U.S. patent application number 15/661036 was filed with the patent office on 2017-11-09 for device of generatively manufacturing three-dimensional objects with insulated building field.
This patent application is currently assigned to EOS GmbH Electro Optical Systems. The applicant listed for this patent is EOS GmbH Electro Optical Systems. Invention is credited to Andreas Baumann, Thomas Mattes, Jochen Philippi.
Application Number | 20170320265 15/661036 |
Document ID | / |
Family ID | 43480996 |
Filed Date | 2017-11-09 |
United States Patent
Application |
20170320265 |
Kind Code |
A1 |
Baumann; Andreas ; et
al. |
November 9, 2017 |
Device of Generatively Manufacturing Three-Dimensional Objects with
Insulated Building Field
Abstract
The present invention relates to a device for generatively
manufacturing a three-dimensional object (3), comprising: a frame
(1) defining a building field (6) at an upper portion (2) thereof;
a plate (12) which connects the frame (1) with a housing (100) of
the device; a support (5) which is arranged in the frame (1) and
vertically movable by a lift mechanics (4) at least below the
building field (6); a radiation device (7) which generates an
energetic beam (8, 8') which is focused by a deflection means (9)
to arbitrary points in the building field (6), so as to selectively
sinter or melt a powdery material (11) which is present in the
building field (6); a coater (10) for applying a layer of powdery
material (11) onto the support (5) or a previously applied layer of
the powdery material (11). A thermal insulation (13) is arranged
between the frame (1) and the plate.
Inventors: |
Baumann; Andreas;
(Grafelfing, DE) ; Philippi; Jochen; (Grafelfing,
DE) ; Mattes; Thomas; (Gilching, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EOS GmbH Electro Optical Systems |
Krailling |
|
DE |
|
|
Assignee: |
EOS GmbH Electro Optical
Systems
Krailling
DE
|
Family ID: |
43480996 |
Appl. No.: |
15/661036 |
Filed: |
July 27, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12982491 |
Dec 30, 2010 |
9744723 |
|
|
15661036 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 64/371 20170801;
B29C 64/245 20170801; B29C 64/25 20170801; B29C 64/153 20170801;
B29C 64/295 20170801; B29C 64/255 20170801; B33Y 30/00 20141201;
B22F 3/1055 20130101; Y02P 10/25 20151101; Y02P 10/295
20151101 |
International
Class: |
B29C 64/153 20060101
B29C064/153; B33Y 30/00 20060101 B33Y030/00; B29C 64/295 20060101
B29C064/295; B22F 3/105 20060101 B22F003/105 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 5, 2010 |
DE |
102010004035.5 |
Claims
1. A device for generatively manufacturing a three-dimensional
object, comprising: a housing; an exchangeable frame that is
modularly insertable into and removable from the housing, that
defines a building field by an upper portion of the exchangeable
frame, and that surrounds the building field on all sides of the
building field when inserted into the housing; a plate that is
arranged in parallel to a plane of the building field where the
plane defines a build surface, the plate surrounding the
exchangeable frame on all sides of the exchangeable frame, the
plate being in contact with the housing; a support arranged in the
exchangeable frame and vertically movable by a lift mechanism; a
radiation device that generates an energetic beam that is focused
onto the building surface by a deflector so as to selectively
sinter or melt a powdery material present in the building field; a
coater for applying a layer of a powdery material onto the support
or a previously applied layer of the powdery material; and a
thermal insulation arranged between the exchangeable frame and the
plate, wherein a gap is formed between the exchangeable frame and
the plate and the gap surrounds the exchangeable frame on all sides
of the exchangeable frame, the thermal insulation is located in the
gap between the frame and the plate, the gap is sealed at a bottom
of the gap by a flexible seal, and the gap can be filled with
powdery material by the coater, and the gap is delimited on one
side by a sidewall of the plate and on the other side by a sidewall
of the frame, such that when the gap is substantially filled with
powdery material by the coater, the powdery material is immediately
adjacent the exchangeable frame on one side and immediately
adjacent the plate on the other side so that the plate is in
contact with the exchangeable frame only via the flexible seal and
the powdery material, the powdery material comprising the thermal
insulation.
Description
[0001] The present invention relates to a device for generatively
manufacturing a three-dimensional object.
[0002] EP 0 764 079 B1 describes a known laser sintering device
comprising a frame which surrounds at its upper portion a building
field; a support which is arranged within the frame and vertically
movable at least below the building field by a lift mechanics; a
radiation device generating an energetic beam which is focused on
arbitrary points within the building field by a deflection device
so as to selectively sinter or melt a powdery material which is
present in the building field; a coater for applying a layer of
powdery material onto the support or a previously applied layer of
the powdery material. The laser sintering device has a heating
means which serves to heat-on a powdery layer, which has been
applied by a coater, to a pre-temperature required for the
sintering process by means of the laser beam. In spite of the use
of the heating means, inhomogeneous temperatures may occur in the
building field, whereby the mechanical properties of the objects
can be inhomogeneous.
[0003] It is the object of the present invention to provide a
device for generatively manufacturing a three-dimensional object,
by which the mechanical properties of the manufactured objects can
be improved.
[0004] This object is achieved by the device for generatively
manufacturing a three-dimensional object having the features of
claim 1. Advantageous further developments are subject of the
dependent claims.
[0005] The invention has the advantage that the frame is thermally
insulated from the housing of the device by the insulation, so that
less heat escapes from the building field to the housing of the
device. Advantageously, the temperature gradients, in particular in
the area of the building field, are thereby reduced. By
systematically reducing the heat loss, the temperature fall in the
peripheral area of the building field can positively be affected,
so that an adjustment to different geometries of the work pieces
and different kinds of powders are possible. For example, the
effectively usable area within the building field and the shrinkage
properties of the objects to be manufactured can be improved.
[0006] Further features and aims of the invention can be gathered
from the description of embodiments on the basis of the attached
drawings. In the Figures show:
[0007] FIG. 1 a schematic view of a device for manufacturing a
three-dimensional object according to a first embodiment of the
present invention;
[0008] FIG. 2 a schematic view of a thermal insulation at a
building field of the device according to the first embodiment;
[0009] FIG. 3 a schematic view of a thermal insulation at a
building field of the device according to a second embodiment of
the present invention;
[0010] FIG. 4 a schematic view of a device for manufacturing a
three-dimensional object according to a modification of the first
embodiment of the present invention.
[0011] FIG. 1 shows schematic view of a device for manufacturing a
three-dimensional object 3 according to a first embodiment of the
present invention which is exemplarily embodied as laser sintering
device.
[0012] The laser sintering device comprises a frame 1 which opens
at the top and comprises therein a support 5 which is movable in
the vertical direction and supports the three-dimensional object 3
to be manufactured. The frame 1 surrounds at its upper portion 2 a
building field 6. Preferably, the frame 1 and the support 5 form an
exchangeable replacement frame which can be removed from the laser
sintering device. The support 5 is connected to a lift mechanics 4,
by which it is moved in the vertical direction at least below the
plane of the building field 6, such that the upper side of the
powdery layer, which is to be solidified, lies in the plane of the
building field 6. As the plane of the building field, a plane is
considered here, in which the upper periphery of the upper portion
2 lies.
[0013] Further, a coater 10 for applying a layer of a powdery
material 11 is provided. As powdery material 11, all laser
sinterable powders can be used, such as laser-sinterable polymers
such as polyaryleetherketone, polyarylethersulfane, polyamide,
polyester, polyether, polyolefine, polystyrene,
polyphenylensulfide, polyvinylidenfluoride, polyphenylenoxyde,
polyimide, their copolymers and blends which include at least one
of the preceding polymers; however the selection is not restricted
to the above-mentioned polymer and copolymer. Polyaryleetherketone,
which are particularly suitable, can be selected from the group of
polyetheretherketone (PEEK), polyetherketoneketone (PEKK),
polyetherketone (PEK), polyetheretherketoneeketone (PEEKK) and
polyetherketoneetherketoneeketone (PEKEKK) and
polyetheretheretherketone (PEEEK) as well as their copolymers, in
particular with polyurylethersulfone as well as their blends
thereof can be selected which includes at least one of the
above-mentioned polymers. Polyamide-polymer or copolymer and the
blends thereof, which are particularly suitable, can be selected
from the group which consists of polyamide 6/6T,
polyamideelastomere such as polyetherblockamide such as PEBAX-based
materials, polyamide 6, polyamide 66, polyamide 11, polyamide 12,
polyamide 612, polyamide 610, polyamide 1010, polyamide 1212,
polyamide PA6T/66, PA4T/46 and copolymers which include at least
one of the above-mentioned polymers. Suitable polyester polymer or
copolymer can be selected from polyalkylentererephtholate (for
example PET, PBT) and their copolymers. Suitable
polyolefinepolymere or copolymer can be selected from a group of
consisting of polyethylene and polypropylene. Suitable
polystyrenepolymer or copolymer can be selected from a group
consisting of syndiotactic and isotactic polysterene. Further,
compound powder of polymer can be used, which include fillers
and/or additives in addition to the corresponding polymer,
copolymer or blend. Such fillers are for example fibers, such as
coal or glass-fibers and carbon-nano tubes, fillers having a low
aspect ratio such as glass-beads or aluminum grains, mineral
fillers, such as titan dioxide. The additives can be, amongst
others, process assisting means such as ripple-assisting means of
the aerosol-series (such as Aerosil 200), functional additives such
as heat stabilisators, oxidation stabilisators, color pigments
(such as graphite and soot) and fire-proof means (such as
organophosphate, polybromeneated hydrocarbon). As powdery material
11, also metals, ceramics, molding sand and compound materials can
be used. As metal-containing powdery material, arbitrary metals and
their alloys as well as mixtures of metallic components or
non-metallic components can be considered.
[0014] The coater 10 is moved in a predetermined height above the
building field 6, such that the layer of the powdery material 11
lies in a defined height above the support 5 and/or above the last
solidified layer. The device further comprises a radiation device
in the shape of a laser 7 which generates a laser beam 8, 8' which
is focused to arbitrary points in the building field 6 by a
deflection device 9. Thereby, the laser beam 8, 8' can selectively
solidifying the powdery material 11 at locations corresponding to
the cross-section of the object 3 to be manufactured.
[0015] The laser sintering device may comprise a heating device
(not shown) above the building field 6 in order to pre-heat a newly
applied powdery layer to a temperature close to the
process-temperature required for the solidification of the powdery
material 11.
[0016] Reference sign 100 designates a housing, in which the frame
1, the support 5, and the coater 10 are arranged. In the following,
the inside of the housing 100 is referred as building space.
Preferably, the housing is gas-tightly formed and has in the upper
area an inlet for introducing the laser beam 8, 8'. Preferably, an
inert gas is introduced into the housing 100. Further, a control
unit 40 is provided, by which the device is controlled in a
coordinated manner to perform the building process and to control
the application of energy by the laser 7.
[0017] In the device, a plate 12 is provided which is in contact
with the frame 1, for example at the upper portion 2 thereof, and
with a housing of the device.
[0018] The device has a thermal insulation 13 which is arranged
between the frame 1 and the plate 12. The thermal insulation 13 is
preferably arranged in the plane of the building field 6, but it
can also be located below or above the plane of the building field
6. FIG. 2 shows that the insulation 13 is integrally formed in the
plate 12 and circumferentially arranged around the frame 1. The
frame 1 is thermally insulated from the housing 100 of the device
by the insulation 13, so that less heat escapes from the building
field 6 to the housing 100 and to the building field environment
surrounding the building field. Advantageously, temperature
gradients, in particular in the peripheral area of the building
field 6, are thereby reduced. The term "building field environment"
hereby designates an area which lies in the plane of the building
field 6 within the housing 100 and laterally adjoins to the
building field 6 and extends between the building field 6 and the
housing 100.
[0019] The insulation 13 can releasable be mounted to the plate 12.
Thereby, it is possible to form the insulation 13 as an
exchangeable insert.
[0020] FIG. 3 shows a second embodiment of the thermal insulation
13. This insulation 13 has different heat conductivities at
different circumferential positions of the frame 1. The insulation
13 extends horizontally outward from the frame 1, wherein the
dimension of the horizontal extension changes at different
circumferential positions of the frame 1. Preferably, the dimension
of the horizontal extension at the corners of the frame 1 is larger
than at other circumferential positions of the frame 1. Thereby,
the heat loss is variable along the circumference of the building
field 6, and the heat loss can be reduced in particular at the
corners of the frame 1. By systematically reducing the heat loss,
the temperature fall can positively be affected in the peripheral
area of the building field 6, so that adjustments to different
workpiece geometries and different kinds of powders are possible.
For example, the effectively usable area of the building field 6
and the shrinking properties of the object 3 to be manufactured can
be improved.
[0021] For example, to achieve different specific heat
conductivities, the insulation 13 can contain different materials,
which have different specific heat conductivities, at different
circumferential positions of the frame 1. According to the task,
different insulations 13, which have different dimensions of the
horizontal extension and/or different materials, can be mounted to
different circumferential positions of the frame 1 at the plate
12.
[0022] It is conceivable that the insulation 13 consists of an
insulation material with mechanical load capacity, an insulation
material without mechanical load capacity or a combination
thereof.
[0023] The advantage of an insulation material with mechanical load
capacity lies in that this can be directly fixed to the frame
without providing a specific frame or bracket. Furthermore, the
insulation material with mechanical load capacity can be easily
cut, and it is easily exchangeable. However, compared with an
insulation material without mechanical load capacity, the
insulation effect is generally smaller. An example of an insulation
material with mechanical load capacity is the material DOTHERM or
DOGLAS of the company DOTHERM GmbH & Co. KG. However, the
invention is not restricted to this material.
[0024] The advantages of an insulation material without mechanical
load capacity compared with an insulation material with mechanical
load capacity are an improved insulation effect as well as the
cheaper material costs and a better availability. However, compared
with the insulation material with mechanical load capacity, the
insulation material without mechanical load capacity must generally
be provided with a suitable frame, bracket or housing. Examples of
an insulation material without mechanical load capacity are
glass-fiber webs, glass-fiber mats or the material PROMALIGHT of
the company Promat GmbH. However, the invention is not restricted
to these materials.
[0025] The insulation 13 can consist of a heat-resistant synthetic
plastic. Examples of suitable synthetic plastics are polystyrene,
polyimide, polyetherimide, polybenzimidazole (PBI), PUR, aromatic
polyamide, polyacrylnitrile. By mixing-up with phenole-formaldehyde
resin, an improved temperature stability can be achieved.
[0026] Moreover, it is conceivable to use the powdery material 11
itself, which is used for building, as insulation material. In this
case, the thermal insulation can be realized by a gap (not shown)
between the frame 1 and the plate 12, wherein the gap is closed
and/or powder-tightly sealed at the bottom. Such sealing of the gap
can be achieved by use of a flexible seal. When the coater 10
applies a layer of the powdery material 11 onto the support 5 or a
previously applied layer of the powdery material 11, the gap is
thereby filled with the powdery material 11. The powdery material
11 in the gap has generally an excellent thermal insulation
effect.
[0027] During operation of the device, the support 5 is moved
downwards in a first step by the lift mechanics 4 as far as the
upper side thereof lies below the plane of the building field 6 by
the desired thickness of the first powdery layer. Then, a first
layer of the powdery material 11 is applied and smoothened onto the
support 5 by the coater 10.
[0028] If the heating device is provided, the temperature of the
uppermost powdery material 11 can globally be pre-heated to a few
.degree. C. below the process temperature required for the
solidification by the heating device. Thereafter, the control unit
40 controls the deflection means 9 such that the deflected laser
beam 8, 8' selectively impacts on the locations of the layer of the
powdery material 11 which shall be solidified. Thereby, the powdery
material 11 is solidified and/or sintered at these locations, so
that the three-dimensional object 3 is generated here.
[0029] In a next step, the support 5 is lowered by the lift
mechanics 4 by the desired thickness of the next layer. By the
coater 10, a second powdery material layer is applied, smoothened
and selectively solidified by means of the laser beam 8, 8'. These
steps are repeated until the desired object 3 is manufactured.
[0030] By the thermal insulation 13, the temperature gradients, in
particular in the peripheral area of the building field 6, can
thereby be reduced.
[0031] The device according to the invention is particularly
applicable in laser sintering processes, where the temperature of
the uppermost powdery layer in the building field 6 is pre-heated
by a separate heat device to few .degree. C. below the
process-temperature required for the solidification, wherein the
additional radiation by the laser beam 8' provides for a further
application of energy in order to solidify the powdery material.
This particularly applies in the use of powdery synthetic plastic
material.
[0032] The scope of protection is not restricted to the described
embodiments, but it includes further changes and modifications,
provided that they fall within the scope as defined by the attached
claims.
[0033] For example, the device according to the invention is not
only applied to laser sintering, but to all powder-based generative
methods, where a material and/or powdery material is used in each
layer to be applied, wherein the material is solidified by
energetic radiation. The energetic radiation must not necessarily
be a laser beam 8', but it can also be an electron beam, for
example.
[0034] In the first embodiment according to FIG. 1, the thermal
insulation 13 is substantially arranged in the plane of the
building field 6 which has been defined by the upper periphery of
the upper portion 2 of the frame 1. However, the insulation 13 has
not to be arranged at an outer circumference of the frame 1, as it
is the case in the first embodiment according to FIG. 1. FIG. 4
shows a modification, where the thermal insulation 13 is arranged
above the upper portion 2 of the frame 1 and preferably in contact
therewith. When the frame 1 is embodied as replacement frame, the
upper portion 2 of the replacement frame 1 can abut from the bottom
to the insulation 13. Advantageously, a good sealing between the
replacement frame 1 and the insulation 13 is thereby achieved. The
"plane of the building field" is not anymore defined by the upper
periphery of the portion 2 in this embodiment, but by the upper
side of the plate 12 which lies in this plane.
[0035] Further, the insulation 13 has not to completely surround
the frame 1 in all embodiments, but it can be arranged only at some
locations of the circumference of the frame 1.
[0036] Furthermore, it is advantageous when the insulation 13 is
arranged in close proximity of the frame 1 and directly adjoins
thereto, for example.
* * * * *