U.S. patent application number 15/718425 was filed with the patent office on 2018-03-29 for mixtures, articles having low coefficients of friction, methods of making these, and methods of using these.
The applicant listed for this patent is University of Florida Research Foundation, Inc.. Invention is credited to Jeffrey John Ewin, Brandon Alexander Krick, Angela Athena Pitenis, Wallace Gregory Sawyer.
Application Number | 20180086999 15/718425 |
Document ID | / |
Family ID | 61687181 |
Filed Date | 2018-03-29 |
United States Patent
Application |
20180086999 |
Kind Code |
A1 |
Sawyer; Wallace Gregory ; et
al. |
March 29, 2018 |
MIXTURES, ARTICLES HAVING LOW COEFFICIENTS OF FRICTION, METHODS OF
MAKING THESE, AND METHODS OF USING THESE
Abstract
The present disclosure provides for mixtures, methods for making
mixtures, articles, methods for making articles, and methods of
using articles. In an aspect, the articles have superior
tribological properties owing to combinations of
polytetrafluoroethylene and an irradiated fluoropolymer described
herein.
Inventors: |
Sawyer; Wallace Gregory;
(Gainesville, FL) ; Ewin; Jeffrey John;
(Gainesville, FL) ; Krick; Brandon Alexander;
(Gainesville, FL) ; Pitenis; Angela Athena;
(Gainesville, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
University of Florida Research Foundation, Inc. |
Gainesville |
FL |
US |
|
|
Family ID: |
61687181 |
Appl. No.: |
15/718425 |
Filed: |
September 28, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62400679 |
Sep 28, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10N 2030/06 20130101;
C10M 2217/0443 20130101; C10M 107/44 20130101; C10M 107/38
20130101; C10M 2205/0245 20130101; C10M 2213/062 20130101; C10M
2209/1075 20130101; C10N 2040/02 20130101; C10M 2205/0225 20130101;
C10N 2050/14 20200501; C10M 2213/0623 20130101; C10M 2221/0405
20130101; C10M 147/00 20130101; C10M 107/00 20130101; C10N 2050/08
20130101; C10M 107/32 20130101; C10M 169/041 20130101; C10M 107/04
20130101 |
International
Class: |
C10M 107/38 20060101
C10M107/38; C10M 107/44 20060101 C10M107/44; C10M 107/32 20060101
C10M107/32; C10M 107/04 20060101 C10M107/04 |
Claims
1. An article, comprising: a mixture derived from an irradiated
fluoropolymer and a matrix, wherein the matrix is chosen from
polyamide (PA), poly amide imide (PAI), polypropylene,
polyphenylene sulfide (PPS), polysulphone (PSU), polyether sulphone
(PES), a precursor thereof, a derivative thereof, a homopolymer
thereof, a monomer thereof, a copolymer thereof, a terpolymer
thereof, and a combination thereof, wherein the article has a
coefficient of friction of about 0.1 to 0.25, wherein the article
has a wear rate of about 1.times.10.sup.-8 mm.sup.3/Nm or less, and
wherein the irradiated fluoropolymer is a powder and the matrix is
a powder.
2. An article, comprising: a mixture derived from an irradiated
fluoropolymer and a matrix.
3. The article of claim 2, wherein the matrix is selected from the
group consisting of: polyetheretherketone (PEEK), polyimide (PI),
polyamide (PA), poly amide imide (PAI), polypropylene,
polyphenylene sulfide (PPS), polysulphone (PSU), polyether sulphone
(PES), a precursor thereof, a derivative thereof, a homopolymer
thereof, a monomer thereof, a copolymer thereof, a terpolymer
thereof, and a combination thereof.
4. The article of claim 2, wherein the irradiated fluoropolymer is
a powder and the matrix is a powder.
5. The article of claim 2, wherein the article has a coefficient of
friction of about 0.01 to 0.5.
6. The article of claim 2, wherein the article has a wear rate of
about 1.times.10.sup.-7 mm.sup.3/Nm or less.
7. The article of claim 2, wherein the article is a solid lubricant
or a coating.
8. The article of claim 2, wherein the mixture further comprises at
least one un-irradiated fluoropolymer.
9. The article of claim 8, wherein one of the irradiated
fluoropolymer includes at least one irradiated
polytetrafluoroethylene.
10. The article of claim 8, wherein one of the at least one
fluoropolymers is tetrafluoroethylene.
11. The article of claim 8, wherein the irradiated fluoropolymer is
comprised of 50 wt % or more fluorine.
12. The article of claim 1, wherein the article is selected from
the group consisting of: a bearing, a joint, a piston, a bushing, a
socket, a seal, and a gasket.
13. An article, comprising: a mixture derived from an irradiated
fluoropolymer and a matrix, wherein the article is selected from
the group consisting of: a bearing, a joint, a piston, a bushing, a
socket, a seal, and a gasket, wherein the article has a coefficient
of friction of about 0.1 to 0.25, wherein the article has a wear
rate of about 1.times.10.sup.-8 mm.sup.3/Nm or less.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to U.S.
Provisional Application Ser. No. 62/400,679, having the title
"MIXTURES, ARTICLES HAVING LOW COEFFICIENTS OF FRICTION, METHODS OF
MAKING THESE, AND METHODS OF THESE", filed on Sep. 28, 2016, the
disclosure of which is incorporated herein by reference in its
entirety.
BACKGROUND
[0002] Solid lubrication is necessary in many industries, where
friction and wear can cause the breakdown of parts and equipment.
Bearings, bushings, and other high cycle and high friction sliding
components can degrade over time. Solid lubricants made from
polyfluorotetraethylene (PTFE) are commonly used to reduce friction
in such parts. However, improvements in friction and wear
properties are needed to improve the life of these types of
components.
SUMMARY
[0003] Embodiments of the present disclosure provide for articles
comprising mixtures derived from an irradiated fluoropolymer and a
matrix and the like. In an aspect, the article, among others,
comprises a mixture derived from an irradiated fluoropolymer and a
matrix.
[0004] In another aspect, the article, among others, comprises: a
mixture derived from an irradiated fluoropolymer and a matrix,
wherein the matrix is chosen from polyamide (PA), poly amide imide
(PAI), polypropylene, polyphenylene sulfide (PPS), polysulphone
(PSU), polyether sulphone (PES), a precursor thereof, a derivative
thereof, a homopolymer thereof, a monomer thereof, a copolymer
thereof, a terpolymer thereof, and a combination thereof, wherein
the article has a coefficient of friction of about 0.1 to 0.25,
wherein the article has a wear rate of about 1.times.10.sup.-8
mm.sup.3/Nm or less, and wherein the irradiated fluoropolymer is a
powder and the matrix is a powder.
[0005] In another aspect, the article is a bearing, a joint, a
piston, a bushing, a socket, a seal, or a gasket, among others,
that comprises: a mixture derived from an irradiated fluoropolymer
and a matrix, wherein the article has a coefficient of friction of
about 0.1 to 0.25, wherein the article has a wear rate of about
1.times.10.sup.-8 mm.sup.3/Nm or less.
[0006] Other articles, methods, features, and advantages will be or
become apparent to one with skill in the art upon examination of
the following drawings and detailed description. It is intended
that all such additional articles, methods, features and advantages
be included within this description, be within the scope of the
present disclosure, and be protected by the accompanying
claims.
DETAILED DESCRIPTION
[0007] As used herein, UHMWPE refers to Ultra High Molecular Weight
Polyethylene.
[0008] As used herein, PEEK refers to
poly(aryl-ether-ether-ketone).
[0009] As used herein, PTFE refers to polytetrafluoroethylene.
[0010] Before the present disclosure is described in greater
detail, it is to be understood that this disclosure is not limited
to particular embodiments described, as such may, of course, vary.
It is also to be understood that the terminology used herein is for
the purpose of describing particular embodiments only, and is not
intended to be limiting, since the scope of the present disclosure
will be limited only by the appended claims.
[0011] Where a range of values is provided, it is understood that
each intervening value, to the tenth of the unit of the lower limit
(unless the context clearly dictates otherwise), between the upper
and lower limit of that range, and any other stated or intervening
value in that stated range, is encompassed within the disclosure.
The upper and lower limits of these smaller ranges may
independently be included in the smaller ranges and are also
encompassed within the disclosure, subject to any specifically
excluded limit in the stated range. Where the stated range includes
one or both of the limits, ranges excluding either or both of those
included limits are also included in the disclosure.
[0012] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this disclosure belongs.
Although any methods and materials similar or equivalent to those
described herein can also be used in the practice or testing of the
present disclosure, the preferred methods and materials are now
described.
[0013] As will be apparent to those of skill in the art upon
reading this disclosure, each of the individual embodiments
described and illustrated herein has discrete components and
features which may be readily separated from or combined with the
features of any of the other several embodiments without departing
from the scope or spirit of the present disclosure. Any recited
method can be carried out in the order of events recited or in any
other order that is logically possible.
[0014] Embodiments of the present disclosure will employ, unless
otherwise indicated, techniques of chemistry, tribology, and the
like, which are within the skill of the art. Such techniques are
explained fully in the literature.
[0015] The following examples are put forth so as to provide those
of ordinary skill in the art with a complete disclosure and
description of how to perform the methods and use the compositions
and compounds disclosed and claimed herein. Efforts have been made
to ensure accuracy with respect to numbers (e.g., amounts,
temperature, etc.), but some errors and deviations should be
accounted for. Unless indicated otherwise, parts are parts by
weight, temperature is in .degree. C., and pressure is in
atmosphere. Standard temperature and pressure are defined as
25.degree. C. and 1 atmosphere.
[0016] Before the embodiments of the present disclosure are
described in detail, it is to be understood that, unless otherwise
indicated, the present disclosure is not limited to particular
materials, reagents, reaction materials, manufacturing processes,
or the like, as such can vary. It is also to be understood that the
terminology used herein is for purposes of describing particular
embodiments only, and is not intended to be limiting. It is also
possible in the present disclosure that steps can be executed in
different sequence where this is logically possible.
[0017] It must be noted that, as used in the specification and the
appended claims, the singular forms "a," "an," and "the" include
plural referents unless the context clearly dictates otherwise.
Thus, for example, reference to "a support" includes a plurality of
supports. In this specification and in the claims that follow,
reference will be made to a number of terms that shall be defined
to have the following meanings unless a contrary intention is
apparent.
Discussion
[0018] Embodiments of the present disclosure provide for mixtures,
methods for making mixtures, articles, methods for making articles,
and methods of using articles. Embodiments of the present
disclosure relate to articles having superior tribological
properties.
[0019] In an aspect, the article can be used in many different
applications including, but not limited to, mechanical parts (e.g.,
bearing, joints, pistons, bushings, sockets, seals, gaskets, etc.),
structures having load bearing surfaces, sporting equipment,
machine parts and equipment, and the like.
[0020] In aspect, embodiments of the present disclosure can have a
low coefficient of friction (e.g., about 0.1 to 0.25) and/or very
low wear (e.g., about 1.times.10.sup.-7 mm.sup.3/Nm or less). In
addition, embodiments of the present disclosure provide for
articles that are resistant to chemicals, have a high strength, are
biocompatible, are water resistant, and/or have high thermal
resistance (e.g., withstand extreme temperatures).
[0021] In an exemplary embodiment, the mixture includes a
fluoropolymer (e.g., an irradiated fluoropolymer and/or
un-irradiated fluoropolymer) and a matrix. In an exemplary
embodiment, the mixture includes the fluoropolymer powder and one
or more matrix powders. In an exemplary embodiment, the mixture is
a powder. In an embodiment, the powder can be sieved through a
325-mesh that allows a maximum particle size of about 44
micrometers, with a mean particle diameter of about 1 to 15
micrometers or about 5 micrometers. Although some embodiments are
described as powders, an embodiment of the present disclosure
contemplates using non-powders as one or both of the irradiated
fluoropolymer and/or the matrix.
[0022] In an embodiment, the fluoropolymer (e.g., an irradiated
fluoropolymer and/or un-irradiated fluoropolymer) can be about 5 to
95 weight % of the mixture. In an embodiment, the matrix component
is about 5 to 95 weight % of the mixture.
[0023] Embodiments of the matrix can be made of polymers that have
one or more of the following characteristics: inert, corrosion
resistant, high melting point, high strength, or a combination
thereof. In particular, embodiments of the matrix can be made of
polymers such as, but not limited to, polyimide (PI),
polyetheretherketone (PEEK), polyamide (PA), poly amide imide
(PAI),polypropylene, polyphenylene sulfide (PPS), polysulphone
(PSU), polyether sulphone (PES), precursors thereof, derivatives
thereof, homopolymers thereof, monomers thereof, copolymers
thereof, terpolymers thereof, or combinations thereof. In an
embodiment, the matrix is PI. In an embodiment, the matrix is Nylon
(e.g., Nylon 6). In an embodiment, the filler is a powder.
[0024] In an embodiment, the irradiated fluoropolymer can be formed
by irradiating a fluoropolymer using an electron beam for an
appropriate time frame (e.g., seconds to minutes to hours, or
more). Although not intending to be bound by theory, the
irradiation breaks polymer bonds thereby fragmenting the polymer
into smaller portions and produces an increase in the number of
carboxylic acid groups. The increase in the concentration of
carboxylic acid groups causes the material to have a higher surface
energy, which increases the wettability of the material.
[0025] Embodiments of fluoropolymers disclosed below can refer to
either the irradiated fluoropolymer or un-irradiated fluoropolymer.
For each of the fluoropolymers mentioned herein, each can be
irradiated to form irradiated fluoropolymers. For clarity, the
fluoropolymers below are not referred to as irradiated
fluoropolymers, but irradiated fluoropolymers are intended to be
included as well. As a result, embodiments of the fluoropolymers
described below include both un-irradiated fluoropolymer and
irradiated fluoropolymer, where the fluoropolymers can be
irradiated to form the irradiated fluoropolymer.
[0026] In an embodiment, an individual fluoropolymer can be used
alone; mixtures or blends of two or more different kinds of
fluoropolymers can be used as well. Fluoropolymers useful in the
practice of this disclosure can be prepared from at least one
unsaturated fluorinated monomer (fluoromonomer). A fluoromonomer
suitable for use herein preferably contains about 35 wt % or more
fluorine, and preferably about 50 wt % or more fluorine, and can be
an olefinic monomer with at least one fluorine or fluoroalkyl group
or fluoroalkoxy group attached to a doubly-bonded carbon. In one
embodiment, a fluoromonomer suitable for use herein is
tetrafluoroethylene (TFE).
[0027] In one embodiment, the fluoropolymer can include
polytetrafluoroethylene (PTFE), which refers to (a) polymerized
tetrafluoroethylene by itself without any significant comonomer
present, i.e. a homopolymer of TFE, and (b) modified PTFE, which is
a copolymer of TFE with such small concentrations of comonomer that
the melting point of the resultant polymer is not substantially
reduced below that of PTFE (reduced, for example, by about 8% or
less, about 4% or less, about 2% or less, or about 1% or less).
Modified PTFE contains a small amount of comonomer modifier that
improves film forming capability during baking (fusing). Comonomers
useful for such purpose typically are those that introduce bulky
side groups into the molecule, and specific examples of such
monomers are described below. The concentration of such comonomer
is preferably less than 1 wt %, and more preferably less than 0.5
wt %, based on the total weight of the TFE and comonomer present in
the PTFE. A minimum amount of at least about 0.05 wt % comonomer is
preferably used to have a significant beneficial effect on
processability. The presence of the comonomer is believed to cause
a lowering of the average molecular weight.
[0028] In an embodiment, the mixture can be made by mixing the
fluoropolymer (e.g., irradiated fluoropolymer) and the matrix using
a fluid energy mill, in which high-speed rotation subjects the
mixture to intensive particulate collisions, producing increasingly
smaller particles. The fluoropolymer powder and the matrix powder
can be premixed and sent through the feed funnel of the mill to
create excellent particle dispersion. After grinding, the resulting
powder mixture can be formed into an article of manufacture having
a desired shape using techniques such as extruded film casting,
blown film, fiber spinning, stock shape extrusion, pipe and tubing
extrusion, thermoforming, compression molding, sintering, or the
like, accomplished using suitable forming equipment.
[0029] In other embodiments, materials produced by shaping
operations, including melt processing and forming, compression
molding or sintering, may be machined into final shapes or
dimensions. In still other implementations, the surfaces of the
parts may be finished by polishing or other operations.
[0030] In an embodiment, the mixture can be made by mixing the
fluoropolymer and the matrix in a variety of polar organic liquids,
which are useful in creating the particle dispersion and precursor
slurry from which the present composite powder material and
composite body are produced. Suitable liquids include, but are not
limited to, lower alcohols, such as methanol, ethanol, isopropanol
(IPA), n-butanol, and tent-butanol, or a combination thereof.
[0031] The fluoropolymer and the matrix can be added sequentially
(in either order) or concurrently to the alcohol, or premixed and
then added to the alcohol. In an embodiment, the mixture in the
alcohol can be mixed using sonication (e.g., exposure to a source
of ultrasonic energy produced by an ultrasonic horn). Preferably,
the intensity and time of the exposure is sufficient to cause the
particles to become substantially fully dispersed in the polar
organic liquid. Alternatively, the energy may be supplied by any
other suitable high-energy mixing technique, including without
limitation, high vortex or high shear mixing. After mixing, the
alcohol is allowed to evaporate off of the mixture for a period of
time (e.g., evaporated in a fume hood until dry). In an embodiment,
the dried mixture powder is compression molded and heated to a
temperature of about 300 to 450.degree. C. or about 370 to
390.degree. C. in an atmosphere of laboratory air for about 1 to 5
hours or about 3 hours. The compression mold can be designed to
produce a desired article. After the compression mold and heating
process, the article is cooled.
Tribological Testing
[0032] The wear resistance and coefficient of friction data shown
herein can be obtained using samples produced in accordance with
the following procedure or a similar procedure.
[0033] The samples are cut to size
(.about.0.25.times.0.25.times.0.5'') using a laboratory numerically
controlled milling machine. The machined samples are then polished
on a polishing wheel. The samples are left to dry in laboratory air
for 3-10 hours. The finished samples are then measured using
digital calipers and weighed; a density of each sample is
calculated from these measurements.
[0034] The sample is slid against a 304 stainless steel counter
sample for use with a .about.250 N normal load, 2 in/s sliding
velocity and 1 inch reciprocating stroke. The sliding tests are
interrupted periodically so the sample can be weighed. Prescribed
sliding cycles are 1000, then 10,000, then 100,000 then 1,000,000
to a total of 1,111,100 sliding cycles. A steady state wear rate is
determined as the wear rate once the material runs in. "Running in"
is a time towards the beginning of testing where a transfer film is
being developed and a slightly higher mass loss rate is observed.
It is observed that after the initial run-in, the wear rate is
relatively constant.
[0035] Wear measurements are made using two methods: a mass loss
method and a direct height loss measurement. For a mass loss
measurement, a sample is massed both before and after sliding
occurs. Based on the change in mass and the density of the
material, a volume loss and wear rate is obtained. A displacement
based measurement is complementary to the mass based measurement. A
linear variable differential transformer (LVDT) monitors a height
change of the sample, which can be equated to a volume and wear
rate measurements. It should also be noted that more ideal counter
materials and material finishes can generate lower wear rates.
[0036] Although not intending to be bound by theory, it appears
that the combination of the irradiated fluoropolymer and matrix
produces a synergistic effect on reducing the steady state wear
rate. Although not intending to be bound by theory, the superior
tribological properties of the articles may be the result of
reactions occurring between the components.
[0037] In an embodiment, articles made in accordance with the
foregoing process can be used in low friction applications. The
types of articles can vary greatly and include articles where
reduced friction is advantageous. In general, an embodiment of the
article can have one or more sliding surfaces or surfaces in
contact with another structures surface. The articles can have a
variety of shapes and cross sections. In an embodiment, the shape
of the article can be a simple three dimensional geometrical shape
(e.g., sphere, polyhedron, and the like) or a complex three
dimensional geometrical shape (e.g., irregular shapes). In general,
the article can have a cross-sectional shape including, but not
limited to, a polygon, a curved cross-section, irregular, and
combinations thereof.
[0038] Embodiments of the articles can be used in many structures,
parts, and components in the in the automotive, industrial,
aerospace industries, and sporting equipment industries, to name
but a few industries where articles having superior tribology
characteristics are advantageous. The article can be used in many
different applications including, but not limited to, mechanical
parts (e.g., a bearing, a joint, a piston, a bushing, a socket, a
seal, and a gasket), structures having load bearing surfaces,
sporting equipment, machine parts and equipment, and the like.
[0039] As mentioned above, the mixture can be formed into articles.
In an embodiment, the articles can be used in many structures,
parts, and components in the in the automotive, industrial,
aerospace industries, and sporting equipment industries, to name
but a few industries where articles having superior tribology
characteristics are advantageous. In an embodiment, the article can
be used in many different applications including, but not limited
to, mechanical parts (e.g., bearing, joins pistons, etc.),
structures having load bearing surfaces, sporting equipment,
machine parts and equipment, and the like. In particular, the
article can include a bearing, bushing, socket, and other high
cycle and high friction components.
[0040] In an embodiment including the irradiated fluoropolymer the
coefficient of friction can be about 0.01 to 0.5 and the steady
state wear rate can be about 1.times.10.sup.-7 mm.sup.3/Nm or less,
about 1.times.10.sup.-8 mm.sup.3/Nm or less, or about
1.times.10.sup.-7 mm.sup.3/Nm to 1.times.10.sup.-9 mm.sup.3/Nm.
[0041] In an embodiment including the un-irradiated fluoropolymer
the coefficient of friction can be about 0.1 to 0.25 and the wear
rate can be about 1.times.10.sup.-8 mm.sup.3/Nm or less, about
1.times.10.sup.-8 mm.sup.3/Nm or less, or about 1.times.10.sup.-8
mm.sup.3/Nm to about 1.times.10.sup.-9 mm.sup.3/Nm or less.
[0042] It should also be noted that the coefficient of friction and
wear characteristics of articles of the present disclosure can be
designed for a particular application. Thus, embodiments of the
present disclosure can provide articles that can satisfy many
different requirements for different industries and for particular
components.
EXAMPLES
[0043] Now having described the embodiments of the present
disclosure, in general, the following Examples describe some
additional embodiments of the present disclosure. While embodiments
of present disclosure are described in connection with the
following examples and the corresponding text and figures, there is
no intent to limit embodiments of the present disclosure to this
description. On the contrary, the intent is to cover all
alternatives, modifications, and equivalents included within the
spirit and scope of embodiments of the present disclosure.
Example 1
[0044] Example 1 refers to a mixture including PTFE and polyimide.
Details regarding Example 1 are herein, including a summary
describing the sample composition, counterface information, sample
dimensions, testing environment, testing parameters, initial wear
rate, steady state wear rate, total wear rate and average friction
coefficients.
SAMPLE: PTFE 7C and 20 weight percent, Polyimide_UF1 PTFE 7C-80
weight percent Counterface: 304L stainless steel lapped Density of
sample: 1.9 mg/mm.sup.3
Test Parameters
[0045] Environment: Lab Air
[0046] Reciprocating length: 25.4 mm
[0047] Sliding speed: 50.8 mm/s
[0048] Average Normal Force: 266.6 N
Results
[0049] Initial wear rate: 6.2.times.10.sup.-6 mm.sup.3 /Nm at 1000
cycles
[0050] Best wear rate: 1.1.times.10.sup.-8 mm.sup.3/Nm at 1000000
cycles
[0051] Total wear rate: 2.9.times.10.sup.-8 mm.sup.3/Nm at 1111000
cycles
[0052] Uncertainty in total wear rate: 1.1.times.10.sup.-9
mm.sup.3/Nm
[0053] Average friction coefficient: 0.20
[0054] Volume lost: 0.61 mm.sup.3
Example 2
[0055] Example 2 refers to a mixture including PTFE and nylon.
Details regarding Example 2 are herein, including a summary
describing the sample composition, counterface information, sample
dimensions, testing environment, testing parameters, initial wear
rate, steady state wear rate, total wear rate and average friction
coefficients.
SAMPLE: Nylon Shamrock PTFE
[0056] Nylon 6--80 weight percent, Shamrock PTFE--20 weight percent
(NanoFLON P51A Sub-micron PTFE) Counterface: 304 stainless steel
lapped Density of sample: 1.2 mg/mm.sup.3
Test Parameters
[0057] Environment: Lab Air
[0058] Reciprocating length: 25.4 mm
[0059] Sliding speed: 50.8 mm/s
[0060] Average Normal Force: 265.9 N
Results
[0061] Initial wear rate: 6.2.times.10.sup.-6mm.sup.3/Nm at 1000
cycles
[0062] Best wear rate: 1.3.times.10.sup.-7 mm.sup.3/Nm at 1000000
cycles
[0063] Total wear rate: 1.8.times.10.sup.-7 mm.sup.3/Nm at 1111000
cycles
[0064] Uncertainty in total wear rate: 2.1.times.10.sup.-9
mm.sup.3/Nm
[0065] Average friction coefficient: 0.25
[0066] Volume lost: 2.93 mm.sup.3
Example 3
[0067] Example 3 refers to a mixture including PEEK and PTFE.
Details regarding Example 3 are herein, including a summary
describing the sample composition, counterface information, sample
dimensions, testing environment, testing parameters, initial wear
rate, steady state wear rate, total wear rate and average friction
coefficients.
SAMPLE: PEEK PTFE 1 Sample 1
[0068] PEEK--80 weight percent, Shamrock PTFE--20 weight percent
(NanoFLON P51A Sub-micron PTFE) Counterface: 304 stainless steel
lapped Density of sample: 1.4 mg/mm.sup.3
Test Parameters
[0069] Environment: Lab Air
[0070] Reciprocating length: 25.4 mm
[0071] Sliding speed: 50.8 mm/s
[0072] Average Normal Force: 274.6 N
Results
[0073] Initial wear rate: 1.5.times.10.sup.-6 mm.sup.3/Nm at 1000
cycles
[0074] Best wear rate: 2.4.times.10.sup.-7 mm.sup.3/Nm at 1000000
cycles
[0075] Total wear rate: 2.5.times.10.sup.-7 mm.sup.3/Nm at 1111000
cycles
[0076] Uncertainty in total wear rate: 2.1.times.10.sup.-9
mm.sup.3/Nm
[0077] Average friction coefficient: 0.12
[0078] Volume lost: 3.96 mm.sup.3
Example 4
[0079] Example 4 refers to a mixture including UHMWPE and PTFE.
Details regarding Example 4 are herein, including a summary
describing the sample composition, counterface information, sample
dimensions, testing environment, testing parameters, initial wear
rate, steady state wear rate, total wear rate and average friction
coefficients. SAMPLE: UHMWPE PTFE 1
UHMWPE--80 weight percent, Shamrock PTFE--20 weight percent
Counterface: 304 stainless steel lapped Density of sample: 1
mg/mm.sup.3
Test Parameters
[0080] Environment: Lab Air
[0081] Reciprocating length: 25.4 mm
[0082] Sliding speed: 50.8 mm/s
[0083] Average Normal Force: 266.3 N
Results
[0084] Initial wear rate: 1.5.times.10.sup.-6 mm.sup.3/Nm at 1000
cycles
[0085] Best wear rate: 2.2.times.10.sup.-8 mm.sup.3/Nm at 100000
cycles
[0086] Total wear rate: 2.8.times.10.sup.-8 mm.sup.3/Nm at 1111000
cycles
[0087] Uncertainty in total wear rate: 2.0.times.10.sup.-9
mm.sup.3/Nm
[0088] Average friction coefficient: 0.16
[0089] Volume lost: 0.453 mm.sup.3
[0090] It should be noted that ratios, concentrations, amounts, and
other numerical data may be expressed herein in a range format. It
is to be understood that such a range format is used for
convenience and brevity, and thus, should be interpreted in a
flexible manner to include not only the numerical values explicitly
recited as the limits of the range, but also to include all the
individual numerical values or sub-ranges encompassed within that
range as if each numerical value and sub-range is explicitly
recited. To illustrate, a concentration range of "about 0.1% to
about 5%" should be interpreted to include not only the explicitly
recited concentration of about 0.1 wt % to about 5 wt %, but also
include individual concentrations (e.g., 1%, 2%, 3%, and 4%) and
the sub-ranges (e.g., 0.5%, 1.1%, 2.2%, 3.3%, and 4.4%) within the
indicated range. In an embodiment, the term "about" can include
traditional rounding according to measuring technique and the
numerical value. In addition, the phrase "about `x` to `y`"
includes "about `x` to about `y`".
[0091] Many variations and modifications may be made to the
above-described embodiments. All such modifications and variations
are intended to be included herein within the scope of this
disclosure and protected by the following claims.
* * * * *