Liquid feeding mechanism of roller coating method glass coating machine

Abstract

The utility model discloses a liquid feeding mechanism of a roller coating method glass coating machine, which is characterized in that a coating liquid stock solution barrel inputs coating liquid stock solution into a mixing and stirring barrel through a pipeline provided with a first peristaltic pump, and a diluent stock solution barrel inputs diluent into the mixing and stirring barrel through a pipeline provided with a second peristaltic pump; the mixing and stirring barrel is used for conveying uniformly stirred coating liquid to the roller coating method glass coating machine through a liquid feeding pump; the output end of a coating liquid reflux tank on the roller coating method glass coating machine is connected to the mixing and stirring barrel through a pipeline; the PLC is used for controlling the first peristaltic pump, the second peristaltic pump and the liquid feeding pump. The peristaltic pump and the PLC are adopted, the problem that in the prior art, when a controller and an electronic flow valve are adopted for control, due to the time delay of valve opening adjustment, the coating liquid concentration control precision is low is solved, and then the uniformity and consistency of coating thickness control are improved. Meanwhile, according to the improved scheme, two additional electronic scales are omitted.

Description

Technical Field

[0001] The utility model relates to a liquid applying mechanism, in particular to a liquid applying mechanism for a glass coating machine using a roller coating method. Background Art

[0002] As one of the primary materials used in photovoltaic modules, photovoltaic glass's performance significantly impacts the module's power generation output. While photovoltaic glass itself is colorless and transparent, applying an anti-reflective coating to ultra-clear rolled glass using a roller coating method can increase the glass's solar transmittance from 91.5% to over 93.5%. Consequently, the output power of crystalline silicon solar modules can be increased by 2% to 4%.

[0003] The principle of producing coated photovoltaic glass by roller coating is: use solar photovoltaic glass anti-reflection and anti-reflection coating liquid, and then use a roller coating machine to evenly apply the coating liquid to the surface of the photovoltaic glass. After surface drying and heating and curing, it enters the tempering furnace to obtain the coated photovoltaic glass.

[0004] In the roll-to-roll coating technology for photovoltaic glass, controlling film thickness is a core element. With the other control parameters of the coating machine unchanged, the concentration of the coating solution affects the film thickness and coating uniformity. The coating solution is primarily composed of silicon dioxide, and the solvent is typically an alcohol such as methanol, which acts as a diluent. Due to their high volatility, alcohol solvents are easily affected by ambient temperature and humidity. Therefore, when coating glass, the ambient temperature and humidity must be controlled. The coating chamber temperature is generally controlled at 20°C ± 5°C, and the humidity is generally controlled at 40% ± 5% to reduce concentration changes caused by volatilization of the coating solution. The coating production line uses a rubber roller to evenly apply the coating solution to the surface of the photovoltaic glass, with production speeds generally ranging from 13 to 15 meters per minute.

[0005] The uniformity and consistency of film thickness are crucial to the performance of photovoltaic glass. Uneven film thickness can cause light to reflect and scatter on the surface of the glass, reducing light transmittance and thus impacting the photovoltaic cell's power generation efficiency. Furthermore, insufficient or excessive film thickness can negatively impact the weather resistance and service life of the glass. To ensure uniform and consistent film thickness during the roller coating process, the coating solution concentration must be precisely controlled to ensure uniform application across the glass surface. Furthermore, enhanced quality inspection and control during the coating process are necessary to promptly identify and address uneven film thickness.

[0006] CN202766416U discloses a real-time concentration compensation device for glass liquid-phase coating production. Excess coating liquid returns to a mixed test liquid container through an AR coating liquid reflux tank. The coating liquid in the mixed test liquid is then transferred to an automatic test and replenishment machine via an AR coating liquid inlet and supply pump. The automatic test and replenishment machine analyzes the concentration and composition of the mixed coating liquid and compares them with the set coating liquid concentration and composition. The diluent in the diluent container is then injected into the mixed test container via the automatic test and replenishment machine via a diluent outlet pump. An agitator in the mixed test container continuously stirs and mixes the returned AR coating liquid and the newly injected diluent. When the AR coating liquid in the mixed test tank matches the set concentration and composition, the AR coating liquid outlet pump returns to the AR supply tank, ultimately achieving real-time concentration compensation for the coating liquid. This solution requires the use of additional specialized automatic test and replenishment equipment, increasing control costs and equipment failure rates.

[0007] CN220461200U discloses an automatic compensation device for film liquid in a coating machine. It uses an electronic scale to regularly detect the amount of film liquid stock solution used and the amount of diluent volatilized, and replenishes it in time through an electronic flow valve. On the one hand, it reduces labor and reduces the inaccuracy of labor. On the other hand, because the electronic scale and the electronic flow valve cooperate to accurately calculate and replenish the film liquid stock solution and diluent, the coating quality is improved and the dependence on manual technology is reduced. This solution requires the use of three high-precision electronic scales, two of which are used to weigh the weight of the film liquid stock solution barrel and the diluent barrel respectively. The electronic flow valve is controlled to replenish liquid according to the weight change. Since there is a certain time delay in the valve opening adjustment process of the electronic flow valve, the concentration control accuracy of the coating liquid in the upper liquid measuring cup is eventually reduced, thereby affecting the final coating thickness and uniformity. Summary of the Invention

[0008] Purpose of the invention: In view of the above-mentioned prior art, a liquid feeding mechanism for a glass coating machine using a roller coating method is proposed to improve the stability of the liquid feeding concentration.

[0009] Technical solution: A liquid feeding mechanism of a roller coating method glass coating machine, comprising a coating liquid stock liquid barrel, a diluent stock liquid barrel, a mixing and stirring barrel, a first peristaltic pump, a second peristaltic pump, a liquid feeding pump, and a PLC controller; wherein, the coating liquid stock liquid barrel inputs the coating liquid stock liquid to the mixing and stirring barrel through a pipeline provided with the first peristaltic pump, and the diluent stock liquid barrel inputs the diluent to the mixing and stirring barrel through a pipeline provided with the second peristaltic pump, and the mixing and stirring barrel conveys the evenly stirred coating liquid to the roller coating method glass coating machine through the liquid feeding pump; the bottom outlet of the coating liquid reflux tank on the roller coating method glass coating machine is connected to the mixing and stirring barrel through a pipeline; the PLC controller is used to control the first peristaltic pump, the second peristaltic pump, and the liquid feeding pump.

[0010] Furthermore, the PLC controller is a PLC controller on the roller coating glass coating machine.

[0011] Furthermore, it also includes an electronic balance, the mixing and stirring barrel is placed on the electronic balance, and the weighing result of the electronic balance is input into the PLC controller; the PLC controller is used to control the speed of the second peristaltic pump by positive feedback compensation according to the decrease in the weighing result of the electronic balance per unit time during the circulation process of the coating liquid in the mixing and stirring barrel and the roller coating glass coating machine under non-coating conditions.

[0012] Furthermore, the PLC controller is used to control the speed of the second peristaltic pump by positive feedback compensation based on the difference between the weight change of the electronic balance per unit time and the consumption of the coating liquid per unit time when only the first peristaltic pump is turned off under coating conditions.

[0013] Beneficial Effects: This new system utilizes a peristaltic pump and a PLC controller to address the low precision of coating solution concentration control due to the time delay in valve opening adjustment in conventional controllers and electronic flow valves. This improves the uniformity and consistency of coating thickness control. This improved solution also eliminates the need for two additional electronic scales.

[0014] Furthermore, by adding an electronic balance and cooperating with a PLC controller, the volatilization rate compensation of the diluent under the initial working environment temperature and humidity of the coating machine can be achieved.

[0015] Furthermore, the PLC controller is used to realize periodic automatic dynamic adjustment of the dilution liquid delivery speed compensation control during the coating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of the utility model's roller coating method glass coating machine;

[0017] Figure 2 It is a structural schematic diagram of the liquid feeding mechanism of the utility model. DETAILED DESCRIPTION

[0018] The present invention will be further explained below in conjunction with the accompanying drawings. Example

[0019] like Figure 1 、 Figure 2As shown, a liquid feeding mechanism for a roller coating glass coating machine includes a coating liquid stock tank 1, a diluent stock tank 2, a mixing and stirring tank 3, a first peristaltic pump 4, a second peristaltic pump 5, a liquid feeding pump 6, and a PLC controller. The coating liquid stock tank 1 feeds the coating liquid stock into the mixing and stirring tank 3 via a pipeline equipped with the first peristaltic pump 4, the diluent stock tank 2 feeds the diluent into the mixing and stirring tank 3 via a pipeline equipped with the second peristaltic pump 5, and the mixing and stirring tank 3 delivers the evenly stirred coating liquid to the roller coating glass coating machine 7 via the liquid feeding pump 6. The bottom outlet of the coating liquid reflux tank 8 on the roller coating glass coating machine is connected to the mixing and stirring tank 3 via a pipeline 9. The PLC controller is used to control the first peristaltic pump 4, the second peristaltic pump 5, and the liquid feeding pump 6.

[0020] The upper liquid pump 6 is also a peristaltic pump and is arranged on the corresponding pipeline. The PLC controller is the PLC controller on the common roller coating glass coating machine.

[0021] In this embodiment, the thickness of the glass coating layer is preset d , and preset coating roller speed S 1. Glass horizontal transmission speed S 2. The required concentration of the coating solution can be calculated based on existing theories ɑ , the precise speeds required for the corresponding first and second peristaltic pumps 4 and 5 can then be calculated. Under the control of the PLC controller, the first peristaltic pump 4 delivers the original coating solution to the mixing and stirring barrel 3 at a set speed, while the second peristaltic pump 5 delivers the diluted solution to the mixing and stirring barrel 3 at a set speed. The coating solution in the mixing and stirring barrel 3 is stirred evenly to a desired concentration. This solution is then pumped by the liquid pump 6 into the groove between the coating roller and anilox roller of the roller coating glass coating machine 7. As the coating roller 10 rotates, the coating solution is evenly applied to the upper surface of the glass.

[0022] This embodiment uses a peristaltic pump and a PLC controller to solve the problem of low coating solution concentration control accuracy caused by the time delay of valve opening adjustment when the controller and electronic flow valve are used in CN220461200U. At the same time, the improved solution also eliminates the need for two additional electronic scales. Example

[0023] On the basis of embodiment 1, an electronic balance 11 is further included, the mixing and stirring barrel 3 is placed on the electronic balance 11, and the weighing result of the electronic balance 11 is input into the PLC controller.

[0024] This embodiment adds an electronic balance 11 and cooperates with a PLC controller to achieve compensation for the volatilization rate of the diluent of the coating machine under the initial working environment temperature and humidity.

[0025] Specifically, in the initial working condition, that is, in the non-coating working condition, by controlling the first peristaltic pump 4, the second peristaltic pump 5, and the upper liquid pump 6, the coating liquid has achieved stable circulation between the mixing barrel 3 and the roller coating glass coating machine 7. Under this working condition, the decrease in the weighing result of the electronic balance 11 per unit time is the volatilization rate of the diluent in the coating machine system under the temperature and humidity of the current working environment. The PLC controller controls the speed of the second peristaltic pump 5 according to the positive feedback compensation of the volatilization rate, that is, by increasing the speed of the second peristaltic pump 5 to supplement the volatilization rate of the diluent, so as to achieve the accuracy of the concentration of the coating liquid finally coated on the glass surface. Example

[0026] On the basis of Example 2, at a fixed interval period, for example 30 minutes, when the PLC controller only turns off the first peristaltic pump 4 under the coating working condition, the PLC controller is used to control the speed of the second peristaltic pump 5 by positive feedback compensation based on the difference between the weighing change of the electronic balance 11 per unit time and the consumption of the coating liquid per unit time.

[0027] In the above process, the difference between the weighing change of the electronic balance 11 per unit time and the consumption of the coating liquid per unit time is the change in the volatilization rate of the diluent caused by the change in temperature or humidity in the working environment. The rotation speed of the second peristaltic pump 5 is controlled by positive feedback compensation based on the change, thereby realizing periodic automatic dynamic adjustment of the diluent delivery speed compensation control during the coating process.

[0028] The consumption of coating liquid per unit time can be set according to the preset thickness of the glass coating layer. d、 Coating solution concentration ɑ、 Glass horizontal conveying speed S 2. It can be calculated in advance mathematically based on existing theories; it can also be obtained by, after the last speed compensation control of the second peristaltic pump 5 is completed, in the equilibrium state, that is, when the coating thickness is qualified during the coating process, the PLC controller only turns off the first peristaltic pump 4, and reads the weighing change of the electronic balance 11 per unit time, which is the coating solution consumption per unit time.

[0029] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A liquid feeding mechanism for a glass coating machine using a roller coating method, characterized in that: The invention comprises a coating liquid stock barrel (1), a diluent stock barrel (2), a mixing and stirring barrel (3), a first peristaltic pump (4), a second peristaltic pump (5), a liquid top pump (6), and a PLC controller; wherein the coating liquid stock barrel (1) inputs the coating liquid stock into the mixing and stirring barrel (3) through a pipeline provided with the first peristaltic pump (4), the diluent stock barrel (2) inputs the diluent into the mixing and stirring barrel (3) through a pipeline provided with the second peristaltic pump (5), and the mixing and stirring barrel (3) conveys the uniformly stirred coating liquid to a roller coating method glass coating machine through the liquid top pump (6); the bottom outlet of the coating liquid reflux tank on the roller coating method glass coating machine is connected to the mixing and stirring barrel (3) through a pipeline (9); and the PLC controller is used to control the first peristaltic pump (4), the second peristaltic pump (5), and the liquid top pump (6).

2. The liquid feeding mechanism of the roller coating glass coating machine according to claim 1, characterized in that: The PLC controller is a PLC controller on the roller coating glass coating machine.

3. The liquid feeding mechanism of the roller coating glass coating machine according to claim 1 or 2, characterized in that: It also includes an electronic balance (11), the mixing and stirring barrel (3) is placed on the electronic balance (11), and the weighing result of the electronic balance (11) is input into the PLC controller; The PLC controller is used to control the rotation speed of the second peristaltic pump (5) by positive feedback compensation based on the decrease in the weighing result of the electronic balance (11) per unit time during the circulation process of the coating liquid in the mixing and stirring barrel (3) and the roller coating glass coating machine under non-coating working conditions.

4. The liquid feeding mechanism of the roller coating glass coating machine according to claim 3, characterized in that: The PLC controller is used to control the rotation speed of the second peristaltic pump (5) by positive feedback compensation based on the difference between the weighing change of the electronic balance (11) per unit time and the consumption of the coating liquid per unit time when only the first peristaltic pump (4) is turned off under coating working conditions.

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