JP2018145463A - Method for producing laminate-shaping powder, reproducing method, reproducing apparatus, and apparatus for producing three-dimensionally shaped article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing powder which can be used as a material from powder used during laminate shaping.SOLUTION: A method includes: a classification step (S12) with a sieving screen, of classifying powder (20) remaining after fabricating a three-dimensionally shaped article, by using the sieving screen; a classification step (S13) with air current, of classifying powder (40) remaining in the sieving screen in the classification step with a sieving screen into fine-particle powder and coarse particle powder, with the air current; and a mixing step (S14) for mixing the fine particles with powder (30) having passed through the sieving screen in the classification step with a sieving screen, and new powder (10).SELECTED DRAWING: Figure 3

Description

  The present invention relates to an additive manufacturing method, a reproducing method, a reproducing apparatus, and a three-dimensional structure manufacturing apparatus.

  There is a technique for manufacturing parts / products using additive manufacturing. As a specific method of additive manufacturing, a powder bed method such as a selective laser burning method (SLS) is included. In this method, first, powder is spread in layers, and the surface is formed flat with a coater or the like. Next, a part of this layer is melted and bonded with a laser or the like. A layer in which powder is spread is formed again on the melted and bonded layer, and melted and bonded with a laser or the like. By repeating this, parts and products are manufactured.

  In order to maintain the accuracy of the parts manufactured by this additive manufacturing, uniform fine powder is used as the material powder by air classification. Patent Document 1 discloses a method in which airflow classification is performed on powder that has passed through a sieve screen, and the powder is classified into three types: powder before passing through the sieve screen, and two types of powder classified by airflow classification. Yes.

  Moreover, in order to reduce the amount of powder to be discarded, a method for collecting and using the powder removed by the coater when spreading the powder is disclosed (for example, Patent Document 2).

  In additive manufacturing, the spread powder is selectively melted and bonded with a laser or the like, so that part of the spread powder is not melted or bonded with a laser or the like. Here, it is disclosed that powder that has not been melted and bonded is classified by a sieve screen and reused (for example, Patent Document 3).

JP 2001-79494 A JP 2007-307742 A Japanese Patent No. 4737007

  The applicant has found that even when powder that has not been melted or bonded is classified with a sieve mesh, the fine powder adheres to the debris and is contained in a considerable amount in the powder that does not pass through the sieve mesh. Focusing on this point, an object of the present invention is to provide a method for efficiently producing a usable powder for additive manufacturing from the powder used in additive manufacturing. Other objects can be understood from the following description and the description of the embodiments.

  Hereinafter, means for solving the problem will be described using the numbers and symbols used in the embodiments for carrying out the invention. These numbers and symbols are added with parentheses for reference in order to show an example of the correspondence between the description of the claims and the mode for carrying out the invention. Accordingly, the claims should not be construed as limiting due to the bracketed description.

  In order to achieve the above object, the method for producing a layered modeling powder according to the first aspect of the present invention includes a sieve net classification step of classifying a powder (20) remaining after molding by layered modeling using a sieve net. (S12), an airflow classification step (S13, S1303, S1312) for classifying the powder (40) remaining on the sieve net in the sieve mesh classification step into fine particle powder and coarse particle powder, and fine particle powder, It includes a mixing step (S14) of mixing the powder (30) that has passed through the sieve net in the sieve net classification step and a new powder.

  The airflow classification step includes the step of measuring the particle size distribution of the powder remaining on the sieve screen (S1301), the step of determining the classification point based on the measured particle size distribution (S1302), and the classification point. A step of classifying the remaining powder into a fine particle powder and a coarse particle powder (S1303).

  You may determine the classification point of an airflow classification process to the particle size in which the volume ratio of the measured particle size distribution shows a minimum value (48).

  In the mixing step described above, the mass of the new powder to be mixed may be determined based on the mass of the fine particle powder and the powder (30) that has passed through the sieve mesh.

  In the mixing step described above, the fine particle powder, the powder (30) that has passed through the sieve net, and the new powder may be stirred and mixed.

  Furthermore, a pulverizing step (S1311) of pulverizing the powder remaining on the sieve net may be included.

  In the method for regenerating a layered modeling powder according to the second aspect of the present invention, a sieve net classification step (S12) of classifying a powder (20) remaining after molding a three-dimensional model using a sieve net, and a sieve Airflow classification process (S13, S1303, S1312) for classifying the powder (40) remaining in the sieve mesh in the mesh classification process into fine particle powder and coarse particle powder, fine particle powder, and sieving in the sieve mesh classification process It includes a mixing step (S14) of mixing the powder (30) that has passed through the net and a new powder.

  According to a third aspect of the present invention, there is provided an apparatus for regenerating a layered modeling powder, a sieve net classification unit (102) for classifying a powder (20) remaining after molding a three-dimensional model using a sieve net, and a sieve. The powder (40) remaining on the sieve mesh in the mesh classification part is passed through the sieve mesh in the air classification part (104) for classifying the fine powder and coarse powder into the air stream, the fine particle powder, and the sieve mesh classification part. A mixing unit (106) for mixing the powder (30) and the new powder is provided.

  A manufacturing apparatus for a three-dimensional structure according to the fourth aspect of the present invention includes a reproduction apparatus (100) for the above-described additive manufacturing powder, a molding unit (202) for forming the three-dimensional structure by additive manufacturing, and a reproduction. A powder injection part (201) for injecting the powder produced by the apparatus into the molding part. The regenerator further includes a powder recovery unit (101) for recovering the used powder (20) remaining after the molding.

  According to the present invention, usable powder for additive manufacturing can be efficiently produced from the powder used in additive manufacturing.

It is a schematic diagram of the powder before using it for additive manufacturing. It is a graph which shows the particle size distribution of the powder before using it for an additive manufacturing. It is a schematic diagram of the powder after using it for additive manufacturing. It is a graph which shows the particle size distribution of the powder after using it for an additive manufacturing. It is a flowchart regarding the process of the manufacturing method of the powder which concerns on this Embodiment 1. It is a schematic diagram of the powder which passed the sieve net. It is a graph which shows the particle size distribution of the powder which passed the sieve net. It is a schematic diagram of the powder which remained in the sieve net. It is a graph which shows the particle size distribution of the powder which remained in the sieve net | network. It is a flowchart regarding the process of the manufacturing method of the powder which concerns on this Embodiment 2. It is a flowchart regarding the process of the manufacturing method of the powder which concerns on this Embodiment 3. It is a schematic diagram of the powder reproduction | regeneration apparatus which concerns on this Embodiment 4. FIG. 10 is a schematic diagram of a 3D printer according to a fifth embodiment. It is a schematic diagram of a 3D printer.

  A 3D printer is mentioned as an apparatus which manufactures components by additive manufacturing. As shown in FIG. 10, the powder bed type 3D printer 1000 includes a control unit 1001, a laser irradiation unit 1002, a powder injection unit 1003, a coater 1004, a base plate 1005, and a manufacturing container 1006.

  The control unit 1001 controls the 3D printer 1000 such as the laser irradiation position of the laser irradiation unit 1002, the position of the base plate 1005, the control of the coater 1004, and the injection of the powder 1007 by the powder injection unit 1003. The control unit 1001 controls each unit of the 3D printer 1000 based on the structure data created by the computer 2000. As a result, the 3D printer 1000 forms a part by additive manufacturing.

  When forming a three-dimensional structure with the 3D printer 1000, first, the powder 1007 to be melted and bonded by laser irradiation is injected from the powder injection unit 1003 onto the base plate 1005, that is, into the manufacturing container 1006. Next, the coater 1004 is controlled to flatten the surface of the powder 1007. Subsequently, a laser is irradiated from the laser irradiation unit 1002 in accordance with the structure of the three-dimensional structure, and the powder 1007 is selectively melted and bonded. As a result, the first layer forming portion 1008 is formed.

  Next, the base plate 1005 is lowered to melt and bond the second layer molding part 1009. Again, powder 1007 is injected. The coater 1004 is controlled to flatten the surface of the powder 1007. Laser irradiation is performed from the laser irradiation unit 1002, and the second layer forming unit 1009 is formed.

  By repeating this, the 3D printer 1000 forms a three-dimensional shaped object. That is, the 3D printer 1000 forms a three-dimensional structure by melting and bonding a part of the powder 1007 injected into the manufacturing container 1006. As a result, part of the powder 1007 injected into the manufacturing container 1006 remains in the manufacturing container 1006 without being melted and bonded. From the used powder remaining in the manufacturing container 1006, a usable powder for additive manufacturing is manufactured again.

  The powder 10 before forming the three-dimensional structure is composed of fine particles 11 as shown in FIG. 1A. As shown in FIG. 1B, when the particle size distribution 15 of the powder 10 is expressed by the logarithm of the particle size on the horizontal axis, the volume ratio decreases with increasing distance from the particle size 16 centering on the particle size 16 having the maximum volume ratio. The distribution is as follows. In the present application, the particle size 16 having a maximum volume ratio of the particle size distribution 15 is referred to as a central particle size. The center particle size 16 of the additive manufacturing powder 10 is, for example, 32 μm.

  Here, the particle size distribution is measured based on a laser diffraction / scattering method based on ISO 13320: 2009 and JIS Z8825-2. Specifically, the dispersed particles are irradiated with laser light, and the angle dependency of the intensity of scattered light from the particles is measured. Thereby, distribution with respect to the particle size of particle | grains is measured. By this method, 1-second measurement is performed three times, and the particle size distribution is measured from the average of the three times. Here, remeasurement is performed when there is an error of 1% or more in the center particle diameter of the measured powder. Using this method, the particle size distribution is measured.

  On the other hand, as shown in FIG. 2A, the used powder 20 remaining in the manufacturing container 1006 after forming the three-dimensional structure includes fine particles 21 and coarse particles 22 melted and bonded by a laser. It is. As shown in FIG. 2B, the particle size distribution 25 of the used powder 20 is a distribution obtained by combining the particle size distribution of the powder composed of the fine particles 21 and the particle size distribution of the powder composed of the coarse particles 22. The center particle size 26 of the powder composed of the fine particles 21 is, for example, 32 μm and approximates to the powder 10 before molding. On the other hand, the center particle size 27 of the powder composed of the coarse particles 22 is, for example, 120 μm, and is larger than the center particle size of the powder 10 before molding. Therefore, the used powder 20 is separated into a powder composed of fine particles 21 and a powder composed of coarse particles 22 in order to produce a powder approximate to the size of the particles constituting the powder 10 before molding. As a result, the powder composed of the fine particles 21 can be taken out and a usable powder can be produced again.

  Here, there is an air classification as a method of separating the powder. Airflow classification uses the fact that the distance from the pop-out position to the floor changes depending on the size of the particles by flying the particles on the airflow from a certain height. Airflow classification includes centrifugal force field classification, gravity field classification, inertial force field classification, and the like. Airflow classification also includes classification using the effect of centrifugal force and airflow. Specifically, the particles are moved circularly and a centrifugal force is applied to the particles. In this centrifugal force field, an airflow is generated in the opposite direction to the centrifugal force, that is, from the outside of the circle toward the center. This air flow exerts the opposite effect of centrifugal force on the particles. Thereby, since the particle | grains with a large particle size have large centrifugal force, they move to the outward direction of a circle | round | yen by centrifugal force. On the other hand, particles having a small particle size are more effective than centrifugal force, and therefore move in the center direction of the circle due to the effect. In this way, the powder is separated. In this case, the classification point is determined by the rotational speed of the circular motion, the flow rate of the air flow, the specific gravity of the material, and the like.

  As a method for separating powder, there is a classification method using a sieve screen. Particles larger than the opening of the sieve screen will remain unable to pass through the sieve screen. On the other hand, particles smaller than the opening of the sieve mesh pass through the sieve mesh. In this way, the powder is separated based on the size of the particles. There are various classification methods using a sieve net, such as a gyro shifter and a square shifter.

(Embodiment 1)
After the three-dimensional structure is formed using the 3D printer, the powder manufacturing method 1 that can be used again from the powder 20 remaining in the manufacturing container 1006 will be described.

  First, as shown in FIG. 3, in step S11, the powder 20 remaining in the production container 1006 is collected.

  Next, in step S12, in order to remove coarse particles 22 that cannot be used as a material from the powder 20, the powder 20 is classified using a sieve screen. The classification point of this classification, that is, the size of the opening of the sieve net is determined in advance from the height of the layered layer produced using the powder. For example, the classification point is 100 μm or the like. For this classification, any method using a sieve screen can be selected.

  As a result, it can classify | categorize into the powder 30 which passed the sieve mesh, and the powder 40 which remained in the sieve mesh. The powder 30 that has passed through the sieve net is composed of fine particles 21 as shown in FIG. 4A. As shown in FIG. 4B, the particle size distribution 35 of the powder 30 that has passed through the sieve mesh approximates the particle size distribution 15 of the powder 10 before use.

  On the other hand, as shown in FIG. 5A, the powder 40 remaining on the sieve net includes fine particles 21 attached to the coarse particles 22 in addition to the coarse particles 22. As shown in FIG. 5B, the particle size distribution 45 of the powder 40 remaining in the sieve net is obtained by dividing a powder having a center particle size 47 composed of coarse particles 22 and a powder having a center particle size 46 composed of fine particles 21. Combined distribution. Here, the powder having the center particle size 46 composed of the fine particles 21 occupies about 15% of the powder 40 remaining in the sieve net.

  For this reason, in step S <b> 13, the powder 40 remaining on the sieve net is air-flow classified, and the powder composed of the fine particles 21 is taken out. The classification point for this classification is determined in advance from the height of the layered layer produced using powder. As a result, the reusable fine particles 21 can be taken out from the powder 40 remaining on the sieve screen. For this classification, any method of airflow classification can be selected.

  In step S14, the powder 30 that has passed through the sieve screen in step S12, the fine powder extracted by airflow classification in step S13, and the new powder 10 are mixed to produce a usable powder. In other words, from the used powder 20, the powder 30 that has passed through the sieve screen and the powder that has been taken out after air classification are collected. A new powder 10 is added to the collected powder to produce a usable powder. Here, the mass of the new powder 10 to be added is a value obtained by adding the mass of the powder removed by the airflow classification in step S14 to the mass of the powder used for manufacturing the part. That is, the mass of the powder reduced by the molding of the three-dimensional structure and the manufacturing method 1.

  As described above, usable additive manufacturing powder can be manufactured from the powder 20 remaining in the manufacturing container 1006.

  In Embodiment 1, fine particles are taken out from the powder 40 remaining in the sieve net by airflow classification, so that the amount of powder to be discarded is small. Therefore, the ratio of the powder to be reused relative to the powder to be discarded, that is, the reuse rate is high.

  In addition, by mixing new powder in step S14, when the material is a metal, there is an effect of reducing the oxygen concentration after the parts are manufactured. When the oxygen concentration contained in the metal is high, the tensile strength, bending fatigue strength, and the like are low. Therefore, by adding new powder, the oxygen concentration of the part finally produced can be lowered. In order to obtain such an effect, it is desirable that the new powder and the used powder are stirred in step S14 so that the proportions of the powder in each place are uniformly mixed.

  As described above, Embodiment 1 is a particularly effective manufacturing method for metals such as stainless steel, aluminum, and titanium.

  Although an example of the mass of the new powder 10 added at step S14 was shown, it is not limited to this. For example, 2 parts by mass or more of new powder may be mixed with 23 parts by mass of the collected powder. That is, you may mix so that a new powder may become 8 mass% or more among the mixed powder. Thus, the oxygen concentration of the three-dimensional structure after manufacture can be controlled by determining the mass of the new powder to be added based on the mass of the collected powder. In particular, when the recycled powder is repeatedly manufactured and used by using this manufacturing method, the effect of maintaining the strength of the part is exhibited. Furthermore, you may mix 1 mass part or more of new powder with respect to 9 mass parts of the collect | recovered powder. In other words, you may mix so that a new powder may become 10 mass% or more among the mixed powder.

  In addition, as shown in FIG. 10, after the powder 1007 is injected into the production container 1006 from the powder injection unit 1003, the surface of the powder 1007 is flattened by the coater 1004. Specifically, the surface of the powder 1007 is flattened by moving the coater 1004 laterally at a constant height and removing excess powder 1007. The excess powder 1007 that has been removed may also be added to produce additive manufacturing powder. Here, the removed powder includes not only a new injected powder but also a powder melted and bonded by a laser or the like. For this reason, the powder removed before melting and adhering can be handled in the same manner as the powder 20 remaining in the manufacturing container 1006. Specifically, in step S11, the powder removed before bonding is added to the collected powder 20 to produce a layered modeling powder.

(Embodiment 2)
In the first embodiment, an example is shown in which the classification point in step S13 is determined in advance. In the second embodiment, a manufacturing method 1A for determining this classification point based on the particle size distribution of the powder will be described. Steps S11, S12, and S14 are the same as those in the first embodiment, and thus description thereof is omitted.

  As shown in FIG. 6, in step S1301, the particle size distribution 45 of the powder 40 remaining on the sieve net is measured. As a result, as shown in FIG. 5B, a particle size distribution such as a combination of the powder having the center particle size 46 and the powder having the center particle size 47 is obtained.

  In step S <b> 1302, a particle size 48 having a minimum volume ratio between the central particle size 46 and the central particle size 47 is calculated from the measured particle size distribution 45. The particle size 48 is suitable for separating the powder composed of the fine particles 21 and the powder composed of the coarse particles 22.

  In step S1303, the powder 40 remaining on the sieve screen is air-flow classified using the particle size 48 calculated in step S1302 as a classification point. As a result, particles smaller than the particle size 48, that is, powder composed of the fine particles 21 can be taken out.

  In step S14, the extracted powder, the powder that has passed through the sieve net in step S12, and the new powder are mixed. This produces a usable powder.

  As described above, the fine particle powder and the coarse particle powder can be classified based on the particle size distribution 45 of the powder 40 remaining on the sieve mesh. As shown in FIG. 5B, the powder 40 remaining in the sieve net contains many particles larger than the particle size 48, but by setting the classification point to the particle size 48, the powder centered on the central particle size 46 of the fine particle powder. Can be taken out. That is, the particle size distribution of the powder manufactured in the second embodiment does not include particles having a larger particle size than the particle size distribution of the powder manufactured in the first embodiment. In other words, few particles are melted and adhered by the laser. For this reason, parts manufactured using this powder can keep the oxygen concentration low.

  Also in step S12, as shown in FIG. 2B, classification may be performed between the central particle size 26 and the central particle size 27 using the particle size 28 in which the volume ratio of the particle size distribution is a minimum value as the classification point. .

(Embodiment 3)
In Embodiment 1, 2, the example classified from the used powder 20 according to the magnitude | size of particle | grains was shown. In the third embodiment, a manufacturing method 1B for increasing the amount of powder produced from the used powder 20 by pulverizing the powder remaining in the sieve net with a ball mill or the like will be described.

  Specifically, as shown in FIG. 7, in step S1311, the powder remaining on the sieve net is pulverized using a ball mill or the like. As a result, the coarse particles 22 are crushed and fine particles are increased.

  Next, in step S1312, airflow classification is performed on the pulverized powder. Thereby, the powder comprised from a fine particle is taken out from the powder grind | pulverized by step S1311.

  In step S14, the extracted powder, the powder that has passed through the sieve net in step S12, and the new powder are mixed. This produces a usable powder.

  As described above, fine particles can be increased by pulverizing the powder remaining in the sieve net. That is, the powder taken out from the used powder 20 as a usable powder increases. Therefore, this manufacturing method 1B has a higher reuse rate than manufacturing methods 1 and 1A.

  In the third embodiment, the method for determining the classification point of the airflow classification shown in the second embodiment may be applied. Specifically, when airflow classification is performed in step S1312, the particle size distribution of the crushed powder may be measured, and the classification point may be determined from the measured particle size distribution.

(Embodiment 4)
A powder regeneration apparatus for producing powder using the production method shown in the first to third embodiments will be described.

  As shown in FIG. 8, the powder regeneration apparatus 100 includes a powder recovery unit 101, a sieve mesh classification unit 102, a pulverization unit 103, an airflow classification unit 104, a powder supply unit 105, a mixing unit 106, and an output unit. 107.

  The powder recovery unit 101 recovers the used powder 20 in the manufacturing container 1006. That is, the powder collection | recovery part 101 performs the process corresponded to step S11 of the manufacturing methods 1, 1A, 1B. Specifically, the used powder 20 is sucked and collected by a suction machine or the like. Further, a collection container may be provided, and the used powder 20 may be put in the collection container.

  The sieve net classification unit 102 classifies the used powder 20 collected by the powder collection unit 101 using a sieve net. Thereby, the used powder 20 is separated into a powder composed of fine particles and a powder composed of coarse particles. That is, the sieve classification unit 102 performs a process corresponding to Step S12 of the manufacturing method 1, 1A, 1B.

  The pulverizing unit 103 pulverizes the powder remaining on the sieve net by the sieve net classifying unit 102 with a ball mill or the like. Processing corresponding to step S1311 of the manufacturing method 1B is performed.

  The airflow classifying unit 104 takes out fine particles from the powder pulverized by the pulverizing unit 103. That is, processing corresponding to Step S13 of Manufacturing Method 1, Steps S1301, S1302, and S1303 of Manufacturing Method 1A and Step S1312 of Manufacturing Method 1B is performed. Here, when the powder remaining on the sieve mesh is not pulverized, the powder remaining on the sieve mesh is classified by air flow in the sieve mesh classification unit 102 without using the pulverization unit 103.

  The powder supply unit 105 stores new powder and supplies it to the mixing unit 106 as necessary.

  The mixing unit 106 mixes the powder that has passed through the sieving screen of the sieving screen classifying unit 102, the powder taken out by the airflow classifying unit 104, and the new powder supplied from the powder supply unit 105. Processing corresponding to step S14 of manufacturing method 1, 1A, 1B is performed.

  The output unit 107 outputs the powder mixed by the mixing unit 106 as usable powder.

  The control unit 108 controls processing of each unit. Specifically, the control unit 108 controls the amount of used powder supplied to the sieve net classification unit 102, the start / end of pulverization of the pulverization unit 103, the classification point of the airflow classification unit 104, and the like. The control unit 108 also controls the amount of powder supplied from the powder supply unit 105 to the mixing unit 106.

  As described above, the powder regeneration apparatus 100 can produce a usable powder from a used powder by any one of the production methods 1, 1A, and 1B.

  In the case of producing a powder using the production methods 1 and 1A, the powder regenerating apparatus 100 may not include the pulverizing unit 103. In this case, the powder remaining on the sieve screen is directly supplied to the airflow classification unit 104 by the sieve screen classification unit 102.

  Moreover, when manufacturing powder using the method of manufacturing method 1A, you may include the measurement part which measures a particle size distribution in the airflow classification part 104. FIG. In this case, the particle size distribution of the powder pulverized by the pulverization unit 103 is measured by the measurement unit, and the result is transmitted to the control unit 108. Based on the measurement result, the control unit 108 calculates a classification point. The control unit 108 controls the airflow classifying unit 104 based on the calculated classification point to classify the pulverized powder.

  The powder recovery unit 101 may further recover the powder removed by the coater.

(Embodiment 5)
As shown in FIG. 9, the powder recycling apparatus 100 according to the fourth embodiment can be installed in the 3D printer 200.

  The 3D printer 200 includes a powder regeneration device 100, a powder injection unit 201, a molding unit 202, and a control unit 203.

  The powder reproduction | regeneration apparatus 100 manufactures the powder which can be used as a material from used powder as above-mentioned.

  The powder injection unit 201 stores the powder produced by the powder regeneration device 100. Moreover, when manufacturing a three-dimensional structure, powder is supplied to the forming unit 202. Specifically, as shown in FIG. 10, it has a function corresponding to the powder injection unit 1003 of the 3D printer 1000.

  The molding unit 202 manufactures a three-dimensional structure from the powder supplied from the powder injection unit 201. Specifically, as shown in FIG. 10, the forming unit 202 includes a laser irradiation unit 1002 of the 3D printer 1000, a coater 1004, a base plate 1005, and a manufacturing container 1006. The powder injected from the powder injection unit 201 is melted and bonded with a laser or the like to form a three-dimensional structure. The used powder remaining after forming the three-dimensional structure is recovered by the powder recovery unit 101 of the powder regeneration device 100.

  The control unit 203 controls each function of the powder regeneration device 100, the powder injection unit 201, and the molding unit 202. Specifically, as shown in FIG. 10, a control unit 1001 is provided to control the laser irradiation unit 1002, the coater 1004, and the like of the forming unit 202. In addition, the control unit 203 may have the function of the control unit 108 of the powder regeneration device 100.

1, 1A, 1B Production method 10 Powder before use 11 Fine particles 15 Particle size distribution of powder before use 16 Central particle size of powder before use 20 Powder after use 21 Fine particles 22 Coarse particles 25 Particle size distribution of powder after use 26 Fine Median particle size of particle powder 27 Median particle size of coarse particle powder 28 Particle size showing minimum value 30 Powder passing through sieve screen 35 Particle size distribution of powder passing through sieve screen 40 Powder remaining in sieve screen 45 Residual on sieve mesh Particle size distribution of fine powder 46 Central particle size of fine particle powder 47 Central particle size of coarse particle powder 48 Particle size showing minimum value 100 Powder regenerator 101 Powder recovery unit 102 Sieve net classification unit 103 Grinding unit 104 Airflow classification unit 105 Powder Supply unit 106 Mixing unit 107 Output unit 108 Control unit 200 3D printer 201 Powder injection unit 202 Molding unit 203 Control unit 100 DESCRIPTION OF SYMBOLS 0 3D printer 1001 Control part 1002 Laser irradiation part 1003 Powder injection | pouring part 1004 Coater 1005 Base plate 1006 Manufacturing container 1007 Powder 1008 1st layer shaping | molding part 1009 2nd layer shaping | molding part 1010 3rd layer shaping | molding part

Claims (9)

A sieve mesh classification step of classifying the powder remaining after molding by additive molding using a sieve mesh;
An airflow classification step of classifying the powder remaining in the sieve net in the sieve net classification step into an airflow classification into a fine particle powder and a coarse particle powder;
The manufacturing method of the powder for additive manufacturing including the fine particle powder, the mixing step of mixing the powder that has passed through the sieve net in the sieve net classification step, and a new powder. It is a manufacturing method of the powder for additive manufacturing according to claim 1,
The airflow classification step includes
Measuring the particle size distribution of the powder remaining in the sieve net;
A step of determining a classification point based on the measured particle size distribution;
And a step of air-classifying the powder remaining on the sieve net into the fine particle powder and the coarse particle powder at the classification point. A method for producing the additive manufacturing powder according to claim 2,
The manufacturing method of the powder for additive manufacturing, wherein the classification point in the airflow classification step is determined to be a particle size at which the volume ratio of the measured particle size distribution shows a minimum value. It is a manufacturing method of the powder for additive manufacturing according to any one of claims 1 to 3,
In the mixing step, the mass of the new powder to be mixed is determined based on the mass of the fine particle powder and the powder that has passed through the sieve net. It is a manufacturing method of the powder for layered modeling according to any one of claims 1 to 4,
The said mixing process stirs and mixes the said fine particle powder, the powder which passed the said sieve net | network, and the said new powder. The manufacturing method of the powder for layered modeling. It is a manufacturing method of the powder for additive fabrication according to any one of claims 1 to 5,
Furthermore, the manufacturing method of the powder for additive manufacturing including the grinding | pulverization process which grind | pulverizes the powder remaining on the said sieve net | network. A sieve mesh classification step of classifying the remaining powder after forming the three-dimensional structure using a sieve mesh;
An airflow classification step of classifying the powder remaining in the sieve net in the sieve net classification step into an airflow classification into a fine particle powder and a coarse particle powder;
A method for regenerating a powder for additive manufacturing, comprising: a mixing step of mixing the fine particle powder, the powder that has passed through the sieve net in the sieve mesh classification step, and a new powder. A sieve mesh classification unit for classifying the remaining powder after forming the three-dimensional structure using a sieve mesh;
An airflow classifying unit for classifying the powder remaining on the sieve net in the sieve mesh classifying unit into a fine particle powder and a coarse particle powder,
An apparatus for reclaiming additive manufacturing powder, comprising: the fine particle powder; a mixing unit that mixes the powder that has passed through the sieve net in the sieve net classification unit; and a new powder. An apparatus for regenerating the additive manufacturing powder according to claim 8;
A molding part for molding a three-dimensional structure by additive modeling;
A powder injection part for injecting the powder produced by the regeneration device into the molding part,
The reproduction apparatus further includes a powder recovery unit that recovers used powder remaining after molding.

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