阅读说明：本技术 立体打印方法 (three-dimensional printing method ) 是由 赵伟淳 郭宗桦 丁明雄 于 2018-05-28 设计创作，主要内容包括：本发明提供一种立体打印方法,包括：取得液态成型材的波长-吸收率关系,且所述关系包含至少两个对应波长的吸收率峰值；通过立体打印装置成型立体物件,其中立体打印装置提供第一光线将液态成型材逐层固化并堆叠为立体物件,且第一光线的波长是至少两个对应波长的其中之一；以及通过后固化装置提供第二光线照设立体物件,且第二光线具有所述至少两个对应波长。(the invention provides a three-dimensional printing method, which comprises the following steps: obtaining a wavelength-absorptivity relation of the liquid molding material, wherein the relation comprises at least two absorptivity peaks corresponding to the wavelengths; forming a three-dimensional object by a three-dimensional printing device, wherein the three-dimensional printing device provides first light to solidify and stack the liquid forming material layer by layer into the three-dimensional object, and the wavelength of the first light is one of at least two corresponding wavelengths; and providing a second light ray through the post-curing device to illuminate the three-dimensional object, wherein the second light ray has the at least two corresponding wavelengths.)

1. a method of stereoscopic printing, comprising:

Obtaining a wavelength-absorptivity relation of the liquid molding material, wherein the relation comprises at least two absorptivity peaks corresponding to the wavelengths;

Forming a three-dimensional object by a three-dimensional printing device, wherein the three-dimensional printing device provides a first light to solidify liquid forming materials layer by layer to form the three-dimensional object in a stacking mode, and the wavelength of the first light is one of the at least two corresponding wavelengths; and

And providing a second light ray to irradiate the three-dimensional object through a post-curing device, wherein the second light ray has the at least two corresponding wavelengths.

2. The method of claim 1, wherein the first light has a wavelength that corresponds to a higher of the absorbance peaks.

3. the stereoscopic printing method of claim 1, wherein the wavelength of the first light is longer than the at least two corresponding wavelengths.

4. the stereoscopic printing method of claim 1, wherein a wavelength of the first light is greater than or equal to the at least two corresponding wavelengths of the second light.

5. The stereoscopic printing method of claim 1, wherein the intensity of the first light is less than the intensities of the at least two corresponding wavelengths of the second light.

6. The stereoprinting method according to claim 1, wherein intensities of the at least two corresponding wavelengths of the second light are proportional to an absorption rate of the liquid molding material.

7. The stereoprinting method according to claim 1, wherein the irradiation time of the at least two corresponding wavelengths of the second light is inversely proportional to the absorbance of the liquid molding material.

8. The stereoscopic printing method according to claim 1, wherein the post-curing device comprises:

A body having a cavity;

The control unit and the plurality of light-emitting elements are respectively arranged on the machine body, the light-emitting elements are electrically connected with the control unit, so that the control unit controls and adjusts the irradiation time and the intensity of the second light, the three-dimensional object is suitable for being placed in the cavity, and the control unit drives the light-emitting elements to provide the second light to irradiate the three-dimensional object in the cavity.

9. the stereoscopic printing method according to claim 8, wherein the light emitting elements are arranged in different areas above the chamber according to the wavelengths of light thereof.

10. the stereoscopic printing method according to claim 8, wherein the light emitting elements are arranged around different areas of the periphery of the chamber according to the wavelengths of light.

11. the stereographic printing method according to claim 8, wherein said post-curing device further comprises a rotating base disposed on said body at a bottom of said chamber, said stereographic object being adapted to be placed on said rotating base.

12. The stereoscopic printing method according to claim 1, comprising:

For different liquid molding materials, storing the wavelength of the first light corresponding to the different liquid molding materials in the three-dimensional printing device; and

Storing the at least two corresponding wavelengths of the corresponding second light to the post-cure device.

13. the stereoscopic printing method according to claim 12, comprising:

Storing the intensities or irradiation times of the at least two corresponding wavelengths of the corresponding second light rays in the post-curing device.

Technical Field

the invention relates to a three-dimensional printing method.

Background

with the development of science and technology, various methods for building a physical three-dimensional (3-D) model by using additive manufacturing technology (additive manufacturing technology) such as a layer-by-layer building model have been proposed. In general, additive manufacturing techniques convert design data of 3D models constructed using software such as computer-aided design (CAD) into a plurality of thin (quasi-two-dimensional) cross-sectional layers that are stacked in series.

Many ways have been developed in which multiple thin cross-sectional layers can be formed. For example, photosensitive resin (photopolymer) is used as a liquid molding material for most three-dimensional printing devices, and the liquid molding material is solidified into a correct cross-sectional layer shape by disposing a moving platform in the liquid molding material and driving a light source to move along X-Y coordinates according to X-Y-Z coordinates constructed by design data of a 3D model to irradiate the liquid molding material. Then, as the moving platform moves along the Z axis, the liquid molding material can form a three-dimensional object on the moving platform under the state of layer-by-layer solidification and stacking.

however, in the actual manufacturing process, the liquid molding material has the absorption rate corresponding to different wavelengths of light due to the material characteristics, that is, the absorption rate of the liquid molding material to the light changes with the different wavelengths of light, so that the liquid molding material cannot be completely cured by only using the light with a single wavelength. For the three-dimensional printing device, in addition to the single wavelength curing light source, the curing light source cannot cover all wavelengths of light for curing the liquid molding material, and moreover, the liquid molding material has absorption rates corresponding to different wavelengths, so that a state that the three-dimensional object cannot be completely cured easily exists, and the quality of three-dimensional printing is reduced.

Accordingly, how to provide a perfect curing process in the process of manufacturing the three-dimensional object to improve the above situation becomes a subject to be considered and solved by those skilled in the art.

Disclosure of Invention

the invention aims at a three-dimensional printing method, and a three-dimensional object can reach a completely cured state through different curing means.

According to an embodiment of the present invention, a stereoscopic printing method includes: obtaining a wavelength-absorptivity relation of the liquid molding material, wherein the relation comprises at least two absorptivity peaks corresponding to the wavelengths; forming a three-dimensional object by a three-dimensional printing device, wherein the three-dimensional printing device provides a first light to solidify liquid forming materials layer by layer to form the three-dimensional object in a stacking mode, and the wavelength of the first light is one of the at least two corresponding wavelengths; and providing second light rays to irradiate the three-dimensional object through a post-curing device, wherein the second light rays have the at least two corresponding wavelengths.

Based on the above, the present invention determines the light characteristics required for forming and curing the three-dimensional object according to the wavelength-absorption ratio relationship of the liquid forming material, and further adjusts and matches the light with the required characteristics. That is, after the wavelength-absorptance relationship of the liquid molding material is obtained, the number of absorptance peaks corresponding to the wavelength and the corresponding wavelength can be known, so that the molding process of the three-dimensional object can be performed by the first light, wherein the wavelength of the first light is one of the corresponding wavelengths. And then, placing the molded three-dimensional object into a post-curing device, and carrying out a post-curing process on the three-dimensional object by using second light provided by the post-curing device, wherein the second light has corresponding wavelengths comprising the at least two peaks.

in other words, in the process of executing the molding process, the first light only needs to include the light wavelength enough for molding, and then in the process of the post-curing process, the post-curing device can provide the light with all the corresponding absorption wavelengths of the liquid molding material so as to completely cure the three-dimensional object. Therefore, the problem that the absorptivity of the existing liquid molding material is different along with different light wavelengths can be effectively solved, and the three-dimensional object can absorb all light wave bands which are enough to be solidified.

Drawings

the accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

FIG. 1 is a schematic flow chart of a stereoscopic printing method according to an embodiment of the invention;

FIG. 2 is a schematic view showing a wavelength-absorption ratio relationship of a liquid molding material according to an embodiment of the present invention;

FIGS. 3A and 3B are schematic views of a three-dimensional printing apparatus according to an embodiment of the invention;

FIG. 3C is an electrical diagram of some components of the three-dimensional printing apparatus;

FIG. 3D is a graph showing the wavelength-intensity relationship of a light-emitting element;

FIGS. 4A and 4B are schematic views of a post-curing device according to an embodiment of the invention;

FIG. 4C is a diagram of electrical connections of a post-cure device;

FIG. 5 is a schematic view of a post-cure apparatus according to another embodiment of the present invention.

description of the reference numerals

100: a stereoscopic printing device;

110: a body;

112: a base;

114: a gantry;

120: a containing groove;

130: a forming platform;

140: a curing light source;

142: a light emitting element;

144: an optical element;

151. 152: a drive unit;

160: a control unit;

200. 200A: a post-curing device;

210: a body;

211: a bottom;

211 a: rotating the base;

212. 213: a side portion;

214: a top portion;

215: a chamber;

220: a control unit;

231: a first light emitting element;

232: a second light emitting element;

233: a third light emitting element;

230A: light emitting element

l1: a first light ray;

L1 a: light rays;

L2: a second light ray;

p1, P2, P3, P4, P5, P6: peak value

R1, R2: liquid forming material

S01, S02, S03: a step of;

X-Y-Z: rectangular coordinates.

Detailed Description

Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

fig. 1 is a flowchart illustrating a stereoscopic printing method according to an embodiment of the invention. FIG. 2 is a schematic view showing a wavelength-absorption ratio relationship of a liquid molding material according to an embodiment of the present invention. Referring to fig. 1 and 2, in the process of three-dimensional printing, since the material property of the liquid molding material and the absorption rate of the curing light varies with the wavelength, in order to overcome the above-mentioned problem, the three-dimensional object can be completely cured, in the three-dimensional printing method of the present invention, first, in step S01, the wavelength-absorption rate relationship of the liquid molding material is obtained, that is, the information shown in fig. 2 is obtained, and referring to the liquid molding material R1, it can be known from the relationship that the liquid molding material R1 has three peak values (peak) P1, P2 and P3 corresponding to the wavelength of the absorption rate, wherein P1> P2> P3 represents that the liquid molding material R1 has a larger absorption rate for the light with a wavelength of 385nm, and then the light with a wavelength of 365nm and the light with a wavelength of 405nm are sequentially obtained. That is, the curing lights with the 3 wavelengths can cure the liquid molding material smoothly, wherein the difference is the intensity and the irradiation time required by the curing lights.

It should be noted that, as shown in fig. 2, the peak P3 is not obvious (the absorption rate is lower) compared to the peaks P1 and P2, so that in other embodiments not shown, one of the peaks P1 and P2 may be selected as the basis for the curing light, which will be described in detail later.

fig. 3A and 3B are schematic views of a three-dimensional printing apparatus according to an embodiment of the invention. Fig. 3C is an electrical relationship diagram of a part of components of the three-dimensional printing apparatus, wherein a dotted line represents a non-electrical connection relationship. Referring to fig. 3A to 3C and comparing fig. 1 and 2, the stereo printing apparatus 100 is, for example, a Stereo Lithography Apparatus (SLA), which comprises a body 110, a containing groove 120, a forming platform 130, a curing light source 140, driving units 151 and 152 and a control unit 160, wherein the body 110 includes a base 112 and a gantry 114 disposed on the base 112, the container 120 is used for containing a liquid molding material (such as the liquid molding material R1), the curing light source 140 is disposed in the base 112 and below the container 120, the curing light source 140 includes a light emitting element 142 and an optical element 144, the control unit 160 is electrically connected to the light emitting element 142 of the curing light source 140 to generate a light L1a, and forms the first light L1 after passing through the optical element 144, and the control unit 160 can also control the light emitting diode by driving the optical element 144, for example, the focal length of the light or the irradiation and scanning positions are adjusted to complete the solidification of the liquid molding material R1 at a specific position.

Furthermore, the forming platform 130 is movably disposed on the gantry 114 through the driving unit 151, and the control unit 160 is electrically connected to the driving unit 151 to drive the forming platform 130 to move along the Z-axis, so as to move into or out of the containing slot 120.

After the forming platform 130 moves into the containing groove 120 and contacts the liquid forming material, the curing light source 140 provides a first light L1 to pass through the bottom of the transparent containing groove 120 to cure and form the liquid forming material R1 on the forming surface of the forming platform 130 layer by layer, and as the forming platform 130 gradually moves away from the containing groove 120, the solid forming layers cured layer by the liquid forming material R1 can be gradually stacked on the forming platform 130 until the printing of the three-dimensional object is completed. It should be noted that only the components and the related three-dimensional printing process related to the present invention are listed here, and the other non-disclosed people can be known from the existing three-dimensional lithography technology, and thus the details are not repeated.

fig. 3D is a schematic wavelength-intensity relationship diagram of the light-emitting element. Referring to fig. 3D, in the present embodiment, the light emitting device 142 of the curing light source 140 is, for example, a Light Emitting Diode (LED), and due to the monochromatic light characteristics of the LED, three different peak values shown in fig. 3D respectively represent the wavelengths of light generated by three different light emitting devices, and are also used to correspond to the wavelength-absorption ratio relationship of the liquid molding material R1 shown in fig. 2. It should be noted that the light with lower wavelength is not only required to be smoothly controlled by the optical element with higher precision, but also easily damages the object passing through the optical element. That is, in the three-dimensional printing apparatus 100 shown in fig. 3A and 3B, the optical element 144 and the containing groove 120 are both located on the light path of the light L1a generated by the light emitting element 142 and the first light L1, and once the light emitting element 142 with a lower wavelength is selected, not only the manufacturing cost of the optical element 144 is increased, but also the service life of the optical element 144 and the containing groove 120 is reduced and the maintenance cost is increased because the optical element 144 and the containing groove 120 are easily damaged.

In view of the above, in addition to the stereo printing apparatus 100, the present invention further provides a post-curing apparatus 200, and fig. 4A and 4B are schematic diagrams of the post-curing apparatus according to an embodiment of the present invention. FIG. 4C is a diagram of electrical connections of the post-cure device. Referring to fig. 4A to 4C, the post-curing device 200 includes a body 210, a plurality of light emitting elements and a control unit 220, the body 210 is composed of a bottom 211, sides 212 and 213, and a top 214, and thus forms a chamber 215 for accommodating three-dimensional objects, wherein the side 212 is openably and closably assembled to the side 213, so that a user can open or close the chamber 215. As shown in fig. 4B and 4C, the light-emitting elements are controlled by the control unit 220 to provide a second light L2 to perform a post-curing process on the three-dimensional object in the cavity 215, and the light-emitting elements include a first light-emitting element 231, a second light-emitting element 232 and a third light-emitting element 233, which are respectively disposed on the top 214 of the body 210 and electrically connected to the control unit 220, so that the control unit 220 can turn on and off the light-emitting elements, and accordingly, the output power (which can be regarded as the irradiation intensity of the second light L2) and the irradiation time of the light-emitting elements are adjusted. Here, the first light emitting element 231, the second light emitting element 232 and the third light emitting element 233 generate light with different wavelengths, as shown in fig. 3D, the first light emitting element 231 is used for generating light with a wavelength of 385nm, the second light emitting element 232 is used for generating light with a wavelength of 365nm, and the third light emitting element 233 is used for generating light with a wavelength of 405nm, that is, the light emitting elements are arranged in different areas above the chamber 215 according to the wavelengths of the light, so that the second light L2 can include at least one of the light with the wavelengths. It should be noted that although the present embodiment shows three different wavelength bands of light, the present invention is not limited to the number of wavelength bands.

In addition, the post-curing device 200 of the present embodiment further includes a rotating base 211a disposed at the bottom 211 of the body 210 and located at the bottom of the cavity 215, and the formed three-dimensional object is suitable for being placed on the rotating base 211a, so that when the post-curing process is performed, the three-dimensional object can be driven by the rotating base 211a to rotate in the cavity 215, so as to increase the surface area of the three-dimensional object irradiated by the second light L2.

the arrangement of the light emitting elements in the post-curing device is not limited herein. FIG. 5 is a schematic view of a post-cure apparatus according to another embodiment of the present invention. Unlike the previous embodiments, in the post-curing device 200A of the present embodiment, the light emitting elements 230A are disposed around different areas of the periphery of the chamber according to the wavelength of the light. Thus, the three-dimensional object can be received by the light generated by the surrounding light-emitting elements 230A after being placed in the chamber.

Referring to fig. 1 and fig. 2 and 3D, as mentioned above, in order to avoid the above-mentioned problem caused by using light with a lower wavelength in the three-dimensional printing process, the curing device 200 is combined with the three-dimensional printing device 100 to form the three-dimensional printing method shown in fig. 1. It should be noted that the following selection of the light wavelength band by the stereo printing method is only an example, and those skilled in the art can deduce other related embodiments by the selection logic.

In step S01, the wavelength-absorptance relationship of the liquid molding material R1 is obtained, and as shown in fig. 2, the relationship includes at least two absorptance peaks corresponding to the wavelengths, here, three absorptance peaks P1, P2, and P3 are taken as an example; next, in step S02, a three-dimensional object is formed by the three-dimensional printing apparatus 100, wherein the three-dimensional printing apparatus 100 provides a first light L1 to solidify the liquid forming material R1 layer by layer to form the three-dimensional object, and the wavelength of the first light L1 is one of the at least two corresponding wavelengths, where the higher of the absorptance peaks P1, P2 and P3, that is, the light with the corresponding wavelength (385nm) of the absorptance peak P1, is selected as the light emitting element 142 required for forming the three-dimensional object, as shown in fig. 3D.

In another embodiment, not shown, the light with the longer wavelength, i.e., the light with the wavelength of 405nm corresponding to the absorptance peak P3, can be selected from the absorptance peaks P1, P2 and P3 as the light emitting element 142 of the stereo printing apparatus 100.

as mentioned above, the peak absorbance P3 is lower and less obvious than the peak absorbance P1, P2, so in another embodiment not shown, the peak absorbance P1 and P2 are used as the basis for selection, but similarly, the peak absorbance P1 is used as the curing light source 140 for the three-dimensional printing process, and the corresponding wavelength is longer.

based on the above, it can be clearly seen that, in the three-dimensional printing method of the present invention, after the wavelength-absorbance relationship of the liquid molding material R1 is obtained, the higher one corresponding to the peak absorbance value or the longer one corresponding to the wavelength (or both of the above conditions) is selected as the curing light source 140 required by the three-dimensional printing apparatus 100 for molding the three-dimensional object, so as to prevent the shorter wavelength light from easily damaging the optical element 144 and the containing groove 120, thereby increasing the service life and reducing the maintenance cost.

next, in step S03, the molded three-dimensional object is moved into the cavity 215 of the post-curing device 200, and a second light L2 is provided by the post-curing device 200 to irradiate the three-dimensional object, wherein the second light L2 has the at least two corresponding wavelengths, and in this embodiment, the wavelength of the second light L2 is the corresponding wavelength including the three absorption peaks P1, P2 and P3 of the liquid molding material R1.

In detail, as can be seen from the comparison between the three-dimensional printing apparatus 100 and the post-curing apparatus 200, the three-dimensional printing apparatus 100 can complete the three-dimensional printing process of the three-dimensional object by using the optical element to control the first light L1 to irradiate the specific position of the liquid molding material R1 in the container 120. However, the post-curing device 200 is used to re-cure the molded three-dimensional object, so the light-emitting device does not need to be installed with the optical device 144 for guiding or focusing light, that is, the light-emitting device generates light and does not pass through any intermediate object in the process of irradiating the three-dimensional object, and thus there is no concern of damaging the object. Accordingly, the post-curing device 200 can be configured with the first light emitting element 231, the second light emitting element 232 and the third light emitting element 233 with different wavelengths, so that the wavelength of the second light L2 can include the corresponding wavelengths of all the peaks (P1, P2 and P3) of the liquid molding material R1 in the wavelength-absorption relationship, as shown in fig. 3D. In this way, the three-dimensional object moving into the cavity 215 can receive the multi-band second light L2, thereby achieving the fully cured state.

It should be noted that, for the convenience of the user, the three-dimensional printing method of the present embodiment further includes: for the different liquid molding materials, storing the corresponding wavelength (or the relevant parameter) of the first light L1 in the stereo printing device 100; and storing the at least two corresponding wavelengths (or their related parameters) corresponding to the second light L2 in the post-curing device 200. Further, the intensities or irradiation times of at least two corresponding wavelengths of the second light L2 are stored in the post-curing device 200. In this way, when the user performs the three-dimensional printing again, the required parameters such as wavelength, intensity, and irradiation time can be directly taken from the three-dimensional printing apparatus 100 and the post-curing apparatus 200, so as to simplify the operation procedure of the user and improve the three-dimensional printing efficiency.

The following describes the light ray using means of the three-dimensional printing method according to the present invention with reference to fig. 2 and 3D in different embodiments:

in an embodiment, a user may first use the wavelength 405nm corresponding to the absorbance peak P3 as the first light L1 required by the three-dimensional printing apparatus 100 to form the three-dimensional object, and then perform a post-curing process on the formed three-dimensional object by using the second light L2 including the absorbance peaks P1, P2, and P3 corresponding to the wavelengths 385nm, 365nm, and 405nm through the post-curing apparatus 200, so in this embodiment, the wavelength of the first light L1 is greater than or equal to the wavelength of the second light L2.

In one embodiment, the user can adjust the intensities of the first light L1 and the second light L2 by changing the output power of the light emitting element. For example, a user performs a three-dimensional printing process with a first light L1 of a lower intensity through the three-dimensional printing apparatus 100, and then completes final curing of the three-dimensional object with a second light L2 of a higher intensity through the post-curing apparatus 200.

Referring to fig. 2 again, when the user selects another liquid molding material R2, the light type required for the three-dimensional printing process and the post-curing process is still determined according to the wavelength-absorption relationship of the liquid molding material R2. As can be seen from fig. 2, the intensity of the light is proportional to the absorptance of the liquid molding material, for example, when performing the post-curing process, the second light L2 determines the intensity of the second light L2 according to the absorptance peaks P4, P5 and P6 of the liquid molding material R2, that is, determines the output power of the light emitting elements, for example, the output power of the first light emitting element 231 is set to 100% according to the absorptances shown by the absorptance peaks P4, P5 and P6, the output power of the second light emitting element 232 is set to 90%, and the output power of the third light emitting element 233 is set to 50%.

In addition, when the liquid molding material R1 is compared with the liquid molding material R2, the irradiation time of the second light L2 is inversely proportional to the absorptance of the liquid molding materials R1 and R2, that is, the absorptance of the liquid molding material R2 is substantially half of that of the liquid molding material R1, and therefore the irradiation time required for the liquid molding material R2 is doubled compared with that of the liquid molding material R1.

in summary, in the embodiments of the invention, the three-dimensional printing method determines the light characteristics required for forming and curing the three-dimensional object according to the wavelength-absorption ratio relationship of the liquid molding material, and further adjusts and matches the light with the required characteristics. That is, after the wavelength-absorptance relationship of the liquid molding material is obtained, the number of absorptance peaks corresponding to the wavelength and the corresponding wavelength can be known, so that the molding process of the three-dimensional object can be performed by the first light, wherein the wavelength of the first light is one of the corresponding wavelengths. And then, placing the molded three-dimensional object into a post-curing device, and carrying out a post-curing process on the three-dimensional object by using second light provided by the post-curing device, wherein the second light has corresponding wavelengths comprising the at least two peaks.

In other words, the three-dimensional printing method is to avoid the molding operation of the three-dimensional object with only a single wavelength, that is, the process efficiency of the three-dimensional printing process is considered, the three-dimensional printing device and the post-curing device are matched to adjust the curing means of the three-dimensional object, the three-dimensional object is printed with the light with the single wavelength, and then the post-curing process is performed with the light with multiple wavelengths, so that the three-dimensional object can be completely cured, and the quality of the three-dimensional object is improved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.