Center drainage type self-bubble-discharging die head

Abstract

The utility model relates to a center drainage type self-bubble-discharging die head. According to the center drainage type self-bubble-discharging die head, a center drainage die head cavity is formed in a center drainage die head body; the central drainage die head cavity comprises a flat liquid storage layer, a central drainage feeding channel, a drainage groove and a slit channel; in the gravity direction, the flat liquid storage layer and the drainage groove have the top positions of the same height, the center drainage feeding channel communicates with the top position of the drainage groove, and the drainage groove communicates with the slit channel through the flat liquid storage layer. In the horizontal direction, the thickness of the flat liquid storage layer is smaller than a preset thickness range, so that the coating has a state that the coating is in contact with the wall part of the flat liquid storage layer and flows downwards in the gravity direction under the action of gravity under the action of surface tension. In the whole process, the possibility of gas residue in the cavity of the central drainage die head is avoided, so that the problem that a slit channel at the bottom of the central drainage type self-bubble-discharging die head is quickly paved with the coating which quickly flows down under the action of gravity is solved from the source.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coating, in particular to a center drainage type self-foaming die. BACKGROUND

[0002] The coating die is one of the core components in the coating machine equipment, which is mainly used for uniformly coating various coatings on different types of substrates, including but not limited to slurry, glue, ink, etc. The application fields of the coating die include but are not limited to printing equipment, such as offset printing machine, intaglio printing machine, screen printing machine, etc.

[0003] The conventional coating die can be generally divided into T-shaped die as shown in Figure 1 , Figure 2 and Figure 3 , and coat hanger type die as shown in Figure 4 , Figure 5 and Figure 6 . Whether it is T-shaped die or coat hanger type die, the coating die 100 generally has a die body 110 and a die cavity 120 provided in the die body 110, and the die cavity 120 includes a liquid storage groove 121 and a feed passage 122, an exhaust passage 123 and a slit 124 which are respectively communicated with the liquid storage groove 121. The feed passage 122 is used for conveying the coating to the liquid storage groove 121; the liquid storage groove 121 conveys the coating to the slit 124, so that the coating flows out uniformly through the slit 124 with a certain thickness. The difference between the T-shaped die and the coat hanger type die lies in that the cross section of the liquid storage groove 121 of the T-shaped die is basically consistent; while the cross section of the liquid storage groove 121 of the coat hanger type die is smaller as the distance from the feed port is farther. In the conventional coating die, the feed passage 122 is generally located in the middle and upper part of the die cavity 120, and its function is to provide a channel for conveying the coating to the die cavity 120. The liquid storage groove 121 is located below the feed passage 122 and is communicated with the feed passage 122, and its function is to provide uniform pressure for the coating flowing into the slit 124, so that the coating can flow out from the slit 124; the slit 124 is located below the liquid storage groove 121 and is communicated with the liquid storage groove 121, and its function is to make the coating flow out uniformly with a certain thickness. The exhaust passage 123 is generally located on both sides of the die cavity 120, and its function is to provide a channel for the die cavity 120 to exhaust air, i.e. air bubbles.

[0004] However, whether it is T-shaped die or coat hanger type die, when the feeding starts, as shown in Figure 7 and Figure 8 , or as shown in Figure 9 and Figure 10 ,As shown, the coating 300 will quickly flow down under the action of gravity, so as to quickly spread on the bottom of the die cavity 120, and there is a high probability of bubbles in the middle. Therefore, the traditional coating die 100 cannot realize bubble discharge by itself, and needs to be additionally configured with an exhaust pipeline. The exhaust pipeline is connected with the exhaust passage 123 of the die cavity 120 to realize bubble discharge, so that the coating 300 can fill the die cavity 120. Among them, the bubble discharge is also called exhaust or bubble discharge. It is the process of filling the die cavity 120 with the coating 300 and discharging air before coating starts. Specifically, the traditional coating die 100 needs to be exhausted, i.e. bubble discharge, before coating starts. The exhaust process is the process of filling the die cavity 120 with the coating 300 and discharging air.

[0005] Moreover, the additional configuration of the exhaust pipeline needs to use an exhaust pipe, a valve and a related control module, thereby increasing the production process and increasing the cost due to the complex structure.

[0006] In addition, the bubble discharge of the traditional coating die 100 is time-consuming and insufficient, usually taking more than 5 minutes, and there may be residual air, which causes problems such as reduction of coating efficiency. Invention content

[0007] Therefore, it is necessary to provide a center drainage type self-bubble discharge die.

[0008] One embodiment of the present application is a center drainage type self-bubble discharge die, which comprises a center drainage die body;

[0009] The center drainage type self-bubble discharge die is provided with a center drainage die cavity in the center drainage die body;

[0010] The center drainage die cavity comprises a flat liquid storage layer, a center drainage feed passage, a drainage groove and a slit passage;

[0011] In the direction of gravity, the flat liquid storage layer and the drainage groove have the same height of the top position, the center drainage feed passage is communicated with the top position of the drainage groove, and the drainage groove is communicated with the slit passage through the flat liquid storage layer;

[0012] In the horizontal direction, the thickness of the flat liquid storage layer is less than the preset thickness range, so that the coating has a state of contacting the wall of the flat liquid storage layer and flowing downward in the direction of gravity due to the action of gravity under the action of surface tension.

[0013] The center drainage type self-foaming die head has a clever drainage design through cooperation of the flat liquid storage layer, the center drainage feeding channel, the drainage groove and the slit channel, so that the gravity of the coating and the surface tension of the coating reach a relative balance in the center drainage die head cavity, the coating slowly flows into the slit channel along the wall of the drainage groove and the flat liquid storage layer, and in the process of slowly flowing into the slit channel, the coating also slowly flows along the wall of the slit channel, and the possibility of gas remaining in the center drainage die head cavity is avoided, so that the problem of the coating rapidly flowing down under the action of gravity and rapidly spreading on the slit channel at the bottom of the center drainage type self-foaming die head is solved from the source, on the one hand, no additional exhaust pipeline is needed, and on the other hand, the bubble-removing process after feeding is cancelled, thereby being beneficial to improving the coating efficiency.

[0014] In some embodiments, the center drainage die head cavity has a symmetry plane, and the center drainage feeding channel communicates with the top position of the drainage groove at the symmetry plane; or,

[0015] The center drainage die head cavity only includes one drainage groove.

[0016] Exemplarily, the surface of the drainage groove adjacent to the flat liquid storage layer is in communication with the flat liquid storage layer.

[0017] In some embodiments, the flat liquid storage layer has a converging shape from bottom to top in the direction of gravity.

[0018] In some embodiments, the flat liquid storage layer has an isosceles triangular or fan-shaped cross-sectional shape.

[0019] In some embodiments, the drainage groove is a strip-shaped groove with a preset angle.

[0020] In some embodiments, the preset angle is 110 degrees to 160 degrees; or,

[0021] In the extension direction, the strip-shaped groove has a rectangular cross section.

[0022] In some embodiments, the flat liquid storage layer has a cuboid shape; or,

[0023] The slit channel is a cuboid, a prism with a straight-angle trapezoidal or isosceles trapezoidal cross section.

[0024] In some embodiments, in the horizontal direction, the connection position of the flat liquid storage layer and the slit channel is arranged to have the same width.

[0025] In some embodiments, the preset thickness range is less than 3 millimeters to 10 millimeters.

[0026] In some embodiments, the central flow channel is an opening or a tube. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0028] Figure 1 A structure diagram of a conventional coating T-shaped die.

[0029] Figure 2 A structure diagram of a conventional coating T-shaped die. Figure 1 A1-A1 direction sectional view of the embodiment shown.

[0030] Figure 3 A2-A2 direction sectional view of the embodiment shown. Figure 1 A2-A2 direction sectional view of the embodiment shown.

[0031] Figure 4 A structure diagram of a conventional coating clothes hanger-shaped die.

[0032] Figure 5 B1-B1 direction sectional view of the embodiment shown. Figure 4 B1-B1 direction sectional view of the embodiment shown.

[0033] Figure 6 B2-B2 direction sectional view of the embodiment shown. Figure 4 B2-B2 direction sectional view of the embodiment shown.

[0034] Figure 7 An internal diagram of the embodiment shown in use. Figure 1 An internal diagram of the embodiment shown in use. An internal diagram of the embodiment shown in use.

[0035] A3-A3 direction sectional view of the embodiment shown. Figure 8 A3-A3 direction sectional view of the embodiment shown. Figure 7 A3-A3 direction sectional view of the embodiment shown. A3-A3 direction sectional view of the embodiment shown.

[0036] An internal diagram of the embodiment shown in use. Figure 9 An internal diagram of the embodiment shown in use. Figure 4 An internal diagram of the embodiment shown in use. An internal diagram of the embodiment shown in use.

[0037] An internal diagram of the embodiment shown in use. Figure 10 A structure diagram of an embodiment of the center flow type self-foaming die described in the present application. Figure 9 A structure diagram of an embodiment of the center flow type self-foaming die described in the present application. A structure diagram of an embodiment of the center flow type self-foaming die described in the present application.

[0038] A structure diagram of an embodiment of the center flow type self-foaming die described in the present application. Figure 11 A structure diagram of an embodiment of the center flow type self-foaming die described in the present application. A structure diagram of an embodiment of the center flow type self-foaming die described in the present application.

[0039] A structure diagram of an embodiment of the center flow type self-foaming die described in the present application. Figure 12 A structure diagram of an embodiment of the center flow type self-foaming die described in the present application. Figure 11Another schematic diagram of the embodiment shown.

[0040] Figure 13 for Figure 12 A schematic diagram of the usage state in another direction of the embodiment shown.

[0041] Figure 14 for Figure 13 A cross-sectional view along the C1-C1 direction of the embodiment shown.

[0042] Figure 15 for Figure 14 A cross-sectional view along the C2-C2 direction of the embodiment shown.

[0043] Reference numerals: Coating die head 100, Die head body 110, Die head cavity 120, Liquid storage tank 121, Feed channel 122, Exhaust channel 123, Slit 124, Center-drained self-draining die head 200, Center-drained die head body 210, Center-drained die head cavity 220, Flat liquid storage layer 221, Center-drained feed channel 222, Drainage groove 223, Slit channel 224, Coating 300, Gravity direction 400, Horizontal direction 500. Detailed Implementation

[0044] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0045] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0048] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0049] To address the issues of traditional coating dies failing to automatically expel air bubbles, requiring additional venting pipes, and the time-consuming and insufficient bubble removal process, the applicant has proposed solutions along two technical paths, with this application representing one of them. This application discloses a center-draining self-draining bubble die, comprising some or all of the technical features of the following embodiments; that is, the center-draining self-draining bubble die includes some or all of the following structures. In one embodiment of this application, a center-draining self-draining mold head includes a center-draining mold head body; the center-draining self-draining mold head has a center-draining mold head cavity within the center-draining mold head body; the center-draining mold head cavity includes a flat liquid storage layer, a center-draining feed channel, a drainage groove, and a slit channel; in the direction of gravity, the flat liquid storage layer and the drainage groove have the same top height, the center-draining feed channel connects to the top of the drainage groove, and the drainage groove connects to the slit channel through the flat liquid storage layer; in the horizontal direction, the thickness of the flat liquid storage layer is less than a preset thickness range, so that the coating, under the action of surface tension, has a state of contacting the wall of the flat liquid storage layer and flowing downward in the direction of gravity due to gravity. The aforementioned center-draining self-draining die head employs a clever drainage design through the combination of a flat liquid storage layer, a central drainage feed channel, a drainage groove, and a slit channel. This design allows the coating's own gravity and surface tension to reach a relative balance within the central drainage die head cavity. The coating then slowly flows into the slit channel along the walls of the drainage groove and the flat liquid storage layer. Furthermore, during this slow flow into the slit channel, the coating also slowly descends along the walls of the slit channel. The entire process avoids the possibility of residual gas inside the central drainage die head cavity. Therefore, it fundamentally solves the problem of coating rapidly flowing down under gravity and quickly filling the slit channel at the bottom of the center-draining self-draining die head. This eliminates the need for additional venting pipes and the post-feeding de-foaming process, thereby improving coating efficiency. The following section will further elaborate on this design. Figures 1 to 15 The central drainage type self-draining foam mold head is described in detail.

[0050] In some embodiments, a centrally draining self-draining foam mold head 200 is as follows: Figure 11 and Figure 12 As shown, it includes a central drainage die head body 210; the central drainage self-draining die head 200 has a central drainage die head cavity 220 in the central drainage die head body 210; the central drainage die head cavity 220 includes a flat liquid storage layer 221, a central drainage feed channel 222, a drainage groove 223, and a slit channel 224; combined with Figure 13 and Figure 14In the direction of gravity 40°, the flat liquid storage layer 221 and the diversion channel 223 have the same top position. The central diversion feed channel 222 connects to the top position of the diversion channel 223, and the diversion channel 223 connects to the slit channel 224 through the flat liquid storage layer 221. Figure 14 and Figure 15 In the horizontal direction 500, the thickness of the flat liquid storage layer 221 is less than a preset thickness range, so that the coating 300, under the action of surface tension, has a state of contacting the wall of the flat liquid storage layer 221 and flowing downward in the gravity direction 400 due to gravity. This design, through the combination of a flat liquid storage layer 221, a central drainage feeding channel 222, a drainage groove 223, and a slit channel 224, employs a clever drainage design. This allows the coating 300 to achieve a relative balance between its own gravity and surface tension within the central drainage die head cavity 220. Consequently, the coating slowly flows into the slit channel 224 along the walls of the drainage groove 223 and the flat liquid storage layer 221. During this slow flow into the slit channel 224, the coating also slowly flows down along the walls of the slit channel 224. The entire process avoids the possibility of residual gas inside the central drainage die head cavity 220. Therefore, it fundamentally solves the problem of the coating 300 rapidly flowing down under gravity and quickly filling the slit channel 224 at the bottom of the central drainage self-draining die head 200. On the one hand, there is no need for additional venting pipes, and on the other hand, the defoaming process after feeding is eliminated, which is beneficial to improving coating efficiency.

[0051] In each embodiment, the centrally draining self-draining mold head 200 has a centrally draining mold head cavity 220 in the centrally draining mold head body 210; the centrally draining mold head cavity 220 includes a flat liquid storage layer 221, a centrally draining feed channel 222, a draining groove 223, and a slit channel 224; that is, the flat liquid storage layer 221, the centrally draining feed channel 222, the draining groove 223, and the slit channel 224 are an integral whole, each being a part of the centrally draining mold head cavity 220, and the flat liquid storage layer 221, the centrally draining feed channel 222, the draining groove 223, and the slit channel 224 are interconnected, so that the coating 300 flows from the centrally draining feed channel 222 through the draining groove 223 and the flat liquid storage layer 221 into the slit channel 224 under the action of gravity, and then flows out from the slit channel 224.

[0052] In various embodiments, the slit channel 224 may also be referred to as a slit, in order to avoid contact with... Figures 1 to 10 The traditional slit scheme is confused with the 124 phase and is thus named.

[0053] In some embodiments, the central drainage head cavity 220 has a symmetrical plane, such as... Figure 13As shown, the C1-C1 cross-sectional view is the symmetry plane; the central drainage feed channel 222 connects to the top of the drainage groove 223 at the symmetry plane; as an example, the flat liquid storage layer 221, the central drainage feed channel 222, the drainage groove 223 and the slit channel 224 all have symmetry planes, and each of the symmetry planes is arranged in the same way, that is, the flat liquid storage layer 221, the central drainage feed channel 222, the drainage groove 223 and the slit channel 224 have overlapping symmetry planes, therefore the central drainage self-draining foam die head 200 is called a central drainage design.

[0054] In some embodiments, the diversion groove 223 is located downstream of the central diversion feed channel 222 and is connected to the central diversion feed channel 222; as an example, the diversion groove 223 is connected to the lower end of the central diversion feed channel 222, and its function is to guide the paint 300 to flow to both ends of the central diversion die cavity 220 when the paint 300 flows into the flat liquid storage layer 221, that is, to guide the paint 300 to flow to both sides of the flat liquid storage layer 221. The flat liquid storage layer 221, also referred to simply as the liquid storage layer, is located downstream of the drainage channel 223 and is connected to the drainage channel 223. For example, the flat liquid storage layer 221 connects to the lower end of the drainage channel 223, or to the entire drainage channel 223, not limited to the upper, middle, or lower end. Its function is to allow the coating 300 to form sufficient surface tension in the flat liquid storage layer 221, i.e., the interlayer, thereby weakening the influence of gravity and achieving a relative balance between the gravity of the coating 300 and its surface tension in the central drainage head cavity 220, especially in the flat liquid storage layer 221. The slit channel 224 is located downstream of the flat liquid storage layer 221 and is connected to it. Its function is to allow the coating 300 to flow out uniformly with a certain thickness. This structural design overcomes the technical problem of traditional coating dies being unable to self-de-foam. By adopting a sandwich structure design, the surface tension and viscosity of the coating 300 are utilized to balance the influence of gravity on the coating 300, thus achieving self-de-foaming and enabling the center-draining self-de-foaming die 200 to have a self-de-foaming function. On the other hand, the thin-body design results in a smaller cavity volume and faster foam de-foaming, meaning that the center-draining self-de-foaming die 200 has higher foam de-foaming efficiency and less coating 300 loss.

[0055] Because it is a central drainage design, in some embodiments, such as Figure 13 As shown, the central drainage head cavity 220 includes only one drainage groove 223. For example, as... Figure 14 As shown, the surfaces of the drainage channel 223 adjacent to the flat liquid storage layer 221 are all connected to the flat liquid storage layer 221. In some embodiments, such as Figure 12 andFigure 13 As shown, the drainage channel 223 is a strip-shaped channel with a preset angle. In various embodiments, the preset angle is the included angle between the two sides of the drainage channel 223, that is, the included angle between the extending directions of the two sides of the drainage channel 223. In some embodiments, the preset angle is 110 degrees to 160 degrees; as an example, the preset angle is 120 degrees or 130 degrees. In some embodiments, the strip-shaped channel has a rectangular cross-section in the extending direction, that is, the drainage channel 223 has a rectangular cross-section. In other embodiments, the drainage channel 223 has an isosceles trapezoidal, semi-elliptical, or semi-circular cross-section. Compared with traditional T-shaped or coat hanger-shaped molds, this structural design of the present embodiment allows the paint 300 to flow down the wall of the flat liquid storage layer 221 at a relatively low speed and uniformly under the action of gravity through the drainage channel 223, thus fundamentally avoiding the possibility of gas residue inside the central drainage mold cavity 220. It is understood that the wall of the flat liquid storage layer 221 can also be understood as the inner wall of the central drainage head body 210, and therefore can also be called the inner wall or outer wall of the flat liquid storage layer 221.

[0056] In some embodiments, the central feed channel 222 is an opening, meaning the central feed die body 210 has an opening as the central feed channel 222 for receiving externally input paint 300. In some embodiments, the central feed channel 222 is a pipe; that is, the central feed die body 210 has a pipe or is connected to a pipe, with the inner cavity of the pipe serving as the central feed channel 222 for receiving externally input paint 300.

[0057] In each embodiment, along the gravity direction 400, the flat liquid storage layer 221 and the drainage channel 223 have the same top height, that is, the top position of the flat liquid storage layer 221 and the top position of the drainage channel 223 are at the same height. Figure 14 As shown. The central feed channel 222 connects to the top of the feed trough 223, and the feed trough 223 connects to the slit channel 224 through the flat liquid storage layer 221. As an example, when the paint 300 flows into the feed trough 223 through the central feed channel 222, part of it flows directly from the top of the feed trough 223 into the top of the flat liquid storage layer 221, part of it flows down through the feed trough 223 while flowing into the flat liquid storage layer 221, and the remaining part flows all the way to the bottom of the feed trough 223 and then into the flat liquid storage layer 221.

[0058] In various embodiments, the thickness of the flat liquid storage layer 221 in the horizontal direction 500 is less than a preset thickness range, so that the coating 300, under the action of surface tension, has a state of contacting the wall of the flat liquid storage layer 221 and flowing downward in the gravity direction 400 due to gravity. In some embodiments, the preset thickness range is less than 3 mm to 10 mm. As examples, the preset thickness range is less than 3 mm, 5 mm, 7 mm, 8 mm, or 10 mm. It is understood that the preset thickness range is usually set or adjusted according to the properties of the coating 300 itself, for example, based on flowability indicators such as viscosity. During the production process, under the action of the coating 300's own gravity, the coating 300 flows downward along the wall of the flat liquid storage layer 221. Since the thickness design of the flat liquid storage layer 221 takes into account both the action of the coating 300's own gravity and its own surface tension, the coating 300 will not flow downward like... Figures 1 to 10 Instead of flowing rapidly downwards like in traditional methods, the coating 300 flows slowly down the wall of the flat liquid storage layer 221, thus slowly flowing into the slit channel 224 along the drainage groove 223 and the wall of the flat liquid storage layer 221. During this slow flow into the slit channel 224, it also flows slowly down the wall of the slit channel 224. Therefore, in the process of injecting the coating 300 into the central drainage self-draining mold head 200, the entire process avoids the possibility of residual gas inside the central drainage mold head cavity 220. This solves the problem from the source that the coating 300 flows rapidly down under gravity and quickly fills the slit channel 224 at the bottom of the central drainage self-draining mold head 200. Moreover, compared to... Figures 1 to 10 Compared to traditional methods, this embodiment eliminates the need for additional venting pipes and removes the defoaming process after material feeding, thereby improving coating efficiency. Furthermore, by eliminating the defoaming process after material feeding, leakage of paint 300 from the slit channel 224 during the defoaming process is prevented, thus solving the problem of increased paint 300 consumption.

[0059] In some embodiments, in the direction of gravity 40°, such as Figure 15 As shown, the flat liquid storage layer 221 has a converging shape from bottom to top. In some embodiments, the flat liquid storage layer 221 has an isosceles triangular or fan-shaped cross-sectional shape. As an example, such as Figure 15 As shown, the flat liquid storage layer 221 has a shape combining isosceles triangles and rectangles. In some embodiments, the strip groove has a rectangular cross-section in the extending direction, that is, the drainage channel 223 has a rectangular cross-section. In other embodiments, the drainage channel 223 has an isosceles trapezoidal, semi-elliptical, or semi-circular cross-section. In some embodiments, the flat liquid storage layer 221 has a cuboid shape; as an example, such as Figure 15As shown, the flat liquid storage layer 221 has a combined shape of a cuboid and a triangular prism. In some embodiments, the slit channel 224 is a cuboid with a right-angled trapezoidal or isosceles trapezoidal cross-section. In some embodiments, such as Figure 15 As shown, in the horizontal direction 500, the connection position of the flat liquid storage layer 221 and the slit channel 224 is set with equal width. This structural design, on the one hand, helps the gravity and surface tension of the coating 300 to reach a relative balance in the flat liquid storage layer 221 and the drainage groove 223, so that it enters the slit channel 224 relatively slowly along the wall of the central drainage mold head body 210. In this way, during the injection of coating 300, the central drainage mold head cavity 220 is automatically vented along the slit channel 224, so there is no gas residue inside the central drainage mold head cavity 220. This solves the problem of gas residue caused by the rapid flow of coating 300 under gravity, which leads to the coating 300 quickly filling the slit channel 224 at the bottom of the central drainage self-draining mold head 200. It also avoids the problem of defoaming process after feeding caused by gas residue.

[0060] The following is combined with Figures 11 to 15 The application of the centrally draining self-draining bubbling head 200 will be further illustrated by examples. In some embodiments, the centrally draining bubbling head body 210 is made of a material with affinity coating 300, or the inner wall of the centrally draining bubbling head body 210 has a surface layer of material with affinity coating 300, in order to appropriately increase the contact rate with coating 300. In some embodiments, coating 300 enters the centrally draining bubbling head cavity 220 from the centrally draining feed channel 222, and then flows along the draining groove 223 towards the central region of the centrally draining bubbling head cavity 220, utilizing the surface tension formed by the flow of coating 300 in the interlayer to balance the effect of gravity, i.e., to weaken the effect of gravity. As the influence of gravity decreases, the coating 300, after entering the central drainage die cavity 220, will not flow directly and rapidly to the bottom slit channel 224, causing air bubble residue. Instead, it will advance from top to bottom, from the center to both sides, until it fills the flat liquid storage layer 221 of the central drainage die cavity 220, then enter the slit channel 224, and finally flow out of the slit channel 224. This achieves the self-draining function of the central drainage self-draining die 200, overcoming the technical problem that traditional coating dies cannot self-drain. Furthermore, the central drainage self-draining die 200 has a higher degassing efficiency, overcoming the problem of slow degassing and wasted coating 300 in traditional coating dies.

[0061] It should be noted that other embodiments of this application also include a centrally draining self-draining die head formed by combining the technical features of the above embodiments. This die head employs a clever drainage design through the cooperation of a flat liquid storage layer, a central drainage feed channel, a drainage groove, and a slit channel. This design allows the gravity of the coating material to reach a relative balance with its surface tension within the centrally draining die head cavity. Consequently, the coating material slowly flows into the slit channel along the walls of the drainage groove and the flat liquid storage layer. During this slow flow into the slit channel, the coating material also slowly flows down along the walls of the slit channel. The entire process avoids the possibility of residual gas inside the centrally draining die head cavity. Therefore, this solves the problem of the coating material rapidly flowing down under gravity and quickly filling the slit channel at the bottom of the centrally draining self-draining die head. On the one hand, there is no need to configure an additional venting pipe, and on the other hand, the defoaming process after feeding is eliminated, which is beneficial to improving coating efficiency.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. A center-draining self-draining bubble mold head (200), characterized in that, Including the central drainage head body (210); The central drainage self-draining mold head (200) has a central drainage mold head cavity (220) in the central drainage mold head body (210). The central drainage mold cavity (220) includes a flat liquid storage layer (221), a central drainage feed channel (222), a drainage groove (223), and a slit channel (224). In the direction of gravity (400), the flat liquid storage layer (221) and the diversion channel (223) have the same top position, the central diversion feed channel (222) connects to the top position of the diversion channel (223), and the diversion channel (223) connects to the slit channel (224) through the flat liquid storage layer (221). In the horizontal direction (500), the thickness of the flat liquid storage layer (221) is less than a preset thickness range, so that the coating (300) has a state of contacting the wall of the flat liquid storage layer (221) under the action of surface tension and flowing downward in the gravity direction (400) due to gravity.

2. The center-draining self-draining bubble mold head (200) according to claim 1, characterized in that, The central drainage die cavity (220) has a symmetrical plane, and the central drainage feed channel (222) connects to the top of the drainage groove (223) at the symmetrical plane; or, The central drainage head cavity (220) includes only one drainage groove (223).

3. The center-draining self-draining foam mold head (200) according to claim 1, characterized in that, In the direction of gravity (400), the flat liquid storage layer (221) has a converging shape from bottom to top.

4. The center-draining self-draining foam mold head (200) according to claim 3, characterized in that, The flat liquid storage layer (221) has an isosceles triangular or fan-shaped cross-sectional shape.

5. The center-draining self-draining bubble mold head (200) according to claim 1, characterized in that, The drainage channel (223) is a strip-shaped channel with a preset angle.

6. The center-draining self-draining bubble mold head (200) according to claim 5, characterized in that, The preset angle is between 110 degrees and 160 degrees; or, In the extending direction, the strip has a rectangular cross-section.

7. The center-draining self-draining bubble mold head (200) according to claim 1, characterized in that, The flat liquid storage layer (221) has a cuboid shape; or, The slit channel (224) is a cuboid with a cross-section of a right trapezoid or an isosceles trapezoid.

8. The center-draining self-draining bubble mold head (200) according to claim 1, characterized in that, In the horizontal direction (500), the connection position of the flat liquid storage layer (221) and the slit channel (224) is set with the same width.

9. The center-draining self-draining bubble mold head (200) according to claim 1, characterized in that, The preset thickness range is less than 3 mm to 10 mm.

10. The center-draining self-draining bubble mold head (200) according to any one of claims 1 to 9, characterized in that, The central feed channel (222) is an opening or a pipe.

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