KR20170020296A - Forming materials and method for 3D printing based on irregular shape amorphous glass and structure body thereby - Google Patents

Abstract

The present invention relates to a molding material for 3D printing which is based on amorphous glass having an irregular shape in powder form, and yet achieves excellent fluidity and sintering properties which enable rapid molding of high-quality products; to a molding method for 3D printing; and to a molded body. The molding material for 3D printing comprises: a glass powder base which is formed by crushing amorphous glass to be an unmelted, irregularly shaped powder; a spherical nanopowder which has an average particle diameter smaller than 1/50 of the average particle diameter of the glass powder base and is mixed with the glass powder base and disposed on the surface of the glass powder base, thereby increasing the fluidity of the irregularly shaped glass powder base when molding through 3D printing.

Description

TECHNICAL FIELD [0001] The present invention relates to a molding material for 3D printing based on a crushed irregular shaped amorphous glass, a molding method and a molding body for 3D printing,

The present invention relates to a 3D printing technology, and more particularly, to a 3D printing method and a 3D printing method which are capable of rapidly forming a high-quality article by securing excellent fluidity and sinterability based on powdery amorphous glass having a crushed and irregular shape, And a molding method and a molded body for 3D printing.

In general, 3D (3-dimensional, 3-dimensional) printing technology is a technique for producing a three-dimensional object by stacking layers with a small thickness using ink of a special material. 3D printing technology has been widely used in various fields and has been widely used for various models such as a medical human body model, a household toothbrush such as a toothbrush or a razor, as well as an automobile field composed of many parts.

Currently, the most commonly used material for 3D printing is photopolymer, a photocurable polymer material that solidifies when exposed to light, accounting for more than 50% of the entire market. The next most popular material is solid, thermoplastic, which is free to melt and solidify. It occupies 40% of the market, and metal powder is expected to grow gradually. The shape of the double thermoplastics material may be in the form of filaments, particles or powder powders. It is known that 3D printing using a filament type material is faster than other types in terms of speed, which is advantageous in productivity. Examples of such filament materials include polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), high density polyethylene (HDPE) and polycarbonate (PC). That is, first, since the melting point is moderately high, the solidification rate is fast after printing, so that even if the printing speed is fast, it is not deformed, and dimension and shape stability are good. Second, since the melting point is moderately low, the extrusion is easy and the production efficiency is high when the filament is manufactured. In addition, if the melting point is too high, it is necessary to dissolve the filament, which consumes a lot of electric power, and the parts in the printer must be made of a material capable of withstanding high temperatures.

However, the currently used 3D printing materials are limited to photopolymers and thermoplastics, which are mainly focused on the formability. Therefore, research and development of a variety of materials are urgently needed. Particularly, it is required to develop a material for 3D printing which is capable of forming an article smoothly for 3D printing, but which can be combined with various mechanical characteristics while having light transmittance and hardness, which are imposed on photopolymers or thermoplastics .

Korean Registered Patent No. 1394119 (Apr.

Accordingly, it is an object of the present invention to provide a 3D printing technique, and more particularly, to a 3D printing technique which is based on powdery amorphous glass having a crushed and irregular shape, And to provide a molding material for 3D printing, a molding method for 3D printing, and a molded article, which are capable of rapidly molding a high-quality article by securing excellent fluidity and sintering property.

Technical Solution According to an aspect of the present invention, there is provided a molding material for 3D printing, comprising: a base glass powder formed to have an irregular shape in an amorphous glass state; And a spherical nano powder having an average particle diameter smaller than 1/50 of the average particle diameter of the parent material glass powder and mixed to be positioned on the surface of the parent material glass powder to improve the fluidity of the parent material glass powder having an irregular shape when formed by 3D printing As a technical feature.

Here, the base material glass powder is composed of a glass composition system in which the main component is SiO ₂ , a glass composition system in which the main component is Bi ₂ O ₃ , a glass composition system in which the main component is P ₂ O ₅ , a glass composition system in which the main component is V ₂ O ₅ , , And a glass composition system whose main component is TeO ₂ .

The average particle diameter of the base glass powder is in the range of 1 to 200 mu m, and the average particle diameter of the spherical nano powder is 100 nm or less.

The average particle diameter of the spherical nano powder to the base material glass powder may be in the range of 1/200000 to 1/50.

In addition, the base glass powder may be characterized in that the glass is first crushed by ball milling to form a coarse powder, followed by secondary crushing by jet milling or ball milling to form a fine powder.

In addition, the material of the spherical nano powder is a glass composition system in which the main component is SiO ₂ , a glass composition system in which the main component is Bi ₂ O ₃ , a glass composition system in which the main component is P ₂ O ₅ , a glass composition system in which the main component is V ₂ O ₅ , the glass in composition, whose main component is or belongs to any one of TeO ₂ glass in composition, SiO _2, Y ₂ O _3, Al ₂ O _3, TiO _2, ZrO, NiO, CoO, CeO _2, MgO, CaO, WO _3, CuO, and Fe ₂ O ₃ as main components.

The spherical nano powder may have a glass transition temperature lower than a glass transition temperature of the base glass powder, thereby promoting sintering of the base glass powder.

In addition, the material of the spherical nano powder is a glass composition system in which the main component is SiO ₂ , a glass composition system in which the main component is Bi ₂ O ₃ , a glass composition system in which the main component is P ₂ O ₅ , a glass composition system in which the main component is V ₂ O ₅ , , And a glass composition system having a main component of TeO ₂ , which is a multi-component oxide glass.

In addition, the average particle diameter of the base glass powder is in the range of 1 to 200 mu m, and the spherical nano powder has an average particle diameter of 10 nm or less.

In addition, the spherical nano-powder may be formed of SiO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , NiO, CoO, CeO ₂ , MgO, CaO, WO ₃ , CuO, Fe ₂ O ₃ A single oxide having an average particle diameter of 100 nm or less is mixed with the glass powder to increase the molding strength of the base glass powder.

The spherical nano powder may be formed of any one of the single oxides which do not react with the base glass powder during the sintering of the base glass powder to increase the molding strength together with the fluidity of the base glass powder. can do.

Furthermore, said spherical nano-powder is _{SiO 2, Y 2 O 3,} Al 2 O 3, TiO 2, ZrO, NiO, CoO, CeO 2, MgO, CaO, WO 3, CuO, Fe 2 O 3 And a single oxide having an average particle size of 100 nm or less.

The spherical nano powder may be dispersed on the surface of the base glass powder by heat and static electricity.

The sintering of the green body in the sintering step may be performed at a temperature in a range between a maximum shrinkage temperature and a softening temperature of the base glass powder.

Also, the spherical nano powder may be mixed at a mixing ratio ranging from 0.01 vol% to 1 vol% relative to the whole.

Meanwhile, the 3D printing forming method according to the present invention comprises: a crushing step of crushing an amorphous glass to produce a base glass powder having an irregular shape in an unmelted powder state; Mixing a spherical nano powder having an average particle size smaller than 1/50 of the average particle size of the base glass powder as a fluidity improving material for improving fluidity of the base glass powder; A molding step of molding a 3D formed body using a mixed powder in which the base glass powder and the spherical nano powder are mixed; And a sintering step of sintering the formed body molded in the molding step.

Here, in the crushing step, the glass is first crushed by ball milling to form a coarse powder, followed by secondary crushing by jet milling or ball milling to sequentially form fine powder to form the base glass powder . ≪ / RTI >

Further, the amorphous glass before crushing may be characterized in that the melted glass material is a cullet thinned by being poured into a ribbon roller.

Also, in the mixing step, the spherical nano powder may be coated on the surface of the base glass powder in a dispersed state.

The base glass powder and the spherical glass powder may be mixed by dry mixing.

Between the molding step and the firing step, a drying step of drying the molded body and a powder washing step of removing the powder remaining on the molded body may be performed.

Also, a binder removing step of burning and removing the binder used in the forming step is performed between the molding step and the firing step, and the removal temperature of the binder is lower than the glass transition temperature of the base material glass powder. can do.

The spherical nano powder may have a glass transition temperature lower than a glass transition temperature of the base glass powder, thereby promoting sintering of the base glass powder.

Meanwhile, the method of forming a bio-sheath-mimetic 3D molded article according to the present invention is characterized in that a plurality of voids are formed in the molding step so as to have translucency and light weight.

At least one layer is formed into a porous layer formed with a plurality of voids, and at least one layer including a layer adjacent to the porous layer is formed into a fibrous layer having superposed linear unit structures . ≪ / RTI >

In addition, the linear unit structures may be characterized in that they are at least partly cross-arranged.

Further, the linear unit structures in the upper layer of the fibers may be formed into a superposed shape while partially forming fine gaps with each other.

Further, the layer adjacent to at least one of the upper layer and the porous layer may be formed into a layer of scales in which plate-like unit structures are partially folded in a scaly shape.

In addition, the molded article according to the present invention is characterized by being a molded body for 3D printing, which has a light-transmitting property and light weight, formed by forming a plurality of voids.

At least one of the layers other than the porous layer is a fibrous upper layer formed in a shape in which linear unit structures are superimposed on one another. .

The forming material for 3D printing and the forming method for 3D printing according to the present invention are able to realize a molding material for 3D printing by securing excellent fluidity based on powdery amorphous glass having an irregular shape which is crushed.

Further, the present invention is capable of rapidly molding a high-quality article through improved sinterability and molding strength as well as excellent flowability.

1 is a micro-photograph of a molding material for 3D printing according to an embodiment of the present invention;
2 is a photograph of a spherical nano powder coated on the surface of a base glass powder in a molding material for 3D printing according to an embodiment of the present invention
FIGS. 3A to 3G are a series of graphical representations for explaining the effect of the spherical nano powder on the base glass powder in the molding material for 3D printing according to the embodiment of the present invention
4 is a flowchart for explaining a 3D printing forming method according to an embodiment of the present invention.
5 is a longitudinal sectional view for explaining a bio-sheath type mimetic 3D molded article according to an embodiment of the present invention
6 is a cross-sectional enlarged view of a scale layer, a fibrous layer, and a porous layer for explaining the constitution of a bio-sheath mimetic 3D molded article according to an embodiment of the present invention
FIGS. 7 and 8 are enlarged views illustrating a detailed configuration of a molded body of a bio-sheath type mimetic 3D formed body according to an embodiment of the present invention
9 is a comparative photograph of a molded body showing the surface characteristics of a molded body according to mixing of spherical nano powder in a molded material
Fig. 10 is a photograph of a sintered body obtained by sintering a molded body obtained by using only base glass powder without spherical nano powder at a maximum shrinkage temperature and a softening point, and a shrinkage ratio graph
11 is a photograph of a sintered body obtained by sintering a molded body obtained by adding spherical nano powder to a base glass powder at a maximum shrinkage temperature,
12 is a photograph showing a state in which spherical nano powder is uniformly dispersed and coated on the surface of the base material glass powder
13 is a conceptual diagram for explaining the phenomenon that the spherical nano powder reduces the cohesive force between the parent glass powders by increasing the particle spacing between the parent glass powders

A molding material for 3D printing, a molding method for 3D printing, and a molded article according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are enlarged to illustrate the present invention, and are actually shown in a smaller scale than the actual dimensions in order to understand the schematic structure.

Also, the terms first and second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. On the other hand, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

FIG. 1 is a photograph of a molding material for 3D printing according to an embodiment of the present invention, and FIG. 2 is a graph showing a relationship between a spherical nano powder coated on a surface of a base glass powder in a molding material for 3D printing according to an embodiment of the present invention . 3A to 3G are a series of reference views for explaining the effect of the spherical nano powder on the base glass powder in the molding material for 3D printing according to the embodiment of the present invention.

1 and 2, a molding material for 3D printing according to an embodiment of the present invention includes a base glass powder 10 formed to have an irregular shape in a powder state in which amorphous glass is crushed and not melted, Glass powder 10 having an average particle diameter smaller than 1/50 of the average particle diameter of the glass powder 10 and mixed to be positioned on the surface of the base material glass powder 10 so that the fluidity of the base material glass powder 10 having an irregular shape during 3D- And a spherical nano powder 20 for increasing the particle diameter. Referring to FIG. 1, it can be seen that most of the parent glass powders 10 having an irregular shape are mixed in a mostly angular form. In FIG. 2, which is partially enlarged, nano-sized glass powders 10 on the surface of the mixed parent glass powder 10 (Spherical nano powder 20 is used as spherical nano powder 20) is dispersed and coated.

It can be noted that in the case of the molding material for 3D printing according to the embodiment of the present invention, the crushed glass powder having an angular shape and an irregular shape is used as a base material. As is known, in the case of molding materials for 3D printing up to now, mainly focusing on the possibility of molding to form a specific article has been focused on. In particular, when the powder material is used, the fluidity of the powder is regarded as an important variable The use of the angular form of powder, which is believed to impair fluidity, such as crushed glass powder, was considered to be extremely reckless. However, in the case of the molding material for 3D printing according to the embodiment of the present invention, the general prejudice is boldly overcome, so that even if glass powder having an irregular shape is used as a base material in most angular shapes, the spherical shape having a finer nano- It has been found that sufficient fluidity can be secured for 3D printing if the nanopowder 20 is dispersed and coated so that the glass powder 10 having irregular shapes is mixed with the spherical nanopowder 20 A molding material for 3D printing is proposed. Of course, this is followed by various conditions and specific configurations, which will be described in more detail below.

The base glass powder 10 is a base material for the 3D printing and is formed to have an irregular shape in a powder state in which the amorphous glass is crushed and unmelted as described above. As the material of the base glass powder 10, a glass composition system in which the main component is SiO ₂ , a glass composition system in which the main component is Bi ₂ O ₃ , a glass composition system in which the main component is P ₂ O ₅ , a glass composition system in which the main component is V ₂ O ₅ , A glass composition system whose main component is PbO, and a glass composition system whose main component is TeO ₂ can be used.

The average particle size of the base glass powder 10 is preferably in the range of 1 to 200 mu m. In this regard, the smaller the particle diameter of the base glass powder 10 is, the more advantageous for molding an article that is precise and unbonded. However, the smaller the particle size, the lower the fluidity between the powders. Therefore, the base glass powder 10 is preferably prepared to have an average particle diameter in the range of 1 to 200 mu m. At this time, in the case of the nano powder to be dispersedly coated on the surface of the base glass powder 10, it can be flexibly prepared to have a size suitable for the size of the base glass powder 10, and if it is prepared below 100 nm, And it is possible to prepare it with a smaller size. In order to prepare the base glass powder 10, it is necessary to melt the glass raw material so that the melt is poured onto the ribbon rollers to make a thin cullet so that the crushing can be smoothly performed. Thereafter, . That is, primary pulverization is performed by ball milling to form a coarse powder, and then secondary pulverization is performed by jet milling (jet milling is preferable but ball milling is also possible) which can be crushed to a smaller particle size to form a fine powder. Thus, it is possible to prepare a base glass powder 10 having a more uniform particle size by making a cullet made of amorphous glass and crushing the cullet in a step-by-step manner.

For reference, it is also conceivable to purchase spherical nano-sized glass particles from the beginning without performing the above-mentioned crushing process in order to prepare the base glass powder 10 as described above. However, Is sublimated at a high temperature and then instantaneously cooled to obtain spherical powder. As a result, it is practically impossible to provide a large amount of base glass powder 10 having a micro-unit size. On the other hand, when the base glass powder 10 has a nano-size, cohesion between powders is strong, and it is impossible to secure the fluidity necessary for molding.

The spherical nano powder 20 plays a role to increase fluidity which is the maximum difficulty of the base glass powder 10 having an irregular shape. For this, the spherical nano powder 20 is mixed so as to be located on the surface of the base glass powder 10 with an average particle diameter smaller than 1/50 of the average particle diameter of the base glass powder 10, as described above. In the enlarged photograph of FIG. 2, it can be seen that the spherical nano powder 20 is coated on the surface of the base glass powder 10 in a dispersed state. In order for the spherical nano powder 20 to be uniformly dispersed on the surface of the base glass powder 10, an average particle size of less than 100 nm, which is comparatively very small as compared with the base glass powder 10 By weight based on the total mixed powder and mixing at a mixing ratio falling within the range of 0.01 vol.% To 1 vol.%.

When the spherical nano powder 20 is coated on the surface of the base glass powder 10 in a dispersed state, the spherical nano powder 20 prevents direct contact between the base glass powders 10 as shown in FIG. 3A, 3b and 3c, when the force to flow to the base glass powder 10 is applied, it acts as a bearing therebetween to improve the fluidity.

As the material of the spherical nano powder 20, a glass composition system in which the main component is SiO ₂ , a glass composition system in which the main component is Bi ₂ O ₃ , a glass composition system in which the main component is P ₂ O ₅ , a glass composition system in which the main component is V ₂ O ₅ , A glass composition system of PbO, and a glass composition system whose main component is TeO ₂ . According to the material of the spherical nano powder 20, the same material as that of the parent material glass powder 10 can be provided. In this case, there is no contamination of the parent material glass powder 10, There is no problem in securing the transmittance due to the light. If the glass transition temperature of the spherical nano powder 20 is lower than the glass transition temperature of the base glass powder 10, the spherical nano powder 20 may have an irregular fluidity of the base glass powder 10 But also serves as a sintering accelerator. That is, as shown in FIGS. 3D to 3G, the spherical nano powder 20 having a small particle size during sintering is first sintered, and the sintering of the surface of the base glass powder 10, which is in contact with the spherical nano powder 20, As the sintering of the base glass powder 10 proceeds from the early stage, the time required for the entire sintering can be shortened. In order to accelerate sintering, it is preferable that the spherical nano powder 20 has an average particle diameter of 10 nm or less.

On the other hand, the spherical nano powder 20 is _{SiO 2, Y 2 O 3,} Al 2 O 3, TiO 2, ZrO, NiO, CoO, CeO 2, MgO, CaO, WO 3, CuO, Fe 2 O 3 And a single oxide having an average particle diameter of 100 nm or less. When such spherical nano powder 20 is provided with such materials, it plays a role of enhancing fluidity of the base glass powder 10, while it does not react with the base glass powder 10 during sintering, .

In addition, the material of the spherical nano powder 20 is a glass composition system in which the main component is SiO2, a glass composition system in which the main component is Bi2O3, a glass composition system in which the main component is P2O5, a glass composition system in which the main component is V2O5, a glass composition system in which the main component is PbO, SiO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , NiO, CoO, CeO ₂ , MgO, CaO, WO ₃ , CuO, Fe ₂ O ₃ Or a single oxide of any one of them may be combined. When the spherical nano powder 20 thus mixed with the base glass powder 10 is mixed with the base glass powder 10, sintering can be promoted and the molding strength can be increased at the time of sintering as well as the fluidity of the base glass powder 10 is improved. Both of these materials mainly serve to improve the fluidity of the base glass powder (10) and promote the sintering and improve the molding strength. Therefore, it is necessary to increase the content in order to increase the weight of the sintering promotion and the improvement of the molding strength .

In Table 1 below, the materials according to the function of the spherical nano powder 20 described above are classified and arranged.

function Furtherance Spec. Improved liquidity The main component is SiO ₂ glass in composition, whose main component is a Bi ₂ O ₃ in the glass in composition, whose main component is P ₂ O ₅ in the glass in composition, whose main component is V ₂ O ₅ in the glass in composition, the main component is PbO glass in composition, the main component TeO ₂ of A multi-component oxide glass belonging to any one of the glass composition systems - spherical particles
- 100 nm or less Improve fluidity + promote sintering The main component is SiO ₂ glass in composition, whose main component is a Bi ₂ O ₃ in the glass in composition, whose main component is P ₂ O ₅ in the glass in composition, whose main component is V ₂ O ₅ in the glass in composition, the main component is PbO glass in composition, the main component TeO ₂ of A multi-component oxide glass belonging to any one of the glass composition systems - spherical particles
- 10 nm or less
- basically a composition having a glass transition temperature lower than the glass transition temperature of the base glass powder (10) Improved fluidity + Improved molding strength _{SiO 2, Y 2 O 3,} Al 2 O 3, single oxides of _{TiO 2, ZrO, NiO, CoO} , CeO 2, MgO, CaO, WO 3, CuO, Fe 2 O 3 - spherical particles
- 100 nm or less Improvement of fluidity + Promotion of sintering + Improvement of molding strength The main component is SiO ₂ glass in composition, whose main component is a Bi ₂ O ₃ in the glass in composition, whose main component is P ₂ O ₅ in the glass in composition, whose main component is V ₂ O ₅ in the glass in composition, the main component is PbO glass in composition, the main component TeO ₂ of glass multi-component oxide glass belonging to any one of the in composition _{+ SiO 2, Y 2 O 3} , Al 2 O 3, TiO 2, ZrO, NiO, CoO, CeO 2, MgO, CaO, WO 3, CuO, Fe 2 O 3 Single oxide of In the case of the multi-component oxide glass, the spherical particles having a particle size of 10 nm or less have a glass transition temperature lower than the glass transition temperature of the base glass powder (10)
In the case of a single oxide,

Next, a 3D printing molding method according to an embodiment of the present invention based on the above-described molding material for 3D printing will be described below.

4 is a flowchart illustrating a 3D printing forming method according to an embodiment of the present invention.

As shown in the drawings, the 3D printing forming method according to an embodiment of the present invention includes a cull forming step, a primary crushing step, a secondary crushing step, a mixing step, a molding step, a drying step, a powder washing step, a binder removing step, .

In such processes, a molding material for 3D printing of a unique shape is prepared through the culling step, the primary crushing step, the secondary crushing step, and the mixing step, and then the molding material is subjected to a molding step, a drying step, A binder removal step, and a firing step. Hereinafter, a 3D printing molding method according to an embodiment of the present invention will be described in more detail with reference to the above steps.

First, in the cullet-forming step, the glass raw material powder is precisely weighed and mixed according to the composition, and is melted, and the melted material is poured into a ribbon roller to form a thin cullet. The glass material is SiO _2, Bi ₂ O _3, P ₂ O _5, V ₂ O _5, PbO, TeO to as a main component any one of a _second main component is SiO _2, the glass in composition, whose main component is Bi ₂ O ₃ in the glass in composition , A glass composition system whose main component is P ₂ O ₅ , a glass composition system whose main component is V ₂ O ₅ , a glass composition system whose main component is PbO, and a glass composition system whose main component is TeO ₂ .

Thereafter, the primary crushing step proceeds. In the primary crushing step, the cullet made in the previous step is crushed first to make a crush powder (RC powder). For this purpose, a ball miller is used. The size of the glass powder obtained through this step is preferably about 15 mu m as the minimum size of the glass powder. In order to obtain fine particles having a smaller size, the ball milling process time must be long. However, there is a problem that the contamination becomes worse as the process time becomes longer (ZrO and Al ₂ O ₃ balls are used. So that contaminants are generated). Therefore, a jet milling process should be used to prepare a glass powder having a smaller size. For reference, if the contamination becomes worse, the light transmittance becomes poor after sintering of the glass powder.

Thereafter, the second crushing step proceeds. In the secondary crushing step, glass finely divided by secondary milling by jet milling (or ball milling). The jet milling process is a process of blowing a jet stream to induce the breakdown of the particles in a manner that causes a collision between coarse particles obtained in the previous step, and a coarse particle size of 15 μm has a minimum size of 2 to 3 μm More finely crushed by differential. Thereby, the base glass powder 10 having an irregular shape in an unmelted powder state is obtained.

Thereafter, the mixing step proceeds. In the mixing step, the base glass powder 10 and the spherical nano powder 20 are mixed. For this purpose, the spherical nano powder 20 of 0.01 vol.% To 1 vol.% Is mixed with the base glass powder 10 and subjected to a dry mixing process using a tubular mixer for about 4 hours. The spherical nano powder 20 used here is a glass composition system in which the main component is SiO ₂ when the fluidity of the base glass powder 10 is mainly intended to be improved, the main component is Bi ₂ O ₃ glass composition system, the glass having the main component P ₂ O ₅ A spherical particle having a particle size of 100 nm or less made of a multicomponent oxide glass belonging to any one of glass composition systems whose main component is V ₂ O ₅ , glass composition system whose main component is PbO, and glass composition whose main component is TeO ₂ are purchased or manufactured do.

On the other hand, in the case where the sintering is promoted along with the improvement of the fluidity of the base glass powder 10, the glass composition system in which the main component is SiO ₂ , the glass composition system in which the main component is Bi ₂ O ₃ , the glass composition system in which the main component is P ₂ O ₅ , Spherical particles having a particle size of 10 nm or less made of a multi-component oxide glass belonging to any one of the glass composition system of V ₂ O ₅ , the glass composition system of the main component of PbO and the glass composition system of the main component of TeO ₂ are purchased or manufactured and used, In the case of the nano powder 20, it is important to form the nano powder 20 so as to have a glass transition temperature lower than the glass transition temperature of the base glass powder 10.

In addition, in the case of considering improvement of the molding strength of the base glass powder 10 as well as improvement of the flowability, it is preferable to use SiO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , NiO, CoO, CeO ₂ , MgO, Spherical particles of 100 nm or less made of a single oxide of any one of CaO, WO ₃ , CuO, and Fe ₂ O ₃ are purchased or manufactured and used. In the case of the spherical nano powder 20, .

If the fluidity of the base glass powder 10 is to be enhanced and the sintering acceleration and the molding strength are to be combined, the spherical nano powder 20 may be mixed at an appropriate ratio. For this purpose, dry mixing can be carried out in a device such as a tubular mixer. In such a dry mixing process, a high impact force and a shear stress are involved between the spherical nano powder 20 and the base glass powder 10, The spherical nano powder 20 is coated on the base glass powder 10 in a state of being dispersed by the high heat and the static electricity instantaneously generated at the interface.

When the mixing step is completed, a molding material for 3D printing is obtained. As shown in FIG. 2, the molding material is in a state in which the spherical nano powder 20 is dispersed on the surface of the base glass powder 10.

Thereafter, the forming step proceeds. In the molding step, the 3D molding is formed through 3D printing using a molding material in which the base glass powder 10 and the spherical nano powder 20 are mixed through all steps. To this end, a method of forming a cross-sectional layer using the molding material is repeatedly carried out to laminate a plurality of cross-sectional layers, a liquid binder is applied each time the cross-sectional layers are formed, . Then, the laminated body formed by laminating the cross-sectional layers at regular intervals is pressed by a roller. Such a molding method is not limited to one and can be carried out in various modified ways.

It should be noted that during the molding step, as shown in FIG. 3A, the spherical nano powder 20 prevents direct contact between the base glass powder 10 and separates the spherical nano powder 20 from the base glass powder 10, When the force to flow to the base glass powder 10 is applied as shown in FIG. 3B, it serves as a bearing therebetween to maximize the fluidity. Thus, even if irregularly shaped base glass powder 10 having a rough angular shape is used as a main component of the molding material, molding by 3D printing can be performed smoothly.

Thereafter, the drying step proceeds. In the drying step, the formed body formed through the forming step is dried to prevent the molded body from being easily broken when the next step is performed.

Thereafter, the powder washing step proceeds. In the powder drying step, the powder residing in the molded body is washed. Such a powder washing operation can be repeatedly carried out before and after the drying step.

Thereafter, the binder removal step proceeds. In the binder removal step, the binder used in the molding step is removed through heat treatment. For this, the heat for removal of the binder is removed. The removal temperature of the binder is lower than the glass transition temperature of the base glass powder (10). When this binder removal step is complete, the actual preparation for sintering is complete.

Thereafter, the firing step proceeds. As shown in FIG. 3D, melting of the spherical nano powder 20 in the particle size before the maximum shrinking temperature of the base glass powder 10 is carried out at this stage, As shown in FIGS. 3E and 3F, the sintering of the base glass powder 10, which is in contact with the spherical nano powder 20, is started, and the sintering of the base glass powder 10 proceeds from an early stage . As a result, as shown in FIG. 3G, the time required until the entire firing is greatly shortened, and a sintered body of a desired article can be obtained. In order to promote the sintering, it is preferable that the spherical nano powder 20 has an average particle diameter of 10 nm or less.

Next, a description will be given below of a molded body for 3D printing and a molded body of a bio-sheath type imitation 3D molded body based on the above-described 3D printing molding method.

Fig. 5 is a longitudinal sectional view for explaining a bio-sheath type mimetic 3D formed body according to an embodiment of the present invention, Fig. 6 is a longitudinal sectional view for explaining a constitution of a living body based mimetic 3D molded body according to an embodiment of the present invention, The upper layer, and the porous layer. And Figs. 7 and 8 are enlarged configuration diagrams for explaining the detailed configuration of a living body-mimetic 3D molded article according to an embodiment of the present invention.

The bio-encapsulated mimetic 3D molded article according to the embodiment of the present invention is an imitation of an envelope structure such as a nail having a complex function such as light transmittance, shield function, and high humanity, and is imitated.

As shown in the drawing, such a molded body is configured to block dust, water, noise, and unnecessary light coming in contact with the outside, centering on the oil-rich layer 120, which is responsible for mechanical strength including toughness capable of responding to external impacts and pressures And the light transmitted through the scale layer 110 and the upper fiber layer 120 from the outside and the light transmitted in the opposite direction to control the transmittance and the noise And a porous layer 130 for absorbing and functioning as a pivotal function of weight reduction. The filler 140 may be filled in the gap between the scale layer 110 and the pores of the fibrous upper layer 120 and the porous layer 130 and the unitary structure 121.

The fiber upper layer 120 plays a role of taking mechanical strength including high toughness against impact and pressure, while ensuring light transmittance. To this end, the upper layer 120 is formed into an overlapped shape by forming fine gaps partially between the linear unit pieces 121 having a diameter of 10 μm or less so as to allow transmission of light. When the upper fibrous layer 120 is formed of the linear unit structures 121, it has high strength and elastic modulus. When crystallized based on the amorphous base glass powder 10, crystallization does not occur in a thermal environment, Strength can be maintained even with heat change.

As shown in FIG. 7, the unit fibers 121 of the upper layer 120 are piled up to form two or more types of bundles May be formed so as to be arranged to be crossed in different directions. In addition, as shown in FIG. 8, the unitary structures 121 of the upper layer 120 may be formed into a bundle of the same direction. Both of them can exhibit elastic modulus and high strength for toughness. In particular, in the case of electrons in which the unitary structures 121 of the upper layer 120 are arranged in two or more directions, the direction of mechanical strength is relatively higher than that of the latter There is an advantage that it does not happen and shows excellent effect in shock absorption. Further, in the case of the former, the unit structures 121 exhibit stronger bending strength characteristics than those of the latter in which they are arranged in one direction. However, in the latter case, there is a relative advantage that it is easier to manufacture than the former case. The fibrous upper layer 120 may be formed to have a thickness of at least 1/2 of the entire thickness of the formed body 100, so that sufficient mechanical strength including high toughness can be secured.

The scale layer 110 plays a role of shielding the air, moisture, noise, and unnecessary light, as well as foreign materials such as dust, which collide with the outside at a high speed. For this purpose, the scale layer 110 is partially overlapped in the form of scales while partially forming minute gaps between the plate-like unit tissues 111 so that light can be transmitted. 6, the unit tissues 111 of the scale layer 110 are partially overlapped in the form of scales. In this way, the plate-like unit tissues 111 in the scale layer 110 are formed in a scale- According to the laminated structure, it is possible to effectively prevent the penetration of dust, air, moisture, and even unnecessary light, which collide with the outside, and to prevent noise from being reflected. Here, it is possible to control the transmittance of light transmitted from the outside by adjusting the clearance between the unit tissues 111 of the scale layer 110. For example, as the thickness of the unit tissue 111 of the scale layer 110 is increased or the clearance between the unit tissues 111 is narrowed, the transmittance of light is lowered and the thickness of the unit tissue 111 of the scale layer 110 is decreased, The larger the clearance between the light emitting diodes 111 is, the higher the light transmittance is. Such a scale layer 110 may be relatively difficult to form by 3D printing molding using a molding material as compared to other layers. Therefore, unlike the other layers, it is also possible to form the layer by a method other than 3D printing and then bonding the layer to other layers.

The porous layer 130 is formed to have more porosity than the scale layer 110 or the fibrous layer 120 and is transmitted from the outside through the scale layer 110 and the fibrous layer 120 or from inside to outside It controls the overall transmittance against light. For this purpose, the porous layer 130 is formed into a sponge having a plurality of pores. According to the structure of the porous layer 130, the transmittance of light is relatively higher than that of the scale layer 110 and the fiber layer 120, and the light blocking rate is low. Therefore, in the inner side where the porous layer 130 is located, But it is possible to realize a function of differentiating light transmittance according to a direction in which the inside can not be easily seen from the outside where the scale layer 110 is located. Since the porous layer 130 does not have an essential function as compared with the scale layer 110 which functions as a shield or the fibrous layer 120 which functions as a mechanical property, So that the total light transmittance can be controlled.

In addition, the porous layer 130 may have a micro-bend 130b formed on the lower surface thereof in the form of a wavy shape in which a bottom portion and an obtuse portion are repeated (see an enlarged portion in FIG. 5). If the fine bending 130b is formed on the surface of the porous layer 130, the problem that the stiffness is weakened when the porous layer 130 has a higher porosity than the scale layer 110 or the fiber layer 120 can be compensated. It is possible to secure a wider area of the bonding, which is useful when the molded body 100 according to the embodiment of the present invention must be bonded to another structure. The porous layer 130 also functions to absorb noise. At this time, the micro bending 130b widens the surface area in contact with the noise, so that more amount of noise can be absorbed.

<Experimental Example>

In this experiment, the main component is SiO ₂ in composition of the glass material by 3D printing molding the crushed base material of glass powder having an average particle size in a 22㎛ _{(SiO 2 -ZnO-B 2 O} 3 -Al 2 O 3 -BaO) with a molding material The spherical nanopowder with the average particle size of 12 nm was prepared by mixing 0.5 vol.% Of the spherical nanopowder with the main component of SiO ₂ and the spherical nanopowder Were not mixed with each other. At this time, the layer thickness was 180 μm, the binder saturation was 300%, and the formed body was 10 mm × 10 mm × 5 mm. At this time, a maltodextrin aqueous solution was used as a binder solution in order to make a 3D molded body as a mixture of base glass powder and SiO ₂ spherical nano powder. In this experiment, a 10% maltodextrin aqueous solution was used and the viscosity at room temperature (21 ° C) was 4.5 cp. For reference, binder solutions that can be used for 3DP printing technology include 10% -20% maltodextrin, polyvinylalcohol, and polyvinylbutyral.

When only the base glass powder was used without mixing the spherical nano powder, the agglomeration phenomenon of the powder was severe as seen on the left side of Fig. 9 (SZB glass), and as a result, the surface of the formed body was found to be highly inhomogeneous there was. On the other hand, as can be seen from the right side of FIG. 9 (SZB glass with nano-silica), when the mixed powder containing spherical nano powder is used as the molding material, the fluidity is significantly improved in the molding process. As a result, It was also confirmed that it was homogeneous.

When sintering the molded body, the spherical nano powder was mixed with the spherical nano powder, and the sintered body was sintered using only the base glass powder. (Fig. 11), the shrinkage of the molded article was much reduced, and it was confirmed that there was a strong tendency to maintain the original shape without collapsing.

The optimum sintering temperature of the shaped body should be within the range between the maximum shrinkage temperature and the softening point of the base glass powder. As can be seen from FIG. 10, when sintering at the maximum shrinking temperature of the base glass powder, it is difficult to obtain a high sintered density because the sintered body is not fully sintered. On the other hand, when the sintering is performed at a softening temperature (Littleton softening temperature) But it is difficult to maintain the shape.

As can be seen from FIG. 12, when the base glass powder and the spherical nano powder were mixed to form a molding material so that the spherical nano powder was uniformly dispersed and coated on the surface of the base glass powder, (D) the spherical nanopowder increases the particle spacing between the base glass powder as a result of which the cohesive force (F) between the powders is reduced by the following equation.

When D ₁ = D ₂ ,

In addition, it is believed that the spherical nano powder maximizes the fluidity of the base glass powder while serving as a rolling bearing between the base glass powders.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is clear that the present invention can be suitably modified and applied in the same manner. Therefore, the above description does not limit the scope of the present invention, which is defined by the limitations of the following claims.

10: base glass powder 20: spherical nano powder
110: scale layer 120: fibrous layer
130: porous layer 140: filler

Claims (28)

As a forming material for 3D printing for forming a three-dimensional composite,
A base glass powder having an irregular shape in an amorphous glass powder state and an average particle diameter in a range of 1 to 200 mu m;
Wherein the spherical nanopowder has an average particle diameter of 100 nm or less and is mixed with the base glass powder so as to be positioned on the surface of the base glass powder to improve the fluidity of the base glass powder having an irregular shape when formed by 3D printing. The method according to claim 1,
The raw material of the base glass powder is a glass composition system in which the main component is SiO ₂ , a glass composition system in which the main component is Bi ₂ O ₃ , a glass composition system in which the main component is P ₂ O ₅ , a glass composition system in which the main component is V ₂ O ₅ , And a glass composition system whose main component is TeO ₂ . The method according to claim 1,
Wherein the base glass powder is obtained by first crushing the glass by ball milling to form a coarse powder and then secondary crushing by jet milling or ball milling to form a fine powder. The method according to claim 1,
The raw material of the spherical nano powder is a glass composition system in which the main component is SiO ₂ , a glass composition system in which the main component is Bi ₂ O ₃ , a glass composition system in which the main component is P ₂ O ₅ , a glass composition system in which the main component is V ₂ O ₅ , A glass composition system whose main component is TeO ₂ or a glass composition system mainly composed of SiO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , NiO, CoO, CeO ₂ , MgO, CaO, WO ₃ , CuO, And Fe ₂ O ₃ as a main component. The method according to claim 1,
Wherein the spherical nano powder has a glass transition temperature lower than a glass transition temperature of the base glass powder, so that the sintering of the base glass powder is promoted. The method according to claim 1,
Wherein the spherical nano powder is made of any one of a single oxide which does not react with the base glass powder at the time of sintering the base glass powder so as to increase the molding strength together with the fluidity of the base glass powder. Molding material for printing. The method according to claim 1,
Wherein the spherical nano powder is coated on the surface of the base glass powder by heat and static electricity while being dispersed on the surface of the base glass powder. The method according to claim 1,
Wherein the spherical nano powder is mixed at a mixing ratio in the range of 0.01 vol% to 1 vol% relative to the whole. A 3D printing forming method for forming a three-dimensional composite,
A crushing step of crushing the amorphous glass to produce a base glass powder having an irregular shape in an unmelted powder state and having an average particle diameter in the range of 1 to 200 mu m;
Mixing a spherical nano powder having an average particle size of 100 nm or less as a flowability improving material for improving fluidity of the base material glass powder;
A molding step of molding a 3D formed body using mixed powder in which the base glass powder and the spherical nano powder are mixed;
And a firing step of firing the molded body formed in the forming step. 10. The method of claim 9,
The raw material of the base glass powder is a glass composition system in which the main component is SiO ₂ , a glass composition system in which the main component is Bi ₂ O ₃ , a glass composition system in which the main component is P ₂ O ₅ , a glass composition system in which the main component is V ₂ O ₅ , And a glass composition system whose main component is TeO ₂ . 10. The method of claim 9,
In the crushing step, glass is first crushed by ball milling to form a coarse powder, and secondary crushing is performed by jet milling or ball milling to sequentially form fine powder to form the base glass powder The molding material for 3D printing. 10. The method of claim 9,
Wherein the amorphous glass before crushing is a cullet in which a molten glass material is poured into a ribbon roller to be thinned. 10. The method of claim 9,
Wherein the spherical nano powder is dispersed on the surface of the base glass powder by heat and static electricity in the mixing step. 14. The method of claim 13,
Wherein the base glass powder and the spherical glass powder are mixed by dry mixing. 10. The method of claim 9,
Wherein a drying step of drying the molded body and a powder washing step of removing the powder remaining on the molded body are performed between the molding step and the firing step. 10. The method of claim 9,
Wherein a binder removing step of burning and removing the binder used in the forming step is performed between the molding step and the firing step and the removal temperature of the binder is lower than the glass transition temperature of the base material glass powder. Printing molding method. 10. The method of claim 9,
Wherein the spherical nano powder has a glass transition temperature lower than a glass transition temperature of the base glass powder so as to promote sintering of the base glass powder in the sintering step. 10. The method of claim 9,
Said spherical nano-powder is _{SiO 2, Y 2 O 3,} Al 2 O 3, TiO 2, ZrO, NiO, CoO, CeO 2, MgO, CaO, WO 3, CuO, Fe 2 O 3 Wherein the glass beads are made of a single oxide having an average particle size of 100 nm or less so as to increase the molding strength as well as the fluidity of the base glass powder. 10. The method of claim 9,
Wherein the sintering of the molded body in the sintering step proceeds at a temperature within a range between a maximum shrinkage temperature of the base glass powder and a softening temperature. 20. A method of forming a molded body of an in vitro skin mimetic 3D object using the 3D printing molding method according to any one of claims 9 to 19,
Wherein a plurality of voids are formed in the molding step so as to have translucency and light weight. 21. The method of claim 20,
Characterized in that at least one layer is formed into a porous layer formed with a plurality of voids and at least one layer including a layer adjacent to the porous layer is formed into a fibrous layer having superposed linear unit structures Wherein said method comprises the steps of: 22. The method of claim 21,
Wherein the linear unit tissues are arranged at least partially in an intersecting manner. 23. The method of claim 22,
Wherein the linear unitary structures in the upper layer of the fibrous layer are formed into a superposed shape while partially forming fine gaps with each other. 22. The method of claim 21,
Wherein the layer adjacent to at least one of the fibrous layer and the porous layer is formed into a layer of scales in which plate-like unit tissues are partially folded in a scaly shape. 9. A molded body of a bio-sheath type mimetic 3D formed body formed from a molding material for 3D printing according to any one of claims 1 to 8, and having a plurality of voids formed therein, and having transparency and light weight. 26. The method of claim 25,
The molded body has a multi-layer structure, at least one of which is a porous layer formed with a plurality of voids, and at least one of the remaining layers except for the porous layer is a fibrous upper layer formed by overlapping linear unit structures. 3D-shaped body. A 3D molded article of a bio-sheath type mimetic 3D molded article, which is formed to have a plurality of voids by a 3D printing molding method according to any one of claims 9 to 19 so as to have translucency and light weight. 28. The method of claim 27,
The molded body has a multi-layer structure, at least one of which is a porous layer formed with a plurality of voids, and at least one of the remaining layers except for the porous layer is a fibrous upper layer formed by overlapping linear unit structures. 3D-shaped body.

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