KR20210125689A - A bottom-up 3D printing device with heating vat to control high viscosity materials and control method thereof - Google Patents

Abstract

The present invention relates to a bottom-up 3D printing device with a heating vat to control high viscosity materials, which minimizes a making failure of a material platform. According to the present invention, the bottom-up 3D printing device comprises: a header for curing a material linearly moving in the Z-axis direction by a linear actuator; a heating vat disposed at the lower end of the header for curing a material to accommodate a high-viscosity material including zirconia (ZrO_2); and a light source unit emitting ultraviolet light for curing the material in the upper and lower parts of the heating vat. The heating vat includes: a body part including four side parts, wherein a heating member for heating the material to a predetermined temperature or higher to lower the viscosity of the high-viscosity material is inserted into each side part; and a film fixing part disposed on the lower part of the body part to fix a release film which is a transparent material passing the ultraviolet light.

Description

A bottom-up 3D printing device with heating vat to control high viscosity materials and control method thereof

The present invention relates to a bottom-up type 3D printing apparatus having a heating bat to control a high-viscosity material and a control method thereof, and more particularly, to heat a resin tank or the production platform itself so that the high-viscosity material can maintain a certain temperature or more. By doing so, it relates to a bottom-up 3D printing apparatus having a heating bat to control a high-viscosity material having improved fluidity of the material, and a method for controlling the same.

The conventional 3D printer can be divided into a top-down method and a bottom-up method.

The top-down 3D printer is cured by irradiating a light source from the upper part of the resin filled in the vat, and the Z-axis driving part moves downward while the cured material is fixed on the upper surface of the production platform. While the next material layers are stacked in the upper direction, they are manufactured.

The bottom-up 3D printer irradiates a light source from the bottom of the resin filled in the water tank to harden the material, and while the cured material is fixed to the bottom of the production platform, the Z-axis drive moves upward while the next material layer is lowered. It is manufactured by stacking in the direction.

A double top-down 3D printer uses a recoater to fabricate every layer of a structure, whereas a bottom-up 3D printer can omit the recoater when manufacturing a structure.

However, among the bottom-up 3D printers, the 3D printer using zirconia (Zirconia, ZrO ₂ ) has a remarkably high failure rate of product manufacturing due to the high viscosity of zirconia, resulting in a high defect rate.

In addition, a light source for curing the resin is placed at the lower part, but due to the material properties of zirconia, the curing depth is not deep, so the layer could not be properly seated on the production platform.

Accordingly, there is a need for technology development to solve the disadvantages of the bottom-up type 3D printer using the above-described high-viscosity material.

The present invention has been devised to respond to the above-described technical problem, and an object of the present invention is to be able to substantially supplement various problems caused by limitations and disadvantages in the prior art, and a high-viscosity material can maintain a certain temperature or more. An object of the present invention is to provide a bottom-up 3D printing apparatus equipped with a heating bat to control a high-viscosity material with improved fluidity of the material by heating the resin tank or the production platform itself.

In order to solve the above problems, a bottom-up 3D printing device having a heating bat to control a high-viscosity material according to an embodiment of the present invention is a header for material curing that linearly moves in the Z-axis direction by a linear actuator; And it is disposed at the bottom of the header for curing the material zirconia (ZrO ₂ ) A heating bat for accommodating a high-viscosity material including; And in the 3D printing apparatus comprising a light source for irradiating ultraviolet light for curing the material in the upper and lower portions of the heating bat, the heating bat includes four side portions, and each side portion has the viscosity of the high-viscosity material. a body portion into which a heatable member for heating the material to a certain temperature or more to lower it is inserted; and a film fixing part disposed under the body part to fix a release film that is a transparent member through which the ultraviolet light passes.

In addition, the heatable member of the present invention is formed with a length corresponding to the height of the side portion and may have a long cylindrical shape.

In addition, the heatable member of the present invention is arranged in the form of a band wrapped around the heating bat along the edge of the heating bat, the heating wire may be spaced apart from each other and arranged in parallel.

In addition, a hole is formed in the center of the lower end surface of the body portion of the present invention, and the release film may transmit light through the hole.

In addition, the light source unit is disposed under the manufacturing platform a first light source unit for irradiating light in an upward direction; and a second light source unit disposed on top of the manufacturing platform to irradiate light in a downward direction, wherein the first light source unit and the second light source unit can simultaneously irradiate light to one layer stacked on the manufacturing platform. have.

In addition, the first light source unit may be a DLP projector, and the second light source unit may be an LED.

In addition, the heating bat may be disposed between the first light source unit and the second light source unit.

On the other hand, the control method of the bottom-up type 3D printing apparatus having a heating bat to control the high-viscosity material according to another embodiment of the present invention comprises the steps of: receiving information about a structure to be manufactured from a computing device through a network communication network; controlling the movement of a header for material curing fixed to the linear actuator based on the information on the structure; And when the layers are laminated layer by layer based on the movement of the header for material curing, it is disposed at the lower end of the header for material curing _{and accommodating a high-viscosity material containing zirconia (ZrO 2} ) Heating a heating vat (Heating Vat); Including, a heatable member for heating the high-viscosity material to a certain temperature or higher in order to lower the viscosity of the high-viscosity material may be inserted into the side portion of the heating bat.

The solution of the problem according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.

The present invention has the effect of minimizing the manufacturing failure rate for the material platform by increasing the depth of curing using two light sources that irradiate light of the same wavelength band to the high-viscosity material.

In addition, the present invention has the effect of improving the fluidity of the material by heating the resin tank or the production platform itself so that the high-viscosity resin can be maintained at a certain temperature or more.

In addition, the present invention has an effect of minimizing the blur by flattening the surface of the high-viscosity resin and at the same time recoating it by using a blade in the form of a triple blade having a material inlet hole.

In addition, the present invention can improve the reliability of the product by minimizing the manufacturing failure rate.

The 3D printing apparatus 1000 according to another embodiment of the present invention has the effect of minimizing a measurement error by fixing the focal length of the DLP without using a laser sensor.

In addition, the present invention has the effect of increasing the completeness of the product by reducing the disturbance factor due to the high viscosity when the device using the high-viscosity resin is manufactured by the next layer by maintaining the DLP focal length constant through the movement of the blade.

In addition, the present invention has the effect of reducing the time because the DLP focal length is kept constant, and there is no need to descend the manufacturing platform even if the material height is high.

The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a cross-sectional view of a 3D printing apparatus according to an embodiment of the present invention.
2 is an enlarged view for explaining a header for material curing of the 3D printing apparatus according to an embodiment of the present invention.
3 is an exemplary view for explaining the problems of the bottom-up type 3D printing apparatus according to the comparative example of the present invention.
4 is an exemplary view for explaining a resin curing process of the 3D printing apparatus according to an embodiment of the present invention.
5 is an exploded perspective view for explaining a heating bat according to an embodiment of the present invention.
6 is a flowchart illustrating a control process of a bottom-up 3D printing apparatus according to an embodiment of the present invention.
7 is a flowchart for explaining the movement of the edge blade according to the movement of the blade according to an embodiment of the present invention.
8 is an exemplary view showing the movement of the blade according to the manufacture of the product according to the embodiment of the present invention.
9A to 9B are exemplary views for explaining a material inflow and recoating process based on the movement of an edge blade according to an embodiment of the present invention.
10 is a cross-sectional view showing a top-down 3D printing apparatus according to another embodiment of the present invention.
11 is an exemplary view for explaining an operation process of a top-down type 3D printing apparatus according to a comparative example of the present invention.
12 is an exemplary view for explaining a problem of a top-down method 3D printing apparatus according to a comparative example of the present invention.
13 is an enlarged perspective view for explaining a DLP focus surface according to an embodiment of the present invention.
14 is a perspective view showing a resin tank according to another embodiment of the present invention.
15 is an exemplary view for explaining the blade movement and material supply process according to the DLP focal length according to another embodiment of the present invention

Advantages of the invention, and methods of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in a singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and technically various interlocking and driving are possible, as will be fully understood by those skilled in the art, and each embodiment may be independently implemented with respect to each other, It may be possible to implement together in a related relationship.

Hereinafter, a bottom-up type 3D printing apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3 .

1 is a cross-sectional view of a 3D printing apparatus according to an embodiment of the present invention. 2 is an enlarged view for explaining a header for material curing of the 3D printing apparatus according to an embodiment of the present invention. 3 is an exemplary view for explaining the problems of the bottom-up type 3D printing apparatus according to the comparative example of the present invention.

The 3D printing apparatus 100 according to an embodiment of the present invention forms a layer-by-layer structure (or a 3D output, based on a dental product in the present invention) while transporting the manufacturing platform to which the material is attached in the upward direction and stacking it. This is a bottom-up printer. In the present invention, the material is preferably interpreted as referring to a state in which a photocurable resin described later is cured by a laser beam (or ultraviolet or visible light) and an LED. In the present invention, the 3D printing apparatus 100 is based on a digital light processing (DLP) method. However, depending on the embodiment, a photopolymerization method (Vat Photopolymerization), Formlabs' Form series, SLA (Stereo Lithography Apparatus) method, etc. may be used.

1, the 3D printing apparatus 100 is a servo motor (Survo Moter, 110), a linear actuator (Linear Actuator, 111), a block 112, a header support 120, a header for material curing (130), It includes a base plate 140 , a resin tank 150 fixed to the base plate, an optical lens unit 160 , a blade 170 , and a support frame FR.

The servo motor 110 is configured to control the movement of the linear actuator 111 . Specifically, the servo motor 110 receives the position value from the computing device through the network communication network, and linearly moves the material curing header 130 fixed to the actuator 120 in the vertical direction. The servo motor 110 is disposed on the upper end of the linear actuator as shown in FIG. 1 . Meanwhile, the motor for controlling the movement of the linear actuator 111 is not limited thereto, and a step motor (or a stepping motor) may be used.

The block 112 is configured to move in the vertical direction according to the movement of the screw thread of the ball screw formed in the linear actuator 111 , and is formed to be fixed to the front surface of the linear actuator 111 . The header support 120 is fixed to one surface of the block 112 by at least four screws. The header support 120 is configured to support the header 130 for material curing located on the opposite side to the surface fixed to the block 112 .

The material curing header 130 is disposed on the resin tank 150 to be described later to cure the high-viscosity photocurable resin accommodated in the resin tank 150, and includes an LED. Here, the LED may be referred to as a first light source unit. Specifically, the header 130 for curing the material includes a cooling fan 131 , a heat sink 132 , an LED 133 , a light path 134 , and a fabrication platform 135 .

The cooling fan 131 is disposed on the upper end of the header 130 for curing the material, and serves to cool the heat generated by the LED 133 disposed in the central portion by the heat sink 132 by introducing external air. Accordingly, the life of the LED 133 may be extended by cooling and heat dissipation treatment.

At the lower end of the header 130 for curing the material, a manufacturing platform 135 is located, which is an area in which structures to be manufactured are stacked layer by layer. In other words, on the lower surface of the fabrication platform 135 , a solid material in which a liquid photocurable resin is cured by photopolymerization (hereinafter also referred to as degradation reaction) by a laser beam irradiated from the bottom is laminated layer by layer. A light path 134 is disposed between the fabrication platform 135 and the LEDs. The light path 134 is a path through which the UV LED irradiated from the LED 133 is irradiated.

Further details related to material hardening using the material hardening header 130 will be described later with reference to FIG. 4 .

The base plate 140 has a configuration in which the above-described linear actuator 111 and various components are formed. Specifically, referring to FIG. 2 , a rack gear RG formed on the ground in a direction perpendicular to the longitudinal direction of the linear actuator 111 , is fixed to the rack gear RG, and in the longitudinal direction of the rack gear RG. A resin tank 150 is formed that accommodates the reciprocating guide block GB and the blade 170 fixed to the guide block GB and contains a high-viscosity photocurable resin. In addition, the base plate 140 further includes various components for fixing the above-described components, but has been omitted for convenience of description.

The resin tank 150 accommodates a high-viscosity photocurable resin (hereinafter, also referred to as “photopolymerizable material” or “resin”), and may be referred to as a vat. In addition, the resin tank 150 according to the embodiment of the present invention is characterized in that it performs a heating function to lower the viscosity of the high-viscosity photocurable resin to a certain level or less. Accordingly, the resin tank 150 may be referred to as a heating vat. A more detailed description related thereto will be described in detail with reference to FIG. 5 and the like.

The lower surface of the resin tank 150 is composed of a light-transmitting member (hereinafter, also referred to as a 'transparent plate'), and the side is composed of a wall formed along the edge of the lower surface. At this time, the wall consists of 4 sides, and one side of the wall is formed to a lower height than the other side of the wall so that the height of the photocurable resin accommodated in the resin tank 150 can be observed, or is composed of a transparent member such as the bottom side. could be In addition, the resin tank 150 is characterized in that it is supported by the resin tank support 180 fixed to the base plate (140).

In addition, in the present invention, the photocurable resin serves to cure the next material layer according to the movement of the manufacturing platform 1310 by the material adhered to the manufacturing platform 135, and in the present invention, the photocurable resin is zirconia (ZrO). ₂₎ as characterized by having a high viscosity containing a. the viscosity of the resin is zirconia (ZrO ₂₎ but not become different depending on the content typically zirconia (ZrO ₂₎ is compared with the non-containing resin to a very high viscosity ally of It is desirable to understand

However, in general, dental zirconia (ZrO ₂ ) particles are prepared by mixing Tetragonal (square, hexahedral) type particles and Cubic (cubic, cube) type particles. At this time, when light passes through zirconia having many Tetragonal (square, hexahedral) particles, a lot of light scattering occurs (hereinafter, also referred to as “because light is diffused in the horizontal direction”), and thus the transparency is lowered. On the other hand, when light passes through cubic (cubic, cube) particles, the light passes straight through without scattering (hereinafter, also referred to as “light diffuses in the vertical direction”), making it appear more transparent. It is characterized by having aesthetics. Accordingly, a material containing more cubic-type particles than tetragonal-type particles is suitable as a dental material because it can implement a shape similar to natural teeth due to high transparency.

However, since general zirconia (ZrO ₂ ) has a tetragonal particle content of about 80%, the depth of hardening by DLP is low, and light is diffused in the horizontal direction because light is scattered. Accordingly, the zirconia product that is not cured properly has a disadvantage in that it fails to be seated on the manufacturing platform with high probability when the first layer is formed because the adhesive strength is not excellent.

In addition, since general zirconia (ZrO ₂ ) has low fluidity of the material (or resin) due to its high viscosity, as shown in FIG. There is a problem in that (or grooves) remain formed. Accordingly, when using general zirconia (ZrO ₂ ), the material must be introduced into the empty space formed for the production of the next layer (or layer), but there is a problem in that the material is not easily introduced due to high viscosity. In other words, as shown in FIG. 3 , the production platform 931 moves in the Z-axis direction according to the structure production. At this time, the resin accommodated in the resin tank 950 has high viscosity due to _{zirconia (ZrO 2 ).} It can be seen that an empty space corresponding to the shape of the fabricated structure (eg, tooth shape) is formed in the resin.

The optical lens unit 160 is disposed on the lower portion of the resin tank 150 , that is, the base plate ( ) to cure the photocurable resin accommodated in the resin tank. The optical lens unit 160 may be referred to as a second light source unit. The optical lens unit 160 is disposed at the lower end of the base plate and is protected by a frame disposed to support the four corner sides of the base plate.

The blade 170 is composed of a triple blade, that is, a central blade and an edge blade disposed on both sides of the central blade. Here, as the height of the two edge blades is adjusted, the central blade and the two edge blades disposed on both sides may have different heights. The blade 170 flattens the film disposed on the lower surface of the resin tank 150 and the surface of the photocurable resin accommodated in the resin tank 150 (hereinafter, also referred to as “recoating”), and the surface of the resin It fills the empty space formed in the The detailed configuration and operation process of the blade 170 will be described later with reference to FIGS. 8 to 10B .

Hereinafter, an operation of curing the resin by the first light source unit 133 and the second light source unit 160 according to an embodiment of the present invention will be described with reference to FIG. 4 .

4 is an exemplary view for explaining a resin curing process of the 3D printing apparatus according to an embodiment of the present invention.

Referring to FIG. 4, the 3D printing apparatus 100 superimposes and hardens the upper and lower portions of the resin so that ^{the first layer (1 st layer) of the structure to be manufactured can be stably seated on the lower end of the production platform 135.} do.

Specifically, the 3D printing apparatus 100 is disposed on the upper portion of the resin tank 150 and laminated layer by layer on the lower surface of the production platform 135 that moves linearly in the Z-axis direction to form a structure (hereinafter, “production structure”). Also called), characterized in that it is produced. At this time, the upper end of the layer is cured using the first light source unit 133 so that the layers stacked layer by layer can be stably seated layer by layer, and the lower end of the layer is cured using the second light source unit 160 at the same time. do.

That is, the 3D printing apparatus 100 according to the embodiment of the present invention may form a depth (or degree) of curing deeper than that of a conventional 3D printing apparatus by overlapping and curing one layer. Accordingly, due to the high-viscosity material adhered to the manufacturing platform 135 by the two light sources, there is an effect of allowing the material to be easily separated from the lower projection window.

Here, as shown in FIG. 4 , the first light source unit 133 is disposed on the upper end of the fabrication platform 135 and includes an LED 133 for irradiating ultraviolet (UV, UltraViolet). In addition, the second light source unit 160 is a DLP (Digital Light Projector) projector disposed at the bottom of the manufacturing platform 135 and irradiating the same wavelength band as the ultraviolet (UV).

Hereinafter, a heatable resin tank 150 (hereinafter, also referred to as a “heating bat”) according to an embodiment of the present invention will be described with reference to FIG. 5 .

5 is an exploded perspective view for explaining a heating bat according to an embodiment of the present invention.

In general, the resin used in the 3D printing apparatus uses a polymer-based material, and has a characteristic that the viscosity decreases as the temperature increases. Likewise, even in a material containing zirconia (ZrO ₂ ), the higher the temperature, the lower the viscosity.

In the present invention, a heatable resin tank 150 is used to lower the viscosity of high-viscosity zirconia (ZrO _{2 ) by using the above-described characteristics.} Hereinafter, for convenience of description, the heatable resin tank 150 will be referred to as a 'heating bat'.

Referring to FIG. 5 , the heating bat 150 includes a body part 151 , a film fixing part 152 , and a lower surface part 153 of the resin tank support.

The body portion 151 has four side portions, and a heater (hereinafter, also referred to as a “heatable member”) formed in the height direction (or Z-axis direction) is inserted in the center of each side portion. The heater serves to heat the heating bat 150 to a constant temperature in order to drop the viscosity of the resin accommodated in the heating bat to a predetermined level or less. As shown in FIG. 5 , the heater is formed in a long cylindrical shape, and an electrode for transferring heat from the heater may be formed at the lower end. However, the shape of the heater is not limited thereto.

For example, the heater may be formed in the form of a hot wire, and the position at which the heater is formed can be easily changed in design according to the embodiment. For example, when the heater is formed in the form of a heating wire, a plurality of parallel heating wires are wrapped in a horizontal direction along the edge of the heating bat 150 so that the heating bat 150 can have a uniformly constant temperature. It may be formed, or a plurality of parallel heating wires may be formed in a vertical direction along the edge of the heating bat 150 .

Therefore, the 3D printing apparatus 100 according to the embodiment of the present invention has the effect of increasing the fluidity of the resin by heating the heating bat 150 to a constant temperature by dropping the viscosity of the resin accommodated therein to a certain level or less.

According to another embodiment, in order to lower the viscosity of the resin, the production platform 135 itself that directly contacts the resin may be heated while reciprocating in the Z-axis direction, rather than by heating the resin tank 150 . In this case, the manufacturing platform 135 may be heated by inserting a heater or inserting a heating wire, as described above.

According to another embodiment, it may be implemented in a combination of the form of heating the resin tank 150 and the form of heating the manufacturing platform.

Hereinafter, an overall operation process of the 3D printing apparatus operating in a bottom-up method according to an embodiment of the present invention will be described with reference to FIG. 6 .

6 is a flowchart for explaining a control process of a bottom-up 3D printing apparatus according to an embodiment of the present invention.

Referring to FIG. 6 , the 3D printing apparatus 100 controls the movement of the header 130 for curing the material fixed to the linear actuator 111 ( S100 ). Specifically, the 3D printing apparatus 100 receives information about a structure to be manufactured from a computing device through a network communication network, and then manufactures the structure based on the received information. Accordingly, the material hardening header 130 uses the high-viscosity resin accommodated in the resin tank 150 while linearly moving in the Z-axis direction. layer by layer

At this time, _{in order to lower the viscosity of the high-viscosity resin containing zirconia (ZrO 2} ), a heating vat or a manufacturing platform is heated (S200). Since the resin of the present invention _{has high viscosity due to zirconia (ZrO 2} ), it is important to planarize the surface of the resin every time a layer is produced and at the same time fill the empty space created on the surface of the resin so that there is no problem when stacking the next layer. .

Therefore, the 3D printing apparatus 100 according to the embodiment of the present invention lowers the viscosity of the resin by forming the resin tank 150 in a heatable structure, or by heating the production platform 135 itself, It is characterized in that by increasing the temperature of the resin in direct contact with the production platform 135 by temperature, the viscosity is lowered.

Then, when the layers are stacked, the light from the first light source unit 133 and the second light source unit 160 is controlled ( S300 ). Specifically, each time the layers are stacked, the first light source unit 133 located at the upper side and the second light source unit 160 located at the lower side are irradiated with UV in the same wavelength band to cure the upper end and lower end of one layer at the same time. do it with Therefore, the 3D printing apparatus 100 according to the embodiment of the present invention has the effect of overcoming the curing limit of the conventional DLP projector by increasing the depth of curing by approximately two times or more by additionally arranging a light source at the upper end. . Accordingly, the 3D printing apparatus 100 according to an embodiment of the present invention increases the settling rate of the manufacturing platform by overcoming the limitations of the 3D printing apparatus using the existing high-viscosity material, and by minimizing the manufacturing failure rate, it is possible to increase the completeness of the product. there is an effect

Then, the movement of the blade 170 is controlled to flatten the surface of the high-viscosity resin (S400). Specifically, the 3D printing apparatus 100 of the present invention controls the movement of the blade 170 composed of a triple blade to fill the empty space of the resin, coat the film located at the bottom of the resin tank, and remove the surface of the resin. It is characterized by coating. A more detailed description related to the movement of the blade 170 will be described later with reference to FIGS. 7 to 9B .

Hereinafter, a blade 170 according to an embodiment of the present invention will be described with reference to FIGS. 7 to 9B .

7 is a flowchart for explaining the movement of the edge blade according to the movement of the blade according to an embodiment of the present invention. 8 is an exemplary view showing the movement of the blade according to the manufacture of the product according to the embodiment of the present invention. 9A to 9B are exemplary views for explaining a material inflow and recoating process based on the movement of an edge blade according to an embodiment of the present invention. In FIG. 9B, the directions of the X-axis and Y-axis are shown as different from those of FIG. 9A, but in FIGS. 9A and 9B, it is preferable to understand that the movement direction of the blade is parallel to the X-axis, but only the movement direction is different, and the components are substantially the same Therefore, a duplicate description will be omitted.

The resin having a high temperature above a certain temperature by the heating bat 150 or the heatingable fabrication platform 135 may change the properties of the material, and the viscosity may no longer be lowered. Accordingly, when the resin is not completely cured by UV ultraviolet rays, the zirconia powder may be adhered to the release film located at the bottom of the resin tank 150 to cause a blur.

Therefore, the 3D printing apparatus 100 of the present invention produces the blade 170 as shown in FIGS. 9A to 9B and coats the release film and the resin, thereby solving the above-mentioned conventional problems. there is

Referring to FIG. 7 , the guide block GB to which the blade 170 is fixed is linearly moved in one direction so that the layers are stacked layer by layer ( S410 ). Then, based on the blade movement direction, the first edge blade (in this case, the first edge blade is not limited to the first edge blade 172 of the present specification) located on the side where the resin is first introduced is raised by a certain height. (S420). The empty space formed during the production of the previous layer is filled with the resin introduced into the gap between the raised edge blade and the center blade (S430). The resin remaining after filling the empty space is coated on the upper surface of the release film by using the second edge blade located on the opposite side to the first edge blade (S440). The blade 170 is linearly moved in a direction opposite to the one direction to return it to its original position (S450). A more detailed description of each step will be described with reference to FIGS. 8 to 9B .

Referring to FIG. 8 , the blade 170 is fixed to one area of the guide block GB fixed to the rack gear RG and reciprocates in the left and right directions along the upper surface of the fabrication area formed in the resin tank 150 . Layer by layer. When stacking one layer, the blade moves in one direction and then returns to its initial state. In other words, the blade starts from the left, moves to the right, and then returns to the left as one round.

Referring to FIG. 9A , the blade 170 is a central blade 171 having an overall 'L' shape, a first edge blade 172 and a second formed in a symmetrical shape on both sides of the central blade 171 . It is composed of an edge blade 173 . The edge portion of the central blade 171 is a horn-shaped blade that becomes sharper toward the center portion, the edge portion of the first edge blade 172 is a right-angled triangle-shaped blade with a sharp left edge, and the edge portion of the second edge blade 173 is It is characterized by a right-angled triangle-shaped blade with a sharp right edge. In addition, the inclined surfaces of the edge blades (172, 173) are characterized in that the steeper than the inclination of the central blade (171).

Specifically, the central blade 171 is divided into a first region 171-1 formed in a direction parallel to the Z-axis and a second region 171-2 formed in a direction perpendicular to the first region 171-1. can be A hole 177 is formed in the first region 171-1 of the central blade so that the blade 170 can be fixed to the guide block GB. In the second region 171-2 of the central blade, there are 3 long oval-shaped holes (hereinafter, also referred to as “height adjustment holes 175”) so that the heights of the two edge blades disposed on both sides can be variably fixed. dog is formed At this time, a circular hole 176 is formed in the first edge blade 172 and the second edge blade 173 to correspond to the position of the oval-shaped hole 175, and two holes ( 175, 176) is fitted with one screw. The height of the first edge blade 172 and the second edge blade 173 is adjusted by the height of the oval-shaped hole 175 formed in the central blade 171 . That is, the first edge blade 172 and the second edge blade 173 are characterized by reciprocating up and down by the height of the oval-shaped hole 175 .

In addition, in the second region 171-2 of the central blade, the second region 171-2 is provided so that a certain amount of material (or resin) can be applied to the release film while solving the aggregation phenomenon of the material according to the blade movement direction. An oval-shaped hole (hereinafter, also referred to as a “material inlet hole 174”) formed long in parallel with the longitudinal direction of is formed.

Accordingly, referring to FIG. 9A , when the blade is parallel to the X-axis and moves to the right, there is a resin (hereinafter, “material”) in the movement direction material inlet hole 174 of the blade 170 in the direction opposite to the blade movement direction. also called) is introduced. When the blade 170 moves in this way, the edge blade located on the side where the material is first introduced is characterized in that the height is adjusted while moving upward through the height adjustment hole 175 formed in the central blade 171 . In addition, the height of the edge blade located opposite to the side where the material is first introduced does not change, but the blade of the opposite edge blade (hereinafter referred to as “point”) and the blade of the center blade have a basically constant height difference. do. However, the difference in height between the point of the opposite edge blade and the point of the central blade is characterized in that it is significantly smaller than the height difference between the point of the edge blade located on the side where the material is first introduced and the central blade.

In more detail, referring to FIG. 9A , the second edge blade 173 located on the side where the material is first introduced according to the blade movement direction moves upward, and the gap between the release film and the second edge blade 173 . The resin is introduced to enter the material inlet hole (174). The resin introduced through the material inlet hole 174 moves downward along the inclined surface of the first edge blade 172 and at the same time fills the empty space formed on the surface of the resin according to the previous layer production, and fills the empty space The resin is characterized in that it is coated on the release film at a constant height using the first edge blade 171 .

FIG. 9B differs from FIG. 9A only in that the blade movement direction is opposite. In other words, according to the blade movement direction, the first edge blade 172 located on the side where the material is introduced first moves upward, and the resin flows into the gap between the release film and the first edge blade 172 to introduce the material. It enters the hall 174. The resin introduced through the material inlet hole 174 moves downward along the inclined surface of the second edge blade 172 and at the same time fills the empty space formed on the surface of the resin according to the previous layer production, and fills the empty space The resin is characterized in that it is coated on the release film at a constant height using the second edge blade 171 .

As such, the bottom-up 3D printing apparatus 100 according to an embodiment of the present invention uses two light sources that irradiate light in the same wavelength band to a high-viscosity material to deepen the curing depth, thereby minimizing the manufacturing failure rate for the material platform. There is an effect that can be done.

In addition, the bottom-up 3D printing apparatus 100 according to the embodiment of the present invention has the effect of improving the fluidity of the material by heating the resin tank or the production platform itself so that the high-viscosity resin can be maintained at a certain temperature or higher. .

In addition, the bottom-up 3D printing apparatus 100 according to an embodiment of the present invention uses a triple-edged blade having a material inlet hole to planarize the surface of the high-viscosity resin and simultaneously recoat and blur it. It has the effect of minimizing the (blur) phenomenon.

In addition, the bottom-up 3D printing apparatus 100 according to the embodiment of the present invention can improve the reliability of the product by minimizing the manufacturing failure rate.

10 is a cross-sectional view showing a top-down 3D printing apparatus according to another embodiment of the present invention. 11 is an exemplary view for explaining an operation process of a top-down type 3D printing apparatus according to a comparative example of the present invention. 12 is an exemplary view for explaining a problem of a top-down method 3D printing apparatus according to a comparative example of the present invention. The 3D printing apparatus 1000 illustrated in FIG. 10 is different from the 3D printing apparatus 100 illustrated in FIG. 1 in a layer stacking method, but overlapping descriptions will be omitted because some configurations are overlapped.

10, the top-down 3D printing apparatus 1000 according to another embodiment of the present invention is a servo motor 1201, a linear actuator 1202, a block 1203, a resin tank accommodating a high viscosity resin ( 1210), a production platform 1220 in which the structure is stacked layer by layer on the upper surface, a blade 1230 for flattening and coating the surface of the resin when each layer is stacked, and a liquid photocurable resin repeatedly supplied to the resin tank 1210 and a light source unit 1270 irradiating light for material curing at the upper end of the pump 1260 and the manufacturing platform 1220 to recover.

The fabrication platform 1220 is a solid material in which a liquid photocurable resin is cured by photopolymerization on the upper surface of the fabrication platform 1220 by a UV laser (hereinafter, also referred to as a “laser beam”) irradiated from the light source unit 1270 . are stacked layer by layer. At this time, in the case of the Top-Down method, since the structure is manufactured and the height of the consumed material must be kept constant, in general, the 3D printing apparatus of the Top-Down method is shown in FIG. As described above, it is characterized in that the height of the layer (or material) to be stacked is measured using the laser sensor 920 when each layer is stacked. Here, in order to maintain the focal length of the light source unit 910 (eg, DLP or LCD) according to the measured height of the material, the recoater 940 fills the material, or moves the light source unit 910 in the Z-axis direction, etc. It is based on performing a unique operation for each 3D printing equipment.

However, in the case of a device using a material containing zirconia among top-down 3D printing devices, it is difficult to accurately measure the height of the material by the above-described method (that is, a method of measuring with a laser sensor) due to the high viscosity of zirconia. There were limits.

In addition, since it is generally difficult to install the laser sensor 920 in the area where the structure is manufactured on the manufacturing platform 930, as shown in FIG. A laser sensor 920 is installed on the edge. However, in the case of a resin containing zirconia, a measurement error may occur due to the high viscosity of the material, and the height of the material may vary. In addition, there is a problem in that the movement of the manufacturing platform 930 and the resin tank 950 also has no fluidity due to the high viscosity of the material, so that it is difficult to form a new layer for manufacturing the next layer. That is, since the viscosity of the material is high, the material is not filled in the region for forming the next layer after the previous layer is formed, and thus an empty space may be generated. In addition, due to the high viscosity of the material, there is a problem in that the surface may be curved convexly rather than uniformly when the production platform is raised to manufacture the next layer.

13 is an enlarged perspective view for explaining a DLP focus surface according to an embodiment of the present invention. 14 is a perspective view showing a resin tank according to another embodiment of the present invention. 15 is an exemplary diagram for explaining the blade movement and material supply process according to the DLP focal length according to another embodiment of the present invention.

Accordingly, in the bottom-up 3D printing apparatus 1000 according to another embodiment of the present invention, as shown in FIG. 13 , the laser sensor installed at the edge is omitted and the DLP focal length is set using the blade 1230 . It is characterized in that it is fixed. Here, the DLP focal length is parallel to the upper surface of the wall located between the main water tank 1241 formed in the resin tank 1210 and the sub tank 1240 located on both sides of the main water tank 1230 blades 1230 spaced apart from each other. characterized in that it is formed by That is, the DLP focal surface 1250 formed by the blade 1230 is characterized as the top surface of the wall located between the main tank 1241 and the sub tank 1240.

Referring to FIG. 14 , the resin tank 1210 includes a hole H on one side of each sub tank 1240 in which a connection pipe connected to the pump 1260 for material supply and material recovery is mounted. Accordingly, one of the sub-tanks 1241 formed on both sides of the main water tank 1240 may serve as a space for recovering materials and the other for supplying materials, and each role may be changed.

15, first referring to ①, the second sub tank 1241-2 located on one side of the sub tank 1241 disposed on both sides of the main tank 1240 when ^{the first layer (1 st layer) is manufactured.} ) to recover the material and supply the material to the first sub water tank 1241-1 located on the other side. In this case, the amount of material provided from the second sub-tank 1241-2 to the first sub-tank 1241-1 is greater than the total volume of the first sub-tank 1241-1. In other words, the material is supplied until the material overflows the first sub tank 1241-1, but it is characterized in that it is more than an amount sufficient to manufacture at least one layer.

Accordingly, when the material remains after the layer is manufactured, the blade 1230 is moved to the same surface as the DLP focal length measured by the light source unit 1270 and the remaining material is transferred to the sub tank located opposite to the sub tank from which the material was supplied. move it That is, as shown in ②, the amount of material in the second sub-tank 1241-2 is increased by discarding the remaining material remaining by a certain height after the first layer is produced into the second sub-tank 1241-2. will increase

Similarly, after the blade moves to the right through the process from ① to ②, the above-described process is repeated. For example, as shown in ③, the material is recovered from the first sub water tank 1241-1 and the material is supplied to the second sub water tank 1241-2 located on the other side. At this time, the amount of the material provided from the first sub-tank 1241-1 to the second sub-tank 1241-2 is characterized in that it is greater than the total volume of the second sub-tank 1241-2. In other words, the material is supplied until the material overflows the second sub-tank 1241-2, but it is characterized in that the amount is greater than enough to produce at least one layer. Thus, as shown in ④, after making the second layer (2 ^nd layer) by cutting the remaining residual material at a predetermined height in the first sub-tank (1241-1) is in the first sub-tank (1241-1) The amount of material increases.

Therefore, the 3D printing apparatus 1000 according to another embodiment of the present invention has an effect of minimizing a measurement error by fixing the focal length of the DLP without using a laser sensor.

In addition, the 3D printing apparatus 1000 according to another embodiment of the present invention maintains the DLP focal length constant through the movement of the blade, thereby reducing the interference factor due to the high viscosity when the device using the high-viscosity resin makes the next layer. It has the effect of increasing the completeness of

In addition, as the 3D printing apparatus 1000 according to another embodiment of the present invention maintains the DLP focal length constant, even if the height of the material is high, there is no need to descend the manufacturing platform deeply, so it is possible to shorten the time. have.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

Claims (8)

a header for material hardening that linearly moves in the Z-axis direction by a linear actuator; And it is disposed at the bottom of the header for curing the material zirconia (ZrO ₂ ) A heating bat for accommodating a high-viscosity material including; And in the 3D printing device comprising a light source for irradiating ultraviolet light for curing the material in the upper and lower portions of the heating bat,
The heating bat is
a body portion including four side portions, wherein a heatable member for heating the material to a certain temperature or higher to lower the viscosity of the high-viscosity material is inserted into each side portion; and
A bottom-up 3D printing device having a heating bat to control a high-viscosity material, which is disposed under the body part and includes a film fixing part for fixing a release film, which is a transparent member through which the ultraviolet light passes. According to claim 1,
The heatable member is formed with a length corresponding to the height of the side portion and has a long cylindrical shape, a bottom-up 3D printing device having a heating bat to control a high-viscosity material. According to claim 1,
The heatable member has a shape of a heating wire disposed in a band wrapped around the heating bat along the edge of the heating bat, and the heating wire is spaced apart from each other and disposed in parallel to control a high-viscosity material having a heating bat One bottom-up 3D printing device. According to claim 1,
A bottom-up type 3D printing apparatus having a heating bat to control a high-viscosity material, wherein a hole is formed in the center of the lower surface of the body, and the release film transmits light through the hole. According to claim 1,
The light source unit includes: a first light source unit disposed under the fabrication platform disposed at the lower end of the material curing header to irradiate light in an upward direction; and a second light source unit disposed on top of the manufacturing platform to irradiate light in a downward direction, wherein the first light source unit and the second light source unit simultaneously irradiate light to one layer stacked on the manufacturing platform, A bottom-up 3D printing device equipped with a heating bat to control high-viscosity materials. 6. The method of claim 5,
The first light source unit is a DLP projector, and the second light source unit is an LED, a bottom-up 3D printing device having a heating bat to control a high-viscosity material. 6. The method of claim 5,
The heating bat is disposed between the first light source unit and the second light source unit, a bottom-up 3D printing device having a heating bat to control a high-viscosity material. Receiving information on a structure to be manufactured from a computing device through a network communication network;
controlling the movement of a header for material curing fixed to the linear actuator based on the information on the structure; and
When the layers are laminated layer by layer based on the movement of the header for curing the material, it is disposed at the bottom of the header for curing the _{material and accommodating a high-viscosity material containing zirconia (ZrO 2} ) Heating a heating vat (Heating Vat); includes,
A bottom-up type 3D printing device having a heating bat to control the high-viscosity material, in which a heatable member for heating the high-viscosity material to a certain temperature or more is inserted into the side portion of the heating bat to lower the viscosity of the high-viscosity material control method.

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