Powder application device for a system to manufacture workpieces by applying powder layers with electromagnetic radiation or particle radiation

p0001The present invention relates to a powder coating apparatus which is designed for use in a plant for production of three-dimensional workpieces by applying of powder layers with electromagnetic radiation or particle radiation. The invention further relates to a body vested with such powder coater plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation, in particular a Laserschmelz- or laser sintering system.

p0002The selective laser melting or laser sintering is a generative layer manufacturing to complex-shaped three-dimensional workpieces can be processed by the powdery, in particular metallic and / or ceramic raw materials. For this purpose a Rohs is toffpulverschicht applied to a support and ortselektiv applied depending on the desired geometry of the workpiece to be created by laser radiation. The penetrating into the powder layer laser radiation causes heating and therefore a fusion or sintering of the raw material powder particles. Then successively more raw material powder layers are applied to the already laser treated layer to the support until the workpiece has the desired shape and size. Selective laser melting or laser sintering can be used in particular for the production of prototypes, tools, spare parts or medical prostheses, such as dental or orthopedic prostheses based on CAD ​​data.

p0003One of the <patcit id="pcit0001" dnum="EP1793979A1"><text>EP 1793979 A1</text></patcit> known plant for the production of molded bodies from pulverulent raw materials by selective laser melting process includes a space in which a plurality of carriers arranged for the molded body. A powder layer preparation device comprises a powder reservoir holder which can be reciprocated by means of a spindle drive on the carrier. In the powder reservoir holder are several, the individual carriers associated insertion openings formed record serving as the powder reservoir swap bodies. On her the carriers underside facing the swap bodies each have a powder discharge port, can be applied by the powder of the interchangeable containers to the carrier. Furthermore, swap bodies are each provided with Pulverabstreifelementen that serve that applied to the carrier layer of powder to flatten during the movement of the powder reservoir holder on the carrier and level to a desired level.

p0004The invention is directed to an object to provide a powder coating apparatus for a plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation, the processing of various raw material powder allows for the production of a workpiece. Furthermore, the invention is directed to an object to provide a body vested with such powder coater plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation, in particular a Laserschmelz- or laser sintering system.

p0005This object is solved by a powder coating apparatus with the features of claim 1 and a plant for manufacturing work pieces by impinging powder layers with electromagnetic radiation or particle radiation having the features of claim 12.

p0006A powder coating apparatus according to the invention for use in a plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation, in particular a Laserschmelz- or laser sintering plant comprises a powder feed opening through which the plant to be processed raw material powder is fed into the powder coater. The raw material powder may be a plastic powder, a ceramic powder, a metallic powder and / or any other powder by any suitable particle size or particle size distribution. Preferably, powders are processed with a grain size &lt;200 microns. Further, the powder application device according to the invention comprises a powder chamber, which serves on the powder supply port in the powder application device supplied and incorporated aufzubringendes raw material powder to a carrier of the plant for manufacturing work pieces by impinging powder layers with electromagnetic radiation or particle radiation. The powder room can be dimensioned so that it can accommodate the entire raw material powder required for the production of a workpiece. Alternatively, however, the powder chamber can be carried out also small and the powder feed opening can be connected to a corresponding Pulvernachführvorrichtung for tracking of powder in the powder chamber of the powder applicator. The Pulvernachführung can, as required, be carried out continuously or discontinuously.

p0007The powder chamber of the powder coating apparatus according to the invention comprises at least two separable powder chambers. Each powder chamber is provided with a Pulverauslassöffnung for delivery of raw powder from the powder compartment to the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation. It is understood that the Pülverraum the powder coating apparatus according to the invention may be divided into any number of powder chambers. However, the powder chambers must be such mutually sealed to prevent the entry of raw material powder from a powder chamber can be reliably prevented in another powder chamber. The Pulverauslassöffnungen the powder chambers are preferably arranged in the region of the carrier of the plant for the production of workpieces by application of powder layers facing with electromagnetic radiation or particle bottom of the powder chambers so that a gravity-driven powder removal from the powder chambers to the carrier of the plant for the production of workpieces by applying of powder layers with electromagnetic radiation or particle radiation is possible. Into the powder chambers of the powder application device according to the invention, different raw material powders may be added. This makes it possible to process different raw material powder in the manufacture of a workpiece by selectively applying of powder layers with electromagnetic radiation or particle radiation, in particular laser melting or selective laser sintering.

p0008The powder chamber of the powder coating apparatus according to the invention may comprise several independently formed powder chambers. For example, the powder chambers can be carried out in a modular design and is releasably connectable to each other. The powder coating device may then be operated in each case with a desired number of powder chambers. Alternatively, however, the powder application device according to the invention may also comprise a powder room, in which several, for example two, by means of a partition wall are provided separate powder chambers. The powder coating device may be designed relatively compact and lightweight. The partition must be in particular in the vertical direction do not extend through the entire powder room of the powder coating apparatus. Instead, the partition wall must only be designed so that it prevents the ingress of powder from a powder chamber into another powder chamber.

p0009The powder coating apparatus may, in particular if the powder chamber is formed by separate from each other by a partition powder chambers have only one powder supply opening, can be fed through the raw material powder into the powder chambers of the powder chamber. Alternatively, it is also conceivable to provide a plurality of powder feed ports, which are respectively associated with the separate powder chambers, allowing the selective supply of raw material powder in this powder chambers. Such a configuration of the powder application device according to the invention is advantageous when a particularly clean separation of the processed using the powder raw material powder application device is desired or required.

p0010In operation, the powder coating apparatus according to the invention, ie when using the powder coating apparatus in a plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation, the powder coating apparatus can be used to by a trained, for example in the form of a spindle drive or the like driving means linearly over the support of the system production of workpieces by applying of powder layers with electromagnetic radiation or particle radiation can be reciprocated so as to apply to the surface of the carrier or one arranged on the support the workpiece raw material powder layers, which are subsequently to the layered construction of the workpiece ortselektiv with electromagnetic radiation or particle radiation, in particular laser radiation can be applied. To control the raw material powder layer structure on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation the powder chambers of the powder application device is preferably each assigned a device for controlling the powder dissipation through the Pulverauslassöffnungen the powder chambers. Preferably, such a control device is provided for each powder chamber of the powder coating apparatus. The powder coating device then allows a selective application of the different material powder on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation.

p0011The means for controlling the powder dissipation by Pulverauslassöffnung the powder chamber may comprise an outlet section of a Pulverauslassöffnung controlling closure device and / or a conveyor for conveying accommodated in the powder chamber material powder toward the Pulverauslassöffnung. The means for controlling the powder dissipation by Pulverauslassöffnung the powder chamber is preferably designed such that it enables a dosage of votes on the Pulverauslassöffnung from the powder chamber raw powder. In particular, the means for controlling the powder discharge may be established by the Pulverauslassöffnung the powder chamber to control the mass flow of the votes on the Pulverauslassöffnung from the powder chamber raw powder in stages or continuously.

p0012For example, the means for controlling the powder dissipation are formed by the Pulverauslassöffnung the powder chamber by a feed shaft during operation raw material powder from the powder chamber in the direction of Pulverauslassöffnung and by Pulverauslassöffnung on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle promotes. The conveyor shaft is preferably positioned so that it closes in a resting state, ie in a non-driven state, Pulverauslassöffnung the powder chamber. The conveyor shaft can be driven by a suitable drive means always the same rotational direction or in alternating directions of rotation. Preferably, the position of Pulverauslassöffnung is selected relative to the position of the feed shaft, depending on the desired driving direction of the conveyor shaft. When the powder coating apparatus includes a plurality of conveyor shafts, all conveying shafts can be driven in the same direction of rotation. Alternatively, it is also possible to drive a portion of the conveyor shafts in one direction and a portion of the conveyor shafts in an opposite rotational direction.

p0013During operation of the powder application device according to the invention the means for controlling the powder discharge through the Pulverauslassöffnungen the powder chambers by an electronic control unit depending on the desired structure of the produced by applying of powder layers with electromagnetic radiation or particle radiation, in particular laser melting or selective laser sintering workpiece can be controlled. For example, the devices can be controlled to control the powder dissipation through the Pulverauslassöffnungen the powder chambers so that successively layers of different raw material powders to the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation or a workpiece layer already produced are applied. Additionally or alternatively, a ortselektive control the means for controlling the powder dissipation through the Pulverauslassöffnungen the powder chambers is conceivable that the means for controlling the powder dissipation through the Pulverauslassöffnungen the powder chambers can be controlled so that different regions of the carrier of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation and the workpiece layer already produced are covered with a layer of various raw materials powders.

p0014The powder coating apparatus according to the invention preferably further comprises a smoothing slider which is so positioned relative to a Pulverauslassöffnung a powder magazine that he, ie when the powder application device via the carrier of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle moves during operation of the powder coater is covered by a marketing Pulverauslassöffnung on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle sweeps applied raw material powder layer to smooth the raw material powder layer and level to a desired level. In other words, the leveling slider is preferably so positioned relative to a Pulverauslassöffnung a powder chamber such that it is positioned relative to a movement direction of the powder application device in operation behind the Pulverauslassöffnung. This allows the leveling slider are performed on the raw material powder layer, which is applied by the Pulverauslassöffnung on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation.

p0015With appropriate positioning of the smoothing slider and corresponding operation of the powder coating device it may be sufficient to provide the powder coating apparatus with only one leveling slider. For example, the leveling slider be positioned behind all Pulverauslassöffnungen the powder application device when the powder application device is moved linearly in a first direction over the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation. Since the leveling slider can then be positioned inevitably at a movement of the powder application device in a first direction opposite to the second direction only in front of the Pulverauslassöffnungen, however, it is then necessary to close the Pulverauslassöffnungen the powder application device during the movement of the powder coating apparatus in the second direction, that is, the as "deadhead" provide movement of the powder coating apparatus in the second direction. Such a configuration and operation of such a powder coating apparatus according to the invention is useful when the powder application device should be as simple as possible and necessary for the workpiece manufacturing cycle times of only minor importance.

p0016A powder coating apparatus which can be operated without "emptying", comprises a powder supply port, a powder room for accommodating a carrier of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle aufzubringendem raw powder and a powder room with at least one powder compartment. If the powder room only comprises a powder chamber, the powder chamber is provided with two separate Pulverauslassöffnungen for delivery of raw powder from the powder chamber and arranged a leveling slider between the two Pulverauslassöffnungen. Thereby the leveling slider is based on a moving direction of the powder coating apparatus in operation always arranged behind a Pulverauslassöffnung and can this Pulverauslassöffnung on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle smoothing applied raw material powder layer. Each Pulverauslassöffnung the powder chamber may comprise an outlet section of a Pulverauslassöffnung controlling closure device and / or a trained, for example in the form of a conveyor shaft conveyor to promote accommodated in the powder chamber material powder toward the Pulverauslassöffnung.

p0017A for operation without "empty runs" suitable powder coating device must therefore not necessarily having at least two separate powder chambers can be provided and can be claimed independently of this feature. However, a powder application apparatus according to the invention with separate powder chambers is also without "empty runs" operable, when the powder application device includes, for example, two powder compartments, the powder chambers are filled with the same powder, and a leveling slider between the Pulverauslassöffnungen of the two powder compartments is arranged.

p0018Alternatively, the powder application device according to the invention may also include a first and a second leveling slider cover, which are so positioned relative to the Pulverauslassöffnungen the powder chambers, that during operation of the powder application device, when the powder application device over the carrier of the plant for manufacturing work pieces by impinging powder layers with electromagnetic or particle radiation is moved, one of the leveling slider via a by at least one of Pulverauslassöffnungen on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle sweeps applied raw material powder layer to smooth the raw material powder layer. In other words, based on a moving direction of the powder application device is in operation always a leveling slider only before the Pulverauslassöffnungen positionable. The other smoothing slide however, can be positioned behind the Pulverauslassöffnungen and by Pulverauslassöffnungen on the carrier of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation applied raw material powder layer are performed on. In such an embodiment of the powder coating apparatus can be avoided "empty runs".

p0019In particular, if impurities of the processed raw material powder should be avoided, it is advantageous if each Pulverauslassöffnung a powder chamber is assigned a separate leveling slider which is so positioned relative to the Pulverauslassöffnung that it during operation of the powder application device, when the powder application device over the support of the plant is moved to the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation, via a through Pulverauslassöffnung on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle sweeps applied raw material powder layer to smooth the raw material powder layer. In other words, the leveling slider is preferably so positioned relative to the Pulverauslassöffnung that it is arranged with respect to a moving direction of the powder application device in operation behind the Pulverauslassöffnung. Again, it may with appropriate operation of the powder application device sufficient to provide only for each Pulverauslassöffnung a smoothing shifter based upon movement of the powder application device in a first direction to the moving direction of the powder application device behind the Pulverauslassöffnung, upon movement of the powder application device in a first direction opposite second direction, however, only be positioned before Pulverauslassöffnung. The movement of the powder coating apparatus in the second direction than in turn provide a "deadhead".

p0020Alternatively, can be a first and a second leveling slider associated with each Pulverauslassöffnung a powder chamber, which are so positioned relative to the Pulverauslassöffnung that during operation of the powder coating apparatus, when the powder application device via the carrier of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle is moved, one of the leveling slider via a through Pulverauslassöffnung on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle sweeps applied raw material powder layer to smooth the raw material powder layer. In this embodiment, the powder coating apparatus according to the invention a leveling slider is always relative to a moving direction of the powder coating apparatus in operation behind the Pulverauslassöffnung positioned and can be guided through the through Pulverauslassöffnung on the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation applied raw material powder layer will. This allows the avoidance of "empty runs.

p0021One or all of the leveling slider powder coating apparatus according to the invention can / may be displaced vertically between a rest position and an operating position. In its rest position, a leveling slider preferably has no contact with one produced by the powder application device, ie applied to the carrier of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle Rohstoffpulverobertläche. In its operating position the leveling slider on the other hand that is led through the heat generated by the powder application device, to the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation applied raw material powder surface to emphasize the raw material powder surface smooth and to a desired height to level. Between a rest position and an operating position sliding smoothing slider have the advantage that they, when they are not needed, do not interfere with the operation of the powder coating apparatus. The vertical displacement of the smoothing slider can be manual or automatically carried out for example, controlled by an electronic control unit.

p0022Further, the powder application device according to the invention may comprise one or more smoothing shifter / which is horizontally displaceable between a first and a second position / are. The leveling slider is then in the operation of the powder coating apparatus, when the powder application device back in opposite directions over the support of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation and forth, always positioned in such a way relative to a Pulverauslassöffnung a powder magazine that he strokes applied raw material powder layer via a through Pulverauslassöffnung on the support of the tray for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation in order to smooth the raw material powder layer. In other words, the leveling slider is moved horizontally so that it can be obtained in the operation of the powder coating apparatus positioned on a moving direction of the powder applicator always behind the Pulverauslassöffnung the powder chamber. A horizontal moveable leveling slider can be configured horizontally or both horizontally and vertically. The horizontal displacement of a slide smoothing can be manual or automatically carried out for example, controlled by an electronic control unit.

p0023If any Pulverauslassöffnung the powder application device is associated with a leveling slider, a part of the leveling slider or all leveling slider be formed horizontally displaced. Further, it is conceivable to provide the powder coating apparatus according to the invention with only one smoothing slide which is disposed horizontally between a first position in which the leveling slider with respect to a moving direction of the powder application device in operation behind all Pulverauslassöffnungen, and a second position in which relative the leveling slider is disposed on an opposite direction of motion of the powder applicator in operation behind all Pulverauslassöffnungen, is displaceable. Finally, it is conceivable to form a leveling slider of the powder application device is horizontally displaceable that the leveling slider is arranged relative in a first position to a moving direction of the powder application device in operation behind a first Pulverauslassöffnung a first powder chamber, and is related in a second position to a movement direction of the powder application device is arranged in operation behind a second Pulverauslassöffnung a second powder compartment.

p0024A horizontal or vertical sliding smoothing slider of the powder coating apparatus according to the invention may be coupled to a device for controlling the powder removal by a Pulverauslassöffnung a powder chamber, which closes the Pulverauslassöffnung the powder chamber in response to a position of the smoothing slider or releases. For example, the leveling slider and the means for controlling the powder dissipation can be coupled by a Pulverauslassöffnung a powder chamber such that the means for controlling the powder discharge closes the Pulverauslassöffnung by Pulverauslassöffnung a powder magazine when the leveling slider is in its rest position. Similarly, the leveling slider and the means for controlling the powder dissipation can be coupled by a Pulverauslassöffnung a powder chamber such that the means for controlling the powder removal by a Pulverauslassöffnung a powder chamber closes the Pulverauslassöffnung when the leveling slider with respect to a direction of movement of the powder coating apparatus in operation only is disposed in front of Pulverauslassöffnung.

p0025The control of a horizontally and / or vertically displaceable slider smoothing can be as well as the control of the means for controlling the powder discharge taken over by a Pulverauslassöffnung a powder chamber by an electronic control unit. This electronic control unit may be a solely of the powder application device associated electronic control unit. Alternatively, the required during operation of the powder application device control functions can also be acquired by a higher-level control unit of the plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation. Preferably, the electronic control unit controls the operation of the powder application device according to the invention as a function of CAD data of the to be produced by applying of powder layers with electromagnetic radiation or particle radiation, in particular laser melting or selective laser sintering workpiece.

p0026A system according to the invention for the production of workpieces by application of powder layers with electromagnetic radiation or particle comprising a support for receiving a raw material powder and a workpiece produced by a generative layer manufacturing from the raw material powder. In principle, the carrier may be a rigidly fixed carrier. Preferably the carrier is slidably but formed in the vertical direction, so that the carrier with increasing height of the layer-built workpiece can be moved vertically downwards. Further, the installation of the invention for the production of workpieces by applying of powder layers with electromagnetic radiation or particle radiation comprises a movable about the support powder applicator device for layered deposition of the raw material powder in the carrier, and an irradiation device for selectively applying a force applied to the carrier raw material powder layer with electromagnetic radiation or particle radiation, in particular laser radiation. The irradiation device preferably includes a focused laser. A beam of the irradiation device is led over the layer applied to the carrier raw material powder layer so that the layer applied to the carrier raw material powder layer is ortselektiv exposed to electromagnetic radiation or particle radiation. The heat input caused by the application of electromagnetic radiation or particle effects in the raw material powder layer, that the individual particles of the raw material powder in the raw material powder layer melt or sinter together and thereby a layered workpiece is built up. The powder coating apparatus of the inventive system for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation is a powder coating apparatus according to the invention described above.

p0027Preferred embodiments of the invention will now be explained in more detail with reference to the accompanying diagrammatic drawings, in which<dl id="dl0001"><dt>figure</dt><dd>1 is a powder coating apparatus with four powder chambers shows</dd><dt>figure 2</dt><dd>a powder applicator with two powder magazines and a vertically movable leveling slider shows</dd><dt>figure 3</dt><dd>a powder applicator with two powder magazines and two vertically sliding smoothing sliders shows and</dd><dt>figure 4</dt><dd>a powder applicator with two powder magazines and four vertically sliding smoothing sliders shows</dd><dt>figure 5</dt><dd>a powder applicator device with two chambers and a powder, both vertically and horizontally displaceable leveling slider shows</dd><dt>figure 6</dt><dd>a powder applicator with two powder magazines and two horizontally and vertically sliding smoothing sliders shows.</dd></dl>

p0028<figref idrefs="f0001">Fig. 1</figref> shows a first embodiment of a powder applicator 10, which is intended for use in a plant for the production of workpieces by application of powder layers with electromagnetic radiation or particle radiation, in particular a Laserschmelz- or laser sintering system. The powder applicator device 10 is by means of an illustrative not further drive means which can be formed for example in the form of a spindle drive or the like, as indicated by the arrows P1 and P2, linear way over a surface of a carrier 12 and reciprocally movable. In the<figref idrefs="f0001">Fig. 1</figref> Powder application device shown comprises a powder chamber 14 for receiving aufzubringendem on the surface of the carrier 12 raw material powder, which separately of one another by four rectangular formed powder chambers 16a to 16d is formed. The powder chambers 16a to 16d are releasably connected together, such that the powder application device 10 may be provided with any number of powder chambers 16a to 16d. Each powder compartment 16a to 16d can be fed via a corresponding powder supply opening 18a to 18d batchwise or continuously raw material powder.

p0029facing on its the surface of the support 12 underside are provided with Pulverauslassöffnungen 19a to 19d, the powder chambers 16a to 16d of the powder applicator 10th On the Pulverauslassöffnungen 19a to 19d can be applied to the surface of the carrier 12 raw material powder from the powder chambers 16a to 16d, while the powder application device is moved over the support surface 10. Thereby, a raw material powder layer is formed on the support surface. The raw material powder layer may then be applied to the layered structure of a workpiece by a laser device ortselektiv with electromagnetic radiation or particle radiation, in particular laser radiation. The powder chambers 16a to 16d of the powder applicator 10 can be filled with different raw material powders, the raw material powder can be plastic powder, ceramic powders and / or metal powder. By means of the powder application device 10 can thus be processed in the production of workpieces by selectively applying of powder layers with electromagnetic radiation or particle radiation, in particular laser melting or selective laser sintering various raw material powder.

p0030When in <figref idrefs="f0002">FIG. 2</figref> illustrated powder application device 10 'includes the powder room 14' two powder chambers 16a ', 16b'. The powder chambers 16a ', 16b' are separated by a partition wall 22 'from each other. The powder chambers 16a ', 16b' are connected via a common powder supply port 18 'by a designed for example in the form of a supply hose or the like suitable feeding device same or different raw material powder discontinuously or continuously fed. The powder chambers 16a ', 16b' are in turn each connected to a Pulverauslassöffnung 19a ', 19b', through which raw material powder from the powder chambers 16a ', 16b' on a surface of a support, not shown, of a plant for the production of workpieces by application of powder layers with electromagnetic or particle radiation can be applied.

p0031In the powder chambers 16a ', 16b' of the powder applicator 10 'is in each case a conveyor shaft 24a', 24b 'arranged. While the conveyor shaft 24a 'is driven by a drive means in a clockwise direction, the conveyor shaft 24b' is driven by a drive means in counter-clockwise direction. The conveyor shafts 24a ', 24b' serve ', 19b' to promote the raw material powder received in the powder chambers 16a ', 16b' toward the Pulverauslassöffnungen 19a. To improve their conveying effect the conveyor shafts' 24a ', 24b' on its surface with a plurality of recesses 26a 'are, 26b' provided. The conveyor shafts 24a ', 24b' are positioned so that they '16b,' seal in a quiescent state, ie in a non-driven state, Pulverauslassöffnungen 19a ', 19b' of the powder chambers 16a. Although in<figref idrefs="f0001">Fig. 1</figref> is not illustrated, it is understood that also in the <figref idrefs="f0001">Fig. 1</figref> Powder coater 10 shown may be provided for controlling the powder dissipation through the Pulverauslassöffnungen the powder chambers with conveyor shafts or other facilities.

p0032Further comprising the powder coating device 10 'between a Pulverauslassöffnungen 19a', 19b 'arranged leveling slider 28'. The leveling slider 28 'is used by the powder application device 10' on the support surface to smooth raw material applied powder layer and level to a desired level. When the powder applicator 10 is moved in a direction indicated by the arrow P1 direction of movement over the support surface, the smoothing slide 28 'relative to the direction of motion of the powder applicator 10 behind the Pulverauslassöffnung 19a' is disposed. The leveling slider 28 'may then via the Pulverauslassöffnung 19a' smooth coated raw material powder layer on the substrate surface and bring to a desired height. When the powder application device 10 behind the Pulverauslassöffnung 'is moved on the other hand in the direction indicated by the arrow P2 direction over the support surface of the leveling slider 28 is' 19b' is disposed. The leveling slider 28 'may then via the Pulverauslassöffnung 19b' sleek applied raw material powder layer on the substrate surface and bring to a desired height. "Empty trips" are avoided in this procedure.

p0033Consequently, the powder applicator 10 is moved in the direction of the arrow P1 on the carrier surface, when raw material powder from the powder chamber 16a 'to be applied to the support surface. In contrast, when raw material powder from the powder chamber 16b in the direction of arrow P2 'to be applied to the substrate surface, the powder application device 10' is moved over the support surface. When the powder chambers 16a ', 16b' filled with the same raw material powder, thus can be operated without "empty runs" possible.

p0034Depending on the desired layer structure of the workpiece to be produced, the operation of the powder application device 10 ', in particular when using different raw material powder in the powder chambers 16a', 16b ', however, also required include "short runs", in which the powder application device 10' is moved over the support surface, both Pulverauslassöffnungen 19a ', 19b' but are closed so that no raw material powder is applied to the support surface. To prevent the leveling slider 28 'in particular during this "empty runs" in a disturbing manner on the support surface or an existing workpiece surface sweeps, is the leveling slider 28' vertically between a rest position, in which the leveling slider 28 'no contact with one of the powder application device 10 'raw material powder surface produced or an already existing workpiece surface, and an operating position in which the leveling slider 28' is passed over the 'produced by the powder applying device 10 raw material powder surface slidable.

p0035In the <figref idrefs="f0003">Fig. 3</figref> Powder coater 10 shown 'differs according to the arrangement <figref idrefs="f0002">FIG. 2</figref> the fact that they ', 28b' includes not only one but two leveling slider 28a. When the powder application device 10 'is moved in the direction of the arrow P1 across the support surface, the leveling slider 28b' behind the Pulverauslassöffnungen 19a ', 19b' are arranged. The leveling slider 28b 'can then from the powder applicator 10' smooth to the support surface applied material powder layer and bring to a desired height. When the powder application device 10 ', however, is moved in the direction of arrow P2 on the support surface, the leveling slider 28a' behind the Pulverauslassöffnungen 19a ', 19b' are arranged. In this case, the leveling slider 28a 'of the powder coating device 10' on the support surface smooth coated material powder layer and bring to a desired height. The design of the powder applicator 10 'with two smoothing sliders 28a', 28b 'can in operation the powder applicators 10' "empty trips" are avoided because regardless of the direction of movement of the powder applicator 10 'is always a leveling slider 28a', 28b 'behind the Pulverauslassöffnungen 19a' is, 19b 'arranged.

p0036The leveling slider 28a ', 28b' are, as well as the leveling slider 28 'of the arrangement according <figref idrefs="f0002">FIG. 2</figref>Vertically between a rest position and an operating position displaced. In its rest position, have the leveling slider 28a ', 28b' no contact with a raw material powder surface 'generated by the powder coating apparatus 10 or an existing workpiece surface. In its operational position the leveling slider 28a ', 28b' on the other hand via the 'generated by the powder applicator 10 raw powder surface to smooth them and bring them to a desired height. The leveling slider 28a ', 28b' are independently controllable in its rest position and its operating position. Preferably located in a mode of powder applicator 10 'whichever is leveling slider 28a', 28b 'in its operating position, the relation to the direction of movement of the powder applicator 10' ', 19b' arranged behind the Pulverauslassöffnungen 19a. The relation to the movement direction of the powder coating device 10 'before the Pulverauslassöffnungen 19a', 19b 'positioned leveling slider 28a', 28b 'is located to the operation of the powder applicator 10' is usually in its rest position. Moreover, in accordance with the structure and operation of the powder application device 10 'according to<figref idrefs="f0003">Fig. 3</figref> the structure and operation of the arrangement according to <figref idrefs="f0002">FIG. 2</figref>,

p0037<figref idrefs="f0004">Fig. 4</figref> shows a powder coating device 10 ', which according to the arrangement <figref idrefs="f0003">Fig. 3</figref> differs in that it 'to 28d' comprises instead of two four leveling slider 28a. The leveling slider 28a ', 28b' of Pulverauslassöffnung are 'associated and serve on a Pulverauslassöffnung 19a' 19a to smooth raw material powder layer formed on a substrate surface and to bring to a desired height. The leveling slider 28c ', 28d' hand of Pulverauslassöffnung are 'associated with and serve to smooth a raw material powder layer and to bring to a desired height on the Pulverauslassöffnung 19b' 19b is applied to the carrier surface. The leveling slider 28a 'to 28d' are independently vertically between a rest position in which they have no contact with a 'generated by the powder applicator 10 raw powder surface or an existing workpiece surface, and an operating position in which it on the powder applicator 10 raw material powder surface 'generated are guided slidably.

p0038If the raw material powder feed from the powder applicator 10 is carried out 'on the support surface on the Pulverauslassöffnung 19a', are located the Pulverauslassöffnung 19b 'associated leveling slider 28c', 28d 'in its rest position. One of Pulverauslassöffnung 19a 'associated leveling slider 28a', 28b 'is against it in its operating position. This is the case of a movement of the powder application device 10 'in the direction of arrow P1 of the leveling slider 28b' and upon movement of the powder application device 10 'in the direction of the arrow P2 the leveling slider 28a'. When the powder feed from the powder applicator 10 is carried out 'on the support surface on the other hand Pulverauslassöffnung 19b', are located the Pulverauslassöffnung 19a 'associated leveling slider 28a', 28b 'in its rest position. One of Pulverauslassöffnung 19b 'associated leveling slider 28c', 28d 'is against it in its operating position. Upon movement of the powder application device 10 'in the direction of arrow P1 that is the leveling slider 28d' and upon movement of the powder application device 10 'in the direction of arrow P2 the leveling slider 28c'.

p0039By using different smoothing slider 28a 'to 28d' to smooth over various Pulverauslassöffnungen 19a ', 19b' of the powder applicator 10 to 28d 'adhering powder particles' given raw material powder layers contamination of the raw material powder layers to the smoothing sliders 28a' reliably prevented. Furthermore, the powder coating apparatus 10 are through the use of four smoothing sliders 28a 'to 28d' in operation ' "empty runs" avoided because regardless of the direction of movement of the powder applicator 10' each Pulverauslassöffnung 19a ', 19b' always behind the Pulverauslassöffnung 19a ', 19b' arranged leveling slider is assigned to 28a 'to 28d'. Moreover, in accordance with the structure and operation of the powder application device 10 'according to<figref idrefs="f0004">Fig. 4</figref> the structure and operation of the arrangement according <figref idrefs="f0003">Fig. 3</figref>,

p0040In the <figref idrefs="f0005">Fig. 5</figref> illustrated powder application device 10 'differs from the arrangement in accordance with <figref idrefs="f0003">Fig. 3</figref> in that they are not two, but merely a leveling slider 28 "includes. The leveling slider 28" is not only vertically between a rest position and an operating position, but also horizontally between a first and in <figref idrefs="f0005">Fig. 5</figref> indicated by dashed lines second position displaced. When the powder applicator 10 'is moved in the direction of arrow P1 on a support surface, the leveling slider 28' in its first position is behind the Pulverauslassöffnungen 19a ', 19b' and can of the powder applicator 10 'smooth raw material powder layer produced and to a desired height bring. With a movement of the powder coating apparatus 10 'in the direction of arrow P2, the leveling slider 28 "hand in his in<figref idrefs="f0005">Fig. 5</figref> shown dashed second position be placed where it is, 19b 'arranged in turn based on the moving direction of the powder applicator 10' behind the Pulverauslassöffnungen 19a '. The use of a horizontally displaceable smoothing slide 28 'thus allows the operation of the powder application device 10', the avoidance of "empty runs", without the need, as in the arrangement according to<figref idrefs="f0003">Fig. 3</figref>, A second slide is required. Moreover, the structure and operation of the powder coating apparatus 10 correspond according to<figref idrefs="f0005">Fig. 5</figref> the structure and operation of the in <figref idrefs="f0003">Fig. 3</figref> arrangement shown.

p0041Finally shows <figref idrefs="f0006">Fig. 6</figref> a powder application device 10 ', which in two vertically between a rest position and an operating position and horizontally between a first and a <figref idrefs="f0006">Fig. 6</figref> dashed second position shown are displaced. The leveling slider 28a "is' allocated during the leveling slider 28b of Pulverauslassöffnung 19b of Pulverauslassöffnung 19a '' is assigned.

p0042When is output during operation of the powder applicator 10 'above the Pulverauslassöffnung 19a' powder, is the leveling slider 28b 'in its rest position. With a movement of the powder coating apparatus 10' in the direction of arrow P1 is the leveling slider 28a "hand in its first position and upon movement of the powder application device 10 'in the direction of arrow P2 in its in <figref idrefs="f0006">Fig. 6</figref> second position shown in dashed lines. If on the other hand on the Pulverauslassöffnung 19b 'is applied to a substrate surface material powder, is the leveling slider 28a "in its rest position. With a movement of the powder applicator 10' is in the direction of arrow P1 the leveling slider 28b" in its first position and in a movement the powder coater 10 "in the direction of arrow P2 in its in<figref idrefs="f0006">Fig. 6</figref> second position shown in dashed lines.

p0043Similarly to the arrangement <figref idrefs="f0005">Fig. 5</figref> be through the use of horizontal sliding smoothing slider 28a ", 28b" in the in <figref idrefs="f0006">Fig. 6</figref> illustrated powder application device 10 ' "empty runs" avoided during operation. Moreover, can be reliably avoided by the assignment of separate leveling slider 28a ", 28b" to the Pulverauslassöffnungen 19a ', 19b' impurities in the raw material powder layer 'produced by the powder applying device 10 on a support surface through the smoothing shifters 28a ", 28b" adhering powder particles. Moreover, in accordance with the structure and operation of the powder application device 10 'according to<figref idrefs="f0006">Fig. 6</figref> the structure and operation of the in <figref idrefs="f0005">Fig. 5</figref> illustrated arrangement.