U.S. patent application number 17/004590 was filed with the patent office on 2020-12-17 for abrasive article including shaped abrasive particles.
The applicant listed for this patent is SAINT-GOBAIN CERAMICS & PLASTICS, INC.. Invention is credited to Tves Boussant-Roux, Paul Braun, David F. Louapre, Alexandra MARAZANO, Cecile O. Mejean.
Application Number | 20200391354 17/004590 |
Document ID | / |
Family ID | 1000005051776 |
Filed Date | 2020-12-17 |
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United States Patent
Application |
20200391354 |
Kind Code |
A1 |
MARAZANO; Alexandra ; et
al. |
December 17, 2020 |
ABRASIVE ARTICLE INCLUDING SHAPED ABRASIVE PARTICLES
Abstract
Various shaped abrasive particles are disclosed. Each shaped
abrasive particle includes a body having at least one major surface
and another surface extending from the major surface.
Inventors: |
MARAZANO; Alexandra; (Saint
Paul les Romans, FR) ; Braun; Paul; (Providence,
RI) ; Boussant-Roux; Tves; (Avignon, FR) ;
Mejean; Cecile O.; (Acton, MA) ; Louapre; David
F.; (Paris, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAINT-GOBAIN CERAMICS & PLASTICS, INC. |
Worcester |
MA |
US |
|
|
Family ID: |
1000005051776 |
Appl. No.: |
17/004590 |
Filed: |
August 27, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15420673 |
Jan 31, 2017 |
10759024 |
|
|
17004590 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C04B 2235/94 20130101;
C04B 2235/6021 20130101; B24D 3/14 20130101; C04B 2235/3206
20130101; C04B 35/1115 20130101; B24D 99/00 20130101; C09K 3/1427
20130101; C04B 2235/606 20130101; C04B 2235/5427 20130101; B01J
2/26 20130101; C04B 2235/612 20130101 |
International
Class: |
B24D 99/00 20060101
B24D099/00; B24D 3/14 20060101 B24D003/14; C04B 35/111 20060101
C04B035/111; B01J 2/26 20060101 B01J002/26; C09K 3/14 20060101
C09K003/14 |
Claims
1. A method for forming shaped abrasive particles comprising:
forming a mixture comprising a precursor ceramic material;
extruding the mixture through a shaped opening to form an extrusion
having a cross-sectional shape corresponding to the shaped opening;
cutting the extrusion into green particles; and drying the green
particles to form shaped abrasive particles.
2. The method of claim 1, wherein drying comprises dropping the
green particles through a vertical air dryer to form precursor
shaped abrasive particles.
3. The method of claim 1, wherein the method further includes
collecting the shaped abrasive particles in a collection
receptacle.
4. The method of claim 2, wherein the vertical air dryer comprises
an updraft fan.
5. The method of claim 2, wherein the shaped abrasive particles
exit the dryer and land onto a conveyor belt.
6. The method of claim 1, wherein the shaped abrasive particles are
translated to a post-forming process including surface shaping,
curing, reacting, radiating, planarizing, calcining, sintering,
sieving, doping, drying, and a combination thereof.
7. The method of claim 1, wherein the shaped abrasive particles are
translated through an application zone wherein a dopant material is
applied.
8. The method of claim 1, wherein the method further includes
sintering the shaped abrasive particles.
9. The method of claim 1, wherein the shaped abrasive particles
have substantially the same arrangement of surfaces and edges
relative to each other.
10. The method of claim 1, wherein the shaped abrasive particles
have a two-dimensional shape, as viewed in a plane defined by the
length and width of the body, including a polygonal shape,
ellipsoidal shape, a numeral, a Greek alphabet character, a Latin
alphabet character, a Russian alphabet character, a complex shape
utilizing a combination of polygonal shapes and a combination
thereof.
11. The method of claim 1, wherein the precursor ceramic material
comprises an oxide, a nitride, a carbide, a boride, an oxycarbide,
an oxynitride, and a combination thereof.
12. The method of claim 1, wherein the precursor ceramic material
comprises alumina.
13. The method of claim 1, wherein the mixture has a viscosity of
at least about 2.times.103 Pa s.
14. The method of claim 1, wherein drying is conducted at a drying
temperature of not greater than about 300.degree. C.
15. The method of claim 1, wherein the shaped abrasive particles
comprises at least about 80 wt % alpha alumina.
16. The method of claim 1, wherein the shaped abrasive particles
consist essentially of alpha alumina.
17. The method of claim 1, wherein the shaped abrasive particles
are essentially free of a binder material.
18. The method of claim 1, wherein the shaped abrasive particles
are incorporated into a fixed abrasive article.
19. The method of claim 18, wherein the fixed abrasive article is
selected from a coated abrasive, bonded abrasive, or non-woven
abrasive.
20. The method of claim 10, wherein the shaped abrasive particles
are triangular.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation of and claims priority
under 35 U.S.C. .sctn. 120 to U.S. patent application Ser. No.
15/420,673, entitled "ABRASIVE ARTICLE INCLUDING SHAPED ABRASIVE
PARTICLES," by Alexandra MARAZANO et al., filed Jan. 31, 2017,
which is assigned to the current assignee hereof and incorporated
herein by reference in its entirety.
BACKGROUND
Field of the Disclosure
[0002] The following is directed to abrasive articles, and
particularly, abrasive articles including shaped abrasive
particles.
Description of the Related Art
[0003] Abrasive particles and abrasive articles made from abrasive
particles are useful for various material removal operations
including grinding, finishing, and polishing. Depending upon the
type of abrasive material, such abrasive particles can be useful in
shaping or grinding a wide variety of materials and surfaces in the
manufacturing of goods. Certain types of abrasive particles have
been formulated to date that have particular geometries, such as
triangular shaped abrasive particles and abrasive articles
incorporating such objects. See, for example, U.S. Pat. Nos.
5,201,916; 5,366,523; and 5,984,988.
[0004] Three basic technologies that have been employed to produce
abrasive particles having a specified shape are (1) fusion, (2)
sintering, and (3) chemical ceramic. In the fusion process,
abrasive particles can be shaped by a chill roll, the face of which
may or may not be engraved, a mold into which molten material is
poured, or a heat sink material immersed in an aluminum oxide melt.
See, for example, U.S. Pat. No. 3,377,660 (disclosing a process
including flowing molten abrasive material from a furnace onto a
cool rotating casting cylinder, rapidly solidifying the material to
form a thin semisolid curved sheet, densifying the semisolid
material with a pressure roll, and then partially fracturing the
strip of semisolid material by reversing its curvature by pulling
it away from the cylinder with a rapidly driven cooled
conveyor).
[0005] In the sintering process, abrasive particles can be formed
from refractory powders having a particle size of up to 10
micrometers in diameter. Binders can be added to the powders along
with a lubricant and a suitable solvent, e.g., water. The resulting
mixture, mixtures, or slurries can be shaped into platelets or rods
of various lengths and diameters. See, for example, U.S. Pat. No.
3,079,242 (disclosing a method of making abrasive particles from
calcined bauxite material including (1) reducing the material to a
fine powder, (2) compacting under affirmative pressure and forming
the fine particles of said powder into grain sized agglomerations,
and (3) sintering the agglomerations of particles at a temperature
below the fusion temperature of the bauxite to induce limited
recrystallization of the particles, whereby abrasive grains are
produced directly to size).
[0006] Chemical ceramic technology involves converting a colloidal
dispersion or hydrosol (sometimes called a sol), optionally in a
mixture, with solutions of other metal oxide precursors, into a gel
or any other physical state that restrains the mobility of the
components, drying, and firing to obtain a ceramic material. See,
for example, U.S. Pat. Nos. 4,744,802 and 4,848,041. Other relevant
disclosures on shaped abrasive particles and associated methods of
forming and abrasive articles incorporating such particles are
available at: http://www.abel-ip.com/publications/.
[0007] Still, there remains a need in the industry for improving
performance, life, and efficacy of abrasive particles, and the
abrasive articles that employ abrasive particles.
SUMMARY
[0008] According to a first aspect, a method for forming an
abrasive particle includes forming a green particle having a body
including at least one exterior corner having a first corner radius
and contacting at least a portion of the body to a hydrophobic
material and changing the first corner radius to a modified first
corner radius.
[0009] In another aspect, a shaped abrasive particle includes a
body including a first surface, a second surface, and a third
surface extending between the first surface and the second surface,
and wherein the body includes an exterior corner having a corner
radius within a range of at least 0.5 microns and not greater than
15 microns.
[0010] In another aspect, a method for forming shaped abrasive
particles includes creating a substrate including a sintered
ceramic material, and cutting the substrate to form a plurality of
shaped abrasive particles from the substrate.
[0011] In another aspect, a method of forming abrasive particles
includes depositing a free-standing droplet on a substrate; the
droplet comprising a mixture including a precursor ceramic material
and sintering the free-standing droplet to form a shaped abrasive
particle having an elliptical shape.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present disclosure may be better understood, and its
numerous features and advantages made apparent to those skilled in
the art by referencing the accompanying drawings.
[0013] FIG. 1 includes a system for forming a particulate material
in accordance with an embodiment.
[0014] FIG. 2 includes a flow chart of a method of forming a
particulate material in accordance with an embodiment.
[0015] FIG. 3 includes a flow chart of a method of forming a
particulate material in accordance with an embodiment.
[0016] FIG. 4 includes a flow chart of a method of forming a
particulate material in accordance with an embodiment.
[0017] FIG. 5 includes a flow chart of a method of forming a
particulate material in accordance with an embodiment.
[0018] FIG. 6 includes a flow chart of a method of forming a
particulate material in accordance with an embodiment.
[0019] FIG. 7 includes a flow chart of a method of forming a
particulate material in accordance with an embodiment.
[0020] FIG. 8 includes a perspective view of a shaped abrasive
particle in accordance with an embodiment.
[0021] FIG. 9 includes a top plan view of a shaped abrasive
particle in accordance with an embodiment.
[0022] FIG. 10 includes a front plan view of a shaped abrasive
particle in accordance with an embodiment.
[0023] FIG. 11 includes a side plan view of a shaped abrasive
particle in accordance with an embodiment.
[0024] FIG. 12 includes a side plan view of a shaped abrasive
particle in accordance with an embodiment.
[0025] FIG. 13 includes a top plan view of an intermediately formed
shaped abrasive particle in accordance with an embodiment.
[0026] FIG. 14 includes a perspective view of a shaped abrasive
particle in accordance with an embodiment.
[0027] FIG. 15 includes a front plan view of a shaped abrasive
particle in accordance with an embodiment.
[0028] FIG. 16 includes a top plan view of a shaped abrasive
particle in accordance with an embodiment.
[0029] FIG. 17 includes a detailed view of a shaped abrasive
particle in accordance with an embodiment take at Circle 17 in FIG.
15.
[0030] FIG. 18 includes a plan view of a shaped abrasive particle
in contact with a workpiece in accordance with an embodiment.
DETAILED DESCRIPTION
[0031] The following is directed to abrasive articles including
shaped abrasive particles. The methods herein may be utilized in
forming shaped abrasive particles and using abrasive articles
incorporating shaped abrasive particles. The shaped abrasive
particles may be utilized in various applications, including for
example fixed abrasive articles such as, coated abrasives, bonded
abrasives, non-woven abrasive materials and the like.
Alternatively, the shaped abrasive particles may be used in free
abrasives. Various other uses may be derived for the shaped
abrasive particles.
System and Methods for Making Shaped Abrasive Particles
[0032] Various systems and methods may be utilized to obtain shaped
abrasive particles. Some suitable processes used to fabricate the
shaped abrasive particles can include, but is not limited to,
depositing, printing (e.g., screen-printing), molding, pressing,
casting, sectioning, cutting, dicing, punching, drying, curing,
coating, extruding, rolling, embossing, patterning, and a
combination thereof.
[0033] Shaped abrasive particles are formed such that each particle
has substantially the same arrangement of surfaces and edges
relative to each other for shaped abrasive particles having the
same two-dimensional and three-dimensional shapes. As such, shaped
abrasive particles can have a high shape fidelity and consistency
in the arrangement of the surfaces and edges relative to other
shaped abrasive particles of the same group having the same
two-dimensional and three-dimensional shape. By contrast,
non-shaped abrasive particles can be formed through different
process and have different shape attributes. For example,
non-shaped abrasive particles are typically formed by a comminution
process, wherein a mass of material is formed and then crushed and
sieved to obtain abrasive particles of a certain size. However, a
non-shaped abrasive particle will have a generally random
arrangement of the surfaces and edges, and generally will lack any
recognizable two-dimensional or three dimensional shape in the
arrangement of the surfaces and edges around the body. Moreover,
non-shaped abrasive particles of the same group or batch generally
lack a consistent shape with respect to each other, such that the
surfaces and edges are randomly arranged when compared to each
other. Therefore, non-shaped grains or crushed grains have a
significantly lower shape fidelity compared to shaped abrasive
particles.
[0034] FIG. 1 includes an illustration of a system 100 for forming
a shaped abrasive particle in accordance with one, non-limiting
embodiment. As shown, the system 100 may include an extruder 102 in
which a piston 104 may move in order to apply a force 106 onto a
mixture 108 within the extruder 102. The resulting pressure of the
force 106 may extrude the mixture 108 through a die opening 110 in
the extruder 102. As the mixture 108 is forced through the die
opening 110, the mixture 108 can take on a cross-sectional shape of
the die opening. For example, if the die opening 110 is round, the
extruded mixture 108 can be round in cross-section. Further, if the
die opening 110 is triangular, the extruded mixture 108 can be
triangular in cross-section.
[0035] It can be appreciated that the die opening 110 can have
nearly any regular, or irregular, polygonal shape. For example, the
die opening 110 may be triangular with a square end, square with a
semi-circular end, or square with a saw tooth end. In other
embodiments, the die opening can include various shapes such as,
for example, polygons, ellipsoids, numerals, Greek alphabet
letters, Latin alphabet letters, Russian alphabet characters,
complex shapes including a combination of polygonal shapes, and a
combination thereof. In particular instances, the die opening 110
may have a polygonal shape such as a rectangle, a quadrilateral, a
pentagon, a hexagon, a heptagon, an octagon, a nonagon, a decagon,
and a combination thereof.
[0036] As illustrated in FIG. 1, the system 100 can further include
first rotating cutter 112 and a second rotating cutter 114. As
shown, the pair of rotating cutters 112, 114 may be placed below,
and on either side, of the extruder 102. Specifically, each of the
rotating cutters 112, 114 can be spaced an equal distance from an
extrusion axis 116 along which the mixture can be extruded. It will
be appreciated that other operations and tools may be used to
section the extrudate and form precursor shaped abrasive particles
(i.e., green particles) and the following is representative of one
particular process.
[0037] The first rotating cutter 112 can include a generally
cylindrical body 120 mounted on an axle 122. During operation, the
body 120 can rotate around the axle 122. The first rotating cutter
112 can also include a plurality of cutting blades 124 equally
spaced around an outer periphery 126 of the body 120 of the first
rotating cutter 112. As the body 120 of the first rotating cutter
112 rotates around the axle 122, the cutting blades 124 can also
rotate.
[0038] Similarly, the second rotating cutter 114 can include a
generally cylindrical body 130 mounted on an axle 132. During
operation, the body 130 can rotate around the axle 132. The second
rotating cutter 114 can also include a plurality of cutting blades
134 equally spaced around an outer periphery 136 of the body 130 of
the second rotating cutter 114. As the body 130 of the second
rotating cutter 114 rotates around the axle 132, the cutting blades
134 can also rotate.
[0039] As further shown in FIG. 1, the system 100 can include a
dryer 140 located along the extrusion axis 116 below the rotating
cutters 112, 114. Specifically, the dryer 140 can include an
interior cavity 142 through which the extrusion axis 116 passes.
The dryer 140 can include a fan 144 and the fan 144 can provide
heated air to the interior cavity 142 via a manifold 146 place at
or near the base of the dryer 140. The heated air can flow through
the dryer 140 and can dry green particles as they fall through the
dryer 140. In a particular aspect, heated air can flow upwards
through the dryer 140 in the direction indicated by arrows 148.
Alternatively or additionally, the dryer may use one or more
radiant heat sources.
[0040] FIG. 1 also indicates that the system 100 can include a
conveyor 150 that can be placed below the dryer 140. The conveyor
150 can include a drive wheel 152, a non-drive wheel 154, and a
conveyor belt 156 placed there around. As the drive wheel 152
rotates, the drive wheel 152 can move the conveyor belt 156 on the
drive wheel 152 and the non-drive wheel 154. The system 100 can
also include a collection basket 160 placed near the downstream end
of the conveyor 150.
[0041] The process of forming shaped abrasive particles using the
system 100 can be initiated by forming the mixture 108. The mixture
108 can include a ceramic material and a liquid. In particular, the
mixture 108 can be a gel formed of a ceramic powder material and a
liquid. In accordance with an embodiment, the gel can be formed of
the ceramic powder material as an integrated network of discrete
particles.
[0042] The mixture 108 may contain a certain content of solid
material, liquid material, and additives such that it has suitable
rheological characteristics for use with the process detailed
herein. That is, in certain instances, the mixture 108 can have a
certain viscosity, and more particularly, suitable rheological
characteristics that form a dimensionally stable phase of material
that can be formed through the process as noted herein. A
dimensionally stable phase of material is a material that can be
formed to have a particular shape and substantially maintain the
shape for at least a portion of the processing subsequent to
forming. In certain instances, the shape may be retained throughout
subsequent processing, such that the shape initially provided in
the forming process is present in the finally-formed object. It
will be appreciated that in some instances, the mixture 108 may not
be a shape-stable material, and the process may rely upon
solidification and stabilization of the mixture 108 by further
processing, such as drying.
[0043] The mixture 108 can be formed to have a particular content
of solid material, such as the ceramic powder material. For
example, in one embodiment, the mixture 108 can have a solids
content of at least about 25 wt %, such as at least about 35 wt %,
or even at least about 38 wt % or at least 40 wt % or at least 45
wt % or at least 50 wt % or at least 55 wt % for the total weight
of the mixture 108. Still, in at least one non-limiting embodiment,
the solids content of the mixture 108 can be not greater than about
75 wt %, such as not greater than about 70 wt %, not greater than
about 65 wt %, not greater than about 55 wt %, not greater than
about 45 wt %, or not greater than about 42 wt %. It will be
appreciated that the content of the solids materials in the mixture
108 can be within a range between any of the minimum and maximum
percentages noted above.
[0044] According to one embodiment, the ceramic powder material can
include an oxide, a nitride, a carbide, a boride, an oxycarbide, an
oxynitride, and a combination thereof. In particular instances, the
ceramic material can include alumina. More specifically, the
ceramic material may include a boehmite material, which may be a
precursor of alpha alumina. The term "boehmite" is generally used
herein to denote alumina hydrates including mineral boehmite,
typically being Al.sub.2O.sub.3.H.sub.2O and having a water content
on the order of 15%, as well as pseudoboehmite, having a water
content higher than 15%, such as 20-38% by weight. It is noted that
boehmite (including pseudoboehmite) has a particular and
identifiable crystal structure, and therefore a unique X-ray
diffraction pattern. As such, boehmite is distinguished from other
aluminous materials including other hydrated aluminas such as ATH
(aluminum trihydroxide), a common precursor material used herein
for the fabrication of boehmite particulate materials.
[0045] Furthermore, the mixture 108 can be formed to have a
particular content of liquid material. Some suitable liquids may
include water. In accordance with one embodiment, the mixture 108
can be formed to have a liquid content less than the solids content
of the mixture 108. In more particular instances, the mixture 108
can have a liquid content of at least about 25 wt % for the total
weight of the mixture 108. In other instances, the amount of liquid
within the mixture 108 can be greater, such as at least about 35 wt
%, at least about 45 wt %, at least about 50 wt %, or even at least
about 58 wt %. Still, in at least one non-limiting embodiment, the
liquid content of the mixture 108 can be not greater than about 75
wt %, such as not greater than about 70 wt %, not greater than
about 65 wt %, not greater than about 62 wt %, or even not greater
than about 60 wt %. It will be appreciated that the content of the
liquid in the mixture 108 can be within a range between any of the
minimum and maximum percentages noted above.
[0046] Furthermore, to facilitate processing and forming shaped
abrasive particles according to embodiments herein, the mixture 108
can have a particular storage modulus. For example, the mixture 108
can have a storage modulus of at least about 1.times.10.sup.4 Pa,
such as at least about 4.times.10.sup.4 Pa, or even at least about
5.times.10.sup.4 Pa. However, in at least one non-limiting
embodiment, the mixture 108 may have a storage modulus of not
greater than about 1.times.10.sup.7 Pa , such as not greater than
about 2.times.10.sup.6 Pa. It will be appreciated that the storage
modulus of the mixture 108 can be within a range between any of the
minimum and maximum values noted above.
[0047] The storage modulus can be measured via a parallel plate
system using ARES or AR-G2 rotational rheometers, with Peltier
plate temperature control systems. For testing, the mixture 108 can
be extruded within a gap between two plates that are set to be
approximately 8 mm apart from each other. After extruding the gel
into the gap, the distance between the two plates defining the gap
is reduced to 2 mm until the mixture 108 completely fills the gap
between the plates. After wiping away excess mixture 108, the gap
is decreased by 0.1 mm and the test is initiated. The test is an
oscillation strain sweep test conducted with instrument settings of
a strain range between 0.01% to 100%, at 6.28 rad/s (1 Hz), using
25-mm parallel plate and recording 10 points per decade. Within 1
hour after the test completes, the gap is lowered again by 0.1 mm
and the test is repeated. The test can be repeated at least 6
times. The first test may differ from the second and third tests.
Only the results from the second and third tests for each specimen
should be reported.
[0048] Furthermore, to facilitate processing and forming shaped
abrasive particles according to embodiments herein, the mixture 108
can have a particular viscosity. For example, the mixture 108 can
have a viscosity of at least about 2.times.10.sup.3 Pa s, such as
at least about 3.times.10.sup.3 Pa s, at least about
4.times.10.sup.3 Pa s, at least about 5.times.10.sup.3 Pa s, at
least about 6.times.10.sup.3 Pa s, at least about 8.times.10.sup.3
Pa s, at least about 10.times.10.sup.3 Pa s, at least about
20.times.10.sup.3 Pa s, at least about 30.times.10.sup.3 Pa s, at
least about 40.times.10.sup.3 Pa s, at least about
50.times.10.sup.3 Pa s, at least about 60.times.10.sup.3 Pa s, or
at least about 65.times.10.sup.3 Pa s. In at least one non-limiting
embodiment, the mixture 108 may have a viscosity of not greater
than about 100.times.10.sup.3 Pa s, such as not greater than about
95.times.10.sup.3 Pa s, not greater than about 90.times.10.sup.3 Pa
s, or even not greater than about 85.times.10.sup.3 Pa s. It will
be appreciated that the viscosity of the mixture 108 can be within
a range between any of the minimum and maximum values noted above.
The viscosity can be measured in the same manner as the storage
modulus as described above.
[0049] Moreover, the mixture 108 can be formed to have a particular
content of organic materials including, for example, organic
additives that can be distinct from the liquid to facilitate
processing and formation of shaped abrasive particles according to
the embodiments herein. Some suitable organic additives can include
stabilizers, binders such as fructose, sucrose, lactose, glucose,
UV curable resins, and the like.
[0050] Notably, the embodiments herein may utilize a mixture 108
that can be distinct from slurries used in conventional forming
operations. For example, the content of organic materials within
the mixture 108 and, in particular, any of the organic additives
noted above, may be a minor amount as compared to other components
within the mixture 108. In at least one embodiment, the mixture 108
can be formed to have not greater than about 30 wt % organic
material for the total weight of the mixture 108. In other
instances, the amount of organic materials may be less, such as not
greater than about 15 wt %, not greater than about 10 wt %, or even
not greater than about 5 wt %. Still, in at least one non-limiting
embodiment, the amount of organic materials within the mixture 108
can be at least about 0.01 wt %, such as at least about 0.5 wt %
for the total weight of the mixture 108. It will be appreciated
that the amount of organic materials in the mixture 108 can be
within a range between any of the minimum and maximum values noted
above.
[0051] Moreover, the mixture 108 can be formed to have a particular
content of acid or base, distinct from the liquid content, to
facilitate processing and formation of shaped abrasive particles
according to the embodiments herein. Some suitable acids or bases
can include nitric acid, sulfuric acid, citric acid, chloric acid,
tartaric acid, phosphoric acid, ammonium nitrate, and ammonium
citrate. According to one particular embodiment in which a nitric
acid additive is used, the mixture 108 can have a pH of less than
about 5, and more particularly, can have a pH within a range
between about 2 and about 4.
[0052] As shown in FIG. 1, the extruder 102 can be configured so
that as the piston 104 moves toward the die opening 110, the
mixture 108 can be extruded through the die opening 110 along the
extrusion axis 116. In accordance with an embodiment, a particular
pressure may be utilized during extrusion. For example, the
pressure can be at least about 10 kPa, such as at least about 500
kPa. Still, in at least one non-limiting embodiment, the pressure
utilized during extrusion can be not greater than about 6 MPa. It
will be appreciated that the pressure used to extrude the mixture
108 can be within a range between any of the minimum and maximum
values noted above. In particular instances, the consistency of the
pressure delivered by the piston 104 may facilitate improved
processing and formation of shaped abrasive particles. Notably,
controlled delivery of consistent pressure across the mixture 108
and across the width of the extruder 102 can facilitate improved
processing control and improved dimensional characteristics of the
shaped abrasive particles.
[0053] FIG. 1 shows that an extrudate 170 from the extruder 102 can
move along the extrusion axis 116 and pass through the rotating
cutters 112, 114. The blades 124, 134, on the rotating cutters 112,
114 can cut the extrudate 170 into green particles 172. In a
particular aspect, a release agent may be applied to the blades
124, 134 on the rotating cutters 112, 114 to prevent the green
particles 172 from sticking to the blades 124, 134 as they cut the
extrudate 170. Such a process can be optional and may not
necessarily be used prior to conducting the cutting process. A
suitable exemplary mold release agent can include an organic
material, such as one or more polymers (e.g., PTFE). In other
instances, an oil (synthetic or organic) may be applied as a mold
release agent to the surfaces of the blades 124, 134. One suitable
oil may be peanut oil. The mold release agent may be applied using
any suitable manner, including but not limited to, depositing,
spraying, printing, brushing, coating, and the like.
[0054] After the extrudate 170 is cut into the green particles 172,
the green particles 172 can fall through the dryer 140 where they
can be dried and exit the dryer 140 as precursor shaped abrasive
particles 174. Drying may include removal of a particular content
of certain materials from the green particles 172, including
volatiles, such as water or organic materials.
[0055] In accordance with an embodiment, the drying process can be
conducted at a drying temperature of not greater than about
300.degree. C., such as not greater than about 250.degree. C., not
greater than about 200.degree. C., not greater than about
150.degree. C., not greater than about 100.degree. C., not greater
than about 80.degree. C., not greater than about 60.degree. C., not
greater than about 40.degree. C., or even not greater than about
30.degree. C. Still, in one non-limiting embodiment, the drying
process may be conducted at a drying temperature of at least about
-20.degree. C., such as at least about -10.degree. C. at least
about 0.degree. C. at least about 5.degree. C. at least about
10.degree. C., or even at least about 20.degree. C. It will be
appreciated that the drying temperature may be within a range
between any of the minimum and maximum temperatures noted
above.
[0056] In certain instances, drying may be conducted for a
particular duration to facilitate the formation of shaped abrasive
particles according to embodiments herein. It can be appreciated
that increasing the length of the dryer, i.e., the distance through
which the green particles 172 fall through the dryer 140, can
increase the drying time 140. Further, increasing the speed of an
updraft fan may also increase the drying time as the updraft may
tend to blow the green particles 172 upwards into the dryer
140.
[0057] In a particular aspect, drying can be conducted for a
duration sufficient to remove some volatile materials from the
green particles and ensure proper formation of the shape abrasive
particles. For example, the drying time can be at least 10 seconds
or at least 60 seconds or at least 2 minutes or at least 5 minutes
or at least 10 minutes or at least 20 minutes or at least 30
minutes or at least 60 minutes. In still other instances, the
process of drying may be not greater than about 24 hours, such as
not greater than about 12 hours or not greater than about 6 hours
or not greater than about 3 hours or not greater than 1 hour. It
will be appreciated that the duration of drying can be within a
range between any of the minimum and maximum values noted above. It
will be appreciated that the drying duration can be altered
depending upon various factors, including the material, the average
particle size of the shaped abrasive particles, and the like.
[0058] Additionally, drying may be conducted at a particular
relative humidity to facilitate formation of shaped abrasive
particles according to the embodiments herein. For example, drying
may be conducted at a relative humidity of at least about 10%, such
as at least 20%, at least about 30%, at least about 40%, at least
about 50%, at least about 60%, such as at least about 62%, at least
about 64%, at least about 66%, at least about 68%, at least about
70%, at least about 72%, at least about 74%, at least about 76%, at
least about 78%, or even at least about 80%. In still other
non-limiting embodiments, drying may be conducted at a relative
humidity of not greater than about 90%, such as not greater than
about 88%, not greater than about 86%, not greater than about 84%,
not greater than about 82%, not greater than about 80%, not greater
than about 78%, not greater than about 76%, not greater than about
74%, not greater than about 72%, not greater than about 70%, not
greater than about 65%, not greater than about 60%, not greater
than about 55%, not greater than about 50%, not greater than about
45%, not greater than about 40%, not greater than about 35%, not
greater than about 30%, or even not greater than about 25%. It will
be appreciated that the relative humidity utilized during drying
can be within a range between any of the minimum and maximum
percentages noted above.
[0059] As the green particles 172 pass through and exit the dryer
140 they may be formed into precursor shaped abrasive particles
174. The precursor shaped abrasive particles 174 can land on the
conveyor belt 156 of the conveyor 150. The precursor shaped
abrasive particles 174 may then travel downstream on the conveyor
belt 156 for further processing. In one embodiment, the precursor
shaped abrasive particles 174 can exit the conveyor belt 150 into
the collection receptacle 160.
[0060] After completing the drying process, but before the
precursor shaped abrasive particles 174 are collected for further
use in an abrasive article, one or more post-forming processes may
be completed. Exemplary post-forming processes can include surface
shaping, curing, reacting, radiating, planarizing, calcining,
sintering, sieving, doping, drying, and a combination thereof. For
example, in one optional process, the precursor shaped abrasive
particles 174 may be translated by the conveyor 150 through an
optional shaping zone, wherein at least one exterior surface of the
precursor shaped abrasive particles 174 may be further shaped.
[0061] In still another embodiment, the precursor shaped abrasive
particles 174 may be translated through an optional application
zone, wherein a dopant material can be applied. In particular
instances, the process of applying a dopant material can include
selective placement of the dopant material on at least one exterior
surface of the precursor shaped abrasive particles 174. In an
optional process, the precursor shaped abrasive particles 174 may
be treated with one or more acid or base materials. Treatment may
occur post-calcination and may affect a distribution of dopant
material within the shaped abrasive particle. In alternative
instances, an impregnation process may be used instead of doping,
where impregnation utilizes an additive introduced to the precursor
particles after calcination. Utilization of doping or impregnation
may affect distribution of the dopant material within the final
shaped abrasive particle which may also facilitate increased
performance of the shaped abrasive particle.
[0062] The dopant material may be applied utilizing various methods
including for example, spraying, dipping, depositing, impregnating,
transferring, punching, cutting, pressing, crushing, and any
combination thereof. In accordance with an embodiment, applying a
dopant material can include the application of a particular
material, such as a precursor. In certain instances, the precursor
can be a salt, such as a metal salt, that includes a dopant
material to be incorporated into the finally-formed shaped abrasive
particles. For example, the metal salt can include an element or
compound that is the precursor to the dopant material. It will be
appreciated that the salt material may be in liquid form, such as
in a dispersion comprising the salt and liquid carrier. The salt
may include nitrogen, and more particularly, can include a nitrate.
In other embodiments, the salt can be a chloride, sulfate,
phosphate, and a combination thereof. In one embodiment, the salt
can include a metal nitrate, and more particularly, consist
essentially of a metal nitrate. In one embodiment, the dopant
material can include an element or compound such as an alkali
element, alkaline earth element, rare earth element, hafnium,
zirconium, niobium, tantalum, molybdenum, vanadium, or a
combination thereof. In one particular embodiment, the dopant
material includes an element or compound including an element such
as lithium, sodium, potassium, magnesium, calcium, strontium,
barium, scandium, yttrium, lanthanum, cesium, praseodymium,
niobium, hafnium, zirconium, tantalum, molybdenum, vanadium,
chromium, cobalt, iron, germanium, manganese, nickel, titanium,
zinc, and a combination thereof.
[0063] The forming process may further include a sintering process.
For certain embodiments herein, sintering can be conducted after
the precursor shaped abrasive particles 174 are dried in the dryer
140. Sintering of the precursor shaped abrasive particles 174 may
be utilized to densify the precursor shaped abrasive particles 174
and create the finally-formed shaped abrasive particles. In a
particular instance, the sintering process can facilitate the
formation of a high-temperature phase of the ceramic material. For
example, in one embodiment, the precursor shaped abrasive particles
174 may be sintered such that a high-temperature phase of alumina,
such as alpha alumina, is formed. In one instance, a shaped
abrasive particle can comprise at least about 80 wt % alpha
alumina, such as at least 90 wt % alpha alumina for the total
weight of the particle. In other instances, the content of alpha
alumina may be greater such that the shaped abrasive particle may
consist essentially of alpha alumina.
[0064] The body of each of the precursor shaped abrasive particles
174 can have a particular two-dimensional shape. For example, the
body can have a two-dimensional shape, as viewed in a plane defined
by the length and width of the body, and can have a shape including
a polygonal shape, ellipsoidal shape, a numeral, a Greek alphabet
character, a Latin alphabet character, a Russian alphabet
character, a complex shape utilizing a combination of polygonal
shapes and a combination thereof. Particular polygonal shapes
include rectangular, trapezoidal, pentagonal, hexagonal,
heptagonal, octagonal, nonagonal, decagonal, and any combination
thereof. In another instance, the finally-formed shaped abrasive
particles 174 can have a body having a two-dimensional shape such
as an irregular quadrilateral, an irregular rectangle, an irregular
trapezoid, an irregular pentagon, an irregular hexagon, an
irregular heptagon, an irregular octagon, an irregular nonagon, an
irregular decagon, and a combination thereof. An irregular
polygonal shape is one where at least one of the sides defining the
polygonal shape is different in dimension (e.g., length) with
respect to another side. As illustrated in other embodiments
herein, the two-dimensional shape of certain shaped abrasive
particles 174 can have a particular number of exterior points or
external corners. For example, the body of the precursor shaped
abrasive particles 174 can have a two-dimensional polygonal shape
as viewed in a plane defined by a length and width, wherein the
body comprises a two-dimensional shape having at least 4 exterior
points (e.g., a quadrilateral), at least 5 exterior points (e.g., a
pentagon), at least 6 exterior points (e.g., a hexagon), at least 7
exterior points (e.g., a heptagon), at least 8 exterior points
(e.g., an octagon), at least 9 exterior points (e.g., a nonagon),
and the like.
[0065] Referring to FIG. 2, a method of forming shaped abrasive
particles in accordance with one, non-limiting embodiment is
illustrated and is generally designated 200. Notably, the process
illustrated in FIG. 2 includes the process of using the system as
described in accordance with FIG. 1. At step 202, the method can
include forming a mixture that includes a precursor ceramic
material. In a particular aspect, the mixture can be similar to the
mixture 108 described above in conjunction with FIG. 1.
[0066] Proceeding to step 204, the method 200 can include extruding
the mixture through a shaped opening to form an extrusion having a
cross-sectional shape corresponding to the shaped opening. In a
particular aspect, the mixture may be extruded through an extruder
similar to the extruder 102 described above. At step 206, the
method 200 can include cutting the extrusion into green particles.
The extrusion, or extrudate, may be cut into green particles as it
passes through one or more rotating cutters, e.g., as described
above in conjunction with FIG. 1. At step 208, method 200 can
include drying the green particles to form shaped abrasive
particles. The green particles may be dried by dropping them
through a vertical air dryer, e.g., through a dryer that is similar
to the dryer 140 depicted in FIG. 1. In another aspect, the green
particles may be dried using other methods well known in the art.
Finally, at step 210, the method 200 can include collecting the
shaped abrasive particles.
[0067] FIG. 3 illustrates a flowchart of a method, generally
designated 300, of forming shaped abrasive particles in accordance
with one, non-limiting embodiment. The process described in FIG. 3
is different than the process described in the flow chart of FIG. 2
and may use a different system as compared to the system described
in FIG. 1. As depicted, at step 302, the method 300 can include
forming a green particle that has a body that includes at least one
exterior corner that has a first corner radius. In a particular
aspect, the green particle may be formed using an extrusion
process, a molding process, a screen printing process, a stamping
process, or some other process known in the art. Specifically, the
green particle may be formed using a screen printing process.
[0068] Further, in a particular aspect, the green particle may be
formed from a mixture that is similar to the mixture 108 described
above in conjunction with FIG. 1. Moving to step 304, the method
300 can include contacting at least a portion of the body to a
modifying tool. The modifying tool may be made of a particular
material and have particular surface properties with respect to the
mixture, such that the modifying tool is configured to change the
shape of the body after forming but before significant drying of
the body. For example, in one embodiment the modifying tool can
include a hydrophobic material. In yet another embodiment, the
modifying tool can include a hydrophilic material. The use of a
tool having a particular material (e.g., a hydrophilic material or
a hydrophobic material) may facilitate modification of the shape of
the body post-forming by encouraging the mixture to react in a
particular manner when placed in contact with the material of the
tool. For example, in one embodiment, the modification tool is used
to modify the shape of the mixture making the body, and in
particular, it is envisioned that the modification tool can be used
to change the corner sharpness and edge sharpness of the body
post-forming.
[0069] The modification tool may be a surface with select regions
of hydrophobic and/or hydrophilic material such that when the
precursor shaped abrasive particles are placed in contact with the
modification tool, the mixture making up the bodies of the
precursor shaped abrasive particles is encouraged to move in
accordance with the regions defined by the hydrophobic and/or
hydrophilic material. In one particular aspect, the modification
tool is formed to include a pattern of hydrophilic portions made of
a hydrophilic material and such hydrophilic portions are surrounded
by hydrophobic portions. The precursor abrasive particles are
placed on the hydrophilic portions and the mixture of the body is
encouraged to flow and correspond to the general shape of the
hydrophilic portions and thus the body of the precursor shaped
abrasive particle is modified post formation. It is envisioned that
such a method may be used to create precursor shaped abrasive
particles with sharper edges and corners than is currently
available via conventional molding and printing operations. It will
be appreciated that the ability of the mixture to move in relation
to the modification tool may depend in part upon the rheological
properties of the mixture, including for example viscosity. It may
be feasible to use a mixture having a low viscosity and/or low
storage modulus to allow for some flow of the mixture in response
to the modification tool.
[0070] The production tool may be a surface, a patterned surface
with protrusions and depressions, a mold having cavities as blind
holes and/or apertures, a screen, or any combination thereof.
[0071] For example, referring again to FIG. 3, at step 306, the
method 300 can include changing the first corner radius to a
modified first corner radius. In a particular aspect, the modified
first corner radius can be less than the first corner radius.
Further, the step of contacting a portion of the body to a
hydrophobic material can include placing the green particle in
contact with a hydrophobic surface and contacting the green
particle with the hydrophobic surface can reduce the first corner
radius. For example, the modified first corner radius can be less
than 50 microns or less than 30 microns or less than 20 microns or
less than 10 microns or less than 5 microns or less than 1
micron.
[0072] Thereafter, the method 300 can include sintering the green
particle to create a shaped abrasive particle at step 308.
Sintering may be conducted according to those methods disclosed
herein or as known in the art. It will be understood that the
process of FIG. 3 is disclosed as being suitable for modification
of the shape of precursor shaped abrasive particles post-formation,
but such a modification tool can be used in other instances. For
example, such a modification tool may be suitable for use on a
sheet of mixture, wherein the precursor abrasive particles have not
been formed. In certain embodiments.it is contemplated that the
modification tool can be both a shaping tool and a modification
tool, such that the shaping and modification can occur
simultaneously. Such shaping tools may be formed using any suitable
technique, including for example, but not limited to a
photolithography process for forming exact and discrete regions on
a surface.
[0073] Referring now to FIG. 4, a method of forming shaped abrasive
particles in accordance with one, non-limiting embodiment is
illustrated and is generally designated 400. At step 402, the
method 400 can include creating a substrate comprising a sintered
ceramic material. Then, at step 404, the method 400 can include
cutting the substrate to form a plurality of shaped abrasive
particles from the substrate.
[0074] In particular embodiment, the step of creating a substrate
comprising a sintered ceramic material can include creating a
mixture comprising a precursor ceramic material, forming the
mixture into a green body, and sintering the green body to form a
sintered ceramic material in the form of the substrate. In a
particular aspect, the mixture can be similar to the mixture 108
described above in conjunction with FIG. 1. In another aspect, the
substrate can be in the form a polyhedral shape. Further, the
substrate can be in the form of a cuboid.
[0075] In a particular aspect, the step of cutting the substrate
can be performed with one or more mechanical devices, such as a
blade (e.g., a 1A8 abrasive dicing blade). In another aspect,
cutting the substrate can be performed using a bonded abrasive thin
wheel that includes superabrasive particles contained in a bond
matrix. In still another embodiment, a milling operation may be
used to cut one or more shaped abrasive particles from the sintered
substrate.
[0076] Unlike other conventional processes, the process of cutting
the substrate and forming shaped abrasive particles is completed on
a sintered substrate material. In one embodiment, the sintered
ceramic material can include alumina. In particular, the sintered
ceramic material can include alpha alumina. In another aspect, the
step of cutting the substrate can be accomplished using a computer
controlled cutting operation that is configured to create shaped
abrasive particles that have complex three-dimensional shapes.
Moreover, each of the shaped abrasive particles of the plurality of
shaped abrasive particles can have substantially the same shape
with respect to each other. However, in another aspect, at least a
portion of the shaped abrasive particles of the plurality of shaped
abrasive particles have a different two-dimensional shape with
respect each other.
[0077] FIG. 5 depicts a flowchart of a method of forming shaped
abrasive particles in accordance with one, non-limiting embodiment.
The method is generally designated 500. As illustrated, at step
502, the method 500 can include forming a mixture that includes a
precursor ceramic material. In a particular aspect, the mixture can
be similar to the mixture 108 described above in conjunction with
FIG. 1. At step 504, the method 500 can include forming the mixture
into a green body. In a particular aspect, the green body may be
formed using an extrusion process, a molding process, a screen
printing process, a stamping process, or some other process known
in the art.
[0078] Moving to step 506, the method 500 can include sintering the
green body to form a sintered ceramic material in the form of a
substrate. The green body may be sintered as described above or
using another sintering process well known in the art. At step 508,
the method 500 can include cutting the substrate to form a
plurality of shaped abrasive particles from the substrate.
[0079] Referring to FIG. 6, a method of forming shaped abrasive
particles in accordance with one, non-limiting embodiment is
illustrated and is generally designated 600. At step 602, the
method 600 can include forming a mixture that includes a precursor
ceramic material. In a particular aspect, the mixture can be
similar to the mixture 108 described above in conjunction with FIG.
1. At step 604, the method 600 can include selecting a material for
a substrate relative to the material of the mixture to control a
contact angle of the mixture on the substrate. Further, at step
606, the method 600 can include depositing a free-standing droplet
of the mixture on the substrate. At step 608, the method 600 can
include further processing the free-standing droplet to form a
shaped abrasive particle that has an upper surface having an
elliptical, or curvilinear, shape. Further processing can include
any post-formation processes described in any of the embodiments
herein, including but not limited to, drying, sintering, and the
like. Finally, at step 610, the method 600 can include removing the
shaped abrasive particle from the substrate.
[0080] In a particular aspect, the step of depositing a
free-standing droplet of the mixture on the substrate can include
dropping a plurality of drops of the mixture from a deposition
assembly. The deposition assembly can have a selectable deposition
volume and is configured to control the volume of mixture that is
deposited for each free-standing droplet. For example, in at least
one embodiment, the process can include using a selective printing
process to selectively deposit droplets of a known volume, size and
at specified locations on the substrate. Further, the free-standing
droplet can include a contact angle with the substrate of less than
50 degrees or less than 40 degrees or less than 30 degrees. In
another aspect, the contact angle can be at least 1 degree or at
least 2 degrees or at least 5 degrees or at least 8 degrees or at
least 10 degrees.
[0081] The process described in conjunction with FIG. 6 can be a
continuous process and the substrate can be translated under a
deposition assembly that continuously deposits a plurality of
free-standing droplets onto the substrate as it is translated under
the deposition assembly. The method can further include controlling
an average particle size of the shaped abrasive particle based on
the volume of material deposited in the free-standing droplet. In
another aspect, the method can include controlling an average
particle size of the shaped abrasive particle based on the material
of the substrate and the material of the mixture. Moreover, it is
envisioned that the process of FIG. 6 can be combined with the
process described in FIG. 3, wherein the droplet may be placed on a
modification tool, such that the contact angle and the corner
sharpness can be controlled by controlled placement of the mixture
onto a modification tool having at least one of hydrophilic
portions and/or hydrophobic portions.
[0082] FIG. 7 includes a flowchart of a method, generally
designated 700, of forming shaped abrasive particles in accordance
with one, non-limiting embodiment. As depicted in FIG. 7, at step
702, the method 700 can include forming a mixture that includes a
precursor ceramic material. In a particular aspect, the mixture can
be similar to the mixture 108 described above in conjunction with
FIG. 1. At step 704, the method 700 can include depositing the
mixture on a plate. Moreover, at step 706, the method 700 can
include directing a beam of energy at the mixture. In one aspect,
the beam of energy can be in the form a laser beam. At step 708,
the method 700 can include creating localized areas of dryness in
the mixture create shaped abrasive particles. Then, at step 710,
the method 700 can include separating the shaped abrasive particles
from the mixture.
Shaped Abrasive Particles
[0083] FIG. 8 through FIG. 12 illustrate various aspects of a
shaped abrasive particle 800 that can be made using one or more of
the methods described herein. For example, in at least one
embodiment, the shaped abrasive particle 800 can be made using the
method illustrated in FIG. 3.
[0084] FIG. 8 includes a perspective view of the shaped abrasive
particle 800. FIG. 9 is a top plan view of the shaped abrasive
particle 800. The bottom plan view is the same as the top plan view
shown in FIG. 9. FIG. 10 is a front plan view of the shaped
abrasive particle 800. The rear plan view of the shaped abrasive
particle 800 is the same as the front plan view depicted in FIG.
10. FIG. 11 is a first side plan view of the shaped abrasive
particle 800 and FIG. 12 is a second side plan view of the shaped
abrasive particle 800.
[0085] As illustrated, the shaped abrasive particle 800 can include
a body 802 that can be generally shaped like an arrowhead. The body
802 can include a first major surface 804 and a second major
surface 806. A side surface 808 can extend between the first major
surface 804 and the second major surface 806. The side surface 808
can include a first portion 810, a second portion 812, and a third
portion 814. The first portion 810 can form an angle 814 with
respect to the second portion 812. The angle 814 can be less than
or equal to 75.degree., such as less than or equal to 60.degree.,
less than or equal to 50.degree., less than or equal to 40.degree.,
or less than or equal to 35.degree.. In another aspect, the angle
814 can be greater than or equal to 15.degree., such as greater
than or equal to 20.degree., greater than or equal to 25.degree.,
or greater than or equal to 30.degree..
[0086] FIG. 9 shows that the third portion 814 of the side surface
808 can extend between the first portion 810 and the second portion
812 of the side surface 808. The third portion 814 can be generally
elliptical in shape. As shown in FIG. 9, the third portion 814 of
the side surface 808 can meet the first portion 810 of the side
surface 808 to form a first corner 816. The third portion 814 of
the side surface 808 can also meet the second portion 812 of the
side surface 808 to form a second corner 818.
[0087] In a particular aspect, the shaped abrasive particle 800 can
be formed using the method described in conjunction with FIG. 3. As
such, before the final shaped abrasive particle 800 is formed, a
green particle is formed. FIG. 13 illustrates a green particle 1300
that is an intermediate shaped abrasive particle. The green
particle 1300 can include a body 1302 having a first corner 1304
and a second corner 1306. The green particle 1300 can be screen
printed onto a modifying tool. After the green particle 1300 is
screen printed, but before the green particle 1300 is dried, the
green particle 1300 can be placed on a modification tool 1320
having an indentation 1322, or opening, that has a two-dimensional
shape that corresponds to the shape of the outer periphery of the
shaped abrasive particle 800. The surface of the modification tool
1320 can include particular materials having certain properties
(e.g., hydrophobic and/or hydrophilic materials) that can cause the
green particle 1300 to be re-shaped to a final shape, e.g., the
shape of the indentation 1322 in the modification tool 1320. For
example, if the modification tool 1320 is hydrophilic and the green
particle 1300 contains water, the green particle 1300 can be pulled
into the shape of the indentation 1322. As such, the shape of the
green particle 1300 can be modified from the generally triangular
shape depicted in FIG. 13 to the arrow shape of the shaped abrasive
particle 800 illustrated in FIG. 9.
[0088] As such, the final shape can be the shape of the shaped
abrasive particle 800 as depicted in FIG. 9. Notably, such a
process may be used to create the illustrated shaped abrasive
particle having side walls with a depression (e.g., concave shape)
and sharp, narrow corners. Specifically in one embodiment, the
green particles are rounded particles that are then created into
the shape abrasive particles illustrated in FIG. 9. It will be
appreciated that certain corners may further be more pointed, such
that they may experience some reduction in height at the corners or
appear as tapered along the upper surface.
[0089] During the process, after contact with the hydrophobic
surface a first corner radius of the first corner 1304 of the green
particle 1300 can become a modified first corner radius of the
first corner 816 of the shaped abrasive particle 800. Further, a
second corner radius of the second corner 1306 of the green
particle 1300 can be become a modified second corner radius of the
second corner 818 of the shaped abrasive particle 800. In a
particular aspect, the modified first corner radius is less than
the first corner radius and the modified second corner radius is
less than the second corner radius. Further, first corner radius
1302 and the second corner 1304 radius of the green particle 1300
can be reduced by placing the green particle 1300 in contact with a
hydrophobic and/or hydrophilic surface of the modification tool
1320.
[0090] Specifically, the contact of the green particle 1300 with
the surface of the modifying tool having the particular materials
can facilitate reduction of the first corner radius of the green
particle 1300 to the modified first corner radius of the shaped
abrasive particle 800. Further, the contact of the green particle
1300 with the hydrophobic surface can reduce the second corner
radius of the green particle 1300 to the modified second corner
radius of the shaped abrasive particle 800. For example, the
modified first corner radius of the shaped abrasive particle 800
can be less than 50 microns or less than 30 microns or less than 20
microns or less than 10 microns or less than 5 microns or less than
1 micron. Also, the modified second corner radius of the shaped
abrasive particle 800 can be less than 50 microns or less than 30
microns or less than 20 microns or less than 10 microns or less
than 5 microns or less than 1 micron.
[0091] The radius of curvature can be measured from a polished
cross-section of the first or second face using image analysis such
as a Clemex Image Analysis program interfaced with an inverted
light microscope or other suitable image analysis software. The
radius of curvature for each triangular apex can be estimated by
defining three points at each apex when viewed in cross section at
100.times. magnification. A point is placed at the start of the
tip's curve where there is a transition from the straight edge to
the start of a curve, at the apex of the tip, and at the transition
from the curved tip back to a straight edge. The image analysis
software then draws an arc defined by the three points (start,
middle, and end of the curve) and calculates a radius of curvature.
The radius of curvature for at least 30 apexes are measured and
averaged to determine the average tip radius.
[0092] In a particular aspect, after the green particle 1300 is
modified, as described herein, the result is a shaped abrasive
particle 800 that includes at least one exterior corner, e.g., the
first corner 816 or the second corner 818, and the at least one
exterior corner can include a corner radius within a range of at
least 0.5 microns and not greater than 15 microns. As further
indicated in FIG. 8, the body 802 of the shaped abrasive particle
800 can have a thickness 820. The thickness 820 of the body 802 can
be substantially the same along a length of the body 802.
[0093] FIG. 14 through FIG. 17 depict various aspects of a shaped
abrasive particle 1400 that can be made using one or more of the
methods described herein. In a particular aspect, the shaped
abrasive particle 1400 can be made using the method illustrated in
FIG. 6.
[0094] FIG. 14 includes a perspective view of the shaped abrasive
particle 1400. FIG. 15 is a front plan view of the shaped abrasive
particle 1400. The rear plan and both side plan views of the shaped
abrasive particle 1400 are the same as the front plan view depicted
in FIG. 15. FIG. 16 is a top plan view of the shaped abrasive
particle 1400. The bottom plan view is the same as the top plan
view shown in FIG. 16. FIG. 17 is a detailed view of the shaped
abrasive particle 1400 taken at circle 17 in FIG. 15.
[0095] As illustrated, the shaped abrasive particle 1400 can
include a body 1402. The body 1402 can have the shape of a
flattened hemisphere. Specifically, the body 1402 can include a
generally flat lower surface 1404 and a generally arcuate upper
surface 1406. As depicted in FIG. 17, the arcuate upper surface
1406 can form an angle 1408 with respect to the flat lower surface
1404. In a particular aspect, the angle 1408 can be less than 50
degrees. Further, the angle 1408 can be less than 45 degrees, such
as less than 40 degrees, less than 35 degrees, or less than 30
degrees. In another aspect, the angle 1408 can be at least 1
degree, such as at least 2 degrees, at least 3 degrees, at least 4
degrees, at least 5 degrees, at least 8 degrees, or at least 10
degrees.
[0096] As indicated in FIG. 15, the body 1402 of the shaped
abrasive particle 1400 can have a thickness 1410. The thickness
1410 of the body 1402 is greatest along a central axis 1412 and can
decrease from the central axis 1412 outwardly toward an outer
peripheral edge 1414 of the body 1402 of the shaped abrasive
particle 1400. In a particular aspect, the thickness 1410 at the
center of the body 1402 can be greater than or equal to 1 micron.
In another aspect, the thickness 1410 at the center of the body
1402 can be greater than or equal to 15 microns, such as greater
than or equal to 20 microns, or greater than or equal to 25
microns. In another aspect, the thickness 1410 at the center of the
body 1402 can be less than or equal to 5 mm, such as not greater
than 3 mm or not greater than 1 mm or not greater than 800 microns
or not greater than 600 microns or not greater than 400 microns or
not greater than 200 microns or not greater than 100 microns or not
greater than 80 microns or not greater than 50 microns or not
greater than 20 microns. The thickness can be an average thickness
measured from a side view of the abrasive particle. The thickness
can be within a range including any of the minimum and maximum
values noted above.
[0097] As shown in FIG. 16, the body 1402 of the shaped abrasive
particle 1400 can have a diameter 1416. In a particular aspect, the
diameter 1416 of the body 1402 can be at least 1 micron. In another
aspect, the diameter 1416 of the body 1402 can be at least 100
microns, such as at least 500 microns, or at least 1 mm. In another
aspect, the diameter 1416 of the body 1402 can be not greater than
5 mm, such as not greater than 4 mm, not greater than 3 mm, or not
greater than 2 mm. The diameter can be within a range including any
of the minimum and maximum values noted above.
[0098] Further, a ratio, R.sub.TD, of the maximum thickness 1410 of
the body 1402 to the diameter 1416 of the body 1402 can be not
greater than 1.0. In particular, R.sub.TD may be not greater than
0.5, such as not greater than 0.2, not greater than 0.1, or not
greater than 0.05. In another aspect, R.sub.TD may be at least
0.00002. Moreover, R.sub.TD may be at least 0.0001, such as at
least 0.005, at least 0.001, or at least 0.05. R.sub.TD can be
within a range including any of the minimum and maximum values
noted above.
[0099] FIG. 18 illustrates a shaped abrasive particle, e.g., the
shaped abrasive particle 1400 depicted in FIG. 14 through FIG. 17,
in contact with a workpiece 1800. As shown, using the shaped
abrasive particle 1400 to grind, or abrade, the workpiece 1800 in a
direction orthogonal to the length of the shaped abrasive particle
1400, as indicated by arrow 1802 and arrow 1804 can lead to a wide
cutting edge and a low wear flat area.
[0100] The shaped abrasive particles described herein can be formed
such that each respective body can include a crystalline material,
and more particularly, a polycrystalline material. Notably, the
polycrystalline material can include abrasive grains. In one
embodiment, the body can be essentially free of an organic
material, including for example, a binder. More particularly, the
body can consist essentially of a polycrystalline material.
[0101] In an alternative and non-limiting embodiment, the body of
each shaped abrasive particle can be an agglomerate including a
plurality of abrasive particles, grit, and/or grains bonded to each
other to form the body of the abrasive particle. Suitable abrasive
grains can include nitrides, oxides, carbides, borides,
oxynitrides, oxyborides, diamond, and a combination thereof. In
particular instances, the abrasive grains can include an oxide
compound or complex, such as aluminum oxide, zirconium oxide,
titanium oxide, yttrium oxide, chromium oxide, strontium oxide,
silicon oxide, and a combination thereof. In one particular
instance, each shaped abrasive particle can be formed such that the
abrasive grains forming the body thereof can include alumina, and
more particularly, may consist essentially of alumina. Moreover, in
particular instances, the shaped abrasive particle can be formed
from a seeded sol-gel.
[0102] The abrasive grains (i.e., crystallites) contained within
the body may have an average grain size that is generally not
greater than about 100 microns. In other embodiments, the average
grain size can be less, such as not greater than about 80 microns,
not greater than about 50 microns, not greater than about 30
microns, not greater than about 20 microns, not greater than about
10 microns, or even not greater than about 1 micron, not greater
than about 0.9 microns, not greater than about 0.8 microns, not
greater than about 0.7 microns, or even not greater than about 0.6
microns. Still, the average grain size of the abrasive grains
contained within each body can be at least about 0.01 microns, such
as at least about 0.05 microns, at least about 0.06 microns, at
least about 0.07 microns, at least about 0.08 microns, at least
about 0.09 microns, at least about 0.1 microns, at least about 0.12
microns, at least about 0.15 microns, at least about 0.17 microns,
at least about 0.2 microns, or even at least about 0.5 microns. It
will be appreciated that the abrasive grains can have an average
grain size within a range between any of the minimum and maximum
values noted above.
[0103] In accordance with certain embodiments, one or more of the
abrasive particles described herein can be a composite article
including at least two different types of grains within the
respective body. It will be appreciated that different types of
grains are grains having different compositions with regard to each
other. For example, the body can be formed such that is includes at
least two different types of grains, wherein the two different
types of grains can be nitrides, oxides, carbides, borides,
oxynitrides, oxyborides, diamond, and a combination thereof.
[0104] In accordance with an embodiment, the shaped abrasive
particles described herein can have an average particle size, as
measured by the largest dimension measurable on the body thereof,
of at least about 100 microns. In fact, the shaped abrasive
particles can have an average particle size of at least about 150
microns, such as at least about 200 microns, at least about 300
microns, at least about 400 microns, at least about 500 microns, at
least about 600 microns, at least about 700 microns, at least about
800 microns, or even at least about 900 microns. Still, the shaped
abrasive particles can have an average particle size that is not
greater than about 5 mm, such as not greater than about 3 mm, not
greater than about 2 mm, or even not greater than about 1.5 mm. It
will be appreciated that the abrasive particle 300 can have an
average particle size within a range between any of the minimum and
maximum values noted above.
[0105] The shaped abrasive particles of the embodiments herein,
e.g., the bodies thereof, can have particular compositions. For
example, the bodies may include a ceramic material, such as a
polycrystalline ceramic material, and more particularly an oxide.
The oxide may include, for example alumina. In certain instances,
the bodies may include a majority content of alumina, such as at
least about 80 wt % alumina for the total weight of the body, or
such as at least about 90 wt %, at least 95 wt %, at least 95.1 wt
%, at least about 95.2 wt %, at least about 95.3 wt %, at least
about 95.4 wt %, at least about 95.5 wt %, at least about 95.6 wt
%, at least about 95.7 wt %, at least about 95.8 wt %, at least
about 95.9 wt %, at least about 96 wt %, at least about 96.1 wt %,
at least about 96.2 wt %, at least about 96.3 wt %, at least about
96.4 wt %, at least about 96.5 wt %, at least about 96.6 wt %, at
least about 96.7 wt %, at least about 96.8 wt %, at least about
96.9 wt %, at least about 97 wt %, at least about 97.1 wt %, at
least about 97.2 wt %, at least about 975.3 wt %, at least about
97.4 wt %, or even at least about 97.5 wt % alumina for the total
weight of the body. Still, in another non-limiting embodiment, the
bodies may include a content of alumina not greater than about 99.5
wt %, such as not greater than about 99.4 wt %, not greater than
about 99.3 wt %, not greater than about 99.2 wt %, not greater than
about 99.1 wt %, not greater than about 99 wt %, not greater than
about 98.9 wt %, not greater than about 98.8 wt %, not greater than
about 98.7 wt %, not greater than about 98.6 wt %, not greater than
about 98.5 wt %, not greater than about 98.4 wt %, not greater than
about 98.3 wt %, not greater than about 98.2 wt %, not greater than
about 98.1 wt %, not greater than about 98 wt %, not greater than
about 97.9 wt %, not greater than about 97.8 wt %, not greater than
about 97.7 wt %, not greater than about 97.6 wt %, or even not
greater than about 97.5 wt % alumina for the total weight of the
body 1201. It will be appreciated that the bodies may include a
content of alumina within a range between any of the minimum and
maximum values noted above.
[0106] The bodies of the shaped abrasive particles maybe formed to
include certain additives. The additives can be non-organic
species, including but not limited to an oxide. In one particular
instance, the additive may be a dopant material, which may be
present in a particular minor amount sufficient to affect the
microstructure of the material, but present in a greater content
than a trace amount or less. The dopant material may include an
element selected from the group of hafnium, zirconium, niobium,
tantalum, molybdenum, vanadium, lithium, sodium, potassium,
magnesium, calcium, strontium, barium, scandium, yttrium,
lanthanum, cesium, praseodymium, chromium, cobalt, iron, germanium,
manganese, nickel, titanium, zinc, and a combination thereof. In
still a more particular embodiment, the dopant material may include
magnesium, and may be a magnesium-containing species, including but
not limited to, magnesium oxide (MgO).
[0107] According to one embodiment, the magnesium-containing
species can be a compound including magnesium and at least one
other element. In at least one embodiment, the magnesium-containing
compound can include an oxide compound, such that the
magnesium-containing species includes magnesium and oxygen. In yet
another embodiment, the magnesium-containing species can include
aluminum, and more particularly may be a magnesium aluminate
species. For example, in certain instances, the
magnesium-containing species can be a spinel material. The spinel
material may be stoichiometric or non-stoichiometric spinel.
[0108] The magnesium-containing species may be a distinct phase of
material formed in the body as compared to another primary phase,
including for example, an alumina phase. The magnesium-containing
species may be preferentially disposed at the grain boundaries of
the primary phase (e.g., alumina grains). In still other instances,
the magnesium-containing species may be primarily and uniformly
dispersed throughout the volume of the grains of the primary
phase.
[0109] The magnesium-containing species may be a strength-altering
material. For example, in at least one embodiment, the addition of
the magnesium-containing species can be configured to reduce the
strength of the body compared to a body that does not include the
magnesium-containing species.
[0110] Certain compositions of the shaped abrasive particles of the
embodiments can include a particular content of magnesium oxide.
For example, the bodies of any of the shaped abrasive particles may
include a content of a magnesium-containing species of at least
about 0.5 wt %, such as at least about 0.6 wt %, at least about 0.7
wt %, at least about 0.8 wt %, at least about 0.9 wt %, at least
about 1 wt %, at least about 1.1 wt %, at least about 1.2 wt %, at
least about 1.3 wt %, at least about 1.4 wt %, at least about 1.5
wt %, at least about 1.6 wt %, at least about 1.7 wt %, at least
about 1.8 wt %, at least about 1.9 wt %, at least about 2 wt %, at
least about 2.1 wt %, at least about 2.2 wt %, at least about 2.3
wt %, at least about 2.4 wt %, or even at least about 2.5 wt % for
the total weight of the body 1201. In still another non-limiting
embodiment, the body 1201 may include a content of a
magnesium-containing species of not greater than about 5 wt %, such
as not greater than about 4.9 wt %, not greater than about 4.8 wt
%, not greater than about 4.7 wt %, not greater than about 4.6 wt
%, not greater than about 4.5 wt %, not greater than about 4.4 wt
%, not greater than about 4.3 wt %, not greater than about 4.2 wt
%, not greater than about 4.1 wt %, not greater than about 4 wt %,
not greater than about 3.9 wt %, not greater than about 3.8 wt %,
not greater than about 3.7 wt %, not greater than about 3.6 wt %,
not greater than about 3.5 wt %, not greater than about 3.4 wt %,
not greater than about 3.3 wt %, not greater than about 3.2 wt %,
not greater than about 3.1 wt %, not greater than about 3 wt %, not
greater than about 2.9 wt %, not greater than about 2.8 wt %, not
greater than about 2.7 wt %, not greater than about 2.6 wt %, or
even not greater than about 2.5 wt %. It will be appreciated that
the content of a magnesium-containing species within the bodies may
be within a range between any of the minimum and maximum values
noted above. Furthermore, in at least one embodiment, the bodies of
the shaped abrasive particles may consist essentially of alumina
(Al.sub.2O.sub.3) and the magnesium-containing species.
[0111] Moreover, the bodies of the shaped abrasive particle of any
of the embodiments herein may be formed of a polycrystalline
material including grains, which may be made of materials such as
nitrides, oxides, carbides, borides, oxynitrides, diamond, and a
combination thereof. Further, the bodies can be essentially free of
an organic material, essentially free of rare earth elements, and
essentially free of iron. The bodies may be essentially free of
nitrides, essentially free of chlorides, essentially free of
nitrides, or essentially free of oxynitrides. Being essentially
free is understood to mean that the body is formed in a manner to
exclude such materials, but the body may not necessarily be
completely free of such materials as they may be present in trace
amounts or less.
[0112] Certain features, for clarity, described herein in the
context of separate embodiments, may also be provided in
combination in a single embodiment. Conversely, various features
that are, for brevity, described in the context of a single
embodiment, may also be provided separately or in any
subcombination. Further, reference to values stated in ranges
includes each and every value within that range.
[0113] Benefits, other advantages, and solutions to problems have
been described above with regard to specific embodiments. However,
the benefits, advantages, solutions to problems, and any feature(s)
that may cause any benefit, advantage, or solution to occur or
become more pronounced are not to be construed as a critical,
required, or essential feature of any or all the claims.
[0114] The specification and illustrations of the embodiments
described herein are intended to provide a general understanding of
the structure of the various embodiments. The specification and
illustrations are not intended to serve as an exhaustive and
comprehensive description of all of the elements and features of
apparatus and systems that use the structures or methods described
herein. Separate embodiments may also be provided in combination in
a single embodiment, and conversely, various features that are, for
brevity, described in the context of a single embodiment, may also
be provided separately or in any subcombination. Further, reference
to values stated in ranges includes each and every value within
that range. Many other embodiments may be apparent to skilled
artisans only after reading this specification. Other embodiments
may be used and derived from the disclosure, such that a structural
substitution, logical substitution, or another change may be made
without departing from the scope of the disclosure. Accordingly,
the disclosure is to be regarded as illustrative rather than
restrictive.
[0115] The description in combination with the figures is provided
to assist in understanding the teachings disclosed herein. The
following discussion will focus on specific implementations and
embodiments of the teachings. This focus is provided to assist in
describing the teachings and should not be interpreted as a
limitation on the scope or applicability of the teachings. However,
other teachings can certainly be used in this application.
[0116] As used herein, the terms "comprises," "comprising,"
"includes," "including," "has," "having" or any other variation
thereof, are intended to cover a non-exclusive inclusion. For
example, a method, article, or apparatus that comprises a list of
features is not necessarily limited only to those features but may
include other features not expressly listed or inherent to such
method, article, or apparatus. Further, unless expressly stated to
the contrary, "or" refers to an inclusive-or and not to an
exclusive-or. For example, a condition A or B is satisfied by any
one of the following: A is true (or present) and B is false (or not
present), A is false (or not present) and B is true (or present),
and both A and B are true (or present).
[0117] Also, the use of "a" or "an" is employed to describe
elements and components described herein. This is done merely for
convenience and to give a general sense of the scope of the
invention. This description should be read to include one or at
least one and the singular also includes the plural, or vice versa,
unless it is clear that it is meant otherwise. For example, when a
single item is described herein, more than one item may be used in
place of a single item. Similarly, where more than one item is
described herein, a single item may be substituted for that more
than one item.
[0118] Unless otherwise defined, 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 invention belongs. The
materials, methods, and examples are illustrative only and not
intended to be limiting. To the extent not described herein, many
details regarding specific materials and processing acts are
conventional and may be found in reference books and other sources
within the structural arts and corresponding manufacturing
arts.
[0119] Many different aspects and embodiments are possible. Some of
those aspects and embodiments are described herein. After reading
this specification, skilled artisans will appreciate that those
aspects and embodiments are only illustrative and do not limit the
scope of the present invention. Embodiments may be in accordance
with any one or more of the embodiments as listed below.
EMBODIMENTS
[0120] Embodiment 1. A method for forming an abrasive particle
comprising: [0121] forming a green particle having a body including
at least one exterior corner having a first corner radius; and
[0122] contacting at least a portion of the body to a hydrophobic
material and changing the first corner radius to a modified first
corner radius.
[0123] Embodiment 2. The method of embodiment 1, wherein the
modified first corner radius is less than the first corner
radius.
[0124] Embodiment 3. The method of embodiment 1, wherein contacting
includes placing the green particle in contact with a hydrophobic
surface to reduce the first corner radius.
[0125] Embodiment 4. The method of embodiment 1, wherein the
modified first corner radius is less than 50 microns or less than
30 microns or less than 20 microns or less than 10 microns or less
than 5 microns or less than 1 micron.
[0126] Embodiment 5. A shaped abrasive particle having a body
including a first surface, a second surface, and a third surface
extending between the first surface and the second surface, and
wherein the body comprises an exterior corner having a corner
radius within a range of at least 0.5 microns and not greater than
15 microns.
[0127] Embodiment 6. A method for forming shaped abrasive particles
comprising: creating a substrate comprising a sintered ceramic
material; and [0128] cutting the substrate to form a plurality of
shaped abrasive particles from the substrate.
[0129] Embodiment 7. The method of embodiment 6, wherein creating
the substrate comprises: [0130] creating a mixture comprising a
precursor ceramic material; forming the mixture into a green body;
[0131] sintering the green body to form a sintered ceramic material
in the form of a substrate.
[0132] Embodiment 8. The method of embodiment 6, wherein the
substrate is in the form a polyhedral shape.
[0133] Embodiment 9. The method of embodiment 6, wherein the
substrate is in the form of a cuboid.
[0134] Embodiment 10. The method of embodiment 6, wherein cutting
is performed with a 1A8 type dicing blade.
[0135] Embodiment 11. The method of embodiment 6, wherein cutting
is performed using a bonded abrasive thin wheel comprising
superabrasive particles contained in a bond matrix.
[0136] Embodiment 12. The method of embodiment 6, wherein the
sintered ceramic material comprises alumina.
[0137] Embodiment 13. The method of embodiment 6, wherein the
sintered ceramic material comprises alpha alumina.
[0138] Embodiment 14. The method of embodiment 6, wherein cutting
is a computer controlled cutting operation configured to create
shaped abrasive particles having complex three-dimensional
shapes.
[0139] Embodiment 15. The method of embodiment 6, wherein each of
the shaped abrasive particles of the plurality of shaped abrasive
particles have substantially the same shape with respect to each
other.
[0140] Embodiment 16. The method of embodiment 6, wherein at least
a portion of the shaped abrasive particles of the plurality of
shaped abrasive particles have a different two-dimensional shape
with respect each other.
[0141] Embodiment 17. A method of forming abrasive particles
comprising: depositing a free-standing droplet on a substrate; the
droplet comprising a mixture including a precursor ceramic
material; and sintering the free-standing droplet to form a shaped
abrasive particle having an elliptical shape.
[0142] Embodiment 18. The method of embodiment 17, wherein
depositing includes dropping a plurality of drops from a deposition
assembly.
[0143] Embodiment 19. The method of embodiment 18, wherein the
deposition assembly has a selectable deposition volume and is
configured to control the volume of mixture that is deposited for
each free-standing droplet.
[0144] Embodiment 20. The method of embodiment 17, wherein the
free-standing droplet comprises a contact angle with the substrate
of less than 50 degrees or less than 40 degrees or less than 30
degrees.
[0145] Embodiment 21. The method of embodiment 20, wherein the
contact angle is at least 1 degree or at least 2 degrees or at
least 5 degrees or at least 8 degrees or at least 10 degrees.
[0146] Embodiment 22. The method of embodiment 17, further
comprising: [0147] selecting a material of the substrate relative
to the material of the mixture to control a contact angle of the
free-standing droplet on the substrate.
[0148] Embodiment 23. The method of embodiment 17, wherein the
process is a continuous process and the substrate is translated
under a deposition assembly that continuously deposits a plurality
of free-standing droplets onto the substrate as it is translated
under the deposition assembly.
[0149] Embodiment 24. The method of embodiment 17, further
comprising controlling an average particle size of the shaped
abrasive particle based on the volume of material deposited in the
free-standing droplet.
[0150] Embodiment 25. The method of embodiment 17, further
comprising controlling an average particle size of the shaped
abrasive particle based on the material of the substrate and the
material of the mixture.
[0151] The above-disclosed subject matter is to be considered
illustrative, and not restrictive, and the appended claims are
intended to cover all such modifications, enhancements, and other
embodiments, which fall within the true scope of the present
invention. Thus, to the maximum extent allowed by law, the scope of
the present invention is to be determined by the broadest
permissible interpretation of the following claims and their
equivalents, and shall not be restricted or limited by the
foregoing detailed description.
[0152] The Abstract of the Disclosure is provided to comply with
Patent Law and is submitted with the understanding that it will not
be used to interpret or limit the scope or meaning of the claims.
In addition, in the foregoing Detailed Description of the Drawings,
various features may be grouped together or described in a single
embodiment for the purpose of streamlining the disclosure. This
disclosure is not to be interpreted as reflecting an intention that
the claimed embodiments require more features than are expressly
recited in each claim. Rather, as the following claims reflect,
inventive subject matter may be directed to less than all features
of any of the disclosed embodiments. Thus, the following claims are
incorporated into the Detailed Description of the Drawings, with
each claim standing on its own as defining separately claimed
subject matter.
* * * * *
References