DE102016111660A1 - Powder drying in generative production - Google Patents

Abstract

A production device (1) for the generative production of a three-dimensional component (3) from a powder (5) has a production space (11) which provides a working surface (21) and comprises a building platform area (23A) and a powder reservoir area (23B). Furthermore, the manufacturing device (1) has a beam source (51) for generating a jet for the irradiation of powder (5) in the building platform region (23A) for the layered production of the component (3), a powder reservoir (25) for providing the powder (5). through a supply opening (21B) in the work surface (21) into the powder reservoir area (23B) and a pushing device (19) for transferring the powder from the powder reservoir area (23B) into the building platform area (23A). Furthermore, the manufacturing apparatus (1) has a gas system (41), for example a gas circulation system, for providing a drying gas stream (40) via the supply opening (21B) in the working surface (21) for absorbing moisture from an uppermost layer of powder (21). 5A) flows on.

Description

The present invention relates to an apparatus for laser-based additive manufacturing, and more particularly to the provision of dry powder for additive manufacturing. Furthermore, the invention relates to a method for drying powder for the additive production of a component in a generative manufacturing device.

The laser-based additive production of, in particular metallic or ceramic, workpieces is based on solidification of a starting material in powder form by the irradiation with laser light. This concept - also known as Selective Laser Melting, Powder Bed Fusion or Laser Metal Fusion (LMF) - is used, among other things, in (metallic) 3D printing machines. An exemplary machine (herein abbreviated to LMF machine) for manufacturing three-dimensional products is disclosed in US Pat EP 2 732 890 A1 disclosed. The advantages of generative manufacturing are generally a simple production of complex and customizable parts. In this case, in particular defined structures in the interior and / or power flow optimized structures can be realized.

Among other things, the state of the powder is important for a reproducible interaction of the laser light with the powder, since, for example, a varying water content in the powder can lead to different melting processes and thus to differently solidified material structures. The moisture content of the powder depends, among other things, on storage and weather conditions when the powder is loaded into the LMF machine. An increased moisture content, for example, can lead to increased porosity of the material (see, eg "Formation and reduction of hydrogen porosity during selective laser melting of AlSi10Mg", Weingarten et al., Journal of Materials Processing Technology 221 (2015) 112-12 ). Furthermore, the flowability of the powder can be reduced by too high a moisture content.

For drying the powder, various approaches are known. Thus, it is attempted to dry the powder before use in the machine, for example with the aid of dry bags in the storage containers of the powder. However, this can have the disadvantage that the effect of the desiccant degrades during long storage. Furthermore, the desiccant can accidentally get into the space. For example, disclosed EP 2 992 986 A1 the use of a drying agent in the gas or powder cycle of a device for the production of 3D components.

Further disclosed US 9,156,056 B2 a drying unit for drying powder charged in a storage tank by heating the storage tank. This procedure may have the disadvantage that the drying takes longer with increasing size of the reservoir. Thus, the ratio of the surface of the powder in the reservoir, which is directly exposed to the surrounding atmosphere and thus allows removal of moisture from the powder in the reservoir, to the total volume of the powder in the reservoir decreases.

Further disclosed EP 3 023 228 A1 a machine for the generative production of three-dimensional products on a platform, which provides a gas flow over the platform to remove, for example, smoke from the interaction zone. Other gas circulation configurations are eg DE 10 2010 052 206 A1 . DE 10 2006 014 835 A1 and WO 2010/007394 A1 known.

One aspect of this disclosure is based on the object of bringing the moisture content of the powder for the building application to a low, and if possible, during production substantially constant, level.

At least one of these objects is achieved by a manufacturing apparatus for the additive production of a three-dimensional component from a powder according to claim 1 and by a method for drying powder for the additive manufacturing according to claim 11. Further developments are specified in the subclaims.

In one aspect, a manufacturing apparatus for generatively manufacturing a three-dimensional component from a powder includes a workspace providing a work space including a build platform area and a powder reservoir area, a beam source for generating a beam for powder irradiation in the build platform area for making the component, a powder reservoir for supplying the powder through a supply opening in the work surface into the powder reservoir area, a pushing device for transferring the powder from the powder reservoir area to the building platform area, and a gas system for providing a drying gas flow over the supply opening in the work area to receive moisture from an uppermost layer of the powder flows.

In some embodiments, the manufacturing apparatus further comprises a build cylinder having a lowerable die providing a platform for forming a powder bed and a component powder area defined by the platform connected to the build platform area through an irradiation opening in the work surface Gas system the Dry gas stream forms substantially transversely to the alignment direction of the openings in the work surface.

Furthermore, the gas system may comprise an outlet opening structure, in particular arranged on or in a front wall or a door of the production apparatus, and a suction opening structure, in particular arranged on or in a rear wall of the production apparatus, wherein the outlet opening structure and the suction opening structure are arranged on opposite sides of the supply opening. The outlet opening structure and / or the suction opening structure may be designed in such a way that a flow pattern of the drying gas stream in the powder reservoir region which is directed in the direction of the supply opening, in particular laminar, is formed. Furthermore, the gas system can be designed as a gas circulation system, which comprises a filter unit with a drying medium for removing moisture from the gas, and wherein the drying medium is arranged in particular in a replaceable, and for example separable via valves component in the gas cycle. In general, the gas system may further comprise a protective gas tank and / or an inert gas connection, a pump system, valves and / or lines for connecting the individual components of the gas circulation system, in particular comprising argon or nitrogen. The gas system can be subdivided into a main housing section, which is arranged below and behind the production space, for example, and a (door) section, for example integrated in a door.

In some embodiments, the gas system is configured to provide a particulate discharge gas stream, particularly parallel to the drying gas stream, extending above the irradiation port in the working surface for discharging particles from an interaction zone in the building platform region.

In some embodiments, the manufacturing apparatus further comprises a control unit for adjusting the drying gas flow and in particular the Partikelabführgasstroms and / or adjusting the position of the pusher during the irradiation process between the supply port and the irradiation port for separating the drying gas flow from the Bauplattformbereich and in particular the Partikelabführgasstrom a heat radiator for generating a directed to the supply opening, and in particular also to the irradiation heat radiation, wherein the heat radiator is further arranged in particular in the production space in the region above the supply opening. The heating from above has the advantage that substances adsorbed to the powder, such as water (moisture), in a top powder layer after heating, desorb faster and diffuse through the powder, so that the powder of the top powder layer is dried faster by the drying gas stream ,

Under special conditions, the underlying powder layers can (strongly) heat up in spite of the usually poor heat conduction properties of the powder in such a way that moisture increasingly diffuses out of them into the upper powder layer. In order to prevent or minimize this undesirable effect (in particular during a parallel production process), it is important to ensure that not too much heat is introduced into the upper powder layer. As a result, the advantageous effect of moisture removal (only from the upper layer), which saturates with increasing temperature, can be retained. Optimal heat input can be determined depending on the material, for example.

In a further aspect, a method of drying powder for additive manufacturing includes the steps of providing a quantity of fresh powder above a supply port in a work surface and providing a drying gas stream that flows through the supply port in the work surface to receive moisture from an uppermost one Position of the powder flows.

The provision of the amount of fresh powder may be accomplished by gradually increasing a powder supply amount across the working surface through the supply port, providing the drying gas stream simultaneously with a powder irradiation process at an irradiation port, and / or the drying gas stream may be substantially transverse to the alignment direction of the openings in the working surface stream.

Further, the method may include a drying assisting step of heating the above-prepared supply amount of fresh powder from above, the heating particularly by irradiating heat radiation to the supply opening, and in particular also to the irradiation opening in the work surface for heating the uppermost Location of the powder can be done.

An advantage of the concepts described herein is that drying can act almost immediately on the powder used to build up the subsequent layers. It is not absolutely necessary to dry the powder in the LMF machine or even for hours before, thus delaying the start of the production process.

In general, the concepts described herein may allow stabilization of the manufacturing process against variations in the humidity of the powder used. Furthermore, external drying times of the powder can be reduced or even completely eliminated. Thus, the concepts described herein may allow an acceleration of the start of production by the rapid drying of the stepwise required amounts of powder using an argon stream, for example, since the slow drying of the entire powder can be dispensed with.

Moreover, the structures described herein may allow a simple and rapid change of the drying medium in the gas cycle through the use of desiccant packages. For example, a change of desiccant packages within a minute or less.

The concepts described herein may further have the advantage that the drying process is parallel to the main time, i. at the same time as the construction phase, expires.

Herein, concepts are disclosed that allow to at least partially improve aspects of the prior art. In particular, further features and their expediencies emerge from the following description of embodiments with reference to the figures. From the figures show:

1 a schematic spatial representation of an exemplary generative manufacturing device,

2 a schematic sectional view of the generative manufacturing device 1 parallel to the XY plane through the production room,

3 a schematic sectional view of the generative manufacturing device 1 parallel to the XZ plane through the production room as in 2 indicated,

4 a schematic sectional view of the generative manufacturing device 1 parallel to the YZ plane through the production room as in 2 indicated and

5 a sketch to illustrate an exemplary gas cycle of a generative manufacturing device.

Aspects described herein are based, in part, on the recognition that targeted drying of a topmost powder layer can be effected by a (e.g., dried argon) blanket gas stream. A complete and lengthy drying of the entire amount of powder (based on a diffusion of water vapor through the porosity in the powder bed) before, during or after the filling of the reservoir can be omitted when using such a surface drying stream.

The following is with reference to the 1 to 4 an embodiment of an LMF machine, which is designed to provide such, integrated in the manufacturing process, powder drying operation. 5 shows an exemplary gas cycle for use in such LMF machines.

In 1 is an exemplary generative manufacturing device 1 for producing a 3D component 3 from a powder 5 shown. For the manufacturing process is on the above-mentioned EP 2 732 890 A2 directed. The manufacturing device 1 includes a main body 11 that has a production room 13 provides. A front wall 15 limits the production space 13 on the front side. The main body 11 also has a back wall 18 , Side walls and a ceiling on which together the production room 13 define. The front wall 15 has a front frame 15A with an opening 17 on, through which an access to the production room 13 the manufacturing device 1 is possible. The opening 17 can during the manufacturing process by a eg on the front wall 15 attached door 31 (Handle 31A , Closure 31B ) are closed (see 2 ). With the door open 31 there is access to the production area 13 the manufacturing device 1 (please refer 1 ) and an operator can, for example, the necessary preparatory steps such as cleaning the production room 13 and refilling the powder reservoir and the finished component 3 remove.

1 further shows a slider 19 (also called wiper herein) for distributing the powder 5 during the manufacturing process. The manufacturing process takes place on a work surface 21 instead of the floor of the production room 13 forms. The work surface 21 has a build platform area 23A , a powder reservoir area 23B and (optionally) a powder collection area 23C on. The building platform area 23A can be central to the opening 17 be provided. It contains the irradiation process for the production of the 3D component 3 instead of. The powder reservoir area 23B serves to provide fresh powder 5A , for the layer-wise production of the 3D-component 3 in the building platform area 23A with the slider 19 is transmitted.

As in 2 shown is the building platform area 23A in the X direction (ie with respect to the opening 17 in the transverse direction) between the powder reservoir region 23B and the powder collection area 23C arranged. The powder reservoir area 23B has an example cylindrical powder reservoir 25 on whose upper end in a (powder) Deployment opening 21B the work surface 21 empties. Using a stamp 25A may gradually, for example, metallic or ceramic powder 5 from the powder reservoir 25 over the work surface 21 be raised (along arrow 26 ). If a new layer is needed for irradiation, you can use the slider 19 that over the work surface 21 protruding fresh powder 5A laterally in the X direction in the building platform area 23A be moved. Accordingly, the slider extends 19 in 2 in the Y direction, which is orthogonal to the transverse direction (X direction) in the work surface 21 runs.

The building platform area 23A has an example cylindrical cylinder construction 27 with a lowerable, a platform for forming a powder bed providing stamp 27A on. As a result of the lowering, a component-powder region delimited by the platform is formed, which passes through the irradiation opening 21A in the workspace 21 with the building platform area 23A connected is. Became a layer of the component 3 by fusing powder 5 formed, the stamp becomes 27A lowered so that one through an irradiation opening 21A in the workspace 21 limited depression forms into which the fresh powder 5A with the slider 19 can be moved, so that forms a new upper powder layer in the powder bed to be irradiated. Not needed to build up the new layer needed powder 5B can with the slider 19 through an opening 21C the work surface 21 in the powder collection area 23C for example, be moved to a collection container for recycling.

The main body 11 further comprises at least parts of a gas circulation system 41 on, such as a protective gas tank and / or a protective gas connection and a pump system (not shown) and a filter unit 71 , The gas circulation system 41 allows the production room 13 To flood with eg inert gas such as argon or nitrogen during the manufacturing process. Further details of the gas circulation system 41 are hereinafter in particular in connection with 5 explained.

An irradiation system 51 can on the main body 11 eg over the building platform area 23A be attached. The radiation system 51 is for generating radiation, eg laser light, which is the powder 5 to material layers of a component 11 can merge, trained. It is based for example on a fiber or disk laser system. Alternatively, laser light from such a source may become the main body 11 be guided. The main body 11 has a scanner system that puts the radiation in one onto the component 3 coordinated path in the construction platform area 23A can lead to local melting of the uppermost powder layer of the powder bed.

As mentioned above, the parameters of the powder influence the interaction of the radiation / the laser light with the powder and thus the fusion of the powder grains. In particular, the moisture content of the powder affects the manufacturing process.

To the moisture content of the powder 5 to reduce immediately before the interaction with the jet is the gas circulation system 41 designed such that a surface drying stream 40 the protective gas over / on the opening 21B the work surface 21 and thus on / on the uppermost powder layer of the powder reservoir 25 is directed. The protective gas is preferably "dried", for example it has a moisture content of less than about 0.0005 g / l. Examples of dry shielding gases are argon and nitrogen. Drying of the shielding gas may be accomplished by passing the shielding gas through or over a drying medium / desiccant (eg LECO anhydrone) in the gas circulation system 41 respectively.

In the embodiment shown, the drying gas flow is formed 40 essentially transverse to the alignment direction (here the X-direction) of the openings 21A . 21B out, ie it flows according to the Y-direction over the opening 21A in the workspace 21 ,

The drying and the subsequent transfer of the dried gas over the uppermost powder layer in the powder reservoir 25 can be designed to just that small amount of powder (small compared to the total amount of powder in the powder reservoir 25 ) to dry immediately following for building the next layer of the component 3 is used with the laser beam. Because essentially only the upper layer of powder 5A is used in the storage container for the next layer, the amount of powder to be dried is low, so that the powder 5A can be sufficiently dried by the protective gas flowing along. In general, the drying before, during and / or after lifting the stamp 25A , in particular permanently.

An exemplary realization of the desired flow profile in the production room 13 can through that in the 1 to 4 clarified gas circulation system 41 respectively. In this case, the flow pattern is implemented, for example in combination with a special flow pattern for Rußabfuhr, in which a (Rußabfuhr-) gas flow 42 from the door 31 out to the back wall 18 (or in the opposite direction) over the building platform area 23A flows. Here, carbon black is representative of very small particles that can form when the laser light interacts with the powder. In order to prevent any influence on the production process (deposition on optics or the component itself), These small particles can be blown out of the interaction area by a corresponding flow and then sucked off.

The gas circulation system 41 includes a main body section 41A for example, below and behind the production room 13 is arranged, and one in the door 31 integrated door section 41B , The main body section 41A includes, for example, the protective gas tank and / or the protective gas connection to an external source of inert gas, the pump system and the filter unit 71 of the gas circulation system 41 ,

The filter unit 71 is with a suction port structure 55 in the back wall 18 over a line 46A fluidly connected. The suction port structure 55 is in the range of the powder reservoir area 23B near the work surface 21 arranged. In 2 is an extension of the suction port structure 55 in the building platform area 23A indicated by dashed lines.

Further, the filter unit 71 with an outlet opening structure 45A in the door 31 fluidly connected. This includes the main body section 41A of the gas circulation system 41 a line 46B to the front wall 15 , which in a (housing) connection opening 43A in one of the door 31 covered area opens. The connection opening 43A stands with the door closed 31 via a (door) connection opening 43B in fluid communication with the door section 41B of the gas circulation system 41 ,

Accordingly, the door section comprises 41B the outlet port structure 45A for the drying stream, possibly a further outlet opening structure 45B for the soot exhaust stream, the connection port 45A and one or more interconnecting lines 47 from the connection opening 45A to the outlet port structures 45A . 45B , In some embodiments, for example, switchable valves or a plurality of connection openings may be provided to prevent the outflow of the protective gas from the outlet opening structures 45A . 45B to be able to control. Furthermore, the outlet opening structure 45A and / or the Absaugöffnungsstruktur 55 be shaped so that as laminar as possible (towards supply opening 21B ) directed flow as close as possible over the powder reservoir area 23B forms (see surface drying current 40A in 4 ).

General is the gas cycle system 41 formed on one side of the powder reservoir area 23B (dry) inert gas in the direction of the opening 21B the work surface 21 let flow out and dissipate the protective gas on an opposite side, wherein the shielding gas some moisture from the powder 5A has taken up (if the powder 5A Is "wet"). In this way, a (possibly previously dried) gas stream can be passed through the powder reservoir in the reservoir, which dries a thin layer of powder on the surface of the powder reservoir. Due to the positioning near the powder reservoir area 23B and possibly due to the special shaping of the surface drying stream 40 be formed uniformly, so that a uniformly drying over the entire surface of the current over the powder 5A to be led. This can allow uniform drying of the topmost layer of powder during the manufacturing process. That is, at the same time for drying can in the construction cylinder 27 a - previously dried and distributed - powder layer are exposed to the 3D component 3 to sinter in layers, ie to melt the powder layer by layer.

For the exposure of the next layer, the powder dried during the preceding layer formation is passed through the slider 19 on the previously irradiated and lowered powder surface in the construction cylinder 27 distributed. While from it the next layer of the component 3 is generated, the same amount of powder can be dried again at the same time.

In 2 is also a heat radiator 59 shown schematically on the opening 21B in the workspace 21 directed and can support the drying process. Radiant heaters 59 is designed for heating the powder from above. In addition, he can also for the preheating of the powder in the region of the opening 23A be used.

Furthermore, the slider can 19 be formed or positioned during drying so that the drying of the powder surface is as uniform as possible. For example, during the irradiation of the slider 19 in a waiting position between the powder reservoir area 23B and the build platform area 23A be positioned (see 2 ), so that the different streams for drying and Rußabfuhr not influence. Furthermore, the respective currents can be activated, reduced or completely suppressed as a function of the current method step.

As previously exemplified, the implementation of the concepts disclosed herein into the inert gas purge of the overall system, particularly the inert gas purge of at least a majority of the manufacturing space, may be integrated throughout the manufacturing process. In summary, a dry gas stream is deliberately passed over the powder to be dried. A correspondingly "moist" gas stream is discharged from the chamber. As explained above, the inert gas can circulate in a gas circulation in which the gas stream is dried with a desiccant and possibly. is additionally cleaned with a filter for the separation of micro particles / suspended matter such as soot. Alternatively, the gas stream may be part of a higher-level gas drying and purification process, ie, dry gas is supplied and the humidified gas is fed to a central treatment.

In 5 a gas cycle is shown schematically. One recognizes a drying protective gas flow 81A and (dashed) an optional carbon black purge gas stream 81B through the production space shown schematically 13 , About gas lines 52 becomes the moist (and possibly soot-containing) protective gas of the filter unit 71 fed.

The filter unit 71 has a fine filter 73 for removing particles from the gas stream. Subsequent drying of the gas stream takes place by transfer via a drying medium in a preferably easily exchangeable component, for example a pipe 75 , The pipe 75 For example, by valves 77 be separated at both ends of the gas cycle, so that the drying medium used can be easily and quickly replaced.

In general, make sure that the drying medium is the powder 5 in the production room 13 not contaminated. This can be avoided, for example, with a further filter (not shown) or with correspondingly fine-pored packaging of the drying medium.

The purified and dried gas stream is then passed through lines 52 and possibly valves 79 in the production room 13 recycled. If the gas flow is supplied to different areas, the valves can 79 for adjusting the flow paths and the flow rates with a control unit (not shown) are driven. The gas streams for drying and Rußabfuhr can thus be integrated or formed separately from each other.

Further, as previously mentioned, for spatially separating the gas stream for drying from the gas stream for soot removal, the gate valve 19 during the irradiation to take a waiting position between the reservoir and the building cylinder, for example, also be controlled with the control unit.

The tube with the drying medium can be placed in front of the ultrafine filter 73 be installed for soot deposition, as well as after this filter. In the former case, no additional retention filter is necessary for the drying medium.

Alternatively to the use of a drying medium, the moisture may be due to a cold trap in the filter unit 71 be removed from the gas stream.

LMF machines in which the concepts described herein can be used include, for example, the "mysint 100", "TruPrint 1000" and "TruPrint 3000" systems.

It is explicitly pointed out that all features disclosed in the description and / or the claims are considered separate and independent of each other for the purpose of original disclosure as well as for the purpose of limiting the claimed invention independently of the feature combinations in the embodiments and / or the claims should. It is explicitly stated that all range indications or indications of groups of units disclose every possible intermediate value or subgroup of units for the purpose of the original disclosure as well as for the purpose of restricting the claimed invention, in particular also as the limit of a range indication.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2732890 A1 [0002]
• EP 2992986 A1 [0004]
• US 9156056 B2 [0005]
• EP 3023228 A1 [0006]
• DE 102010052206 A1 [0006]
• DE 102006014835 A1 [0006]
• WO 2010/007394 A1 [0006]
• EP 2732890 A2 [0030]

Cited non-patent literature

• "Formation and reduction of hydrogen porosity during selective laser melting of AlSi10Mg", Weingarten et al., Journal of Materials Processing Technology 221 (2015) 112-12 [0003]

Claims (13)

Manufacturing device ( 1 ) for the generative production of a three-dimensional component ( 3 ) from a powder ( 5 ) with a working surface ( 21 ) providing production space ( 11 ) containing a building platform area ( 23A ) and a powder reservoir area ( 23B ), a beam source ( 51 ) for generating a jet for the irradiation of powder ( 5 ) in the building platform area ( 23A ) for layering the component ( 3 ), a powder reservoir ( 25 ) for providing the powder ( 5 ) through a delivery opening ( 21B ) in the workspace ( 21 ) into the powder reservoir area ( 23B ), a pushing device ( 19 ) for transferring the powder from the powder reservoir area ( 23B ) in the building platform area ( 23A ) and a gas system ( 41 ) for providing a drying gas stream ( 40 ), via the deployment opening ( 21B ) in the workspace ( 21 ) for absorbing moisture from an uppermost layer of the powder ( 5A ) flows. Manufacturing device ( 1 ) according to claim 1, further comprising a building cylinder ( 27 ), comprising a lowerable, a platform for forming a powder bed providing stamp ( 27A ) and a component-powder region delimited by the platform, which is penetrated through an irradiation opening ( 21A ) in the workspace ( 21 ) with the building platform area ( 23A ), wherein the gas system, the drying gas flow ( 40 ) substantially transversely to the alignment direction of the openings ( 21A . 21B ) in the workspace ( 21 ) trains. Manufacturing device ( 1 ) according to claim 1 or 2, wherein the gas system ( 41 ) comprises: an outlet port structure ( 45A ), in particular arranged on or in a front wall ( 15 ) or a door ( 31 ) of the manufacturing device ( 1 ), and a suction opening structure ( 55 ), in particular arranged on or in a rear wall ( 18 ) of the manufacturing device ( 1 ), wherein the outlet opening structure ( 45A ) and the suction opening structure ( 55 ) on opposite sides of the delivery opening ( 21B ) are arranged. Manufacturing device ( 1 ) according to claim 3, wherein the outlet opening structure ( 45A ) and / or the suction opening structure ( 55 ) are formed such that a towards deployment opening ( 21B ) directed, in particular laminar, flow pattern of the drying gas stream ( 42 ) in the powder reservoir area ( 23B ) trains. Manufacturing device ( 1 ) according to one of the preceding claims, wherein the gas system ( 41 ) is further configured as a gas circulation system, which has a filter unit ( 71 ) with a drying medium for removing moisture from the gas, and wherein the drying medium in particular in a replaceable, and for example via valves ( 77 ) detachable component ( 75 ) is arranged in the gas circuit. Manufacturing device ( 1 ) according to one of the preceding claims, wherein the gas system ( 41 ) further comprises a protective gas tank and / or a shielding gas connection, a pump system, valves and / or lines for connecting the individual components of the particular argon or nitrogen leading gas circulation system. Manufacturing device ( 1 ) according to one of the preceding claims, wherein the gas system ( 41 ) in a main housing section ( 41A ), for example below and behind the production room ( 13 ), and one, for example in a door ( 31 ) integrated (door) section ( 41B ) is subdivided. Manufacturing device ( 1 ) according to one of the preceding claims, wherein the gas system ( 41 ) further for providing, in particular parallel to the drying gas flow ( 40 ), Partikelabführgasstroms ( 42 ), which extends above the irradiation opening ( 21A ) in the workspace ( 21 ) for removing particles from an interaction zone in the building platform area ( 23A ). Manufacturing device ( 1 ) according to any one of the preceding claims, further comprising a control unit for adjusting the drying gas flow ( 40 ) and in particular the Partikelabführgasstroms ( 42 ) and / or for adjusting the position of the sliding device ( 19 ) during the irradiation process between the delivery opening ( 21B ) and the irradiation opening ( 21A ) for the spatial separation of the drying gas stream ( 40 ) from the building platform area ( 23A ) and in particular the Partikelabführgasstrom ( 42 ). Manufacturing device ( 1 ) according to any one of the preceding claims, further comprising a heat radiator ( 59 ) for generating one on the supply opening ( 21B ), and in particular on the irradiation opening ( 21A ), directed heat radiation, the heat radiator ( 59 ) also in particular in the production room ( 11 ) in the area above the deployment opening ( 21B ) is arranged. Process for drying powder ( 5 ) for additive manufacturing, comprising the steps of providing a quantity of fresh powder above a delivery opening ( 21B ) in a workspace ( 21 ) and providing a drying gas stream ( 40 ), via the deployment opening ( 21B ) in the workspace ( 21 ) for absorbing moisture from an uppermost layer of the powder ( 5A ) flows. The method of claim 11, wherein providing the amount of fresh powder by gradually increasing a powder supply amount across the work surface (10). 1 ) through the delivery opening ( 21B ), providing the drying gas stream ( 40 ) at the same time as a powder irradiation process at an irradiation opening ( 21A ) and / or the drying gas stream ( 40 ) substantially transversely to the alignment direction of the openings ( 21A . 21B ) in the workspace ( 21 ) flows. Method according to one of claims 11 or 12, further comprising the step of supporting the drying operation: heating above the supply opening ( 21B ) provided amount of fresh powder ( 23B ) from above, in particular by irradiation of heat radiation on the supply opening ( 21B ), and in particular on the irradiation opening ( 21A ), in the workspace ( 21 ) for heating the uppermost layer of the powder ( 5A ).

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