ES2878276T3 - Particle for solid freeform fabrication - Google Patents

Abstract

A polymer particle (21) having a columnar shape having end surfaces (22a, 23a) and a side surface (24), wherein the particle comprises at least one perimeter area (22b; 23b) that is substantially orthogonal and continuous with one of the end surfaces (22a, 23a) through a curved surface to partially cover the side surface (24).

Description

DESCRIPTION

Particle for solid freeform fabrication

Background

Technical field

The present disclosure relates to a particle according to claim 1, a method of manufacturing a solid free-form manufacturing object according to claim 13 and a manufacturing method of a powder for the solid free-form manufacturing of according to claim 14.

Description of Related Art

A powder bed fusion (PBF) method is known as a method of fabricating a solid free-form fabrication object (three-dimensional object). The PBF method includes a selective laser sintering (SLS) method to form a solid free-form fabrication object by selective irradiation of laser beams and a selective mask sintering (SMS) method in the that laser beams are applied flat using a mask. Furthermore, known methods of manufacturing solid free-form fabrication objects other than the PBF method include a high speed sintering (HSS) method using ink, a binder jetting (BJ) method, etc. .

As a resin powder for use in making a solid free-form fabrication object, for example, a molten resin liquid is extruded and subsequently expanded (stretched) to form a resin fiber, which is fixed with a movable clamp and moves towards a cutting blade, where the resin fiber is cut to obtain a resin powder having a substantially cylindrical resin powder (WO 2017/112723 A1).

However, the resin powder disclosed in the above-mentioned WO 2017/112723 A1 is deficient in packing density, so that a solid free-form fabrication object formed by using the resin powder is deficient in as for resistance.

Summary

The solid free-form fabrication particle of the present disclosure has excellent packing density, so that a solid free-form fabrication object formed by using the resin powder is excellent in strength.

In accordance with the present invention, an improved particle (21) is provided for solid freeform fabrication including a columnar shape having end surfaces (22; 23) and a side surface (24), wherein one of the End surfaces (22; 23) partially cover side surface (24).

Brief description of the various views of the drawings

Various other objects, features, and consequent advantages of the present invention will be more fully appreciated as the same is better understood from the detailed description, considered in connection with the accompanying drawings, in which like reference numerals designate similar corresponding parts in all of them and where:

FIG. 1 is a photograph illustrating an example of the solid free-form manufacturing powder;

FIG. 2 is a photograph illustrating an example of a particle for solid free-form manufacturing;

FIG. 3A is a diagram illustrating a schematic perspective view of an example of a solid free-form manufacturing particle having a cylindrical shape;

FIG. 3B is a diagram illustrating a side view of an example of the solid freeform manufacturing particle having a cylindrical shape illustrated in FIG. 3A;

FIG. 3C is a diagram illustrating a side view of an example of the solid free-form manufacturing particle having a cylindrical shape without a point at the ends;

FIG. 3D is a diagram illustrating a side view of an example of the solid free-form manufacturing particle having a cylindrical shape without a point at the ends;

FIG. 3E is a diagram illustrating a side view of an example of the solid freeform manufacturing particle having a cylindrical shape without a point at the ends;

FIG. 3F is a diagram illustrating a side view of an example of the solid freeform manufacturing particle having a cylindrical shape without a point at the ends;

FIG. 3G is a diagram illustrating a side view of an example of the solid free-form manufacturing particle having a cylindrical shape without a point at the ends;

FIG. 3H is a diagram illustrating a side view of an example of the solid freeform manufacturing particle having a cylindrical shape without a point at the ends;

FIG. 3I is a diagram illustrating a side view of an example of the solid freeform manufacturing particle having a cylindrical shape without a point at the ends;

FIG. 4 is a schematic diagram illustrating an example of a cut product formed by cutting a resin having a cylindrical shape in a diagonal direction;

FIG. 5 is a schematic diagram illustrating a device for making a solid free-form fabricated object in accordance with one embodiment of the present disclosure;

FIGS. 6A and 6B are concept diagrams illustrating examples of the fabrication method of a solid free-form fabrication object; Y

FIGS. 7A and 7B are concept diagrams illustrating other examples of the method of fabrication of a solid free-form fabrication object.

The preferred embodiments of the present disclosure having been generally described, a further understanding may be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting. In the descriptions of the following examples, the numbers represent weight ratios in parts, unless otherwise specified.

Detailed description of the realizations

In describing the embodiments illustrated in the drawings, specific terminology is used for the sake of clarity. However, the disclosure of the present specification is not intended to be limited to the specific terminology so selected and each specific element is to be understood to include all technical equivalents that have a similar function, function in a similar manner and achieve a similar result.

As used herein, the singular forms "a", "an / an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise.

Moreover, imaging, registration, printing, modeling, etc. in the present disclosure they have the same meaning, unless otherwise specified.

Aspects of the present disclosure are described below. The solid free form manufacturing particle described below is only an example and the present disclosure is not limited thereto. Therefore, the particle can be used for a surface shrinkage agent, a spacer, a lubricant, a paint, a grinding stone, an additive, a secondary battery separator, food, cosmetics, clothing, automobiles, precision instruments. , semiconductors, aerospace, medicine, metal substitute material, etc.

Solid Freeform Fabrication Resin Powder

The solid free-form manufacturing powder according to the present embodiment means an aggregate of a plurality of granular materials and has a columnar shape having end surfaces and a side surface, and one of the end surfaces partially covers the surface. side. In addition, the solid freeform fabrication powder may include particles other than the solid freeform fabrication particles described below.

Solid Freeform Manufacturing Particle

Particle form for solid free form fabrication

First, referring to FIG. 1 and FIG. 2, solid free form manufacturing particles (hereinafter also referred to as column products) are described. FIG. 1 is a photograph illustrating an example of the solid free-form manufacturing powder. Also, the columnar product surrounded by the dotted circle in FIG. 1 is one of a plurality of columnar products present in FIG. 1. FIG. 2 is a photograph illustrating an example of the solid free-form manufacturing particle. FIG. 1 and FIG. 2 are photographs by scanning electron microscope (SEM) observation. Such a photograph (projected image) can be obtained not only by SEM, but also with a known image analyzer, such as an optical microscope. In the following description, the SEM is used as an example as a device to obtain a projected image.

As illustrated in FIG. 2, a column (column product) 21 includes a first surface 22 as an example of the end surface and a second surface 23 as an example of the end surface and a side surface 24. The first surface 22 includes a first opposite surface 22a and a first perimeter area 22b having a shape that extends along the lateral surface 24. The first perimeter area 22b is a continuous surface with the opposite first surface 22a across a curved surface and substantially orthogonal to the first surface. opposite 22a. The second surface 23 includes a second opposing surface 23a that faces toward the first opposing surface 22a and a second perimeter area 23b that has a shape that extends along the lateral surface 24. The second perimeter area 23b is a continuous surface with the second opposite surface 23a through a curved surface substantially orthogonal to the second opposite surface 23a. The side surface 24 is adjacent to first surface 22 and second surface 23. Furthermore, first perimeter area 22b and second perimeter area 23b extend over side surface 24. In other words, side face 24 is covered in such a way that the end face of the column 21 is bent. As in the present embodiment, it is preferable that both end surfaces cover the entire circumference of the side surfaces in the area observed by an s Em. However, it is permissible for both end surfaces to partially cover the side faces, one of the end surfaces to cover the entire circumference of the side surface or one of the end surfaces to partially cover the side face. Furthermore, it is preferable that both end surfaces cover the entire circumference of the side surfaces not only in the area observed by SEM, but also in the area not observed by SEM. However, it is permissible for both end surfaces to partially cover the side faces, one of the end surfaces to cover the entire circumference of the side surface or one of the end surfaces to partially cover the side face.

The shape of the first perimeter area 22b and the second perimeter area 23b (both also hereinafter referred to as the perimeter area) is at least distinguishable from the side surface 24 in an SEM image, etc. For example, a shape of the perimeter area partially integrated with the side surface 24, a shape of the perimeter area adjacent to the side surface 24 and a shape having a space between the perimeter area and the side surface 24 are allowed. Furthermore, the former Perimeter area 22b and second perimeter area 23b are preferably located along a surface direction substantially identical to the surface direction of side surface 24.

As illustrated in FIG. 2, the first perimeter area 22b and the second perimeter area 23b extend along the side surface 24 and lie thereon. Furthermore, each of the structures of the first surface 22 and the second surface 23 covering around the connecting area of the first perimeter area 22b and the second perimeter area 23b and the side surface 24 is also called a bottle cap shape.

The first perimeter area 22b and the second perimeter area 23b are, respectively, shapes of the first surface 22 and the second surface 23 that extend along the side surface 24. Therefore, the first perimeter area 22b and the first Opposing surface 22a and the second perimeter area 23b and the second opposing surface 23a continue smoothly through curved surfaces. Due to the first perimeter area 22b and the second perimeter area 23b, the column 21 is free from a corner portion (pointed) or the proportion of the corner portion is reduced. Therefore, the packing density of the solid free-form fabrication powder, including the column 21, can be increased, thereby enhancing the tensile strength of an obtained solid free-form fabrication object. In addition, due to the column 21 without a corner portion, the fluidity of the solid free-form manufacturing powder can be enhanced, including the column 21, so that the poor movement of the solid free-form manufacturing powder can be reduced during solid freeform fabrication, thereby enhancing the tensile strength of an obtained solid freeform fabrication object. Furthermore, column 21 where the entirety of the first perimeter area 22b and the entirety of the second perimeter area 23b extend along (i.e. cover) the side surface 24 can enhance packing density and fluidity of the column 21 required as powder for solid free form fabrication.

The first perimeter area 22b and the second perimeter area 23b, where the first surface 22 and the second surface 23 of the column 21 cover the side surface 24, preferably have a minimum length of 1 pm or more, more preferably 3 pm or more and even preferably 5 pm or more along the height direction of the column 21.

When the minimum length is 1 pm or more, the curved surface between the first opposite surface 22a and the first peripheral area 22b and the curved surface between the second opposite surface 23a and the second peripheral area 23b are smoother, increasing, from that thus, the packing density of the solid free-form fabrication powder including the column 21 and enhancing the tensile strength of an obtained solid free-form fabrication object. Also, the curved surface becomes smoother. As a result, the fluidity of the solid free-form manufacturing powder, including the column 21, can be enhanced, so that poor movement of the powder during solid free-form manufacturing can be reduced, thereby enhancing the strength. to the tensile strength of an obtained solid free-form fabrication object. The first peripheral area and the second peripheral area preferably have a maximum length of 10 µm or more and more preferably 15 µm or more along the height direction of column 21. This length is determined in the area observed in the area projected by SEM, etc.

The shape of the column 21 is not particularly limited and can be suitably selected to suit a particular application. Examples are substantially cylindrical shapes and substantially prismatic shapes. Substantially prismatic shapes are preferable. Substantially cylindrical shapes and substantially prismatic shapes include solid shapes having the first peripheral area 22b and the second peripheral area 23b. The shapes of the first opposing surface 22a and the second opposing surface 23a are determined depending on the shape of the column 21. For example, in a case where a line (corner) is not observed in the height direction of the column 21, While a smooth surface is uniformly observed, column 21 is substantially cylindrical and the first opposing surface and the second opposing surface are substantially circular. For example, in a case where multiple surfaces are observed segmented by a line (corner) at the height direction of column 21, column 21 is substantially prismatic and the first opposite surface and the second opposite surface are substantially polygonal. It should be noted that a combination of a substantially polygonal first opposing surface 22a and a substantially circular second opposing surface 22b and vice versa is allowed.

As described above, column 21 has the first opposing surface 22a and the second opposing surface 23a opposing each other. The first opposing surface 22a may be inclined against the second opposing surface 23a. However, the first opposing surface 22a and the second opposing surface 23a are preferably substantially parallel to each other. The fact that both are substantially parallel to each other improves the flowability of the powder for solid free form manufacturing, including column 21.

The ratio of the maximum length of the straight line drawn on the first opposite surface 22a or the second opposite surface 23a of column 21 to the height of column 21 is 0.5 to 5.0, more preferably 0.7 to 2.0 and even preferably from 0.8 to 1.5.

Substantially cylindrical shape

The substantially cylindrical shape is not particularly limited and can be suitably selected to suit a particular application. Examples are a substantially perfectly circular cylindrical shape having a substantially perfectly circular first opposing surface 22a and a substantially perfectly circular second opposing surface 23a and a substantially ellipsoidal cylindrical shape having a substantially perfectly ellipsoidal first opposing surface 22a and a second. opposite surface 23a substantially ellipsoidal. Of these, a perfectly cylindrical shape is preferable. The circular portion of the substantially cylindrical shape can be partially omitted. Also, the substantial circle has a major axis to minor axis ratio of 1 to 10.

The size of the area of the first opposing surface 22a and the size of the area of the second opposing surface 23a may not be completely identical, but the ratio of the diameter of the circle of the large surface to the small surface is preferably 1.5 or less. More preferably, the ratio is 1.1 or less in the sense that the same shape can be packed more densely.

The diameter of the substantially cylindrical shape has no particular limit and can be suitably selected to suit a particular application. For example, the diameter is preferably 5 to 100 µm. When the substantially circular portion of the substantially cylindrical shape is substantially an ellipse, the diameter means the major axis.

The height of the substantially cylindrical shape has no particular limit and can be suitably selected to suit a particular application. For example, the height is preferably 5 to 100 µm.

Substantially polygonal prism

The shape of the substantially polygonal prism is not particularly limited and can be suitably selected to suit a particular application. Examples are polygonal prisms having an opposing first polygonal surface 22a and an opposing second polygonal surface 23a having a shape of a substantially rectangular parallelepiped, a substantially cubic prism, a substantially triangular prism, a substantially hexagonal prism, etc. Of these, a substantially hexagonal prism is preferable and a substantially regular hexagonal prism is more preferable. In a substantially polygonal prism, the particles (powder) can be packed without a gap so that the tensile strength of an obtained solid free-form fabrication object can be enhanced. It should be noted that the substantially polygonal prism can be partially omitted.

The size of the area of the first opposing surface 22a and the size of the area of the second opposing surface 23a may not be completely identical, but the ratio of the average of the sides of a polygon of the large surface to the small surface is preferably 1.5 or less. More preferably, the ratio is 1.1 or less in the sense that the same shape can be packed more densely.

The length of the longest straight line drawn on the first opposing surface 22a and the second opposing surface 23a of a substantially polygonal prism has no particular limit and can be suitably selected to suit a particular application. For example, this is preferably 5 to 100 µm.

The height of the substantially polygonal prism has no particular limit and can be suitably selected to suit a particular application. For example, the height is preferably 5 to 100 µm.

In the present disclosure, the side that forms the height between the first opposing surface 22a and the second opposing surface 23a of the column 21 includes a collapsed state (for example, a barrel-like shape in the case of a cylindrical shape) as a result of the softening of the resin in the cut. However, a space appears between powders that have arches. Therefore, the side is preferably straight in the sense of denser powder packing.

Shape without tip (vertex)

Column 21 preferably has no tips (vertices). The tip means an angular portion present when the column 21 is viewed from the side. The shape of column 21 is described with reference to FIGS. 3A to 3I. FIG. 3A is a diagram illustrating a schematic perspective view of an example of a solid free-form manufacturing particle having a cylindrical shape. FIG. 3B is a diagram illustrating a side view of an example of the solid freeform manufacturing particle having a cylindrical shape illustrated in FIG.

3A. FIG. 3C is a diagram illustrating a side view of an example of the solid freeform manufacturing particle having a cylindrical shape without a point at the ends. FIGS. 3D to 3I are diagrams illustrating side views of examples of the solid freeform fabrication powder having a cylindrical shape with no end tips.

When the cylindrical shape illustrated in FIG. 3A viewed from the side, the shape is rectangular, as illustrated in FIG. 3B. This has angular portions, that is, four points. In FIGS. 3C to 3I, examples of shapes without end tips are illustrated. Whether a column product has a spike can be determined by a projected image of the lateral plane of the column product. For example, the side of a columnar particle is observed by a scanning electron microscope (S4200, manufactured by Hitachi Ltd), etc. to obtain a two-dimensional image. In this case, the projected image has four sides. When the portion formed by two adjacent sides is defined as an end part, if the end part is formed by only two adjacent straight lines, an angle is formed and the particle has a point. If the end portion is arched, as illustrated in FIGS. 3C to 3I, no point is formed in the end portion.

Particle Quantity for Solid Free Form Manufacturing (Column Product)

The proportion (based on the number) of the column product contained in the solid free form manufacturing powder is preferably 50 percent or more and more preferably 70 percent or more relative to the solid free form manufacturing powder.

As the proportion of the column product having the above-mentioned first peripheral area and second peripheral area in the solid free-form manufacturing powder, the packing density of the solid free-form manufacturing powder including the columnar product and the tensile strength of an obtained solid free-form fabrication object. In addition, as the proportion of the column product having the above-mentioned first peripheral area and second peripheral area in the solid free-form manufacturing powder, the flowability of the solid free-form manufacturing powder can be enhanced, including the columnar product, so that poor movement of solid freeform fabrication powder can be reduced during solid freeform fabrication, thereby enhancing the tensile strength of a solid freeform fabrication object obtained.

A specific method of calculating the quantity of the product in the column is the following: that is, a photograph of the powder is taken with a magnification of 150 times using an SEM, and the number of powder particles for manufacturing of solid free form and the number of products in column. Then, the number of the column products is divided by the number of solid free-form manufacturing powder and multiplied by 100 to get the amount (ratio).

The magnification power of the SEM is suitably changed in accordance with the size of the powder for solid free-form manufacturing. Also, when counting the number of solid free-form manufacturing powder particles and the number of column products in the SEM image, only the solid free-form manufacturing powder particle and the column product having a longer part of 20 pm or more in the SEM image in the present application. In addition, the number of solid free form manufacturing powder particles is 100 when the column product ratio is calculated.

The proportion (based on the number) of the column product having a substantially polygonal prism contained in the solid free form manufacturing powder is preferably 40 percent or more relative to the solid free form manufacturing powder.

As the proportion of the columnar product having a substantially polygonal prism having the aforementioned first peripheral area and the second peripheral area in the solid free-form manufacturing powder increases, the packing density of the manufacturing powder is enhanced. solid free form including columnar product and tensile strength of a solid free form fabricated object obtained as described above.

Particle crystallinity for solid free form fabrication (column product)

The column product is made of a thermoplastic resin. The thermoplastic resin plasticizes and melts after the application of heat. As thermoplastic resins, crystalline resins can be used. Crystalline resin has a melting peak measured in accordance with ISO 3146 (plastic transition temperature measurement method, JIS K7121 format).

A controlled glass crystalline thermoplastic resin is preferable as the crystalline resin. Of these, a crystalline thermoplastic resin having a crystal size and crystal alignment controlled by a method of external stimuli, such as heat, expansion, crystalline core material, and ultrasonic treatment is more preferable.

The manufacturing method of the crystalline thermoplastic resin has no particular limit and can be suitably selected to suit a particular application. For example, the resin is heated to glass transition temperature or higher and is subsequently annealed with an optional addition of crystal nucleating agent prior to annealing to enhance crystallinity. Also suitable are a method of applying an ultrasonic wave to enhance crystallinity, a method of dissolving a resin in a solvent and slow evaporation of the solvent to enhance crystallinity, a method of applying an external electric field to grow the glass or expansion and subsequently subjecting the highly oriented or highly crystallized product to a process, such as spraying, cutting, etc.

For annealing, the resin is heated to a temperature 50 degrees higher than its glass transition temperature for three days and subsequently slowly cooled to room temperature.

The molten liquid for solid free form manufacturing is extruded into fibrous form by an extruder during stirring at temperatures of 30 degrees C or more above the melting point. The molten liquid is spread (stretched) to between about 1/1 and about 1/10 to obtain fibers. The maximum extension ratio can be changed depending on the viscosity of the resin and the melt.

In the ultrasonic wave application, the solvent glycerin (reagent grade, manufactured by Tokyo Chemical Industry Co. Ltd.) is added to a resin in an amount five times that of the resin, followed by heating to the temperature of 20 degrees C higher than melting point. Subsequently, ultrasonic waves are applied to them by an ultrasound generator (UP200S ultrasonicator, manufactured by Hielscher Ultrasonics GmbH) at a frequency of 24 KHz and an amplitude of 60 percent for two hours. Subsequently, the resulting product is rinsed with an isopropanol solvent at room temperature, preferably followed by drying under vacuum.

In external electric field application, after heating a resin to glass transition temperature or higher, an alternating electric field (500 Hz) of 600 V / cm is applied to it for one hour, followed by slow cooling.

In the powder bed fusion (PBF) method, a large temperature difference (temperature window) is preferable over the change of glass layer to avoid deformations during the fabrication of a solid free-form fabrication object. It is preferable that the change of glass layer is larger since the resin powder having a large difference between the melting start temperature and the recrystallization point during cooling has better manufacturing properties.

Particle composition for solid free-form manufacturing (columnar product)

Specific examples of the resin constituting the column product include, but are not limited to, polymers, such as polyolefin, polyamide, polyester, polyether, polyphenylene sulfide, liquid crystal polymer (LCP), polyacetal (POM, point of 175 degree C melt), polyimide and a fluorochemical resin. These can be used alone or in combination. The thermoplastic resin can include additives, such as flame retardants, plasticizers, heat stabilizing agents and crystal nucleating agents, and polymer particles, such as non-crystalline resins, in addition to the polymers mentioned above. They can be used alone or in combination.

Specific examples of the polyolefin include, but are not limited to, polyethylene and polypropylene (PP, melting point 180 degrees C). They can be used alone or in combination.

Specific examples of polyamide include, but are not limited to, polyamide 410 (PA410), polyamide 6 (PA6), polyamide 66 (PA66, melting point 265 degrees C), polyamide 610 (PA610), polyamide 612 (pA612), polyamide 11 (PA11), polyamide 12 (PA12), semi-aromatic polyamide 4T (PA4T), polyamide MXD6 (Pa Mx D6), polyamide 6T (PA6T), polyamide 9T (PA9T, melting point 300 degrees C) and polyamide 10T (PA10T ). They can be used alone or in combination. PA9T is also called polynonamethylene terephthalic amide, consisting of a diamine having 9 carbon atoms and a monomer of terephthalic acid. In general, since the acidic side of carbon is an aromatic series, PA9T is called a semi-aromatic series. On the other hand, the polyamide in the present embodiment includes aramid formed by p-phenylenediamine and a terephthalic acid monomer as a complete aromatic series in which the diamine side is also aromatic.

Specific examples of polyester include, but are not limited to, polyethylene terephthalate (PET, melting point 260 degrees C), polybutadiene terephthalate (PBT, melting point 218 degrees C), and polylactic acid (PLA). In order to impart heat resistance, polyester including an aromatic series partially including terephthalic acid and isophthalic acid is also suitably used in the present embodiment.

Specific examples of the polyether include, but are not limited to, polyether ether ketone (PEEK, melting point 343 degrees C), polyether ketone (PEK), polyether ketone ketone (PEKK), polyaryl ether ketone (PAEK) , polyether ether ketone ketone (PEEKK) and polyether ketone ether ketone ketone (PEKEKK). In addition to the polyether mentioned above, crystalline polymers are also suitable. Specific examples include, but are not limited to, polyacetal, polyimide, and polyether sulfone. It is also suitable to use a polyamide having two melting peaks, such as PA9T (it is necessary to raise the temperature of a resin to the second or higher melting peak to fully melt the resin).

It should be noted that the column product may optionally contain a fluidizer, a granulating agent, a reinforcing agent, and an antioxidant. The proportion of the fluidizer is sufficient if it covers the surface of the particles and preferably 0.1 to 10 percent by mass relative to the column product. The inorganic particulate material having a volume average particle diameter less than 10 pm can be the fluidizer.

Powder properties

The solid free form manufacturing powder as an example of the powder containing the column product preferably satisfies at least one of the following ratios (1) to (3).

(1): Tmfl> Tmf2, where Tmfl represents the melting start temperature of the endothermic peak when the powder is heated to a temperature 30 degrees C higher than the melting point of the powder at a temperature rise rate of 10 degrees C per minute and Tmf2 represents the melting start temperature of the endothermic peak when the powder is heated to a temperature 30 degrees C higher than the melting point of the powder at a temperature rise rate of 10 degrees C per minute, it cools down to -30 degrees C or less at a rate of temperature decrease of 10 degrees C per minute and heated to the temperature of 30 degrees C above the melting point at a rate of temperature rise of 10 degrees C per minute and both Tmfl as Tmf2 are measured in a differential scanning calorimetry measurement according to ISO 3146. The melting start temperature of the endothermic peak represents a temperature at a point -15 mW lower than a straight line drawn parallel to the X axis from a place where the amount of heat becomes constant after the endotherm at the melting point ends on the lower temperature side.

(2): Cd1> Cd2, where Cd1 represents a crystallinity obtained from an amount of energy of the endothermic peak when the powder is heated to a temperature 30 degrees C higher than the melting point of the powder at a temperature rise rate of 10 degrees C per minute and Cd2 represents a crystallinity obtained from an amount of energy of the endothermic peak when the powder is heated to a temperature 30 degrees C higher than the melting point of the powder at a rate of temperature rise of 10 degrees C per minute, it is cooled down to -30 degrees C or less at a rate of temperature decrease of 10 degrees C per minute and heated to the temperature of 30 degrees C above the melting point at a rate of temperature rise of 10 degrees C per minute and both Cd1 and Cd2 are measured in a differential scanning calorimetry measurement according to ISO 3146.

(3): C x 1> C x 2, where C x 1 represents a crystallinity of the powder obtained by measuring X-ray diffraction and C x 2 represents a crystallinity obtained by measuring X-ray diffraction when the powder is Heats up to a temperature of 30 degrees C higher than its melting point at a temperature rise rate of 10 degrees C per minute, cools down to -30 degrees C or less at a temperature decrease rate of 10 degrees C per minute minute and subsequently heated to a temperature of 30 degrees C above the melting point at a rate of temperature rise of 10 degrees C per minute under nitrogen atmosphere.

Relationships (1) to (3) regulate the properties of the same powder for solid free form manufacturing from different points of view and are related to each other.

Measurement method of the melting start point of condition 1 according to the measurement by differential scanning calorimetry

The measurement method of the melt initiation temperature by differential scanning calorimetry (DSC) of the ratio (1) is based on the measurement method of ISO 3146 (plastic transition temperature measurement method, JIS K7121 format). A differential scanning calorimeter (for example, DSC-60A, manufactured by Shimadzu Corporation) is used to measure the melting onset temperature (Tmfl) of the endothermic peak when the powder is heated to a temperature of 30 degrees C above the point of melting of the same to a rate of elevation of temperature of 10 degrees C per minute. Subsequently, the powder is cooled down to -30 degrees C or less at a rate of decrease in temperature of 10 degrees C per minute and heated to the temperature of 30 degrees C above the melting point at a rate of temperature rise of 10 degrees C per minute to measure the melting start temperature (Tmf2) of the endothermic peak. The melting start temperature of the endothermic peak represents a temperature at a point -15 mW lower than a straight line drawn parallel to the X axis from a place where the amount of heat becomes constant after the endotherm at the melting point. It ends up on the lower temperature side.

Method of measuring the crystallinity of condition 2 according to the measurement by differential scanning calorimetry

The DSC crystallinity measurement method of condition (2) is based on the measurement method according to ISO 3146 (plastic transition temperature measurement method, JIS K7121 format) . The amount of energy (amount of heat of melting) of an endothermic peak when heated to a temperature of 30 degrees C above the melting point of the powder at a rate of temperature rise of 10 degrees C per minute is measured to obtain the crystallinity (Cd1) of the amount of heat of melting versus the amount of heat of complete crystallization. Subsequently, the powder is cooled down to -30 degrees C or less at a rate of decrease in temperature of 10 degrees C per minute and heated to the temperature of 30 degrees C above the melting point at a rate of temperature rise of 10 degrees C per minute to measure the amount of energy of the endothermic peak, so that the crystallinity (Cd2) can be obtained as the ratio of the amount of heat of melting against the amount of heat of complete crystallization.

Method of measuring crystallinity according to a ratio 3 X-ray analyzer

The crystallinity of the powder in ratio 3 is obtained by placing the powder on a glass plate to measure the crystallinity (C x 1) of the powder using an X-ray analyzer (for example, Discover 8, manufactured by Bruker Corporation) that includes a two-dimensional detector in a range of 20 from 10 to 40 at room temperature. Then, in the DSC, in a nitrogen atmosphere, the powder is heated up to 30 degrees C above its melting point at a rate of temperature rise of 10 degrees C per minute. The temperature is held for 10 minutes and the temperature of the powder (sample) returns to room temperature after cooling down to -30 degrees C at a rate of decrease in temperature of 10 degrees C per minute. Crystallinity (C x 2) can be measured just like C x 1.

Powder manufacturing method

In order to make the solid free-form manufacturing powder as an example of the powder, it is preferable to prepare a pellet, etc., containing the material that constitutes the solid free-form manufacturing particle in columnar fibrous material, unifying the fibrous material in column to obtain a unified material, cut the unified column material to obtain a cut product and shake the cut product.

In the fiber production step, it is preferable to extrude the resin molten liquid into a fibrous shape, while stirring the resin molten liquid at a temperature of 30 degrees C or higher than the melting point using an extruder. It is preferable to spread (stretch) the resin molten liquid to between about 1/1 and about 1/10 to obtain the fibrous form. The cross-sectional shape of the fiber depends on the shape of the extruder nozzle hole. For example, if the cross section is circular, the nozzle orifice is preferably circular. In this fiber production stage, the crystallinity of the resin can be controlled as described above.

In the unification process, a plurality of fibrous materials produced in the fiber production process are arranged side by side in the same direction for unification. As a method of unifying the fibrous materials, there is a method of unifying the materials in a sheet-like form by applying heat under pressure and a method of unifying the materials by adding water to the materials to cool them down to set. in ice. The method of unifying the materials into a sheet-like form by applying pressure and heat is preferable. At this stage, the fibrous material can be set. The heat applied depends on the type of resin used in bonding into a sheet-like form after the application of heat and pressure. The temperature is preferably the melting point thereof or lower and more preferably 100 degrees C lower than the melting point or higher. Furthermore, the applied pressure is preferably 10 MPa or less. The heat and pressure are preferably within the range in which each bonded fiber separates after the next cutting step. During "pressure heating", it is preferable, but not necessary, to apply heat and pressure at the same time. However, for example, it is possible to apply a pressure to the material in a state of residual heat which remains after the application of heat. Also, the unified material is not limited to a sheet-like shape if the next cutting step is properly processed. Also, the fiber arrangement direction is not necessarily complete, but substantially the same.

When the cross section of the shape of the fibrous material obtained in the fiber production process is a circle, the fibrous material is partially or totally transformed into a shape having a polygonal cross section. This enables a unified material to be produced in which a fibrous material having a polygonal cross section is unified.

In the cutting step, it is preferable to continuously cut the unified material made in the unification process to obtain a cut product. As a cutting device, it is possible to use, for example, a cutter employing a guillotine having an upper blade and a lower blade, a cutter employing a pressure cutting method using a lower plate and an upper blade and a cutter for cutting a material using CO2 laser beams, etc. The unified material is cut with such a cutter in such a way that the material can have a cutting surface perpendicular to the longitudinal direction of the fiber that forms the unified material. The cutting width of the cutting device is preferably 5.0 to 100.0 µm. Furthermore, the cutting speed of the cutting device is not particularly limited. For example, this is preferably 10 to 1,000 passes per minute (spm).

In the stirring process, it is preferable that the cut product produced in the cutting process is stirred to melt the surface due to mechanical friction to obtain a columnar product. As the stirring method, various spherical shaping methods, such as a method of collision of the cut products with each other and a method of collision of the cut product with a substance other than the cut product. However, the method is not limited to them. The number of rotations during stirring is preferably 500 to 10,000 rpm. The rotation time during stirring is preferably 1 to 60 minutes. Due to this process, the first peripheral area and the second peripheral area can be manufactured.

In these processes, since the unitized fibrous material is cut after the position and orientation of the unitized fibrous material are set, the cutting width and cutting direction of the solid free-form manufacturing resin can be uniform, obtaining , thus, columnar products that have a uniform shape. that is, as in the conventional method, in a method of fixing fibers with movable clamps, moving them to a cutting device and cutting the resin fibers to obtain powder, the fibers are not sufficiently fixed. Therefore, at the time of cutting, the fibers move during cutting, so that the cutting width and cutting direction vary. This variation in width of cut and direction of cut results in cut products having different sizes and shapes. Furthermore, for example, a massive amount of powder having an unexpected shape is produced due to the diagonal cutting of a resin having a cylindrical shape, as illustrated in the schematic diagram of FIG. 4. In the case of using such a cut product, since the solid shape is asymmetric, it is difficult to obtain a large number of columnar products having a shape in which one of the end surfaces partially covers the side surface, even after of the shaking treatment. Also, if the size of the cut product is uneven, the cut products are flattened by excessive force received in the stirring process, and in particular, large cut products, compared to other cut products, may not have the desired shapes. Therefore, in order to make the content (based on the number) of the column products to be 50 percent or more, it is preferable to undergo the fiber production process, the unification process, the cutting process and the stirring process described above, and it is more preferable to undergo a unification process of forming a sheet-like shape after applying heat under pressure.

Use of powder

The powder of the present embodiment achieves a proper balance between parameters such as granularity, particle size distribution, heat transfer properties, melt viscosity, bulk density, flowability, melting temperature. and the recrystallization temperature. This powder is suitably used in methods for making a solid free form fabrication using powder, such as SLS, SMS, multiple jet fusion (MJF), and binder injection (BJ). The powder of the present embodiment can be suitably used as a surface modifying agent, spacer, lubricant, paint, grinding stone, additive, secondary battery separator, food, cosmetics and clothing. Furthermore, it can be used as a material or replacement material for metals for use in fields such as automobiles, precision devices, semiconductor, aerospace industry, and medicine.

Device for crafting a solid freeform crafting object

The device for making a solid free-form fabricated object includes a layer-forming device for forming a layer including the powder for solid free-form fabrication and a casting device for melting the layer with electromagnetic irradiation, and further , may optionally include other devices.

Examples of the layering device include rollers, blades, brushes, etc., or combinations thereof.

Examples of the electromagnetic wave generator for use in a casting device are CO2 lasers, infrared radiation sources, microwave generators, radiant heaters, LED lamps, and combinations thereof.

The device for making a solid freeform fabrication object with the solid freeform fabrication powder is described with reference to FIG. 5. FIG. 5 is a schematic diagram illustrating the device for making a solid free-form fabricated object in accordance with one embodiment of the present disclosure.

As illustrated in FIG. 5, a solid free-form manufacturing device 1 includes a supply tank 11 as an example of the housing device for housing the resin powder P for manufacturing, a roller 12 for supplying the resin powder P housed in the supply tank 11 , a laser scanning space 13 where the resin powder P supplied by the roller 12 is arranged and scanning is carried out with a laser L, a source of electromagnetic irradiation 18 as a source of irradiation of the laser L as electromagnetic rays and a mirror of reflection 19 to reflect the laser L emitted from the electromagnetic irradiation source 18 to a predetermined position in the laser scan space 13. Furthermore, the solid free-form fabrication device 1 further includes heaters 11H and 13H for heating, respectively , the resin powder P in the supply tank 11 and the resin powder P housed in the laser scan space 13.

The reflecting surface of the reflection mirror 19 is moved based on two-dimensional data from a three-dimensional (3D) model, while the electromagnetic radiation source 18 emits the laser L. The two-dimensional data from the 3D model represents each cross-sectional shape for a 3D model cut with a predetermined interval. Therefore, when the angle of reflection of the laser L changes, the portion indicated by the two-dimensional data in the laser scan space 13 is selectively irradiated with the laser L. The resin powder located at the irradiation position of the laser L is melts and sinters to form a layer. That is, the electromagnetic irradiation source 18 serves as a layering device to form each layer of an object of manufacture from the resin powder P.

Furthermore, the supply tank 11 and the laser scan space 13 of the solid free-form manufacturing device 1 include, respectively, pistons 11P and 13P. The pistons 11P and 13P respectively move the supply tank 11 and the laser scan space 13 up and down against the rolling direction of the fabrication object upon completion of forming a layer. Because of this, new resin powder P for use in making a new layer can be supplied from supply tank 11 to laser scan space 13.

The solid free-form manufacturing device 1 changes the irradiation position of the laser by the reflection mirror 19 to selectively melt the resin powder P. The present disclosure is not limited thereto. The powder of the present embodiment can be suitably used in a manufacturing device employing a selective mask sintering (SMS) method. In the SMS method, for example, the resin powder is partially masked by a protective mask and the unmasked portion is irradiated with electromagnetic rays, such as infrared rays, so that the resin powder is selectively melted to obtain a manufacturing object. In the case of using the SMS process, the resin powder P preferably contains at least one of a heat absorber, dark material, etc. to strengthen the infrared absorption capacity. Examples of the heat absorber or dark material are carbon fiber, carbon black, carbon nanotube, and cellulose nanofiber. The SMS process that can be suitably used is described, for example, in US Patent Specification No. 6,531,086.

Manufacturing method of a solid freeform crafting object

The method of manufacturing a solid freeform fabrication object (3D modeling object) includes repeating a layering process to form a layer that includes the solid freeform fabrication powder and a casting process of the foundry of the layer with electromagnetic irradiation and, in addition, may optionally include other processes.

Examples of the layering step include forming a layer by means of a roller, a blade, a brush, or a combination thereof.

Examples of the casting step include casting with an electromagnetic radiation source, such as CO2 laser beams, an infrared radiation source, a microwave generator, a radiant heater, an LED lamp, and a combination thereof.

FIGS. 6 and 7 are concept diagrams illustrating a method of fabricating a solid free-form fabrication object. The method of manufacturing a solid freeform fabrication object using the solid freeform fabrication device 1 is described with reference to FIG. 6 and 7.

The heater 11H applies heat to the resin powder P housed in the supply tank 11. The temperature of the supply tank 11 is preferably as high as possible, but not higher than the melting point of the resin particle P, to reduce deformation that occurs during casting attributable to laser irradiation. However, in order to avoid melting of the resin powder P in the supply tank 11, the temperature is at least 10 degrees C lower than the melting point of the resin powder P. As illustrated in FIG. 6A, as an example of the supply process, the motor of the solid freeform making device 1 drives the roller 12 to supply the resin powder P in the supply tank 11 to the laser scan space 13 and level the laser scan space 13, thereby forming a powder layer having a thickness of T corresponding to the thickness of a single layer. The heater 13H applies heat to the resin powder P supplied to the laser scan space 13. The temperature of the laser scan space 13 is preferably as high as possible in order to reduce the deformation that occurs. produced during casting due to laser irradiation, but at least 5 degrees C lower than the melting point of the resin particle P, to avoid melting of the resin powder P in the laser scan gap 13.

The motor of the solid freeform fabrication device 1 receives input from multiple two-dimensional data created from the 3D model. As illustrated in FIG. 6B, the motor of the solid free-form manufacturing device 1 causes the electromagnetic irradiation source 18 to emit laser beams, while moving the reflection surface of the reflection mirror 19 based on the two-dimensional data for the part closest to the basis of an object of manufacture of the multiple two-dimensional data. The power of the laser has no particular limit and can be appropriately selected to suit a particular application. For example, this is preferably 10 to 150 W. Due to the laser irradiation of the powder layers, the resin powder P located corresponding to the pixel indicated by the two-dimensional data for the part closest to the base of a crafting object. At the end of the laser irradiation, the molten resin cures to form a sintered layer that has a shape in accordance with the two-dimensional data for the part closest to the base of an object of manufacture.

The thickness T of the sintered layer has no particular limit. For example, the average thickness T is preferably 10 µm or more, more preferably 50 µm or more, and even preferably 100 µm or more. The thickness T of the sintered layer has no particular limit. For example, the average is preferably less than 200 pm, more preferably less than 150 pm, and even preferably less than 120 pm.

As illustrated in FIG. 7A, in the formation of the sintered layer closest to the base, the motor of the solid freeform manufacturing device 1 reduces the laser scan gap 13 by an amount corresponding to the thickness T corresponding to the thickness of a single layer by the piston 13P to form a manufacturing space having a thickness T in the laser scan space 13. Furthermore, the motor of the solid free-form manufacturing device 1 raises the piston 11P to supply fresh resin powder P. Subsequently, as illustrated in FIG. 7A, the motor of the solid freeform manufacturing device 1 drives the roller 12 to supply the resin powder P from the supply tank 11 to the laser scan space 13 and level the laser scan space 13, thereby forming, a layer of powder having a thickness of T corresponding to the thickness of a single layer.

As illustrated in FIG. 7B, the motor of the solid free-form manufacturing device 1 causes the electromagnetic irradiation source 18 to emit laser beams, while moving the reflection surface of the reflection mirror 19 based on the two-dimensional data for the second closest layer based on multiple two-dimensional data. Due to the laser irradiation of the powder layers, the resin powder P located corresponding to the pixel indicated by the two-dimensional data for the second layer closest to the base melts. Upon completion of the laser irradiation, the molten resin is cured to form and laminate the sintered layer having a shape of the two-dimensional data for the second layer closest to the base into the sintered layer closest to the base.

The solid freeform fabrication device 1 repeats the supply process and the layering process to laminate the sintered layers. Upon completion of the fabrication based on the totality of the multiple two-dimensional data, a fabrication object is obtained that has the same shape as the 3D model.

Solid Freeform Fabrication Object

The solid freeform fabrication object can be suitably manufactured by the solid freeform fabrication method of the present disclosure.

Examples

Hereinafter, the present disclosure is described in detail with reference to, but is not limited to, Examples.

Example 1

A polybutylene terephthalate (PBT) resin (NOVADURAN® 5020, melting point 218 degrees C, glass transition temperature 43 degrees C, manufactured by Mitsubishi Engineering-Plastics Corporation) was stirred at a temperature of 30 degrees C higher. to the melting point thereof, and subsequently, the solid freeform manufacturing resin molten liquid was extruded (stretched) to give a fibrous shape using an extruder (manufactured by The Japan Steel Works, LTD.) having a die it had a circular hole. The fiber was adjusted to have a fiber diameter of 55 µm by stretching it 4 times. Subsequently, the formed fibers were arranged side by side in the same direction and a pressure of 10 MPa was applied, while heating to the temperature of 50 degrees C lower than the melting point to unify the fiber in one way. sheet type. The cross-sectional shape of each fiber unified in a sheet-like shape was substantially polygonal. Furthermore, the fibers unified in a sheet-like shape were cut in such a way that the cutting width was 50 pm and the cutting speed was 280 passes per minute (spm) using a push-type cutting device (type NJ Series 1200, manufactured by Ogino Seiki Co, Ltd.). Subsequently, in order to melt the surface by mechanical friction, it is treated the obtained cut product with a multi-purpose mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) at a rotational speed of 9,000 rpm for 20 minutes to obtain solid free form manufacturing resin powder. This was determined as the solid free form manufacturing resin powder of Example 1.

Example 2

The solid free form manufacturing resin powder of Example 2 was obtained in the same manner as in Example 1, with the exception that the time for stirring treatment in Example 1 using a multi-purpose mixer (manufactured by Nippon Coke & Engineering Co, Ltd.) was changed from 20 minutes to 10 minutes.

Example 3

The solid free form manufacturing resin powder of Example 3 was obtained in the same manner as in Example 1, except that the time for stirring treatment in Example 1 using a multi-purpose mixer (manufactured by Nippon Coke & Engineering Co, Ltd.) was changed from 20 to 5 minutes.

Example 4

The solid free form manufacturing resin powder of Example 4 was obtained in the same manner as in Example 3, except that the number of rotations for the stirring treatment in Example 3 using a multi-purpose mixer (manufactured by Nippon Coke & Engineering Co, Ltd.) was changed from 9,000 to 6,000 rpm.

Example 5

The solid free form manufacturing resin powder of Example 5 was obtained in the same manner as in Example 3, except that the number of rotations for the stirring treatment in Example 3 using a multi-purpose mixer (manufactured by Nippon Coke & Engineering Co, Ltd.) was changed from 9,000 to 3,000 rpm.

Example 6

A polybutylene terephthalate (PBT) resin (NOVADURAN® 5020, melting point 218 degrees C, glass transition temperature 43 degrees C, manufactured by Mitsubishi Engineering-Plastics Corporation) was stirred at a temperature of 30 degrees C higher. to the melting point thereof, and subsequently, the solid freeform manufacturing resin molten liquid was extruded (stretched) to give a fibrous shape using an extruder (manufactured by The Japan Steel Works, LTD.) having a die it had a circular hole. The fiber was adjusted to have a fiber diameter of 55 µm by stretching it 4 times. Subsequently, the formed fibers were arranged side by side in the same direction. Subsequently, water was applied to the fibers, which were then cooled to be fixed on ice. Furthermore, the ice-fixed fibers were cut in such a way that the cut width was 50 pm and the cut speed was 280 passes per minute (spm) using a push-type cutter (type nJ Series 1200, manufactured by Ogino Seiki Co, Ltd.). Subsequently, in order to melt the surface by mechanical friction, the cut product obtained was treated with a multipurpose mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) at a rotation speed of 9,000 rpm for 20 minutes to obtain powder. resin for solid free-form fabrication. This was determined as the solid free form manufacturing resin powder of Example 6.

Example 7

The solid free form manufacturing resin powder of Example 7 was obtained in the same manner as in Example 6, except that the number of rotations for the stirring treatment in Example 6 using a multi-purpose mixer (manufactured by Nippon Coke & Engineering Co, Ltd.) was changed from 9,000 to 3,000 rpm and the time for shaking treatment was changed from 20 to 5 minutes.

Example 8

The solid free form manufacturing resin powder of Example 8 was obtained in the same manner as Example 1, except that the polybutylene terephthalate (PBT) resin was exchanged for polyacetal (POM) resin (Jupital ® F10-01, melting point 175 degrees C, manufactured by Mitsubishi Engineering-Plastics Corporation).

Example 9

The solid free form manufacturing resin powder of Example 9 was obtained in the same manner as in Example 1, except that the polybutylene terephthalate (PBT) resin was exchanged for polyamide 12 (PA12) resin ( DADIAMID 12121, melting point 172 degrees C, manufactured by Daicel-Evonik Ltd.).

Example 10

The solid free form manufacturing resin powder of Example 10 was obtained in the same manner as Example 1, except that the polybutylene terephthalate (PBT) resin was exchanged for polyether ether ketone (PEEK) resin. (HT P22PF, melting point 343 degrees C, glass transition temperature 143 degrees C, manufactured by V iCt REX plc.).

Example 11

The solid free form manufacturing resin powder of Example 11 was obtained in the same manner as in Example 1, except that the polybutylene terephthalate (PBT) resin was exchanged for polypropylene (Pp) resin (NOVATEC ™ m A3, 180 degree C melting point, 0 degree C glass transition temperature, manufactured by JAPAN POLYPROPYLENE CORPORATION).

Example 12

A polybutylene terephthalate (PBT) resin (NOVADURAN® 5020, melting point 218 degrees C, glass transition temperature 43 degrees C, manufactured by Mitsubishi Engineering-Plastics Corporation) was stirred at a temperature of 30 degrees C higher. to the melting point thereof, and subsequently, the solid freeform manufacturing resin molten liquid was extruded (stretched) to give a fibrous shape using an extruder (manufactured by The Japan Steel Works, LTD.) having a die it had a circular hole. The fiber was adjusted to have a fiber diameter of 55 µm by stretching it 4 times. Subsequently, the formed fibers were aligned in the same direction and fixed with a movable clamp. Furthermore, the fibers fixed by the clamp were cut in such a way that the cutting width was 50 pm and the cutting speed was 280 passes per minute (spm) using a push type cutting device (type NJ Series 1200, manufactured by Ogino Seiki Co, Ltd.). Subsequently, in order to melt the surface by mechanical friction, the obtained cut product was treated with a multipurpose mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) at a rotation speed of 1,000 rpm for 20 minutes to obtain the resin powder for solid freeform fabrication. This was determined as the solid free form fabrication resin powder of Example 12.

Comparative Example 1

The solid free form manufacturing resin powder of Comparative Example 1 was obtained in the same manner as Example 1, except that the stirring treatment was not carried out for the polybutylene terephthalate (PBT) resin. in Example 1 using a multipurpose mixer (manufactured by Nippon Coke & Engineering Co., Ltd.).

Comparative Example 2

The solid free form manufacturing resin powder of Comparative Example 2 was obtained in the same manner as in Example 6, except that the stirring treatment was not carried out for the polybutylene terephthalate (PBT) resin. in Example 6 using a multi-purpose mixer (manufactured by Nippon Coke & Engineering Co., Ltd.).

Comparative Example 3

The solid free form manufacturing resin powder of Comparative Example 3 was obtained in the same manner as Example 12, except that the stirring treatment was not carried out for the polybutylene terephthalate (PBT) resin. in Example 12 using a multipurpose mixer (manufactured by Nippon Coke & Engineering Co., Ltd.).

Regarding the solid free form manufacturing resin powder obtained in each Example and each Comparative Example, the powder form was observed as follows, and the content of the column products and the shortest length of the first column were measured. peripheral area and the second peripheral area. The results are shown in Table 1.

Powder form

The resin powder obtained for solid free form fabrication was photographed at a magnification power of 150 x using a SEM (JSM-7800 FPRIME, manufactured by JEOL Ltd.). In the solid free-form manufacturing resin powder in the SEM image thus obtained, the powder determined as columnar product had a first surface, a second surface, and a side surface and had at least one of the peripheral area of the first surface. and the peripheral area of the second surface that extended partially or fully along the lateral surface in the area observed by SEM.

Next, the side face of the solid free form manufacturing powder determined as column product was observed. When the powder was observed to have multiple surfaces segmented by lines (corners) in the height direction of the columnar product, the first opposing surface and the second opposing surface were determined to be substantially polygonal. When the powder was found to have a uniformly smooth surface with no lines in the height direction of the columnar product, the first opposing surface and the second opposing surface were determined to be substantially circular (substantially perfectly circular or substantially ellipsoidal).

Particle ratio for solid free form fabrication (column product)

The resin powder obtained for solid free form fabrication was photographed at a magnification power of 150 x using a SEM (JSM-7800 FPRIME, manufactured by JEOL Ltd.). In the solid free-form manufacturing resin powder in the SEM image thus obtained, the powder determined as columnar product had a first surface, a second surface, and a side surface and had at least one of the peripheral area of the first surface. and the peripheral area of the second surface that extended partially or fully along the lateral surface in the area observed by SEM.

Then, from the SEM image, the number of the resin powder for making solid free form and the number of the column products were obtained. The proportion (percent) based on the number of the column product was calculated by dividing the number of column products by the number of resin powder for making solid free form, followed by multiplication by 100. In addition, when counted the number of resin powder for solid free-form manufacturing and the number of column products from the SEM image, only the powder for solid free-form manufacturing and the column product that had a longer part of 20 pm or more. In addition, the number of the solid free form manufacturing resin powder was 100 to calculate the proportion of the column product.

Shortest length of the peripheral area of the first surface and the second surface

The resin powder obtained for solid free form fabrication was photographed at a magnification power of 150 x using a SEM (JSM-7800 FPRIME, manufactured by JEOL Ltd.). In the solid free-form manufacturing resin powder in the SEM image thus obtained, the powder determined as columnar product had a first surface, a second surface, and a side surface and had at least one of the peripheral area of the first surface. and the peripheral area of the second surface that extended partially or fully along the lateral surface in the area observed by SEM.

Next, the shortest lengths (pm) of the peripheral area of the first area and the peripheral area of the second peripheral area in the column product height direction were calculated for the column product in the area observed by SEM.

Table 1

continuation

In each of the solid free form manufacturing resin powder obtained in each Example and each Comparative Example, the uncompacted density, volume average particle diameter Dv, number average particle diameter were evaluated as follows. Dn and the resistance of the manufactured object. Results are shown in table 2.

Uncompacted density

The uncompacted density of the resin powder prepared for solid free form fabrication was measured using a bulk density measuring instrument (according to the JIS Z-2504 format, manufactured by "Kuramochi Kagaku Kikai Seisakusho") and the uncompacted density The measurement was divided by the actual density of each resin to determine the uncompacted fill ratio (percent). Grades C or higher are assessed as practical.

Evaluation criteria

A: 40 percent or more

B: 35 percent to less than 40 percent

C: 33 percent to less than 35 percent

D: Less than 33 percent

Volume average particle diameter Dv and number average particle diameter Dn

The volume average particle diameter Dv (pm) of the resin powder thus obtained for solid free form fabrication was measured using a particle size distribution measuring instrument (Microtrac MT 3300EXII, manufactured by MicrotracBEL Corp. ) using a drying process method (atmosphere) without using a solvent, using a refractive index of the particles for each resin powder.

The number average particle diameter Dn (pm) of the resin powder thus obtained for solid free form fabrication was measured using a particle size distribution measuring instrument (F-PIA 3000, manufactured by Sysmex Corporation).

Furthermore, the ratio (Dv / Dn) of the volume average particle diameter Dv / number average particle diameter Dn was calculated from the number average particle diameter Dn and the volume average particle diameter Dv obtained.

Manufacturing object strength

The resin powder thus obtained for solid free-form fabrication was added to the supply bed of a fabrication device by the SLS method (AM S5500P, manufactured by Ricoh Company, Ltd.) to fabricate a solid free-form fabrication object. . The setting conditions were: 0.1 mm average layer thickness, 10 to 150 W laser output, 0.1 mm laser scan gap, and -3 degrees C workpiece bed temperature below the melting point. In the fabrication device by the SLS method, five tensile test specimens (fabrication object in XY) were fabricated which had a long side oriented in the direction of the XY plane (direction of the plane in which the roller 12 advances in FIG. 5) and five tensile test specimens (Z-fabricated object) having a long side oriented in the direction of the Z-axis (direction perpendicular to the plane in which the roller 12 advances in FIG. 5) in the central part of the laser scan space 13. The space between each fabrication object was 5mm or more. As the tensile test sample, the polyvalent canine bone type test sample of ISO (International Organization for Standardization) 3167 Type 1A was used (the sample has a central portion of a length of 80 mm, a thickness of 4 mm and a width of 10 mm). The manufacturing time was set at 50 hours.

Next, using the same solid freeform fabrication resin powder, five tensile test specimens were molded in the same shape by injection molding.

For the XY fabrication object and the Z fabrication object such as tensile test specimens obtained by the fabrication device by the SLS method and tensile test specimens obtained by injection molding, a test equipment of Tensile (AGS-5 kN, manufactured by Shimadzu Corporation) in accordance with ISO 527 for measuring tensile strength. The test speed in the tensile strength test was constant at 50 mm / minute. The tensile strength was determined as the average value of the measured values obtained by the test carried out five times for each tensile test sample. Subsequently, the tensile strength of the tensile test sample obtained by the manufacturing device by the SLS method was divided by the tensile strength of the tensile test sample obtained by injection molding to evaluate the resistance to the tensile strength of the tensile test specimen obtained by the fabrication device by the SLS method.

The case was considered practical where both the XY fabrication and Z fabrication evaluations were equal to or greater than 60 percent of the injection molded product.

Table 2

Having now fully described the embodiments of the present invention, it will be apparent to one skilled in the art that many changes and modifications can be made therein without departing from the scope of the appended claims.

Claims (15)

1. A polymer particle (21) having a columnar shape having end surfaces (22a, 23a) and a lateral surface (24), wherein the particle comprises at least one perimeter area (22b; 23b) which is substantially orthogonal and continuous with one of the end surfaces (22a, 23a) through a curved surface to partially cover the side surface (24). 2. The polymer particle (21) according to claim 1, wherein the at least one perimeter area (22b, 23b) covers an entire circumference of the lateral surface (24). The polymer particle (21) according to claims 1 or 2, wherein the particle (21) comprises first and second perimeter areas (22b, 23b). 4. A powder comprising: the polymer particle (21) of any one of claims 1 to 3. 5. The powder according to claim 4, wherein the minimum length of the at least one perimeter area (22b; 23b) in a height direction of the columnar shape of the polymer particles (21) is al minus 1 pm. The powder according to claim 4 or 5, wherein the polymer particle (21) represents 50 percent or more of the powder based on the number. The powder according to any one of claims 4 to 6, wherein the polymer particle (21) represents 70 percent or more of the powder based on the number. The powder according to any one of claims 4 to 7, wherein the end surfaces (22, 23) of the polymer particles (21) are substantially circular, substantially ellipsoidal or substantially polygonal. 9. The powder according to any one of claims 4 to 8, wherein the polymer particle (21) is substantially prismatic. The powder according to claim 9, wherein the polymer particle (21) that is substantially prismatic represents 40 percent or more of the powder based on the number. The powder according to any one of claims 4 to 10, wherein the powder is suitable for use in a solid free-form manufacturing process to form a solid free-form manufacturing object. 12. A system comprising a device (1) for making a solid freeform fabrication object and the powder of claim 11; understanding the device: a housing device (11) configured to house the powder of claim 11; a layering device (12; 18) configured to form a layer comprising the powder of claim 11; Y a casting device (18) configured to cast the layer with electromagnetic irradiation. 13. A method of fabricating a solid free-form fabricated object, comprising: forming a layer comprising the powder of claim 11; Y melt the layer by electromagnetic irradiation. 14. A method of manufacturing a solid free-form manufacturing powder, comprising: forming a material that constitutes the powder in fibrous materials; unifying the fibrous materials arranged side by side in the same direction to form a unified material, the unification method comprising applying heat under pressure or adding water to the materials to cool them until they are fixed in ice; cutting the unified material to obtain a cut product; Y shake the cut product. The method according to claim 14, wherein the fibrous materials are heated under pressure in bonding.