JP2013241295A - Mixed powder for solid shaping and solid-shaped article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide inexpensive mixed powder for solid shaping capable of imparting sufficient strength to a solid-shaped article just after being formed, and the solid-shaped article.SOLUTION: Since mixed powder 26 for solid shaping containing hemihydrate gypsum and a gypsum hardening accelerator contains the gypsum hardening accelerator in the proportion in the range of ≥5.01 and ≤45 wt% with respect to the whole mixed powder 26 for solid shaping, inexpensive mixed powder 26 for solid shaping having quick hardening speed at the forming time and sufficient strength of a solid-shaped article just after being formed can be obtained. Namely, the inexpensive mixed powder 26 for solid shaping capable of imparting sufficient strength to a solid-shaped article 32 just after being formed can be provided.

Description

  The present invention relates to a mixed powder for three-dimensional modeling and a three-dimensional molded article produced by the mixed powder for three-dimensional modeling, and in particular, can provide sufficient strength to a three-dimensional molded article immediately after molding and is inexpensive. The present invention relates to an improvement for providing a body and a three-dimensional object.

  A three-dimensional object molding apparatus for forming a three-dimensional object by laminating a product produced from a mixed powder for three-dimensional modeling containing hemihydrate gypsum and a gypsum hardening accelerator and a modeling liquid containing water as a solvent. It has been known. For example, this is the 3D printing system described in Patent Document 1. In this technique, it is said that a three-dimensional structure excellent in strength can be formed by including a thermoplastic particle filling material in the mixed powder for three-dimensional modeling.

Special table 2007-502713

  However, in the conventional technology as described above, depending on the preparation of the mixed powder for three-dimensional modeling, a three-dimensional model is formed through a complicated reaction, so that the reaction rate is insufficient and sufficient strength is obtained immediately after molding. There was no case. In addition, the conventional mixed powder for three-dimensional modeling has an adverse effect that it is expensive depending on the type of substance contained. For this reason, development of the mixed powder for solid modeling and solid modeling which can give sufficient intensity to a solid modeling thing immediately after fabrication and was inexpensive was calculated | required.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to provide a sufficient amount of strength to a three-dimensional structure immediately after molding and to provide an inexpensive mixed powder for three-dimensional modeling and a three-dimensional structure. Is to provide.

  In order to achieve such an object, the gist of the first invention is a mixed powder for three-dimensional modeling including hemihydrate gypsum and a gypsum curing accelerator, wherein the proportion of the gypsum curing accelerator is as described above. It is in the range of 5.01 wt% or more and 45 wt% or less with respect to the whole mixed powder for three-dimensional modeling.

  Thus, according to the first aspect of the present invention, it is a mixed powder for three-dimensional modeling including hemihydrate gypsum and a gypsum curing accelerator, and the proportion of the gypsum curing accelerator is in the whole mixed powder for three-dimensional modeling. On the other hand, since it is in the range of 5.01% by weight or more and 45% by weight or less, the curing speed at the time of molding is high, the strength of the molded article immediately after molding is sufficient, and an inexpensive mixed powder for three-dimensional modeling is obtained. be able to. That is, it is possible to provide an inexpensive mixed powder for three-dimensional modeling that can give sufficient strength to the three-dimensional molded item immediately after molding.

  Here, in the first invention, preferably, the gypsum curing accelerator is dihydrate gypsum, alkali metal sulfate, alkaline earth metal sulfate, alkali metal chloride salt, alkaline earth metal chloride salt, It contains at least one of ammonium salts of inorganic acids and alums. If it does in this way, sufficient intensity | strength can be provided to the three-dimensional molded item immediately after shaping | molding using a practical and cheap gypsum hardening accelerator, and the cheap mixed powder for three-dimensional modeling can be provided.

  Preferably, the water-soluble resin is contained at a ratio of 10% by weight or less with respect to the whole mixed powder for three-dimensional modeling. If it does in this way, required and sufficient humidity can be provided to the said mixed powder for solid modeling.

  Preferably, the three-dimensional modeling mixed powder is sequentially laminated with a layered solidified product obtained by solidifying at least a part of the three-dimensional modeling mixed powder filled in layers with a modeling liquid using water as a solvent. This is used in a three-dimensional object molding apparatus for forming a three-dimensional object. In this way, it is possible to provide an inexpensive mixed powder for three-dimensional modeling that can give sufficient strength to a three-dimensional molded article immediately after molding, which is used in a three-dimensional molded article forming apparatus including a so-called 3D printer. .

  In order to achieve the above object, the gist of the second invention is that the product produced from the mixed powder for three-dimensional modeling of the first invention and a modeling liquid using water as a solvent is layered. It is a three-dimensional modeled object formed by being laminated on. If it does in this way, the intensity | strength immediately after shaping | molding is sufficient, and an inexpensive three-dimensional molded item can be provided.

It is a figure which shows roughly the structure of the three-dimensional molded item shaping | molding apparatus with which the mixed powder for three-dimensional modeling of this invention is used suitably. It is a figure which shows roughly about shaping | molding of the three-dimensional molded item by the three-dimensional molded item shaping | molding apparatus of FIG. It is a figure explaining the preparation method of the sample used in the test which this inventor performed in order to verify the effect of this invention. It is a figure explaining the preparation method of the sample used in the test which this inventor performed in order to verify the effect of this invention. It is a graph which shows the test result in the test which this inventor performed in order to verify the effect of this invention. It is a figure which expands and shows the range where the ratio of the gypsum hardening accelerator in the graph of FIG. 5 is 0 weight%-45 weight%. It is a graph which shows the other test result in the test which this inventor performed in order to verify the effect of this invention. It is a figure explaining the hardening time of the mixed powder containing water-soluble resin different from the sample shown in FIGS.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used for the following description, the dimensional ratios and the like of each part are not necessarily drawn accurately.

  FIG. 1 is a diagram schematically showing a configuration of a three-dimensionally shaped article forming apparatus 10 in which the three-dimensionally shaped mixed powder of the present invention is suitably used. In FIG. 1, the direction corresponding to the vertical direction is indicated by the z-axis, and the two directions orthogonal to each other on the horizontal plane are indicated by the x-axis and the y-axis, respectively. That is, the x-axis, y-axis, and z-axis shown in FIG. 1 indicate three directions that are orthogonal to each other. As shown in FIG. 1, the three-dimensional structure forming device 10 includes a frame portion 14 that is a frame-shaped member provided in a fixed position with respect to the frame 12, and the frame 12 ( A base 16 provided so as to be movable in the z-axis direction with respect to the frame portion 14), and a head 18 provided so as to be movable in the x-axis direction and the y-axis direction (in the xy plane) with respect to the base 16. Configured. Further, a base drive mechanism 22 that raises and lowers the base 16 in the z-axis direction with respect to the frame 12 (frame portion 14) by a driving force output from a motor (servo motor) 20, and the head 18 includes the base 18. And a head driving mechanism 24 that drives the base 16 in the x-axis direction and the y-axis direction (within the xy plane).

  FIG. 2 is a diagram schematically illustrating the formation of the three-dimensional structure by the three-dimensional structure forming apparatus 10. As shown in FIG. 2, the three-dimensional model forming apparatus 10 is a three-dimensional model that is an embodiment of the present invention filled in layers based on three-dimensional data corresponding to a three-dimensional model to be molded. , 30j (hereinafter simply referred to as the layered solid 30 unless otherwise distinguished), in which a part of the mixed powder 26 is solidified by a modeling liquid 28 using water as a solvent. ) Are sequentially laminated to form the three-dimensional structure 32. In FIG. 2, each layer of the layered solidified product 30 is indicated by a broken line. That is, the three-dimensional object molding apparatus 10 is called a three-dimensional molding machine (rapid prototyping) or a three-dimensional printer (3D printer) that forms a solid (three-dimensional object) based on three-dimensional data, for example. is there.

  That is, in the formation of the three-dimensional object by the three-dimensional object molding apparatus 10, first, the mixed powder for three-dimensional object is formed on the inner side of the frame portion 14 and vertically above the base 16 (upper side in the z-axis direction). The body 26 is filled in a layer shape having a thickness of, for example, about 0.1 to 0.3 mm corresponding to each layer of the layered solidified material 30, and the surface of the filled three-dimensional modeling mixed powder 26 (apparent surface) ) And the vertical upper surface of the frame portion 14 are scraped off by the wrinkles (not shown) or the like so as to be substantially flush with each other. Next, the modeling liquid 28 is injected from the head 18 to a position corresponding to a portion to be solidified in the three-dimensional modeling mixed powder 26 filled in the layered form, that is, a part of the three-dimensional modeled object 32 to be molded. (Dropped), and the portion is formed (solidified) as the layered solidified product 30. In FIG. 2, the solidified portion of the three-dimensional modeling mixed powder 26 is indicated by oblique lines. At this time, a part of the three-dimensional structure 32 to be molded is ejected while the head 18 is moved in the xy plane with respect to the base 16 by the head driving mechanism 24. The layered solidified product 30 corresponding to is formed. Next, the base 16 is lowered vertically by the base drive mechanism 22 with respect to the frame portion 14 (down in the z-axis direction) by a thickness corresponding to each layer of the layered solid material 30. . Thereafter, by repeating the same process, the layered solidified product 30 is sequentially laminated to form a three-dimensional modeled object, and the three-dimensional modeled mixed powder 26 that has not been solidified is removed. A shaped object 32 is obtained.

The mixed powder 26 for three-dimensional modeling of the present embodiment contains hemihydrate gypsum (CaSO ₄ .1 / 2H ₂ O: calcined gypsum) and a gypsum hardening accelerator. This gypsum accelerator is preferably dihydrate gypsum (CaSO ₄ .2H ₂ O), alkali metal sulfate, alkaline earth metal sulfate, alkali metal chloride salt, alkaline earth metal chloride salt, inorganic It contains at least one of acid ammonium salts and alums. The proportion of the gypsum curing accelerator is within the range of 5.01 wt% or more and 45 wt% or less, preferably 5.01 wt% or more and 20 wt% or less with respect to the whole mixed powder for three-dimensional modeling 26. Within range. In other words, the proportion of the gypsum curing accelerator is in the range of more than 5% by weight to 45% by weight or less, preferably more than 5% by weight and preferably 20% by weight with respect to the whole mixed powder for three-dimensional modeling 26 Within the following range. Whether the proportion of the gypsum hardening accelerator is less than 5.01% by weight or more than 45% by weight with respect to the entire mixed powder for three-dimensional modeling 26, the mixed powder for three-dimensional modeling There is a possibility that curing after the molding of S26 will be delayed, and sufficient strength cannot be imparted to the three-dimensional structure 32. The particle sizes of the hemihydrate gypsum and the gypsum curing accelerator can be appropriately set according to the specifications of the mixed powder for three-dimensional modeling, but are preferably about 5 to 150 μm, for example.

  The three-dimensional modeling mixed powder 26 preferably contains a water-soluble resin at a ratio of 10 wt% or less with respect to the entire three-dimensional modeling mixed powder 26. Examples of the water-soluble resin include gum arabic, Metrose (nonionic water-soluble cellulose ether obtained by treating cellulose with caustic soda and then reacting with an etherifying agent such as methyl chloride), and Kelzan (xanthan gum as a component). Natural polymer polysaccharides), partially neutralized sodium polyacrylate, or water-soluble polymers such as polyvinyl alcohol (PVA) are preferably used. When the proportion of the water-soluble resin is larger than 10% by weight with respect to the entire three-dimensional mixed powder 26, the three-dimensional mixed powder 26 is excessively wetted, resulting in poor shape retention. There is a possibility that the curing speed after molding may be delayed.

  As described above, the mixed powder for three-dimensional modeling preferably includes 5.01% by weight to 45% by weight of the gypsum accelerator and 0% by weight to 10% by weight of the water-soluble resin. It is a mixed powder containing a proportion, the remaining proportion being hemihydrate gypsum. That is, the ratio of the hemihydrate gypsum is in the range of 45 wt% or more and 94.99 wt% or less with respect to the entire three-dimensional mixed powder 26.

  Subsequently, a test conducted by the present inventor in order to verify the effect of the present invention will be described. The present inventor prepared a mixed powder by changing the proportions of hemihydrate gypsum, gypsum curing accelerator, and water-soluble resin in various ranges within the following ranges. Measured by method.

[Mixed powder ratio]
・ Hemihydrate gypsum: 13 to 93% by weight
・ Hardening accelerator (dihydrate gypsum): 0 to 80% by weight
(Potassium sulfate): 0 to 45% by weight
・ Water-soluble resin (gum arabic): 0 to 10% by weight

[Curing time measurement method]
(A) 4 to 5 g of mixed powder (mixed water ratio: 15% by weight) mixed with 0.6 to 0.75 g of water is mixed and mixed for 30 seconds with a rubber device (slag).
(B) Mixing mixed in (a) in a cylindrical rubber mold 34 having an inner diameter φ = 20 mm × height h = 30 mm as shown in FIG. 3 and having a rubber lid 36 fitted in the bottom. The body is pushed in, and after one minute has passed, the rubber lid 36 is pushed out as shown in FIG. 4 to obtain a cylindrical test piece (modeled article) 38.
(C) Time when the surface shape change of the test piece 38 obtained in (b) cannot be visually observed with a well-known Vicat needle (φ2 mm × 300 g) is measured as the curing time.

  FIG. 5 is a graph showing the curing time in each sample in which dihydrate gypsum was used as the gypsum curing accelerator and gum arabic was used as the water-soluble resin, and the ratios of the dihydrate gypsum and gum arabic were variously changed. FIG. 6 is an enlarged view showing the range of the gypsum hardening accelerator in FIG. 5 in the range of 0 wt% to 45 wt%. In FIGS. 5 and 6, the curing time of the sample containing no gum arabic as a water-soluble resin (0% by weight) is 7% by weight, and the curing time of the sample containing 2% by weight is 7% by weight. The curing time of the sample including the ratio is indicated by a two-dot chain line, and the curing time of the sample including the ratio of 10% by weight is indicated by a broken line.

  As shown in FIGS. 5 and 6, the sample containing no water-soluble resin (0% by weight) has a ratio of dihydrate gypsum as a gypsum hardening accelerator within the range of 5.01% to 45% by weight. The curing time was within 2 minutes. In addition, a sample containing 2% by weight of gum arabic as a water-soluble resin has a curing time of 3.1 to 60% by weight of dihydrate gypsum as a gypsum curing accelerator. Within 5 minutes. A sample containing 7% by weight of gum arabic as a water-soluble resin has a curing time of 4.5 minutes within a range of 3% to 45% by weight of dihydrate gypsum as a gypsum curing accelerator. The curing time was within 3.5 minutes within the range of 5.01 wt% to 20 wt%. Further, a sample containing 10% by weight of gum arabic as a water-soluble resin has a curing time of 6 minutes within a range of 5.01% to 45% by weight of dihydrate gypsum as a gypsum curing accelerator. Was within. On the other hand, in a sample having a dihydrate gypsum ratio of 5% by weight or less (less than 5.01% by weight) or greater than 45% by weight as a gypsum hardening accelerator, the ratio of dihydrate gypsum is not dependent on the content of the water-soluble resin. It can be seen that the curing time is longer than that of the sample in the range of 5.01 wt% to 45 wt%. This tendency is particularly remarkable in a sample having a dihydrate gypsum ratio of less than 5.01% by weight, and it can be seen that as the dihydrate gypsum ratio approaches 0, the curing time increases rapidly.

  FIG. 7 is a graph showing the curing time in each sample using potassium sulfate as the gypsum accelerator and gum arabic as the water-soluble resin, and varying the ratios of potassium sulfate and gum arabic. In FIG. 7, the curing time of a sample containing no gum arabic as a water-soluble resin (0% by weight) is 2% by weight, and the curing time of a sample containing 2% by weight is included by a dashed line at a rate of 10% by weight. The curing time of the sample is indicated by broken lines. As shown in FIG. 7, the sample containing no water-soluble resin (0% by weight) has a curing time of 2 within a range where the ratio of potassium sulfate as a gypsum curing accelerator is 5.01% to 45% by weight. Within minutes. A sample containing 2% by weight of gum arabic as a water-soluble resin has a curing time of 3.5% within a range of 5.01% to 45% by weight of potassium sulfate as a gypsum curing accelerator. Within minutes. A sample containing 10% by weight of gum arabic as a water-soluble resin has a ratio of potassium sulfate as a gypsum curing accelerator within a range of 5.01% to 45% by weight and a curing time within 4 minutes. Met. On the other hand, in a sample having a potassium sulfate ratio of 5% by weight or less (less than 5.01% by weight) as a gypsum accelerator, the potassium sulfate ratio is 5.01% to 45% regardless of the content of the water-soluble resin. It can be seen that the curing time is longer than that of the sample in the range of% by weight.

  FIG. 8 is a diagram for explaining the curing time of a mixed powder containing a water-soluble resin different from the samples shown in FIGS. In the example shown in FIG. 8, the curing time in the mixed powder prepared by mixing 85 wt% of hemihydrate gypsum, 10 wt% of dihydrate gypsum as a gypsum hardening accelerator, and 5 wt% of a water-soluble resin, The comparison is made for each type of water-soluble resin. As shown in FIG. 8, the sample containing polyvinyl alcohol (PVA) as the water-soluble resin has a curing time of 2.75 minutes, and the sample containing Metroses has a curing time of 2.75 minutes. The sample containing it has a setting time of 2.5 minutes, the sample containing Kelzan has a setting time of 2.75 minutes, and the same setting time as the sample containing gum arabic as a water-soluble resin (setting time 2.5 minutes). I understand that That is, the test results shown in FIGS. 5 to 7 are the same for the three-dimensional modeling mixed powder containing polyvinyl alcohol (PVA), Metrose, sodium polyacrylate partial neutralized product, or Kelzan as a water-soluble resin. The result is considered to be obtained.

  In the molding of a three-dimensional model using the three-dimensional modeled mixed powder in the three-dimensional model molding apparatus 10 or the like, the three-dimensional model in which the curing time when the modeling liquid is applied to the three-dimensional modeled mixed powder is molded. Corresponding closely with the strength of the object, the shorter the curing time, the more excellent the three-dimensional modeled object. For example, in a test conducted by the present inventor separately from the above-described test, a solid powder for solid modeling within a curing time of 6 minutes is put into a three-dimensional model creating apparatus 10 as shown in FIG. When the shaped article 32 was created, the three-dimensional shaped article 32 having sufficient strength was formed. On the other hand, when using a 3D modeling mixed powder with a curing time exceeding 6 minutes, such as a curing time of 7 minutes or more, it is confirmed that curing after molding is insufficient and sufficient handling enhancement cannot be obtained. It was done. That is, in the three-dimensional modeling mixed powder used in the three-dimensional model molding apparatus 10 or the like, it is desirable that the curing time is within 6 minutes. From the test results shown in FIGS. The accelerator contains 5.01 wt% or more and 45 wt% or less, preferably 5.01 wt% or more and 20 wt% or less, the water-soluble resin is contained in a proportion of 0 wt% or more and 10 wt% or less, and the remaining proportion is It has been proved that sufficient strength can be imparted to the three-dimensional molded article 32 after molding if it is a mixed powder for three-dimensional modeling that is made of hemihydrate gypsum.

  Thus, according to the present embodiment, the proportion of the gypsum accelerator is within the range of 5.01% by weight or more and 45% by weight or less with respect to the entire mixed powder for three-dimensional modeling 26, It is possible to obtain a mixed powder 26 for three-dimensional modeling that has a fast curing speed at the time of molding, has a sufficient strength of a molded article immediately after molding, and is inexpensive. That is, it is possible to provide an inexpensive mixed powder 26 for three-dimensional modeling that can give sufficient strength to the three-dimensional molded article 32 immediately after molding.

  Further, the gypsum accelerator includes dihydrate gypsum, alkali metal sulfate, alkaline earth metal sulfate, alkali metal chloride salt, alkaline earth metal chloride salt, ammonium salt of inorganic acid, and alum. Since it contains at least one kind, it is possible to provide a low-priced mixed powder 26 for three-dimensional modeling that can give sufficient strength to the three-dimensional structure 32 immediately after molding using a practical and inexpensive gypsum curing accelerator. it can.

  In addition, since the water-soluble resin is contained at a ratio of 10% by weight or less with respect to the entire mixed powder for three-dimensional modeling 26, necessary and sufficient humidity can be given to the mixed powder for three-dimensional modeling 26.

  In addition, the three-dimensional modeling mixed powder 26 is formed by sequentially laminating at least a part of the three-dimensional modeling mixed powder 26 filled in layers with a modeling liquid containing water as a solvent. Since it is used in the three-dimensional object molding apparatus 10 that forms the three-dimensional object 32 by the above, the strength sufficient for the three-dimensional object 32 immediately after molding, which is used in the three-dimensional object molding apparatus 10 including a so-called 3D printer. Can be provided and an inexpensive mixed powder 26 for three-dimensional modeling can be provided.

  Further, according to the present embodiment, the three-dimensional structure 32 formed by laminating a product generated from the mixed powder for three-dimensional modeling 26 and a modeling liquid 28 using water as a solvent is laminated. Therefore, it is possible to provide a three-dimensional model 32 that has sufficient strength immediately after molding and is inexpensive.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other modes.

  For example, in the above-described embodiments, gypsum hardening accelerators include dihydrate gypsum, alkali metal sulfate, alkaline earth metal sulfate, alkali metal chloride salt, alkaline earth metal chloride salt, ammonium salt of inorganic acid The three-dimensional modeling mixed powder 26 including at least one of alums has been described. However, the present invention is not limited to this, and various types may be used depending on the specifications of the three-dimensional modeling mixed powder. A gypsum accelerator may be appropriately selected and used.

  Although not specifically mentioned in the above-described embodiments, the mixed powder for three-dimensional modeling of the present invention includes an adhesive particle material and a filler in addition to the gypsum curing accelerator and the water-soluble resin, depending on the specifications. Needless to say, various materials can be appropriately contained.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

  10: 3D modeling apparatus, 26: Mixed powder for 3D modeling, 28: Modeling liquid, 30: Layered solidified product, 32: 3D modeling product

Claims (5)

A mixed powder for three-dimensional modeling containing hemihydrate gypsum and a gypsum curing accelerator,
The ratio of the said gypsum hardening accelerator is in the range of 5.01 weight% or more and 45 weight% or less with respect to the said mixed powder for three-dimensional modeling, The mixed powder for three-dimensional modeling characterized by the above-mentioned.   The gypsum accelerator is at least one of dihydrate gypsum, alkali metal sulfate, alkaline earth metal sulfate, alkali metal chloride salt, alkaline earth metal chloride salt, ammonium salt of inorganic acid, and alum. The mixed powder for three-dimensional modeling according to claim 1, wherein the mixed powder is a type.   The mixed powder for three-dimensional modeling according to claim 1 or 2, wherein the mixed powder for three-dimensional modeling contains a water-soluble resin at a ratio of 10 wt% or less with respect to the entire mixed powder for three-dimensional modeling.   The three-dimensional modeling mixed powder is obtained by sequentially laminating a layered solidified product obtained by solidifying at least a part of the three-dimensional modeling mixed powder filled in layers with a modeling liquid using water as a solvent. The mixed powder for three-dimensional modeling according to any one of claims 1 to 3, which is used in a three-dimensional model molding apparatus for molding.   The three-dimensional modeled object formed by laminating a product generated from the mixed powder for three-dimensional model modeling according to any one of claims 1 to 4 and a modeling liquid containing water as a solvent. .

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