DE102017207764A1 - Method and device for producing a three-dimensional composite structure according to a printing method - Google Patents

Abstract

Suggested is u.a. a method for producing a three-dimensional composite structure (1) according to a printing method, comprising the following steps: a) applying a first layer (10) of pulverulent and / or granular material (6) to a vertically adjustable build-up platform (4), b) selective impregnation the first layer (10) with a binder (11) corresponding to the shape of the composite structure (1) to be produced, and c) layered application of at least one further layer (10) of pulverulent and / or granular material (6), wherein each further layer (10) 10) is impregnated selectively with said binder (11) in accordance with the shape of the composite structure (1) to be produced, and the build platform (4) is lowered by the respective layer thickness, either (d) each selectively impregnated with binder (11) layer (10) of powdered and / or granular material (6) or d2) a layer (10) of pulverulent and / or of two or more selectively impregnated with binder (11) the granular material (6) of existing layer structure (20) is selectively solidified due to heat input, and where e) the heat input by irradiation with high-energy microwaves (19) results and uses the building platform (4) as a microwave antenna (13) at least one microwave device (12) becomes.

Description

The invention relates to a method for producing a three-dimensional composite structure according to a printing method according to the combination of features of claim 1 of the invention. According to the combination of features of claim 6 of the invention further relates to an apparatus for performing said manufacturing method.

Methods and devices for producing a three-dimensional composite structure according to a printing method by means of so-called 3D printers have been known for quite some time in various embodiments. That's how it describes CN 203282709 U a 3D printer of the so-called type melt deposition, in which computer-supported by a so-called FDM (FDM = Fused Deposition Modeling) layer by layer meltable plastic is applied to a surface and melted by a heater. The heating device may be formed by an infrared, laser and / or microwave-based heating device. The US 2015/0054204 A1 describes a system for producing a three-dimensional object by means of a 3D printer according to said FDM (Fused Deposition Modeling) method, which has a plurality of print heads for depositing, for example, two or more different materials, such as metal and / or ceramic, in powder form. The 3D printer further includes a high power microwave source having a radiation shaping unit disposed above a workpiece to be heated. Once the said material is deposited on the workpiece, the radiation shaping unit is controlled by means of a control unit such that the deposited material is heated and fused to the workpiece. The US 2016/0096327 A1 describes a 3D printing according to said FDM (FDM = Fused Deposition Modeling) method in which heat-settable materials such as polymers and high-temperature thermoplastics are deposited layer by layer on a height-adjustable structural panel of an insulated building chamber. For this purpose, at least a first heating device, for example in the form of heating coils near the print head and near an upper wall of the building chamber is arranged, which heats the air within the chamber by heat radiation and convection. In order to avoid distortion of the three-dimensional body to be formed by undefined cooling thereof, a second heating device is provided which heats the building board. The US 2016/0297142 A1 describes a 3D printing process in which one or more inks such as a thermopolymer ink, a nano-filler ink, and a thermopolymer / nano-filler ink are prepared, an object printed by depositing alternating layers of said inks, and the layers be exposed to microwave radiation, whereby the thermopolymer melts. The construction of the three-dimensional object takes place on a height-adjustable construction platform. The DE 102 35 434 A1 describes a 3D printing according to said FDM (Fused Deposition Modeling) method, in which a three-dimensional object is produced in layers by means of a powdered building material and an adhesive, by connecting layers of the building material to places corresponding to the cross section of the object. In addition, this document describes a layer structure on a height-adjustable construction platform, wherein the material application is selectively solidified by means of a laser by the powder is sintered. Alternatively or in combination with the method described above, for example, a device for solidifying the powder by means of an adhesive may be provided.

The object of the invention is to provide a process, which is alternative with respect to the prior art, for producing a three-dimensional composite structure according to a printing process, which is labor-intensive and permits an increased production turnover. It is another object of the invention to provide a suitable device for carrying out the method according to the invention.

• a) Auftragen einer ersten Schicht aus pulverförmigem und/oder körnigem Material auf eine vertikal verstellbare Aufbauplattform,
• b) selektives Tränken der ersten Schicht mit einem Bindemittel entsprechend der Gestalt der herzustellenden Verbundstruktur, und
• c) schichtweises Auftragen zumindest einer weiteren Schicht aus pulverförmigem und/oder körnigem Material, wobei eine jede weitere Schicht entsprechend der Gestalt der herzustellenden Verbundstruktur selektiv mit besagtem Bindemittel getränkt und die Aufbauplattform um die jeweilige Schichtdicke abgesenkt wird, wobei entweder
• d1) eine jede selektiv mit Bindemittel getränkte Schicht aus pulverförmigem und/oder körnigem Material oder
• d2) ein aus zwei oder mehr selektiv mit Bindemittel getränkten Schichten aus pulverförmigem und/oder körnigem Material bestehender Schichtaufbau infolge Wärmeeintrag selektiv verfestigt wird, und wobei sich
• e) der Wärmeeintrag durch Bestrahlung mit hochenergetischen Mikrowellen ergibt und die Aufbauplattform als Mikrowellenantenne zumindest einer Mikrowellenvorrichtung verwendet wird.

The process for producing a three-dimensional composite structure according to a printing process is thus characterized by the following steps:

• a) applying a first layer of powdery and / or granular material to a vertically adjustable build-up platform,
• b) selectively impregnating the first layer with a binder according to the shape of the composite structure to be produced, and
• c) layer-by-layer application of at least one further layer of pulverulent and / or granular material, wherein each further layer is selectively impregnated with said binder according to the shape of the composite structure to be produced and the construction platform is lowered by the respective layer thickness, either
• d1) any layer of pulverulent and / or granular material which is selectively impregnated with binder or
• d2) a layer structure consisting of two or more layers of pulverulent and / or granular material selectively impregnated with binder is selectively solidified as a result of heat input, and wherein
• e) results in the heat input by irradiation with high-energy microwaves and the build platform is used as a microwave antenna at least one microwave device.

It is proposed a method for producing a three-dimensional composite structure according to a printing method, which allows an increased production turnover with minimal effort.

The subclaims describe preferred developments or refinements of the invention.

Thereafter, a mineral sand, in particular quartz and / or corundum sand, is advantageously used as a powdery and / or granular material, which is extremely inexpensive and easy to process. The binder used is preferably a water-based or solvent-based binder, in particular an inorganic binder, which also results in minimized costs. As the invention further provides, the structure of the individual, impregnated with a binder layers for producing the composite structure is preferably carried out in an at least on the order side of the build platform open and metallic shielded housing, the housing with respect to the step e) only during the heat input through Irradiation with high-energy microwaves is closed for metallic shielding. As a result, the production cost is particularly simplified since the means for applying the powdery and / or granular material and for the selective soaking thereof can be arranged outside of the housing. Particularly advantageous is the above method for producing a sand core, in particular lost sand core, used for foundry purposes.

The device for carrying out the method is characterized in that a metal-shielded housing is provided in which a vertically adjustable build platform for layered on the same applied powdery and / or granular material is arranged, wherein at least one arranged outside of the housing, but on the Build-up platform translationally and parallel to the same adjustable first means for applying coating of said powdery and / or granular material, at least one disposed outside the housing, but on the build platform translationally and parallel to the second adjustable means for selectively soaking each applied layer powdery and / or granular material with a water- or solvent-based binder, and at least one microwave device for drying the selectively soaked layers of powdery and / or granular Materia 1, which microwave device has a microwave antenna formed by the build platform. As a result, an apparatus for producing a three-dimensional composite structure according to a printing method is proposed, which allows an increased production turnover with minimal effort.

According to an advantageous development of the device according to the invention, the at least one adjustable second device has at least one cover element for closing the metal-shielded housing, whereby the environment of the housing is protected against adverse radiation exposure. In addition, this measure ensures optimal heat distribution and drying of the layers impregnated with binder or of the impregnated layer structure. In this case, the at least one cover element is preferably connected to the at least one adjustable second device such that the housing is closed by means of the at least one cover element in an operating position of the second device following the impregnation of at least one last applied layer of pulverulent and / or granular material ,

• 1 bis 4 die erfindungsgemäße Vorrichtung in einer äußerst schematischen Schnittdarstellung mit der Verdeutlichung einzelner Verfahrensschritte zur Herstellung einer dreidimensionalen Verbundstruktur nach einem Druckverfahren gemäß einer ersten vorteilhaften Ausführungsvariante der Erfindung,
• 5 und 6 die erfindungsgemäße Vorrichtung in einer äußerst schematischen Schnittdarstellung mit der Verdeutlichung einzelner Verfahrensschritte zur Herstellung einer dreidimensionalen Verbundstruktur nach einem Druckverfahren gemäß einer zweiten vorteilhaften Ausführungsvariante der Erfindung, und
• 7 die erfindungsgemäße Vorrichtung in einer äußerst schematischen Schnittdarstellung mit der Illustration der nach den beiden Ausführungsvarianten hergestellten fertigen Verbundstruktur.

The invention will be explained in more detail with reference to the embodiments schematically illustrated in the drawings. However, it is not limited to these, but covers all embodiments defined by the claims. Show it:

• 1 to 4 the device according to the invention in an extremely schematic sectional view with the clarification of individual process steps for producing a three-dimensional composite structure according to a printing method according to a first advantageous embodiment of the invention,
• 5 and 6 the device according to the invention in an extremely schematic sectional view with the explanation of individual process steps for producing a three-dimensional composite structure according to a printing method according to a second advantageous embodiment of the invention, and
• 7 the apparatus of the invention in an extremely schematic sectional view with the illustration of the finished composite structure produced according to the two embodiments.

According to the 1 to 7 has said device for producing the in 7 shown finished composite structure 1 after a printing process or 3D printing a lift table 2 on, which by means of a drive 3 , in particular electric drive, vertical or height-adjustable. On the lift table 2 is a building platform 4 arranged. The construction platform 4 is in a metallic shielded case 5 the device is guided vertically adjustable. Structural side of the construction platform 4 , ie, upwards is the case 5 initially open. On the construction platform 4 is in operation of the device through the opening 5a of the housing 5 through a powdery and / or granular material 6 applied.

According to this embodiment, the powdery and / or granular material 6 formed by a mineral sand, in particular a quartz and / or corundum sand, from which with the device according to the invention and the method according to the invention, by way of example only, a sand core, in particular a lost sand core, is or will be produced for foundry purposes.

Outside the case 5 are shift guides 7 for a translational and parallel to and over the build platform 4 adjustable first device 8th for the layered application of said powdery and / or granular material 6 on the construction platform 4 as well as for translational and parallel to and over the build platform 4 adjustable second device 9 for selectively soaking each applied layer 10 made of powdery and / or granular material 6 with a particular inorganic binder 11 intended. The binder 11 is a preferred water or solvent based binder 11 (??? - please give an example). From the selective soaking of the layers 10 powdery and / or granular material 6 arise per shift 10 Printed (soaked) layer areas, so to speak 10a and unprinted (non-saturated) layer areas 10b ,

In addition, the device has a microwave device 12 to dry selectively with binder 11 soaked layers 10 made of powdery and / or granular material 6 , The microwave device 12 is formed by a so-called magnetron, which comprises a known per se and therefore not shown in detail vacuum runtime tube for generating electromagnetic radiation in the microwave range. The microwave device 12 is also present on the lift table 2 but outside the case 5 arranged and with the preferred metal build platform 4 electrically connected such that these as a microwave antenna 13 the microwave device 12 acts.

Like that 1 to 7 can still be seen, has the adjustable second device 9 for selectively soaking each applied layer 10 made of powdery and / or granular material 6 a cover element 14 for closing the metal-shielded housing 5 on. The cover element 14 is so with the said second device 9 connected, that in a the impregnation of at least one last applied layer 10 made of powdery and / or granular material 6 with the binder 11 following operating position of the second device 9 the housing 5 by means of the cover element 14 at least with regard to the restriction of the electromagnetic radiation to the interior of the housing 5 is closed.

Hereinafter, the inventive method for producing a particular in 7 extremely schematically shown finished composite structure 1 explained by a printing method with reference to the device described above.

Variant 1 (FIGS. 1 to 4):

Thereafter, according to a first advantageous method for producing a three-dimensional composite structure 1 or for operating the device according to the invention by means of the first device 8th for layered application of powdery and / or granular material 6 first a first shift 10 from said material 6 , Exemplary quartz and / or corundum sand as foundry sand for the production of a lost sand core for foundry purposes, on the built-up by a layer thickness down building platform 4 applied. According to 1 becomes the first institution 8th from a first operating position 15 respectively initial position translational and parallel to and over the build platform 4 in a second operating position 16 in the direction of getting in their first operating position 17 respectively starting position located second device 9 to selectively soak the layer 10 with binder 11 method.

After that, according to 2 the first device 8th in her first operating position 15 reduced (see dashed line of the first device 8th ). Simultaneously with this action or following it becomes the second facility 9 also translational and parallel to and over with the first layer 10 from said material 6 acted upon construction platform 4 led away, according to the desired shape of the composite structure to be produced 1 selectively said binder 11 on the first layer 10 applied and these selectively with binder 11 is drowned (see dashed line of the second device 9 ). The second device 9 reaches a second operating position 18 next to in their first operating position 15 located first device 8th (see. 3 ).

As already described above, with the second device 9 a cover element 14 to the Closing the metallic shielded housing 5 connected so that in the impregnation of the applied layer 10 made of powdery and / or granular material 6 with the binder 11 following second operating position 18 the second device 9 the housing 5 by means of the cover element 14 is closed.

When this condition is reached, the first becomes selective with binder 11 soaked layer 10 powdery and / or granular material 6 or the printed layer area, so to speak 10a the layer 10 solidified by heat input selectively. The heat input results from irradiation with high-energy microwaves 19 the microwave device already described above 12 , wherein the metal building platform 4 as a microwave antenna 13 acts (cf. 3 ). Subsequently, the second device 9 including cover element 14 back to her first operational position 17 respectively initial position returned and therefore the housing 5 reopened (cf. 4 ).

This is followed by other similar process steps for the layered representation of the desired shape of the composite structure to be produced 1 on, with the build platform 4 layer by layer is still moved down. The result is a finished, consolidated composite structure 1 as they are in 7 is shown.

Variant 2 (Figures 5 and 6):

The in the 5 and 6 illustrated second variant of the method for producing a three-dimensional composite structure 1 or for operating the device according to the invention differs from the previously described first variant essentially in that initially a complete layer structure 20 of two or more selectively with binder 11 soaked layers 10 powdery and / or granular material 6 is created by the first and second means as described above 8th . 9 with appropriate material delivery translational and parallel to and over the build platform 4 be guided away and thus, so to speak, printed and unprinted layer areas 10a . 10b each shift 10 be created.

Is, as in 5 shown, the layer structure 20 completed and is the second facility 9 to selectively soak the last layer 10 powdery and / or granular material 6 with binder 11 in their second operating position 18 in which the housing 5 by means of the cover element 14 is closed, the entire layer structure 20 selectively solidified. Again, the heat input results from irradiation with high-energy microwaves 19 the microwave device already described above 12 , wherein the metal building platform 4 as a microwave antenna 13 acts (cf. 6 ). The result is a finished, consolidated composite structure 1 as they are in 7 is shown.

LIST OF REFERENCE NUMBERS

1

composite structure

2

Lift table

3

drive

4

build platform

5

casing

5a

opening

6

material

7

displacement guide

8th

first device

9

second device

10

Layer (material 6)

10a

printed layer area

10b

unprinted layer area

11

binder

12

microwave device

13

microwave antenna

14

cover

15

first operating position (first device 8)

16

second operating position (first device 8)

17

first operating position (second device 9)

18

second operating position (second device 9)

19

microwave

20

layer structure

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

• CN 203282709 U [0002]
• US 2015/0054204 A1 [0002]
• US 2016/0096327 A1 [0002]
• US 2016/0297142 A1 [0002]
• DE 10235434 A1 [0002]

Claims (8)

Method for producing a three-dimensional composite structure (1) according to a printing method, comprising the following steps, a) applying a first layer (10) of pulverulent and / or granular material (6) to a vertically adjustable build-up platform (4), b) selectively impregnating the first layer (10) with a binder (11) according to the shape of the composite structure (1) to be produced, and c) layer-by-layer application of at least one further layer (10) of powdery and / or granular material (6), wherein each further layer (10) according to the shape of the composite structure (1) selectively impregnated with said binder (11) and the build platform (4) is lowered by the respective layer thickness, either d1) a layer (10) of pulverulent and / or granular material (6) or each selectively impregnated with binder (11) or d2) a layer structure (20) consisting of two or more layers (10), which have been selectively impregnated with binder (11), of pulverulent and / or granular material (6) is selectively solidified as a result of heat input, and wherein e) the heat input by irradiation with high-energy microwaves (19) results and the building platform (4) as a microwave antenna (13) at least one microwave device (12) is used. Method according to Claim 1 , characterized in that a mineral sand, in particular quartz and / or corundum sand, is used as the powdery and / or granular material (6). Method according to Claim 1 or 2 , characterized in that the binder (11) is a water- or solvent-based binder (11), in particular inorganic binder (11), is used. Method according to one of the preceding claims, characterized in that the structure of the individual, with a binder (11) impregnated layers (10) for producing the composite structure (1) in an at least on the order side of the building platform (4) open and metallic shielded housing ( 5), wherein the housing (5) with respect to the step e) during the heat input (19) is closed by irradiation with high-energy microwaves for metallic shielding. Method according to one of the preceding claims for producing a sand core, in particular lost sand core, for foundry purposes. Device for carrying out the method according to one of the preceding claims, with a metallic shielded housing (5) in which a vertically adjustable build-up platform (4) for layer by layer on the same applied powdery and / or granular material (6) is arranged, with at least one outside the housing (5) arranged, but on the build platform (4) translationally and in parallel to the first adjustable means (8) for coating application of said powdery and / or granular material (6), arranged with at least one outside of the housing (5) but translationally via the building platform (4) and parallel to the same adjustable second means (9) for selectively impregnating each applied layer (10) of powdered and / or granular material (6) with a water or solvent based binder (11), and with at least one microwave device (12) for drying the se selectively soaked layers (10) of powdery and / or granular material (6), said microwave device (12) comprising a microwave antenna (13) formed by the building platform (4). Device after Claim 6 , characterized in that the at least one adjustable second device (9) has at least one cover element (14) for closing the metal-shielded housing (5). Device after Claim 7 , characterized in that the at least one cover element (14) is connected to the at least one adjustable second device (9) in such a way that at least one last applied layer (10) of powdered and / or granular material (6) is impregnated with the Binder (11) following operating position (18) of the second device (9) the housing (5) by means of the at least one cover member (14) is closed.

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