CN109228315B - Continuous 3D printing system - Google Patents

Abstract

The invention provides a continuous 3D printing system, which comprises a light-transmitting window (1), an uncured layer (2), photosensitive resin (3), a trough (4), optical equipment (5), an object stage (6), a motor (7) and a cured product (8), wherein the light-transmitting window (1) is positioned at the bottom of the trough (4); the photosensitive resin (3) is arranged inside the material groove (4); the photosensitive resin (3) contains titanium dioxide nanoparticles and a component which can be degraded into a polymerization inhibitor by photocatalysis. The invention has the beneficial effects that: an uncured layer is formed on the light-transmitting window in the printing process, so that the mechanical stripping of a cured body and the refilling process of photosensitive resin in the traditional 3D printing can be effectively avoided, and the continuous printing is realized, so that the printing speed is higher than that of the traditional 3D printing by more than 20 times; in the printing process, the thickness of the light-transmitting window is 3-50 mm, and the light-transmitting window is not easy to crack and deform under the action of a drawing force in the printing process, so that the printed product has higher precision, and the printing speed can reach 500 mm/h compared with the latest CLIP technology.

Description

Continuous 3D printing system

Technical Field

The invention relates to a continuous 3D printing system, and belongs to the technical field of printing.

Background

In general, 3D printing is a technique for manufacturing a three-dimensional product by adding materials layer by layer, which is a core technique that integrates leading-edge techniques in many fields and is known as "third industrial revolution". The photocuring 3D printing rapid forming process has the characteristics of low energy consumption, low cost, high forming precision and the like. At present, the traditional photocuring 3D printing technology finally obtains a 3D entity through layer-by-layer superposition, and the method enables the precision of a printed product to be limited by the layering thickness; in addition, conventional SLA and DLP photosensitive resin 3D printing techniques result in long print cycle times due to long photosensitive resin leveling times (top-down printing) or the need for mechanical stripping of the cured layer from the resin tank floor and resin refilling (bottom-up printing).

Recently, Joseph De Si Meng in the United states, in cooperation with his colleagues Alex Ermoskin and Edward Sulmuski, invented a "Continuous meniscus growth" (CLIP) technique, in which the film under the tank of photosensitive resin allows oxygen to pass through but the molecules of photosensitive resin do not, and oxygen enters the photosensitive resin through the film under the tank, and the oxygen inhibition effect of oxygen is utilized during printing, thereby creating a 3D printing process that does not print layer by layer. However, there is no report on a photosensitive resin system specifically used for continuous 3D printing at present.

Disclosure of Invention

In view of the above problems, the technical problem to be solved by the present invention is to provide a continuous 3D printing system.

The technical scheme of the invention is as follows:

a continuous 3D printing system comprises a light-transmitting window (1), an uncured layer (2), photosensitive resin (3), a trough (4), optical equipment (5), an object stage (6), a motor (7) and a cured product (8), wherein the light-transmitting window (1) is positioned at the bottom of the trough (4); the photosensitive resin (3) is arranged inside the material groove (4);

the photosensitive resin (3) contains titanium dioxide nanoparticles and a component which can be degraded into a polymerization inhibitor by photocatalysis;

the non-cured layer forming process is as follows: the optical equipment projects light with two different wavelengths to a light transmission window under the control of a program, because the light with shorter wavelength has weaker penetrating power, titanium dioxide in photosensitive resin closest to the light transmission window absorbs the light with shorter wavelength and then acts with components which can be degraded into a polymerization inhibitor by photocatalysis in the photosensitive resin to generate the polymerization inhibitor and oxygen-containing free radical, the generated polymerization inhibitor and oxygen-containing free radical act with a polymerization reaction active center generated by the photosensitive resin under the action of illumination, so that the reaction active center is quenched or inactivated, the curing reaction is prevented from proceeding, finally an uncured layer is formed between the light transmission window and a cured product, and the photosensitive resin farther from the light transmission window is irradiated by the light with longer wavelength and strong penetrating power to be cured to form the cured product, and the light transmission window is finally characterized in that: the photosensitive resin in contact with the light-transmissive window is not cured, i.e., an uncured layer is formed between the light-transmissive window and the cured article.

The uncured layer can effectively prevent the cured product from being adhered to the light-transmitting window, so that the cured product can be prevented from being peeled from the light-transmitting window and the refilling step of the photosensitive resin in the printing process, the printing time is saved, continuous and rapid printing is finally realized, and the printing speed can reach 500 mm/h.

Preferably, the first and second electrodes are formed of a metal,

the crystal form of the nano titanium dioxide is an anatase structure, and the particle size of the nano titanium dioxide is 1 nm-300 nm;

the photosensitive resin (3) contains a component which can be degraded into a polymerization inhibitor by photocatalysis, and a component which can be degraded into a polymerization inhibitor such as phenols, hindered amines, oxygen and the like.

The component which can be degraded into polymerization inhibitor by photocatalysis in the photosensitive resin (3) comprises at least one component C which can be degraded to generate phenols₁₂-C₃₆Aromatic compounds of ether group.

The photosensitive resin (3) contains components which can be degraded into polymerization inhibitors by photocatalysis, and also comprises compounds which can be decomposed to generate oxygen, such as hydrogen peroxide, calcium peroxide, sodium peroxycarbonate and the like.

In a continuous 3D printing system, the light source employed by the optical device (5) is two light sources of different wavelengths. A light source with wavelength less than 400 nm is mainly used for exciting titanium dioxide in photosensitive resin to generate polymerization inhibitor and oxygen-containing free radical in the photosensitive resin to inhibit the curing reaction; the wavelength of the other light source is greater than 400 nm and is mainly responsible for exciting a photoinitiator in the photosensitive resin to cure the photosensitive resin, and the thickness of the uncured layer is regulated and controlled by regulating the intensity of the two light sources.

In the present invention, the "component which can be photocatalytically degraded into a polymerization inhibitor" is a compound component which can be degraded to produce polymerization inhibitors such as phenols, oxygen, and the like.

The technical problems solved by the invention are as follows:

1. compared with the traditional 3D printing of photosensitive resin, the traditional printing is intermittent printing which needs the stripping of a cured layer and the refilling of the photosensitive resin, and the printing time is long; and our not solidification layer can effectively avoid solidification goods and printing opacity window adhesion, consequently, in the printing process, can avoid solidifying the peeling off of goods in the step of refilling of printing opacity window and photosensitive resin to practice thrift the printing time, finally realize continuous quick printing, solved traditional 3D and printed the problem that intermittent printing, speed are slow.

2. Compared with the CLIP technology, the CLIP technology control method needs to use a film (oxygen permeable film) which can allow oxygen to pass through, the thickness of the film is about 0.1 mm, the film is easy to wear and break, meanwhile, the oxygen permeable film is bent and deformed under the action of a drawing die force in the printing process, the deformation and the deformation shape cannot be controlled, and therefore, the printing precision is low. The continuous 3D printing system realizes that the thickness of a printing light-transmitting window can reach several millimeters, and the printing window is not easy to crack and deform under the action of a drawing force in the printing process, so that the printed product has higher precision, and the problems of high printing speed and low precision of the CLIP technology are solved.

The invention has the following beneficial effects:

an uncured layer is formed at the contact interface of the light-transmitting window and the photosensitive resin in the printing process, so that the mechanical stripping of a cured body and the refilling process of the photosensitive resin in the traditional 3D printing can be effectively avoided, and the continuous printing is realized, so that the printing speed is higher than that of the traditional 3D printing by the photosensitive resin and is 20-100 times higher than that of the traditional 3D printing;

compared with the CLIP technology, the thickness of the light-transmitting window is 3-50 mm in the printing process of the continuous 3D printing system, and the continuous 3D printing system is not easy to crack and deform under the action of a drawing force in the printing process, so that the printed product has higher precision, and the printing speed can reach 500 mm/h compared with the latest CLIP technology;

when the invention adopts two light sources, the thickness of the uncured layer (2) is regulated and controlled by adjusting the intensity of the two light sources, so that the control of the die drawing force in the continuous printing process is realized, and the printing process is more controllable.

In conclusion, the invention realizes high printing speed and simultaneously improves the printing precision.

Drawings

For ease of illustration, the invention is described in detail by the following detailed description and the accompanying drawings.

Fig. 1 is a schematic structural diagram of a 3D printing system according to the present invention.

Wherein, 1 is the light-transmitting window, 2 is not solidified layer, 3 is photosensitive resin, 4 is the silo, 5 is optical equipment, 6 is the objective table, 7 is the motor, 8 is the solidification goods.

Detailed Description

Example 1

As shown in fig. 1, the continuous 3D printing system of the present embodiment includes a light-transmissive window (1), an uncured layer (2), a photosensitive resin (3), a trough (4), an optical device (5), a stage (6), a motor (7), and a cured product (8), wherein the light-transmissive window (1) is located at the bottom of the trough (4); the photosensitive resin (3) is arranged inside the material groove (4);

the photosensitive resin (3) contains titanium dioxide nanoparticles and a component which can be degraded into a polymerization inhibitor by photocatalysis;

the photosensitive resin (3) contains nano titanium dioxide particles with the particle size of 1 nm; the crystal form of the nano titanium dioxide is an anatase structure.

The component which can be degraded into polymerization inhibitor by photocatalysis in the photosensitive resin (3) is quinone hydroquinone;

the non-cured layer forming process is as follows: the optical device (5) projects light to the light transmission window under the control of a program, because the light with shorter wavelength has weaker penetrating power, the titanium dioxide in the photosensitive resin (3) closest to the light transmission window (5) absorbs the light with shorter wavelength and then reacts with the components which can be degraded into polymerization inhibitor by photocatalysis in the photosensitive resin (3) to generate the polymerization inhibitor and oxygen-containing free radical, the generated polymerization inhibitor and the oxygen-containing free radical react with the polymerization reaction active center generated by the light irradiation of the photosensitive resin (3), thereby quenching or deactivating the reactive centers and preventing the curing reaction from proceeding, and finally forming an uncured layer between the light transmission window (1) and the cured article (8), and the photosensitive resin far away from the light-transmitting window (1) is irradiated by light with strong penetrating power and longer wavelength to be cured to form a cured product (8), and the curing is finally shown as follows: the photosensitive resin in contact with the light transmissive window (1) is uncured, i.e., an uncured layer is formed between the light transmissive window (1) and the cured article (8).

In a continuous printing mode, an image projected by the optical equipment (5) under the control of a program is an image played by continuous animation, a section image of a digital model output by the program is a continuously-changed video image, the motor (7) is matched to continuously operate to drive the objective table (6) to continuously move upwards, and meanwhile, the photosensitive resin (3) is continuously supplemented to a curing area, so that continuous printing is realized, and a complete cured product (8) is finally obtained; in the intermittent printing mode, namely after the cured product (8) is stuck on the objective table (6) and moves upwards for one layer thickness, the photosensitive resin (3) is refilled, then the optical device (5) projects a pattern of the corresponding layer to enable the photosensitive resin (3) to be cured continuously, and the steps are repeated, so that the complete cured product (8) is obtained finally.

One of the light sources used by the optical device (5) has a wavelength of 365 nm; the other wavelength is 405 nm.

The printing speed can reach 400 mm/h, and the printing precision can reach 0.01 mm.

Example 2

As shown in fig. 1, the continuous 3D printing system of the present embodiment includes a light-transmissive window (1), an uncured layer (2), a photosensitive resin (3), a trough (4), an optical device (5), a stage (6), a motor (7), and a cured product (8), wherein the light-transmissive window (1) is located at the bottom of the trough (4); the photosensitive resin (3) is arranged inside the material groove (4);

the photosensitive resin (3) contains titanium dioxide nanoparticles and a component which can be degraded into a polymerization inhibitor by photocatalysis;

the photosensitive resin (3) contains nano titanium dioxide particles with the particle size of 300 nm; the crystal form of the nano titanium dioxide is an anatase structure.

The component which can be degraded into polymerization inhibitor by photocatalysis in the photosensitive resin (3) is bis (2-diphenylphosphinophenyl) ether;

the non-cured layer forming process is as follows: the optical device (5) projects light to the light transmission window under the control of a program, because the light with shorter wavelength has weaker penetrating power, the titanium dioxide in the photosensitive resin (3) closest to the light transmission window (5) absorbs the light with shorter wavelength and then reacts with the components which can be degraded into polymerization inhibitor by photocatalysis in the photosensitive resin (3) to generate the polymerization inhibitor and oxygen-containing free radical, the generated polymerization inhibitor and the oxygen-containing free radical react with the polymerization reaction active center generated by the light irradiation of the photosensitive resin (3), thereby quenching or deactivating the reactive centers and preventing the curing reaction from proceeding, and finally forming an uncured layer between the light transmission window (1) and the cured article (8), and the photosensitive resin far away from the light-transmitting window (1) is irradiated by light with strong penetrating power and longer wavelength to be cured to form a cured product (8), and the curing is finally shown as follows: the photosensitive resin in contact with the light transmissive window (1) is uncured, i.e., an uncured layer is formed between the light transmissive window (1) and the cured article (8).

In a continuous printing mode, an image projected by the optical equipment (5) under the control of a program is an image played by continuous animation, a section image of a digital model output by the program is a continuously-changed video image, the motor (7) is matched to continuously operate to drive the objective table (6) to continuously move upwards, and meanwhile, the photosensitive resin (3) is continuously supplemented to a curing area, so that continuous printing is realized, and a complete cured product (8) is finally obtained; in the intermittent printing mode, namely after the cured product (8) is stuck on the objective table (6) and moves upwards for one layer thickness, the photosensitive resin (3) is refilled, then the optical device (5) projects a pattern of the corresponding layer to enable the photosensitive resin (3) to be cured continuously, and the steps are repeated, so that the complete cured product (8) is obtained finally.

One of the wavelengths of the light sources used by the optical device (5) is 266 nm; the other wavelength is 405 nm.

The printing speed can reach 450 mm/h, and the printing precision can reach 0.01 mm.

Example 3

As shown in fig. 1, the continuous 3D printing system of the present embodiment includes a light-transmissive window (1), an uncured layer (2), a photosensitive resin (3), a trough (4), an optical device (5), a stage (6), a motor (7), and a cured product (8), wherein the light-transmissive window (1) is located at the bottom of the trough (4); the photosensitive resin (3) is arranged inside the material groove (4);

the photosensitive resin (3) contains titanium dioxide nanoparticles and a component which can be degraded into a polymerization inhibitor by photocatalysis;

the photosensitive resin (3) contains nano titanium dioxide particles with the particle size of 30 nm; the crystal form of the nano titanium dioxide is an anatase structure.

The components which can be degraded into polymerization inhibitor by photocatalysis in the photosensitive resin (3) are quinone hydroquinone and hydrogen peroxide, and the molar ratio is 4: 1;

the non-cured layer forming process is as follows: the optical device (5) projects light to the light transmission window under the control of a program, because the light with shorter wavelength has weaker penetrating power, the titanium dioxide in the photosensitive resin (3) closest to the light transmission window (5) absorbs the light with shorter wavelength and then reacts with the components which can be degraded into polymerization inhibitor by photocatalysis in the photosensitive resin (3) to generate the polymerization inhibitor and oxygen-containing free radical, the generated polymerization inhibitor and the oxygen-containing free radical react with the polymerization reaction active center generated by the light irradiation of the photosensitive resin (3), thereby quenching or deactivating the reactive centers and preventing the curing reaction from proceeding, and finally forming an uncured layer between the light transmission window (1) and the cured article (8), and the photosensitive resin far away from the light-transmitting window (1) is irradiated by light with strong penetrating power and longer wavelength to be cured to form a cured product (8), and the curing is finally shown as follows: the photosensitive resin in contact with the light transmissive window (1) is uncured, i.e., an uncured layer is formed between the light transmissive window (1) and the cured article (8).

In a continuous printing mode, an image projected by the optical equipment (5) under the control of a program is an image played by continuous animation, a section image of a digital model output by the program is a continuously-changed video image, the motor (7) is matched to continuously operate to drive the objective table (6) to continuously move upwards, and meanwhile, the photosensitive resin (3) is continuously supplemented to a curing area, so that continuous printing is realized, and a complete cured product (8) is finally obtained; in the intermittent printing mode, namely after the cured product (8) is stuck on the objective table (6) and moves upwards for one layer thickness, the photosensitive resin (3) is refilled, then the optical device (5) projects a pattern of the corresponding layer to enable the photosensitive resin (3) to be cured continuously, and the steps are repeated, so that the complete cured product (8) is obtained finally.

One of the wavelengths of the light sources used by the optical device (5) is 266 nm; the other wavelength is 405 nm.

The printing speed can reach 500 mm/h, and the printing precision can reach 0.01 mm.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (4)

1. The continuous 3D printing system is characterized by comprising a light-transmitting window (1), an uncured layer (2), photosensitive resin (3), a trough (4), optical equipment (5), an object stage (6), a motor (7) and a cured product (8), wherein the light-transmitting window (1) is positioned at the bottom of the trough (4); the photosensitive resin (3) is arranged inside the material groove (4);

the photosensitive resin (3) contains titanium dioxide nanoparticles and a component which can be degraded into a polymerization inhibitor by photocatalysis;

the forming process of the uncured layer (2) is as follows: the optical device (5) projects light to the light transmission window under the control of a program, because the light with shorter wavelength has weaker penetrating power, the titanium dioxide in the photosensitive resin (3) closest to the light transmission window (5) absorbs the light with shorter wavelength and then reacts with the components which can be degraded into polymerization inhibitor by photocatalysis in the photosensitive resin (3) to generate the polymerization inhibitor and oxygen-containing free radical, the generated polymerization inhibitor and oxygen-containing free radical react with the polymerization reaction active center generated by the light irradiation of the photosensitive resin (3), thereby quenching or deactivating the reactive centers and preventing the curing reaction from proceeding, and finally forming an uncured layer between the light transmission window (1) and the cured article (8), and the photosensitive resin far away from the light-transmitting window (1) is irradiated by light with strong penetrating power and longer wavelength to be cured to form a cured product (8), and the curing is finally shown as follows: the photosensitive resin in contact with the light-transmissive window (1) is not cured, i.e. an uncured layer is formed between the light-transmissive window (1) and the cured article (8);

the crystal form of the nano titanium dioxide is an anatase structure, and the particle size of the nano titanium dioxide is 1 nm-300 nm;

the optical device (5) is provided with two light sources which can be independently controlled, wherein the wavelength of one light source is less than 400 nm, titanium dioxide can absorb and be excited, electrons in a valence band can obtain the energy of photons and jump to a conduction band, and a polymerization inhibitor is generated in photosensitive resin; the other light source with wavelength larger than 400 nm can decompose the photoinitiator to initiate polymerization reaction.

2. The continuous 3D printing system according to claim 1, wherein the component of the photosensitive resin (3) that can be photocatalytically degraded into a polymerization inhibitor is a component of a compound that can be degraded to produce phenols, hindered amines or oxygen.

3. The continuous 3D printing system according to claim 1, wherein the component of the photosensitive resin (3) containing a polymerization inhibitor that can be photocatalytically degraded comprises at least one C containing a phenol that can be degraded to generate phenol₁₂-C₃₆Aromatic compounds of ether group.

4. The continuous 3D printing system according to claim 2, wherein the photosensitive resin (3) contains a component that can be photocatalytically degraded into a polymerization inhibitor, and further comprises hydrogen peroxide, calcium peroxide or sodium percarbonate.

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