TWI636867B - Light stereolithography apparatus and method - Google Patents

Abstract

The invention provides a light curing three-dimensional modeling device, which comprises: a tank body, a bottom plate, a holding plate, a lifting mechanism, a light source module, and a control unit. The tank body has a accommodating space for accommodating the photocurable material, and includes: a bottom plate and a wall structure. The bottom plate is transparent or translucent. The wall structure is disposed around the bottom plate and forms the receiving space with the bottom plate. The lifting mechanism is used to move the holding plate up and down. The light source module is disposed below the tank body. The control unit is used to control the light source module and the lifting mechanism. During the formation of a photocured layer of a three-dimensional shaped object, the photocurable material in the cavity is not photocured by the electric field or the magnetic field in the bottom plate, so that the photocured layer is closer to the surface of the bottom plate. The smaller the viscosity.

Description

Light curing stereoscopic molding device and method

The present invention relates to a three-dimensional modeling technique, and more particularly to a photocuring stereoscopic molding technique for manufacturing a three-dimensional object by using a photocurable material.

The photocuring stereoscopic molding technique manufactures a three-dimensional object by stacking a solid thin layer formed by bonding a photocurable liquid resin. Conventional photo-curing stereoscopic modeling machines basically have two conventional practices.

The first method is to project a light pattern from above into the lower tank to cure the liquid photocurable material in the tank. For this top-down configuration, the tank must be sized to maintain sufficient resin to completely immerse the printed object. The surface of the resin needs to be leveled at each layer of exposure to ensure uniformity of each layer. In addition, the surface of the resin does not stay at the same level during printing, and the vertical displacement needs to be compensated to maintain each column of the same thickness. In addition, photocuring occurs on the surface of the resin that is exposed to air, and oxygen suppression causes an increase in the curing time of the resin.

The second method is to project the light pattern upward from the bottom to the transparent bottom of the tank to solidify the liquid photocurable material in the tank. This practice can improve the shortcomings of the above-mentioned photo-curing stereoscopic molding machine, for example, by simplifying the structure of the machine and greatly reducing the volume of the tank body. In addition, a photocurable layer is formed between the bottom of the trough and the front layer or the platform. Since the photocured layer is not formed over the surface of the liquid photocurable material that is exposed to air, the uniformity of the layers and the oxygen suppression problem will no longer exist, and the resin surface leveling device is no longer needed in the machine. Each layer is separated by the bottom of the tank and raised to reserve space for the next layer.

However, due to the extreme force of the Van der Waals, the chemical bonding force and the attraction, the adhesion between the photocured layer and the tank body is caused, which causes the construction platform to have difficulty in drawing the photocured layer. The magnitude of the separation force is positively correlated with the above-mentioned area of the force and photocuring layer and is one of the most important limiting factors for high resolution printing. In order to reduce the adhesion, some techniques to improve the adhesion phenomenon are to provide a flexible film, such as Teflon or silicone, at the bottom of the tank to prevent the photocured layer from sticking to the tank. However, even with such an improvement, the separation force is still too large to be finely printed.

In view of the above problems, an object of the present invention is to provide a photocuring three-dimensional modeling apparatus and method. In the photocuring stereoscopic molding technique of the present invention, by using a charged body (for example, a cationic group, a charged monomer or an oligomer) which can form a photocurable material during photocuring. A technique that is moved to a surface other than the surface of the bottom plate to achieve a smaller viscosity of the photocured layer that brings the three-dimensional shaped object closer to the surface of the holding plate.

In one embodiment of the present invention, a photocuring stereoscopic molding device is provided, which comprises a tank body, a bottom plate, a holding plate, a lifting mechanism, a light source module, and a control unit. The tank body has a accommodating space for accommodating the photocurable material, and includes: a bottom plate and a wall structure. The bottom plate is transparent or translucent. The wall structure is disposed around the bottom plate and forms the receiving space with the bottom plate. The lifting mechanism is used to move the holding plate up and down. The light source module is disposed below the tank body. The control unit is used to control the light source module and the lifting mechanism. In the photocuring stereoscopic molding device, the photocuring material is photocured by irradiation with the light source module, and after forming a photocurable layer on the holding plate, the holding plate is moved by the lifting mechanism, and then returned. The photo-curing layer is formed by the above-described light irradiation, and further formed into a three-dimensional shaped object layer by layer. During the formation of the photocured layer, by using an electric or magnetic field at the bottom plate The photocurable material in the bath body is not photocured on the surface of the bottom plate, so that the viscosity of the photocured layer closer to the surface of the bottom plate is smaller.

In another embodiment of the present invention, a photocuring stereoscopic modeling method is provided, the method comprising the following steps. A light curing stereoscopic molding device is provided. An electric field or a magnetic field is formed on one of the bottom plates of one of the light-curing three-dimensional modeling devices. The photocuring material is photocured by irradiation of a light source module of the photocuring stereoscopic molding device, and a photocured layer is formed on the holding plate, and then the lifting mechanism is moved by the lifting mechanism of the photocuring stereoscopic molding device. The plate is then subjected to the light irradiation to form a photocured layer, and then formed into a three-dimensional shaped object layer by layer; wherein during the formation of the photocured layer, the light is solidified in the cavity by using an electric field or a magnetic field on the bottom plate The material does not photocuring on the surface of the substrate, so that the viscosity of the photocured layer closer to the surface of the substrate is smaller.

For a better understanding of the above and other aspects of the present invention, reference should be made

100‧‧‧Light curing stereo modeling device

110‧‧‧ tank

111‧‧‧floor

111P‧‧‧ surface of the bottom plate

112‧‧‧ wall structure

120‧‧‧holding board

130‧‧‧ Lifting mechanism

140‧‧‧Light source module

150‧‧‧Control unit

180‧‧‧ accommodating space

190‧‧‧Photocuring materials

199‧‧‧Three-dimensional object

200‧‧‧Substrate

201‧‧‧First conductive layer

202‧‧‧Second conductive layer

FD‧‧‧Physical Field

ED‧‧ electric field

1 shows a schematic view of a photocuring stereoscopic molding apparatus in accordance with an embodiment of the present invention.

2A and 2B show schematic views of photocuring that does not occur on the surface of the substrate by an embodiment of the present invention.

Figure 3 is a partial cross-sectional view showing a tank body in an embodiment of the present invention.

Figure 4 is a partial cross-sectional view showing a tank body in an embodiment of the present invention.

Figure 5 is a partial cross-sectional view showing a tank body in an embodiment of the present invention.

6 shows a schematic diagram of a photocuring stereoscopic modeling method in accordance with an embodiment of the present invention.

The present invention proposes to use a charged body (for example, a cationic group, a charged monomer or an oligomer, etc.) which can form a photocurable material during photocuring in a photocuring stereoscopic molding technique. A technique other than the surface of the bottom plate achieves the effect of making the solidified layer of the three-dimensional shaped object closer to the surface of the holding plate less viscous.

Hereinafter, various embodiments of the present invention will be described by taking the structure of the photocuring stereoscopic molding apparatus as an example in accordance with the above aspects of the present invention.

1 shows a schematic view of a photocuring stereoscopic molding apparatus in accordance with an embodiment of the present invention. As shown in FIG. 1 , the photo-curing stereoscopic molding apparatus 100 includes at least a tank body 110 , a holding plate 120 , a lifting mechanism 130 , a light source module 140 , and a control unit 150 . The tank body 110 has an accommodating space 180 for accommodating the photocurable material 190. The lifting mechanism 130 is for moving the holding plate 120 up and down. The light source module 140 is disposed below the tank body 110. The control unit 150 is used to control the light source module 140 and the lifting mechanism 130. In addition, the tank body 110 includes a bottom plate 111 and a wall structure 112. The bottom plate 111 is transparent or translucent; the wall structure 112 is disposed around the bottom plate 111 and forms the receiving space 180 with the bottom plate 111.

In the photo-curing stereoscopic molding apparatus 100, the photocuring material 190 is photocured by the light source module 140, and after the photocuring layer is formed on the holding plate 120, the holding plate is moved by the elevating mechanism 130. 120. Then, the light is irradiated to form a photocured layer, and then a three-dimensional shaped object 199 is formed layer by layer.

In the photocuring stereoscopic molding apparatus 100 illustrated in FIG. 1, during the formation of the photocured layer, a physical field FD such as an electric field or a magnetic field is utilized or formed in the bottom plate 111 (for example, a physical field exists in a space indicated by a broken line) The photocurable material 190 in the tank body 110 is not photocured on the surface of the bottom plate, so that the viscosity of the photocured layer closer to the surface of the bottom plate is smaller. Thereby, the photocuring stereoscopic molding device according to the present invention can prevent the photocurable material from being affected by the surface of the bottom plate Curing and adhering to the surface of the bottom plate makes it difficult to draw the solidified layer of the three-dimensional shaped object formed by the three-dimensional modeling technique.

In conventional photocuring stereoscopic modeling techniques, photocurable materials such as photoinitiators in "photopolymers" generate free radicals after absorbing ultraviolet light (eg, ultraviolet light having a wavelength of 250-300 nm) or A cationic group which is cured by crosslinking polymerization with a monomer and a corresponding oligomer (oligomer) in the photosensitive resin. As shown in FIG. 2A, in the photocuring stereoscopic molding apparatus 100, during the formation of the photocured layer, it is assumed that when the bottom plate 111 does not utilize an electric field or a magnetic field, the cationic group is concentrated on the surface 111P of the bottom plate 111 and further solidified. Adhesion to the surface 111P of the bottom plate 111 causes conventional sticking problems.

As shown in FIG. 2B, in the photocuring stereoscopic molding apparatus 100, during the formation of the photocured layer, when the bottom plate 111 utilizes the electric field ED, the charged body such as a cation group is subjected to an electric field ED (for example, an anodic upward electric field direction). The generated repulsive force is applied to the surface 111P of the bottom plate 111 to continue the curing reaction. In addition, when a magnetic field is applied to the surface 111P of the bottom plate 111, since the charged body in the photocurable material is subjected to a magnetic field (for example, a magnetic field line is a surface 111P surrounding the bottom plate 111), the photocurable material does not interact with the bottom plate. The surface 111P of the 111 is brought into contact, so that the curing reaction can be sequentially performed layer by layer. Thereby, embodiments of the present invention enable photocuring to not occur on the surface of the substrate.

An example in which the aforementioned bottom plate 111 utilizes an electric field or a magnetic field will be exemplified below.

Figure 3 is a partial cross-sectional view showing a tank body in an embodiment of the present invention. In FIG. 3, the bottom plate 111 includes a first conductive layer 201. During the formation of the photo-cured layer, a magnetic field is formed by applying a voltage (for example, by using a power source VS) on both sides of the first conductive layer 201 of the bottom plate 111, so that the photo-curing material 190 in the cavity 110 is not in the The surface of the bottom plate 111 is photocured so that the viscosity of the photocured layer closer to the surface of the bottom plate 111 is smaller.

Figure 4 is a partial cross-sectional view showing a tank body in an embodiment of the present invention. In FIG. 4, the bottom plate 111 includes a substrate 200 and a first conductive layer 201. During the formation of the photo-cured layer, the light is formed by applying a voltage to the two sides of the first conductive layer 201 of the bottom plate 111 (for example, by using a power source VS) to form a magnetic field. The cured material 190 does not photocuring on the surface of the bottom plate 111, so that the viscosity of the photocured layer closer to the surface of the bottom plate 111 is smaller.

In addition, since the magnitude of the current is positively correlated with the magnitude of the magnetic field generated by the current in the current magnetic effect, the photocurable material 190 can be achieved by adjusting the magnitude of the current passing through the first conductive layer 201 to apply an appropriate magnetic field. The effect of photocuring does not occur on the surface of the bottom plate 111.

Figure 5 is a partial cross-sectional view showing a tank body in an embodiment of the present invention. In FIG. 5, the bottom plate 111 includes a substrate 200, a first conductive layer 201, and a second conductive layer 202. The first conductive layer 201 is disposed between the photocurable material 190 and the substrate 200 disposed in the trench 110; the substrate 200 is disposed between the first conductive layer 201 and the second conductive layer 202. During formation of the photo-cured layer, the electric field is solidified by charging between the first conductive layer 201 and the second conductive layer 202 (such as a positive voltage is applied by the power source VS) to cure the light in the cavity 110. The material 190 is not photocured on the surface of the bottom plate 111, so that the viscosity of the photocured layer closer to the surface of the bottom plate 111 is smaller.

In addition, the electric field size E _ab between the first conductive layer 201 and the second conductive layer 202 can be simplified by using the formula E _ab =V _ab /d, where V _ab is expressed and applied to the first conductive layer 201 and The voltage of the second conductive layer 202, d, represents the distance between the two. Therefore, the effect of the photocurable material 190 not being photocured on the surface of the bottom plate 111 can be achieved by adjusting the size of V _ab or d to generate an electric field of an appropriate magnitude.

In addition, in the above-described FIGS. 3 to 5, the first conductive layer 201 may be a transparent conductive film; the substrate 200 may be glass, ceramic, or any A suitable transparent or translucent substrate is achieved. Furthermore, the substrate 200 and the first conductive layer 201 (and/or the second conductive layer 202) can be realized by using conductive oxide (TCO) glass, for example, Indium Tin Oxide (ITO). Glass, fluorine-doped tin oxide (FTO; Florine Doped Tin Oxide) conductive glass, aluminum-doped zinc oxide (AZO; Al-doped ZnO) conductive glass, zinc oxide-doped gallium (GZO; Ga. Zno) conductive glass, indium oxide It is realized by one of zinc (IZO; Indium Zinc Oxide) conductive glass and zinc oxide (ZnO; Zinc Oxide) conductive glass. In addition, the conductive layer (the first conductive layer 201 and/or the second conductive layer 202) in any of the above embodiments may also be made of a conductive polymer material, a carbon nanotube material, a nanoparticle material, or a metal naphthalene. Rice wire and other materials to achieve. In short, any material having good light transmittance and conductivity can be used as the material of the conductive layer in the above embodiment as long as it can generate an electric field or a magnetic field after being energized.

In an embodiment of any of the foregoing photo-curing stereoscopic molding devices, the light source module can use an ultraviolet light source. The present invention is not limited to the light source module, as long as it can be used to generate a light source module for a plurality of cross-sectional layers of the three-dimensionally shaped object.

In addition, in order to further reduce the aforementioned photo-curing adhesion problem, in any of the foregoing embodiments of the photo-curing stereoscopic molding apparatus, one of a visible light source, a visible light laser source, and an infrared light source may be used, wherein Irradiation of the source causes a photocuring reaction of the suitable photocurable material. Compared with the conventional patterned light source using ultraviolet light as a photocuring stereoscopic modeling device, a long-wavelength light source other than ultraviolet light such as a visible light source (for example, a wavelength of 400 nm to 760 nm) or an infrared light source (for example, a wavelength of 760 nm) is used. At 10000 nm), since the transmittance of the long-wavelength light source to the liquid is higher than that of the ultraviolet light, the hardening degree of the photocurable material on the surface of the bottom plate 111 after the long-wavelength light source is irradiated through the bottom plate 111 is smaller than that. The degree of hardening of the photocurable material outside the bottom plate 111, whereby the pulling force of the solidified layer is relatively lowered.

6 shows a schematic diagram of a photocuring stereoscopic modeling method in accordance with an embodiment of the present invention. In Fig. 6, as shown in step S110, a photocuring stereoscopic molding apparatus is provided. As shown in step S120, an electric field or a magnetic field is formed on one of the bottom plates of one of the light-solidified three-dimensional modeling devices. As shown in step S130, the photocuring material is photocured by the light source module of the photocuring stereoscopic molding device, and a photocured layer is formed on the holding plate, and then the photocuring stereoscopic molding device is used. A lifting mechanism moves the holding plate, and then the light is irradiated to form a photo-cured layer, thereby forming a three-dimensional shaped object layer by layer. During the formation of the photo-cured layer, the photocuring material in the bath body is not photo-cured by the electric field or the magnetic field in the bottom plate, so that the viscosity of the photo-cured layer closer to the surface of the bottom plate is obtained. The smaller.

In the photocuring stereoscopic molding method described above, during the formation of the photocurable layer, a magnetic field is formed by energizing one of the first conductive layers of the substrate, so that the photocurable material in the cavity is not photocured on the surface of the substrate. The viscosity of the photocured layer closer to the surface of the substrate is made smaller.

In the photocuring stereoscopic molding method described above, during the formation of the photocurable layer, an electric field is formed by charging the opposite conductive layers of the bottom plate, so that the photocurable material in the cavity is not photocured on the surface of the substrate. The viscosity of the photocured layer closer to the surface of the substrate is made smaller.

In the above photocuring stereoscopic modeling method, the light source module illuminates one of visible light, visible light laser, and infrared light ray to cause a photocuring reaction of the photocurable material.

In the above-described photocuring three-dimensional modeling method, it can also be realized by referring to any of the above embodiments of the photocuring three-dimensional modeling apparatus.

In summary, the content of the present invention has been exemplified by the above embodiments, but the present invention is not limited to the embodiments. It will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit and scope of the invention. For example, the technical contents illustrated in the foregoing embodiments may be combined or changed. As a new embodiment, these embodiments are of course considered as one of the contents of the present invention. Therefore, the scope of the patent to be protected in this case also includes the scope of the patent application and the scope defined by it.

Claims (8)

A light-curing stereoscopic molding device, comprising: a tank body having an accommodating space for accommodating a photocurable material, the tank body comprising: a bottom plate which is transparent or translucent; and a wall structure, the setting Forming the accommodating space around the bottom plate and the bottom plate; a holding plate; a lifting mechanism for moving the holding plate; a light source module disposed under the groove; and a control unit The light source module and the lifting mechanism are controlled; wherein in the photocuring stereoscopic molding device, the photocuring material is photocured by irradiation of the light source module, and a photocured layer is formed on the holding plate. And moving the holding plate with the lifting mechanism, and then performing the light irradiation to form a photo-cured layer, and then forming a three-dimensional shaped object layer by layer; and during the forming of the photo-cured layer, by using a magnetic field in the bottom plate The photocurable material in the bath body is not photocured on the surface of the bottom plate, so that the viscosity of the photocured layer closer to the surface of the bottom plate is smaller. The photocuring stereoscopic molding device of claim 1, wherein the bottom plate comprises a first conductive layer; and during the forming of the photocurable layer, the magnetic field is formed by energizing the first conductive layer of the bottom plate to make the magnetic field The photocurable material in the bath is not photocured on the surface of the bottom plate, so that the viscosity of the photocured layer closer to the surface of the bottom plate is smaller. The photo-curing stereoscopic molding device of claim 2, wherein the bottom plate further comprises a substrate, the first conductive layer being disposed between the photocurable material and the substrate received by the cavity. The photocuring stereoscopic molding apparatus according to claim 3, wherein the substrate is glass or ceramic. The light-curing stereoscopic modeling device according to any one of claims 1 to 3, wherein the light source module comprises: a visible light source, a visible light laser source, and an infrared light source, wherein the light source is The irradiation causes the photocurable material to undergo a photocuring reaction. A photocuring stereoscopic molding method, comprising: providing a photocuring stereoscopic molding device; forming a magnetic field on a bottom plate of one of the cavity bodies of the photocuring stereoscopic molding device; and illuminating the light source module through one of the photocuring stereoscopic molding devices The photocuring material undergoes a photocuring reaction, and after forming a photocured layer on the holding plate, the holding plate is moved by a lifting mechanism of the photocuring stereoscopic molding device, and then the light is irradiated to form a photocured layer, and then Layered into a three-dimensional shaped object; wherein during the formation of the photo-cured layer, the light-curing material in the cavity is not photo-cured in the cavity by using a magnetic field on the substrate, so that the light is closer to the surface of the substrate The viscosity of the cured layer is smaller. The photocuring stereoscopic molding method according to claim 6, wherein during the forming of the photocured layer, a magnetic field is formed by energizing one of the first conductive layers of the bottom plate, so that the photocurable material in the cavity is not in the bottom plate. The surface is photocured so that the viscosity of the photocured layer closer to the surface of the substrate is smaller. The photocuring stereoscopic molding method according to any one of claims 6 to 7, wherein the light source module illuminates one of visible light, visible light laser, and infrared light ray to cause a photocuring reaction of the photocurable material.