Slit coating slot die head for improved coating efficiency and reduced air bubble entrapment

Abstract

The present invention discloses a slit coating slot die head for improving coating efficiency and reducing bubble entrainment. The die head includes a first coating module, a second coating module, a downstream gasket, an upstream gasket, a central gasket, an upstream guide vane, and a downstream guide vane. The first coating module, the upstream gasket, the central gasket, the downstream gasket, and the second coating module are fixed together from left to right, with the upper part of the upstream guide vane fixedly connected to the lower part of the upstream gasket, and the upper part of the downstream guide vane fixedly connected to the lower part of the downstream gasket. According to the present invention, during coating, the upstream guide vane and the downstream guide vane stabilize the upstream meniscus without disrupting the overall flow, and break down vortices that form at the contact surface between the upstream meniscus and the substrate, reducing bubble entrainment, ensuring thin film surface quality, and achieving stable and effective coating. The surfaces of the upstream guide vane and the downstream guide vane of the present invention are formed with an array of small grooves, which ensures flow stability and further improves production efficiency.

Description

[Technical Field]

[0001] The present invention relates to the technical field of coating machines, and more particularly to a slit coating slot die head and method of use for improving coating efficiency and reducing air bubble entrapment. [Background technology]

[0002] Slit coating technology plays a vital role in thin film manufacturing and has broad application prospects, especially in high-precision coating applications. This technology precisely controls the speed and width of the coating solution flowing through the slit, enabling coating uniformity and controllability, thereby ensuring high-precision thin film thickness uniformity during the manufacturing process. This technology is particularly suitable for fields with stringent coating requirements, such as the electronics, optics, and energy industries, and can achieve uniform coating on a variety of complex surfaces, including curved and flexible substrates. Furthermore, with the continuous development of advanced manufacturing technologies, slit coating technology has important application value in the large-scale production of novel materials, such as functional thin films, optical films, and electronic thin films. The control of thin film structure, performance, and quality uniformity achieved by this technology provides technical support for the innovation and commercialization of high-performance materials. Therefore, research and development of slit coating technology is key to achieving high-end manufacturing and high-performance products.

[0003] However, conventional slit coating technology suffers from the problem of air bubble entrapment in practical applications, which is a significant factor limiting coating efficiency and product quality. During the slit coating process, when the liquid coating passes through the slit and comes into contact with the substrate, air bubbles are likely to form due to factors such as the fluidity and interfacial tension of the coating liquid. These air bubbles are then entrained in the coating, resulting in the formation of bubbles on the coating surface. The presence of air bubbles can affect not only the uniformity and smoothness of the thin film but also the functionality of the final product. In particular, in fields requiring high precision, such as electronics and optics, the occurrence of air bubbles can lead to performance degradation. At the same time, the problem of air bubble entrapment often limits production efficiency during the coating process. To avoid air bubble formation and entrapment, additional control and treatment are required during the production process, such as slowing down the coating speed, optimizing the fluidity of the coating liquid, and improving the surface tension of the substrate. While these measures are effective, they often result in extended production cycles and increased costs.

[0004] Therefore, designing a slit coating slot die head that can effectively solve the problem of air bubble entrapment and improve the stability and efficiency of the coating process has become an important issue that must be resolved urgently in the thin film coating industry. To meet the urgent need for high-performance thin film coating processes in the industry, the structure of the coating equipment must not only ensure improved coating uniformity and interface stability, but also precisely adjust and control various liquids. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above technical problems, and provides a slit coating slot die head that can effectively solve the problem of air bubble entrapment, improves coating efficiency, and reduces air bubble entrapment, thereby improving stability and efficiency in the coating process. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention employs the following technical means. One aspect of the present invention is a slit coating slot die head for improving coating efficiency and reducing air bubble entrainment, comprising a first coating module, a second coating module, a downstream gasket, an upstream gasket, a central gasket, an upstream guide vane, and a downstream guide vane, wherein the first coating module, the upstream gasket, the central gasket, the downstream gasket, and the second coating module are fixed together in this order from left to right, and an upper portion of the upstream guide vane and a lower portion of the upstream gasket are fixedly connected, and an upper portion of the downstream guide vane and a lower portion of the downstream gasket are fixedly connected, An arc-shaped manifold is opened on the inner wall of the first coating module, and an inclined flow path is connected to the lower part of the manifold; an inverted U-shaped groove is provided in the upstream gasket, and the shape of the inverted U-shaped groove is configured to match the shape of the top end of the manifold of the first coating module, and the width of the inverted U-shaped groove is configured to match the width of an inclined flow path connected to a lower part of the manifold of the first coating module; a liquid supply port is opened in an outer wall of the second coating module; an arc-shaped manifold is formed on an inner wall of the second coating module, and an inclined flow path is connected to the lower part of the manifold, and the manifold and the liquid supply port are in communication with each other; the downstream gasket is provided with an inverted U-shaped groove, and the shape of the tip of the inverted U-shaped groove is configured to match the shape of the upper end of the manifold of the second coating module, and the width of the inverted U-shaped groove is configured to match the width of an inclined flow path connected to a lower part of the manifold of the second coating module; An inverted U-shaped groove is provided at the bottom end of the central gasket, and the shape of the tip of the inverted U-shaped groove is configured to match the shape of the upper end of the manifold of the first application module, and the width of the inverted U-shaped groove is configured to match the width of the inclined flow path connected below the manifold of the first application module.

[0007] Furthermore, the upstream gasket has rectangular grooves on both the front and rear sides of its bottom end, the upstream guide vane has a rectangular connecting plate, an arc-shaped plate, and a horizontal plate, there are two rectangular connecting plates, each fixedly connected to both the front and rear sides of the upper edge of the arc-shaped plate, the lower edge of the arc-shaped plate is fixedly connected to the horizontal plate, the width d2 of the rectangular connecting plate is the same as the width d1 of the rectangular groove provided at the bottom end of the upstream gasket, and the length h2 of the rectangular connecting plate is greater than the length h1 of the rectangular groove provided at the bottom end of the upstream gasket, The downstream gasket has rectangular grooves on both the front and rear sides of its bottom end, and the downstream guide vane has a rectangular connecting plate, an arc-shaped plate, and a horizontal plate. There are two rectangular connecting plates, which are fixedly connected to both the front and rear sides of the upper edge of the arc-shaped plate, and the lower edge of the arc-shaped plate is fixedly connected to the horizontal plate. The rectangular connecting plate has a width d4 that is equal to the width d3 of the rectangular groove provided at the bottom end of the downstream gasket and a length h4 that is greater than the length h3 of the rectangular groove provided at the bottom end of the downstream gasket.

[0008] Furthermore, the first application module, the upstream gasket, the central gasket, the downstream gasket and the second application module are fixedly connected in sequence by bolts.

[0009] Furthermore, the thickness w2 of the upstream guide vane is greater than the thickness w1 of the upstream gasket, and the upstream guide vane and the upstream gasket are fastened together by frictional force during the installation process using an interference fit; the thickness w4 of the downstream guide vane is greater than the thickness w3 of the downstream gasket, and the downstream guide vane and the downstream gasket are fastened together by frictional force during the installation process using an interference fit.

[0010] Furthermore, the size of the upstream guide vane is selected according to the properties of the coating liquid and the substrate to be coated, and the size of the downstream guide vane is selected according to the properties of the coating liquid and the substrate to be coated.

[0011] Furthermore, small grooves measuring in millimeters are formed on the surface of the upstream guide vane, with the aspect ratio of the array being 1:2, and small grooves arranged in an array are formed on the surface of the downstream guide vane. [Effects of the Invention]

[0012] The present invention has the following advantages over the prior art. 1. In accordance with the present invention, during coating, the upstream guide vane and downstream guide vane stabilize the upstream meniscus without disrupting the overall flow, and disrupt the vortex generated at the contact surface between the upstream meniscus and the substrate, reducing the entrainment of air bubbles, thereby ensuring the quality of the thin film surface and achieving stable and effective coating.

[0013] 2. The surfaces of the upstream guide vane and downstream guide vane of the present invention are formed with an array of small grooves, which ensures flow stability and further improves manufacturing efficiency.

[0014] 3. The horizontal plates at the bottom of the upstream and downstream guide vanes of this invention allow the head height to be controlled equally, dividing the downstream coating process into multiple coating processes with lower head heights, contributing to flow stability. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram (assembly diagram) showing the overall configuration of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing a cross section of FIG. [Figure 3] 1 is a schematic diagram showing an array of small grooves on the surface of an upstream guide vane and a downstream guide vane; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will now be further described with reference to the drawings. As shown in Figures 1 to 3, a slit coating slot die head for improving coating efficiency and reducing air bubble entrainment includes a first coating module 1, a second coating module 2, a downstream gasket 3, an upstream gasket 4, a central gasket 5, an upstream guide vane 6, and a downstream guide vane 7, and the first coating module 1, the upstream gasket 4, the central gasket 5, the downstream gasket 3, and the second coating module 2 are fixed together in this order from left to right, and the upper part of the upstream guide vane 6 and the lower part of the upstream gasket 4 are fixedly connected, and the upper part of the downstream guide vane 7 and the lower part of the downstream gasket 3 are fixedly connected, An arc-shaped manifold is opened on the inner wall of the first coating module 1, and an inclined flow path is connected to the lower part of the manifold. the upstream gasket (4) is provided with an inverted U-shaped groove, and the shape of the tip of the inverted U-shaped groove is configured to match the shape of the upper end of the manifold of the first coating module (1), and the width of the inverted U-shaped groove is configured to match the width of the inclined flow path connected to the lower part of the manifold of the first coating module (1); A liquid supply port is opened in the outer wall of the second coating module 2, An arc-shaped manifold is formed on the inner wall of the second coating module 2, and an inclined flow path is connected to the lower part of the manifold, and the manifold and the liquid supply port are connected to each other. the downstream gasket (3) is provided with an inverted U-shaped groove, and the shape of the tip of the inverted U-shaped groove is configured to match the shape of the upper end of the manifold of the second coating module (2), and the width of the inverted U-shaped groove is configured to match the width of the inclined flow path connected to the lower part of the manifold of the second coating module (2); An inverted U-shaped groove is provided at the bottom end of the central gasket 5, and the shape of the tip of the inverted U-shaped groove is configured to match the shape of the upper end of the manifold of the first application module 1, and its width is configured to match the width of the inclined flow path connected below the manifold of the first application module 1.

[0017] Furthermore, the upstream gasket 4 has rectangular grooves on both the front and rear sides of its bottom end, the upstream guide vane 6 has a rectangular connecting plate, an arc-shaped plate, and a horizontal plate, there are two rectangular connecting plates, each fixedly connected to the front and rear sides of the upper edge of the arc-shaped plate, the lower edge of the arc-shaped plate fixedly connected to the horizontal plate, the width d2 of the rectangular connecting plate is the same as the width d1 of the rectangular groove provided at the bottom end of the upstream gasket 4, and the length h2 of the rectangular connecting plate is greater than the length h1 of the rectangular groove provided at the bottom end of the upstream gasket 4,

[0018] The downstream gasket 3 has rectangular grooves on both the front and rear sides of its bottom end, and the downstream guide vane 7 has a rectangular connecting plate, an arc-shaped plate, and a horizontal plate. There are two rectangular connecting plates, which are fixedly connected to both the front and rear sides of the upper edge of the arc-shaped plate, and the lower edge of the arc-shaped plate is fixedly connected to the horizontal plate. The rectangular connecting plate is configured so that its width d4 is the same as the width d3 of the rectangular groove provided at the bottom end of the downstream gasket 3 and its length h4 is greater than the length h3 of the rectangular groove provided at the bottom end of the downstream gasket 3.

[0019] Furthermore, the first coating module 1, the upstream gasket 4, the central gasket 5, the downstream gasket 3 and the second coating module 2 are fixedly connected in sequence by bolts.

[0020] Furthermore, the thickness w2 of the upstream guide vane 6 is greater than the thickness w1 of the upstream gasket 4, and the upstream guide vane 6 and the upstream gasket 4 are fastened together by frictional force during the installation process using an interference fit; the thickness w4 of the downstream guide vane 7 is greater than the thickness w3 of the downstream gasket 3, and the downstream guide vane 7 and the downstream gasket 3 are fastened together by frictional force during the installation process using an interference fit.

[0021] Furthermore, the size of the upstream guide vane 6 is selected according to the properties of the coating liquid and the substrate to be coated, and the size of the downstream guide vane 7 is selected according to the properties of the coating liquid and the substrate to be coated.

[0022] Furthermore, small grooves measuring in millimeters are formed on the surface of the upstream guide vane 6, with the aspect ratio of the array being 1:2, and small grooves arranged in an array are formed on the surface of the downstream guide vane 7.

[0023] The present invention follows the steps below to adjust the guide vanes according to the coating material and process.

[0024] First, appropriate upstream guide vanes 6 and downstream guide vanes 7 are selected according to the coating process, substrate wettability, and materials used, and the selected upstream guide vanes 6 and downstream guide vanes 7 are inserted into the rectangular grooves on the left and right sides of the bottom end of the upstream gasket 4 and the rectangular grooves on the left and right sides of the bottom end of the downstream gasket 3, respectively. Then, the first coating module 1, upstream gasket 4, central gasket 5, downstream gasket 3, and second coating module 2 are fastened together with bolts, and the upstream guide vanes 6 and downstream guide vanes 7 are fastened together using an interference fit.

[0025] The optical liquid adhesive required for coating flows from a liquid supply port on the outer wall of the second coating module 2 into an arc-shaped manifold on the inner wall of the first coating module 1 and an arc-shaped manifold on the inner wall of the second coating module 2, then into a flow path below the manifolds, and then through slits formed by the upstream gasket 4, the center gasket 5, and the downstream gasket 3 into the upstream guide vane 6 and the downstream guide vane 7. As the fluid flows through the upstream guide vane 6 and the downstream guide vane 7, the presence of an array of small grooves on the surfaces of the upstream guide vane 6 and the downstream guide vane 7 ensures flow stability. Research has also shown that air bubble entrainment is mainly caused by vortices generated at the contact surface between the upstream meniscus and the substrate. The upstream guide vane 6 and the downstream guide vane 7 can disrupt the vortex without changing the overall flow direction, reducing air bubble entrainment, thereby improving the coating speed and ensuring the surface quality of the thin film.

[0026] As described above, a person having ordinary knowledge in the relevant technical field can make various other modifications and variations based on the technical means and technical ideas of the present invention, and all of these modifications and variations fall within the scope of protection of the claims.

[0027] (Addendum) (Appendix 1) The system comprises a first coating module (1), a second coating module (2), a downstream gasket (3), an upstream gasket (4), a central gasket (5), an upstream guide vane (6), and a downstream guide vane (7), wherein the first coating module (1), the upstream gasket (4), the central gasket (5), the downstream gasket (3), and the second coating module (2) are fixed together in this order from left to right, and an upper portion of the upstream guide vane (6) and a lower portion of the upstream gasket (4) are fixedly connected, and an upper portion of the downstream guide vane (7) and a lower portion of the downstream gasket (3) are fixedly connected, An arc-shaped manifold is opened on the inner wall of the first coating module (1), and an inclined flow path is connected to the lower part of the manifold. the upstream gasket (4) is provided with an inverted U-shaped groove, and the shape of the tip of the inverted U-shaped groove is configured to match the shape of the upper end of the manifold of the first coating module (1), and the width of the inverted U-shaped groove is configured to match the width of an inclined flow path connected to a lower part of the manifold of the first coating module (1); A liquid supply port is opened on the outer wall of the second coating module (2), An arc-shaped manifold is formed on the inner wall of the second coating module (2), and an inclined flow path is connected to the lower part of the manifold, and the manifold and a liquid supply port are in communication with each other. the downstream gasket (3) is provided with an inverted U-shaped groove, and the shape of the tip of the inverted U-shaped groove is configured to match the shape of the upper end of the manifold of the second coating module (2), and the width of the inverted U-shaped groove is configured to match the width of the inclined flow path connected to the lower part of the manifold of the second coating module (2); an inverted U-shaped groove is provided at the bottom end of the central gasket (5), and the shape of the tip of the inverted U-shaped groove matches the shape of the upper end of the manifold of the first application module (1), and the width of the inverted U-shaped groove matches the width of the inclined flow channel connected to the lower part of the manifold of the first application module (1); The upstream gasket (4) has rectangular grooves on both the front and rear sides of its bottom end, the upstream guide vane (6) has a rectangular connecting plate, an arc-shaped plate, and a horizontal plate, there are two rectangular connecting plates, each fixedly connected to both the front and rear sides of the upper edge of the arc-shaped plate, the lower edge of the arc-shaped plate is fixedly connected to the horizontal plate, the width d2 of the rectangular connecting plate is the same as the width d1 of the rectangular groove provided at the bottom end of the upstream gasket (4), and the length h2 of the rectangular connecting plate is greater than the length h1 of the rectangular groove provided at the bottom end of the upstream gasket (4), a width d4 of the rectangular connecting plate that matches the width d3 of the rectangular groove provided at the bottom end of the downstream gasket (3) and that is greater than the length h3 of the rectangular groove provided at the bottom end of the downstream gasket (3).

[0028] (Appendix 2) The slit coating slot die head for improving coating efficiency and reducing air bubble entrainment described in Appendix 1, characterized in that the first coating module (1), the upstream gasket (4), the central gasket (5), the downstream gasket (3) and the second coating module (2) are fixedly connected in sequence by bolts.

[0029] (Appendix 3) The slit coating slot die head for improving coating efficiency and reducing air bubble entrainment described in Appendix 1 is characterized in that the thickness w2 of the upstream guide vane (6) is greater than the thickness w1 of the upstream gasket (4) and is fastened by frictional force during the installation process using an interference fit, and the thickness w4 of the downstream guide vane (7) is greater than the thickness w3 of the downstream gasket (3) and is fastened by frictional force during the installation process using an interference fit.

[0030] (Appendix 4) The slit coating slot die head for improving coating efficiency and reducing air bubble entrainment described in Appendix 1, wherein the size of the upstream guide vane (6) is selected according to the properties of the coating liquid and the substrate to be coated, and the size of the downstream guide vane (7) is selected according to the properties of the coating liquid and the substrate to be coated.

[0031] (Appendix 5) The slit coating slot die head for improving coating efficiency and reducing air bubble entrainment described in Appendix 1 is characterized in that small grooves on the order of millimeters are formed on the surface of the upstream guide vane (6) so that the aspect ratio of the array is 1:2, and small grooves in an array are formed on the surface of the downstream guide vane (7). [Explanation of symbols]

[0032] 1: first application module; 2: second application module; 3: downstream gasket, 4: Upstream gasket, 5: Central gasket, 6: Upstream guide vane, 7: Downstream guide vane.

Claims

1. The apparatus comprises a first coating module (1), a second coating module (2), a downstream gasket (3), an upstream gasket (4), a central gasket (5), an upstream guide vane (6), and a downstream guide vane (7), wherein the first coating module (1), the upstream gasket (4), the central gasket (5), the downstream gasket (3), and the second coating module (2) are fixed together in this order from left to right, and the upper part of the upstream guide vane (6) and the lower part of the upstream gasket (4) are fixedly connected, and the upper part of the downstream guide vane (7) and the lower part of the downstream gasket (3) are fixedly connected, An arc-shaped manifold is opened on the inner wall of the first coating module (1), and an inclined flow path is connected to the lower part of the manifold; the upstream gasket (4) is provided with an inverted U-shaped groove, the shape of the tip of the inverted U-shaped groove being configured to match the shape of the upper end of the manifold of the first coating module (1), and the width of the inverted U-shaped groove being configured to match the width of the inclined flow path connected to the lower part of the manifold of the first coating module (1); A liquid supply port is opened on the outer wall of the second coating module (2), An arc-shaped manifold is opened on the inner wall of the second coating module (2), and an inclined flow path is connected to the lower part of the manifold, and the manifold and the liquid supply port are in communication with each other. the downstream gasket (3) is provided with an inverted U-shaped groove, and the shape of the tip of the inverted U-shaped groove is configured to match the shape of the upper end of the manifold of the second coating module (2), and the width of the inverted U-shaped groove is configured to match the width of an inclined flow path connected to a lower part of the manifold of the second coating module (2); an inverted U-shaped groove is provided at the bottom end of the central gasket (5), and the shape of the tip of the inverted U-shaped groove matches the shape of the upper end of the manifold of the first application module (1), and the width of the inverted U-shaped groove is configured to match the width of the inclined flow channel connected to the lower part of the manifold of the first application module (1); The upstream gasket (4) has rectangular grooves on both the front and rear sides of its bottom end, and the upstream guide vane (6) includes a rectangular connecting plate, an arc-shaped plate, and a horizontal plate. There are two rectangular connecting plates, each fixedly connected to both the front and rear sides of the upper edge of the arc-shaped plate, and the lower edge of the arc-shaped plate is fixedly connected to the horizontal plate. The rectangular connecting plate has a width d2 that is equal to the width d1 of the rectangular groove provided at the bottom end of the upstream gasket (4) and a length h2 that is greater than the length h1 of the rectangular groove provided at the bottom end of the upstream gasket (4). a width d4 of the rectangular connecting plate that matches the width d3 of the rectangular groove provided at the bottom end of the downstream gasket (3) and that is greater than the length h3 of the rectangular groove provided at the bottom end of the downstream gasket (3).

2. 2. The slit coating slot die head for improving coating efficiency and reducing air bubble entrapment according to claim 1, wherein the first coating module (1), the upstream gasket (4), the central gasket (5), the downstream gasket (3) and the second coating module (2) are fixedly connected in sequence by bolts.

3. 2. The slit coating slot die head for improving coating efficiency and reducing air bubble entrainment as claimed in claim 1, wherein the thickness w2 of the upstream guide vane (6) is greater than the thickness w1 of the upstream gasket (4) and is fastened by frictional force during the installation process using an interference fit, and the thickness w4 of the downstream guide vane (7) is greater than the thickness w3 of the downstream gasket (3) and is fastened by frictional force during the installation process using an interference fit.

4. 2. A slit coating slot die head for improving coating efficiency and reducing air bubble entrainment according to claim 1, wherein the size of the upstream guide vane (6) is selected according to the properties of the coating liquid and the substrate to be coated, and the size of the downstream guide vane (7) is selected according to the properties of the coating liquid and the substrate to be coated.

5. 2. A slit coating slot die head for improving coating efficiency and reducing air bubble entrainment according to claim 1, characterized in that small grooves on the order of millimeters are formed on the surface of the upstream guide vane (6) so that the aspect ratio of the array is 1:2, and small grooves in an array are formed on the surface of the downstream guide vane (7).

Images