JP2021003825A - Manufacturing apparatus for three dimensional molded product and manufacturing method for three dimensional molded product - Google Patents

Abstract

To provide a manufacturing apparatus for a three dimensional molded product that can suppress molding defects such as deterioration of molding accuracy and abnormal stop of molding when manufacturing the three dimensional molded product.SOLUTION: A manufacturing apparatus for three dimensional molded product that manufactures a three dimensional molded product by using a resin powder includes: layer forming means for forming a layer containing the resin powder; curing means for curing the layer containing the resin powder; and charging means for charging at least a part of an exposed surface facing the layer containing the resin powder in the manufacturing apparatus for the three dimensional molded product.SELECTED DRAWING: Figure 6

Description

The present invention relates to an apparatus for manufacturing a three-dimensional model and a method for manufacturing a three-dimensional model.

In recent years, equipment for producing a three-dimensional model using resin powder has been used in a wide variety of fields. As an apparatus for producing a three-dimensional model using resin powder, for example, a first layer forming means and a second layer forming means for forming a layer of a three-dimensional modeling composition in a modeling portion where the three-dimensional model is modeled. And, are known (see, for example, Patent Document 1).

An object of the present invention is to provide a three-dimensional model manufacturing apparatus capable of suppressing modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling when manufacturing a three-dimensional model.

The device for producing a three-dimensional model of the present invention as a means for solving this problem is a device for producing a three-dimensional model using resin powder, and forms a layer containing the resin powder. It has a layer forming means, a curing means for curing a layer containing a resin powder, and a charging means for charging at least a part of an exposed surface facing the layer containing the resin powder in a three-dimensional model manufacturing apparatus.

According to the present invention, it is possible to provide a three-dimensional model manufacturing apparatus capable of suppressing modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling when manufacturing a three-dimensional model.

FIG. 1 is a diagram showing an example of a charge distribution in a resin powder. FIG. 2 is a diagram showing another example of charge distribution in the resin powder. FIG. 3 is a diagram showing another example of the charge distribution in the resin powder. FIG. 4 is a diagram showing another example of the charge distribution in the resin powder. FIG. 5 is a diagram showing another example of the charge distribution in the resin powder. FIG. 6 is a schematic view showing an example of an SLS-type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention. FIG. 7 is a schematic view showing another example of the SLS type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention. FIG. 8 is a schematic side view showing another example of the SLS type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention. FIG. 9 is a schematic side view showing another example of the SLS type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention. FIG. 10 is a schematic side view showing an example of a BJ type three-dimensional model manufacturing device as an example of the device for manufacturing a three-dimensional model of the present invention. FIG. 11A is a schematic view showing an example of the flow of modeling of a three-dimensional model in the BJ method. FIG. 11B is a schematic view showing an example of the flow of modeling of a three-dimensional model in the BJ method. FIG. 11C is a schematic view showing an example of the flow of modeling of a three-dimensional model in the BJ method. FIG. 11D is a schematic view showing an example of the flow of modeling of a three-dimensional model in the BJ method. FIG. 11E is a schematic view showing an example of the flow of modeling of a three-dimensional model in the BJ method. FIG. 12 is a schematic side view showing an example of an HSS type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention. FIG. 13A is a schematic view showing an example of the flow of modeling of a three-dimensional model in the HSS method. FIG. 13B is a schematic view showing an example of the flow of modeling of a three-dimensional model in the HSS method. FIG. 14 is a diagram showing an example of the shape of the three-dimensional model manufactured by the three-dimensional model manufacturing apparatus of the present invention.

(Manufacturing equipment for 3D objects, manufacturing method for 3D objects)
The device for producing a three-dimensional model of the present invention is a device for producing a three-dimensional model using resin powder, and is a layer forming means for forming a layer containing the resin powder and a layer containing the resin powder. It has a curing means for curing the resin powder and a charging means for charging at least a part of the exposed surface facing the layer containing the resin powder in the three-dimensional model manufacturing apparatus, and further has other means as needed. ..
The method for producing a three-dimensional model of the present invention is a method for producing a three-dimensional model using resin powder, which comprises a layer forming step of forming a layer containing the resin powder and a layer containing the resin powder. A curing step of curing the resin powder and a charging step of charging at least a part of the exposed surface of the member located opposite to the layer containing the resin powder, which is used in manufacturing the three-dimensional model, are further required. Other steps are included accordingly.

The method for producing a three-dimensional object of the present invention can be suitably performed by the apparatus for producing a three-dimensional object of the present invention, the layer forming step can be preferably performed by the layer forming means, and the curing step is more suitable than the curing means. The charging step can be preferably performed by the charging means, and the other steps can be performed by other means.
Therefore, the details of the method for manufacturing the three-dimensional model of the present invention will be clarified through the description of the device for manufacturing the three-dimensional model of the present invention.

Further, in the three-dimensional model manufacturing apparatus of the present invention, in the conventional three-dimensional model modeling apparatus, deposits formed by adhering resin powder to the layer forming means fall onto the three-dimensional model in the middle of modeling. Therefore, it is based on the finding that it may cause modeling defects.

When a three-dimensional model is formed using resin powder, when a layer containing the resin powder is formed and laminated by a layer forming means such as a recoater, the resin powder soars due to movement of the layer forming means or the like ( There are times when it rolls up. Here, the resin powder is usually in a charged state due to friction between the powders (particles) or the like. In the following, the layer containing the resin powder formed by the layer forming means may be referred to as a “modeling layer”.
In the conventional three-dimensional model manufacturing apparatus, the soaring resin powder adheres to the exposed surface facing the modeling layer in the three-dimensional model manufacturing apparatus, and a deposit of the resin powder is formed on the exposed surface. In some cases. For example, when the exposed surface facing the modeling layer is made of metal that is electrically floating (independent) or grounded (earthed), the exposed surface facing the modeling layer and the charged resin A so-called electric image force (mirror image force) acts as an electrostatic attraction with the powder. In this case or the like, since the exposed surface facing the modeling layer and the soaring resin powder attract each other, deposits of the resin powder are likely to be formed on the exposed surface facing the modeling layer.
Here, in the conventional three-dimensional model manufacturing apparatus, deposits of resin powder are particularly likely to be formed on the surface of a member located near the layer forming means, which is an exposed surface facing the modeling layer.

Further, the deposits of the resin powder formed on the exposed surface facing the modeling layer are formed by, for example, vibration when the layer forming means moves when the forming layers are formed and laminated by the layer forming means. It may fall on a three-dimensional model on the way. The resin powder deposits formed on the exposed surface facing the modeling layer, for example, when the amount of resin powder deposited increases, the weight of the deposits increases, and the deposits spontaneously (spontaneously) peel off from the exposed surface. In some cases, the amount of resin powder deposited increases and the deposit cracks, causing the resin powder to fall naturally.
When the deposit falls on the three-dimensional model in the middle of modeling, the dropped deposit becomes unnecessary protrusions in the three-dimensional model, which may cause modeling defects such as deterioration of modeling accuracy. Furthermore, when the deposit falls on the three-dimensional model in the middle of modeling, the dropped deposit is dragged or caught by the layer forming means, and the modeling of the three-dimensional model stops abnormally. May occur.
As described above, in the conventional three-dimensional model manufacturing apparatus, when the three-dimensional model is manufactured, the deposits due to the resin powder adhering to the exposed surface facing the modeling layer fall, resulting in deterioration of the modeling accuracy. There was a problem that modeling defects such as abnormal stoppage of modeling may occur.

Therefore, the present inventors have diligently studied a three-dimensional model manufacturing apparatus and the like that can suppress modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling when manufacturing a three-dimensional model, and came up with the present invention. did. That is, the present inventors are a three-dimensional model manufacturing apparatus for manufacturing a three-dimensional model using resin powder, and cure the layer forming means for forming the layer containing the resin powder and the layer containing the resin powder. A device for manufacturing a three-dimensional model, which has a curing means and a charging means for charging at least a part of the exposed surface facing the layer containing the resin powder in the device for producing the three-dimensional model, deteriorates the modeling accuracy and causes the modeling. We found that it is possible to suppress modeling defects such as abnormal stoppage.

Here, the resin powder is usually in a charged state.
As an example of the embodiment of the present invention, a case where the charging means charges the exposed surface facing the modeling layer so that the potential in the resin powder and the potential on the exposed surface facing the modeling layer have the same sign will be described. It should be noted that the electric potential in the resin powder and the electric potential in the exposed surface facing the modeling layer have the same sign, for example, both the resin powder and the exposed surface facing the modeling layer are positively charged. In the case, it means that both are negatively charged.
When the electric potential in the resin powder and the electric potential in the exposed surface facing the modeling layer have the same sign, a repulsive force (repulsive force) acts on the resin powder and the exposed surface facing the modeling layer. Therefore, by making the potential on the exposed surface facing the modeling layer the same as the potential on the resin powder, the soaring resin powder approaches the exposed surface facing the modeling layer, and the resin adhering to the exposed surface. The powder can be quickly removed (flicked off). As a result, the three-dimensional model manufacturing apparatus of the present invention can suppress the formation of deposits due to the resin powder on the exposed surface facing the modeling layer, and by extension, the resin powder adhering to the exposed surface facing the modeling layer. It is possible to suppress modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling due to the fall of sediment due to the above.

Subsequently, as another example of the embodiment of the present invention, the charging means charges the exposed surface facing the modeling layer so that the potential in the resin powder and the potential on the exposed surface facing the modeling layer have different signs. The case will be described. The potential of the resin powder and the potential of the exposed surface facing the modeling layer have different signs, for example, when the resin powder is positively charged and the exposed surface facing the modeling layer is negatively charged. Or, it means that the resin powder is negatively charged and the exposed surface facing the modeling layer is positively charged.
When the potential of the resin powder and the potential of the exposed surface facing the modeling layer have different symbols, the resin powder and the exposed surface facing the modeling layer are stronger than when the exposed surface is not charged. Attractive force works. Therefore, by making the potential on the exposed surface facing the modeling layer different from the potential on the resin powder, the deposits of the resin powder adhering to the exposed surface facing the modeling layer move when the layer forming means moves. It is possible to suppress the fall due to the vibration of the plastic. As a result, the three-dimensional model manufacturing apparatus of the present invention can suppress modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling due to the fall of deposits due to the resin powder adhering to the layer forming means.

As described above, in the present invention, the molding accuracy is caused by the falling deposits of the resin powder adhering to the exposed surface facing the modeling layer regardless of the potential relationship between the exposed surface facing the modeling layer and the resin powder. It is possible to suppress modeling defects such as deterioration of the model and abnormal stop of modeling.

<Layer forming means, layer forming process>
The layer forming means is a means for forming a layer containing a resin powder.
The layer forming step is a step of forming a layer containing the resin powder.
The layer forming means is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a mechanism for supplying the resin powder and a mechanism for forming a layer of the resin powder while leveling the supplied resin powder. Examples thereof include a combination of the above, and a known recorder may be used.

<< Resin powder >>
The resin powder means a powder containing a resin component.
The resin powder is not particularly limited and may be appropriately selected depending on the intended purpose.

The average circle-equivalent diameter (average value of the particle size distribution of the circle-equivalent diameter) in the resin powder is preferably 10 μm or more and 150 μm or less, more preferably 20 μm or more and 90 μm or less, and particularly preferably 35 μm or more and 60 μm or less. When the average circle equivalent diameter is 10 μm or more and 150 μm or less, the density, dimensional stability, and surface properties of the obtained three-dimensional model can be improved when the resin powder is stored in a high humidity environment. At the same time, the decrease in strength can be suppressed.
The average circle equivalent diameter can be measured using, for example, a particle image analyzer (device name: FPIA3000, manufactured by Spectris Co., Ltd.).

The equivalent circle diameter can be calculated by, for example, the following formula.
Positive square root of circle equivalent diameter = {4 × (area) ÷ π} It is preferable to calculate the circle equivalent diameter with respect to the projection drawing of each particle. By calculating the average value (number basis) of the circle equivalent diameters thus obtained, the average circle equivalent diameter can be calculated.

The resin powder is a powder with a small amount of fine mixture (fine powder), and the sizes of the main particles constituting the powder are gathered in the range of 30 μm or more and 90 μm or less, and the average value is in the range of 30 μm or more and 90 μm or less. Is preferable.
The median value of the particle size distribution of the equivalent circle diameter is preferably larger than the average equivalent circle diameter (the average value of the particle size distribution of the equivalent circle diameter). When the median value is larger than the diameter equivalent to the average circle, the density, dimensional stability, and surface properties of the obtained three-dimensional model when the resin powder is stored in a high humidity environment can be improved and the strength can be improved. The decrease can be suppressed.

In the particle size distribution of the equivalent circle diameter in the resin powder, if the skirting covers a wide range with respect to the mountain where the particle size distribution is concentrated, the median value is close to the mountain, and the average circle equivalent diameter is affected by the skirting. The position is far from the median because it receives a large amount. In other words, if the median is larger than the average circle equivalent diameter, it indicates that the peaks where the main particle size distributions are concentrated are in large positions, and that the fine powder does not form the major peaks.
On the other hand, if the median is smaller than the average circle equivalent diameter, it indicates that the main peaks are formed by fine powder. Thereby, the particle size distribution of the equivalent circle diameter in the resin powder can be used as an index as to whether the fine powder or the resin powder having a desired size occupies the main part in the number distribution.

Further, the median value of the particle size distribution of the equivalent circle diameter in the resin powder can be measured and calculated using, for example, a wet flow type particle size / shape analyzer (device name: FPIA-3000, manufactured by Sysmex Co., Ltd.). it can. More specifically, for example, a particle shape image was acquired in a state where the number of counts was 3,000 or more, and the equivalent circle diameter of particles having a particle diameter of 0.5 μm or more and 200 μm or less was measured and obtained. The median value can be calculated from the particle size distribution.

The average circularity of the resin powder is preferably 0.75 or more and 0.90 or less, and more preferably 0.75 or more and 0.85 or less. When the average circularity is 0.75 or more and 0.90 or less, the density, dimensional stability, and surface properties of the obtained three-dimensional model when the resin powder is stored in a high humidity environment are improved. At the same time, the decrease in strength can be suppressed.
Here, the circularity is an index showing the circularity, and 1 means that it is the closest to a circle. The circularity is obtained by the following formula when the area (number of pixels) is S and the peripheral length is L.
Circularity = 4πS / L ²

As the average circularity, for example, the circularity of the resin powder can be measured and the arithmetic mean thereof can be used.
When simply determining the circularity, for example, the circularity should be quantified by measuring using a wet flow type particle size / shape analyzer (device name: FPIA-3000, manufactured by Sysmex Corporation). Can be done. This wet flow type particle size / shape analyzer can take a particle image in a suspension flowing in a glass cell at high speed with a CCD (Charge Coupled Device) and analyze each particle image in real time. The number of measurement counts of the particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1,000 or more, and more preferably 3,000 or more.

The shape of the resin powder is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include shapes such as a cylinder, a polygonal prism, and a sphere. Among these, a cylindrical body is preferable.

The columnar body is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a true columnar body and an elliptical columnar body. Among these, a true cylinder is preferable.
The columnar body includes a substantially cylindrical body. Here, the substantially circle means that the ratio of the major axis to the minor axis (major axis / minor axis) is 1 or more and 10 or less. Further, the circular portion of the cylinder may be partially missing.
The polygonal prism is not particularly limited as in the case of the cylinder, and can be appropriately selected depending on the intended purpose, and a part of the polygonal portion of the polygonal prism may be missing.
As with the cylindrical body, the sphere is not particularly limited and may be appropriately selected depending on the intended purpose, and a part of the sphere may be missing.

The diameter of the circular portion of the cylindrical body is not particularly limited and may be appropriately selected depending on the intended purpose. When the circular portion of the cylinder is elliptical, the diameter means the major axis.
The length of one side of the polygonal portion of the polygonal prism is not particularly limited and can be appropriately selected depending on the purpose, but the diameter of the smallest circle (minimum inclusion circle) including all the polygonal portions. Is preferably 5 μm or more and 200 μm or less.
The diameter of the sphere is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 μm or more and 200 μm or less.

The height of the cylinder, that is, the distance between the two opposing circular portions (distance between the upper surface and the bottom surface) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 μm or more and 200 μm or less.
The height of the polygonal prism, that is, the distance between the two opposing polygonal portions (distance between the upper surface and the bottom surface) is not particularly limited as in the height of the cylindrical body, and can be appropriately selected depending on the purpose. However, it is preferably 1 μm or more and 200 μm or less.

The areas of the two opposing circular portions (top and bottom) of the cylinder may be different from each other. However, as the ratio (r2 / r1) of the diameter r2 of the circular portion having the larger area to the diameter r1 of the circular portion having the smaller area, the bulk density can be increased when there is no difference in the areas of the two circular portions. In terms of possible, 1.5 or less is preferable, and 1.1 or less is more preferable.
The areas of the two opposing polygonal portions (top and bottom) in the polygonal prism may be different from each other. However, as the ratio (S2 / S1) of the larger area (S2) of the polygonal portion to the smaller area (S1) of the polygonal portion, the bulk density is higher when there is no difference in the areas of the two polygonal portions. It is preferably close to 1 in that it can be increased.
When modeling a three-dimensional model by the powder bed melt-bonding method, it is possible to improve the modeling accuracy of the three-dimensional model by increasing the bulk density of the resin powder.

The resin powder of a column such as a column or a polygonal column preferably has no vertices in order to increase the bulk density. The apex means a corner portion existing in the pillar body.

The resin component contained in the resin powder is not particularly limited and may be appropriately selected depending on the intended purpose. However, when the resin powder is heated to cure the modeling layer, a thermoplastic resin is preferable. ..

-Thermoplastic resin-
Thermoplastic resin means a resin that plasticizes and melts when heat is applied.
The thermoplastic resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include crystalline resin, non-crystalline resin and liquid crystal resin. As the thermoplastic resin, a crystalline resin is preferable. Further, as the thermoplastic resin, a resin having a large difference between the melting start temperature and the recrystallization temperature at the time of cooling is preferable.
The crystalline resin is a resin in which a melting point peak is detected in a measurement based on ISO3146 (plastic transition temperature measuring method, JIS K7121).

Examples of the thermoplastic resin include polyolefin, polyamide, polyester, polyether, polyphenylene sulfide, polyacetal (POM: Polyoxymethylene), polyimide, fluororesin and the like. These may be used alone or in combination of two or more.

Examples of the polyolefin include polyethylene (PE) and polypropylene (PP).

Examples of the polyamide include polyamide 410 (PA410), polyamide 6 (PA6), polyamide 66 (PA66), polyamide 610 (PA610), polyamide 612 (PA612), polyamide 11 (PA11), and polyamide 12 (PA12); Examples thereof include semi-aromatic polyamides such as polyamide 4T (PA4T), polyamide MXD6 (PAMXD6), polyamide 6T (PA6T), polyamide 9T (PA9T), and polyamide 10T (PA10T).

Examples of the polyester include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polylactic acid (PLA) and the like. Among these, those having an aromatic component containing terephthalic acid or isophthalic acid as a part are preferable in terms of imparting heat resistance.

Examples of the polyether include polyaryl ketone and polyether sulfone.
Examples of the polyarylketone include polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketone ketone (PEKK), polyaryletherketone (PAEK), polyetheretherketone ketone (PEEKK), and polyether. Examples thereof include ketone ether ketone ketone (PEKEKK).

The thermoplastic resin may have two melting point peaks, for example, PA9T. A thermoplastic resin having two melting point peaks melts completely when the temperature becomes higher than the melting point peak on the high temperature side.

Further, polyphthalamides, polyphenylene sulfides, liquid crystal polymers, polysulfones, polyethersulfones, polyetherimides, polyamideimides, polyetheretherketones, polytetrafluoroethylene and the like are referred to as "super engineering plastics".
The thermoplastic resin is preferably at least one selected from super engineering plastics when a three-dimensional model is produced by the HSS (High Speed Sintering) method. When the thermoplastic resin is a super engineering plastic, the tensile strength, heat resistance, chemical resistance, and flame retardancy of the three-dimensional model to be modeled can be improved, and the three-dimensional model can be used for industrial purposes. It is advantageous in that.

Examples of the resin powder include, in addition to thermoplastic resins, resin powders made of non-crystalline resins, additives such as reinforcing agents, flame retardant agents, plasticizers, stabilizers, antioxidants, and crystal nucleating agents. May include. These may be used alone or in combination of two or more. These may be mixed with a thermoplastic resin and embedded in the resin powder, or may be adhered to the surface of the resin powder.

The resin powder is preferably a resin having a melting point of 100 ° C. or higher as measured in accordance with ISO 3146. Here, the melting point of the resin powder can be measured by using differential scanning calorimetry (DSC) in accordance with ISO 3146 (Plastic transition temperature measuring method, JIS K7121), and when a plurality of melting points are present, the melting point can be measured. , The melting point on the high temperature side can be used.

<< Average charging potential in resin powder >>
Here, a method of measuring the electric potential in the resin powder will be described.
Usually, the resin powder is considered to have a different charge amount (potential) for each individual particle in the resin powder. Therefore, when measuring the potential of the resin powder, for example, it is preferable to measure the charge amount of each particle in the resin powder and obtain the charge distribution in the resin powder from the frequency of the measured charge amount.
Further, in the present invention, for example, it is preferable to calculate the average charging potential of the resin powder based on the obtained charge distribution. Here, as the average charging potential of the resin powder, for example, the arithmetic mean of the charging distribution in the resin powder, the mode value of the charging distribution, the median value of the charging distribution, and the like can be used.

The amount of charge for each individual particle in the resin powder can be measured using, for example, E-SPART Analyzer EST-G (manufactured by Hosokawa Micron Co., Ltd.). It should be noted that E-SPART Analyzer EST-G can be used to measure the particle size of the resin powder as well as the amount of charge for each individual particle in the resin powder.
Further, by E-SPART Analyzer EST-G, the charge distribution in the resin powder can be obtained from the charge amount of each particle in the measured resin powder.

Here, FIG. 1 shows an example of the charge distribution in the resin powder. The example of FIG. 1 is an example of the charge distribution in the case where the ratio of the positively (positively) charged particles and the negatively (negatively) charged particles are 50% each in the resin powder. .. In the example shown in FIG. 1, for example, the average charging potential of the resin powder is “0”. In the following, the ratio of positively charged particles in the resin powder may be referred to as "positively charged distribution ratio".
FIG. 2 shows another example of the charge distribution in the resin powder. The example of FIG. 2 is an example of the charge distribution when all the particles are negatively charged in the resin powder. In the example shown in FIG. 2, for example, the average charging potential of the resin powder has a negative value.
Further, FIG. 3 shows another example of the charge distribution in the resin powder. The example of FIG. 3 is an example of the charge distribution when all the particles are positively charged in the resin powder. In the example shown in FIG. 3, for example, the average charging potential of the resin powder is a positive value.

Further, FIG. 4 shows another example of the charge distribution in the resin powder. The example of FIG. 4 is an example of the charge distribution in the case where the ratio of positively charged particles is 10% and the ratio of negatively charged particles is 90% in the resin powder. In the example shown in FIG. 4, for example, the average charging potential of the resin powder has a negative value.
In addition, FIG. 5 shows another example of the charge distribution in the resin powder. The example of FIG. 5 is an example of the charge distribution in the case where the ratio of positively charged particles is 90% and the ratio of negatively charged particles is 10% in the resin powder. In the example shown in FIG. 5, for example, the average charging potential of the resin powder is a positive value.

<< Layer containing resin powder (modeling layer) >>
The layer containing the resin powder is not particularly limited and may be appropriately selected depending on the intended purpose. In the following, the layer containing the resin powder formed by the layer forming means may be referred to as a “modeling layer”. Further, in the present specification, forming a modeling layer by the layer forming means may be referred to as "forming", and producing a three-dimensional model by curing and laminating the modeling layer may be referred to as "modeling". ..

The average thickness of the modeling layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 μm or more and 100 μm or less.

<Curing means, curing process>
The curing means is a means for curing a layer (modeling layer) containing a resin powder.
The curing step is a step of curing a layer (modeling layer) containing resin powder.
The curing means is not particularly limited and may be appropriately selected depending on the intended purpose. The curing means can be selected, for example, according to the manufacturing method in the manufacturing apparatus for the three-dimensional model.

Here, the manufacturing method in the manufacturing apparatus for a three-dimensional object is not particularly limited as long as it uses a resin powder (powder laminating method), and can be appropriately selected according to the purpose. For example, a powder bed. Examples thereof include a melting (PBF: powdered fusion) method and a binder jetting (BJ: binder jetting).

Examples of the PBF method include an SLS (selective laser sintering) method, an SMS (selective mask sintering) method, and the like.
An HSS (High Speed Sintering) method and the like can be mentioned.
The SLS method is a method of modeling a three-dimensional model by repeatedly irradiating a laser and fusing the resin powders in the modeling layer to each other.
The SMS method is a method in which a three-dimensional model is formed by repeatedly fusing resin powders in a modeling layer by irradiating a laser on a flat surface with a mask.
In the HSS method, a three-dimensional model is formed by repeatedly discharging a modeling solution containing a radiant energy absorber into a predetermined region of the modeling layer and then applying radiant energy to fuse the resin powders together. It is a method to do.

Therefore, when the manufacturing method in the three-dimensional model manufacturing apparatus is the SLS method or the SMS method, the curing means can be, for example, an electromagnetic wave irradiation means for irradiating an electromagnetic wave.
The electromagnetic wave irradiation means is not particularly limited and may be appropriately selected according to the purpose. For example, a laser that irradiates ultraviolet rays, visible rays, infrared rays, etc., microwaves, discharges, electron beams, radiant heaters, LEDs Examples include lamps, halogen lamps, or combinations thereof.

Here, when the manufacturing method in the three-dimensional model manufacturing apparatus is the SMS method, for example, the technique described in US Pat. No. 6,531,086 can be preferably used.
In the SMS method, for example, a shielding mask is used to selectively block infrared radiation, and a part of the powder layer is selectively irradiated. Further, in the SMS method, a material that enhances the infrared absorption characteristics of the resin powder may be contained. Examples of the material for enhancing the infrared absorption property of the resin powder include a heat absorber and a dark-colored substance (carbon fiber, carbon black, carbon nanotube, carbon fiber, cellulose nanofiber, etc.).

When the manufacturing method in the three-dimensional model manufacturing apparatus is the HSS method, the curing means is, for example, a discharging means for discharging a modeling solution containing a radiant energy absorber to the modeling layer and an electromagnetic wave irradiation for irradiating electromagnetic waves. It can be a combination of means.
The ejection means is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an inkjet head. Examples of the modeling solution (model material) containing the radiant energy absorber discharged by the ejection means include ink containing a black pigment such as carbon black, ink containing a pigment, and ink containing metal fine particles.
As the electromagnetic wave irradiation means, for example, the same electromagnetic wave irradiation means as in the SLS method or the SMS method can be used, but a halogen lamp is preferable.

Here, the BJ method is a method of molding a three-dimensional model by repeatedly discharging an adhesive to the resin powder in the modeling layer by a discharge means and adhering the resin powders to each other.
As the ejection means, for example, an inkjet head or the like can be used as in the case of the HSS method. The adhesive discharged by the discharge means is not particularly limited as long as the resin powders can be bonded (bonded) to each other, and can be appropriately selected depending on the purpose. For example, a solution containing an adhesive component can be mentioned. Be done. Here, the adhesive component may be contained in a state of being dissolved in the solution to be discharged, or may be mixed as adhesive particles in the resin powder. The adhesive component is preferably dissolved in the solution to be discharged. For example, if the solution to be discharged is mainly composed of water, the adhesive component is preferably water-soluble.

Examples of the adhesive component include polyvinyl alcohol (PVA), polyvinylpyrrolidone, polyamide, polyacrylamide, polyethyleneimine, polyethylene oxide, polyacrylic acid resin, cellulose resin, gelatin and the like. Among these, polyvinyl alcohol is preferable in order to increase the strength and dimensional accuracy of the three-dimensional model.

<Charging means, charging process>
The charging means is a means for charging at least a part of the exposed surface facing the layer (modeling layer) containing the resin powder in the three-dimensional model manufacturing apparatus.
The charging step is a step of charging at least a part of the exposed surface facing the layer (modeling layer) containing the resin powder in the manufacturing apparatus for manufacturing the three-dimensional modeled object.
In the present invention, charging at least a part of the exposed surface facing the modeling layer means that, for example, at least a part of the exposed surface facing the modeling layer has a potential other than 0V (a potential larger than 0V or a potential higher than 0V). It means to have a small potential). In other words, in the present invention, charging at least a part of the exposed surface facing the modeling layer means that, for example, at least a part of the exposed surface facing the modeling layer has a desired potential bias. means.

Here, the charging means is not particularly limited as long as it can charge at least a part of the exposed surface facing the modeling layer, and can be appropriately selected depending on the intended purpose. For example, a voltage is applied. Examples thereof include possible voltage applying means, static electricity applying means capable of generating static electricity on an object by corona discharge, and the like.
Among these, the voltage applying means is preferable as the charging means. In other words, it is preferable that the charging means charges the exposed surface by applying a voltage to the exposed surface facing the modeling layer. By doing so, for example, in the present invention, the exposed surface facing the molding layer can be more stably set to a desired potential, so that the molding accuracy is deteriorated due to the fall of the resin powder deposits. It is possible to more reliably suppress modeling defects such as abnormal stoppage of modeling. In the present specification, "at least a part of the exposed surface facing the modeling layer" may be simply referred to as "exposed surface facing the modeling layer", and "exposed surface facing the modeling layer" is referred to as "exposed surface facing the modeling layer". It does not necessarily mean "the entire exposed surface facing the modeling layer".
The voltage applying means is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a known power supply device or the like can be used.

Here, the potential of the exposed surface when charging the exposed surface facing the modeling layer by the charging means may be positive (positive) or negative (negative). As described above, in the present invention, the deposits of the resin powder adhering to the exposed surface facing the modeling layer fall regardless of the potential relationship between the exposed surface facing the modeling layer and the resin powder. It is possible to suppress modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling.

Further, the potential of the exposed surface when charging the exposed surface facing the modeling layer by the charging means preferably has the same sign as the average charging potential of the resin powder. That is, it is preferable that the potential on the exposed surface facing the modeling layer has the same sign as the average charging potential of the resin powder.
By doing so, in the three-dimensional model manufacturing apparatus of the present invention, for example, for more particles in the resin powder, the soared resin powder approaches the exposed surface facing the modeling layer and adheres to the exposed surface. The resin powder can be quickly removed (flicked off). As a result, the three-dimensional model manufacturing apparatus of the present invention can further suppress the formation of deposits due to the resin powder on the exposed surface facing the modeling layer, and by extension, the resin adhering to the exposed surface facing the modeling layer. It is possible to more reliably suppress modeling defects such as deterioration of modeling accuracy and abnormal stoppage of modeling due to the fall of powder deposits.

When the potential of the exposed surface facing the modeling layer has a different sign from the average charging potential of the resin powder, for example, other than the upper surface of the region (hardened region) in which the three-dimensional model is formed in the modeling layer. In this region, the potential of the exposed surface facing the modeling layer may be switched to the same sign as the average charging potential of the resin powder.

When the voltage applying means is used as the charging means, the voltage applied by the voltage applying means may be a voltage having a constant magnitude or may be changed in a predetermined cycle. In other words, the charging means may apply a voltage so that the potential on the exposed surface facing the modeling layer becomes constant, or may apply a voltage so as to change at a predetermined cycle. In other words, the voltage applied by the voltage applying means may be, for example, a direct current potential or an alternating (alternating current) potential. The predetermined cycle is not particularly limited and may be appropriately selected depending on the purpose.
Further, when the voltage applying means is used as the charging means, it is preferable that the charging means applies a voltage so that the sign of the potential on the exposed surface facing the modeling layer changes. As a result, the three-dimensional model manufacturing apparatus of the present invention can be used as a modeling layer even when the ratio of positively charged particles and negatively charged particles in the resin powder is 50% each. It is possible to more reliably suppress the formation of deposits due to the resin powder on the facing exposed surfaces. For this reason, the three-dimensional model manufacturing apparatus of the present invention is more susceptible to modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling due to the fall of deposits due to resin powder adhering to the exposed surface facing the modeling layer. It can be surely suppressed.

The potential on the exposed surface facing the modeling layer is not particularly limited as long as it is other than 0V, and can be appropriately selected depending on the intended purpose, but is preferably -100V or more and 100V or less. When the potential of the exposed surface facing the modeling layer is -100V or more and 100V or less, the three-dimensional model manufacturing apparatus of the present invention can suppress the generation of leak current, and the exposed surface facing the modeling layer. It is possible to more stably suppress the formation of deposits due to the resin powder.

<< Exposed surface facing the modeling layer >>
Here, an exposed surface facing the modeling layer in a manufacturing apparatus for manufacturing a three-dimensional model (a manufacturing apparatus for a three-dimensional model) will be described.
The exposed surface facing the modeling layer is exposed facing the modeling layer, which is a layer of resin powder, in a three-dimensional model manufacturing apparatus, and the resin powder soared during modeling of the three-dimensional model adheres to the exposed surface. It means a possible surface.
Further, the shape of the exposed surface facing the modeling layer is not particularly limited and can be appropriately selected according to the purpose, and is not limited to a linear planar shape, for example, a surface including a curved surface or unevenness. And so on. Further, "facing the modeling layer" is not limited to facing the modeling layer in parallel, and may be, for example, facing at least a part of the modeling layer.
In the present invention, at least a part of the exposed surface facing the modeling layer in the three-dimensional model manufacturing apparatus is charged by the charging means.

At least a part of the exposed surface facing the modeling layer is not particularly limited and may be appropriately selected depending on the purpose. For example, an exposed surface in the layer forming means facing the modeling layer and a three-dimensional modeled object in the modeling layer are modeled. The upper surface of the region (area to be cured) and the like can be mentioned. Among these, it is preferable that it is an exposed surface in the layer forming means facing the shape layer. In other words, it is preferable that at least a part of the exposed surface facing the modeling layer to be charged by the charging means is the exposed surface in the layer forming means facing the modeling layer. By doing so, the modeling apparatus for the three-dimensional model of the present invention can suppress the formation of the resin powder deposits on the layer forming means and the members located in the vicinity of the layer forming means. Therefore, the modeling apparatus for the three-dimensional model of the present invention can more reliably suppress modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling due to the fall of deposits due to resin powder.
In the present invention, a form in which the entire layer forming means is charged is also preferable.

When at least a part of the potential of the layer forming means has a different sign from the average charging potential of the resin powder, for example, other than the upper surface of the region (hardened region) in which the three-dimensional model is formed in the modeling layer. When the layer forming means is located in the region, the potential of the exposed surface facing the modeling layer may be switched to the same sign as the average charging potential of the resin powder. By doing so, it is possible to selectively drop the resin powder deposits in a region that does not directly affect the production of the three-dimensional model, and prevent the deposits from falling onto the three-dimensional model in the middle of modeling.

When a voltage applying means is used as the charging means, at least a part of the exposed surface facing the modeling layer to be charged by the charging means is preferably formed of a conductor, more preferably made of metal. In the present invention, for example, by forming at least a part of the exposed surface facing the modeling layer with metal, the exposed surface can be charged more easily.

<Other means>
The other means are not particularly limited and may be appropriately selected depending on the intended purpose. For example, a maintenance means for suppressing the occurrence of discharge defects in the discharge means, which is an example of the curing means, and a three-dimensional model manufacturing apparatus. A control means for controlling the control can be mentioned.

The three-dimensional model manufacturing apparatus of the present invention can manufacture (model) a three-dimensional model by repeatedly operating at least the layer forming means and the curing means. Similarly, in the method for producing a three-dimensional model of the present invention, at least the layer forming step and the curing step can be repeated to produce (model) the three-dimensional model.
Further, when manufacturing a three-dimensional model, the charging means may be operated repeatedly or only once. Similarly, when manufacturing a three-dimensional model, the charging step may be repeated or may be operated only once.

Further, the shape of the three-dimensional model to be manufactured by the apparatus for manufacturing the three-dimensional model of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. The shape of the three-dimensional model manufactured by the three-dimensional model manufacturing apparatus of the present invention can be, for example, the shape shown in FIG.

[Embodiment 1-1]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 6 is a schematic view showing an example of an SLS-type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention.
In the example shown in FIG. 6, the three-dimensional model manufacturing apparatus 100a stores the resin powder in the supply tank 5, and supplies the resin powder to the laser scanning space 6 by using the rollers 4 according to the amount of the resin powder used. To do. The temperature of the supply tank 5 is preferably controlled by the heater 3.
Subsequently, the three-dimensional object manufacturing apparatus 100a irradiates the laser scanning space 6 with the laser light output from the electromagnetic irradiation source 1 which is an example of the curing means by using the reflector 2. The resin powder can be sintered by the heat generated by the laser beam to obtain a three-dimensional model.
Here, in the example shown in FIG. 6, a direct current potential is applied to the roller 4, which is an example of the layer forming means, by the voltage applying means 9a, which is an example of the charging means, and the roller 4 is in a charged state. ing. For this reason, in the example of the three-dimensional model manufacturing apparatus shown in FIG. 6, the deposits due to the resin powder adhering to the roller 4 and the members in the vicinity thereof fall, resulting in deterioration of modeling accuracy and abnormal stoppage of modeling. Molding defects can be suppressed.

The temperature of the supply tank 5 is preferably 10 ° C. or higher lower than the melting point of the resin powder.
The component floor temperature in the laser scanning space 6 is preferably 5 ° C. or higher lower than the melting point of the resin powder.
The laser output of the electromagnetic irradiation source 1 is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 watts or more and 150 watts or less.

[Embodiment 1-2]
FIG. 7 is a schematic view showing another example of the SLS type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention.
Here, in the example shown in FIG. 7, unlike the example shown in FIG. 6, the three-dimensional model manufacturing apparatus 100b uses the voltage applying means 9b, which is an example of the charging means, on the roller 4, which is an example of the layer forming means. , Alternate voltage (alternative potential) is applied, and the roller 4 is in a charged state. For this reason, in the example of the three-dimensional model manufacturing apparatus shown in FIG. 7, the deposits due to the resin powder adhering to the roller 4 and the members in the vicinity thereof fall, resulting in deterioration of modeling accuracy and abnormal stoppage of modeling. Molding defects can be suppressed.

[Embodiment 1-3]
FIG. 8 is a schematic side view showing another example of the SLS type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention.
In the example shown in FIG. 8, the top plate in the chamber 7 filled with the rollers 4, the peripheral members 4a of the rollers 4, and the N ₂ (nitrogen) gas, which are examples of the exposed surfaces facing the modeling layer by the voltage applying means 9b. 7a, an alternating voltage is applied to the swing gate 8 between the storage tank (feed tank) 5 and the laser scanning space (part tank) 6. In the example shown in FIG. 8, the laser beam 100c of the three-dimensional model manufacturing apparatus is irradiated from the electromagnetic irradiation source (laser light source) 1 and reflected by the reflector (for example, galvano mirror) 2. The laser scanning space 6 is irradiated through the lens 2a.
In the example of the modeling apparatus for the three-dimensional model shown in FIG. 8, the members other than the roller 4 located on the exposed surface facing the modeling layer are also in a charged state. By doing so, in the example of the modeling apparatus for the three-dimensional model shown in FIG. 8, the deposits due to the resin powder adhering to the member having the exposed surface facing the modeling layer fall, resulting in deterioration of modeling accuracy and modeling. It is possible to suppress modeling defects such as abnormal stop.

FIG. 9 is a schematic side view showing another example of the SLS type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention.
In the example shown in FIG. 9, unlike the example shown in FIG. 8, in the three-dimensional model manufacturing apparatus 100d, an alternating voltage is applied to the roller 4 and the peripheral member 4a of the roller 4 by the voltage applying means 9b. , The roller 4 and the peripheral member 4a of the roller 4 are in a charged state. For this reason, in the example of the three-dimensional model manufacturing apparatus shown in FIG. 9, the deposits due to the resin powder adhering to the rollers 4 and the peripheral members 4a of the rollers 4 fall, resulting in deterioration of modeling accuracy and abnormal stop of modeling. It is possible to suppress modeling defects such as.

[Embodiment 2]
FIG. 10 is a schematic side view showing an example of a BJ type three-dimensional model manufacturing device as an example of the device for manufacturing a three-dimensional model of the present invention.
In the example of FIG. 10, in the three-dimensional model manufacturing apparatus, the modeling portion 30 in which the modeling layer 31 formed of the resin powder is cured (adhered) is formed, and the modeling layer 31 is used as the modeling liquid 10. It is provided with a discharge head 52 as a discharge means for discharging the adhesive.

In the example of FIG. 10, the three-dimensional model manufacturing apparatus includes a flattening roller 12 and the like, which is an example of layer forming means (flattening member, recorder). The flattening member may be, for example, a plate-shaped member (blade) instead of the rotating body.

Further, in the example of FIG. 10, the three-dimensional model manufacturing apparatus includes a supply tank 21 for supplying the resin powder 20, a modeling tank 22 in which the modeling layer 31 is laminated to form the three-dimensional model, and a surplus powder receiving tank. It has 25 and. The resin powder 20 is supplied to the supply tank 21 before modeling. The bottom of the supply tank 21 can be raised and lowered in the vertical direction (height direction) as the supply stage 23. Similarly, the bottom of the modeling tank 22 can be raised and lowered in the vertical direction (height direction) as the modeling stage 24. A three-dimensional model in which the cured portion 30 is laminated on the modeling stage 24 is modeled.

The side surface of the supply stage 23 is arranged so as to be in contact with the inner side surface of the supply tank 21. The side surface of the modeling stage 24 is arranged so as to be in contact with the inner surface surface of the modeling tank 22. The upper surfaces of the supply stage 23 and the modeling stage 24 are kept horizontal.

The flattening roller 12 supplies the resin powder 20 supplied on the supply stage 23 of the supply tank 21 to the modeling tank 22, and flattens the modeling layer 31 by the flattening roller 12 which is a flattening member. Form.
The flattening roller 12 is arranged so as to be reciprocally movable relative to the stage surface in the arrow Y direction along the stage surface (the surface on which the resin powder 20 is loaded) of the modeling stage 24, and is arranged by the reciprocating movement mechanism. Will be moved. Further, the flattening roller 12 is rotationally driven by a motor.

The flattening roller 12 transfers and supplies the resin powder 20 from the supply tank 21 to the modeling tank 22 and flattens the surface by leveling the surface to form a modeling layer 31 which is a layered particle having a predetermined thickness.
The flattening roller 12 is a rod-shaped member longer than the inner dimensions of the modeling tank 22 and the supply tank 21 (that is, the width of the portion where the resin powder 20 is provided or the portion where the resin powder 20 is charged), and is staged by a reciprocating moving mechanism. It is reciprocated in the Y direction (secondary scanning direction) along the surface.
The flattening roller 12 moves horizontally while being rotated by a motor so as to pass above the supply tank 21 and the modeling tank 22 from the outside of the supply tank 21. As a result, the resin powder 20 is transferred and supplied onto the modeling tank 22, and the modeling layer 31 is formed by flattening the resin powder 20 while the flattening roller 12 passes over the modeling tank 22.

Further, a particle removing plate 13 which is a particle removing member for removing the resin powder 20 adhering to the flattening roller 12 in contact with the peripheral surface of the flattening roller 12 is arranged.
The particle removing plate 13 moves together with the flattening roller 12 in contact with the peripheral surface of the flattening roller 12. Further, the particle removing plate 13 can be arranged in the forward direction even in the counter direction when the flattening roller 12 rotates in the rotation direction when flattening.

Further, in the example shown in FIG. 10, a voltage is applied to the flattening roller 12 which is an example of the layer forming means by the voltage applying means which is an example of the charging means, and the flattening roller 12 is charged. It has become. For this reason, in the example of the three-dimensional model manufacturing apparatus shown in FIG. 10, the deposits due to the resin powder adhering to the flattening roller 12 and the members in the vicinity thereof fall, resulting in deterioration of modeling accuracy and abnormal stop of modeling. It is possible to suppress modeling defects such as.

The discharge head 52 has a plurality of rows of nozzles in which a plurality of nozzles for discharging liquid are arranged. The head 52 nozzle row discharges the adhesive as the modeling liquid 10. Further, the head 52 can also discharge colored modeling liquids such as cyan, magenta, yellow, and black. The head 52 is not limited to this.

In the present embodiment, the particle tank 11 of the modeling unit 1 has three tanks, a supply tank 21, a modeling tank 22, and a surplus powder receiving tank 25, but the modeling tank is not provided. The resin powder 20 may be supplied to 22 from the powder supply device and flattened by the flattening roller 12.

Next, the flow of manufacturing (modeling) of the three-dimensional modeled object in the BJ method will be described with reference to FIGS. 11A to 11E. 11A to 11E are schematic views showing an example of the flow of modeling of a three-dimensional model in the BJ method.
The first layer of the cured portion 30 will be described from the state where the first-layer cured portion 30 is formed on the modeling stage 24 of the modeling tank 22.
When the next cured portion 30 is formed on the cured portion 30, as shown in FIG. 11A, the supply stage 23 of the supply tank 21 is raised in the Z1 direction, and the modeling stage 24 of the modeling tank 22 is lowered in the Z2 direction.

At this time, the lowering distance of the modeling stage 24 is set so that the distance between the upper surface of the modeling tank 22 (the surface of the modeling layer) and the lower portion of the flattening roller 12 (lower tangential portion) is Δt. This interval Δt corresponds to the thickness of the modeling layer 31 to be formed next. The interval Δt is preferably about several tens to 100 μm.

Next, as shown in FIG. 11B, the particles 20 located above the upper surface level of the supply tank 21 are moved in the Y2 direction (modeling tank 22 side) while rotating the flattening roller 12 in the forward direction (arrow direction). By doing so, the resin powder 20 is transferred and supplied to the modeling tank 22 (particle supply).

Further, as shown in FIG. 11C, the flattening roller 12 is moved in parallel with the stage surface of the modeling stage 24 of the modeling tank 22, and as shown in FIG. 11D, a predetermined thickness is formed on the hardened portion 30 of the modeling stage 24. The modeling layer 31 having Δt is formed (flattening). After forming the modeling layer 31, the flattening roller 12 is moved in the Y1 direction and returned to the initial position as shown in FIG. 11D.

Here, the flattening roller 12 can move while keeping a constant distance from the upper surface level of the modeling tank 22 and the supply tank 21. By being able to move while being kept constant, the flattening roller 12 conveys the resin powder 20 onto the modeling tank 22, and the modeling layer having a uniform thickness Δt is placed on the modeling tank 22 or the already formed hardened portion 30. 31 can be formed.

After that, as shown in FIG. 11E, droplets of the adhesive as the modeling liquid 10 are discharged from the discharge head 52 to a desired position in the modeling tank 22 to form a new cured portion 30.

Next, a three-dimensional model is manufactured by repeating the process of forming the modeling layer 31 by supplying and flattening the resin powder and the process of discharging the modeling liquid by the discharge head 52 to repeat the modeling of the new cured portion 30 as many times as necessary. ..

Further, in the examples shown in FIGS. 11A to 11E, a voltage is applied to the flattening roller 12 which is an example of the layer forming means by the voltage applying means which is an example of the charging means, and the flattening roller 12 is charged. It is in a state. Therefore, in the example of the three-dimensional model manufacturing apparatus shown in FIGS. 11A to 11E, when the three-dimensional model is manufactured, the deposits due to the resin powder adhering to the flattening roller 12 and the members in the vicinity thereof fall. As a result, it is possible to suppress modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling.

[Embodiment 3]
FIG. 12 is a schematic side view showing an example of an HSS type three-dimensional model manufacturing apparatus as an example of the three-dimensional model manufacturing apparatus of the present invention.
In the example shown in FIG. 12, unlike the example shown in FIG. 10, a light irradiation unit 80 as an electromagnetic wave irradiation means for irradiating the modeling layer 31 with light is added to the discharge head 52. Further, in the example shown in FIG. 12, unlike the example shown in FIG. 10, the discharge head 52 discharges a model material (for example, black ink) as the modeling liquid 10. The configuration of the other devices is the same as that of the BJ-type three-dimensional model manufacturing device shown in FIG.

Next, the flow of manufacturing (modeling) of the three-dimensional model in the HSS method will be described with reference to FIGS. 13A and 13B. In the flow of manufacturing the three-dimensional model in the HSS method, the process of forming the model layer 31 having a uniform thickness Δt on the already formed cured portion 30 is the BJ method shown in FIGS. 11A to 11D. Since it is the same as the flow of manufacturing a three-dimensional model, the description thereof will be omitted.

As shown in FIG. 13A, droplets of the model material as the modeling liquid 10 are discharged from the discharge head 52 to a desired position in the modeling tank 22 to form a model region to be a cured portion. Then, as shown in FIG. 13B, the light irradiation unit 80 scans the modeling tank 22 while irradiating the light 81 to heat the resin powder 20 and fuse the resin powders to each other to form the cured portion 30. To do.

Next, a new cured portion 30 is formed by repeating a step of forming the molding layer 31 by supplying and flattening the resin particles, a molding liquid discharging step by the head 52, and a curing step by the light irradiation unit 80. At this time, the new cured portion 30 and the cured portion 30 in the lower layer thereof are integrated into a part of the three-dimensional model.
After that, the three-dimensional model is manufactured by repeating the process of forming the modeling layer 31 by supplying and flattening the resin particles, the process of discharging the modeling liquid by the head 52, and the curing process by the light irradiation unit 80 as many times as necessary.

Further, in the examples shown in FIGS. 13A to 13B, a voltage is applied to the flattening roller 12 which is an example of the layer forming means by the voltage applying means which is an example of the charging means, and the flattening roller 12 is charged. It is in a state. Therefore, in the example of the three-dimensional model manufacturing apparatus shown in FIGS. 13A to 13B, when the three-dimensional model is manufactured, the deposits due to the resin powder adhering to the flattening roller 12 and the members in the vicinity thereof fall. As a result, it is possible to suppress modeling defects such as deterioration of modeling accuracy and abnormal stop of modeling.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Example 1)
First, a polybutylene terephthalate (PBT) resin (trade name: Novaduran 5020, manufactured by Mitsubishi Engineering Plastics Co., Ltd., melting point: 218 ° C, glass transition temperature: 43 ° C) is used in an extrusion processing machine (manufactured by Nippon Steel Co., Ltd.). The mixture was stirred at a temperature 30 ° C. higher than the melting point. Next, the stirred PBT resin was stretched into a fibrous form using a resin having a circular nozzle hole. The number of threads coming out of the nozzle was 60.
Then, after further stretching about twice to make a fiber having an accuracy of ± 4 μm at a fiber diameter of 55 μm, a push-cutting type cutting device (manufactured by Ogino Seiki Seisakusho Co., Ltd., NJ series 1200 type) is used to aim at a length of 55 μm. It was cut to obtain a resin powder 1 having a substantially cylindrical body.

When the cross section of the resin powder 1 after cutting was confirmed using a scanning electron microscope (device name: S4200, manufactured by Hitachi, Ltd.) at a magnification of 300 times, the cross sections were cut cleanly and the cut surfaces were mutually cut. It was parallel. Moreover, when the height of the resin powder 1 of the substantially cylindrical body was measured, it was possible to cut with an accuracy of 55 μm ± 10 μm.
The obtained resin powder 1 was passed through a sieve having an opening of 125 μm to remove coarse particles such as partial cutting defects.

Further, the resin powder 1 was stored in an environment of 27 ° C. and 80% humidity for 1 week. Using the resin powder 1 stored for one week, a modified machine was used to modify the SLS method three-dimensional model manufacturing equipment (EOS, P 770) so that a voltage could be applied to the recorder as a layer forming means. , The superficial sample 1 as a three-dimensional model was modeled. The surface sample was a rectangular parallelepiped having a side of 50 mm and an average thickness of 5 mm.
The setting conditions were that the average thickness of the modeling layer was 0.1 mm, the laser output was 10 watts or more and 150 watts or less, the laser scanning space was 0.1 mm, and the floor temperature was set to -3 ° C. from the melting point of the resin.

Here, HJPM-5R1.2-SP (manufactured by Matsusada Precision Co., Ltd.) was used as a charging means for applying a voltage to the recorder in the SLS type three-dimensional modeling apparatus (manufactured by EOS, modified machine of P770). ..
In Example 1, a voltage was applied so that the potential of the recorder was 90 V.

Further, the proportion of positively charged particles (positively charged distribution ratio) in the resin powder 1 was measured using E-SPART Analyzer EST-G (manufactured by Hosokawa Micron Co., Ltd.) and found to be 12%. Moreover, when the average charge potential in the resin powder 1 was calculated based on the measurement result of E-SPART Analyzer EST-G, it was a negative value.

<Surface (orange peel)>
Using the three-dimensional modeled sample, the surface was visually observed, observed with an optical microscope, and a sensory test was performed. In the sensory test, the sample was touched by hand, and the surface texture, especially smoothness, was evaluated from the tactile sensation. These results were combined and the surface property (orange peel property) was evaluated based on the evaluation criteria.
(Evaluation criteria)
⊚: The surface is very smooth, and there are almost no worrisome irregularities or rough surfaces. ○: There is no problem with the smoothness of the surface, and irregularities and rough surfaces on the surface are acceptable. △: The surface is not smooth. Unevenness and rough surface can be visually recognized ×: The surface is caught, and many defects such as unevenness and distortion of the surface are recognized.

Table 1 shows the types of the resin powder, the potential applied to the recoater (recoater applied potential), the positive charge distribution ratio in the resin powder, and the evaluation results of the surface property in Example 1.

(Example 2)
In Example 1, a surface sample was formed, a surface sample 2 was formed, and the same as in Example 1 except that a voltage was applied so that the potential of the recorder was 50 V. The surface quality was evaluated.
Table 1 shows the evaluation results of the type of resin powder, the potential for applying the recoater, the positive charge distribution ratio in the resin powder, and the surface property in Example 2.

(Example 3)
In Example 1, a surface sample was formed, a surface sample 3 was formed, and the surface sample 3 was formed in the same manner as in Example 1 except that a voltage was applied so that the potential of the recorder was −90 V. The surface property was evaluated in the same manner.
Table 1 shows the evaluation results of the type of resin powder, the potential applied to the recoater, the positive charge distribution ratio in the resin powder, and the surface property in Example 3.

(Example 4)
In Example 1, a surface sample was formed in the same manner as in Example 1 except that an alternating voltage was applied so that the potential of the recorder was ± 90 V, and the surface sample 4 was formed. The surface property was evaluated in the same manner as above.
Table 1 shows the evaluation results of the type of resin powder, the potential for applying the recorder, the positive charge distribution ratio in the resin powder, and the surface property in Example 4.

(Example 5)
In Example 1, a surface sample was formed in the same manner as in Example 1 except that an alternating voltage was applied so that the potential of the recorder was ± 30 V, and the surface sample 5 was formed. The surface property was evaluated in the same manner as above.
Table 1 shows the evaluation results of the type of resin powder, the potential applied to the recoater, the positive charge distribution ratio in the resin powder, and the surface property in Example 5.

(Example 6)
Surface property is the same as in Example 1 except that polypropylene (PP) resin (trade name: Asphia-PP, manufactured by Aspect Co., Ltd.) is used instead of polybutylene terephthalate (PBT) resin in Example 1. The sample was shaped, the surface sample 6 was shaped, and the surface property was evaluated in the same manner as in Example 1.
Table 1 shows the evaluation results of the type of resin powder, the potential applied to the recoater, the positive charge distribution ratio in the resin powder, and the surface property in Example 6. The positive charge distribution ratio in the resin powder 2 produced using the polypropylene resin was 12%. Further, when the average charging potential of the resin powder 2 was calculated, it was a negative value.

(Example 7)
In Example 6, a surface sample was formed, a surface sample 7 was formed, and the same as in Example 1 except that a voltage was applied so that the potential of the recorder was 50 V. The surface quality was evaluated.
Table 1 shows the evaluation results of the type of resin powder, the potential applied to the recorder, the positive charge distribution ratio in the resin powder, and the surface property in Example 7.

(Example 8)
In Example 6, a surface sample was formed, a surface sample 8 was formed, and the surface sample 8 was formed in the same manner as in Example 6 except that a voltage was applied so that the potential of the recorder was −90 V. The surface property was evaluated in the same manner.
Table 1 shows the evaluation results of the type of resin powder, the potential applied to the recorder, the positive charge distribution ratio in the resin powder, and the surface property in Example 8.

(Example 9)
In Example 6, the surface sample was formed in the same manner as in Example 6 except that the alternating voltage was applied so that the potential of the recorder was ± 90 V, and the surface sample 9 was formed. The surface property was evaluated in the same manner as above.
Table 1 shows the evaluation results of the type of resin powder, the potential for applying the recoater, the positive charge distribution ratio in the resin powder, and the surface property in Example 9.

(Example 10)
In Example 6, a surface sample was formed in the same manner as in Example 6 except that an alternating voltage was applied so that the potential of the recorder was ± 30 V, and the surface sample 10 was formed. The surface property was evaluated in the same manner as above.
Table 1 shows the evaluation results of the type of resin powder, the potential applied to the recorder, the positive charge distribution ratio in the resin powder, and the surface property in Example 10.

(Example 11)
In Example 6, a surface sample was formed in the same manner as in Example 6 except that an alternating voltage was applied so that the potential of the recorder was ± 120 V, and the surface sample 11 was formed. The surface property was evaluated in the same manner as above.
Table 1 shows the evaluation results of the type of resin powder, the potential for applying the recoater, the positive charge distribution ratio in the resin powder, and the surface property in Example 11.

(Comparative Example 1)
In Example 1, a surface sample was formed, a surface sample 12 was formed, and the same as in Example 1 except that no voltage was applied to the recorder (potential was set to 0 V). The surface quality was evaluated.
Table 1 shows the evaluation results of the type of resin powder, the potential for applying the recoater, the positive charge distribution ratio in the resin powder, and the surface property in Comparative Example 1.

(Comparative Example 2)
In Example 6, a surface sample was formed, a surface sample 13 was formed, and the same as in Example 1 except that no voltage was applied to the recorder (potential was set to 0 V). The surface quality was evaluated.
Table 1 shows the evaluation results of the type of resin powder, the potential applied to the recoater, the positive charge distribution ratio in the resin powder, and the surface property in Comparative Example 2.

From the results in Table 1, by charging the layer forming means (recoater) as at least a part of the exposed surface facing the modeling layer, the surface property of the three-dimensional model is improved, and the modeling accuracy is deteriorated. It was found that molding defects can be suppressed.

Examples of aspects of the present invention are as follows.
<1> A three-dimensional model manufacturing device that manufactures a three-dimensional model using resin powder.
A layer forming means for forming a layer containing the resin powder and
A curing means for curing the layer containing the resin powder, and
A charging means for charging at least a part of the exposed surface facing the layer containing the resin powder in the three-dimensional model manufacturing apparatus.
It is a three-dimensional model manufacturing apparatus characterized by having.
<2> The apparatus for manufacturing a three-dimensional model according to <1>, wherein the exposed surface charged by the charging means is an exposed surface in the layer forming means facing the layer containing the resin powder.
<3> The apparatus for manufacturing a three-dimensional model according to any one of <1> to <2>, wherein the charging means charges at least a part of the exposed surface by applying a voltage.
<4> The apparatus for manufacturing a three-dimensional model according to any one of <1> to <3>, wherein at least a part of the exposed surface is made of metal.
<5> The apparatus for manufacturing a three-dimensional model according to any one of <1> to <4>, wherein the potential on at least a part of the exposed surface has the same sign as the average charging potential of the resin powder.
<6> The production of the three-dimensional model according to any one of <3> to <5>, wherein the charging means applies a voltage so that the potential on at least a part of the exposed surface changes at a predetermined cycle. It is a device.
<7> The apparatus for manufacturing a three-dimensional model according to any one of <3> to <6>, wherein the charging means applies a voltage so that the sign of the potential on at least a part of the exposed surface changes. is there.
<8> The apparatus for manufacturing a three-dimensional model according to any one of <1> to <7>, wherein the potential on at least a part of the exposed surface is -100 V or more and 100 V or less.
<9> A method for manufacturing a three-dimensional model using resin powder.
A layer forming step of forming a layer containing the resin powder and
A curing step of curing the layer containing the resin powder, and
A charging step of charging at least a part of the exposed surface of the member located opposite to the layer containing the resin powder, which is used when manufacturing the three-dimensional model.
It is a method for manufacturing a three-dimensional model, which is characterized by including.

According to the three-dimensional model manufacturing apparatus according to any one of <1> to <8> and the three-dimensional model manufacturing method according to <9>, the conventional problems are solved and the object of the present invention is achieved. Can be achieved.

JP-A-2015-157424

1 Electromagnetic irradiation source (example of curing means)
2 Reflector 3 Heater 4 Roller (Example of layer forming means)
4a Roller peripheral members 5 Supply tank 6 Laser scanning space 7 Chamber 7a Top plate in chamber 8 Swing gate 9a Voltage applying means (example of charging means)
9b Voltage applying means (example of charging means)
10 Modeling liquid 12 Flattening roller (part of layer forming means)
20 Resin powder 31 Modeling layer (an example of a layer containing resin powder)
52 Discharge head (example of curing means)
80 Light irradiation unit (example of curing means)
100a Three-dimensional model manufacturing device 100b Three-dimensional model manufacturing device 100c Three-dimensional model manufacturing device 100d Three-dimensional model manufacturing device

Claims (9)

It is a manufacturing device for three-dimensional shaped objects that manufactures three-dimensional shaped objects using resin powder.
A layer forming means for forming a layer containing the resin powder and
A curing means for curing the layer containing the resin powder, and
A charging means for charging at least a part of the exposed surface facing the layer containing the resin powder in the three-dimensional model manufacturing apparatus.
A device for manufacturing a three-dimensional object, which is characterized by having. The apparatus for manufacturing a three-dimensional model according to claim 1, wherein the exposed surface charged by the charging means is an exposed surface in the layer forming means facing the layer containing the resin powder. The apparatus for manufacturing a three-dimensional model according to any one of claims 1 to 2, wherein the charging means charges at least a part of the exposed surface by applying a voltage. The apparatus for manufacturing a three-dimensional model according to any one of claims 1 to 3, wherein at least a part of the exposed surface is made of metal. The apparatus for manufacturing a three-dimensional model according to any one of claims 1 to 4, wherein the potential on at least a part of the exposed surface has the same sign as the average charging potential of the resin powder. The apparatus for manufacturing a three-dimensional model according to any one of claims 3 to 5, wherein the charging means applies a voltage so that the potential on at least a part of the exposed surface changes at a predetermined cycle. The apparatus for manufacturing a three-dimensional object according to any one of claims 3 to 6, wherein the charging means applies a voltage so that the sign of the potential on at least a part of the exposed surface changes. The apparatus for manufacturing a three-dimensional model according to any one of claims 1 to 7, wherein the potential on at least a part of the exposed surface is -100 V or more and 100 V or less. It is a manufacturing method of a three-dimensional model that manufactures a three-dimensional model using resin powder.
A layer forming step of forming a layer containing the resin powder and
A curing step of curing the layer containing the resin powder, and
A charging step of charging at least a part of the exposed surface of the member located opposite to the layer containing the resin powder, which is used when manufacturing the three-dimensional model.
A method for manufacturing a three-dimensional model, which comprises.