Method and system for the additive manufacturing of a three-dimensional component

Abstract

The invention relates to a method for the additive manufacturing of a three-dimensional component from a bulk material (9), wherein a number of small pieces (21, 22), which have a similar shape and / or size, are separated from the bulk material (9)and / or organised, wherein the separated and / or organised pieces (21, 22) are arranged in a row before being fed to a print head (6) for three-dimensional printing; for separation, the bulk material (9) is introduced into a rotatable drum (30), and the pieces (21, 22) of the bulk material (9) are arranged, by way of a rotation of the drum (30), in a row in a separation device (40) arranged on an inner wall (33) of the drum (30). The invention further relates to a system (1) for the additive manufacturing of a three-dimensional component from a bulk material (9), wherein the system (1) comprises a rotatable drum (30) having a separation device (40); the separation device (40) arranged on the inner wall (33) of the rotatable drum (30) has a first section (41) for pre-separating the pieces (21, 22) in a first region (31) of the drum (30) and said section transitions into a cylindrical section (42) of the separation device (40) in a second region (32) of the drum (30).

Description

[0001] Description

[0002] title

[0003] Method and system for the additive manufacturing of a three-dimensional component

[0004] The invention relates to a method and a system for the additive manufacturing of a three-dimensional component from a bulk material.

[0005] State of the art

[0006] German patent application DE 10 2013 217 825 A1 discloses various methods for the rapid prototyping or small-batch production or individual component manufacturing, which involve the use of so-called 3D printers. These printers can print any type of plastic part with minimal effort. The following techniques are distinguished: stereolithography (SLA), selective laser sintering (SLS), fused deposition modeling (FDM), laminated object manufacturing (LOM), and 3D printing (3DP). In known 3D printers, filament plastic is melted in an extruder and forced through a nozzle. The plastic exits the nozzle as a thin filament and is deposited onto a build plate. After a certain time, the deposited material cools and solidifies.By adjusting the extruder's movement relative to the base plate, any desired shape can be built up layer by layer using the resulting thin plastic filament. The extruder is moved according to a pattern relative to the base plate, which is generated by a computer based on an object template.

[0007] German patent application DE 10 2016 220 496 A1 discloses a method for the additive manufacturing of a three-dimensional component from a bulk material, wherein a number of small pieces having a similar shape and / or size are sorted and / or arranged from the bulk material. The sorted and / or arranged pieces can be removed from the bulk material.

[0008] The object of the invention is to simplify and / or improve the additive manufacturing of three-dimensional components from a bulk material.

[0009] Disclosure of the invention

[0010] The problem is solved in a method for the additive manufacturing of a three-dimensional component from a bulk material by providing a method and a system for the additive manufacturing of a three-dimensional component from a bulk material, wherein in the method a number of small pieces having a similar shape and / or size are sorted and / or arranged from the bulk material, wherein the sorted and / or arranged pieces are arranged in a row before being fed to a print head for three-dimensional printing, wherein the bulk material is introduced into a rotatable drum for sorting and that the pieces of the bulk material are arranged in a row in a sorting device arranged on an inner wall of the drum by rotating the drum.

[0011] The sorted and / or ordered small pieces are easier to process for the additive manufacturing of a three-dimensional component from the bulk material. The bulk material could be, for example, granules made of a thermoplastic material. It could also be granules made of a biological material, such as gelatin. In additive manufacturing, the sorted and / or ordered pieces are melted and advantageously applied layer by layer. After each layer has cooled and solidified, the next molten layer can be applied successively. Unlike conventional methods, the starting material is not supplied in the form of filaments or plastic wire, but as a disordered bulk material, particularly granules.Sorting and / or ordering the bulk material, especially granules, enables the direct use of individual pieces, particularly granule particles or grains. The unsorted bulk material, especially granules, is significantly cheaper in terms of acquisition costs, for example, by a factor of five to one hundred, especially compared to the use of plastic wire or filament. Furthermore, the bulk material, particularly in granule form, is available in far more variations than wire. Sorting and / or ordering the bulk material, especially granules, offers the advantage over using loose bulk material, particularly granules, that the size of the plasticizing unit used to melt the material can be significantly reduced.This in turn allows for a reduction in process forces, costs, damaging influences and the complexity of a system for the additive manufacturing of three-dimensional components from bulk material, especially from a thermoplastic polymer material or gelatin.

[0012] During sorting and / or aligning, small pieces of similar shape or size are advantageously separated and / or aligned. Separating and aligning the individual pieces allows even the smallest quantities of material to be plasticized or melted as needed, ensuring optimal processing. This prevents undesirable damage to the material, particularly thermoplastic materials or gelatin, caused by prolonged waiting times in the plasticizing unit. Furthermore, the starting material, in the form of sorted and / or aligned pieces, especially granules, can be ideally dosed to avoid unnecessary melting.The particularly gentle processing of the sorted and / or ordered small pieces allows for high quality and accuracy of the additively manufactured three-dimensional component during three-dimensional printing.

[0013] Furthermore, according to the invention, the sorted and / or ordered pieces are arranged in a row before being fed to a printhead for three-dimensional printing. Advantageously, the sorted and / or ordered pieces are strung together in a manner similar to that on a string of beads. Moreover, the method according to the invention eliminates the need for compressed air for sorting, thus enabling more economical operation of the system. More energy-efficient conveying can therefore be advantageously achieved.

[0014] Another preferred embodiment of the method is characterized in that the bulk material is fed in as randomly sorted granules. The randomly sorted granules are, for example, a thermoplastic material. The randomly sorted granules are much cheaper than specially sorted or processed granules.

[0015] In a further development of the process, impurities and / or pieces that have an undesirable size and / or shape are removed from the bulk material before the pieces are sorted, using a sieve device arranged on a wall of the drum.

[0016] Removing impurities and / or pieces of undesirable size and / or shape significantly improves the quality of the bulk material used as starting material. This has a positive effect on further processing, especially melting, as well as on the additive manufacturing of the three-dimensional component.

[0017] In a further training course, the sorted and / or ordered pieces are arranged in a tube-like or hose-like conveying device before being fed to a plasticizing unit and / or a printhead.

[0018] The tubular or hose-like conveying device is advantageously adapted to the shape of the sorted and / or ordered pieces. For this purpose, the conveying device essentially has the shape of a straight circular cylinder in which a multitude of the sorted and / or ordered pieces are held longitudinally in succession. From this device, the ordered pieces, in particular granules, can then be easily metered to the plasticizing unit and / or the printhead.

[0019] Furthermore, the invention comprises a system for the additive manufacturing of a three-dimensional component from a bulk material, according to the inventive method, wherein the system comprises a rotatable drum with a sorting device, wherein the sorting device arranged on the inner wall of the rotatable drum has in a first area of ​​the drum a first section for pre-singleting the pieces and this transitions in a second area of ​​the drum into a cylindrical section of the sorting device

[0020] In a further training, the drum has a sieve device on one wall for removing impurities and / or pieces that are of an undesirable size and / or shape.

[0021] Removing impurities and / or pieces of undesirable size and / or shape significantly improves the quality of the bulk material used as starting material. This has a positive effect on further processing, especially melting, as well as on the additive manufacturing of the three-dimensional component.

[0022] In a further development, the sieving device extends over the entire circumference of the drum. This advantageously ensures that impurities can be removed throughout the entire rotation of the drum.

[0023] The inventive method and system optimize the dosing of granules for further processing, such as extrusion or machining. Furthermore, by arranging the granules, precise dosing of color batches can be achieved, and the granules can advantageously be counted.

[0024] By conveying granules arranged in a tube, long distances can be advantageously covered. Furthermore, the sieving device advantageously facilitates the simple sieving of granules, i.e., the separation of fine particles as well as larger objects. Adapting the geometry of the sorting device, or the cylindrical tube, advantageously allows the use of granules with different geometric structures, such as triangular, quadrilateral, or any polygonal shapes. Further advantages, features, and details of the invention will become apparent from the following description, in which various embodiments are described in detail with reference to the drawing.

[0025] Brief description of the drawing

[0026] They show:

[0027] Fig. 1 is a block diagram illustrating a system for the additive manufacturing of a three-dimensional component from a thermoplastic material according to the state of the art.

[0028] Fig 2 shows a representation of a drum of a system according to the invention.

[0029] Description of the exemplary implementations

[0030] Figure 1 shows a simplified block diagram of a system 1 for the additive manufacturing of a three-dimensional component from a thermoplastic material applied in a molten state. A drying area is indicated by a rectangle 3, in which the thermoplastic material, in particular disordered granules 9, is first ordered and then, preferably dried, fed to a plasticizing unit 6.

[0031] The plasticizing unit 6 includes, for example, an extruder with a feed nozzle 7 through which ordered and dried granules are introduced. The plasticizing unit 6 includes a print head for three-dimensional printing at its lower, pointed end as shown in Fig. 1.

[0032] The ordered granules 21, 22 are melted in the plasticizing unit 6. The molten thermoplastic material can be metered, preferably layer by layer, via the print head at the lower, pointed end of the plasticizing unit 6 in order to additively manufacture or print a desired three-dimensional component in a manner known per se.

[0033] The randomly oriented granules 9 are taken from a container 8. For this purpose, a conveying unit 10 is connected to the container 8 containing the randomly oriented granules 9. The conveying unit 10 comprises a conveying tube 11, which, as shown at the top of Figure 1, is connected to the container 8. A conveying head 12 is arranged at one end of the conveying tube 11 facing away from the container 8. The conveying unit 10 can advantageously be combined with a metal separator.

[0034] The randomly oriented granules 9 are fed from the container 8 to a vibrating and / or shaking device 16 via the conveying head 12. A symbol 14 above the conveying head 12 indicates that the randomly oriented granules 9 are drawn from the container 8 into a vibrating pot 18 of the vibrating and / or shaking device 16, for example by means of a vacuum pump.

[0035] In the vibrating pot 18, the disordered granules 9 are vibrated and / or shaken to remove impurities 17 and / or granules of undesirable size and / or shape from the disordered granules in the vibrating pot 18. The removed impurities 17 and / or undesirable granules 9 are collected in a collection container 19, which is arranged below the vibrating pot 18 in Fig. 1.

[0036] The system 1 further includes a dosing unit 20 in the drying area 3. The dosing unit 20 is arranged between the vibrating and / or shaking device 16 and the plasticizing unit 6. In the dosing unit 20, individual pieces or granules 21, 22 are collected from the vibrating and / or shaking device 16 and aligned.

[0037] For this purpose, the metering unit 20 comprises a metering tube 23, the shape of which is adapted to the shape of the individual granules 21, 22. The metering tube 23 extends in a horizontal direction, i.e., parallel to a base on which the system 1 stands. At its right end (as shown in Fig. 1), the metering tube 23 is connected to the top of the vibrating pot 18. At its left end (as shown in Fig. 1), the metering tube 23 has a metering head 24, through which the ordered and aligned granules 21, 22 can be metered and dispensed to the plasticizing unit 6. Above the dosing head 24, a symbol 25 indicates that the granules 21, 22 can be drawn from the vibrating pot 18 or from the dosing tube 23 towards the filling nozzle 7 of the plasticizing unit 6, for example by means of a vacuum pump.

[0038] Fig. 2 shows a representation of a drum 30 of a system 1 according to the invention, wherein the system 1 is suitable for the additive manufacturing of a three-dimensional component from the bulk material 9. The system 1 comprises a rotatable drum 30 with a sorting device 40, wherein the sorting device 40, arranged on an inner wall 33 of the rotatable drum 30, has in a first region 31 of the drum 30 a first section 41 for pre-singleting the pieces 21, 22, or the granules 21, 22, and this transitions in a second region 32 of the drum 30 into a cylindrical section 42 of the sorting device 40.

[0039] Furthermore, the drum 30 has a sieve device 35 on a wall 34 for removing impurities 17 and / or pieces that have an undesirable size and / or shape. The sieve device 35 extends over the entire circumference of the drum 30.

[0040] The system 1 is suitable for carrying out a process, wherein the process is for the additive manufacturing of a three-dimensional component from the bulk material (9), wherein the number of small pieces 21, 22, which have a similar shape and / or size, are sorted and / or arranged from the bulk material 9, wherein the sorted and / or arranged pieces 21, 22 are arranged in a row before being fed to the print head 6 for three-dimensional printing, wherein the bulk material 9 is introduced into the rotatable drum 30 for sorting and the pieces 21, 22 of the bulk material 9 are arranged in a row in the sorting device 40 arranged on the inner wall 33 of the drum 30 by rotating the drum 30.

[0041] In one process step, impurities 17 and / or pieces of undesirable size and / or shape are removed from the bulk material 9 by means of a sieve 35 arranged on a wall 34 of the drum 30 before the pieces 21, 22 are sorted. In a further process step, the sorted and / or ordered pieces 21, 22 are arranged in a tubular or hose-like conveying device 50 before being fed to a plasticizing unit and / or a printhead 6.

[0042] The pieces 21, 22, or the granules, are located in the rotating drum 30, which is preferably inclined axially to the horizon at an angle W of 10° to 50°. The sorting device 40 is arranged on the inner wall 33 of the drum 30, the latter extending in a spiral shape in the form of a cylindrical tube 41, 42. The open end 41 of the sorting device 40, or of the cylinder tube 41, 42, is arranged in the first section 31 of the drum 30 and forms the first section 41 for pre-singling the pieces 21, 22, or the granules 21, 22. This first section 41 is located at approximately % of the height of the bottom 37 of the drum 30. The upstream semi-open cylinder tube 41 serves to pre-single the granules 21, 22. The diameter remains the same over the entire cylinder tube 41, 42. The first section 41 can also be called a pre-singler 41. To remove impurities 17, orTo remove the fine particles in the bulk material 9, the sieving device 35, which runs around the drum 30, is used. The recesses in the sieve have a slightly smaller diameter than the granules 21, 22, thus achieving optimal sieving performance.

[0043] When the drum reaches 30, or the rotating pot reaches approximately... 1When drum 30 is filled with bulk material 9, individual granules 21, 22 enter the pre-separator 41. Gravity and the rotation of the drum 30 convey these granules to the front of the pre-separator 41, or the cylinder tube. At the inlet of the cylinder tube 41, individual granules 21, 22 can thus slide one after the other into the cylinder tube 41, 42. Should any granules 21, 22 become wedged, this occurs outside the cylinder tube 41, causing them to fall off during the next half-turn of the drum 30. The spiral winding of the sorting device 40 and gravity then convey the granules 21, 22, which are lined up in the cylinder tube 41, 42, to the bottom 37 of the drum 30. There, the winding of the cylinder tube 41, 42 is guided to the axial axis of the drum 30 and then led via an outlet 36 from the drum 30 into the hose-like conveying device 50.The rotating cylinder tube 42 of the sorting device 40 is coupled at the outlet 36, for example via a sleeve, to the stationary conveying device 50 or the conveying hose.

Claims

Claims 1. Method for the additive manufacturing of a three-dimensional component from a bulk material (9), wherein a number of small pieces (21, 22) having a similar shape and / or size are sorted and / or arranged from the bulk material (9), wherein the sorted and / or arranged pieces (21, 22) are arranged in a row before being fed to a print head (6) for three-dimensional printing, characterized in that the bulk material (9) is introduced into a rotatable drum (30) for sorting and that the pieces (21, 22) of the bulk material (9) are arranged in a row in a sorting device (40) arranged on an inner wall (33) of the drum (30) by rotating the drum (30).

2. Method according to one of the preceding claims, characterized in that Impurities (17) and / or pieces that have an undesirable size and / or shape are removed from the bulk material (9) before the sorting of the pieces (21, 22) by means of a sieve device (35) arranged on a wall (34) of the drum (30).

3. Method according to one of the preceding claims, characterized in that the sorted and / or ordered pieces (21, 22) are arranged in a tubular or hose-like conveying device (50) before being fed to a plasticizing unit and / or a print head (6).

4. Plant (1) for the additive manufacturing of a three-dimensional component from a bulk material (9), according to a method according to one or more of the preceding claims, characterized in that The system (1) comprises a rotatable drum (30) with a sorting device (40), wherein the sorting device (40) arranged on the inner wall (33) of the rotatable drum (30) has in a first area (31) of the drum (30) a first section (41) for pre-separating the pieces (21, 22) and this transitions in a second area (32) of the drum (30) into a cylindrical section (42) of the sorting device (40).

5. Plant (1) according to claim 4, characterized in that the drum (30) has a sieve device (35) on a wall (34) for removing impurities (17) and / or pieces that have an undesirable size and / or shape.

6. Plant (1) according to claim 5, characterized in that the sieving device (35) is formed over the entire circumference of the drum (30).

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