Three-dimensional printer, three-dimensional printing method, and program

Abstract

One embodiment of the present invention is a three-dimensional printer that executes three-dimensional printing, the three-dimensional printer including: a heating element for applying heat to a filament; an electrode pair for applying voltage to the filament which is heated by the heating element and is in a molten state; and a control unit for controlling the voltage application by the electrode pair. The filament is a thermoplastic substance including electroconductive water and a coagulant.

Description

3D printer, 3D printing method and program

[0001] The present invention relates to a three-dimensional printer, a three-dimensional printing method, and a program.

[0002] With the spread of 3D printers, there has been active research into creating objects using 3D printing.

[0003] Mohammadreza Nofar, Julia Utz, Nico Geis, Volker Altstaedt, and Holger Ruckdaeschel: Foam 3D Printing of Thermoplastics: A Symbiosis of Additive Manufacturing and Foaming Technology. https: / / onlinelibrary.wiley.com / doi / epdf / 10.1002 / advs.202105701

[0004] In 3D printing, a material called a filament is melted with heat and ejected onto the target. The ejected filament solidifies as its temperature drops. Therefore, by repeating this process, a three-dimensional object with a layered structure is formed.

[0005] In such three-dimensional printing, by using a filament containing a foaming agent, it is possible to form a three-dimensional object such as a sponge having bubbles inside.

[0006] However, the foaming of the foaming agent in the filament containing such a foaming agent has been induced by heating. As is well known, it is difficult to control the temperature rise and cooling of heat. More specifically, it is difficult to change the heat locally over time.

[0007] Therefore, when a three-dimensional object having air bubbles inside is formed by three-dimensional printing, the accuracy of the formation is not always high.

[0008] In view of the above circumstances, an object of the present invention is to provide a technique for improving the accuracy of forming a three-dimensional object having bubbles therein.

[0009] One aspect of the present invention is a three-dimensional printer that performs three-dimensional printing, comprising: a heating element that applies heat to a filament; an electrode pair that passes current through the filament in a melted state after heating by the heating element; and a control unit that controls the current flow through the electrode pair, wherein the filament is a thermoplastic material that contains conductive water and a coagulant.

[0010] One aspect of the present invention is a three-dimensional printing method performed by a three-dimensional printer that performs three-dimensional printing, the three-dimensional printer comprising: a heating element that applies heat to a filament; an electrode pair that passes current through the filament in a molten state after heating by the heating element; and a control unit that controls the current passing through the electrode pair, the filament being a thermoplastic material containing conductive water and a coagulant, the three-dimensional printing method including a control step in which the control unit controls the current passing through the electrode pair.

[0011] One aspect of the present invention is a program for causing a computer to function as the above-described three-dimensional printer.

[0012] The present invention allows for improved accuracy in forming three-dimensional objects with bubbles therein.

[0013] FIG. 1 is an explanatory diagram illustrating a three-dimensional printing system according to an embodiment. FIG. 2 is a diagram showing an example of a current supply circuit according to an embodiment. FIG. 3 is a diagram showing an example of control of switch states according to an embodiment. FIG. 4 is a diagram showing an example of the hardware configuration of a three-dimensional printer according to an embodiment. FIG. 5 is a diagram showing an example of the hardware configuration of a data generation device according to an embodiment. A flowchart showing an example of the flow of processing executed by a three-dimensional printer according to an embodiment. FIG. 6 is a diagram showing an example of experimental results according to an embodiment.

[0014] 1 is an explanatory diagram illustrating a three-dimensional printing system 100 according to an embodiment. The three-dimensional printing system 100 includes a three-dimensional printer 1 and a data generating device 2.

[0015] <3D Printer 1> The 3D printer 1 is equipped with a printer control unit 11 and performs 3D printing. The printer control unit 11 is equipped with a processor 91, such as a CPU (Central Processing Unit), GPU (Graphics Processing Unit), or NPU (Neural Network Processing Unit), and memory 92, which are connected via a bus, and executes a program. The printer control unit 11 executes the program to perform, for example, 3D printing.

[0016] More specifically, the printer control unit 11 executes a program to perform 3D printing using, for example, print data. The print data is information indicating the order in which 3D printing is performed (hereinafter referred to as "pass numbers"), which is the order assigned to each area of ​​the object to be modeled, which is divided into multiple areas, and the configuration of each area.

[0017] Therefore, the print data is, for example, information indicating the pass number and whether each area contains air bubbles. Here, the information indicating whether each area contains air bubbles is an example of the information indicating the configuration of each area, as described above.

[0018] The information indicating the configuration of each region is not limited to whether or not it contains bubbles, but may also indicate the amount of bubbles per unit volume in each region. The information indicating the configuration of each region does not necessarily have to be information about bubbles. For example, the information may indicate the filament extraction rate.

[0019] The three-dimensional printer 1 performs three-dimensional printing based on the information indicating the configuration of each region to realize that configuration. For example, when printing a region indicated as containing air bubbles by the information indicating the configuration of each region, the three-dimensional printer 1 applies electricity as described below. In this way, the information indicating the configuration of each region also indicates the processing to be performed by the three-dimensional printer 1 when printing each region.

[0020] The plurality of regions are, for example, regions separated by meshes indicated by 3D mesh data of a 3D model representing the object to be formed. Therefore, the process of dividing the object into a plurality of regions is, for example, a process of separating the 3D model representing the object to be formed by meshes.

[0021] In this way, when three-dimensional printing is performed using print data, each region is modeled in order according to the pass number, so as to realize the configuration of each region. In this way, the object to be modeled is modeled.

[0022] <About the Filament> The filament used by the 3D printer 1 for modeling is a thermoplastic material containing conductive water and a coagulant. Such a filament may be, for example, a mixture of an edible substance containing conductive water and a substance containing an edible coagulant. In such a case, the filament is edible. Therefore, if such a filament is used, an edible object can be produced by the 3D printer 1.

[0023] The edible solidifying agent is, for example, gelatin. Other edible solidifying agents that can be used include, for example, sugar, agar, carrageenan, and a mixture of xanthan gum and locust bean gum.

[0024] The conductive water-containing edible substance may be, for example, juice such as orange juice, etc. The conductive water-containing edible substance may be, for example, an aqueous solution of sodium sulfate.

[0025] Thus, the edible filament may be a mixture of juice, such as orange juice, gelatin, sugar, and aqueous sodium sulfate solution, with the ratio of juice to gelatin to sugar to aqueous sodium sulfate being, for example, 5:1:1:0.2.

[0026] When a filament containing juice, gelatin, sugar, and an aqueous sodium sulfate solution is used, the object that is modeled by the three-dimensional printer 1 is a gummy candy, which is a type of confectionery.

[0027] The print data used by the three-dimensional printer 1 when performing three-dimensional printing is generated, for example, by the data generating device 2. However, the print data used by the three-dimensional printer 1 when performing three-dimensional printing does not necessarily have to be generated by the data generating device 2. For example, the print data may be print data that has been stored in the three-dimensional printer 1 in advance.

[0028] <Data Generation Device 2> The data generation device 2 includes a data generation control unit 21. The data generation control unit 21 includes a processor 93, such as a CPU, GPU, or NPU, and a memory 94, which are connected via a bus, and executes a program. The data generation control unit 21 executes the program to generate print data, for example, in accordance with user input. An example of generating print data in accordance with user input will be described later.

[0029] <More Details of the 3D Printer 1 > In addition to the printer control unit 11, the 3D printer 1 further comprises at least an extruder 101, a nozzle 102, and a movement controller 103.

[0030] The extruder 101 is a so-called extruder in a three-dimensional printer. Therefore, the extruder 101 is equipped with a heating element 104, and applies heat to a filament before sending the filament to the nozzle 102. The sending of the filament to the nozzle 102 by the extruder 101 is controlled by, for example, the printer control unit 11. The heating element 104 applies heat to the filament. The heat generation by the heating element 104 is controlled by, for example, the printer control unit 11.

[0031] The nozzle 102 discharges a filament in a melted state by heating with a heating element 104. The inner diameter of the nozzle 102 outlet is, for example, 1.6 mm. The nozzle 102 is equipped with an electrode pair 105 consisting of a cathode and an anode. The electrode pair 105 is connected to an energization circuit 106, which is a circuit that applies a voltage to the anode and cathode.

[0032] A voltage is applied to the electrode pair 105 by the energization circuit 106, thereby energizing the filament passing through the nozzle 102. The filament passing through the nozzle 102 is in a melted state due to heating by the heating element 104. Therefore, the electrode pair 105 energizes the filament in a melted state after being heated by the heating element 104.

[0033] 1 is a conductor connected to one of the anode or cathode of the electrode pair 105, and conductor L2 is a conductor connected to the other of the anode or cathode of the electrode pair 105. Therefore, for example, if conductor L1 is a conductor connected to the anode of the electrode pair 105, conductor L2 is a conductor connected to the cathode of the electrode pair 105. For example, if conductor L1 is a conductor connected to the cathode of the electrode pair 105, conductor L2 is a conductor connected to the anode of the electrode pair 105.

[0034] The anode is made of, for example, platinum, and the cathode is made of, for example, tin-plated copper. The distance between the anode and the cathode is, for example, 4 mm.

[0035] The movement controller 103 may be any device that can move the extruder 101 in a predetermined dimension out of one, two, or three dimensions. Therefore, the movement controller 103 is a device that can move the extruder 101 in three orthogonal axial directions, that is, the X-axis direction, the Y-axis direction, and the Z-axis direction, using, for example, an actuator, a ball screw, or the like.

[0036] The movement controller 103 may be, for example, a device capable of moving the extruder 101 in two orthogonal axial directions, the X-axis direction and the Z-axis direction, using an actuator, a ball screw, etc. The movement controller 103 may be, for example, a linear stage capable of moving the extruder 101 in three orthogonal axial directions, the X-axis direction, the Y-axis direction, and the Z-axis direction. The movement controller 103 may be, for example, a linear stage capable of moving the extruder 101 in two orthogonal axial directions, the X-axis direction and the Z-axis direction.

[0037] 1 indicates an example of the movement direction of the extruder 101. Note that the object 9 in FIG. 1 is an example of an object being modeled by the three-dimensional printer 1.

[0038] In three-dimensional printing, the printer control unit 11 controls, for example, the amount of filament extruded per unit time from the nozzle 102, the energization of the electrode pair 105, and the movement controller 103. Since the movement controller 103 is a device that moves the extruder 101, the control of the movement controller 103 is the control of the movement of the extruder 101.

[0039] The amount of filament discharged per unit time from the nozzle 102 is controlled based on print data. The amount of filament discharged per unit time from the nozzle 102 is controlled so that a printing target represented by a three-dimensional model indicated by the print data is printed.

[0040] <Technical Significance of Electrical Conduction Through Electrode Pairs and Significance of Coagulant> Here, we will explain the technical significance of electrical conduction through electrode pair 105 executed by 3D printer 1. As mentioned above, the filament used for 3D printing by 3D printer 1 is a thermoplastic material containing conductive water and a coagulant. In fact, because this filament contains conductive water (i.e., water that is not pure water), electrolysis of water occurs inside or on the surface when electrical conduction occurs.

[0041] When water is electrolyzed, hydrogen and oxygen are produced. In other words, bubbles are generated inside or on the surface of the filament. Therefore, an object made using such a filament has bubbles inside. This is the technical significance of applying electricity through the electrode pair 105.

[0042] Furthermore, compared to bubble generation by heating, bubble generation by current application allows for more precise temporal control. This is because current application controls electrons, while heating controls the distribution of phonons. Therefore, compared to bubble generation by heating, current application allows for more precise modeling of three-dimensional objects with bubbles inside.

[0043] The reason why the filament contains a coagulant in addition to conductive water will now be explained. As described above, the filament used for modeling by the 3D printer 1 is a thermoplastic material. Because the filament is a thermoplastic material, the filament is maintained in a fluid sol state in the extruder 101 by the heat generated by the heating element 104, and can flow into the nozzle 102.

[0044] If the filament that has flowed into the nozzle 102 needs to contain air bubbles, it is energized to contain air bubbles through the electrolysis described above. Regardless of whether or not it contains air bubbles, the filament that has flowed into the nozzle 102 is also affected by gravity and is discharged from the nozzle 102 to the discharge destination.

[0045] Because 3D printing is a technology for creating three-dimensional objects, the filament ejected from the nozzle 102 must have low fluidity and be capable of forming a three-dimensional shape. For this reason, the filament contains a coagulant. In other words, the filament contains a coagulant to solidify.

[0046] In the electrolysis of water by energization, oxygen is produced at the anode and hydrogen is produced at the cathode of the electrode pair 105. An example of a circuit (i.e., energization circuit 106) that controls the energization of the electrode pair 105 is shown below.

[0047] 2 is a diagram illustrating an example of the energization circuit 106 according to the embodiment. The energization circuit 106 includes a first resistor 161, a switch 162, a circuit control unit 163, a second resistor 164, a transistor 165, a third resistor 166, a cathode 121, a power source 167, and an anode 122.

[0048] In Fig. 2, dotted lines connect positions that are grounded and therefore have the same potential level. The positions connected by dotted lines in the circuit in Fig. 2 are positions P1, P2, P3, and P4. Therefore, more specifically, the dotted lines in Fig. 2 indicate that the potential levels of positions P1, P2, P3, and P4 connected to each other by the dotted lines are ground (GND).

[0049] The first resistor 161 is a resistor having one end (position P1) grounded and the other end connected to the switch 162. The switch 162 is a switch having one end connected to the first resistor and the other end connected to a constant voltage source. When a current flows through the switch 162, the energizing circuit 106 is turned on, and when no current flows through the switch 162, the energizing circuit 106 is turned off.

[0050] The circuit control unit 163 includes a processor 95 such as a CPU, GPU, or NPU, and a memory 96, which are connected by a bus, and executes a program. One end of the circuit control unit 163 is connected to the end of the switch 162 that is connected to the first resistor, and the other end is connected to a second resistor 164. The second resistor 164 is a resistor having one end connected to the circuit control unit 163 and the other end connected to a third resistor 166 and a transistor 165. The third resistor 166 is a resistor having one end connected to the second resistor 164 and the transistor 165, and the other end (position P2) grounded.

[0051] The circuit control unit 163 controls the on and off states of the transistor 165 by executing a program. More specifically, when a current flows through the switch 162, the circuit control unit 163 detects the current flowing through the switch 162. Upon detecting the current, the circuit control unit 163 outputs a control signal that controls the operation of the transistor 165. The control signal is specifically a voltage with a predetermined amplitude and waveform, and the output of the control signal is specifically the application of a predetermined voltage. Therefore, more specifically, upon detecting the current, the circuit control unit 163 applies a predetermined voltage to the transistor 165 via the second resistor 164.

[0052] The transistor 165 is connected to the second resistor 164, the third resistor 166, and the cathode 121. The transistor 165 is, for example, a three-pole transistor, with one of the three poles connected to the second resistor 164, another of the three poles connected to the cathode 121, and the remaining one of the three poles (position P3) grounded. The cathode 121 is the cathode of the electrode pair 105.

[0053] The operation of the transistor 165 is controlled by the circuit control section 163, and when the transistor 165 receives a control signal from the circuit control section 163, it applies a voltage to the cathode 121. Such a transistor 165 is, for example, a field effect transistor (FET).

[0054] In fact, in the energization circuit 106, a voltage is applied to the anode 122 regardless of the state of the switch 162. The anode 122 is the anode of the electrode pair 105. The voltage is applied to the anode 122 by a power supply 167. The power supply 167 is a DC voltage source, one end of which (position P4) is grounded and the other end of which is connected to the anode 122. The power supply 167 applies a voltage to the anode 122. The voltage output by the power supply 167 may be controlled by the printer control unit 11.

[0055] Therefore, when a current flows through the switch 162, a voltage is also applied to the cathode 121. Therefore, when a filament is located between the cathode 121 and the anode 122, electrolysis of water occurs within the filament.

[0056] 3 is a diagram showing an example of control of the state of the switch 162 in this embodiment. The switch 162 is installed so that it can be contacted while the extruder 101 is moving, for example. In the example of FIG. 3, the switch 162 is pressed when the extruder 101 moves in the direction indicated by the arrow Y901. When the switch 162 is pressed, a current flows through the switch 162. As a result, electricity is applied to the filament in the nozzle 102 by the electrode pair 105, and water is electrolyzed within the filament in the nozzle 102.

[0057] In this way, since electrolysis can be controlled by, for example, pressing the switch 162 on the extruder 101, the user can obtain a modeling target having air bubbles inside with higher accuracy by designing the movement path of the extruder 101 and the position of the switch 162 according to the modeling target. In addition, the user can include air bubbles in the modeling target at any timing.

[0058] It should be noted that the state of the switch 162 does not necessarily have to be controlled by pressing it down with the extruder 101 as in the example of Fig. 3. For example, the switch 162 may be a transistor, and in such a case, the printer control unit 11 may control the operation of this transistor to control the state of the switch 162.

[0059] If switch 162 is a transistor, the conduction state of the transistor is controlled by the presence or absence of application of a voltage, but the voltage does not necessarily have to be applied directly by printer control unit 11. For example, printer control unit 11 may send a signal to a device that applies a voltage to the transistor, and control the operation of that device to apply a voltage to the transistor and control the state of switch 162. Such signal transmission may be wired or wireless.

[0060] Therefore, the control of the switch 162 by the printer control unit 11 may be wired or wireless.

[0061] <Relationship Between Print Data and Control of Switch 162> The following describes the relationship between print data and control of switch 162. Based on the print data, the printer control unit 11 sets the state of switch 162 to an energized state (i.e., a state in which current flows) when forming an area indicated by the print data as an area containing air bubbles.

[0062] <Example of Print Data Generation> Here, an example of the flow of generating print data according to user input will be described, taking as an example a case where print data is generated by the data generating device 2. The user inputs three-dimensional data indicating the shape and size of a modeling target (hereinafter referred to as “user-input three-dimensional data”) to the data generating device 2. The data generation control unit 21 acquires the user-input three-dimensional data input to the data generating device 2.

[0063] Next, the data generation control unit 21 divides the image having the shape and size indicated by the user-input three-dimensional data into a plurality of regions. The division of the regions may be performed by any method, such as a region division method used in the finite element method. Therefore, the division of the regions is, for example, a process of dividing the region into meshes. The size of the meshes is, for example, a size that follows a predetermined rule.

[0064] Next, the user sets whether or not each of the regions resulting from the division contains bubbles by operating a user interface provided in the data generating device 2. Furthermore, the user may set the degree of bubbles contained in each of the regions containing bubbles.

[0065] Next, the data generation control unit 21 assigns a pass number to each region according to a predetermined rule. In three-dimensional printing, a model is created by stacking layers. Therefore, pass numbers are assigned so that the model is created by stacking layers. Note that the data generation control unit 21 does not necessarily have to assign pass numbers automatically; the user may assign pass numbers to each region one by one. In this way, print data is generated.

[0066] 4 is a diagram showing an example of the hardware configuration of the three-dimensional printer 1 in an embodiment. The three-dimensional printer 1 is equipped with a printer control unit 11 including a processor 91 and a memory 92, and executes a program. By executing the program, the three-dimensional printer 1 functions as a device including the printer control unit 11, an interface unit 12, a storage unit 13, an extruder 101 including a heating element 104, a nozzle 102 including an electrode pair 105, a movement controller 103, and an energization circuit 106.

[0067] More specifically, the processor 91 reads out a program stored in the storage unit 13 and stores the read out program in the memory 92. When the processor 91 executes the program stored in the memory 92, the three-dimensional printer 1 functions as a device including a printer control unit 11, an interface unit 12, a storage unit 13, an extruder 101 including a heating element 104, a nozzle 102 including an electrode pair 105, a movement controller 103, and an energization circuit 106.

[0068] The printer control unit 11 controls the operation of each functional unit included in the three-dimensional printer 1. The printer control unit 11 controls the operation of each functional unit included in the three-dimensional printer 1, for example, in accordance with print data.

[0069] Therefore, the printer control unit 11 controls the operation of the movement controller 103 to control the movement of the extruder 101 so that modeling is performed in accordance with the pass number indicated by the print data, for example. Furthermore, when modeling an area that the print data indicates contains air bubbles, the printer control unit 11 controls the state of the energization circuit 106 by controlling the switch 162, and energizes the filament via the electrode pair 105.

[0070] Additionally, the printer control unit 11 may, for example, as described above, control the operation of the extruder 101 to control the amount of filament extruded per unit time from the nozzle 102. The printer control unit 11 may, for example, control the voltage output by the power supply 167. The printer control unit 11 may, for example, control the heat generation of the heating element 104.

[0071] Printer control unit 11 may communicate with a communication target, for example, via interface unit 12. Printer control unit 11 may, for example, acquire information stored in memory unit 13. Specifically, the process of acquiring information stored in memory unit 13 is reading.

[0072] The interface unit 12 includes a communication interface for connecting the 3D printer 1 to an external device. The interface unit 12 communicates with the external device via wired or wireless communication. The external device is, for example, a device that transmits print data, such as the data generation device 2. The interface unit 12 acquires print data through communication with the device that transmits the print data.

[0073] The interface unit 12 is configured to include input devices such as a mouse, keyboard, touch panel, etc. The interface unit 12 may be configured as an interface that connects these input devices to the 3D printer 1. In this way, the interface unit 12 accepts input of various information to the 3D printer 1 via the input device, either wired or wireless. Note that print data does not necessarily have to be input to the communication interface, but may also be input to the input device.

[0074] The interface unit 12 outputs various types of information. The interface unit 12 includes a display device such as a CRT (Cathode Ray Tube) display, a liquid crystal display, or an organic EL (Electro-Luminescence) display. The interface unit 12 may be configured as an interface that connects these display devices to the three-dimensional printer 1. The interface unit 12 outputs information that has been input to, for example, a communication interface or an input device of the interface unit 12.

[0075] The storage unit 13 is configured using a computer-readable storage medium (non-transitory computer-readable recording medium) such as a magnetic hard disk drive or semiconductor storage device. The storage unit 13 stores various information related to the 3D printer 1. The storage unit 13 stores, for example, various information generated by the operation of the printer control unit 11. Therefore, the storage unit 13 stores, for example, information indicating the control history of the heating element 104, the extruder 101, the electrode pair 105, the movement controller 103, and the energization circuit 106. The storage unit 13 stores, for example, information input to the interface unit 12.

[0076] 5 is a diagram showing an example of the hardware configuration of the data generating device 2 in an embodiment. The data generating device 2 includes a data generation control unit 21 including a processor 93 such as a CPU, GPU, or NPU, and a memory 94, which are connected via a bus, and executes a program. By executing the program, the data generating device 2 functions as a device including the data generation control unit 21, an interface unit 22, and a storage unit 23.

[0077] More specifically, the processor 93 reads the program stored in the storage unit 23 and stores the read program in the memory 94. The processor 93 executes the program stored in the memory 94, causing the data generating device 2 to function as a device including the data generation control unit 21, the interface unit 22, and the storage unit 23.

[0078] The data generation control unit 21 controls the operation of each functional unit included in the data generation device 2. The data generation control unit 21 generates print data, for example, in accordance with a user's instruction. The user's instruction is input to the interface unit 22. The data generation control unit 21 communicates with a communication target, for example, via the interface unit 22. The data generation control unit 21, for example, acquires information stored in the memory unit 23. Specifically, the process of acquiring information stored in the memory unit 23 is reading.

[0079] The interface unit 22 includes a communication interface for connecting the data generating device 2 to an external device. The interface unit 22 communicates with the external device via wired or wireless communication. The external device is, for example, the 3D printer 1. The interface unit 22 transmits print data to the 3D printer 1 through communication with the 3D printer 1.

[0080] The interface unit 22 includes input devices such as a mouse, a keyboard, and a touch panel. The interface unit 22 may be configured as an interface that connects these input devices to the data generation device 2. In this way, the interface unit 22 accepts input of various information to the data generation device 2 via the input devices, either wired or wireless.

[0081] The interface unit 22 outputs various types of information. The interface unit 22 includes a display device such as a CRT display, a liquid crystal display, or an organic EL display. The interface unit 22 may be configured as an interface that connects these display devices to the data generating device 2. The interface unit 22 outputs information input to, for example, a communication interface or an input device of the interface unit 22.

[0082] The storage unit 23 is configured using a computer-readable storage medium device such as a magnetic hard disk device or a semiconductor storage device. The storage unit 23 stores various information related to the data generation device 2. The storage unit 23 stores various information generated by the operation of the data generation control unit 21, for example.

[0083] <Example of Processing Flow> Fig. 6 is a flowchart showing an example of the flow of processing executed by the three-dimensional printer 1 according to the embodiment. In the example of Fig. 6, print data has been input in advance to the three-dimensional printer 1. Furthermore, the object to be modeled indicated by the print data includes an area containing air bubbles.

[0084] An instruction to start 3D printing is input to the interface unit 12 of the 3D printer 1 (step S101). The instruction to start 3D printing is input by, for example, a user.

[0085] Next, the printer control unit 11 models the object to be modeled according to the print data (step S102). Therefore, in step S102, the printer control unit 11 controls the movement of the extruder 101 so that the extruder 101 presses the switch 162, thereby controlling the energization of the electrode pair 105 according to the print data. Also, in step S102, the printer control unit 11 controls the amount of filament extruded from the nozzle 102 per unit time.

[0086] In step S102, the printer control unit 11 also controls the heat generation of the heating element 104 to inject the filament into the nozzle 102. In step S102, the printer control unit 11 also controls the movement controller 103 to move the extruder 101 so that modeling is performed in accordance with the pass number indicated in the print data.

[0087] The printing speed in step S102 is, for example, 3 mm / s. If the modeling is performed by stacking layers in step S102, a 60-second pause may be performed after printing each layer. This 60-second pause allows the filament, which has been melted by the heat from the heating element 104, to solidify.

[0088] If the print data indicates the amount of bubbles per unit volume of each region, the printer control unit 11 may change the strength of the current flow according to the amount of bubbles per unit volume of each region indicated by the print data. The strength of the current flow, specifically, refers to the strength of the voltage between the cathode 121 and the anode 122.

[0089] For example, when forming an area with a large amount of bubbles per unit volume, the printer control unit 11 increases the strength of the voltage between the cathode 121 and the anode 122 more than in an area with a smaller amount of bubbles per unit volume. Specifically, the control of the strength of the current is the control of the voltage output by the power supply 167.

[0090] When the formation of a region containing bubbles is performed after the formation of a region not containing bubbles, filaments not containing bubbles may remain in the nozzle 102. If these remaining filaments are ejected during the formation of the region containing bubbles, the accuracy of the formation will decrease.

[0091] Therefore, if the formation of an area containing air bubbles is performed after the formation of an area not containing air bubbles, the filament remaining in the nozzle 102 may be ejected to a location that will not be formed before the formation of the area containing air bubbles.

[0092] Furthermore, after the region containing the bubbles has been modeled, the filaments remaining in the nozzle 102 may be ejected to a location that will not be modeled before the next region is modeled.

[0093] <Experimental Results> An example of the experimental results using the 3D printer 1 will be described with reference to Fig. 7. The experiment involved applying pressure to an object modeled by the 3D printer 1 using a filament made of a mixture of orange juice, gelatin, sugar, and an aqueous sodium sulfate solution in a component ratio of 5:1:1:0.2.

[0094] The objects used in the experiment were two- or three-layered gummies, each containing air bubbles in one layer. Five types of gummies with different amounts of air bubbles per unit volume were used in the experiment. Specifically, five types of gummies were used, with the ratios of gummies containing air bubbles generated when 27 V and 18 mA of current were applied to the gummies being 0%, 30%, 50%, 70%, and 100% of the total gummies. Note that 100% refers to a state in which bubbles are present throughout the entire gummies.

[0095] Specifically, the pressure test was conducted by using a force tester to press a rod-shaped indenter against the gummy candy. In the experiment, the repulsive force of the gummy candy against the applied pressure was measured. The higher the repulsive force of the gummy candy, the more elastic it is. Gummy candy is eaten because it is a snack. The difference in repulsive force is felt by the person eating the gummy candy as a difference in texture when chewing it.

[0096] FIG. 7 is a diagram showing an example of experimental results in an embodiment. The horizontal axis of FIG. 7 represents distance. Specifically, distance means how far the rod-shaped indenter that applies pressure has moved from the origin. The greater the distance moved from the origin, the greater the pressure applied to the gummies. The vertical axis of FIG. 7 represents the repulsive force of the gummies. The repulsive force of the gummies is defined as the force applied to the indenter when the gummies are compressed by the indenter.

[0097] The "0%" graph in FIG. 7 represents the experimental results for gummy candies with 0% air bubbles per unit volume. The "30%" graph in FIG. 7 represents the experimental results for gummy candies with 30% air bubbles per unit volume. The "50%" graph in FIG. 7 represents the experimental results for gummy candies with 50% air bubbles per unit volume. The "70%" graph in FIG. 7 represents the experimental results for gummy candies with 70% air bubbles per unit volume. The "100%" graph in FIG. 7 represents the experimental results for gummy candies with 100% air bubbles per unit volume.

[0098] The results in Figure 7 show that as the pressure applied to the gummy candy increases, the repulsive force increases up to a distance of approximately 9 mm. The results in Figure 7 also show that the gummy candy breaks when the distance exceeds approximately 9 mm. More specifically, the point at a distance of approximately 9 mm in the results in Figure 7 is the yield point, and the results in Figure 7 show that the gummy candy breaks when the repulsive feeling reaches the yield point. When the gummy candy is eaten, the breakage state refers to the state in which the gummy candy is torn apart.

[0099] The results in Figure 7 show that even if the amount of bubbles per unit volume is different, the elasticity exhibited when the distance reaches 10 mm is approximately the same. The results in Figure 7 also show that different amounts of bubbles per unit volume result in different susceptibility to rupture. The results in Figure 7 also show that the greater the amount of bubbles per unit volume, the smaller the maximum value that appears at a distance of approximately 9 mm, making it easier to rupture.

[0100] As such, the results of Figure 7 show that the three-dimensional printer 1 can generate gummies that are more easily broken than gummies that do not contain air bubbles, even though the elastic force (repulsive force) is roughly the same.

[0101] This type of gummy candy is difficult to produce using three-dimensional modeling techniques that generate bubbles by heating, as the accuracy of bubble generation is an issue, but it can be produced more easily than by heating using the three-dimensional printer 1 that generates bubbles by passing electricity through it.

[0102] (Application Examples) The three-dimensional printer 1 can take advantage of the high accuracy of air bubble generation to create a product in which multiple layers with different amounts of air bubbles per unit volume are stacked side by side. The three-dimensional printer 1 can also create gummy candies that have different textures depending on the direction of chewing, for example. The three-dimensional printer 1 can also create gummy candies with a texture that corresponds to visual information, such as a turtle-shaped gummy candy where only the gummy candy used for the turtle's body contains air bubbles and is softer than the gummy candy used for the shell.

[0103] The 3D printer 1 configured in this manner includes an electrode pair 105 and applies current to the filament. As a result, as described in <Technical Significance of Current Application by Electrode Pairs and Significance of Coagulant>, the 3D printer 1 can generate bubbles with greater accuracy than bubbles generated by heating. Therefore, the 3D printer 1 can improve the accuracy of forming 3D objects with bubbles inside.

[0104] The 3D printing system 100 configured in this manner also includes the 3D printer 1. Therefore, the 3D printing system 100 can improve the accuracy of forming a 3D object having an air bubble therein.

[0105] (Variation) It should be noted that the printer control unit 11 does not necessarily have to control the amount of filament discharged per unit time from the nozzle 102. For example, depending on the object to be modeled, the filament may be allowed to melt and flow out of the nozzle 102 naturally.

[0106] It should be noted that the printer control unit 11 does not necessarily have to control the heat generation of the heating element 104. For example, the power supply that supplies power to the heating element 104 may not be controlled by the printer control unit 11, but may be turned on and off by the user. In such a case, the heating element 104 can radiate a certain amount of heat without being controlled by the printer control unit 11 simply by the user turning on the power supply that supplies power to the heating element 104.

[0107] The electrode pair 105 may be located at any position as long as it is a position where current can be applied to the filament in a melted state after heating by the heating element 104. Therefore, it is not necessarily required that the electrode pair 105 be provided in the nozzle 102.

[0108] It should be noted that the printer control unit 11 does not necessarily have to control the movement of the movement controller 103. For example, when the 3D printer 1 generates a rod-shaped object such as a tower, the extruder 101 does not need to move during 3D printing, and it is sufficient if it remains in the pre-installed position. In this way, the printer control unit 11 does not necessarily have to control the movement of the movement controller 103.

[0109] The printer control unit 11 may be implemented using a plurality of information processing devices connected to each other via a network so that the processes performed by the printer control unit 11 may be distributed among the plurality of information processing devices.

[0110] The data generation control unit 21 may be implemented using a plurality of information processing devices connected to each other via a network so that they can communicate with each other. In this case, the processes executed by the data generation control unit 21 may be distributed and executed by the plurality of information processing devices.

[0111] The three-dimensional printer 1 and the data generating device 2 do not necessarily have to be mounted in different devices, but may be mounted in a single housing.

[0112] Note that all or part of the functions of the three-dimensional printing system 100 may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The program may be recorded on a computer-readable recording medium. Examples of computer-readable recording media include portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into computer systems. The program may be transmitted via a telecommunications line.

[0113] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention.

[0114] 100...3D printing system, 1...3D printer, 2...data generation device, 11...printer control unit, 12...interface unit, 13...memory unit, 101...extruder, 102...nozzle, 103...movement controller, 104...heating element, 105...electrode pair, 106...energizing circuit, 161...first resistor, 162...switch, 163...circuit control unit, 164...second resistor, 165...transistor, 166...third resistor, 167...power supply, 121...cathode, 122...anode, 21...data generation control unit, 22...interface unit, 23...memory unit, 91...processor, 92...memory, 93...processor, 94...memory, 95...processor, 96...memory

Claims

1. A 3D printer that executes 3D printing, comprising: a heating element that applies heat to a filament; an electrode pair that energizes the filament in a melted state after being heated by the heating element; and a control unit that controls the energization by the electrode pair, wherein the filament is a thermoplastic substance having water with conductivity and a coagulant.

2. The 3D printer according to claim 1, wherein the filament is a mixture of an edible substance containing water with conductivity and an edible coagulant.

3. The 3D printer according to claim 2, wherein the edible coagulant is gelatin.

4. The 3D printer according to claim 2, wherein the edible coagulant is sugar.

5. The 3D printer according to claim 2, wherein the edible substance containing water with conductivity is juice.

6. The 3D printer according to claim 2, wherein the edible substance containing water with conductivity is an aqueous sodium sulfate solution.

7. A 3D printing method executed by a 3D printer that executes 3D printing, the 3D printer comprising: a heating element that applies heat to a filament; an electrode pair that energizes the filament in a melted state after being heated by the heating element; and a control unit that controls the energization by the electrode pair, wherein the filament is a thermoplastic substance having water with conductivity and a coagulant, the method comprising: a control step of the control unit controlling the energization by the electrode pair.

8. A program for causing a computer to function as the 3D printer according to any one of claims 1 to 6.

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