A method for filtering and shaping specific light waves based on a non-uniform liquid light medium

Abstract

The application belongs to the technical field of additive manufacturing, and discloses a method for filtering and shaping specific light waves based on a non-uniform liquid light medium. The method comprises the following steps: providing a light curing device, a gas permeable membrane and a printing base plate, the printing base plate and the light curing device being a printing area of a three-dimensional printed part, and the printing area being filled with a non-uniform liquid light medium; providing the light curing device with oxygen-rich gas to form an oxygen-rich light medium layer on the side of the gas permeable membrane away from the light curing device; the specific light waves penetrate through the gas permeable membrane, are filtered and shaped through the oxygen-rich light medium layer, and irradiate the printing area after being filtered and shaped to form a solidification area. The method can quickly shape the specific light waves, so that the specific light waves mainly propagate in a straight way when propagating in the light-cured 3D printing liquid material, the proportion of non-straight light propagation is greatly reduced, and the resolution and accuracy of printing are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a method for filtering and shaping specific light waves based on non-uniform liquid optical media. Background Technology

[0002] Since its inception, 3D printing technology has evolved over several decades into various manufacturing techniques, among which the following are representative: Stereolithography (SLA) using photosensitive resins, Fused Deposition Modeling (FDM) using hot-melt resins, Selective Laser Sintering (SIS) using non-metallic powders, and Selective Laser Melting (SLM) using metallic powders. Of these, Stereolithography is the earliest and most mature technology. Initially using laser galvanometer scanning technology, it has gradually evolved to utilize digital light processing (DLP) and inkjet printing technologies to achieve newer Stereolithography techniques. DLP-based Stereolithography has developed rapidly and attracted widespread attention due to its high precision and low cost.

[0003] Currently, in photopolymer 3D printing, the projected light incident from air onto the non-uniform liquid photosensitive material undergoes reflection, refraction, transmission, diffraction, and scattering, affecting the resolution and printing accuracy of the photopolymerized forming boundary. Furthermore, different photopolymerized materials exhibit varying optical propagation characteristics. For instance, the proportion, particle diameter, and semi-permeability of ceramic particles within the photopolymerized ceramic slurry significantly influence its light propagation properties. Using pre-formed optical wave shaping instruments is insufficient to meet the light wave modulation and shaping requirements of various printing materials.

[0004] Therefore, providing a method for filtering and shaping specific light waves using non-uniform liquid optical media applicable to various printing materials is of significant practical importance for further improving printing accuracy and the resolution of forming boundaries. Summary of the Invention

[0005] The purpose of this invention is to provide a method for filtering and shaping specific light waves based on non-uniform liquid optical media, thereby solving the problems of low boundary resolution and low printing accuracy in existing photopolymerization 3D printing.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for filtering and shaping specific light waves based on a non-uniform liquid optical medium, comprising:

[0008] (1) Provide a photocuring device, a gas permeation membrane and a printing base plate. The printing area between the printing base plate and the photocuring device is the printing area of ​​the three-dimensional printed part. The printing area is filled with a non-uniform liquid photomedia.

[0009] (2) Provide oxygen-rich gas to the photocuring device. The oxygen-rich gas enters the non-uniform liquid photomedia through the gas permeation membrane and forms an oxygen-rich photomedia layer on the side of the gas permeation membrane away from the photocuring device.

[0010] (3) A specific light wave is emitted from the photocuring device and passes through the gas permeation membrane. It is filtered and shaped by the oxygen-rich photodiode layer. The filtered and shaped specific light wave is irradiated onto the printing area to form the curing area.

[0011] Furthermore, in the method for filtering and shaping specific light waves based on non-uniform liquid optical media, the gas permeation membrane in step (1) is a component that is transparent to specific light waves between the photocuring device and the non-uniform liquid optical media.

[0012] Furthermore, in the method for filtering and shaping specific light waves based on non-uniform liquid optical media, the oxygen permeability of the gas permeation membrane in step (1) is >200 barrer.

[0013] Furthermore, in the method for filtering and shaping specific light waves based on non-uniform liquid optical media, the oxygen-rich optical media layer in step (2) is liquid, and the thickness of the oxygen-rich optical media layer is ≤80μm.

[0014] Furthermore, in the method for shaping specific light waves based on non-uniform liquid optical media filtering, the wavelength of the specific light wave in step (3) is 355nm to 2500nm.

[0015] Furthermore, in the method for filtering and shaping specific light waves based on a non-uniform liquid optical medium, the non-uniform liquid optical medium in step (1) is a liquid photosensitive material.

[0016] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) In this invention, a gas permeation membrane is set between the photocuring device and the liquid photosensitive material. The gas permeation membrane is made of polymer material or special coated glass, which allows oxygen-rich gas to quickly pass through the gas permeation membrane into the liquid photosensitive material. A layer of oxygen-rich photosensitive material of a certain thickness is formed on the surface of the gas permeation membrane. Since oxygen will prevent the non-uniform liquid photomedia from being cured by light (i.e., oxygen inhibition effect), the oxygen-rich photosensitive material layer can always maintain the liquid phase and exist between the gas permeation membrane and the deep photosensitive material. When a specific light wave reaches the oxygen-rich photosensitive material layer, the layer will filter and shape the specific light wave, similar to establishing an intrinsic open channel for light. When the specific light wave after passing through the oxygen-rich photosensitive material layer re-enters the same paste (i.e., the curing area), the propagation mode of the light will be mainly direct, while the redundant stray light generated by scattering, refraction, diffraction, etc. will be significantly reduced, thereby significantly improving the printing resolution.

[0018] (2) The present invention uses an oxygen-rich photosensitive material layer to filter and shape specific light waves so that the specific light waves do not change their own properties (such as wavelength and waveform). When the filtered and shaped specific light waves enter the curing area, the shaped specific light waves only reduce the number of photons. The light energy of the reduced photons is converted into the energy required for the curing of the liquid photosensitive material, thereby reducing the loss of light energy and improving the light energy conversion efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0020] Figure 1 This is a schematic diagram of the method of the present invention;

[0021] Figure 2 This is a schematic diagram of the spherical model with a through hole obtained in Example 1;

[0022] Figure 3 This is a schematic diagram of the spherical model with a through hole obtained in Comparative Example 1. Detailed Implementation

[0023] This invention provides a method for filtering and shaping specific light waves based on a non-uniform liquid optical medium, comprising:

[0024] (1) Provide a photocuring device, a gas permeation membrane and a printing base plate. The printing area between the printing base plate and the photocuring device is the printing area of ​​the three-dimensional printed part. The printing area is filled with a non-uniform liquid photomedia.

[0025] (2) Provide oxygen-rich gas to the photocuring device. The oxygen-rich gas enters the non-uniform liquid photomedia through the gas permeation membrane and forms an oxygen-rich photomedia layer on the side of the gas permeation membrane away from the photocuring device.

[0026] (3) A specific light wave is emitted from the photocuring device and passes through the gas permeation membrane. It is filtered and shaped by the oxygen-rich photodiode layer. The filtered and shaped specific light wave is irradiated onto the printing area to form the curing area.

[0027] In this invention, the gas permeation membrane in step (1) is preferably a component that is transparent to a specific light wave between the photocuring device and the non-uniform liquid photomedium.

[0028] In this invention, the oxygen content in the oxygen-enriched gas in step (2) is ≥21%.

[0029] In this invention, the oxygen permeability of the gas permeation membrane in step (1) is preferably >200 barrer, more preferably >500 barrer, and even more preferably >800 barrer.

[0030] In this invention, the oxygen-rich photodiode layer in step (2) is preferably in liquid state.

[0031] In this invention, the thickness of the oxygen-rich photodiode layer in step (2) is preferably ≤80μm, more preferably ≤65μm, and even more preferably ≤45μm.

[0032] In this invention, the wavelength of the specific light wave in step (3) is preferably 355nm to 2500nm. Specific light waves within the above wavelength range can be filtered and shaped using a non-uniform liquid optical medium. Since the specific light wave of commercially available photopolymer printers is mainly 405nm, this invention uses 405nm projection light for testing in a specific embodiment.

[0033] In this invention, the non-uniform liquid optical medium in step (1) is preferably a liquid photosensitive material.

[0034] The present invention does not limit the liquid photosensitive material; any conventional material that can be cured under photoinduction can be selected.

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] This embodiment provides a method for filtering and shaping specific light waves based on a non-uniform liquid optical medium, including:

[0038] Design a spherical model with a through hole, the hole diameter is 450×450μm, and the rod diameter is 300μm;

[0039] (1) Provide a photocuring head, a Teflon gas permeation membrane and a printing base plate. The printing area between the printing base plate and the photocuring head is the printing area of ​​the three-dimensional printed part. The printing area is filled with alumina ceramic printing paste. The alumina ceramic printing paste is a mixture of polyacrylate photocuring resin, diphenyl-(2,4,6-trimethylbenzoyl)oxyphosphorus initiator (TPO), BYK111 dispersant and alumina powder with D50=100nm.

[0040] (2) Provide oxygen-rich gas to the photocuring head. The oxygen enters the alumina ceramic printing paste through a Teflon gas permeation membrane with a permeability of 990 barrer. A liquid oxygen-rich paste layer with a thickness of 1 to 5 μm is formed on the side of the Teflon gas permeation membrane away from the photocuring head.

[0041] (3) DLP projection light with a wavelength of 405nm is emitted from the photocuring head and passes through a Teflon gas permeation membrane. It is then filtered and shaped through a liquid oxygen-rich slurry layer. The filtered and shaped projection light illuminates the printing area, forming a cured area, thus obtaining a spherical model with through-holes, such as... Figure 2 As shown.

[0042] Comparative Example 1

[0043] The difference between this comparative example and Example 1 is that no Teflon gas permeation membrane was used, resulting in a spherical model with through-holes, as shown in Example 1. Figure 3 As shown.

[0044] The results showed that Example 1 ( Figure 2 The spherical model can accurately form a through hole with a diameter of 450×450μm, as shown in Comparative Example 1. Figure 3 The fact that the spherical model could not accurately form the through hole proves that the optical wave shaping method of the present invention significantly improves the resolution and printing accuracy of the photopolymerization forming boundary.

[0045] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for filtering and shaping specific light waves based on a non-uniform liquid optical medium, characterized in that, include: (1) Provide a photocuring device, a gas permeation membrane and a printing base plate. The printing area between the printing base plate and the photocuring device is the printing area of ​​the three-dimensional printed part. The printing area is filled with a non-uniform liquid photomedia. The non-uniform liquid photomedia is alumina ceramic printing paste. (2) Provide oxygen-rich gas to the photocuring device. The oxygen-rich gas enters the non-uniform liquid photomedia through the gas permeation membrane and forms an oxygen-rich photomedia layer on the side of the gas permeation membrane away from the photocuring device. (3) Specific light waves are emitted from the photocuring device and pass through the gas permeation membrane. They are filtered and shaped by the oxygen-rich photodiode layer. The filtered and shaped specific light waves are then irradiated onto the printing area to form a cured area. The gas permeation membrane mentioned in step (1) is a component that is transparent to a specific light wave between the photocuring device and the non-uniform liquid photomedium; The oxygen permeation rate of the gas permeation membrane in step (1) is >200 barrer; The oxygen-rich photodiode layer in step (2) is liquid and the thickness of the oxygen-rich photodiode layer is ≤80μm.

2. The method for filtering and shaping specific light waves based on a non-uniform liquid optical medium according to claim 1, characterized in that, The wavelength of the specific light wave in step (3) is 355nm to 2500nm.

3. The method for filtering and shaping specific light waves based on a non-uniform liquid optical medium according to claim 2, characterized in that, The non-uniform liquid optical medium mentioned in step (1) is a liquid photosensitive material.

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