monofilament fiber was the same as described in
Example 1. The properties and testing results for the ePTFE
monofilament fiber are presented in Example 1. The para-aramid
fiber had a weight per unit length of 2027 d, a 40.36 kg break
force, and a tenacity of 19.9 g/d.
[0069] The two fiber types were combined as described in Example 1
yielding a composite bundle comprised of 83% para-aramid by weight
and 17% ePTFE monofilament by weight. The weight per unit length of
the composite bundle was 2452 d. The break force of the composite
bundle was 40.41 kg. The tenacity of the composite bundle was 16.7
g/d. Adding the single ePTFE fiber to the para-aramid changed the
weight per unit length, break force, and tenacity by +21%, +0%, and
-16%, respectively.
[0070] A single para-aramid fiber was tested for abrasion
resistance following the procedure described previously. It should
be noted that due to the twist of the para-aramid fiber, the wrap
direction was in the same direction as the inherent twist of the
para-aramid fiber, which in this case was the reverse of the other
examples. Three complete wraps were applied to the fiber. The test
was conducted at 65 cycles per minute, under 605 g tension (which
corresponded to 1.5% of the break force of the para-aramid
fiber).
[0071] The combination of the para-aramid fiber and the ePTFE
monofilament fiber was also tested for abrasion resistance in the
same manner. Three complete wraps were applied to the combination
of the fibers. The test was conducted at 65 cycles per minute and
under 606 g tension (which corresponded to 1.5% of the break force
of the fiber combination).
[0072] The abrasion tests were run for 400 cycles, after which
point the test samples were tensile tested to determine their break
force. The composite bundle and the para-aramid fiber exhibited
17.40 kg and 9.29 kg break forces after abrasion, respectively.
Adding the ePTFE monofilament fiber to the para-aramid fiber
increased the post-abrasion break force by 87%. Thus, adding the
single ePTFE fiber increased the break force by 0% prior to testing
and resulted in a 87% higher break force upon completion of the
abrasion test. The abrasion rates for the para-aramid fiber alone
and the composite of the para-aramid fiber and the ePTFE
monofilament fiber were 77.7 g/cycle and 57.5 g/cycle,
respectively.
Example 4
[0073] A single graphite-filled ePTFE fiber was combined with a
single ultra high molecular weight polyethylene (UHMWPE) fiber
(Dyneema.RTM. fiber) and subjected to the abrasion test. The
results from this test were compared against the results from the
test of a single UHMWPE fiber.
[0074] The graphite-filled ePTFE monofilament fiber was made in
accordance with the teachings of U.S. Pat. No. 5,262,234 to Minor,
et al. This fiber possessed the following properties: 475 d weight
per unit length, 0.98 kg break force, 2.07 g/d tenacity and 0.94
g/cc density. The properties and testing results for the UHMWPE
fiber are presented in Example 2a.
[0075] The two fiber types were combined in the same manner as in
Example 1. The weight percentages of these two fibers when combined
were 77% UHMWPE and 23% graphite-filled ePTFE. The weights per unit
length of the UHMWPE and the composite bundle were 1581 d and 2056
d, respectively. The break force of the composite bundle was 49.35
kg. The tenacity of the composite bundle was 24.0 g/d. Adding the
graphite-filled ePTFE fiber to the UHMWPE fiber changed the weight
per unit length, break force, and tenacity by +30%, -3%, and -25%,
respectively.
[0076] The combination of the UHMWPE fiber and the graphite-filled
ePTFE monofilament fiber was tested for abrasion resistance. Three
complete wraps were applied to the combination of the fibers. The
test was conducted at 65 cycles per minute and under 740 g tension
(which corresponded to 1.5% of the break force of the fiber
combination). The abrasion testing results for the UHMWPE fiber are
presented in Example 2a.
[0077] The abrasion tests were run for 500 cycles, after which
point the test samples were tensile tested to determine their break
force. The composite bundle exhibited a 36.73 kg break force after
abrasion. Adding the graphite-filled monofilament ePTFE to the
UHMWPE fiber increased the post-abrasion break force by 237%. Thus,
adding the ePTFE monofilament fiber changed the break force by -3%
prior to testing and resulted in a 237% higher break force upon
completion of the abrasion test. The abrasion rates for the single
UHMWPE fiber alone and the composite bundle of the single UHMWPE
fiber and the single graphite-filled ePTFE monofilament fiber were
79.8 g/cycle and 25.2 g/cycle, respectively.
Example 5
[0078] Three different fiber types, UHMWPE, LCP, and ePTFE
monofilament fibers, were combined to form a composite bundle.
These fibers have the same properties as reported in examples 1 and
2a. The number of strands and weight percent of each fiber type
were as follows: 1 and 40% for UHMWPE, 1 and 39% for LCP, and 2 and
21% for ePTFE monofilament.
[0079] Tensile and abrasion testing were performed for this
composite bundle as well as a composite bundle comprising one
strand each of the UHMWPE and LCP fibers. The weights per length,
break forces, and tenacities for the 2-fiber type and 3-fiber type
configurations were 3148 d and 3998 d, 73.64 kg and 75.09 kg, and
23.4 g/d and 18.8 g/d, respectively.
[0080] The abrasion test conditions were the same as previously
described except that the test was not terminated when a certain
number of cycles was reached, but rather once the sample failed and
three (not four) tests were conducted for each configuration. The
fibers were placed side-by-side in the abrasion tester in the
following manner: the LCP fiber, a PTFE fiber, the UHMWPE fiber, a
PTFE fiber with the LCP fiber positioned furthermost from the
operator and the PTFE fiber positioned closest to the operator.
Failure was defined as total breakage of the composite bundles. For
the abrasion test, 4 complete wraps were applied to the composite
bundle. The test was conducted at 65 cycles per minute. The applied
tension was 1105 g for the composite of UHMWPE and LCP fibers only
and was 1126 g for the composite of all three fiber types. The
tension in both tests corresponded to 1.5% of the break force of
the fiber combination.
[0081] The average cycles to failure was calculated from the three
abrasion test results. Failure occurred at 1263 cycles for the
composite bundle of UHMWPE and LCP fibers only and it occurred at
2761 cycles for the composite bundle of all three fiber types.
[0082] Adding the ePTFE monofilament fibers to the combination of
one UHMWPE fiber and one LCP fiber changed the weight per unit
length, break force, and tenacity by +27%, +2%, and -20%,
respectively. The addition of the ePTFE fibers increased the cycles
to failure by +119%.
Example 6
[0083] Two additional composite bundles were constructed using the
methods and fibers as described in Example 2a. These two composite
bundles were designed to have two different weight percentages of
the ePTFE monofilament and UHMWPE fiber components.
6a)
[0084] A single ePTFE fiber was combined with three UHMWPE fibers
and subjected to the abrasion test. The weight percentages of the
ePTFE fiber and the UHMWPE fibers were 8% and 92%, respectively.
The weights per unit length of the three UHMWPE fibers and of the
composite bundle were 4743 d and 5168 d, respectively. The break
forces of the three UHMWPE fibers and of the composite bundle were
124.44 kg and 120.63 kg, respectively. The tenacities of the three
UHMWPE fibers and of the composite bundle were 26.2 g/d and 23.3
g/d, respectively. Adding the ePTFE fiber to the three UHMWPE
fibers changed the weight per unit length, break force, and
tenacity by +9%, -3%, and -11% respectively.
[0085] For the abrasion test, 2 complete wraps were applied to the
test samples. The tests were conducted at 65 cycles per minute and
under 1867 g and 1810 g tension, respectively for the three UHMWPE
fibers alone and the composite bundle of three UHMWPE fibers and
single ePTFE fiber. (These tensions corresponded to 1.5% of the
break force of the test samples).
[0086] The abrasion tests were conducted for 600 cycles, after
which point the test samples were tensile tested to determine their
break force. The composite bundle and the three UHMWPE fibers
exhibited 99.07 kg and 23.90 kg break forces after abrasion,
respectively. Thus, adding the single ePTFE fiber to the three
UHMWPE fibers changed the break force by -3%% prior to testing and
resulted in a 314% higher break force upon completion of the
abrasion test. The abrasion rates for the composite of three UHMWPE
fibers without and with the single ePTFE monofilament fiber were
167.6 g/cycle and 35.9 g/cycle, respectively.
6b)
[0087] Five ePTFE fibers were combined with three UHMWPE fibers and
subjected to the abrasion test. The weight percentages of the ePTFE
fibers and the UHMWPE fibers were 31% and 69%, respectively. The
weights per unit length of the three UHMWPE fibers and of the
composite bundle were 4743 d and 6868 d, respectively. The break
forces of the three UHMWPE fibers and of the composite bundle were
124.44 kg and 122.53 kg, respectively. The tenacities of the three
UHMWPE fibers and of the composite bundle were 26.2 g/d and 19.0
g/d, respectively. Adding five ePTFE fibers to the three UHMWPE
fibers changed the weight per unit length, break force, and
tenacity by +45%, -2%, and -27%, respectively.
[0088] For the abrasion test, 2 complete wraps were applied to the
test samples. The tests were conducted at 65 cycles per minute and
under 1867 g and 1838 g tension, respectively for the three UHMXPE
fibers alone and the composite of three UHMWPE fibers and fives
ePTFE fibers. (These tensions corresponded to 1.5% of the break
force of the test samples.
[0089] The abrasion tests were conducted for 600 cycles, after
which point the test samples were tensile tested to determine their
break force. The composite bundle exhibited a 100.49 kg break force
after abrasion. Thus, adding the five ePTFE fibers changed the
break force by -2% prior to testing and, resulted in a 320% higher
break force upon completion of the abrasion test. The abrasion
rates for the composite of three UHMWPE fibers without and with the
five ePTFE monofilament fibers were 167.6 g/cycle and 36.7 g/cycle,
respectively.
Example 7
[0090] Another composite bundle was constructed using the methods
and the UHMWPE fiber as described in Example 2a. In this example a
lower density ePTFE monofilament fiber was used. This fiber was
produced in accordance with the teachings of U.S. Pat. No.
6,539,951 and possessed the following properties: 973 d weight per
unit length, 2.22 kg break force, 2.29 g/d tenacity and 0.51 g/cc
density.
[0091] Single fibers of both fiber types were combined as described
in Example 2. The weight percentages of these two fibers when
combined were 62% UHMWPE and 38% ePTFE. The weight per unit length
of the composite bundle was 2554 d. The break force of the
composite bundle was 49.26 kg. The tenacity of the composite bundle
was 19.3 g/d. Adding the single PTFE fiber to the UHMWPE fiber
changed the weight per unit length, break force, and tenacity by
+62%, -3%, and -40%, respectively.
[0092] The test method and results of abrasion testing a single
UHMWPE fiber were reported in Example 2a. The composite of the
UHMWPE fiber and the low density ePTFE monofilament fiber was also
tested for abrasion resistance in the same manner. Three complete
wraps were applied to the composite bundle. The test was conducted
at 65 cycles per minute and under 739 g tension (which corresponded
to 1.5% of the break force of the fiber combination).
[0093] The abrasion tests were run for 500 cycles, after which
point the test samples were tensile tested to determine their break
force. The composite bundle and the UHMWPE fiber exhibited 44.26 kg
and 10.9 kg break forces after abrasion, respectively. Thus, adding
the single ePTFE fiber changed the break force by -3% prior to
testing and resulted in a 306% higher break force upon completion
of the abrasion test. The abrasion rates for the UHMWPE fiber alone
and the composite bundle of the UHMWPE fiber and the low density
ePTFE monofilament fiber were 79.80 g/cycle and 10.00 g/cycle,
respectively.
Example 8
[0094] Another composite bundle was constructed using the methods
and the UHMWPE fiber as described in Example 2. In this Example,
matrix-spun PTFE multifilament fiber (E.I. DuPont deNemours, Inc.,
Wilmington, Del.) was used. This fiber possessed the following
properties: 407 d weight per unit length, 0.64 kg break force, 1.59
g/d tenacity and 1.07 g/cc density.
[0095] Single fibers of both fiber types were combined as described
in Example 2. The weight percentages of these two fibers when
combined were 80% UHMWPE and 20% PTFE. The weight per unit length
of the composite bundle was 1988 d. The break force of the
composite bundle was 49.51 kg. The tenacity of the composite bundle
was 24.9 g/d. Adding the single PTFE fiber to the UHMWPE fiber
changed the weight per unit length, break force, and tenacity by
+26%, -2%, and -22%, respectively.
[0096] The test method and results of abrasion testing a single
UHMWPE fiber were reported in Example 2a. The composite bundle of
the UHMWPE fiber and the PTFE multifilament fiber was also tested
for abrasion resistance in the same manner. Three complete wraps
were applied to the composite bundle. The test was conducted at 65
cycles per minute and under 743 g tension (which corresponded to
1.5% of the break force of the fiber combination).
[0097] The abrasion tests were run for 500 cycles, after which
point the test samples were tensile tested to determine their break
force. The composite bundle and the UHMWPE fiber exhibited 39.64 kg
and 10.9 kg break forces after abrasion, respectively. Thus, adding
the single PTFE fiber changed the break force by -2% prior to
testing and resulted in a 264% higher break force upon completion
of the abrasion test. The abrasion rates for the UHMWPE fiber alone
and the composite bundle of the UHMWPE fiber and the PTFE
multifilament fiber were 79.80 g/cycle and 19.74 g/cycle,
respectively.
Example 9
[0098] Another composite bundle was constructed using the methods
and the UHMWPE fiber as described in Example 2. In this Example, an
ETFE (ethylene-tetrafluoroethylene) multifilament fluoropolymer
fiber (available from E.I. DuPont deNemours, Inc., Wilmington,
Del.) was used. This fiber possessed the following properties: 417
d weight per unit length, 1.10 kg break force, 2.64 g/d tenacity
and 1.64 g/cc density.
[0099] Single fibers of both fiber types were combined as described
in Example 2. The weight percentages of these two fibers when
combined were 79% UHMWPE and 21% ETFE. The weight per unit length
of the composite bundle was 1998 d. The break force of the
composite bundle was 50.44 kg. The tenacity of the composite bundle
was 25.2 g/d. Adding the single ETFE fiber to the UHMWPE changed
the weight per unit length, break force, and tenacity by +26%, -1%,
and -21%, respectively.
[0100] The test method and results of abrasion testing a single
UHMWPE fiber were reported in Example 2a. The composite bundle of
the UHMWPE fiber and the ETFE multifilament fluoropolymer fiber was
also tested for abrasion resistance in the same manner. Three
complete wraps were applied to the composite bundle. The test was
conducted at 65 cycles per minute and under 757 g tension (which
corresponded to 1.5% of the break force of the fiber
combination).
[0101] The abrasion tests were run for 500 cycles, after which
point the abraded test samples were tensile tested to determine
their break force. The composite bundle and the UHMWPE fiber
exhibited 27.87 kg and 10.9 kg break forces after abrasion,
respectively. Thus, adding the single ETFE multifilament fiber
changed the break force by -1% prior to testing and resulted in a
156% higher break force upon completion of the abrasion test. The
abrasion rates for the UHMWPE fiber alone and the composite bundle
of the UHMWPE fiber and the ETFE multifilament fiber were 79.80
g/cycle and 45.14 g/cycle, respectively.
[0102] In summary, the above examples demonstrate certain
embodiments of the present invention, specifically: [0103] Examples
1-3 demonstrate the combination of a single ePTFE fiber with a
single fiber of each of the three major high strength fibers;
[0104] Example 2 also compares monofilament and multifilament ePTFE
fibers. [0105] Example 4 demonstrates the effect of combining a
graphite-filled ePTFE monofilament fiber with a single UHMWPE
fiber. [0106] Example 5 demonstrates the performance of a
three-fiber construction, as is used in making a rope; the abrasion
test was conducted until failure. [0107] Example 6 demonstrates the
effects of varying the amount of monofilament ePTFE fiber in a
two-fiber construction (varying the number of ePTFE fibers and
combining them with three UHMWPE fibers). [0108] Example 7
demonstrates the effect of using a lower density monofilament ePTFE
fiber [to compare with Examples 2a-b and Examples 6a-b]. [0109]
Example 8 demonstrates the effect of using a low tenacity,
non-expanded PTFE fiber with a UHMWPE fiber. [0110] Example 9
demonstrates the use of an alternative fluoropolymer.
[0111] These results are summarized in the following tables.
TABLE-US-00001 TABLE 1 Example 1 2a 2b 3 4 5 Fluoropolymer ePTFE
ePTFE ePTFE ePTFE ePTFE ePTFE Component fiber type mono- mono-
multi- mono- C-filled mono- mono- # of fibers 1 1 1 1 1 2
weight/length (d) 425 425 405 425 475 425 density (g/cc) 1.78 1.78
0.72 1.78 0.94 1.78 break force (kg) 2.29 2.29 1.18 2.29 0.98 2.29
tenacity (g/d) 5.38 5.38 2.9 5.38 2.07 5.38 weight percent (%) 21
21 20 17 23 21 Component 2 Type LCP UHMWPE UHMWPE para-aramid
UHMWPE LCP # of fibers 1 1 1 1 1 1 weight/length (d) 1567 1581 1581
2027 1581 1567 break force (kg) 34.55 50.8 50.8 40.36 50.8 34.55
tenacity (g/d) 22 32.1 32.1 19.9 32.1 22 weight percent (%) 79 79
80 83 77 39 Component 3 Type x x x x x UHMWPE # of fibers x x x x x
1 weight/length (d) x x x x x 1581 break force (kg) x x x x x 50.8
Tenacity (g/d) x x x x x 32.1 weight percent (%) x x x x x 40
Composite weight/length (d) 1992 2006 1986 2452 2056 3998 break
force (kg) 33.87 51.67 50.35 40.41 49.35 75.09 Tenacity (g/d) 17
25.7 25.4 16.7 24 18.8 Example 6a 6b 7 8 9 Fluoropolymer ePTFE
ePTFE ePTFE matrix-spun ETFE Component PTFE fiber type mono- mono-
mono- multi- multi- # of fibers 1 5 1 1 1 weight/length (d) 425 425
973 407 417 density (g/cc) 1.78 1.78 0.51 1.07 1.64 break force
(kg) 2.29 2.29 2.22 0.64 1.10 tenacity (g/d) 5.38 5.38 2.29 1.59
2.64 weight percent (%) 8 31 38 20 21 Component 2 Type UHMWPE
UHMWPE UHMWPE UHMWPE UHMWPE # of fibers 3 3 1 1 1 weight/length (d)
4743 4743 1581 1581 1581 break force (kg) 124.44 124.44 50.8 50.8
50.8 tenacity (g/d) 26.2 26.2 32.1 32.1 32.1 weight percent (%) 92
69 62 80 79 Component 3 Type x x x x x # of fibers x x x x x
weight/length (d) x x x x x break force (kg) x x x x x Tenacity
(g/d) x x x x x weight percent (%) x x x x x Composite
weight/length (d) 5168 6868 2554 1988 1998 break force (kg) 120.63
122.53 49.26 49.51 50.44 Tenacity (g/d) 23.3 19 19.3 24.9 25.2
[0112] TABLE-US-00002 TABLE 2 tension (g) rate (1.5% of the break
force) Exam- Composition Construction (cycles/ non-ePTFE number of
ple (weight %, fiber type) (number of fibers) min) component
composite twists cycles 1 21% monofilament ePTFE, 79% LCP 1 PTFE/1
LCP 100 518 508 5 1500 2a 21% monofilament ePTFE, 79% UHMWPE 1
PTFE/1 UHMWPE 65 762 775 3 500 2b 20% multifilament ePTFE, 80%
UHMWPE 1 PTFE/1 UHMWPE 65 762 755 3 500 3 17% monofilament ePTFE,
83% para-aramid 1 PTFE/1 para-aramid 65 605 606 3 400 4 23%
C-filled monofilament ePTFE, 77% 1 PTFE/1 UHMWPE 65 762 740 3 500
UHMWPE 5 21% monofilament ePTFE, 39% LCP, 40% 2 PTFE/1 LCP/ 65 1105
1126 4 to UHMWPE 1 UHMWPE failure 6a 8% monofilament ePTFE, 92%
UHMWPE 1 PTFE/3 UHMWPE 65 1867 1810 2 600 6b 31% monofilament
ePTFE, 69% UHMWPE 5 PTFE/3 UHMWPE 65 1867 1838 2 600 7 38% low
density monofilament ePTFE, 62% 1 PTFE/1 UHMWPE 65 762 739 3 500
UHMWPE 8 20% matrix-spun PTFE, 80% UHMWPE 1 PTFE/1 UHMWPE 65 762
743 3 500 9 21% ETFE, 79% UHMWPE 1 ETFE/1 UHMWPE 65 762 757 3
500
[0113] TABLE-US-00003 TABLE 3 Ratio of Break Break Strength
Strengths Ratio of after Abrasion after Abrasion Rate Abrasion Test
(kg) Abrasion Test (g/cycle) Rates Exam- Inventive Prior Art
(inventive:prior Inventive Prior Art (prior ple Composition (weight
%, fiber type) Article (no PTFE) art) Article (no PTFE)
art:inventive) 1 21% monofilament ePTFE, 79% LCP 26.38 13.21 2.00
5.00 14.20 2.84 2a 21% monofilament ePTFE, 79% UHMWPE 42.29 10.90
3.88 18.80 79.80 4.24 2b 20% multifilament ePTFE, 80% UHMWPE 41.37
10.90 3.80 18.00 79.80 4.43 3 17% monofilament ePTFE, 83% para-
17.40 9.29 1.87 57.50 77.70 1.35 aramid 4 23% C-filled monofilament
ePTFE, 77% 36.73 10.90 3.37 25.20 79.80 3.17 UHMWPE 5 21%
monofilament ePTFE, 39% LCP, 40% n/a n/a n/a n/a n/a n/a UHMWPE 6a
8% monofilament ePTFE, 92% UHMWPE 99.07 23.90 4.14 35.90 167.60
4.67 6b 31% monofilament ePTFE, 69% UHMWPE 100.49 23.90 4.20 36.70
167.60 4.57 7 38% monofilament ePTFE, 62% UHMWPE 44.26 10.90 4.06
10.00 79.80 7.98 8 20% matrix-spun PTFE, 80% UHMWPE 39.64 10.90
3.64 19.74 79.80 4.04 9 21% ETFE, 79% UHMWPE 27.87 10.90 2.56 45.14
79.80 1.77
While particular embodiments of the present invention have been
illustrated and described herein, the present invention should not
be limited to such illustrations and descriptions. It should be
apparent that changes and modifications may be incorporated and
embodied as part of the present invention within the scope of the
following claims. In particular, although primarily presented in
the exemplary embodiment of a rope for use in repeated stress
applications, the inventive composite bundles also have
applicability in other forms; for example, in belts, nets, slings,
cables, woven fabrics, nonwoven fabrics, and tubular textiles.
* * * * *