Powder pre-processing for additive manufacturing

Abstract
The present invention relates to a method for removing moisture from powder to be used in an additive manufacturing process for forming a three-dimensional article through successive fusion of parts of at least one layer of a powder bed provided on a work table, which parts corresponds to successive cross sections of the three-dimensional article, characterized in that said method comprising the steps of: providing at least a first powder tank and at least at least a second powder tank, providing a predetermined amount of powder on a movable table inside said first powder tank, heating the top surface of the powder in said first powder tank to a predetermined temperature interval for removing moisture from said powder, raising said movable table a predetermined distance, moving a predetermined thickness of the powder material from said first powder tank to said second powder tank.
Description
CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage Application, filed under 35 U.S.C. §371, of International Application No. PCT/EP2012/071930, filed Nov. 6, 2012, the contents of which are hereby incorporated by reference in their entirety.


BACKGROUND

Related Field


The present invention relates to a powder pre processing method for additive manufacturing according to the preamble of claim 1.


Description of Related Art


Freeform fabrication or additive manufacturing is a method for forming three-dimensional articles through successive fusion of chosen parts of powder layers applied to a worktable.


An additive manufacturing apparatus may comprise a work table on which said three-dimensional article is to be formed, a powder dispenser, arranged to lay down a thin layer of powder on the work table for the formation of a powder bed, an energy beam for delivering energy to the powder whereby fusion of the powder takes place, elements for control of the energy given off by the energy beam over said powder bed for the formation of a cross section of said three-dimensional article through fusion of parts of said powder bed, and a controlling computer, in which information is stored concerning consecutive cross sections of the three-dimensional article. A three-dimensional article is formed through consecutive fusions of consecutively formed cross sections of powder layers, successively laid down by the powder dispenser.


In additive manufacturing it is important to control the powder distribution. It is desirably to distribute a predefined amount of powder over a predetermined area. This requires a well defined method and apparatus for repeatedly removing a predetermined amount of powder from a powder storage to a powder distributor device. One problem that may arise is that the powder may have more or less of built in moisture. Said moisture may affect the flowability of the powder which in turn may affect the smoothness and thickness of the applied powder layer on the work table. Moisture in powder material for additive manufacturing may also affect the material properties of the final 3-dimensional product in an undesirable way.


BRIEF SUMMARY

An object of the invention is to provide a method which removes the moisture from the powder before starting the additive manufacturing process.


The abovementioned object is achieved by the features in the method according to claim 1.


In a first aspect of the invention it is provided a method for removing moisture from powder to be used in an additive manufacturing process for forming a three-dimensional article through successive fusion of parts of at least one layer of a powder bed provided on a work table, which parts corresponds to successive cross sections of the three-dimensional article. Said method comprising the steps of:

    • a. providing at least a first powder tank and at least at least a second powder tank,
    • b. providing a predetermined amount of powder on a movable table inside said first powder tank,
    • c. heating the top surface of the powder in said first powder tank to a predetermined temperature for removing moisture from said powder,
    • d. raising said movable table a predetermined distance,
    • e. moving a predetermined thickness of the powder material from said first powder tank to said second powder tank.


An advantage of the present invention is that the moisture may be removed before using the powder in an additive manufacturing process eliminating that the moisture in said powder may affect the material properties of the three-dimensional article. Another advantage is that the removal of moisture may take place during pumping vacuum which means that the total manufacturing time may not be extended.


In an example embodiment of the present invention steps c-e may be repeated until a predetermined amount of powder is moved from the first powder tank to said second powder tank.


An advantage of this embodiment is that not more than a predetermined amount of powder than necessary for building a predetermined three-dimensional article is dried, although the first powder tank may comprise more than said predetermined amount of powder.


In another example embodiment said method further comprising the step of providing said first and second powder tank inside an enclosable chamber, which may be a vacuum chamber.


An advantage of this embodiment is that not only the moisture may be removed from the powder material which may affect the final material properties of the three-dimensional article but also the environment may be controlled so that the whole ambient atmosphere around the build and powder tank is set to affect the final properties in a controlled manner.


In one example embodiment a heating of the top surface of the powder in said second powder tank is performed instead of the top surface of the powder in said first powder tank.


An advantage of this embodiment is that the powder may be dried fasted compared to if a top surface of a full powder tank is heated. This is because moisture from powder in the full or partially full powder tank may contaminate the dried powder. In the case of drying a small amount of powder in said second powder container no contamination is performed as soon as the powder is dried.


In one example embodiment of the present invention said temperature is less than a reaction temperature in which the moisture is starting to react chemically with the powder material.


An advantage of said embodiment is that the heating power may be set differently for different materials depending on the tendency to react with the moisture.


In still another example embodiment said temperature is less than a sintering temperature in which powder particles in said powder is starting to sinter together.


When there is no tendency of reaction of the powder material with the moisture the temperature may be increased to a predetermined temperature below the sintering temperature which may further decrease the powder moisture removal time.


In another example embodiment of the present invention said method further comprising the steps of:

    • g. raising a movable table inside said second powder tank a predetermined distance,
    • h. moving a predetermined amount of powder from said second powder tank to a third powder tank,
    • i. distributing said powder on top of a work table inside said third powder tank,
    • j, forming a first layer of said three-dimensional article by fusing said layer of powder provided on said work table in predetermined locations,
    • k, lowering the work table in said third powder tank a predetermined distance,
    • l, repeating steps g-k until the three-dimensional article is finalized.


After having finalized the removal of moisture of a predetermined amount of powder the 3-dimensional article may start to be produced with the powder which does not contain moisture.


In still another example embodiment of the present invention said method further comprising the step of providing a supplementary heating device for heating the top surface of the powder material.


An advantage with said embodiment is the said additional heating device may work alone or in combination with the device for sintering/melting the powder to form the 3-dimensional article. This may further decrease the time for removal of the moisture from the powder material.


In yet another example embodiment of the present invention the fusing of the powder material and heating of the top surface of the powder material for removing moisture is performed by the same high energy beam source.


An advantage of this embodiment is that the energy source may be set in a mode in which the power is distributed into a larger area compared to when said energy source is used for sintering/fusing. By increasing the area of the energy spot on the powder surface may make it possible to further increase to total power of the energy beam and thereby decreasing the time for removal of the moisture from the powder material.


In still another example embodiment of the present invention said method further comprising the step of performing at least a part of said heating step for removing the moisture from the powder while said three-dimensional article is manufactured.


An advantage of this embodiment is that the total manufacturing tame of the three-dimensional time maybe reduced.


In still another example embodiment of the present invention said method further comprising the step of providing a supplementary heating device for heating the top surface of the powder material from above.


An advantage of this embodiment is that the manufacturing time of the three dimensional article may still further be reduced since the heating of the powder is separated and independent from the fusing of powder for producing the three-dimensional article in another powder tank.


In still another example embodiment of the present invention said method further comprising the step of providing a supplementary heating device below said movable table in said second powder tank for heating the powder material.


An advantage of this embodiment is that the heating from below may assist the heating of the top surface and thereby decreasing the time needed for reaching a predetermined temperature.


In still another example embodiment said method further comprising the step of starting said heating of said top surface of said powder material as soon as under pressure in said vacuum chamber is established.


An advantage of this embodiment is that as soon as the vacuum pumps have started moisture generated from the heating of the top surface layer of the powder bed may be removed from the vacuum chamber. In an alternative embodiment said moisture may be transported away from an enclosed chamber by a flow of a suitable gas, such as Argon, Helium or Nitrogen.





BRIEF DESCRIPTION OF THE FIGURES

The invention will be further described in the following, in a non-limiting way with reference to the accompanying drawings. Same characters of reference are employed to indicate corresponding similar parts throughout the several figures of the drawings:



FIG. 1, shows, in a schematic view, an apparatus for producing a three dimensional product according to prior art,



FIG. 2-3, depict, in a schematic view, a first embodiment of a device according to the present invention for removing moisture inside an apparatus for producing a three dimensional product,



FIG. 4-5 depict, in a schematic view, a second embodiment of a device according to the present invention for removing moisture inside an apparatus for producing a three dimensional product,



FIG. 6 depicts, in a schematic view, a third embodiment of a device according to the present invention for removing moisture inside an apparatus for producing a three dimensional product, and



FIG. 7 depicts, in a schematic view, a fourth embodiment of a device according to the present invention for removing moisture inside an apparatus for producing a three dimensional product.





DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

To facilitate the understanding of this invention, a number of terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as “a”, “an” and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as outlined in the claims.


The term “three-dimensional structures” and the like as used herein refer generally to intended or actually fabricated three-dimensional configurations (e.g. of structural material or materials) that are intended to be used for a particular purpose. Such structures, etc. may, for example, be designed with the aid of a three-dimensional CAD system.


The term “electron beam” as used herein in various embodiments refers to any charged particle beam. The sources of charged particle beam can include an electron gun, a linear accelerator and so on.



FIG. 1 depicts an embodiment of a freeform fabrication or additive manufacturing apparatus 21 according to prior art.


Said apparatus 21 comprising an electron beam gun 6; deflection coils 7; two powder hoppers 4, 14; a build platform 2; a build tank 10; a powder distributor 28; a powder bed 5; and a vacuum chamber 20.


The vacuum chamber 20 is capable of maintaining a vacuum environment by means of a vacuum system, which system may comprise a turbomolecular pump, a scroll pump, an ion pump and one or more valves which are well known to a skilled person in the art and therefore need no further explanation in this context. The vacuum system is controlled by a control unit 8.


The electron beam gun 6 is generating an electron beam which is used for melting or fusing together powder material provided on the build platform 2. At least a portion of the electron beam gun 6 may be provided in the vacuum chamber 20. The control unit 8 may be used for controlling and managing the electron beam emitted from the electron beam gun 6. At least one focusing coil (not shown), at least one deflection coil 7, an optional coil for astigmatic correction (not shown) and an electron beam power supply (not shown) may be electrically connected to said control unit 8. In an example embodiment of the invention said electron beam gun 6 generates a focusable electron beam with an accelerating voltage of about 15-60 kV and with a beam power in the range of 3-10 Kw. The pressure in the vacuum chamber may be 10−3 mbar or lower when building the three-dimensional article by fusing the powder layer by layer with the energy beam.


In an alternative embodiment a laser beam may be used for melting or fusing the powder material. In such case tiltable mirrors may be used in the beam path in order to deflect the laser beam to a predetermined position.


The powder hoppers 4, 14 comprise the powder material to be provided on the build platform 2 in the build tank 10. The powder material may for instance be pure metals or metal alloys such as titanium, titanium alloys, aluminum, aluminum alloys, stainless steel, Co—Cr alloys, nickel based superalloys etc.


The powder distributor 28 is arranged to lay down a thin layer of the powder material on the build platform 2. During a work cycle the build platform 2 will be lowered successively in relation to a fixed point in the vacuum chamber. In order to make this movement possible, the build platform 2 is in one embodiment of the invention arranged movably in vertical direction, i.e., in the direction indicated by arrow P. This means that the build platform 2 starts in an initial position, in which a first powder material layer of necessary thickness has been laid down. Means for lowering the build platform 2 may for instance be through a servo engine equipped with a gear, adjusting screws etc.


An electron beam may be directed over said build platform causing said first powder layer to fuse in selected locations to form a first cross section of said three-dimensional article. The beam is directed over said build platform 2 from instructions given by the control unit 8. In the control unit 8 instructions for how to control the electron beam for each layer of the three-dimensional article is stored.


After a first layer is finished, i.e., the fusion of powder material for making a first layer of the three-dimensional article, a second powder layer is provided on said build platform 2. The second powder layer is preferably distributed according to the same manner as the previous layer. However, there might be alternative methods in the same additive manufacturing machine for distributing powder onto the work table.


After having distributed the second powder layer on the build platform, the energy beam is directed over said work table causing said second powder layer to fuse in selected locations to form a second cross section of said three-dimensional article. Fused portions in the second layer may be bonded to fused portions of said first layer. The fused portions in the first and second layer may be melted together by melting not only the powder in the uppermost layer but also remelting at least a fraction of a thickness of a layer directly below said uppermost layer.



FIGS. 2 and 3 depicts schematically a first example embodiment of an inventive setup for removing moisture from the powder inside the vacuum chamber. The powder hoppers 4, 14 and the powder distributor 28 in FIG. 1 have been exchanged with a movable powder hopper 40 and a powder rake 50. To start with a predetermined amount of powder 55 is provided on said worktable 1 inside said build tank 10. Between said worktable 1 and said build platform 2, which is movable, there is provided a predetermined amount of powder forming a powder layer between said build platform 2 and said work table 1. In an alternative embodiment said build platform 2 may be removable and in such embodiment said work table 1 may be unnecessary. The top surface of the powder in said build tank may be heated by a heating device 90 in order to reach a predetermined temperature interval which is high enough for removing moisture but less than a reaction temperature in which the moisture is starting to react with the powder material. Depending on the power and time said heating is taking place, moisture may be removed from different thicknesses, i.e., the longer the time and the higher the power the thicker the layer of powder may be in which the moisture is removed. Moisture is removed as water vapor from the vacuum chamber via the vacuum pumps or via the gas flow.


The heating device may be a supplementary heater for instance a microwave device, IR device, laser device. In another example embodiment the heating device for heating the top surface of the powder in order to remove moisture is the same device as used later on to fuse the powder material in selected location in order to build the three dimensional article in a layer by layer fashion. In the case the device is the same for heating in order to remove moisture and sintering/fusing in order to build the three dimensional article the device may be at least one laser source or at least one electron beam source.


Different materials react more or less easily with the moisture which is generated during the heating. It is therefore necessary to control and set the power and time for different powder materials individually. There is typically a temperature interval in which moisture is generated which can be pumped away from the vacuum chamber without affecting the material properties of the powder material. For Titanium such temperature interval is between room temperature-about +400° C. at the very top surface. At room temperature very small amount of moisture is generated and therefore most of the moisture will remain in the powder if not waiting a very long time. Above approximately +400° C. the moisture may start to react with the titanium powder material and changing the material properties in an undesirable way. In a first embodiment the temperature interval for removing moisture in titanium powder may be between +100° C.-+350° C. In another embodiment the temperature interval for removing moisture in titanium powder may be between +200° C.-+300° C.


Other powder materials may not react at all with the moisture which is generated during the heating process and therefore the temperature can be raised further. In such cases the temperature interval may be from room temperature-predetermined temperature below sintering temperature. In order to make sure that the powder stays in powder form and not sinter into bigger agglomerates a safety interval may be set, which may for instance be 10-100 degrees below the sintering temperature of the particular powder material which is not sensitive for reacting with the moisture. As with Titanium, at room temperature very little moisture is removed per time interval so the temperature interval may typically be between +100° C. or more—predetermined temperature below sintering temperature.


When the heating of the top surface is finalized said build platform 2 and the work table 1 may be raised a predetermined distance. Said distance may for instance be between 0.1-1 mm. The powder rake 50 removes a predetermined thickness of the powder material from said build tank 10 to said powder hopper 40. In an example embodiment said rake removes the same thickness as the distance in which the build platform is raised. In an alternative embodiment a fraction of the height in which the build platform 2 is raised is removed and transferred from the build tank 10 to the powder hopper 40.


After the first layer of powder which is free from moisture has been removed from the build tank 10 to the powder hopper 40 the heating of the new top surface of the powder in said build container may take place. When said new layer is dried from moisture a predetermined amount of powder is removed from the build tank 10 to said powder hopper 40 by increasing the height of the build platform and thereafter using the powder rake 50 for raking over powder form the build tank 10 to the powder hopper 40. This heating and transferring of dried powder from the build tank 10 to the powder hopper 40 is continued until the build tank is free from powder on top of the work table 1. In another example embodiment said heating and transferring of dried powder form the build tank 10 to the powder hopper 40 is continued until a predetermined amount of powder is transferred from the build tank 10 to the powder hopper 40.


In FIG. 3 the powder hopper 40 has been raised in comparison with FIG. 2. In FIG. 2 a top of the build tank 10 and a top of the powder hopper 40 are about the same level. In another embodiment said top of the powder hopper 40 may be lower in comparison with the top of the build tank. In such an embodiment it is still possible to rake powder material from the build tank 10 to the powder hopper. However, in FIG. 3, a powder plate 42 which is arranged on the bottom level of the powder hopper is arranged to be about the same level as the top of the build tank 10. By providing the powder plate 42 at the same level as the top of the build tank makes it possible to rake powder material 55 from the powder hopper 40 provided on said powder plate 42 from said powder plate 42 to said build tank 10 with said powder rake 50. In another example embodiment said powder plate may be arranged at a higher level than the top of the build tank. In such an embodiment it is still possible to rake over material from the powder plate to the build tank. Of course there is no or very small gap between the powder plate 42 and the top of the powder hopper and the build tank in order to let most of the powder being raked from one position to the other and not to fall at undesirable locations. The powder hopper comprises an opening 45 at the bottom which allows for a predetermined amount of powder to fall out of the powder hopper 40. The powder rake may be catching powder material from said fallen out powder from said powder hopper 40 by simply moving into said fallen out powder material. The amount of powder which may be caught by said powder rake may be dependent on the distance said powder rake is moved into the fallen out powder material, the further into the material said powder rake is moved the more material is brought out by it until a predetermined limit which is defined by the size and shape of the powder rake 50.


The principle of removing powder form the fallen out powder material in FIG. 2 and FIG. 3 may work as follows. If a front side of the powder rake is defined to be the side which is first moved in to the fallen out powder material, powder falling on the other side, back side, of the powder rake is the powder material which is to be raked (transferred) from one position to another when the rake is changing direction. The backside of the powder rake is then pushing the material in front of the powder rake and transferring said powder material for from the powder plate 42 to the build tank 10.


The powder which is raked from the powder hopper to the build tank is distributed evenly on top of said work table inside said build tank. Said evenly distribution may be performed with the powder rake 50, but may also be performed with another distribution device such as another rake or a vibration or oscillation mechanism.


A first layer of said three-dimensional article may be formed by fusing said layer of powder provided on said work table in predetermined locations.


The work table may be lowered a predetermined distance in order to allow a further layer of powder material to be provided on the already applied powder layers on said work table. The steps of raking new powder material from the powder hopper to the build tank, distribution of said powder on said work table, fusing of said powder layers on predetermined location and lowering of said work table is repeated until the three dimensional article is finalized.


In an alternative embodiment as depicted in FIG. 4 and FIG. 5 the powder hopper 40 in FIGS. 2 and 3 has been exchanged with an alternative design. The powder hopper 140 in FIGS. 4 and 5 is very similar to the build tank 10. The powder hopper 140 comprises a movable bottom plate 142, which may change its position in the same way as the build platform 2 in the build tank 10. One example embodiment of how said bottom plate may be moved is illustrated in FIG. 1.


Instead of as in FIG. 2 and FIG. 3, where the powder rake is moved into a pile of powder material in order to catch a predetermined amount of powder, the powder rake in FIG. 4 and FIG. 5 is raking powder material from the powder hopper to the build tank and from the build tank to the powder hopper in the same way. If powder material is going to be moved from the build tank 10 to the powder hopper 140 when the powder is dried layer by layer as disclosed above, the build platform is raised a predetermined distance allowing a predetermined amount of powder to be raked from the build tank to the powder hopper 140. In a similar way, when powder material is going to be moved from the powder hopper 140 to the build tank 10, the bottom plate 142 of the powder hopper 140 is raised a predetermined distance allowing a predetermined amount of powder to be raked from the powder hopper 140 to the build tank 10.


In FIGS. 2 and 3 it is only illustrated one powder hopper to the left of the build tank. In an alternative embodiment there may be provided another powder hopper to the right of the build tank 10. In FIG. 4 and FIG. 5 it is also only illustrated one powder hopper to the left of the build tank. In an alternative embodiment there may be provided another powder hopper to the right of the build tank 10.


In FIG. 6 still another example embodiment of the present invention is depicted. In FIG. 6 a first powder container 640, a second powder container 650 and a third powder container 610 are arranged beside each other. The second powder container 640 is arranged between the first and second powder container. Each of said powder container may comprise a movable bottom plate or table 142, 152, 2 which may change its position in the same way as the build platform 2 in the build tank 10. One example embodiment of how said bottom plate may be moved is illustrated in FIG. 1.


A powder rake 50 may be raking powder material from one powder container 640, 650 or 610 to any of the other powder container 640, 650 or 610. A method of drying powder using three powder containers as depicted in FIG. 6 may be performed as follows.


Powder which may comprise moisture is arranged in the first powder container 640. A heating device 90 may be heating the top surface of the powder in said first powder container to a predetermined temperature for allowing moisture to leave the powder. Said movable table 142 is thereafter raised a predetermined amount. The rake is moving a predetermined thickness of the powder from said first powder container to said second powder container. This may continue until a predetermined amount of powder has been moved from said first powder container to said second powder container. A three dimensional article may thereafter be built in said third powder container 610 in a layer by layer fashion by taking predetermined amount of dried powder from said second powder container 650.


In an alternative embodiment said three-dimensional article is built in said third powder container while powder is dried in said second powder container. Here a first heating source 90 may be used for the drying process in said second powder container 650 and a second heating source (not shown) may be used for the heating and fusion process for manufacturing said three-dimensional article in said third powder container. Alternatively, the same heat source is used for heating the powder in said second and third powder container, i.e., the heating source is moved (deflected) back and forth between said second and third powder container.


In still another example embodiment a predetermined amount of powder which may comprise moisture is moved from said first powder container 640 to said second container. Said predetermined amount of powder is distributed evenly over the movable table 152 in said second powder container 650. A heating source is heating said powder in said second powder container to a predetermined temperature interval. Said powder in said second powder container 650 is moved to said third powder container 610 before another predetermined amount of powder is provided to said second powder container 650 from said first powder container 640. This means that in this embodiment no powder drying is taking place in said first powder container 640. Only a small amount of powder may dried in said second powder container 650. When said powder has been dried in said second powder container 650 it is moved to said third powder container 610 for building said three-dimensional article. Said three dimensional-article may be built while another predetermined amount of powder is dried in said second powder container. The drying process and building process may be performed by the same heating source or separate heating sources.



FIG. 7 illustrates yet another example embodiment of the present invention. As in FIG. 6 there are three powder containers, a first powder container 740, a second powder container 750 and a third powder container 710. A predetermined amount of powder which may comprise moisture may provided in said first powder container 740. A predetermined amount of powder is raked by said rake 50 from said first powder container 740 to said second powder container 750 by first raising the movable table 142 in said first powder container 740 a predetermined amount allowing a predetermined amount of powder to be raked off said first powder container. Said predetermined amount of powder in said second powder container is heated from below of its movable table 152 by means of a heating device 170 which may be resistive, IR or any other suitable heating source. When said predetermined amount of powder has been elevated to a predetermined temperature it is raked from said second powder container 750 to said third powder container 710. The three dimensional article is manufactured in said third powder container 710. The heating of a predetermined amount of powder in said second powder container 750 may be performed simultaneously as the three-dimensional article is manufacture din said third powder container 710.


In still another example embodiment said heating device 90 which may be used for manufacturing said three-dimensional article in said third powder container 710 may assist the heating of said powder in said second powder container, i.e., there is a dual heating in said second powder container, a first heating source 170 form below said movable table 152 and a second heating source which is heating the top surface of the powder layer. Instead of using the heating device which is aimed for the manufacturing of the three-dimensional article, still another supplementary heating device may be used for heating the top layer of the powder. The supplementary heating source may be a laser source, e-beam source, IR-source or a resistive source.


In still another example embodiment a complete amount of powder which is necessary for building a predetermined three-dimensional article is dried layer by layer in said second powder container before the manufacturing of said three-dimensional article is started.


The invention is not limited to the above-described embodiments and many modifications are possible within the scope of the following claims. Such modifications may, for example, involve using a different source of energy beam than the exemplified electron beam such as a laser beam. Other materials than metallic powder may be used such as powder of polymers or powder of ceramics.

Claims
  • 1. A method for removing moisture from powder to be used in an additive manufacturing process for forming a three-dimensional article through successive fusion of parts of at least one layer of a powder bed provided on a work table located within a build tank, which parts corresponds to successive cross sections of the three-dimensional article, said method comprising the steps of: providing at least a first powder tank and at least a second powder tank, providing a predetermined amount of powder on a movable table inside said first powder tank,heating the top surface of the powder in said first powder tank to a predetermined temperature for removing moisture from said powder,raising said movable table a predetermined distance,moving a predetermined thickness of the powder material from said first powder tank to said second powder tank, wherein said first powder tank is said build tank for building said three dimensional article,continuing said heating and moving of dried powder from the build tank to the second powder tank until the predetermined amount of powder is moved from the build tank to the second powder tank.
  • 2. The method according to claim 1, wherein said movable table is said work table.
  • 3. The method according to claim 1, further comprising the step of providing said first and second powder tank inside an enclosable chamber.
  • 4. The method according to claim 3, wherein said enclosable chamber is a vacuum chamber.
  • 5. The method according to claim 1, wherein said predetermined temperature is less than a reaction temperature in which the moisture is starting to react with the powder material.
  • 6. The method according to claim 1, wherein said temperature is less than a sintering temperature in which powder particles in said powder is starting to sinter together.
  • 7. The method according to claim 1, further comprising the step of providing a supplementary heating device for heating the top surface of the powder material from above.
  • 8. The method according to claim 1, wherein the fusing of the powder material and heating of the top surface of the powder material for removing moisture are performed by a shared high energy beam source.
  • 9. The method according to claim 8, wherein said supplementary heating device is at least one of a laser or an infrared source.
  • 10. The method according to claim 8, wherein said high energy beam source is an electron beam.
  • 11. The method according to claim 4, further comprising the step of starting said heating of said top surface of said powder material as soon as vacuum conditions in said vacuum chamber are established.
PCT Information
Filing Document Filing Date Country Kind
PCT/EP2012/071930 11/6/2012 WO 00
Publishing Document Publishing Date Country Kind
WO2014/071968 5/15/2014 WO A
US Referenced Citations (118)
Number Name Date Kind
2264968 De Forest Dec 1941 A
2323715 Kuehni Jul 1943 A
3882477 Mueller May 1975 A
4348576 Anderl et al. Sep 1982 A
4401719 Kobayashi et al. Aug 1983 A
4818562 Arcella et al. Apr 1989 A
4863538 Deckard Sep 1989 A
4927992 Whitlow et al. May 1990 A
4988844 Dietrich et al. Jan 1991 A
5167989 Dudek et al. Dec 1992 A
5182170 Marcus et al. Jan 1993 A
5204055 Sachs et al. Apr 1993 A
5247560 Hosokawa et al. Sep 1993 A
5483036 Giedt et al. Jan 1996 A
5511103 Hasegawa Apr 1996 A
5647931 Retallick et al. Jul 1997 A
5753274 Wilkening et al. May 1998 A
5837960 Lewis et al. Nov 1998 A
5876550 Feygin et al. Mar 1999 A
5904890 Lohner et al. May 1999 A
5932290 Lombardi et al. Aug 1999 A
6046426 Jeantette et al. Apr 2000 A
6162378 Bedal et al. Dec 2000 A
6419203 Dang Jul 2002 B1
6554600 Hofmann et al. Apr 2003 B1
6583379 Meiners et al. Jun 2003 B1
6746506 Liu et al. Jun 2004 B2
6751516 Richardson Jun 2004 B1
6764636 Allanic et al. Jul 2004 B1
6811744 Keicher et al. Nov 2004 B2
6815636 Chung et al. Nov 2004 B2
6824714 Türck et al. Nov 2004 B1
7003864 Dirscherl Feb 2006 B2
7020539 Kovacevic et al. Mar 2006 B1
7165498 Mackrill et al. Jan 2007 B2
7204684 Ederer et al. Apr 2007 B2
7291002 Russell et al. Nov 2007 B2
7540738 Larsson et al. Jun 2009 B2
7635825 Larsson Dec 2009 B2
7686605 Perret et al. Mar 2010 B2
7696501 Jones Apr 2010 B2
7713454 Larsson May 2010 B2
7754135 Abe et al. Jul 2010 B2
7799253 Höchsmann et al. Sep 2010 B2
7871551 Wallgren et al. Jan 2011 B2
8021138 Green Sep 2011 B2
8083513 Montero-Escuder et al. Dec 2011 B2
8187521 Larsson May 2012 B2
8308466 Ackelid et al. Nov 2012 B2
8992816 Jonasson et al. Mar 2015 B2
9073265 Snis Jul 2015 B2
9079248 Ackelid Jul 2015 B2
9126167 Ljungblad Sep 2015 B2
9310188 Snis Apr 2016 B2
20020104973 Kerekes Aug 2002 A1
20020152002 Lindemann et al. Oct 2002 A1
20030133822 Harryson Jul 2003 A1
20040084814 Boyd et al. May 2004 A1
20040104499 Keller Jun 2004 A1
20040173496 Srinivasan Sep 2004 A1
20040173946 Pfeifer et al. Sep 2004 A1
20050186538 Uckelmann Aug 2005 A1
20060108712 Mattes May 2006 A1
20060145381 Larsson Jul 2006 A1
20060147332 Jones et al. Jul 2006 A1
20060157892 Larsson Jul 2006 A1
20060180957 Hopkinson et al. Aug 2006 A1
20060284088 Fukunaga et al. Dec 2006 A1
20070175875 Uckelmann et al. Aug 2007 A1
20070182289 Kigawa et al. Aug 2007 A1
20070298182 Perret et al. Dec 2007 A1
20080236738 Lo et al. Oct 2008 A1
20090017219 Paasche et al. Jan 2009 A1
20090152771 Philippi et al. Jun 2009 A1
20100310404 Ackelid Dec 2010 A1
20110133367 Weidinger et al. Jun 2011 A1
20110293770 Ackelid et al. Dec 2011 A1
20110309554 Liska et al. Dec 2011 A1
20110316178 Uckelmann Dec 2011 A1
20120100031 Ljungblad Apr 2012 A1
20120164322 Teulet et al. Jun 2012 A1
20120193530 Parker et al. Aug 2012 A1
20120223059 Ackelid Sep 2012 A1
20120225210 Fruth Sep 2012 A1
20120266815 Brunermer Oct 2012 A1
20130300286 Ljungblad et al. Nov 2013 A1
20140301884 Hellestam et al. Oct 2014 A1
20140308153 Ljungblad Oct 2014 A1
20140314609 Ljungblad et al. Oct 2014 A1
20140314964 Ackelid Oct 2014 A1
20140348691 Ljungblad et al. Nov 2014 A1
20140363327 Holcomb Dec 2014 A1
20140367367 Wood et al. Dec 2014 A1
20150004045 Ljungblad Jan 2015 A1
20150071809 Nordkvist et al. Mar 2015 A1
20150086409 Hellestam Mar 2015 A1
20150088295 Hellestam Mar 2015 A1
20150139849 Pialot, Jr. et al. May 2015 A1
20150151490 Jonasson et al. Jun 2015 A1
20150165524 Ljungblad et al. Jun 2015 A1
20150165525 Jonasson Jun 2015 A1
20150174658 Ljungblad Jun 2015 A1
20150174695 Elfstroem et al. Jun 2015 A1
20150251249 Fager Sep 2015 A1
20150283610 Ljungblad et al. Oct 2015 A1
20150283613 Backlund et al. Oct 2015 A1
20150306819 Ljungblad Oct 2015 A1
20160052056 Fager Feb 2016 A1
20160052079 Ackelid Feb 2016 A1
20160054115 Snis Feb 2016 A1
20160054121 Snis Feb 2016 A1
20160054347 Snis Feb 2016 A1
20160059314 Ljungblad et al. Mar 2016 A1
20160279735 Hellestam Sep 2016 A1
20160282848 Hellestam Sep 2016 A1
20160303687 Ljungblad Oct 2016 A1
20160307731 Lock Oct 2016 A1
20160311021 Elfstroem et al. Oct 2016 A1
Foreign Referenced Citations (56)
Number Date Country
2860188 Jun 2006 CA
101635210 Jan 2010 CN
201693176 Jan 2011 CN
19952998 May 2001 DE
20305843 Jul 2003 DE
102005014483 Oct 2006 DE
202008005417 Aug 2008 DE
102007018601 Oct 2008 DE
102007029052 Jan 2009 DE
102008012064 Sep 2009 DE
0289116 Nov 1988 EP
0322257 Jun 1989 EP
0688262 Dec 1995 EP
1418013 May 2004 EP
1466718 Oct 2004 EP
1683593 Jul 2006 EP
1721725 Nov 2006 EP
1952932 Aug 2008 EP
2011631 Jan 2009 EP
2119530 Nov 2009 EP
2281677 Feb 2011 EP
2003245981 Sep 2003 JP
524467 Aug 2004 SE
WO 9308928 May 1993 WO
WO 9612607 May 1996 WO
WO 9737523 Oct 1997 WO
WO 0181031 Nov 2001 WO
WO 0185386 Nov 2001 WO
WO 0208653 Jan 2002 WO
WO 2004007124 Jan 2004 WO
WO 2004043680 May 2004 WO
WO 2004054743 Jul 2004 WO
WO 2004056511 Jul 2004 WO
WO 2006091097 Aug 2006 WO
WO 2006121374 Nov 2006 WO
WO 2007112808 Oct 2007 WO
WO 2007147221 Dec 2007 WO
WO 2008013483 Jan 2008 WO
WO 2008057844 May 2008 WO
WO 2008125497 Oct 2008 WO
WO 2008147306 Dec 2008 WO
WO 2009000360 Dec 2008 WO
WO 2009072935 Jun 2009 WO
WO 2009084991 Jul 2009 WO
WO 2010095987 Aug 2010 WO
WO 2011008143 Jan 2011 WO
WO 2011030017 Mar 2011 WO
WO 2011060312 May 2011 WO
WO 2012102655 Aug 2012 WO
WO 2013098050 Jul 2013 WO
WO 2013098135 Jul 2013 WO
WO 2013159811 Oct 2013 WO
WO 2013167194 Nov 2013 WO
WO 2013178825 Dec 2013 WO
WO 2014095200 Jun 2014 WO
WO 2014095208 Jun 2014 WO
Non-Patent Literature Citations (19)
Entry
Cheah, Chi-Mun, et al., “Automatic Algorithm for Generating Complex Polyhedral Scaffold Structure for Tissue Engineering”, Tissue Engineering, 2004, pp. 595-610, vol. 10, No. 3/4, XP002691483.
European Search Report dated Feb. 16, 2012, for corresponding Application No. EP07852089.7.
Guibas, Leonidas J., et al., “Randomized Incremental Construction of Delaunay and Voronoi Diagrams”, Algorithmica, Jun. 1992, pp. 381-413, vol. 7, Issue 1-6, Springer-Verlag, New York.
International Preliminary Examining Authority (IPEA), Second Written Opinion for International Application No. PCT/EP2012/076025, mailed Dec. 4, 2013, 4 pages European Patent Office, Germany.
International Preliminary Examining Authority, International Preliminary Report on Patentability for International Application No. PCT/EP2012/076025, including Applicant's Sep. 10, 2013 Response to the ISA's May 17, 2013 Written Opinion and Applicant's Jan. 14, 2014 Response to the IPEA's Second Written Opinion, mailed Apr. 4, 2014, 15 pages, European Patent Office, Germany.
International Preliminary Examining Authority, International Preliminary Report on Patentability for International Application No. PCT/EP2012/074383, including Applicant's Sep. 6, 2013 Reply to ISA's Feb. 27, 2013 Written Opinion, mailed Jan. 20, 2014, 16 pages, European Patent Office, The Netherlands.
International Preliminary Report on Patentability, dated Nov. 27, 2009, of corresponding international application No. PCT/SE2007/001084.
International Search Report dated Apr. 9, 2010 for Application No. PCT/SE2009/050901.
International Search Report dated Sep. 17, 2008 for Application No. PCT/SE2008/000007.
International Search Report mailed Sep. 2, 2008 of corresponding international application No. PCT/SE2007/001084.
International Searching Authority (ISA), International Search Report and Written Opinion for International Application No. PCT/EP2012/076025, mailed May 17, 2013, 11 pages, European Patent Office, The Netherlands.
International Searching Authority, International Search Report and Written Opinion for International Application No. PCT/EP2012/074383, mailed Feb. 27, 2013, 10 pages, European Patent Office, The Netherlands.
International Searching Authority, International Search Report for International Application No. PCT/SE2011/050093, mailed Oct. 20, 2011, 5 pages, The Swedish Patent and Registration Office, Sweden.
Weigel, TH. , et al., “Design and Preparation of Polymeric Scaffolds for Tissue Engineering,” Expert Rev. Med. Devices, 2006, pp. 835-851, vol. 3, No. 6, XP002691485.
Yang, et al., “The Design of Scaffolds for Use in Tissue Engineering, Part II, Rapid Prototyping Techniques”, Tissue Engineering, 2002, pp. 1-11, vol. 8, No. 1, XP002691484.
International Searching Authority, International Search Report for International Application No. PCT/EP2012/057470, mailed Jan. 24, 2013, 1 page, European Patent Office, The Netherlands.
International Searching Authority, International Search Report for International Application No. PCT/EP2012/058733, Mar. 5, 2013, 4 pages, European Patent Office, The Netherlands.
International Searching Authority, International Search Report and Written Opinion for International Application No. PCT/EP2012/071930, Aug. 5, 2013, 8 pages, European Patent Office.
International Preliminary Examining Authority, International Preliminary Report on Patentability, including Applicant's submittal of Jan. 15, 2015 amended claims, for International Application PCT/EP2012/071930, Feb. 6, 2015, 10 pages, European Patent Office.
Related Publications (1)
Number Date Country
20150290710 A1 Oct 2015 US