DE102015002967A1 - 3D printing tool and 3D printing of bundles - Google Patents

Abstract

A 3D printing tool is configured to process 3D printing material 110, which melts by heating, thereby forming the workpiece 200, including a feeding unit 300 for feeding the 3D printing material 110 for 3D printing, and a radiant heater 400 for selectively heating the print material 200 sufficient to fuse the 3D print material 200 while the heated 3D print material 120 is being fed to the work piece 200 to be formed by the feed unit 300.

Description

The present invention relates to a tool for 3D printing, and more particularly to a 3D printing tool in which radiation heating is used to selectively heat 3D printing material. For example, defined by sequential addition / interconnection within a 3-dimensional workspace under automatic control.

background

3D printing has become increasingly important due to the ability to produce a wide range of different objects with just one machine. In this type of fabrication, the term printing refers to a growth process of the object by adding layers of material until the entire object is completed.

In one variant of 3D printing, each individual layer is formed by applying a layer of granules, which is subsequently sintered to the surfaces (eg by exposing a portion of the layer to heat), which will later be part of the object to be formed. Finally, the excess, non-sintered granules are removed so that the sintered coherent object comes to light.

This type of manufacturing leads to a number and problems. Initially, the sintering process limits the number of usable materials for such a process. In addition, the volume of the printed object is usually smaller than the total volume needed for the process. However, this excess material must be processed during printing, which affects the efficiency of the process. In addition, the workpiece often has to be further processed, the excess loose powder must be removed manually, and monitoring of the geometry produced can be difficult to monitor during the process. Also, in this process, the material is not continuously applied and bonded. The application and melting of the powder have to date been applied in two separate phases, which leads to a lower time and material efficiency.

Another conventional technique of 3D printing is known as filament extrusion (fused deposition modeling). Although technically comparatively simple and also manageable by untrained personnel, this process has significant weaknesses such as extremely low fabrication speeds of the workpiece, a rough surface due to extrusion traces of the individual layers, as well as a significant limitation of the usable materials to thermoplastic polymers. In addition, these materials can not be mixed gradually during the process and are hardly used for the fabrication of more complex or higher quality commercial products.

Certain basic requirements have grown to make 3D printing more economical and to make its potential available for use in a larger commercial and industrial scale. This is a substantial acceleration of fabrication, an increase in the quantity of available materials, and an increase in the potential dissolution of the fabrication process. Another future potential of 3D printing is that the goods produced have superior material quality compared to today's standards, while the labor required can be reduced to a minimum, which may allow an additional and crucial competitive advantage.

The present invention opens up new technologies for 3D printing and takes these requirements into account.

Summary of the invention

The present invention solves the previously discussed problems by offering 3D printing tools (heads) according to claim 1 or claim 7, as well as offering a 3D printing method according to claim 17. The claims herein relate to specifically advantageous implementations of the treated article of independent art Claims.

The present invention relates to a 3D printing tool (3D printing head) which is constructed to process printing material which is melted by heat and thereby used for molding a workpiece. The tool comprises a feed unit for providing the printing material for 3D printing, and a radiant heating element for selectively heating the printing material sufficient for the fusion of the printing material during the feeding of the material by the feeding unit.

The feeder unit can continuously provide the 3D printing material while it is being heated by the radiant heating element. However, the material may also be provided in the form of packages (bunching of the print material) such that the 3D print tool (3D print head) includes a pulsed feed unit around the print material in a series of packages to the workpiece add. These printed material packages can be heated by a radiant heater and are provided by a supply unit.

In contrast to conventional 3D printing machines (laser sintering, for example), in the present invention only the regions are supplied with print material where this is actually needed to form the workpiece. There is no need to provide an entire continuous material layer for the shaping of the workpiece. Since the present invention relies on selective heating, the 3D printing tool (3D printhead) may remain relatively cool while the 3D printing material is being heated by the radiation source. Since the heating is done directly in, or very close to, the 3D printing tool, the still heated or melted 3D printing material can be fused to the workpiece at the moment of contact with it (for example, after leaving the 3D printing tool).

The above-mentioned problem is solved by claim 1, by using radiation which selectively heats the 3D printing material. In general, this new concept allows the creation of process conditions for the molding of a workpiece that current techniques neither enable nor resist.

In a further embodiment, since the print material is selectively heated without significantly heating the 3D print tool itself (cold 3D printing), the tool consists of a feed unit and an exit unit which directs the 3D print material to the workpiece. Here, the radiant heater is positioned so that the 3D printed material on, or is heated within the outlet of the feed unit. Thus, the heated 3D printing material can not come into direct contact with the feeding unit of the 3D printing tool. This has the advantage that the 3D printing material within the 3D printing tool (or at least innherhalb a majority of the 3D tool) is heated only at the last moment when leaving the 3D printing tool, or on impact on the surface of the workpiece. Cool 3D printing materials (eg, filaments, powders) in the 3D printing tool are advantageous because they reduce the adhesion, friction between the 3D printing material and the inner wall of the 3D printing tool. In contrast, heated (melted) 3D printing materials would increase the friction or adhesion with the inner walls of the 3D printing tool and thus result in a process speed limit which is not overcome simply by increasing the pressure on the molten 3D printing material in the tool can be.

It must be made clear that the radiation which can be emitted by the radiant heater can be any kind of radiation (eg microwaves, laser radiation, particle radiation) which, due to its wavelength and intensity, is suitable for Printing material, or at least one to heat a portion of it. At the same time, the radiation can interact only weakly with the 3D printing tool, so that the 3D printing tool is not or only slightly heated. Therefore, another embodiment of the radiant heater is configured to emit electromagnetic radiation that heats the 3D printing material. However, the radiant heating can also heat the 3D printed material by means of particle radiation (for example radiation of electrons or protons or some other type of particles including ions).

In particular, the radiant heater allows a contactless heating to take place, which ensures that not the entire feeder unit or the 3D printing tool is heated, but only the corresponding 3D printing material. Therefore, in another embodiment, the radiant heater is configured such that the 3D printing material outside of the feeder unit is heated at a position at or near the workpiece. In addition, the radiant heater may be configured to heat the 3D printing material in an area near the workpiece, for example below the exit opening of the feeder unit, or at the end of the nozzle.

Depending on the material properties, the 3D printing material may have sufficient rigidity until it is heated by the radiation (for example up to the melting temperature). This allows the advantage that the filament can protrude a certain distance below the 3D printing tool, so that an accurate positioning for the process of material attachment is achieved without the 3D printing tool actually has to touch the workpiece.

In another embodiment, the delivery unit may include a nozzle unit. Additionally, in the case of using a filament (or any rod-like material), a drive (eg filament drive) may be provided to direct the 3D printing material to the nozzle unit. The material propulsion may consist of drive wheels to move the filament to the nozzle unit. In addition, the material propulsion speed can be adjusted to control the amount of material accumulation on the workpiece.

According to a further embodiment, the 3D printing tool includes a unit for Material storage, which is shaped to provide 3D printing material as a filament for the feed unit available. According to a further embodiment, the material storage is formed so as to provide the 3D printing material composed of a plurality of particles or fibers, or in another form, to the delivery unit. In addition, the 3D printing material can also be used in liquid form, such as water, glue, resin, or minerals. Curing can be by exposure to radiation.

In addition, the 3D printing tool may include facilities for the supply of compressed air, as well as one or more mixing units. The mixing units are designed to introduce particles of predetermined density or concentration into the air stream (or any other gas). In addition, the mixing units can be adjusted to set different particle densities or concentrations so that the resulting particle stream contains predetermined or variable particle ratios of the various particles (components of 3D printing materials).

The type of particles used for this process is essentially not limited. Any type of particle and particle mixture can be used for the 3D printing process. For example, the amount of particles may be powdery, granular, fibrous, or even liquid 3D printed matter, and the delivery unit may accordingly include tubular structures for directing the particulate matter. The feed unit can in turn contain a nozzle unit in order to apply the particulate material. Therefore, another embodiment of the delivery unit is configured to introduce the 3D printing material into a gas stream. The delivery unit may further include a cavity at a location where the 3D printing material is introduced into a gas stream. The cavity may be part of a cavity resonator so that the 3D dust-like printing material, which as powder, fibers, granules, etc. traverses the cavity is heated by the radiation within the cavity resonator. To ensure sufficient heating, the flow velocity of the particles or the dust can also be adjusted. This can be achieved, for example, by controlling the air pressure (airflow) which carries the dusty or powdery material, or by adjusting the diameter of the cavity, or adjusting the power of the electromagnetic radiation, or by adjusting the size of the area within its radiation and particles to interact. In another embodiment, a special powder throughput controller is included for precise control of particulate density / particle density.

For special applications, however, it may be advantageous if the heating power is provided mainly by the transport medium for the particle-like 3D printing materials (eg heated air flow). Accordingly, the present invention also relates to 3D printing tools that are configured to heat a particulate 3D printing material by the air stream itself, ultimately allowing the workpiece to be formed. Also, this 3D printing tool includes a feeding unit for supplying the printing material for 3D printing, and a mixing unit configured to mix the particulate printing material with the heated air (or other gas). Here, the air (or other gas) is heated sufficiently to heat the 3D printing material in succession so that, while being provided by the supply unit, it fuses with the work to be formed. In this implementation, heating by radiation is an additional option. However, the distance along which the particles are transported by the heated gas should be sufficiently long, or enough time allowed, for sufficient heat transfer from the air (gas) to the particles to ensure the 3D printing material. The combination of preheating (by air) and additional reheating by radiation opens the way to improved process control because, for example, the risk of premature cooling of the particles prior to contact with the workpiece is reduced.

Moreover, this implementation solves the above-mentioned problem that much more material is needed for the 3D printing process than is finally processed in the actual finished workpiece. Instead, the particles are sufficiently preheated so that they fuse securely with the workpiece in one place.

In this embodiment, the particles may be dispersed in a gas stream of any gas (eg, air, or inert gas), and the particles may be composed of a number of different materials which are mixed and introduced into the air stream. For example, after blending a first 3D printing material in air, another component of the 3D printing material may be introduced so that a composite of different materials may be blended in a predetermined or selected mixing ratio. The use of an inert gas may be of particular advantage for those applications where the workpiece is otherwise subject to an oxidation process (or other processes or chemical reactions which would be favored by the heating) and the inert gas in the environment could suppress any undesirable chemical reactions. On the other hand, the possibility of using oxygen or air to initiate a controlled oxidation process to alter the surface of the workpiece to a desired extent, possibly in conjunction with exposure to heat (eg, to harden the surface), is also contemplated. , Defining conductive elements and non-conductive sections (eg, oxide layer) may be advantageous for 3D printing of circuits and / or metal / oxide layers.

Although heating only one component of the number of materials may be sufficient, heating the transport gas stream allows the advantage that all components can be heated simultaneously. As a result, in this embodiment it is also possible to consider other 3D printing materials which otherwise can hardly be heated by radiation. Nevertheless, in another embodiment, the 3D printing tool may include an additional radiant heater suitable for heating at least one component of the 3D printing material. Accordingly, this embodiment can be combined with the previously illustrated embodiments. In another embodiment, the air heater allows preheating, and the radiant heating is still performed, but may be operated at a lower intensity to help phase change the particles when / where the particles strike the workpiece to fine-tune the 3D printing process to enable.

Air or any other gas may be heated before the particles are dispersed therein, or the particles may thereafter be heated (eg, by radiant heating). The application case where the particles themselves are heated, but not the surrounding air, allows the advantageous effect that upon impact of the 3D printing material on the workpiece, the resulting velocity difference between the particles on the workpiece and the passing air, a cooling effect of the still heated 3D Printing material comes about. It must be understood here that this cooling effect mainly occurs from the moment when the particles hit the workpiece, but not during the particles float in the air stream, during transport. During the particle flow, there is no or only a very small relative movement between the surrounding air and the particles of the particle stream. Since air is a good thermal insulator (as long as convection bypasses are suppressed), the air stream's air allows thermal isolation so the particles can barely cool. As a result, the air flow not only transports and insulates the heated particles, but also cools the particles upon impact on the workpiece, thereby accelerating the curing process.

The plurality of components may include, for example, carbon particles and a polymer. The radiation (wavelength) can be chosen such that, for example, only the carbon (for example microwave radiation) is heated, but not the polymer. In addition, the carbon dust can serve as a binder for the polymer powder because it transfers heat to the polymer and subsequently melts together. As a result, the molded workpiece will be made of a composite of various materials that form a solid through the 3D printing process. In comparing this process to conventional processes where all materials are heated equally, embodiments of the present invention additionally have the advantage of requiring less energy. In addition, the proportion of contained components can be freely adjusted, so that almost any material mixing ratio is possible. Even in a continuous process, without having to stop the 3D printing process.

Therefore, in another embodiment, the mixing unit is configured to mix different types of particles with an adjustable ratio with each other, wherein the radiant heater or the heated air is arranged so that at least a portion of the mixed powder is heated to the 3D Merge printing material after the deposition with the workpiece.

Many different materials are suitable for use in embodiments of the present invention. For example, the blending unit may be constructed to provide at least one of the following materials as 3D printing material: plastics, ceramics, metals, glass, minerals, polymers, or a mixture thereof, or any other material carried by the gas stream can. For example, the 3D printing material may also include droplets or resins with or without supplemental water droplets carried by the transporting gas and fusing (or hardening or setting) on the workpiece. Moreover, in a further embodiment, the mixing unit is constructed such that the ratio of the different particles can be adjusted while the feed unit provides the mixed 3D printing material.

In addition, the illustrated microwave heating can also be used for other materials, such as concrete on the Accelerate setting. Radiant heating may also be used for other hydraulic setting processes, or to accelerate or initiate catalytic or chemical curing or setting processes. Therefore, the described 3D printing process also covers possible further 3D printing materials, such as cementitious materials or liquids (for example, resins), which cure as a result of radiation exposure.

Other embodiments include a suspension ring to move the supply unit relative to the workpiece. For example, the delivery unit or nozzle may be gimbaled or mounted on a hexapod (Stewart Platform). The mounting bracket can be combined with a drive unit for at least one Cartesian axis, possibly part of a Cartesian axis configuration. For example, the 3D printing tool can be moved linearly along an axis parallel to the workpiece while being rotated back and forth across an axis, covering a larger area of the workpiece. The support bracket or hexapod may also be configured such that the delivery unit can be rotated in two different independent directions and thereby direct material flow (particle flow) in two or more transverse directions without having to move the entire delivery unit over the surface of the workpiece ,

Cardanic suspension provides the following advantages: The 3D printing tool can contain a material store of some mass, or the mixing unit and radiant heater alone can be too heavy to be accelerated quickly, such as inscribing and covering the workpiece geometry in a short time Would require time. Therefore, it may be difficult for the 3D printing tool to move quickly along a complex path above the surface of the workpiece. When the cardanic suspension is used, coarse positioning can be done by means of the Cartesian axis configuration or a robotic arm, while the fine positioning is done by means of the nozzle mounted on the gimbal or hexapod. Global and fine positioning of the 3D printing tool could be coordinated. This allows a fast 3D printing process while reducing the mechanical stress that would occur when the tool with its higher moment of inertia would have to be moved over the surface of the workpiece with rapid changes in speed and directional changes.

In addition, the gimbal suspension allows the possibility to distribute the material locally with different intensities. For example, by changing the speed of the Cartesian motion (translation) along an axis, the thickness of the layer attachment can be varied. Specifically, the material may be applied along a zig-zag motion path while the axis configuration moves along a straight line. This speeds up the 3D printing process because a larger area can be covered with only one path of travel along an axis. Furthermore, it is possible for the air stream to be concentrated (for example along the workpiece mounting direction) or divergent (for example along a surface for fine machining). The same applies to the electromagnetic radiation. Concentration or divergence can be achieved by means of a corresponding nozzle assembly which produces a dispersion angle along which the particle stream is distributed.

In another embodiment, the delivery unit includes means for supplying additional cold air, wherein the cold air flow is directed in a direction other than the radiation heated particles or filament. This allows subsequent cooling of the workpiece by cool air to accelerate after accumulation of material by the particle flow to the curing process of the workpiece. It is also possible to heat the workpiece or a part thereof in advance of the impact of the particles on the material layer. This allows the advantage of aiding the binding of the particles or fibers to the workpiece as the particles more readily fuse with the top layer of the surface of the workpiece and bond to the workpiece.

The 3D printing tool may include a control unit with which a plurality of the parameters on which the 3D printing process depends can be controlled. For example, the control unit may be constructed so as to control the amount of particles to be mixed with air, or the ratio of the various particles. In addition, the control unit may be constructed to control the pressure of the compressed air supplied to the mixing unit. In addition, the control unit may be constructed to control the temperature of the heated particles of the particle stream. The temperature of the particles can be determined by measuring the heat radiation of the heated particles. The amount of heat can be regulated by means of radiation heating, for example by varying the radiation intensity. In addition, the control unit may be constructed to control the speed by which the 3D printing tool travels along the surface of the workpiece. It is also possible to establish a control loop in spite of the necessary Complexity of the 3D printing process to achieve process stability.

In particular, in another embodiment, the control unit is configured to control at least the following: the supply of compressed air to the feed unit, the heating by the radiant heating, the density of at least one component of the 3D printing material, and consequently the composition of the work piece ,

The present invention also relates to a filament bundle which is used as 3D printing material in a 3D printing tool. The filament bundle may include: a core; and at least one filament wound around the core (eg, spiral). The filament may comprise a core of a particular material and wrapped filament, wherein at least one material is different from the material of the core. In addition, one filament can have a certain material and another filament another material. Both can be wrapped around the core.

Filament bundles are particularly advantageous when combined with a radiant heater from a certain distance. For example, it is possible to heat the filaments, locally, only at certain locations or points without heating a whole region, since the nozzle itself hardly has a thermal inertia. Therefore, the properties of the filament (for example, either in a molten state or in a flexible state) can be changed quickly, so that the workpiece can be produced with regionally different physical properties (eg partially flexible workpiece at certain points). The flexibility can accordingly be adapted to the requirements of the product design. In particular, it becomes possible to print textile-like materials with flexibility along at least one axis.

The present invention further relates to a method of 3D printing by the following steps: supplying the 3D printing material for printing; And selectively heating the printing material by irradiating the printing material with a radiation sufficient to fuse the printing material while the printing material is being fed to the workpiece to be molded. So that the printing material combines by heating or fuses to form the workpiece (object).

This process may also be implemented, at least in part, in a software or computer program, the sequence of individual steps not being critical to achieving the desired effect.

Short description of the illustrations

Various embodiments of the present invention will now be described by way of example only, and with reference to the accompanying drawings.

1 Represents a 3D printing tool according to an embodiment of the present invention;

2 Figure 1 illustrates an embodiment of the present invention based on a filament used as 3D printing material;

3 Provides a reduced friction guide means for the filament according to an embodiment;

4 Represent further embodiments for different radiant heaters;

5 Illustrate embodiments for various filaments for 3D printing;

6 Illustrate embodiments of the filaments formed as bundles;

7 Figure 5 illustrates another embodiment of the bundled filaments;

8th Represent an embodiment of a radiant heating of a particle stream in a chamber;

9 Illustrate further embodiments for the use of a particle stream to print the workpiece 3D;

10 Represent a further embodiments for the 3D printing tool;

11 Illustrate embodiments with feedback control;

12 Illustrate further embodiments with additional optional components;

13 Illustrate embodiments having a pressurized material storage chamber;

14 Illustrate embodiments for the 3D printing tool with a microwave heater;

15 Represent embodiments for a radiation heating of the particle stream;

16 Illustrate how the preheated particles and / or fibers combine to form the workpiece;

17 Illustrate two possible velocity distributions of particles in a stream of air;

18 Illustrate embodiments with an additional rotatable nozzle;

19 Represents a closed environment for the 3D printing tool according to further embodiments;

20 Represents an example compilation of nozzles / heaters which is controlled by a central controller according to further embodiments;

21 Represents a method for 3D printing according to an embodiment of the present invention.

Detailed description

1 Represents a 3D printing tool according to the present invention. The 3D printing tool is constructed by 3D printing material 110 to process, which melts by heating and thereby the workpiece 200 shaped. The tool consists of a feed unit 300 around the 3D printing material 110 the 3D printing process (production of 3D objects) to supply, as well as a radiant heater 400 for the selective heating of the 3D printed material 200 , enough to fuse the 3D printing material while the heated 3D printing material 120 through the feeding unit 300 the workpiece to be formed 200 is supplied.

2 Shows a 3D printing tool according to an embodiment of the present invention, wherein the 3D printing material 110 represents a filament, which is a radiation 120 is heated. The 3D printing tool contains a filament memory 105 , a filament drive 360 , a filament guide 370 and a microwave generator 410 , The filament storage 105 saves the filament 110 which is the filament drive 360 is supplied, which devices for propelling the filament 110 contains. After passing the filament guide 370 becomes the filament 110 through the microwave generator 410 heated, which is so constructed by a microwave radiation 120 to produce, which to the filament 110 is directed. The heated filament becomes the workpiece 200 fed to form a 3D printed object. The microwave generator 410 is designed in this embodiment to deliver the radiation so that the filament 110 outside the filament guide 370 (which part of the feeder unit 300 from 1 can be) to heat, or at a position where the filament 110 in contact (or shortly before) with the workpiece 200 comes to shape the three-dimensional print.

The microwave generator 410 is an example of radiant heating 300 out 1 , and the filament drive 360 as well as the filament guide 370 are part of the feeder unit 300 , The microwave generator 410 , the filament drive 360 and the filament guide 370 are in a 3D printing tool 500 integrated, which is mounted for example on a robot arm, which is built up the filament 110 over a surface of the workpiece 200 to move to thereby form the three-dimensional workpiece. Several layers of deposited material of the workpiece 210 can be produced by moving the 3D printing tool over the workpiece many times.

The filament drive 360 For example, it may contain two rollers which rotate in opposite directions and the driving force for the filament 110 deploy once the filament 110 is clamped between the two rotating rollers. A motor can drive the rollers such that the filament 110 at a predetermined speed for filament guidance 370 is moved.

In further embodiments, the radiant heating 400 be constructed to emit high-energy electromagnetic radiation such as γ-radiation or particle radiation, or any other type of radiation which is suitable sufficient energy in the 3D printing material 110 and through the 3D printed material 110 is recorded.

3 provides another filament guide 380 according to another embodiment. In this embodiment, the filament guide contains 380 roller guides 330 around the filament 110 to guide so that the filament 110 not in (direct) contact with other surfaces or components of the filament guide 380 (apart from the roller guides 330 ) comes. One or more roller guides 330 can be along the direction of movement of the filament 110 be attached to the filament 110 to the outlet of the filament guide 380 to lead without being in contact with the inner surface of the filament guide 380 get. This allows the roller guides 330 the advantage of reducing the friction between filament 110 and the filament guide 380 ,

The filament guide 380 can furthermore a filament propulsion wheel 320 included with a motor 340 is coupled to the filament Vortriebsrad 320 drive. In addition, a counter-pressure wheel 350 on the opposite side of the filament propulsion wheel 320 be used so that the filament 110 between the filament propulsion wheel 320 and the back pressure wheel 350 is seized. When there is enough pressure, the filament will become 110 by rotation of the filament propulsion wheel 320 , to the workpiece 200 emotional.

Also, this embodiment includes a radiant heater 410 which the 3D printing material or the filament 110 For example, irradiated with a microwave radiation, which is suitable from the 3D printing material (the filament 110 ) to be absorbed. In addition, in this embodiment, a microwave conductor (cavity) conducts 420 with a microwave outlet 430 at an outlet of the filament guide 380 , the radiation on the filament 110 , The filament 110 Can be heated before it is on the workpiece 200 is attached, or at a point where the filament 110 with the workpiece 200 comes into contact.

The filament 110 may for example consist of a carbon-polymer composite. In addition, the filament guide 380 in a housing 310 be recorded. The housing 310 can with the radiation generator 410 by means of a fitting piece 520 can be connected, and can with a central support 510 (eg parallel to the filament 110 ) to a Cartesian axis configuration connecting the 3D printing tool over the workpiece 200 positioned or moved.

All other components of this embodiment are similar to the embodiment of FIG 2 so that a repetition of the description is omitted here. Further structural details of the filament will be related later 6 and 7 described.

4a and 4b show further embodiments with different radiant heaters.

at 4a becomes the filament 110 heated by use of microwave radiation, which in turn by a microwave generator 410 is generated and by a microwave conductor 420 is directed. The microwave generator 410 is in turn (as in 3 ) to a connection 520 coupled, which the microwave generator 410 with the drive unit 380 combines. The connection 520 is in turn to the Cartesian axis configuration 510 connected to the 3D printing tool above the workpiece 200 to move.

The feeder unit 300 as in 1 introduced, contains in this embodiment, a Filamentzuleitung 305 , a filament propulsion wheel 320 , a counterpressure wheel 350 , and a filament outlet 395 , The filament propulsion wheel 320 can turn to an engine 340 coupled, which is the filament propulsion wheel 320 drives around the filament 110 the workpiece 200 to move against. To the friction between filament 110 and the feeder unit 300 are projections and niches along the path of movement of the filament 11 formed so that the filament 110 only limited contact with the inner surfaces of the feed unit 300 Has. The contact surface between filament 110 and feeding unit 300 is minimized or at least reduced.

The microwave radiation 440 which from the microwave conductor 420 is guided, heats the filament 110 shortly before or at the moment of contact with the workpiece 200 ,

4b represents a further embodiment for the radiant heater 400 as in 2 introduced in this embodiment includes the radiant heater 400 a laser emitter 450 which is configured to emit laser radiation of a suitable wavelength. The laser radiation becomes a radiation protection 480 (For example, a tube with shielding effect) passed, which contains a curved section where a mirror 470 the emitted laser radiation of the emitter 450 reflected to the radiation to the filament 110 to guide to a position where the filament 110 the outlet 395 the feed unit 300 has left, or where it comes in contact with the workpiece.

The feeder unit 300 is identical to the one in 4 is shown so that a repetition can be avoided here.

The radiation, for example microwave radiation and / or laser radiation, can be selected such that the radiation is suitable, the filament 110 , or at least a portion or constituents of the filament 110 to heat it to the remaining material of the workpiece 200 to merge to form the three-dimensional workpiece. As described in more detail below, the filament 110 consist of several components or components, wherein at least one of the various components can absorb the radiation (microwaves, lasers), thereby the filament 110 to heat and thus also the remaining components or components to heat, which were not directly heated by the radiation.

5a and 5b show embodiments in which composite filaments are processed by the 3D printing tool. The filament 110 For example, is again heated by microwave radiation, which by a microwave generator 410 is generated by the filament drive 360 moved, and through the filament guide 370 guided. The filament 110 This embodiment consists of several components, wherein at least one of these components is heated by microwave radiation.

In the illustrated embodiments, the workpiece is 200 however, it is not formed as a fully hardened block, but only partially, and is thereby partially flexible, due to the different patterns of the workpiece 200 is pictured. Therefore, the workpiece contains 200 unirradiated areas 222 and irradiated areas 221 , wherein the type of irradiation, for example, refers to microwave radiation and / or laser radiation. The non-irradiated areas 222 are not hardened or not with the rest of the workpiece 200 fused, and can, for example, flexible areas of the workpiece 200 define. On the other hand, the irradiated areas 221 hardens, or with other areas of the workpiece 200 fused and therefore give the workpiece 200 a certain degree of rigidity. Since the heating is outside the filament guide 370 , close to the workpiece 200 is done, the switch between heating and non-heating can be done quickly, so that the irradiated areas 221 precise on, or in the workpiece 200 can be positioned.

Both embodiments differ in the use of different filaments 110 which are used for the 3D printing process. at 5a a bundle of similar filaments is used, where egg 5b a filament bundle is used which contains various materials. Again, the radiation and filament bundle material is selected such that the generated radiation is sufficient for the filament 110 to heat enough for this process.

6a and 6b show an embodiment of the filament 110 as a bundle 105 , in which 6a a bundled filament 105 before exposure to radiation, and 6b represents the deformation by radiation exposure. The bundled filament shown 105 may be flexible and at least one thermoplastic filament 106 included, which with a thermoplastic core 109 combined. The thermoplastic core 109 can be in central position of the bundle 105 and the thermoplastic filament (s) 106 surround the thermoplastic core 109 (for example, spiral).

As in 6b shown, deforms the filament bundle 105 when heated by the radiation 440 , The radiation 440 creates, for example, a transition region 125 from the molten to the cooler deformable state, and after complete cooling, the filament can form a rigid thermoplastic filament 129 become. As a result of heating and cooling, the core can 129 , and the formerly surrounding filament are homogeneously fused.

7a and 7b show a further embodiment for the filament bundle 105 which in turn can be flexible. The bundle 105 may according to this embodiment of one or more thermoplastic filaments 106 consisting of a tensile filament bundle 111 surrounded by a spiral. Therefore, the gist of the embodiment becomes 7 in contrast to the thermoplastic core 109 out 6 , from a bundle of tensile filaments 111 represents. Again, after heating the filament bundle 105 with radiation 440 , a transition region 125 formed from molten to cooler plastic. Finally, the tensile core 121 from the molten and re-hardened thermoplastic 127 wrapped, which has a certain rigidity. Again, it is possible to control the heating such that stiff areas (heated and cooled areas) are created only at foreseen areas or locations.

8th and 18 show further embodiments wherein, instead of a filament, a particle stream is used as 3D printing material. The particles can be heated again by a radiation, which may consist of microwaves and / or laser radiation and / or particle radiation.

In embodiment too 8a is the heating of the particle stream by radiation in a chamber 307 carried out.

The particle flow is generated as follows. The 3D printing tool consists of a compressor 602 to compress the gas (eg air) and a particle store 603 for holding the particles which are to be used as 3D printing material. The compressor 602 and the particle store 603 can be inside an optional stationary installation 530 be arranged. The compressor 602 is with a mixing unit 610 by means of pipes 616 connected, which a flow direction for the gas flow 617 specify which of the compressor 602 is produced. The particle store 603 is to the mixing unit 610 connected by means of a tube which is designed to be the particles which in the particle storage 603 are stored, to the mixing unit 610 to direct where the air of the compressor 602 with the particles of the particle memory 603 is mixed. After mixing air and particles, the produced mixture becomes a particle flow heating nozzle 371 directed.

The embodiment too 8a contains a particle flow heating nozzle 371 with a radiant heating cavity 307 where the particles are heated. The cavity 307 is disposed along the flow direction of the air and particulate mixture coming from the mixing unit 610 is generated. The radiant heating cavity 307 contains an opening or a window to the radiation of the radiation generator 400 initiate. In the radiant heating cavity 307 the particles absorb at least part of the radiation and are thereby heated. After leaving the radiant heater cavity 307 promotes the particle flow heating nozzle 371 the heated air / particle mixture to the workpiece 200 where the particles are on the workpiece in one area 155 impinge and deal with the workpiece 200 connect. Again, the radiation source 400 built to provide appropriate radiation for 3D printing. radiation source 400 , Mixing unit 610 and particle flow nozzle 306 are movable, and possibly on a 3D printhead 500 mounted, which is attached to a Cartesian axis configuration or a robot arm.

8b provides an embodiment for heating by irradiation of the surface of the workpiece 200 where again a particle stream is used for the 3D printing process. The embodiment too 8b differs from the embodiment 8a only in that the radiation of the radiation source 400 not in the particle stream heating nozzle 371 is applied, but on the workpiece 200 is directed to heat this. That's why the 3D printing tool includes too 8b a particle flow nozzle 306 which differs from the particle stream heating nozzle 371 this distinguishes that no radiant heating cavity 307 is needed (although still available). The particle flow nozzle 306 is from the mixing unit 610 supplied with the gas and particle mixture and passes the (cold) mixture to the workpiece 200 , The workpiece 200 may or may not be preheated.

Therefore, unlike 8a where the mixture of particles and gas inside the heating nozzle 371 is heated and then as a mixture of air and heated particles to the workpiece 200 is passed on, at 8b where the particles and the gas as a cold mixture the particle flow nozzle 306 leave, then at impact on the workpiece 200 from the radiation source 400 to be heated to allow the workpiece 200 local, as well as the specific particle / air mixture to heat and fuse. For example, the particles may be heated or pre-heated just before this on the intended location on the workpiece 200 crack open. This can be achieved by appropriate alignment of the radiation. In addition, the region on the workpiece can also be preheated.

9a to 9d show further embodiments for using a particle flow to produce a workpiece in the 3D printing process.

9a shows a 3D printing tool, wherein the particle flow consists of a mixture of different particles (for example, different components or materials). The 3D printing tool again includes a compressor 102 to compress the air. The compressor 102 generates a gas stream 617 which of a pipe 616 is directed. A first gas / particle mixing unit 630 is downstream of the compressor 102 attached to the compressed gas with a first material component (eg. Part A) to mix. The particles A are in a particle storage 603 stored and are through a pipe 620 to the first gas / particle mixing unit 630 directed.

In addition, the 3D printing tool contains another particle memory 604 for a second material component (eg particle B). This second particle store 604 is by means of another tube 604 with a second gas / particle mixing unit 640 where the particles B are mixed with the previously generated compressed air / gas mixture. The second gas / particle mixing unit 640 supplies the particle flow heating nozzle 371 with the mixture of compressed air, particles A, and particles B. The particle flow heating nozzle contains a cavity 307 for selectively heating the particles A and / or particles B by radiation emitted by a radiation source 410 is dispensed (as in previous embodiments). After heating the mixture of particles A, particles B and compressed air, the mixture is considered to be in the gas stream 628 to the workpiece 200 directed. The mixture hits the workpiece 200 within a target area 158 where particles A and B join together around the workpiece 200 to shape.

Following this embodiment, it becomes possible to incorporate pigments or other color particles into the workpiece to achieve a particular desired design. For example, the particles A may consist of pigments, whereas the particles B are transparent and / or have a certain rigidity. Different colors can be mixed accordingly. This allows the production of a workpiece with different colors in predetermined regions.

The 3D printing tool as with 9a can be displayed again on a tool head 500 be mounted, which is movable and connected to a Cartesian axis configuration, or a robot arm (for example, on an axis or robot arm) is about to over the surface of the workpiece 200 to be moved.

9b shows a further embodiment for a 3D printing tool, which of the embodiment as in 9a shown, is similar. However, in the embodiment, too 9b not two types of particles mixed together, but particles A, which again in the first particle storage 603 are housed with fibers which in the second particle storage 604 are housed, mixed. The fibers are passed through a tube 625 , which ensures the flow of fibers without clogging, to the second mixing unit 640 directed. After mixing the particles A with the fibers and compressed air, the mixture produced becomes the particle flow heating nozzle 371 passed where the mixture is heated and subsequently to the workpiece 200 as in the previous embodiments too 9a , is directed. The particle stream heating nozzle 371 can restore a cavity 307 contained in which a radiation generated by a radiation source 410 , is judged. The radiation form may again consist of microwave radiation which can heat either the particles A and / or the fibers sufficiently around the workpiece 200 to shape. The incorporated fibers in the workpiece improve the physical properties such as increased resistance or rigidity. By incorporating electrically conductive fibers, certain radiation-absorbing and / or reflective properties can be achieved. It is even possible to mix fibers with sufficient density to locally adjust the electrical resistance, or the conductivity of the workpiece.

In embodiment too 9c The 3D printing tool contains a first particle flow control unit 635 and a second particle flow control unit 645 which controls the amount of particles A and / or B (or fibers). In addition, both particle flow control units 635 . 645 with a control unit 650 be connected. The control unit 650 can be constructed so that the mixing ratio can be controlled so that the resulting mixture 651 consists of a predetermined amount of particles A and a predetermined amount of particles B, which are in a predetermined ratio 625 Particle A and Particle B results.

For example, the ratio of the materials may also be changed gradually during operation, so that the workpiece 200 composed of material compositions which can vary continuously or stepwise or not at all. Again, the particles may have different shapes and may include fibers and / or granules or other forms of particles.

As a result, this embodiment allows the particle mixture to be selected freely in accordance with the requirements or wishes of the user (for example a desired property of the workpiece). For example, certain areas or parts of the workpiece may be formed of different materials, or may have some particular desired properties (eg, stiffness or flexibility), while other areas may not be so designed.

All other components can be identical to the previous embodiments (see, for example. 9a ), so that a repetition of the description can be omitted.

9d shows a further embodiment, wherein the particles are electrically charged, before this to workpiece 200 be directed. The embodiment of 9d is the embodiment as in 8a shown similar, and differs only in that between the particle flow heating nozzle 371 and the air / particle mixing unit 610 a particle ionizer 700 is used. The particle ionizer 700 consists of an ionization cavity 720 with an inflow and an outlet for the mixture 631 the particles and the compressed air. The ionization chamber 720 includes an ionizing wire 710 , which with a high voltage supply 730 which is a voltage for the ionization wire or the ionization grid 710 delivers, so the air / particle mixture 631 from the mixing unit 610 is electrically charged. In the ionization chamber 720 becomes a charged particle stream 740 generated. The charged particle flow 740 is subsequently directed to the particle flow heating nozzle where it passes through the radiation source 400 as previously described (eg by using a cavity 307 inside the nozzle 305 ) is heated. After leaving the nozzle 305 becomes the electrically charged, heated mixture 741 on the workpiece 200 directed. The workpiece 200 can be grounded and contain electrically conductive components around the workpiece 200 to unload.

An advantage of the embodiment as in 9d shown, is that the charged particles from the workpiece 200 be attracted and thereby cloud formation around the particle flow heating nozzle 371 and / or the workpiece 200 can be avoided. This in turn can reduce the material requirements for the 3D printing process.

All other components like the 9 are identical or similar as already by the previous figures (eg. 8th ) and described so that a repetition of the description can be omitted here.

10a shows a further embodiment which similar to the embodiment at 8a is. However, the embodiment includes 10a a control valve 810 to control the particle flow and an actuator 820 for the control valve 810 , The control valve 810 is along the particle flow between the first particle storage 603 and the gas / particle mixing unit 610 appropriate. The actuator 820 for the control valve 810 can be controlled by a control unit (like the control unit in 9c , but not shown in 10a ) and is constructed to be the control valve 810 to control the particle flow rate accordingly. Accordingly, the density of the particles in the compressed air can be changed and the 3D printing tool can provide an adjustable particle flow rate (or density). The particles can return through the radiant heating 410 in the particle stream heating nozzle 371 to be heated (see 9d ).

10b shows further details of the control of the embodiment 10a , In particular, this embodiment includes a particle control device 800 which is the actuator 820 for the control valve 810 , a dosage control 830 , and a counter 840 contains. The counter 840 is designed to measure a density or number of particles in the stream of gas-particle mixture. For example, the counter 840 be configured to receive radiation 850 and the received radiation depends on the number or density of particles passing through the particle / gas mixing unit 610 is introduced. For example, the intensity of the received radiation may vary depending on a change in particle density. The counter 840 is further configured by a corresponding signal (indicative of the number of particles) for dosing control 830 which based on it, the actuator 820 of the control valve 810 controls and thereby determines the density of the particles or the particle rate, which of the mixing unit 610 is supplied. As a result, this embodiment includes a control loop 801 to effectively control the particle density in the gas stream. For example, the dosage control 830 include a comparator which compares the target value with the current count value.

Again, all other components are equivalent or identical as in the previous figures (eg. 8th ), so that a repetition of the description is not necessary.

11a FIG. 12 illustrates another embodiment which is similar to the embodiment as in FIG 8a shown. In addition to the embodiment of 8a contains the embodiment too 11 a temperature controller which is capable of controlling the temperature of the mixture of gas and particles, for example when leaving the particle stream heating nozzle 371 , to eat. The temperature control allows feedback for the control of radiation (eg intensity) from the radiation source 410 is delivered.

In particular, the particle stream heating nozzle includes a radiation window 715 through which thermal radiation 716 , which is emitted from the heated particles in the gas / particle mixture, can be analyzed. For example, the 3D printing tool may be a receiver 705 for thermal radiation 716 contained, which is capable of the emitted heat radiation 716 to receive, which through the radiant window 715 arrives. After receiving the thermal radiation 716 For example, a signal representative of the heat of the particles becomes a meter or temperature control 707 forwarded. The temperature control 707 receives and analyzes the signal from the heat radiation receiver 705 is generated and controls based on the radiant heating 410 around the radiation 440 (for example, by increasing and decreasing the intensity of the microwave radiation). As a result, this embodiment includes a closed loop to effectively control the heating of the particles.

11b shows an embodiment with a combination of different control circuits. In particular, this embodiment combines the control loop as in 10b shown with a control loop as in 11a shown. In addition, a gas flow control 760 used which is configured to the gas flow 617 to analyze which of the compressor 102 is produced. The gas flow control 760 can function as a comparator, which, for example, the gas pressure at the feed to the compressor 102 with the gas pressure at the outlet of the compressor 102 compares. The gas flow control 760 gets on the compressor 102 connected, for example, to change the compression rate of the compressed air to thereby the flow of compressed air 617 to control. Thus, in this embodiment, not only the particle flow rate is controlled as at 10b described, as well as the temperature as with 11a but also the pressure of the gas stream.

Furthermore, the embodiment includes 11b a central control unit 740 , which is constructed in such a way to the corresponding signals of the various control units 707 . 760 . 830 to receive and based feedback signals sends to regulate the temperature, the gas pressure and the dosage of the particles. This allows the temperature control 707 , the gas flow control 760 and the dosage control 830 by means of a central control unit 740 by sending control signals to the individual controllers 707 . 760 and 830 be coordinated.

Again, all other components may be similar or identical to those of, for example 8a so that a repetition of the description can be omitted here.

12a shows a further embodiment. which in addition to the components as in 8a shown, a gas preheating for the pre-heating of the compressed air contains, which from the compressor 602 is produced. The gas preheater 840 is between the compressor 602 and the particle / gas mixing unit 610 positioned and consists of a heating wire 842 , as well as a gas preheating cavity 844 and is with an electric power source 846 connected. The electrical power source 846 supplies the heating wire 842 with electrical energy. The heating wire 842 is in the gas preheating cavity 844 used around the stream of compressed air 617 to heat, which from the compressor 602 is produced. After leaving the gas preheater 840 becomes the heated gas 847 to the particle / gas mixing unit 610 directed, so that in this embodiment, the heated air is mixed with the particles. Heated particles and heated air 848 leave the particle stream heating nozzle 371 ,

Again, all other components are similar or identical to those in the previous figures such as 8a can be displayed so that a repetition of the description can be omitted here.

The embodiment at 12b contains in addition to the components 12a an additional cooling nozzle 860 , as well as a bypass pipe 850 which with the compressor 102 and the cooling nozzle 860 connected is. This allows the cool compressed gas of the compressor 102 , the preheater 840 , as well as the cooling nozzle 860 and after preheating and mixing, the particulate stream heating nozzle may apply the mixture of particles and heated gas to the workpiece 200 hand off. In addition, the cooling nozzle conducts 860 the cool gas on the workpiece 200 , For example, the particle flow heating nozzle 371 and the cooling nozzle 860 be arranged so that the cool compressed air to the workpiece 200 thereby hits the workpiece 200 Cool in the targeted region and cure the 3D printing material after the heated gas / particle mixture has been applied to the workpiece. The timing can be described in terms of the relative direction of movement between the workpiece 200 and the 3D printing tool, as well as the cooling power of the gas stream. In order to increase the effectiveness of the cooling, the temperature of the gas can additionally by a cooling device between the cooling nozzle 860 and the bypass pipe 850 be reduced.

In accordance with embodiment 13a the particle store consists of a pressurized chamber. To implement this, the embodiment includes a gas flow separator 862 which is in a partial pressure switch 860 is housed. The partial pressure switch 860 is between the compressor 602 and the particle / gas mixing unit 610 attached, and so constructed by a part of the compressed air to the particle storage 603 respectively. This increases the pressure within the particle store 603 , and causes the particles in the particle store 603 through the pipe 616 to the gas / particle mixing unit 610 be moved, or be supported. The mixture of gas and particles 619 additionally facilitates the flow through the tubes to the mixing unit, or intermix chamber 610 is reached.

All other components are identical to those of the embodiment to 8th ,

The embodiment too 13b differs from embodiment too 13a by being at the bottom of the particle store 603 , Inlets 618 for compressed air 617 are provided, which around the outlet of the particles of the pressurized particle storage 603 are arranged. This allows the advantage that the particles within the particle store 603 , Can leave this with lower flow resistance. For example, the compressed air which enters the particle storage 603 initiating a buoyancy which increases the pressure on the individual particles by their own weight near the outlet of the particle store 603 reduces and facilitates the flow of particles. In addition, this can prevent particulate settling and hence the particle flow rate through the tube 616 increase.

Again, all other components may be similar or identical to those shown in previous figures, for example 13a and 8a can be represented and described, so that a repetition can be avoided at this point.

14 shows a further embodiment of a 3D printing tool with a microwave particle heating. The 3D printing tool contains a compressor 603 with a rotor, which with a compressor motor 604 connected and the rotor of the compressor 603 drives. The air is forced radially outward where a nozzle is mounted to supply the compressed air to the gas / particle mixing unit downstream.

In addition, the 3D printing tool contains a particle memory 606 which room for the storage of the powder 608 which is used as 3D printing material. The 3D-printing powder 608 becomes the gas / particle mixing unit 630 fed. In addition, a material flow control 708 used, which is the powder amount of the powder 608 controls which of the gas / particle mixing unit 630 is supplied. The material flow control 708 can again by a central control unit as previously described (not at 14 shown). The gas / particle mixing unit 630 is built around the 3D printing powder 608 into the stream of compressed air through a 3D pressure powder outlet 607 which is in the gas / particle mixing unit 630 is housed, and for example within a central position in the gas stream. As a result, the compressed air flows around the 3D pressure powder outlet 607 , which creates a vacuum for the 3D printing powder, which is an efficient mixture of gas and particles within the gas / particle mixing unit 630 allows. The powder outlet 607 can be further adapted to turbulence in the gas / particle mixing unit 630 to reduce. This can be done, for example, by forming a guide element (see upstream of the powder outlet 607 ), which expels the gas around the powder 607 leads to minimize turbulence.

The 3D printing tool off 14 The others contain a microwave emitter 410 , a microwave waveguide 412 , as well as an adapter for the microwave / particle flow 416 with a microwave cavity resonator 414 , The microwave waveguide 412 is so constructed around the microwaves, which from the microwave emitter 410 are delivered to the microwave cavity resonator 414 to lead. The microwave cavity resonator 414 is perpendicular to the flow of the mixture of compressed air and 3D printing powder 608 arranged. The microwave cavity resonator 414 is constructed so as to generate a high-intensity microwave radiation, for example in the form of standing waves, which surround the chamber 414 fill out.

The adapter for the microwave / particle flow 416 with the microwave cavity resonator 414 For example, a gas-tight microwave window 419 included, so the mixture of gas and 3D printing powder 608 through the microwave cavity resonator 414 can flow, but is prevented from transverse to the original flow direction into the microwave cavity resonator 414 to get. In addition, the adapter contains 416 a deflector 418 to prevent the microwave radiation from entering the mixing unit 630 or the particle stream nozzle 316 penetrate, which as a further embodiment as part of the adapter 416 can be designed. The further particle stream nozzle 316 directs and concentrates the flow of heated particles 421 to the workpiece 200 , The 3D printing tool can be movable along at least one axis 315 by using a Cartesian axis configuration, or a robotic arm, or similar configurations (see previous embodiments, e.g. 9 ).

15 FIG. 12 illustrates another embodiment of radiant heating of a particle stream in a 3D printing tool similar to that of FIG 14 shown. However, in this embodiment, laser radiation is used for heating the 3D printing material (instead of microwave radiation as in the embodiment too) 14 ). Therefore, the embodiment includes 15 a laser emitter, which for example in a housing 416 and a laser / particle flow adapter 417 is housed. The laser radiation is for example in a radiation protection 480 passed, which is a laser mirror 470 contains around the laser radiation, which from the laser emitter 415 is delivered to the laser radiation / particle flow adapter 417 to lead. The radiation protection 480 can again be shaped as a tube, which directs the laser radiation through the mirror, which is installed for example in a kink, 670 to the adapter 417 passes.

The laser / particle flow adapter 417 , will be back between the mixing unit 630 (or transfer unit), for the 3D printing material, as well as the particle flow nozzle 316 used, which the heated particle flow to workpiece 200 passes. The adapter 417 contains, for example, a heat transfer chamber 419 which is suitable for introducing the energy of the laser radiation into the particles (for example powders) which are in the air stream of the compressed air coming from the compressor 603 is generated. Again, the adapter contains 417 a window 422 , which is oriented along the direction of flow and permeable to the laser radiation, but against the flow of compressed gas, as well as the particles introduced seals, and a mirror 421 which returns the laser radiation back to the heat exchange chamber 419 reflected.

16 show how the preheated particles and / or fibers connect around the workpiece 200 to shape.

For example, at 16a a combination of particles 920 and fibers 910 heated and moved together. The heated particles 920 be on the surface of the workpiece 930 involved and accumulate on the heated region of the workpiece 940 for example, the width or height of the workpiece 200 to enlarge globally or locally. The embedded particles 190 which are heated or not heated, for example, the strength of the workpiece 200 increase.

16b shows an embodiment wherein only preheated particles on the surface 930 of the workpiece 200 be involved. Again, an accumulation of particles in the area 940 reached, and the width of the workpiece 200 increased by accumulation of heated particles.

16c provides a cooling effect of a Luftromes 950 (or any other gas), for example, which carries heated particles. Once the particles are on the surface of the workpiece 930 the airflow cools the particles after impact in the region 960 so that the following exposure of the heated particles 920 opposite the air flow, the workpiece in the region 200 cools. The workpiece 200 grows through the incorporated particles. As long as the heated particles 920 together with the airflow 950 moving, is only a limited heat exchange between the particles 920 and the airflow 950 possible (since air is a good thermal insulator). However, at the moment in which the particles on the workpiece 200 hit and be bound, the air flow immediately start the still heated particles 920 Cool down, as the relative velocity between air flow 950 and the heated particles abruptly increases, and thus the cooling effect is achieved.

16d shows the heating by a directed radiation 905 , which is directed to the workpiece. In the embodiments where this is applied, the cold or heated particles become 925 at the moment (or shortly before) of their contact with the surface 930 through the directed radiation 905 heated. This allows the advantage that not only the particles are heated, but also the surrounding area 935 of the workpiece 200 , reducing the ability of the heat particles 920 the surface of the workpiece 200 is increased to pierced, and a more homogeneous workpiece 200 can be produced. The accumulation of heated particles 920 becomes the workpiece again 200 grow to thereby form a three-dimensional object.

A wide selection of materials can be used. For example, the particles may be carbon, resin, or any type of synthetic material (organic as well as inorganic), polymers, metals, or non-metals, or minerals, as well as fibers. Even textile or cementous materials can be used.

17a show two possible velocity distributions 810 the particle 920 in air, inside a pipe.

In the embodiment too 17a The tube contains a flat, smooth-shaped tube inner wall 820 leading to the velocity distribution 810 leads. The pipe inner wall 820 slows the air close to the same, resulting in differential velocities between the heated particles moving along the flow direction 925 (eg heated, cold, gas) leads. This will have the particles 925 a maximum speed in the central position of the air flow, as well as a minimum speed near the pipe inner wall 820 , The illustrated velocity distributions generate a dynamic force which is applied to the particles 925 is exerted, which forces this to move to the central position (tube center) where the velocity of the air is maximum, resulting in a focussing effect transverse to the tube direction 940 leads.

This dynamic force is generated by the different velocities within the airflow, which are on opposite sides of the particles 920 Act. It is understood that this dynamic force always acts as long as the velocities of the air flow on the opposite sides of the particles 920 are different and therefore dependent on the size of the particles and the radial velocity gradient (the larger this gradient, the stronger the force). Furthermore, there is also a velocity difference within the air stream, which acts on the opposite sides of the particles, even if the velocity of the particles 920 largely corresponds to the velocity of the air stream (eg at a particular radial position), resulting in the mentioned dynamic force. The resulting force is indicated by the arrows 935 shown. Since this force is oriented radially to the pipe cross-section, there is a focusing of the particles within the air flow.

17b shows a further Auführungsform the pipe wall 920 , In this embodiment, the pipe wall 920 from a non-planar pipe inner wall 830 showing the friction between the airflow and the pipe 820 elevated. Accordingly, the speed of the air near the pipe wall 830 significantly compared to embodiment too 17 reduced, the speed is maintained in the center on. On the other hand, the speed in the center can be further increased to maintain the same rate of compressed air through the pipe, assuming that the compressor can deliver the same amount of air at higher pressure. As a result of the increased velocity differential of the air surrounding the particles, the force becomes the particles 925 In zetrale radial position moves increased, since the speed differences 946 on the opposite sides of the particles compared to larger in embodiment too 17b are as in embodiment too 17a , The resulting increased force on the particles 925 is through the arrows 936 shown. The focusing of the (hot or cold) particles 925 Within the air flow can be adjusted by adjusting the friction of the air flow against the pipe inner wall 820 . 830 of the pipe to be changed.

In the embodiment which is in 18 is shown, an additional rotatable nozzle 326 between particle flow heating nozzle 371 and the workpiece 200 used. The rotatable nozzle 326 is with the particle flow heating nozzle 371 through a flexible tube 309 connected, which is the rotatable nozzle 326 allowed to be rotated while with particles from the particle flow heating nozzle 371 is supplied. In particular, the stoke heating 410 and / or the feed unit 305 together with the rotatable nozzle 326 be rotated. Because the heater can at least to some extent soften or tackify the 3D printing material, joint rotation may allow the advantage of avoiding potential blockage of the heated 3D printing material in the tubes / tubes that provide the 3D printing material can.

This embodiment further shows a gimbal with a nozzle port 358 , which with the rotatable nozzle 326 is connected, and a rotation of the rotatable nozzle 326 allows one or more axes of rotation. This allows alignment of the particle flow from multiple directions onto the workpiece 200 ,

The rotatable nozzle 326 is constructed around the particle flow along a controllable particle flow angle 319 on the workpiece 200 to steer. Therefore, the area 155 in which the particles in the workpiece 200 be integrated by adjusting the controllable particle flow angle 319 configurable. The particle stream heating nozzle 371 , as well as all other components, which in 18 are identical to those which in the previous embodiments (see embodiment to 8a ) being represented.

In other embodiments, the gimbals are gimbals 356 , as well as the rotatable nozzle 326 as applied in previously described embodiments and an additional description of the other components is omitted here. In addition to the cardanic suspension, any other configuration capable of adjusting the particle flow angle continuously or in steps is applicable. For example, a Stewart Platform (Hexapd), etc.

In other embodiments of the present invention, the radiant heater is used to cure one or more adhesive solutions. Furthermore, the radiation can trigger a chemical reaction of the 3D printing material (or components contained) when on the workpiece 200 is encountered. For this purpose, in other embodiments, the radiation is not constant, but varies depending on the desired functions (eg. To cure, trigger a chemical reaction, etc.). For example, the particle stream from the nozzle may cure as a two-component resin (with or without exposure to additional radiation from the radiation source).

19 shows a further embodiment, wherein at least a part of the feed unit 300 and the radiant heating 400 in a 3D printing unit 500 combined, which together with the workpiece 200 and a filter 698 within a housing 111 are constructed. The housing 111 is designed to provide a closed environment for the 3D printing process, so that the 3D printing material 110 , which is not used for printing the workpiece, can be reused. If the 3D printing unit 500 the material 120 to the workpiece 200 possibly can only lead a part 155 for the construction of the workpiece 200 be used. Another share 198 of the 3D printed material can be used together with the transport gas 197 (For example, air or any other gas or liquid) around the workpiece 200 stream. This excess material 198 , as well as the gas 197 , are collected and become a filter 698 which is constructed, the reusable 3D printing material and the transport gas 619 to separate from the excess mixture. The transport gas 619 , as well as the recycled 3D printing material 628 leave the case 111 , The carrier gas 619 gets the compressor 602 fed, and the recycled 3D printed material is the material storage 603 fed. Additionally, the material store becomes 603 new additional 3D printing material 629 from the material store 608 fed. The material storage 603 Holds the material 620 for the 3D printing unit 500 inside the case 111 in front. In addition, the compressor leads 603 compressed gas (any kind of gas or liquid) of the 3D printing unit 500 inside the case 111 to.

The 3D printing unit 500 together with the compressor 602 and the material storage 603 can be of identical construction as already shown in the previous embodiments. The embodiment as in 19 differs from the previous embodiments only by using a housing 111 and devices to recover and recycle the unused material and carrier gas of the 3D printing process. This saves the embodiment 19 3D printed material and increases safety by recycling the unused 3D Printing material and carrier gas. Accordingly, other embodiments also refer to a closed circuit for the 3D printing material and the carrier gas so that no 3D printing material / carrier gas is lost.

20 FIG. 12 shows another embodiment relating to a combination of the 3D printing tools as described in one of the previous embodiments. Specifically, here, a plurality of 3D printing tools are arranged into a series (eg, a line, or any other pattern), each material being supplied with material from a central storage unit, and a carrier gas from a compressor 602 by means of a pipe system 799 , The material storage 603 , as well as the compressor 602 , may be of the same type as those illustrated in any of the previous embodiments. and the material and the carrier gas to the plurality of mixing units 610 deliver. The mixing unit 610 may have the same internal structure as already shown in other embodiments possess. For example, the mixing unit 610 a cavity 307 contain radiation from radiation sources 410 to receive a particle flow control 635 , and is through the pipe system 799 to the compressor 602 connected. In addition, a central control unit 740 the multitude of river controls 635 regulate. All components bearing the same referencing number as in previously described embodiments may be similar or identical to those described above.

As a result, it is possible to have an entire row (for example, the illustrated strips) along the workpiece 200 is designed to print simultaneously, so that the workpiece, or the 3D printing units only have to be moved along one direction around a material layer of the workpiece 200 apply. Accordingly, the workpiece or 3D printing units may be configured to be moved along a vertical direction after application of a layer, and in an efficient and rapid manner to print layer by layer as in FIG 20 shown. It is also possible the mixing units 610 in an entire area (such as pixels of a display), so that only the vertical movement of the 3D printing tools is needed to print the workpiece along this vertical direction.

21 shows a method of 3D printing according to an embodiment of the present invention. The method includes: supplying printing material S110 for 3D printing, whereby the printing material fuses by heating to form the workpiece; And selectively heating S120 the 3D printing material by irradiating the same with radiation sufficient to fuse the 3D printing material while feeding the 3D printing material to the workpiece to be molded.

This process can also be assisted or controlled by a computer control, a person of prior experience can quickly recognize that the various steps of the previously described methods can be controlled by programmed computers. Embodiments are also contemplated which also include program storage devices, such as digital data storage media, which are machine or computer readable, and which may encode machine-executable or computer-executable programs and instructions, the instructions controlling some, or all, of the steps of the previously described methods. when running on a computer or processor. In addition, embodiments are provided that include necessary computer-executable programs that encode geometric information as sequenced instructions, and that can be interpreted and executed by the 3D printing machine, and more specifically the 3D printing tool.

Advantageous aspects of the various embodiments may be summarized as follows.

Embodiments relate to a 3D printing tool wherein heat is transferred not by direct material contact but by radiation. Unlike conventional plastic extrusion dies, there is no heated contact surface to transfer the heat energy to the 3D printing material. The 3D pressure nozzle stays cool. And unlike conventional laser sintering, the 3D printing material is in motion while it is heated and the material is selectively applied. There is no need to strongly preheat large portions or the entire workpiece prior to material attachment. Instead, the material may be heated prior to impact on the workpiece. However, other embodiments may also relate to combinations of these two processes (pre-heating of the workpiece and Radiation Heating of Particle Jet). For example, the workpiece may include a portion that is preheated, and the powder may additionally be preheated before being supplied to the workpiece.

Compared to conventional 3D printing processes, embodiments of the present invention allow for a faster 3D printing process, and the material can be deposited locally differentiated (eg, the composition of the printing material and the workpiece can be changed during printing or manufacturing of the workpiece). Accordingly, the workpiece may consist of a composite, which is characterized by a continuously variable material composition of different materials. Furthermore, processes such as pigmentation and finishing can be better controlled. Artifacts (for example, layer marks) that arise during 3D printing can be reduced because the embodiments allow a constant process control (for example by means of a control loop). As the whole process is more reliable and, for example, the nozzle is a resilient component, and because the 3D printing tool itself is heated less than conventional FDA 3D printing tools, thermal loads are reduced, which in turn increases the robustness of the 3D printing tool. In addition, the exposure to mechanical stress is reduced. Other achievable advantageous properties consist in a higher resolution, as well as functionally staggered materials, with the ability to use the techniques shown in the context of direct industrial 3D printing in goser economic standards.

The present invention also allows a great deal of freedom in the manufacture of the workpiece. For example, flexible or textile materials, but also workpieces with high strength can be printed.

The description of the drawings represents only the principles of the invention. It is therefore to be understood that those of skill in the art will be able to derive numerous combinations based on embodiments of the illustrated principles, which are thereby assigned to the context of the publication although embodiments are not explicitly described or illustrated here.

Furthermore, it should be noted that while each embodiment is by itself a separate example, in other embodiments the defined characteristics may be combined differently. Such combinations are covered by the publication unless it is noted that a particular combination is not intended.

Claims (17)

A 3D printing tool that is built around 3D printing material ( 110 ), which melts by heating and thereby the shaping of a workpiece ( 200 ), with the following components: a feeder unit ( 300 ) for feeding 3D printing material ( 110 ) for 3D printing; and a radiant heater ( 400 ) for the selective heating of the 3D printing material ( 200 ), which is sufficient for the 3D printing material ( 110 ) while the 3D printing material ( 110 ) the workpiece to be formed ( 200 ) by the feed unit ( 300 ) is supplied. The 3D printing tool according to claim 1, the feeding unit ( 300 ) which has an inflow ( 305 ) for the 3D printing material ( 110 ) and an outlet around the 3D printing material ( 110 ) the workpiece ( 200 ), in which a radiant heater ( 400 ) is stored to the 3D printing material ( 110 ) at the outlet of the feed unit ( 300 ), or outside the feeder unit ( 300 ) at a position on the workpiece ( 200 ) or in the vicinity of the workpiece ( 200 ) to heat. The 3D printing tool according to claim 1 or claim 2, wherein the radiant heater is constructed to receive electromagnetic or particle radiation ( 405 ) having a wavelength which is dependent on the corresponding 3D printing material ( 110 ) is given to deliver. The 3D printing tool according to one of the preceding claims, further comprising a filament drive ( 360 ), which is designed to be a 3D printed material ( 110 ) as a filament with one or more components, wherein the filament drive ( 360 ) is constructed so as to control the speed of the filament, so that sufficient heating of at least one component of the filament is ensured. The 3D printing tool according to one of claims 1 to 3, wherein the feeding unit ( 300 ) is configured to use the 3D ( 110 ) in a gas flow, and wherein the feed unit ( 300 ) furthermore a cavity ( 307 ), through which the introduced 3D printing material is passed, and wherein the radiant heating ( 400 ) is constructed around the 3D printing material within the cavity ( 307 ) to heat. The 3D printing tool according to one of the preceding claims, further comprising a material storage ( 603 ) for the 3D printing material ( 110 ), wherein the material storage ( 603 ) is constructed such that the 3D printing material ( 110 ) as a multiplicity of particles or as a filament or as a liquid, the feed unit ( 300 ). A 3D printing tool configured with 3D printing material ( 110 ), which melts under the exposition of heat and thereby the workpiece ( 200 ), wherein the 3D printing tool comprises: A feeder unit ( 300 ) to the 3D printing material ( 110 ) to provide 3D printing; A Mischeinhheit ( 610 ), which is configured, the 3D printing material ( 110 ) with heated gas, the air (gas) being heated sufficiently to allow the 3D printed material ( 110 ) while the 3D printing material ( 110 ) of the feed unit ( 300 ) is supplied to the workpiece to be formed ( 200 ). The 3D printing tool according to claim 6 or claim 7, a mixing unit ( 610 ) which is built around the 3D printing material ( 110 ) as different types of particles or powders or liquid droplets with a controllable mixing ratio with each other, wherein the radiant heating ( 400 ) or the heated air is adjusted so that at least a portion of the mixed particles or powders or liquids is heated in such a way that the 3D printing material after attachment, with the workpiece ( 200 ) merges. The 3D printing tool according to any one of claims 6 to 8, wherein the mixing unit ( 610 ) is constructed around at least one of the following materials ( 110 ): plastics, ceramics, metals, glass, minerals, polymers, or organic or inorganic materials, or a mixture of the same, or droplets of a liquid, resins, adhesives, or water, or any other material suitable to be carried by the heated gas become. The 3D printing tool according to one of claims 6 to 9, wherein the mixing unit ( 610 ) is configured to determine the ratio of the various powders in the 3D printing material ( 110 ) while the feeder unit is feeding the 3D printing material ( 110 ) feeds. The 3D printing tool according to one of the preceding claims, further comprising a gimbal ( 356 ) or any other configuration which controls the rotation of the feeder unit ( 300 ), such as a Stewart Platform (Hexapod) on which the feeder unit (FIG. 300 ), the gimbal ( 356 ) is constructed around the feeder unit ( 300 ) in one or more independent directions, whereby the material ( 110 ) is fed along one or two lateral direction angles, without the entire feed unit ( 300 ) to move longitudinally. The 3D printing tool according to one of the preceding claims, further comprising a control unit ( 740 ), which is designed to control at least one of the following functions: the supply of the feed unit ( 300 ) with compressed air (gas), the heating by the radiant heating ( 400 ), the density of at least one component of the 3D printing material ( 110 ) and thus the composition of the workpiece ( 200 ), the lateral movement of the feed unit ( 300 ). The 3D printing tool according to one of the preceding claims, wherein the feed unit ( 300 ) and the radiant heating ( 400 ) are integrated into a 3D printing tool. The 3D printing tool according to one of the preceding claims, wherein the feed unit ( 300 ) together with the radiant heating ( 400 ) is movable. The 3D printing tool according to one of the preceding claims, wherein the radiation heating ( 400 ) and the feed unit ( 300 ) are tuned to allow simultaneous fusion and post-flow of the material to the workpiece ( 200 ). A filament bundle ( 105 ) for the fusion of the 3D printed material ( 110 ) by a 3D printing tool according to one of claims 1 to 6, comprising: a core ( 109 ; 111 ); and at least one filament ( 106 ) around a core ( 109 ; 111 ), the core ( 109 ; 111 ) or at least one filament ( 106 ) by the radiant heating ( 400 ) are heated. A method for 3D printing comprising: feeding the 3D printing material (S110) for 3D printing, whereby the 3D printing material fuses by heating and thereby the workpiece ( 200 ) is formed; and selectively heating (S120) the 3D printing material by irradiating the 3D printing material with radiation sufficient to fuse the 3D printing material while it is being molded ( 200 ) is supplied.

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