MANUFACTURING

This application claims priority to Slovenian Patent Application NO. P-2018-00274 filed December 19th, 2018.

Field of Invention

Invention according to present disclosure belongs to the field of auxiliary devices for volumetric additive manufacturing (volumetric 3D printing) of objects, more specifically the invention falls into the field of devices and methods for supplying powder materials from the exterior of an volumetric additive manufacturing device into it's interior, more specifically into a printing volume.

Background of the Invention

Devices for volumetric additive manufacturing enable a final object to be build by consecutive fabrication of individual volumetric parts of the final object or in some cases, an entire object can be fabricated at once. Fabrication of individual volumetric parts of the final object, which is enabled by devices for volumetric additive manufacturing, therefore differs from non-volumetric, conventional devices for additive manufacturing whereby an object is build in a layer-by-layer manner. Volumetric additive manufacturing devices fabricate the final object from individual volumetric parts (printing volumes) of the final object or in some cases, entire objects at once.

Volumetric additive manufacturing is in some cases performed in a vacuum or an environment similar to vacuum inside a build chamber of the device (for example additive manufacturing based on melting with sources of particles, usually electrons); in some devices for volumetric additive manufacturing, the pressure can be atmospheric (for example laser or other melting exposed to air or performed in a print head); and, in some devices for volumetric additive manufacturing, the pressure in the build chamber can be higher than atmospheric (for example laser hardening of liquid materials).

Volumetric additive manufacturing therefore differs from conventional 3D printing in a way that it is possible to fabricate, with each individual print step, a specific volumetric part of the final object which is not a flat 2D layer with specific height but a volumetric part of the final object and in some cases the entire volumetric object at once; whereby conventional 3D printing enables the fabrication of an object by fabricating layers with a specific height, such conventional method of 3D printing is therefore based on a layer-by-layer manner whereby each layer of the object corresponds to a specific individual 2D cross section of the final object, said specific individual 2D cross section having a specific height.

Auxiliary devices and methods, of which the purpose is to supply powder material into the final printing place inside a build chamber of a 3D printer, therefore largely differ in conventional 3D printing and volumetric 3D printing. Devices and methods for powder material supply , which are used in conventional 3D printing, therefore cannot be used with newer, particularly volumetric 3D printers.

Supply of powder materials in conventional 3D printers, whereby the object is being fabricated in a layer-by-layer manner, is described in many technical documentations. Because an object in such conventional 3D printing is usually build on a flat support table, powder materials can be easily applied using straight spreaders, rollers or cylinders. Conventional 3D printers consecutively fabricate 2D layers of the final object in a way that each individual 2D layer of the final object is fabricated separately and consecutively and the method of fabrication therefore repeats for each given layer until the final object is completely fabricated. In conventional 3D printers, the powder material application is always executed onto the previous already fabricated flat layer of the object, and is performed in one main direction, usually height. Layers of powder material are therefore consecutively applied and fabricated onto a flat surface from the lowest layer up to the top layer of the object and until the object in fabrication is completed using a conventional 3D printer.

Such straightforward application of powder material using a spreader, a roller or a cylinder onto the printing place is not possible in volumetric 3D printing, because individual volumetric parts of the final object are build which have volumes, do not necessarily include flat surfaces, and are not necessarily supported with a flat support table. In volumetric 3D printing, the application of powder material is additionally desirable from the sides or even from below or from above the already printed object part, such application of powder material is not required in conventional 3D printing.

In volumetric 3D printing, the powder material application is therefore desirable from more directions that in conventional 3D printers; but above all and more importantly, the printing place itself is not a 2D shaped layer having a specific height but a volumetric printing space (volume). Devices for powder material supply used in conventional 3D printers are therefore unusable for the application of powder material in volumetric 3D printing.

In a volumetric 3D printer, it would be desirable to supply the powder material into a specific printing volume from any direction relative to the already printed object part, which is not an operation that powder material supply devices used in conventional 3D printers enable. The Technical Problem

Hereinafter the technical problem will be described. Devices and methods for volumetric 3D printing of objects where the final object is build from powder material gradually in a way of consecutive fabrication of volumetric parts of the final object or the entire object at once, differ from conventional 3D printers in that they enable the fabrication of individual 3D volumetric parts of the final object, whereby conventional 3D printers enable printing of individual consecutive 2D layers of the final object. The described difference between fabrication of volumetric parts of the final objects enabled by volumetric 3D printing devices and fabrication of individual layers of the final object enabled by conventional 3D printers, therefore leads to vastly different methods of 3D printing inside a volumetric and a conventional 3D printer, and with it entirely different capabilities of said devices.

Unlike conventional devices for 3D printing, the devices for volumetric 3D printing enable:

a) printing in multiple directions relative to the already printed object part (devices for conventional 3D printing have only one main printing direction and usually print in height)

b) printing in multiple directions simultaneously relative to the already printed object part (devices for conventional 3D printing enable printing in only one main direction at the same time, usually height)

In volumetric 3D printing, the application of material is therefore needed into a 3D printing volume which can be located for example below the already printed object part, or the powder material needs to be applied from the sides relative to the already printed object part. The described application of powder material from sides or from below the already printed object part is not possible using currently known devices for supply of powder material.

Currently known powder material supply devices enable the supply of powder material into the fabrication area inside a conventional, layer-by-layer 3D printing machine :

a) by mechanical application using a straight spreader, roller or similar; said spreader, roller, or similar spreads the power material onto a flat surface and no electrical force is used;

b) by using electrical force in a way that the powder material is electrically charged and applied onto a flat support surface with the use of electrical force exerted upon the charged powder material.

State of the Art

Patent application US8124192 describes a method for fabrication of 3D objects whereby the final objects is build by printing sequential layers of the desired object and whereby the powder material is transferred through the hole in the powder material container onto a flat support table using electrical force. In this case, a high electrical voltage is generated between the support table and the container with the powder material; due to the electrical pull, the powder material is pulled through the hole in the container containing the powder material onto the support table.

Patent application DEI 12015004226T describes a device for supply of powder material inside a 3D printer where an object is built in a layer-by-layer manner. The device has a supply unit, which is electrically charged using electrical voltage, and an insulation unit covering an array of plurality of electrodes (electrode unit), whereby the insulation unit is configured in a way to attract the material, which has been negatively charged in the supply unit, onto the positively charged surface of the insulation unit and therefore attracts and removes the powder material from the supply unit using a charged state of the electrode unit. The technical solution described in the above-mentioned patent application describes the supply of electrically charged powder material inside a 3D printing device where an object is fabricated by consecutive fabrication of object's layers. The device therefore enables the application of charged powder material inside a 3D printer where an object is fabricated in a layer-by-layer manner.

None of the above mentioned technical solutions solve the problem of powder material supply into a three-dimensional (volumetric) printing volume inside a volumetric 3D printing device. The invention according to present disclosure is a device for powder material supply into the interior of a volumetric 3D printer, in which the final fabrication of an object is performed in a manner of fabrication of consecutive volumetric parts of the final object and in some cases even entire volumetric objects at once. Because the fabrication of the final object is executed in three-dimensional (volumetric) printing volumes and not 2D layers, the powder material needs to be applied from more than one direction relative to the already printed object part or relative to the initial printing volume in the first step of print.

Device according to the invention enables: powder material transfer from outside of the volumetric 3D printing device into the final printing volume inside a build chamber of said device for volumetric 3D printing, electrical charging or polarising the material charge before the material enters into the final printing volume for the purpose of easier manipulation of the powder material using electrical forces, and the final transfer of such charged or polarised powder material into a desired 3D printing volume from any direction relative to the already printed object part or relative to the initial printing volume in the first step of printing, by using multiaxial mechanisations attached to an application chamber. None of the currently known devices and methods enable the application of charged or polarised material into a 3D printing volume from any direction relative to the already printed object part or relative to the initial printing space in the first step of print.

In both above-described examples (patent application US8124192 and patent application

DEI 12015004226T) the powder material is applied onto a flat surface of the support table, meaning that the known powder supply devices used in conventional 3D printers, where objects are build in a layer-by-layer manner, are unusable for the application of powder material inside a build chamber of a volumetric 3D printer, where the application of powder material is desired into a 3D printing volume which could be located below or next to the already printing object part.

Conventional 3D printers which print a layer after layer, print in only one direction and therefore the material application is performed in only said one printing direction; but volumetric 3D printers, which enable fabrication of volumetric parts of the object, can print in any printing direction relative to the already printed object part and also in multiple directions simultaneously. A technical solution would therefore be desired, which would enable the application of powder material from multiple directions relative to the already printing object part and the application of powder material from multiple directions simultaneously relative to the already printed object part.

Solution to the Technical Problem

Invention according to the present disclosure relates to an auxiliary device and method for volumetric 3D printing, which enables the transfer of powder material from the exterior of a volumetric printing device into the interior of said volumetric 3D printing device, more specifically into the volumetric printing volume located inside the build chamber of the volumetric 3D printer where the individual volumetric part of the final object will be fabricated.

Device according to the present disclosure enables the transfer of the powder material into the final volumetric printing volume from any direction relative to the already printed object part and additionally enables electrical charging or polarisation of powder material charges before the powder material enters into the final printing volume, for the purpose of easier manipulation and positioning of the powder material inside the printing volume itself using electrical forces.

The device therefore enables the transport of powder material being previously outside of the volumetric 3D printer and not being electrically charged or polarised, into the interior build chamber of a volumetric 3D printer in an electrically charged state or polarised state from any direction relative to the individual printing volume.

The device comprises at least one inlet chamber, at least one measurement chamber and at least one application chamber. The device furthermore comprises: at least one connecting pipe connecting the inlet chamber with the measurement chamber, at least one connecting pipe connecting the measurement chamber with the application chamber; a pneumatic powder material transfer system for transfer of powder material from the inlet chamber into a build chamber of the volumetric 3D printer; a system for charging or polarisation of the powder material; a measurement system and a control system. Furthermore the device comprises at least one electrifier installed on the pipe connecting the measurement chamber with the application chamber or on the pipe connecting the inlet chamber and the measurement chamber.

In one example embodiment, the electrifier is configured in a way so that inside the pipe, which has a layer of non-conductive material covering the inner surface of the pipe, an electric field is generated which is sufficient to polarise the powder material granules' charge during the transfer from one chamber to the other through said pipe. In a second example embodiment the electrifier is configured in a way so that it supplies an electric charge onto the powder material through the pipe, which is made out of a conducting material, and in this way the electric charge is added to the powder material during the transfer from one chamber to the other chamber.

A user of the printer adds the powder material in the at least one inlet chamber. The inlet chamber is equipped with at least three doors, said doors being: at least one inlet door through which the user adds the powder material to the inlet chamber interior; at least one outlet door through which the powder material passes into the connecting pipe from the inlet chamber through to the measurement chamber; at least one pressure control door for inlet and/or outlet of gases, on top of which a net is placed which has holes big enough to let through the molecules of gases and does not let through the granules of the powder material in use. At least one inlet chamber is additionally equipped with a weight measuring device (a scale) configured to measure the weight of the powder material in the inlet chamber. At least one inlet chamber is additionally equipped with a pressure measuring device (a manometer) configured to measure the pressure in the inlet chamber.

The inlet door on the inlet chamber reaches to the exterior of the volumetric 3D printer and the inlet door's purpose is the supply of the powder material by the user. The user can be a mechanised machine. The outlet door on the inlet chamber leads into the pipe connecting the outlet door on the inlet chamber with an inlet door on the measurement chamber.

The measurement chamber is equipped with at least three doors, said doors being: at least one inlet door through which the powder material is transported into the measurement chamber interior; at least one outlet door through which the powder material passes from the measurement chamber through the connecting pipe into the application chamber; at least one pressure control door used for inlet and/or outlet of gases, on top of which a net is placed which has holes big enough to let through the molecules of gases and holes small enough to stop the granules of the powder material in use from passing through. The at least one measurement chamber is additionally equipped with a weight measuring device (a scale) configured to measure the weight of the powder material in the measurement chamber. The at least one measurement chamber is additionally equipped with a pressure measuring device (a manometer) configured to measure the pressure in the measurement chamber.

The outlet door of the measurement chamber lead into the connecting pipe which connects the outlet door on the measurement chamber with an inlet door on the application chamber.

An electrifier is installed on the connecting pipe between the measurement chamber and the application chamber or in other example embodiments additionally between the inlet chamber and the measurement chamber. The electrifier is used for electrically charging or polarising the powder material charge before the powder material enters into the application chamber or in other example embodiments, before it enters into the measurement chamber; therefore in the connecting pipe during the transfer of powder material from the measurement chamber into the application chamber or in other example embodiments in the connecting pipe during the transfer of powder material from the inlet chamber into the measurement chamber.

The application chamber is equipped with at least three doors, said doors being: at least one inlet door through which the powder material is transported into the application chamber interior; at least one outlet door through which the powder material passes from the application chamber into the build chamber of the volumetric 3D printer interior ; at least one pressure control door for inlet and/or outlet of gases, on top of which a net is placed which has holes big enough to let through the molecules of gases and does not let through the granules of the powder material in use. The at least one application chamber is additionally equipped with a flow measuring device configured to measure the flow of the powder material passing from the application chamber into the printing volume in the build chamber of a volumetric 3D printer in a specific time. The at least one application chamber is additionally equipped with a pressure measuring device (a manometer) configured to measure the pressure inside the build chamber of a volumetric 3D printer.

All of the doors on all of the chambers in the device described so far enable hermetic closure of said chambers and connecting pipes. Inside each of the mentioned chambers (the inlet chamber the measurement chamber, the application chamber) it is possible to create a vacuum environment. Inside each of the mentioned connecting pipes it is also possible to create a vacuum environment.

The pneumatic powder material transport system comprises: all of the before-mentioned pressure control doors on the inlet chamber, the measurement chamber and the application chamber, on top of which nets are installed which have holes for inlet or outlet of gasses; all of the before -mentioned pressure measuring devices (manometers); an equaliser configured to control the synchronised operation of: a) addition and removal of gases from the gas container through the pressure control doors or addition and removal of gases from the inlet chamber, the measurement chamber and the application chamber; b) closing and opening of all of the pressure control doors on the inlet chamber, the measurement chamber and the application chamber, said pressure control doors through which gases are removed from or added to the inlet chamber, the measurement chamber and the application chamber, for the purpose of pneumatic powder material transfer from the inlet chamber through the first connecting pipe into the measurement chamber, from the measurement chamber through the second connecting pipe into the application chamber, and from the application chamber into the build chamber of the printer.

The application chamber is additionally equipped with a multiaxial mechanisation for routing of charged powder material from the application chamber into a predetermined printing volume where the fabrication of a volumetric part of the final object will be performed in a larger build chamber of a volumetric 3D printer. The application chamber can be additionally equipped with at least two electrodes attached to the outlet door on the application chamber, said electrodes can be used for routing the charged or polarised powder material. Each of the at least two electrodes can be additionally equipped with multiaxial mechanisations and is configured in a way to route or position the charged or polarised powder material in the volumetric printing volume.

The measurement chamber can be equipped with multiaxial mechanisations, which enable the measurement chamber to be moved closer to the printing volume before the beginning of 3D printing. Using multiaxial mechanisations, the measurement chamber can therefore be mechanically detached from the inlet chamber and in such a case, the outlet door on the inlet chamber and the inlet door on the measurement chamber remain closer during printing, because the measurement chamber is moved away from the location of the inlet chamber.

The inlet chamber is installed on the edge of the volumetric 3D printing device in which the object is being fabricated, in a way that the inlet door of the inlet chamber reach out of the volumetric 3D printing device, and on the other side, the outlet door of the inlet chamber reach inside of the volumetric 3D printing device.

Additionally hereto other example embodiments of the device are possible comprising more than one inlet chamber, more than one measurement chamber and more than one application chamber.

Additionally hereto other example embodiments of the device are possible whereby two or more application chambers are connected to one common measurement chamber or to a plurality of measurement chambers. Additionally hereto example embodiments of the device are possible comprising two or more inlet chambers into which the user can add two or more different powder materials for the purpose of volumetric 3D printing of one object using two or more powder materials.

The electrifier and the at least two electrodes, which are installed on the outlet door of the application chamber, are configured in a way so that each can individually generate either a negative or a positive electric field or charge, respectively. The at least two electrodes are configured in a way so they can generate an electric field or an electric field trap in which the powder particles can be trapped.

Example embodiments of the device according to the present disclosure are possible comprising more than two electrodes or more than two electrifiers. The electrifier is configured in a way so that in one step it can generate a negative electric field or electric charge, respectively, and in the next step it can generate a positive electric field or electric charge, respectively. Two or more electrodes are configured in a way so that they can generate either positive or negative electric field.

The core of the device according to the invention is therefore above all the electric charging or polarisation of the powder material charge before the powder material enters into the build chamber of the volumetric 3D printing device, and the transfer of such electrically charged or polarised powder material into the final printing volume which can be located on the sides, below or above the already printed object part or the initial printing volume in the first step of print. Using the pneumatic powder material transfer system, the device according to the invention enables pneumatic transport of the powder material from the exterior of the volumetric 3D printing device to the interior of the volumetric 3D printing device, more specifically into the final printing volume where the material will be fabricated into a volumetric part of the final object or in some cases the entire object; additionally the device enables the charging or polarisation of the powder material in use, which enables an easier transfer and positioning of the powder material using electric force in the printing volume located in a larger build chamber of a volumetric 3D printing device for the purpose of fabrication of a specific volumetric part of the final object or in some cases the entire object at once.

Brief Description of the Drawings

Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein

Figure 1 depicts a schematic view of the cross-section of an example embodiment of the device according to the invention and basic assembly parts of the device according to the invention;

Figure 2 depicts an example embodiment of the device according to the invention comprising two or more electrifiers;

Figure 3 depicts an example embodiment of the device according to the present disclosure comprising plurality of inlet chambers;

Detailed Description of the Invention

Various embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the embodiments of the invention may be embodied in many different forms and should not be considered as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.

Based on the Figure 1, a detailed description of assembly parts of the device according to the invention will be given and the method for powder material transfer enabled by the device for the purpose of volumetric 3D printing will be described. In Figure 1 a schematic view of the cross-section of an example embodiment of the device according to the invention is shown, including assembly parts of the device.

The device comprises an inlet chamber 1 for containing a powder material 2 used for fabrication of an object. The inlet chamber 1 partially reaches to the exterior of the primary device for volumetric additive manufacturing of objects or volumetric 3D printer 0 (hereinafter: the printer 0), respectively, and has an inlet door 3 installed in said exterior, enabling a user of the printer 0 to add the powder material 2 to the inlet chamber 1. An outlet door 4 is installed on the other side of the inlet chamber 1 and is reaching inside of the printer 0, said outlet door 4 is closed during addition of the powder material 2 to the inlet chamber 1 and is open during the transfer of powder material 2 from the inlet chamber 1 through a connecting pipe, which is a pipe 7, into a measurement chamber 5.

The inlet chamber 1 is additionally equipped with a weight measuring device or a scale 13, respectively, a pressure measuring device or a manometer 12, respectively, and a pressure control door 10 used for controlling the pressure. A net is installed on top of the pressure control door 10, said net which has holes big enough to let through the molecules of air, other gasses or fluids in use, and at the same time, the holes on the net are small enough to stop the granules of the powder material 2 from passing through.

The outlet door 4 on the inlet chamber 1 lead into the pipe 7 connecting the outlet door 4 on the inlet chamber 1 with an inlet door 11 on the measurement chamber 5. The measurement chamber is equipped with the inlet door 11 through which the powder material 2 passes from the pipe 7 into the measurement chamber 5.

In this example embodiment of the device according to the present disclosure, an electrifier 6 is installed around the pipe 7 which connects the inlet chamber 1 and the measurement chamber 5 from the outlet door 4 to the inlet door 11.

The electrifier 6 is an assembly part of the device according to the invention and it enables charging or polarisation of the powder material 2 granules' electric charge. In this example embodiment, the electrifier 6 is shaped as a ring and is attached to the outer surface of the pipe 7 in which the powder material 2 passes through from the inlet chamber 1 to the measurement chamber 5. The ring shaped electrifier 6 is made out of conductive material and is connected electrically to an electric unit 8 which supplies electric current to the electrifier 6 and therefore generates an electric field inside the pipe 7, said electric field enables the polarisation of the powdered material 2 charge during the transfer of powder material 2 through the pipe 7 from the inlet chamber 1 to the measurement chamber 5 in one example embodiment of the device. In such an example embodiment of the device, the interior surface of the pipe 7 is coated with a layer of non-conductive material and the electric field aggregates a certain charge (positive or negative) on the surface of the powder material granules. In the second example embodiment of the device, the pipe 7 or a part of the pipe 7 can be made out of conductive material and in such an example embodiment the electrifier 6 using electric unit 8 adds additional electric charge to the powder material 2 during the transfer from the inlet chamber 1 to the measurement chamber 5 through the pipe 7 and therefore causes the powder material 2 to be charged.

In one example embodiment, the supplied voltage generated in the electric unit 8 and supplied to the electrifier 6 is sufficient to polarise all of the powder material 2 charge or a majority of the powder material 2 charge during the transfer of powder material 2 through the pipe 7 from the inlet chamber 1 through the outlet door 4 into the measurement chamber 5 through the inlet door 11 . In other example embodiment, the supplied current generated in the electric unit 8 and supplied to the electrifier 6, is sufficient to charge all of the powder material 2 or a majority of the powder material 2 during transport through the pipe 7 from the inlet chamber 1 through the outlet door 4 into the measurement chamber 5 through the inlet door 11 .

Similarly to the inlet chamber 1, the measurement chamber 5 is equipped with a weight measurement device or a scale 21, respectively, a pressure measurement device or a manometer 26, respectively, an inlet door 11, an outlet door 12, and a pressure control door 29 over which a net is attached with holes big enough to let through the molecules of air or other gasses in use or liquids, and at the same time holes small enough to stop the granules of the powder material 2 in use from passing through.

The measurement chamber 5 can additionally be equipped with a heater 23 which can be used for heating the charged material 2.

A pipe 17 connects the outlet door 12 on the measurement chamber 5 to an inlet door 16 on an application chamber 15. The pipe 17 can additionally be equipped with electrifiers 77 as depicted in Figure 2, in the case that the powder material 2 discharges due to the heating with the heater 23 or in the case of other possible example embodiments of the device in which the first connecting pipe 7 is not equipped with the electrifier 6. The measurement chamber 5 can be detached from the pipe 7 which attaches it to the inlet chamber 1. The measurement chamber 5 can be equipped with multiaxial mechanisation 22 or guides 24, the purpose of which it is to move the measurement chamber 5 closer to the printing volume in the build chamber 100 of the printer 0. Systems for volumetric 3D printing are possible whereby multiple printing volumes or even a plurality of printing devices are placed in one printer 0.

The measurement chamber 5 is connected by the pipe 17 with the application chamber 15 through outlet door 12 on the measurement chamber 5 and the inlet door 16 on the application chamber 15. Similarly to the inlet chamber 1, the application chamber 15 is equipped with its inlet and outlet doors, said doors being the inlet door 16 and an outlet door 25. The application chamber 15 can additionally be equipped with at least two electrodes 19 which are installed on the exterior part of the outlet door 25.

In this example embodiment, a manometer 32 is installed on the outer side of the application chamber 15. Other example embodiments of the device are possible where the manometer 32 is placed elsewhere than on the application chamber 15 but still inside the build chamber 100 of the printer 0. The manometer 32 is configured in a way to measure pressure in the build chamber 100 of the printer 0. The manometer 12 is installed in the inlet chamber 1 and is configured in a way to measure pressure in the inlet chamber 1. The manometer 26 is installed in the measurement chamber 5 and and is configured in a way to measure pressure of said measurement chamber 5.

A pressure control door 20 is installed in the build chamber 100 of the printer 0. Over the pressure control door 20 a net is attached with holes big enough to let through the molecules of air or other gasses in use or liquids, and at the same time the holes on the net are small enough to stop the granules of the powder material 2 in use from passing through.

The pressure control door 10 on the inlet chamber 1, the pressure control door 29 on the measurement chamber 5, the pressure control door 20 in the build chamber 100 of the printer 0, the manometer 12, the manometer 26, and the manometer 32 are all connected to an equaliser 9. For the purpose of pneumatic transfer of the powder material 2 from the exterior to the inside of the printer 0, the equaliser 9 controls the synchronised operation of the pressure control door 10, the pressure control door 29 , the pressure control door 20, the manometer 12, the manometer 26, and the manometer 32. The equaliser 9 mechanically and digitally regulates a pressure pi in the inlet chamber, a pressure p ₂ in the measurement chamber 5 and a pressure p ₃ in the build chamber 100 or outside of the application chamber 15, respectively. The pressure p ₃ can be similar to vacuum environment in some example embodiments, in other example embodiments the pressure p ₃ can contain gasses such as argon or hydrogen. Mentioned gasses can help with discharging of the already printed object part in an example embodiment of the device where the invention according to the present disclosure is used as an auxiliary device to the primary volumetric 3D printer which operates by melting material with irradiation by electron beams (EBM) or other particles with mass and in which the excess charges can aggregate in the already printed object part.

The pressure p ₃ can be similar to the pressure in a liquid, because example embodiments of the device are possible where the device according to the invention is used for the transport of the powder material 2 in the primary volumetric 3D printing device in which melting or hardening of material is performed in liquids.

Furthermore it is possible that the inlet chamber 1, the measurement chamber 5 and the application chamber 15 are shaped in any other way than depicted in Figure 1, for example in a shape of a quad, oval shape, spherical shape or any other shape suitable for containing and transfer of the powder material 2.

Hereinafter the method of operation of the device according to the present disclosure will be described.

Before the powder material 2 is transported to the interior of the build chamber 100 of the printer 0, all of the inlet doors and the outlet doors of the device according to the invention are closed, except for the inlet door 3 on the inlet chamber 1 which enable the user to fill the inlet chamber 1 with the powder material 2. The inlet door 3 on the inlet chamber 1 hermetically close after the user added the powder material 2 to the inlet chamber 1. Weight measurement is made with the scale 13, the manometer 12 measures the pressure p ₃ , the manometer 26 measures the pressure p _2, and the manometer 32 measures the pressure p ₃ .

In the next step, the equaliser 9 controls the appropriate and sufficient production of lower or higher pressure in all of the chambers and pipes in a way so that the powder material 2 is pneumatically transported from the beginning in the inlet chamber 1 through pipe 7 into the measurement chamber 5, and in the next step from the measurement chamber 5 through the application chamber 15 into the build chamber 100 of the printer 0. When the powder material 2 is in the inlet chamber 1, the inlet door 3 hermetically close and therefore enable airtight closure (hermetical sealing) of the inlet chamber 1 in which the powder material 2 is placed. Before the transfer of the powder material 2 from the inlet chamber 1 to the measurement chamber 5, in the measurement chamber 5 the pressure p ₂ is generated, which is lower than the pressure pi in the inlet chamber 1. The equaliser 9 therefore assures that the pressure p ₂ is lower than pressure pi in a manner of removal of sufficient amount of gas from the measurement chamber 5 and as a result, the pressure p ₂ in the measurement chamber 5 is lower than the pressure pi in the inlet chamber 1. Electric unit 8 supplying the electrical current is switched on, and then the outlet door 4 on the inlet chamber 1 and the inlet door 11 on the measurement chamber 5 are opened. When the outlet door 4 on the inlet chamber 1 and the inlet door 11 on the measurement chamber 5 are opened, the powder material 2 flows through the pipe 7 from the inlet chamber 1 into the measurement chamber 5 due to the lower (under-pressure) pressure p ₂ . The electric unit 8 supplies voltage to the electrifier 6 during the transfer of the powder material 2 through the pipe 7 and in this way it charges or polarises the powder material 2 granules during the transfer of the powder material 2 from the inlet chamber 1 into the measurement chamber 5.

In other example embodiments of the device according to the invention, it is possible that the equaliser 9 generates an overpressure (higher pressure) pi in the hermetically closed inlet chamber 1, said overpressure pi being higher than the pressure p ₂ in the measurement chamber 5; and therefore in such an example embodiment, the equaliser 9 enables the pneumatic transfer of powder material 2 from the inlet chamber 1 to the measurement chamber 5 in a similar way. In such an example embodiment the equaliser 9 adds gases through the pressure control door 10 into the inlet chamber 1, and in this way causes the pressure pi to be higher that the pressure p ₂ .

When lower pressure p ₂ in the measurement chamber 5 is established by the equaliser 9, then the outlet door 4 and the inlet door 11 open in the next step and the powder material 2 is transported to the measurement chamber 5. In the next step, the outlet door 4 on the inlet chamber 1 and the inlet door 11 on the measurement chamber 5 close. The process of generating a lower pressure p ₂ in the measurement chamber 5 can be repeated until all of the powder material 2 in use is transferred from the inlet chamber 1 to the measurement chamber 5 through pipe 7. Using the scale 13 and the scale 21 in the inlet chamber 1 and the measurement chamber 5, the weight of the powder material 2 is measured every time the powder material 2 is transported from the inlet chamber 1 to the

measurement chamber 5. In the next step therefore, charged or polarised powder material 2 is located in the measurement chamber 5 wherein the heating of the powder material 2 with a heater 23 can be performed if necessary.

In this step and if necessary, the measurement chamber 5 can be detached from the inlet chamber 1 and moved using multiaxial mechanisation 22 or guides 24 closer to the printing volume or in the case that in the build chamber of the printer, multiple printing devices are placed, closer to the specific device with which the powder material 2 will be used for fabrication of a specific object.

In the next step, the equaliser 9 measures the pressure p ₃ in the build chamber 100 of the printer 0, the pressure p ₂ in the measurement chamber 5, and if needed, the pressure pi in the inlet chamber 1.

Based on the pressure measurements of pressure p ₃ , pressure p ₂ and pressure p ₃ , the equaliser 9 generates a higher pressure p ₂ in the measurement chamber 5 than the pressure p ₃ in the build chamber 100 of the printer 0.

In the case that the measured pressure p ₃ is lower than the pressure p ₂ , firstly, leftover of atmospheric gases can be removed from the measurement chamber 5 and other gases can be added through the pressure control door 29 to the measurement chamber 5, for example inert gases. In other example embodiments of the device according to the invention, whereat in this step the pressure p ₃ in the build chamber 100 is higher than the pressure p ₂ in the measurement chamber 5, which can happen in example embodiments of the device whereby liquid is used in the build chamber 100 of the printer 0, the equaliser assures the production of a sufficiently higher pressure p ₂ in the measurement chamber 5 relative to the pressure p ₃ in the build chamber 100, so that after the outlet door 12 on the

measurement chamber 5 and the outlet door 25 on the application chamber 15 are opened, the measured powder material 2 is transferred from the measurement chamber 5 through the application chamber 15 into the build chamber 100 of the printer 0. In this step, therefore, the pneumatic powder material 2 transfer is performed with the production of lower pressure p ₃ relative the pressure p ₂ or a higher pressure p ₂ relative to the pressure p ₃ .

In the example embodiment of the device as depicted in Figure 2, in this step and if necessary, additional electrifier 77 can be switched on, which is installed on the pipe 17 connecting the measurement chamber 5 with the application chamber 15. The electrifier 77 is supplied with voltage from an electric unit 78, which is attached to the measurement chamber 5 and can therefore move closer to the printing volume together with the measurement chamber 5 using multiaxial mechanisation 22 or guides 24.

When the measurement chamber 5 is close to the printing volume and the pressure p ₂ in the measurement chamber 5 is higher than the pressure p ₃ in the build chamber 100, the final transfer of the powder material 2 through the application chamber 15 into the build chamber 100 of the printer 0 begins. In example embodiments of the device whereby gas is used in the build chamber 100 of the printer 0, a lower/under-pressure p ₃ in the build chamber 100 can be generated by removing gases through the pressure control door 20 installed in the build chamber 100 and connected to the equaliser 9.

The application chamber 15 is equipped with the inlet door 16 and the outlet door 25. At least two electrodes 19 can be installed on the outlet door 25, said at least two electrodes 19 being used for routing or positioning the charged or polarised powder material 2 in the build chamber 100 of the printer 0, more specifically in the volumetric printing volume where the printer will fabricate a volumetric part of the final object or the entire object at once.

Each of the at least two electrodes 19 can be equipped with multiaxial mechanisations and the purpose of said multiaxial mechanisations is to point the electrodes in the desired spatial direction and in this way the manipulation of the charged or polarised powder material 2 can be performed.

Other example embodiments of the device are possible whereby the device comprises two or more application chambers 15 which are spatially placed at different locations and at the same time are all connected to one common measurement chamber 5.

Other example embodiments of the device are possible whereby the device comprises more than two measurement chambers 5. In such other example embodiments one measurement chamber 5 can have two or more outlet doors 12, each of which individually lead to a separate connecting pipe 17, the example embodiments of the device therefore can also include two or more connecting pipes 17 on the end of each an individual application chamber 15 is attached.

Two or more application chambers 15 can be attached each to their own multiaxial mechanisation 115 (Figure 2.) The multiaxial mechanisation 115 enables the positioning of the application chamber 15 closer to the printing volume and enables the application chambers 15 to move together with the melting irradiators, whilst the measurement chamber 5 can be used for the transfer of powder material 2 from outside of the printer into the application chamber in the build chamber of the printer. Figure 2 depicts an example embodiment of the device according to the invention which comprises more than two electrifiers 77 , which are installed on the pipe 17 between the measurement chamber 5 and application chamber 15 in this example embodiment.

Additionally, example embodiments of the device according to the invention are possible, whereby more than two electrifiers 77 can be installed also on the pipe 7 between the inlet chamber 1 and the measurement chamber 5.

Figure 3. depicts an example embodiment of the device according to the invention comprising two inlet chambers, said chambers being the inlet chamber 1 and the inlet chamber Al .

Device according to the invention can have more than one inlet chamber, as shown by the inlet chamber 1 and the inlet chamber Al in Figure 2. The inlet chamber 1 and the inlet chamber Al can be used for the supply of more than one different powder materials, such as powder material 2 and powder material 2A, into the build chamber 100 of the printer 0. The inlet chamber 1 is attached to the measurement chamber 5 and the inlet chamber Al is attached to the measurement chamber A5.

Example embodiments of the device and method according to the invention are possible whereby two different powder materials from two different inlet chambers, such as the inlet chamber 1 and the inlet chamber Al, are supplied into one common measurement chamber, such as the measurement chamber 5.

Example embodiments of the device according to the invention are possible whereby the device comprises more than two inlet chambers 1 and/or more than two measurement chambers 5 and/or more than two application chambers 15.

Example embodiments of the device according to the invention are possible whereby the device comprises more than two application chambers 15 which are all attached to one common

measurement chamber 5.

Example embodiments of the device according to the invention are possible whereby the device comprises more than two measurement chambers 5 all of which attached to one common inlet chamber 1. Example embodiments of the device according to the invention are possible whereby the device comprises more than two electrodes 19 attached to the outlet door 25 or more than two electrifiers, such as electrifiers 6 and 77, installed on any of the connecting pipes, such as pipe 7 and pipe 17.

Each electrifier 6 can be configured in a way so that in one step a negative electric field or charge, respectively, is generated; and in the next step, a positive electric field or charge, respectively, is generated. Electrodes 19 can be configured in a way to generate either positive or negative electric field or charge, respectively. In such a manner, the transfer of the powder material 2 into the build chamber 100 can be executed alternately with oppositely charged or polarised powder material 2, meaning that in one step we can supply a positively charged powder material 2 into the build chamber 100 of the printer 0 and in the next step, negatively charged powder material 2 is transferred into the build chamber 100 of the printer 0.

A system for charging or polarising the powder material comprises the electrifier 6, the electrifier 77, the electric unit 8 and the electric unit 78. All of the assembly parts of the system for charging or polarising the powder material are connected to a control system.

A system for pneumatic powder material transfer from the inlet chamber into the interior of the build chamber 100 comprises assembly parts which specifically enable said powder material transfer, said assembly parts therefore being: the equaliser 9, the pressure control door 10, the pressure control door 29, the pressure control door 20 and all of the connecting pipes from said equaliser 9 to said doors 10, 29, 20, said connecting pipes, which are not depicted on the Figures with additional marks. The equaliser 9 additionally comprises at least one gas container containing gas, from which or to which the equaliser 9 adds or removes gases. The equaliser 9 can additionally comprise containers for containment of other gases or liquids in use.

A measurement system comprises the scale 13 and the scale 21 both of which are individually connected to the control system.

A control system of the device is a central computer part of the device which regulates and controls the operation of all assembly parts of the device according to the invention. The control system includes at least one processing unit for the processing of any current commands of the device; at least one memory unit for digital storage of the commands and other information necessary to operate the device; and other assembly parts which are necessary for the operation of the device according to the invention. The control system is basically a computer connected to all of the assembly parts of the device and has a data input/output channel for each assembly part of the device. The control system gets feedback information on operation of the assembly parts of the device through the data input channels and sends commands/control signals for operation of the assembly parts of the device through the data output channels on the processor. Additionally the device can be equipped with a visual surveillance system for surveillance of the assembly parts of the device.

The control system is connected to the control unit of the primary printer 0 and in this way it coordinates the operation of all of the assembly parts of the device according to the invention with the printer 0, for the purpose of volumetric fabrication of the 3D object.