U.S. patent application number 16/390988 was filed with the patent office on 2019-10-24 for finishing mediums and finishing suspensions.
The applicant listed for this patent is PostProcess Technologies, Inc.. Invention is credited to Marc Farfaglia, Cassidy Grant, Daniel Joshua Hutchinson.
Application Number | 20190322898 16/390988 |
Document ID | / |
Family ID | 68236815 |
Filed Date | 2019-10-24 |
United States Patent
Application |
20190322898 |
Kind Code |
A1 |
Hutchinson; Daniel Joshua ;
et al. |
October 24, 2019 |
Finishing Mediums And Finishing Suspensions
Abstract
Described are finishing mediums for removing support material
and/or for surface finishing of objects made via additive
manufacturing techniques. The finishing medium is an aqueous
solution containing 1-20% by weight a polyol, 1-20% by weight an
anti-corrosion agent, 0.001-10% by weight a hydrotrope. The
finishing medium may optionally suspend media particles, thereby
forming a finishing suspension. Also described are methods of using
the finishing media and finishing suspensions described herein.
Inventors: |
Hutchinson; Daniel Joshua;
(Buffalo, NY) ; Farfaglia; Marc; (Buffalo, NY)
; Grant; Cassidy; (Buffalo, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PostProcess Technologies, Inc. |
Buffalo |
NY |
US |
|
|
Family ID: |
68236815 |
Appl. No.: |
16/390988 |
Filed: |
April 22, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62660740 |
Apr 20, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24C 11/00 20130101;
B24C 11/005 20130101; C09G 1/02 20130101; B24C 1/083 20130101; B33Y
40/00 20141201 |
International
Class: |
C09G 1/02 20060101
C09G001/02; B33Y 40/00 20060101 B33Y040/00; B24C 1/08 20060101
B24C001/08 |
Claims
1. A finishing medium comprising: 1-20% by weight a polyol;
optionally, 1-20% by weight an anti-corrosion agent; 0.001-10% by
weight a hydrotrope; and water.
2. The finishing medium of claim 1, comprising: 1-20% by weight a
polyol; 1-20% by weight an anti-corrosion agent; 0.001-10% by
weight a hydrotrope; and the remainder is water.
3. The finishing medium of claim 1, wherein the polyol is chosen
from ethylene glycol, propylene glycol, glycerol, methoxytriglycol,
ethoxytriglycol, butoxytriglycol, diethylene glycol n-butyl 30
ether acetate, diethylene glycol monobutyl ether, ethylene glycol
n-butyl ether acetate, ethylene glycol monobutyl ether, diethylene
glycol monoethyl ether, ethylene glycol phenyl ether, diethylene
glycol monohexyl ether, ethylene glycol monohexyl ether, diethylene
glycol monomethyl ether, ethylene glycol monopropyl ether,
di(propylene glycol) methyl ether, dipropylene glycol methyl ether
acetate, dipropylene glycol n-butyl ether, propylene glycol
diacetate, propylene glycol methyl ether, propylene glycol
monomethyl ether acetate, propylene glycol n-butyl ether, propylene
glycol phenyl ether, tripropylene glycol methyl ether, tripropylene
glycol n-butyl ether, dipropylene glycol dimethyl ether,
2-butoxyethanol, and combinations thereof.
4. The finishing medium of claim 1, wherein the anti-corrosion
agent is chosen from one or more organooxygen compound, one or more
organoamine compound, one or more organosulfur compound, one or
more organophosphorus compound, and combinations thereof.
5. The finishing medium of claim 1, wherein the anti-corrosion
agent is chosen from ethanolamine, diethanolamine, zinc
dialkyldithiophosphate, benzotriazole, dibutylamine, and
combinations thereof.
6. The finishing medium of claim 1, wherein the hydrotrope is
chosen from sodium xylene sulfonate, xylene sulfonic acid, calcium
xylene sulfonate, potassium xylene sulfonate, cumene sulfonic acid,
sodium cumene sulfonate, toluene sulfonic acid, sodium toluene
sulfonate, and combinations thereof.
7. The finishing medium of claim 6, wherein the hydrotrope is a
mixture of hydrotrope isomers.
8. The finishing medium of claim 6, wherein the hydrotrope is
provided via an aqueous solution comprising 1-50% by weight a
hydrotrope.
9. The finishing medium of claim 1, wherein the finishing medium
has a pH of 4 to 14.
10. The finishing medium of claim 1, wherein: the polyol is
propylene glycol; the anti-corrosion agent is triethanolamine; and
the hydrotrope is an aqueous solution comprising 40% by weight
sodium xylene sulfonate.
11. The finishing medium of claim 1, comprising: 10% by weight
propylene glycol; 10% by weight triethanolamine; 4% by weight the
aqueous solution having 40% by weight sodium xylene sulfonate; and
76% by weight water, wherein the finishing medium has pH of 4 to
14.
12. A finishing suspension comprising a finishing medium of claim 1
and media particles.
13. The finishing suspension of claim 12, wherein the media
particles are chosen from aluminum-based particles, stainless steel
particles, steel particles, ceramic particles, and combinations
thereof.
14. The finishing suspension of claim 12, wherein the media
particles are chosen from glass beads, aluminum oxide, silica,
zirconium oxide, zirconia, zirconium, silicon carbide, plastic,
garnet, copper, corn cob, walnut shells, mica, feldspar, pumice,
and combinations thereof.
15. The finishing suspension of claim 12, wherein the media
particles have a longest linear dimension of 1-1000 .mu.m.
16. A method of finishing an object made from an additive
manufacturing technique ("AMT Object") comprising, applying a
finishing suspension of claim 12 to an AMT Object such that a
portion of the AMT Object and/or support material or a portion
thereof is removed.
17. The method of claim 16, wherein applying the finishing
suspension comprises spraying the finishing suspension at the AMT
Object.
18. The method of claim 17, wherein the finishing suspension is
sprayed at a pressure of 0-60 psi.
19. The method of claim 16, wherein the finishing suspension is at
a temperature of 50-140.degree. F.
20. The method of claim 16, wherein the AMT Object is made by fused
deposition modeling, selective laser sintering, stereolithography,
multi-jet fusion, direct metal laser sinter/binder jetting methods,
or a combination thereof.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/660,740 filed on Apr. 20, 2018, the disclosure
of which is hereby incorporated by reference.
FIELD OF THE DISCLOSURE
[0002] This application relates generally to finishing mediums for
removing support material and/or for surface finishing of objects
made via additive manufacturing techniques ("AMT"). Some additive
manufacturing techniques are commonly referred to as "3D-printing."
Such 3D-printing techniques include Polyjet, fused deposition
modeling (FDM), selective laser sintering (SLS), stereolithography
(SLA), multi jet fusion (MJF), direct metal laser sintering (DMLS),
binder jetting, and others.
BACKGROUND OF THE DISCLOSURE
[0003] AMT processes are normally carried out by a
computer-controlled device (e.g., a printer) that creates an object
(an "AMT Object") by sequentially applying material. That is, an
AMT Object is "printed," for example, using an inkjet printer head
that additively deposits material in such a way that the AMT Object
is created (printed) from a starting platform (a "printing tray" or
a "build tray"). Often, AMT processes, including 3D-printing,
commonly require additional material ("support material") to be
printed for the purpose of supporting portions of the AMT Object
during printing. This support material buttresses the AMT Object to
prevent issues like sagging. Eventually, it may be desirable to
remove some or all of the support material, for example, after
printing is complete. In addition, objects created by an AMT
process can have rough, unfinished surfaces. These surfaces may
show the build lines, which are indicative of the manner in which
material was printed during the AMT process. As used herein, unless
otherwise indicated, the term "finishing" refers to removing
undesirable material from an AMT Object so as to produce a finished
AMT Object. Finishing can include one or more processes, including,
but not limited to, removing undesirable metal powder, removing
undesirable print material, removing undesirable support material
and/or making rough surfaces smoother. Sometimes, as in the
3D-printing industry, finishing may be referred to as
"cleaning."
[0004] Prior methods of finishing rely on techniques that require a
person to apply and manage the finishing procedure, often on an
object-by-object basis, which is expensive, inconsistent, and does
not scale easily when production runs are larger than only a few
objects. As such, there is a need for a finishing medium/suspension
that reduces the amount of time and attention that is required from
a person to finish an AMT Object, consistent from object-to-object,
and scales with large production runs.
SUMMARY OF THE DISCLOSURE
[0005] The present disclosure describes finishing mediums and
finishing suspensions for removing support material and/or for
surface finishing of objects created by additive manufacturing
techniques. The finishing medium may suspend media particles, and
the finishing medium may flow through a machine that applies (e.g.,
sprays) the finishing medium to the AMT Object being finished. The
combination of finishing medium and media particles may be referred
to as a "finishing suspension." Using a finishing suspension that
is in keeping with the invention, the primary means for finishing
is mechanical and chemical in nature.
[0006] A finishing medium that is in keeping with the invention may
be combined with one or more media particles, thereby forming a
finishing suspension. Media particles may aid in providing a
mechanical force to remove support material and/or a portion of the
object being finished. Examples of media particles include, but are
not limited to, glass beads, steel (e.g., stainless steel)
particles, ceramic materials/particles, aluminum oxide particles
(e.g., alumina particles), silicon oxide particles (e.g., silica
particles), zirconium oxide particles (e.g., zirconia particles),
zirconium particles, silicon carbide particles, plastic particles,
garnet particles, copper particles, corn cob particles, walnut
shells, mica particles, feldspar particles, pumice particles, and
the like. A finishing medium may be combined with a single type of
media particle (e.g., solely alumina, stainless steel particles,
ceramic particles (e.g., silica-based particles, silicon-based
particles, and the like), or the like). Alternatively, a finishing
suspension may have two or more types of media particles (e.g.,
alumina, stainless steel particles, ceramic particles (e.g.,
silica-based particles, silicon-based particles, and the like), and
the like, and combinations thereof) and/or media particles of
different sizes (e.g., alumina and stainless steel particles, where
the alumina particles all have the same average size and the
stainless steel particles have a different average size, or alumina
where the alumina particles are various sizes). Such media
particles can have a longest linear dimension (e.g., a diameter or
radius) of 0.1-1000 including all 0.1 .mu.m values and ranges
therebetween (e.g., 1-700 .mu.m or 1-500 .mu.m). The media
particles may be of various shapes, such as, for example, round,
oblong, irregular, jagged, angular, cubic, rectangular, and
cylindrical. Media particles of one shape may be used with media
particles of a different shape (e.g., round particles may be used
with jagged particles). Media particles may be used to abrade
and/or polish the AMT Object. The abrasion and/or polishing effect
may be dependent on the shape and size of the media particles and
the application pressure. For example, 1 to 100 pounds of media
particles, including all 0.1 pound values and ranges therebetween,
can be added for every 25 to 30 gallons of finishing medium,
including every 0.1 gallon value and range therebetween. Thus, the
ratio of pounds of media particles to gallons of finishing medium
may be 1:30 to 4:1, including all integer ratio values and ranges
therebetween. In various other examples, a finishing suspension
comprises 1 to 2 pounds of media particles per gallon of finishing
medium, including every 0.01 pound value and range
therebetween.
[0007] The present disclosure describes a finishing medium having:
[0008] 1-20% by weight a polyol; [0009] optionally, 1-20% by weight
an anti-corrosion agent; [0010] 0.001-10% by weight a hydrotrope;
and the remainder is water.
[0011] A polyol of the finishing medium may be chosen from ethylene
glycol, propylene glycol, glycerol, methoxytriglycol,
ethoxytriglycol, butoxytriglycol, diethylene glycol n-butyl 30
ether acetate, diethylene glycol monobutyl ether, ethylene glycol
n-butyl ether acetate, ethylene glycol monobutyl ether, diethylene
glycol monoethyl ether, ethylene glycol phenyl ether, diethylene
glycol monohexyl ether, ethylene glycol monohexyl ether, diethylene
glycol monomethyl ether, ethylene glycol monopropyl ether,
di(propylene glycol) methyl ether, dipropylene glycol methyl ether
acetate, dipropylene glycol n-butyl ether, propylene glycol
diacetate, propylene glycol methyl ether, propylene glycol
monomethyl ether acetate, propylene glycol n-butyl ether, propylene
glycol phenyl ether, tripropylene glycol methyl ether, tripropylene
glycol n-butyl ether, dipropylene glycol dimethyl ether,
2-butoxyethanol, and the like, and combinations thereof. An
anti-corrosion agent of the finishing medium may be chosen from
organooxygen compounds, organoamine compounds, organosulfur
compounds, organophosphorus compounds, and combinations thereof.
Examples of anti-corrosion agents include, but are not limited to,
ethanolamine, diethanolamine, zinc dialkyldithiophosphate,
benzotriazole, dibutylamine, and combinations thereof. A hydrotrope
of the finishing medium may be chosen from sodium xylene sulfonate,
xylene sulfonic acid, calcium xylene sulfonate, potassium xylene
sulfonate, cumene sulfonic acid, sodium cumene sulfonate, toluene
sulfonic acid, sodium toluene sulfonate, and combinations thereof.
The hydrotrope may be a mixture of hydrotrope isomers. The
hydrotrope may be provided via an aqueous solution comprising 1-50%
by weight a hydrotrope.
[0012] A finishing medium may further comprise media particles
thereby forming a finishing suspension. The media particles may be
chosen from aluminum-based particles, stainless steel particles,
ceramic particles, and combinations thereof. The media particles
may have a size of 1-1000 .mu.m.
[0013] The finishing medium may include propylene glycol,
triethanolamine, and sodium xylene sulfonate ("SXS"). The SXS may
be supplied as an aqueous solution having 40% by weight SXS.
[0014] The finishing medium may have: [0015] 10% by weight
propylene glycol; [0016] 10% by weight triethanolamine; [0017] 4%
by weight an aqueous solution having 40% by weight SXS; and [0018]
76% by weight water, [0019] wherein the pH of the finishing medium
is from 4 to 14, (e.g., a pH of 7-14 or 4-9 or 8). The media
particles may be suspended in the finishing medium, thereby forming
a finishing suspension.
[0020] A method of finishing an AMT Object may comprise: [0021] (i)
applying a finishing medium that is in keeping with the invention
to an AMT Object such that a portion of the AMT Object is removed.
[0022] The finishing medium may be sprayed onto the AMT Object. The
finishing medium may sprayed at a pressure up to 60 psi at a
temperature of 50-140.degree. F.
[0023] A finishing medium that is in keeping with the invention may
have a pH from 4 to 14.
[0024] An AMT Object may be made by fused deposition modeling,
selective laser sintering, stereolithography, multi-jet fusion,
and/or direct metal laser sinter/binder jetting methods.
BRIEF DESCRIPTION OF THE FIGURES
[0025] For a fuller understanding of the nature and objects of the
invention, reference should be made to the following detailed
description taken in conjunction with the accompanying figures.
[0026] FIG. 1A and FIG. 1B are each a photo of an AMT Object made
by direct metal laser sintering (DMLS) prior to finishing. FIG. 1A
shows a side of the object, and FIG. 1B shows a bottom of the
object. FIG. 1C and FIG. 1D are each a photo of the same AMT Object
shown in FIGS. 1A and 1B after applying a finishing medium that is
in keeping with the invention. FIG. 1C shows the side and bottom of
the finished object, and FIG. 1D shows the bottom of the finished
object.
[0027] FIG. 2 is a diagram of a machine that may be used to apply a
finishing medium that is in keeping with the invention. FIG. 2
shows a single-axis fusillade jet (1), compressed air (2),
detergent (i.e., the finishing medium) (3), suspended solids (i.e.,
media particles) (4), rotating t-slotted turntable (5), debris
filter (6), detergent/slurry (i.e., the finishing suspension) (7),
pump suction (8), and a single axis fusillade jet (9). Such a
machine may be the same or similar to the apparatuses disclosed in
U.S. patent application Ser. No. 16/209,778.
[0028] FIG. 3 is a flow diagram of a method of using a finishing
suspension that is in keeping with the invention.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0029] Although the invention will be described in terms of certain
examples, other examples, including examples that do not provide
all of the benefits and features set forth herein, are also within
the scope of the invention. Various changes to the composition of a
finishing medium or a finishing suspension and/or method of
finishing an AMT Object may be made without departing from the
scope of the invention.
[0030] Ranges of values are disclosed herein. The ranges set out a
lower limit value ("LLV") and an upper limit value ("ULV"). Unless
specified otherwise, the LLV, ULV, and all values between the LLV
and ULV are part of the range.
[0031] The present disclosure describes finishing mediums for
removing support material and for surface finishing of AMT Objects.
The finishing medium suspends media particles (forming a finishing
suspension) and allows the media particles to flow through a
machine that applies (e.g., sprays) the finishing suspension to the
AMT Object being finished. The primary means for finishing using a
finishing suspension that is in keeping with the invention is
mechanical and chemical in nature. That mechanical aspect may be
achieved by media particles impacting the outer surface of the AMT
Object and the chemical aspect may be achieved through dissolution
of dissolvable portions of the AMT Object.
[0032] As used herein, unless otherwise indicated, the term
"support material" refers to material that is operatively arranged
to support portions of an AMT Object during an additive
manufacturing process, but which is undesirable once the
manufacturing process is complete. Support material can comprise
the same material as the object that is being manufactured, or can
be made of a different material. Materials that can be removed
during finishing include, but are not limited to, materials used
during Polyjet 3D-printing (e.g., SUP705, SUP706, SUP707, SUP708,
and the like, and combinations thereof), fused deposition modeling
(FDM) 3D-printing (e.g., SR20, SR30, SR100, SR110, and the like,
and combinations thereof), selective laser sintering (SLS)
3D-printing (e.g., nylon, polystyrene, steel, titanium, and the
like), stereolithography (SLA) 3D-printing (e.g., photopolymers,
light-activated resin, and the like), multi jet fusion (MJF)
3D-printing (e.g., PA 12 (polyamide) and the like), DMLS, and
binder jetting 3D-printing (e.g., steel, aluminum, titanium,
copper, and the like, and combinations thereof), acrylonitrile
butadiene styrene (ABS), and/or PLA (polylactic acid).
[0033] A finishing medium that is in keeping with the invention may
be used to carry particles for removing support material and/or
removing a portion of the object being finished. The combination of
a finishing medium and media particles is referred to herein as a
finishing suspension.
[0034] The finishing medium may comprise a polyol, an
anti-corrosion agent, a hydrotrope, and water. Such a finishing
medium may have a pH of 4 to 14 (e.g., 7 to 14 or 8).
[0035] The finishing medium may comprise: [0036] (a) 1-20% by
weight a polyol, including all 0.01% values and ranges
therebetween; [0037] (b) optionally, 1-20% by weight an
anti-corrosion agent, including all 0.01% values and ranges
therebetween; [0038] (c) 0.001-10% by weight a hydrotrope,
including all 0.0001% values and ranges therebetween; and [0039]
(d) the remainder may be water. [0040] Such a finishing medium may
have a pH of 4 to 14 (e.g., 7 to 14 or 8).
[0041] A polyol, which may serve as a lubricating agent in a
finishing medium that is in keeping with the invention, may aid in
coating the object being finished. Such a coating may aid in
dissolving undesired support material. Examples of polyols (e.g.,
glycols and glycol ethers) suitable for a finishing medium that is
in keeping with the invention include, but are not limited to,
propylene glycol, ethylene glycol, glycerol, methoxytriglycol,
ethoxytriglycol, butoxytriglycol, diethylene glycol n-butyl 30
ether acetate, diethylene glycol monobutyl ether, ethylene glycol
n-butyl ether acetate, ethylene glycol monobutyl ether, diethylene
glycol monoethyl ether, ethylene glycol phenyl ether, diethylene
glycol monohexyl ether, ethylene glycol monohexyl ether, diethylene
glycol monomethyl ether, ethylene glycol monopropyl ether,
di(propylene glycol) methyl ether, dipropylene glycol methyl ether
acetate, dipropylene glycol n-butyl ether, propylene glycol
diacetate, propylene glycol methyl ether, propylene glycol
monomethyl ether acetate, propylene glycol n-butyl ether, propylene
glycol phenyl ether, tripropylene glycol methyl ether, tripropylene
glycol n-butyl ether, dipropylene glycol dimethyl ether,
2-butoxyethanol, and the like, and combinations thereof. For
example, a finishing medium that is in keeping with the invention
may be 1-50% by weight a polyol, including all 0.01% values and
ranges therebetween, relative to the total weight of the finishing
medium. In an example, a finishing medium that is in keeping with
the invention may be 1-20% by weight a polyol, 1-10% by weight a
polyol, 10-20% by weight a polyol, or 1-15% by weight a polyol.
[0042] An anti-corrosion agent in a finishing medium that is in
keeping with the invention may be included in order to keep metal
components of the finishing machine and build plates from
corroding. Anti-corrosion agents may be, for example, organooxygen
compounds, organoamine compounds, organosulfur compounds,
organophosphorus compounds, or a combination thereof. Examples of
anti-corrosion agents suitable for a finishing medium that is in
keeping with the invention include, but are not limited to,
ethanolamine, diethanolamine, zinc dialkyldithiophosphate,
benzotriazole, dibutylamine, combinations thereof, and the like.
For example, a finishing medium that is in keeping with the
invention may be 1-20% by weight an anti-corrosion agent, including
all 0.01% values and ranges therebetween, relative to the total
weight of the finishing medium.
[0043] A hydrotrope may be included in a finishing medium that is
in keeping with the invention in order to aid in solubilizing
organic materials (e.g., the organic components of a finishing
medium and resins from the object) in water. Examples of
hydrotropes suitable for a finishing medium that is in keeping with
the invention include, but are not limited to, SXS, xylene sulfonic
acid, calcium xylene sulfonate, potassium xylene sulfonate, cumene
sulfonic acid, sodium cumene sulfonate, toluene sulfonic acid,
sodium toluene sulfonate, and combinations thereof. Such
hydrotropes can be added to the finishing medium as a solid or can
be added to the finishing medium as an aqueous solution comprising
1-50% hydrotrope by weight, including all 1% values and ranges
therebetween. Such hydrotropes can be a mixture of isomers (e.g.,
stereoisomers, constitutional isomers, and the like). For example,
a finishing medium that is in keeping with the invention may be
0.001-10% by weight a hydrotrope, including all 0.0001% values and
ranges therebetween, relative to the total weight of the finishing
medium.
[0044] A finishing medium that is in keeping with the invention may
be combined with one or more media particles. Herein, the
combination of a finishing medium containing media particles is
referred to as a finishing suspension. Media particles may aid in
providing a mechanical force to remove support material and/or a
portion of the object being finished. Examples of media particles
include, but are not limited to, glass beads, steel (e.g.,
stainless steel) particles, ceramic materials/particles, aluminum
oxide particles (e.g., alumina particles), silicon oxide particles
(e.g., silica particles), zirconium oxide particles (e.g., zirconia
particles), zirconium particles, silicon carbide particles, plastic
particles, garnet particles, copper particles, corn cob particles,
walnut shells, mica particles, feldspar particles, pumice
particles, and the like. A finishing medium may be combined with a
single type of media particles (e.g., solely alumina, stainless
steel particles, ceramic particles (e.g., silica-based particles,
silicon-based particles, and the like), or the like).
Alternatively, a finishing suspension may have two or more types of
media particles (e.g., alumina, stainless steel particles, ceramic
particles (e.g., silica-based particles, silicon-based particles,
and the like), and the like, and combinations thereof) and/or media
particles of different sizes (e.g., alumina and stainless steel
particles, where the alumina particles all have the same average
size and the stainless steel particles have a different average
size, or alumina where the alumina particles are various sizes).
Such media particles can have a longest linear dimension (e.g., a
diameter or radius) of 0.1-1000 .mu.m, including all 0.1 .mu.m
values and ranges therebetween (e.g., 1-700 .mu.m or 1-500 .mu.m).
The media particles may be of various shapes, such as, for example,
round, oblong, irregular, jagged, angular, cubic, rectangular, and
cylindrical. Media particles of one shape may be used with media
particles of a different shape (e.g., round particles may be used
with jagged particles). Media particles may be used to abrade
and/or polish the AMT Object. The abrasion and/or polishing effect
may be dependent on the shape and size of the media particles and
the application pressure. For example, 1 to 100 pounds of media
particles, including all 0.1 pound values and ranges therebetween,
can be added for every 25 to 30 gallons of finishing medium,
including every 0.1 gallon value and range therebetween. Thus, the
ratio of pounds of media particles to gallons of finishing medium
may be 1:30 to 4:1, including all integer ratio values and ranges
therebetween. In various other examples, a finishing suspension
comprises 1 to 2 pounds of media particles per gallon of finishing
medium, including every 0.01 pound value and range
therebetween.
[0045] In a particular example of the invention, the finishing
medium can comprise: [0046] (a) 1-20% by weight a propylene glycol,
including all 0.01% values and ranges therebetween; [0047] (b)
1-20% by weight triethanolamine, including all 0.01% values and
ranges therebetween; [0048] (c) 0.001-10% by weight SXS, including
all 0.0001% values and ranges therebetween; and [0049] (d) the
remainder is water.
[0050] Such a finishing medium may have a pH of 4 to 14, including
all 0.01 pH values and ranges therebetween (e.g., a pH of 7-14 or
4-9 or 8). In a particular example, a finishing suspension
comprises a finishing medium comprising: [0051] (a) 10% by weight a
propylene glycol; [0052] (b) 10% by weight triethanolamine; [0053]
(c) 4% by weight a 40% by weight aqueous solution of SXS; and
[0054] (d) the remainder is water. [0055] Such a finishing medium
may have a pH of about 8.
[0056] For example, the finishing suspension can comprise a
finishing medium comprising: [0057] (a) 1-20% by weight a propylene
glycol, including all 0.01% values and ranges therebetween; [0058]
(b) 1-20% by weight triethanolamine, including all 0.01% values and
ranges therebetween; [0059] (c) 0.001-10% by weight sodium xylene
sulfonate, including all 0.0001% values and ranges therebetween;
and [0060] (d) the remainder may be water, and [0061] media
particles chosen from the group consisting of alumina particles,
stainless steel particles, ceramic particles (e.g., silica-based
particles, silicon-based particles, and the like), and combinations
thereof. There may be 1 to 2 pounds of media particles for every
gallon of finishing medium. Such a finishing medium/suspension may
have a pH of 7 to 14, including all 0.01 pH values and ranges
therebetween. In a particular example, the finishing suspension can
comprise a finishing medium comprising: [0062] (a) 10% by weight a
propylene glycol; [0063] (b) 10% by weight triethanolamine,
including all 0.01% values and ranges therebetween; [0064] (c) 4%
by weight a 40% by weight aqueous solution of SXS; and [0065] (d)
the remainder is water, and [0066] media particles selected from
the group consisting of alumina particles, stainless steel
particles, ceramic particles, and combinations thereof. Such a
finishing medium/suspension may have a pH of about 8 (e.g., a pH of
8.+-.0.5).
[0067] A finishing medium that is in keeping with the invention may
help reduce media attrition. Media attrition occurs when the media
particles inside the machine applying the finishing suspension
break down (e.g., mechanically fracture) into a form that is less
effective or ineffective. The media particles are less effective or
ineffective when the particles are too small to carry enough
momentum to impart an effective force on the AMT Object for
purposes of removing material from the object. Particle size
changes because large particles may fracture when impacting the
object and/or as a result of being pumped. With time, the average
size of the particles will become smaller and thus decrease in
mass, and, as such, each particle becomes less effective at
removing material from the object as they become smaller.
[0068] The invention may be embodied as a method of using a
finishing medium/suspension. The steps of such a method may be
sufficient to remove undesirable material (e.g., support material,
undesirable print material, undesirable metal, and the like) from
an AMT Object. The method may comprise: [0069] (a) providing (301
in FIG. 3) a finishing medium/suspension that is in keeping with
the invention; and [0070] (b) applying (303 in FIG. 3) (e.g.,
spraying) the finishing medium/suspension to an AMT Object, such
that a portion of the object is removed.
[0071] Applying the finishing medium to an AMT Object may involve
spraying and/or otherwise coating the object, such that the
finishing medium/suspension is applied to the object so that
mechanical force is exerted on the object. To increase the speed
and pressure of the finishing medium/suspension leaving the nozzle,
air may be simultaneously forced through the same nozzle as the
finishing medium/suspension to increase the velocity of the
finishing medium/suspension leaving the nozzle. An AMT Object may
be sprayed with the finishing medium/suspension at a pressure up to
60 psi (e.g., 35 psi), inclusive. Along with the finishing
medium/suspension, air may be forced into the conduit carrying the
finishing medium/suspension.
[0072] A finishing medium or finishing suspension that is in
keeping with the invention may be heated (302 in FIG. 3) prior to
or during application (e.g., spraying). The finishing medium or
finishing suspension may have a temperature of 50-140.degree. F.,
(e.g., 70-100.degree. F.), including all 0.01.degree. F. values and
ranges therebetween. Following application of the finishing
medium/suspension, the object may be rinsed with, for example,
water (304 in FIG. 3) in order to remove the finishing medium or
suspension and the AMT Object may be dried.
[0073] A finishing medium or finishing suspension that is in
keeping with the invention may be applied by a machine (e.g., the
PostProcess.TM. DECI DUO finishing unit). Such a machine may be the
same or similar to the apparatuses disclosed in U.S. patent
application Ser. No. 16/209,778. Such a machine may pump the
finishing medium or finishing suspension through a nozzle that is
directed at the object. The finishing medium or finishing
suspension may be forced out of the nozzle at a high velocity.
During such application (e.g., spraying), the object may be sprayed
with a finishing medium or a finishing suspension (e.g., containing
alumina particles, stainless steel particles, ceramic particles, or
the like). The finishing medium (and media particles) impacts the
outer surface of the object. The force of impact on the outer
surface of the object assists in removing undesirable material
(e.g., undesirable resin, undesirable print material, undesirable
metal powder, undesirable support material, and the like). During
application of the finishing medium or finishing suspension, the
AMT Object may be rotated (e.g., rotated via a turntable) so that
the AMT Object is thoroughly coated/impacted with the finishing
medium and/or media particles. Generally, an initial finishing step
can utilize a finishing suspension having larger media particles
(e.g., larger media particles, such as, for example, aluminum
oxide, silicon carbide, stainless steel, titanium) and then
polished with a finishing suspension having smaller suspended
particles (e.g., ceramic media particles, such as, for example,
ZIRBLAST.RTM. and MICROBLAST.RTM. blasting media). In an example,
larger and/or jagged particles may be used for abrading and
spherical particles may be used for polishing.
[0074] Roughness average ("Ra") can be used to determine when an
object is finished. A lower Ra indicates a smooth object, whereas a
higher Ra indicates a rougher object. An object may be finished
until the desired Ra is achieved. Ra is often measured in
micro-inches. A lower roughness average indicates a smoother
object.
[0075] The following Statements describe non-limiting examples in
keeping with the present invention. [0076] Statement 1. A finishing
medium comprising: 1-20% by weight a polyol; optionally, 1-20% by
weight an anti-corrosion agent; 0.001-10% by weight a hydrotrope;
and water (e.g., the remainder of the finishing medium may be
water). [0077] Statement 2. The finishing medium according to
Statement 1, where the polyol is chosen from ethylene glycol,
propylene glycol, glycerol, methoxytriglycol, ethoxytriglycol,
butoxytriglycol, diethylene glycol n-butyl 30 ether acetate,
diethylene glycol monobutyl ether, ethylene glycol n-butyl ether
acetate, ethylene glycol monobutyl ether, diethylene glycol
monoethyl ether, ethylene glycol phenyl ether, diethylene glycol
monohexyl ether, ethylene glycol monohexyl ether, diethylene glycol
monomethyl ether, ethylene glycol monopropyl ether, di(propylene
glycol) methyl ether, dipropylene glycol methyl ether acetate,
dipropylene glycol n-butyl ether, propylene glycol diacetate,
propylene glycol methyl ether, propylene glycol monomethyl ether
acetate, propylene glycol n-butyl ether, propylene glycol phenyl
ether, tripropylene glycol methyl ether, tripropylene glycol
n-butyl ether, dipropylene glycol dimethyl ether, 2-butoxyethanol,
and combinations thereof. [0078] Statement 3. The finishing medium
according to Statement 1 or Statement 2, where the anti-corrosion
agent is chosen from one or more organooxygen compound, one or more
organoamine compound, one or more organosulfur compound, one or
more organosulfur compound, one or more organophosphorus compound,
and combinations thereof, where non-limiting examples include
ethanolamine, diethanolamine, zinc dialkyldithiophosphate,
benzotriazole, dibutylamine, and combinations thereof. [0079]
Statement 4. The finishing medium according to any one of the
preceding Statements, where the hydrotrope is chosen from sodium
xylene sulfonate, xylene sulfonic acid, calcium xylene sulfonate,
potassium xylene sulfonate, cumene sulfonic acid, sodium cumene
sulfonate, toluene sulfonic acid, sodium toluene sulfonate, and
combinations thereof. [0080] Statement 5. The finishing medium
according to Statement 4, where the hydrotrope is a mixture of
hydrotrope isomers. [0081] Statement 6. The finishing medium
according to Statement 4 or Statement 5, where the hydrotrope is
provided via an aqueous solution comprising 1-50% by weight a
hydrotrope. [0082] Statement 7. The finishing medium according to
any one of the preceding Statements, where the finishing medium has
a pH of 4 to 14 (e.g., 7 to 14 or 4 to 9 or 8). [0083] Statement 8.
The finishing medium according to any one of the preceding
Statements, where the polyol is propylene glycol; the
anti-corrosion agent is triethanolamine; and the hydrotrope is an
aqueous solution comprising 40% by weight sodium xylene sulfonate.
[0084] Statement 9. The finishing medium according to any one of
the preceding Statements, comprising: 10% by weight propylene
glycol; 10% by weight triethanolamine; 4% by weight the aqueous
solution having 40% by weight sodium xylene sulfonate; and 76% by
weight water, where the finishing medium has pH of 4 to 14 (e.g., 7
to 14 or 4 to 9 or 8). [0085] Statement 10. A finishing suspension
comprising media particles and a finishing medium according to any
one of the preceding Statements. [0086] Statement 11. The finishing
suspension according to Statement 10, where the media particles are
chosen from glass beads, steel (e.g., stainless steel), ceramic
materials, aluminum oxide/alumina, silica, zirconium, silicon
carbide, plastic, garnet, copper, corn cob, walnut shells, mica,
feldspar, pumice, and combinations thereof, where the media
particles may be of various shapes, such as, for example, round,
oblong, irregular, jagged, angular, cubic, rectangular, and
cylindrical. [0087] Statement 12. The finishing suspension
according to Statement 10 or Statement 11, where the media
particles have a longest linear dimension of 0.1-1000 .mu.m (e.g.,
1-700 .mu.m or 1-500 .mu.m). [0088] Statement 13. A method of
finishing an AMT Object comprising applying a finishing suspension
according to any one of Statements 10-12 to an AMT Object such that
a portion of the AMT Object is removed. [0089] Statement 14. The
method according to Statement 13, where support material or a
portion thereof is removed. [0090] Statement 15. The method
according to Statement 13, where applying the finishing suspension
comprises spraying the finishing suspension on the AMT Object.
[0091] Statement 16. The method according to Statement 15, where
the finishing suspension is sprayed at a pressure of 0-60 psi.
[0092] Statement 17. The method according to any one of Statements
13-16, where the finishing suspension is at a temperature of
50-140.degree. F. [0093] Statement 18. The method according to any
one of Statements 13-17, where the object is made by fused
deposition modeling, selective laser sintering, stereolithography,
multi jet fusion, direct metal laser sinter/binder jetting methods,
or a combination thereof.
[0094] The following example is presented to illustrate an
embodiment of the invention. It is not intended to limit the scope
of the invention.
EXAMPLE 1
[0095] This example describes a method of using a finishing
medium/suspension that is in keeping with the invention.
[0096] The AMT Object in FIG. 1A and FIG. 1B was printed by a DMLS
process known in the art. The object, which was made from Ti6A14V,
was finished using a finishing medium having: [0097] (a) 10% by
weight propylene glycol; [0098] (b) 10% by weight triethanolamine;
[0099] (c) 4% by weight a 40% by weight aqueous solution of sodium
xylene sulfonate; and [0100] (d) the remainder was water. [0101]
Such a finishing medium had a pH of about 8. The finishing medium
was combined with 36 grit (450 .mu.m) aluminum oxide media
particles. The resulting finishing suspension was initially heated
to a temperature of about 80.degree. F. and the AMT Object was
abraded by spraying the finishing suspension at the object at a
pressure of 35 psi. Air was supplied to the finishing suspension
through an orifice located prior to the nozzle. Upstream of the
orifice, the air pressure was 70 psi. The finishing suspension was
applied (e.g., sprayed) to the object for 110 minutes while the
object was on a turntable rotating at 10 rotations per minute
(rpm).
[0102] The object was then polished using the finishing medium
combined with ZIRBLAST.RTM. (a combination of zirconia, silica, and
alumina, the majority being zirconia), having a size of 300 grit
(34 .mu.m). The finishing suspension was applied to (e.g., sprayed)
the object for 40 minutes while the object was on a turntable
rotating at 10 rpm.
[0103] After measuring the Ra values at many locations on the
unfinished AMT Object, it was determined that the high/low Ra
values prior to finishing were 649/787. Following finishing, the
high/low Ra values were determined to be 58/98.
[0104] It will be appreciated that various aspects of the invention
and other features and functions, or alternatives thereof, may be
desirably combined into many other different systems or
applications. Various alternatives, modifications, variations, or
improvements therein may be subsequently made by those skilled in
the art, and these are also intended to be encompassed by the
invention. Although embodiments of the invention have been
described herein, the invention is not limited to such embodiments.
Hence, the present invention is deemed only limited by the appended
claims and the reasonable interpretation thereof.
* * * * *