PVC glove production line PVC trough body external circulation vacuum degassing system

Abstract

The application relates to the field of PVC glove production lines, in particular to a PVC glove production line PVC material tank body external circulation vacuum degassing system which comprises a recovery material box, a vacuum degassing tank, a circulating pipeline and a control assembly; the recovery material box is communicated with a PVC material tank and the vacuum degassing tank, the recovery material box is used for pumping mixed liquid at the bottom of the PVC material tank into the vacuum degassing tank, the vacuum degassing tank is provided with a plurality of vacuum degassing tanks and is used for pumping the mixed liquid in the tank body into liquid, the circulating pipeline is communicated with the vacuum degassing tank and the PVC material tank, and the circulating pipeline is used for conveying the liquid into the PVC material tank; the control assembly is used for controlling one of the vacuum degassing tanks to convey the liquid in the tank body into the PVC material tank while controlling the remaining vacuum degassing tanks to continue pumping the mixed liquid in the tank body into negative pressure. The application adopts the mode of pumping negative pressure to pump out the air in the mixed liquid, can effectively eliminate the air bubbles in the raw materials, and thus avoids the situation that the gloves have pinholes.

Description

Technical Field

[0001] This application relates to the field of PVC glove production lines, and more particularly to an external circulation vacuum degassing system for PVC material tanks in a PVC glove production line. Background Technology The main production process of PVC gloves is as follows: impregnation, dripping, primary baking, release agent impregnation, secondary baking, release molding, and final packaging. During the impregnation process, the hand mold is immersed in the prepared PVC material in a PVC bath as it moves along a chain. With the high-speed operation of the chain, the hand mold agitates the material in the PVC bath, generating a large number of air bubbles. Due to the viscosity of the material itself, some smaller air bubbles remain below the surface and cannot rise to the surface to escape. This causes the air bubbles to adhere to the hand mold during subsequent impregnation, resulting in pinholes in the finished PVC gloves, affecting their quality.

[0002] The common solution is to add a filter screen or other filtration equipment to the PVC material tank in order to filter out the air bubbles from the raw material. However, the effect of the filter screen is not significant for small air bubbles, and it is almost ineffective for very small air bubbles. Summary of the Invention

[0003] To effectively eliminate air bubbles in raw materials, this application provides an external circulation vacuum degassing system for the PVC material tank in a PVC glove production line.

[0004] The technical solution provided in this application for an external circulation vacuum degassing system for a PVC material tank in a PVC glove production line is as follows: A PVC glove production line PVC material tank external circulation vacuum degassing system includes a recycling bin, a vacuum degassing tank, circulation pipelines and control components; The recycling bin connects the PVC material tank and the vacuum degassing tank. The recycling bin is used to draw the mixed liquid from the bottom of the PVC material tank into the vacuum degassing tank. Multiple vacuum degassing tanks are provided, and each is used to draw negative pressure to form a liquid material from the mixed liquid inside the tank. The circulation pipe connects the vacuum degassing tank and the PVC material tank. The circulation pipe is used to transport the liquid material into the PVC material tank. The control component is used to control one of the vacuum degassing tanks to transport the liquid material inside the tank to the PVC material tank, while controlling the other vacuum degassing tanks to continue to draw negative pressure on the mixture inside the tank.

[0005] By adopting the above technical solution, the air bubbles generated by the hand mold entering and agitating the PVC material tank are partially located within the raw material, thus forming a mixture. The raw material in the PVC material tank is constantly being replenished. When new raw material is added, the liquid level of the original mixture in the PVC material tank rises and flows into a recycling bin for centralized processing. The control component can guide the mixture in the recycling bin into a vacuum degassing tank for degassing, eliminating air bubbles in the original mixture through negative pressure, turning it into a liquid. The control component then guides the liquid into a circulation pipe. Through the circulation pipe, the liquid recirculates into the PVC material tank, simultaneously raising the liquid level in the PVC material tank. The mixture overflows into an overflow tank for subsequent degassing, thus forming a cycle.

[0006] Furthermore, since there are multiple vacuum degassing tanks, the processes of the multiple vacuum degassing tanks are not carried out simultaneously. When one vacuum degassing tank delivers the liquid material to the PVC material tank, the other vacuum degassing tanks continue to work to achieve continuous degassing of the liquid material.

[0007] Compared to the existing technology that uses filtration, this application first removes the mixture from the PVC tank for centralized degassing, reducing the impact on other raw materials in the PVC tank without affecting the entire production line process. Secondly, since bubbles are air that fills the raw materials, the air in the mixture is extracted by using negative pressure, which can fundamentally and effectively eliminate bubbles in the raw materials, thereby avoiding pinholes in the gloves.

[0008] Optionally, the vacuum degassing tank includes a tank body, a vacuum pump, a material extraction control valve, a material feeding pump, a venting valve, and a material discharge control valve; Both the inlet and outlet are located in the tank body. The tank body is connected to a vacuum pump, which controls the vacuum state within the pipe. The material extraction control valve is connected to the inlet of the tank body and controls its connectivity. The feed pump is connected to the inlet of the tank body and to the recovery tank, pumping the mixture from the recovery tank into the tank body. The vent valve is connected to the tank body and controls the pressure relief within the tank. The discharge control valve is connected to the outlet and to the circulation pipe, guiding the depressurized liquid from the tank body into the circulation pipe. The vacuum pump, material extraction control valve, feed pump, vent valve, and discharge control valve are all connected to the control assembly.

[0009] By adopting the above technical solution, the vacuum pump is started, and the tank is initially under negative pressure. The opening of the material extraction control valve and the feeding pump allows the mixture in the recovery bin to be drawn into the tank. Because the tank is under negative pressure, the mixture can quickly fill the entire tank as the vacuum pump continues to work. Then, the material extraction control valve and the feeding pump are closed, and the vacuum pump continues to work to degas the mixture filled in the tank under negative pressure. Since the mixture fills the entire tank, the probability of the tank deforming due to the negative pressure is reduced. After the mixture is defoamed, it forms a liquid. After adjusting the pressure inside the tank to be the same as the external pressure through the venting valve, the discharge control valve is opened to smoothly introduce the liquid into the circulation pipeline, thereby completing the degassing process.

[0010] Optionally, the control component includes a PLC programmable controller and a first liquid level sensor and a second liquid level sensor connected to the PLC programmable controller; The vacuum pump, material extraction control valve, feeding pump, venting valve, and discharge control valve are all connected to a PLC programmable controller. The first liquid level sensor is installed in the recycling bin and is used to detect the liquid level of the mixture in the recycling bin. The recycling bin is set with a low liquid level. When the first liquid level sensor detects that the liquid level of the mixture in the recycling bin is higher than the low liquid level, it inputs a first liquid level signal to the PLC programmable controller, and the vacuum pump, the material extraction control valve, and the feeding pump are turned on. The second liquid level sensor is installed inside the tank to detect the liquid level of the mixture inside the tank. The tank is equipped with a high liquid level. When the second liquid level sensor detects that the liquid level of the mixture inside the tank is high, it inputs a second liquid level signal to the PLC programmable controller, and the material extraction control valve and the feeding pump are closed.

[0011] By adopting the above technical solution, in order to achieve automated control of the degassing process, high and low liquid levels are set in the recovery tank and the tank to control the degassing steps in the tank. The liquid level in the recovery tank is observed to control whether the mixed liquid is introduced into the tank for degassing. The liquid level of the mixed liquid in the tank controls the subsequent degassing steps in the tank. The entire process requires no operator or monitoring, and the precision is relatively higher than that of manual operation.

[0012] Optionally, the vacuum pump is connected to a first timer for timing the vacuum pump's start time. The first timer is connected to a PLC programmable controller. When the mixture in the tank is at a high level, the first timer starts, and the vacuum pump continues to run until the first timer's timing period ends, at which point it shuts off, and the tank enters the pressure-holding stage.

[0013] By adopting the above technical solution, in order to accurately control the time of negative pressure extraction in the tank, when the mixed liquid in the tank reaches the high liquid level, the tank is sealed and degassing begins. At this time, the first timer starts timing, and the duration of the first timer is the duration of the vacuum pump's last operation to extract negative pressure and degas. When the timing duration is reached, the vacuum pump stops extracting negative pressure, and the pressure holding stage begins, that is, the pressure of the material liquid in the tank is lower than the pressure outside the tank. At this time, the air bubbles remaining in the material liquid can gradually detach from the material liquid, and at the same time, the overall pressure in the material liquid tends to stabilize.

[0014] Optionally, a second timer is installed inside the tank. The second timer is connected to a PLC programmable controller. The second timer is turned on after the vacuum pump is turned off. The second timer is used to set the duration of the pressure holding stage inside the tank. After the pressure holding stage ends, the PLC programmable controller controls the vent valve to open, and the tank is depressurized.

[0015] By adopting the above technical solution, a second timer is set up to accurately control the pressure holding time. After pressure holding, the internal pressure of the liquid is stable but still lower than the external pressure of the tank. In order to allow the liquid to flow smoothly from the outlet into the circulation pipeline, the vent valve is opened to release pressure from the tank, so that the internal pressure of the tank is the same as the external pressure.

[0016] Optionally, the vent valve is connected to a third timer for controlling the opening time of the vent valve. The third timer is connected to a PLC programmable controller. The third timer starts when the vent valve opens. The vent valve closes after the third timer has been open for the specified duration, and the material discharge control valve opens.

[0017] By adopting the above technical solution, to avoid affecting the progress of the entire production line, the vent valve has a limited opening time to facilitate the rapid injection of liquid material into the PVC tank for recycling, thereby reducing the amount of raw material used in the PVC tank. When the timer expires, the vent valve closes, the discharge control valve opens, and the liquid material is introduced into the circulation pipeline.

[0018] Optionally, the opening duration of the discharge control valve is less than the sum of the timing durations of the first timer, the second timer, and the third timer.

[0019] By adopting the above technical solution, in order to ensure the normal operation of the entire PVC glove production line, it is necessary to limit the degassing time of the mixture so that the timing of each degassing process is at its optimal state, thereby improving the degassing efficiency.

[0020] Optionally, when the mixture in the multiple vacuum degassing tanks has not reached the high liquid level, the corresponding vacuum pump, material extraction control valve, and feeding pump are all turned on simultaneously. When the mixture in one of the vacuum degassing tanks reaches a high level, the operation continues to degas the mixture, while the liquid level in the other vacuum degassing tanks continues to rise. Once the vacuum degassing tank that has reached a high liquid level and completed the degassing process has introduced the degassed liquid into the circulation pipeline, the other vacuum degassing tanks will sequentially complete the subsequent processes.

[0021] By adopting the above technical solution, the processes of multiple vacuum degassing tanks are not uniform. While one vacuum degassing tank is degassing, the others continue to introduce the mixture. Only when the vacuum degassing tank that has completed degassing first introduces the degassed liquid into the PVC material tank through a circulation pipe can the other vacuum degassing tanks proceed to the next process. Therefore, after each degassing process is completed, only one vacuum degassing tank's liquid is introduced into the PVC material tank. The entire degassing process only allows one vacuum degassing tank to degas at a time, while the other vacuum degassing tanks are in the process of introducing the mixture. The degassing time of each vacuum degassing tank is the usage time of the raw material in the PVC material tank. When the degassed liquid is reintroduced into the PVC material tank, the newly generated mixture in the PVC material tank overflows into the recycling bin, thus forming a cycle and avoiding the occurrence of material discharge gaps.

[0022] Optionally, the volume of the recycling bin is not less than 1.5 times the volume of the PVC trough, and the volume of the tank is less than or equal to the volume of the PVC trough.

[0023] By adopting the above technical solution, the volume of the recycling bin is limited to ensure that at least two vacuum degassing tanks are in operation, thus reducing the material discharge gap. Furthermore, the operating procedures of each vacuum degassing tank are different to reduce the possibility of two or more vacuum degassing tanks simultaneously reaching their highest liquid levels. Since the tank volume is less than or equal to the PVC trough volume, the utilization rate of the original liquid within the PVC trough volume is increased, reducing waste.

[0024] Optionally, the circulation pipeline includes a discharge pump, a discharge pipe, and a discharge bend. The discharge pump is connected to the discharge pipe. One end of the discharge pipe is connected to the outlet of the vacuum degassing tank. The other end of the discharge pipe is inserted into the PVC trough from the bottom. The other end of the discharge pipe is connected to an L-shaped discharge bend. The end of the discharge bend facing away from the discharge pipe is located at the bottom of the PVC trough.

[0025] By adopting the above technical solution, in order to ensure a stable rise in the liquid level of the PVC tank during injection, the outlet of the discharge bend is oriented towards the bottom of the PVC tank. This guides the liquid downwards into the bottom of the PVC tank, slowing down the mixing speed between the liquid and the original raw materials in the PVC tank. This, in turn, pushes the original raw material level in the PVC tank higher, allowing as much of the original raw material in the PVC tank as possible to overflow into the overflow tank. On the one hand, this increases the amount of mixture entering the recycling bin. On the other hand, if the liquid level in the PVC tank is uneven, the adhesive surface of the hand mold will appear wavy and horseshoe-shaped during immersion, causing uneven edge thickness or tearing of the glove during subsequent lip-rolling. Therefore, a stable rise in the liquid level in the PVC tank ensures uniform adhesive thickness on the hand mold's wrist, thereby improving the quality of the glove's edge rolling.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. By removing the mixture from the PVC tank for centralized degassing, the impact on other raw materials in the PVC tank is reduced without affecting the entire production line process. Secondly, since bubbles are air that fills the raw materials, the air in the mixture is extracted by using negative pressure, which can fundamentally and effectively eliminate bubbles in the raw materials, thereby avoiding pinholes in the gloves. 2. In order to precisely control the time of negative pressure extraction in the tank, when the mixture in the tank reaches the high liquid level, the tank is sealed and degassing begins. At this time, the first timer starts counting. When the timer expires, the vacuum pump stops extracting negative pressure and enters the pressure holding stage. At this time, the air bubbles remaining in the liquid can be gradually removed from the liquid, and the overall pressure in the liquid tends to stabilize. 3. A second timer is set up to precisely control the pressure holding time. After pressure holding, the internal pressure of the liquid is stable but still lower than the external pressure of the tank. In order to allow the liquid to flow smoothly from the outlet into the circulation pipeline, the vent valve is opened to release pressure from the tank, so that the internal pressure of the tank is the same as the external pressure. Attached Figure Description

[0027] Figure 1 This is a process flow diagram of an external circulation vacuum degassing system for a PVC material tank in a PVC glove production line according to an embodiment of this application.

[0028] Figure 2 This is a schematic diagram of the structure of the control component in the embodiments of this application.

[0029] Figure 3 This is a connection diagram of the PLC programmable controller in an embodiment of this application.

[0030] Figure 4 This is a schematic diagram of the logical operation of an external circulation vacuum degassing system for a PVC material tank in a PVC glove production line according to an embodiment of this application.

[0031] Explanation of reference numerals in the attached figures: 1. Overflow trough; 2. Recycling bin; 3. Vacuum degassing tank; 31. Tank body; 32. Vacuum pump; 33. Material extraction control valve; 34. Feeding pump; 35. Vent valve; 36. Discharge control valve; 4. Circulation pipeline; 41. Discharge pump; 42. Discharge pipe; 43. Discharge bend; 5. Control components; 51. PLC programmable controller; 52. First liquid level sensor; 53. Second liquid level sensor; 54. First timer; 55. Second timer; 56. Third timer; 6. PVC material tank. Detailed Implementation

[0032] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0033] This application discloses an external circulation vacuum degassing system for the PVC material tank of a PVC glove production line.

[0034] It should be noted that, in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0035] Reference Figure 1 and Figure 2 The PVC production line's external circulation degassing system for PVC material tanks includes an overflow tank 1, a recovery tank 2, a vacuum degassing tank 3, a circulation pipeline 4, and a control component 5.

[0036] The overflow trough 1 is arranged around the PVC material tank 6 and connected to the upper surface of the PVC material tank 6, thereby collecting the mixture overflowing from the periphery of the PVC material tank 6. The overflow trough 1 is positioned lower than the PVC material tank 6 so that the mixture overflowing from the top of the PVC material tank 6 can completely flow into the overflow trough 1. The recycling bin 2 is connected to the overflow trough 1, so that the mixture flowing into the PVC material tank 6 can enter the recycling bin 2 for centralized collection. The inlet of the vacuum degassing tank 3 is connected to the bottom of the recycling bin 2, one end of the circulation pipe 4 is connected to the outlet of the vacuum degassing tank 3, and the other end of the circulation pipe 4 is connected to the PVC material tank 6. The control component 5 is connected to the vacuum degassing tank 3 and the circulation pipe 4. The control component 5 can control the vacuum degassing tank 3 to sequentially complete the processes of sucking up the mixture, drawing negative pressure on the mixture, and exporting the liquid. The control component 5 can also control the connection status of the circulation pipe 4 to facilitate the introduction of the degassed liquid into the PVC material tank 6.

[0037] In addition, the circulation pipeline 4 includes a discharge pump 41, a discharge pipe 42, and a discharge bend 43. The discharge pump 41 is connected to the discharge pipe 42. One end of the discharge pipe 42 is connected to the outlet of the vacuum degassing tank 3, and the other end of the discharge pipe 42 is inserted into the PVC tank 6 from the bottom and connected to the L-shaped discharge bend 43. The discharge bend 43 is located inside the PVC tank 6 and its end facing away from the discharge pipe 42 opens downwards and faces the bottom of the PVC tank 6. This causes the liquid being reintroduced into the PVC tank 6 to flow into the PVC tank 6 in a direction towards the bottom of the PVC tank 6, allowing the liquid in the PVC tank 6 to move smoothly from bottom to top, reducing the sloshing amplitude of the water surface in the PVC tank 6 when the liquid is injected into the PVC tank 6, and at the same time pushing the water level of the mixed liquid in the PVC tank 6 to overflow into the overflow tank 1, reducing the degree of mixing between the mixed liquid and the liquid, and improving the utilization rate of the liquid.

[0038] This application uses control component 5 to control the flow of the mixture in the recycling bin 2 into the vacuum degassing tank 3 for degassing treatment, thereby removing air from the mixture to form a liquid. The liquid is then introduced into the circulation pipe 4 through the outlet of the vacuum degassing tank 3, and then into the PVC material tank 6 for reuse. Compared with the prior art that uses filter screens or other filtration equipment to filter air bubbles, this application uses a negative pressure method to remove air, eliminating the need to consider the size of the air bubbles, thus fundamentally and effectively eliminating air bubbles in the raw materials and avoiding pinholes in gloves.

[0039] Meanwhile, this application removes the mixture from the PVC material tank 6 for degassing, and then re-introduces the liquid after negative pressure into the PVC material tank 6 for reuse, thereby reducing the impact of the degassing process on the entire production line.

[0040] Because existing technologies typically involve setting up filters within the PVC material tank 6, the liquid level inside the tank becomes unstable. This results in a wavy, horseshoe-shaped adhesive surface on the wrist of the hand mold during immersion, causing uneven edge thickness or tearing during the subsequent lip-rolling process. Therefore, the shape of the discharge bend 43 is designed to reduce the sloshing of the liquid surface in the PVC material tank 6 when the liquid is introduced into the tank. This allows the liquid level in the PVC material tank 6 to rise steadily, ensuring a uniform adhesive thickness on the wrist of the hand mold and thus improving the quality of the glove's edge rolling.

[0041] Reference Figure 1 The vacuum degassing tank 3 includes a tank body 31, a vacuum pump 32, a material extraction control valve 33, a material feeding pump 34, a venting valve 35, and a material discharge control valve 36.

[0042] Both the inlet and outlet are located in tank 31, which is connected to vacuum pump 32. Vacuum pump 32 controls the vacuum state within the tank. A material extraction control valve 33 is connected to the inlet of tank 31 to control its connectivity. A feed pump 34 is connected to the inlet of tank 31 and the recovery tank 2, pumping the mixture from the recovery tank 2 into tank 31. Only vacuum pump 32 applies negative pressure to the mixture, thus removing air from it. A vent valve 35 is connected to tank 31 and controls the depressurization state within it, ensuring that the pressure of the liquid after depressurization is the same as the external pressure of tank 31. A discharge control valve 36 is connected to the outlet and the circulation pipe 4, guiding the depressurized liquid from tank 31 into the circulation pipe 4, thus completing the degassing process of the mixture in vacuum degassing tank 3.

[0043] Among them, such as Figure 3 As shown, vacuum pump 32, material extraction control valve 33, feeding pump 34, vent valve 35 and discharge control valve 36 are all connected to control component 5. Control component 5 can control the opening status and opening and closing duration of vacuum pump 32, material extraction control valve 33, feeding pump 34, vent valve 35 and discharge control valve 36, thereby precisely controlling the degassing quality of the mixture.

[0044] Reference Figure 2 and Figure 3 The control component 5 includes a PLC programmable controller 51 and a first liquid level sensor 52 and a second liquid level sensor 53 connected to the PLC programmable controller 51. The vacuum pump 32, the material extraction control valve 33, the material feeding pump 34, the vent valve 35, and the material discharge control valve 36 are all connected to the PLC programmable controller 51.

[0045] The first liquid level sensor 52 is installed in the recycling tank 2 and can detect the liquid level of the mixture in the recycling tank 2. The recycling tank 2 is set with a low liquid level. When the first liquid level sensor 52 detects that the liquid level of the mixture in the recycling tank 2 is higher than the low liquid level, it inputs a first liquid level signal to the PLC programmable controller 51. The PLC programmable controller 51 controls the vacuum pump 32, the material extraction control valve 33 and the feeding pump 34 to open, so that the mixture can enter the tank 31.

[0046] Since the vacuum pump 32 is turned on, the air inside the tank 31 is reduced and the negative pressure is increased, so that the mixture can be quickly introduced into the tank 31, saving time.

[0047] Secondly, the second liquid level sensor 53 is installed inside the tank 31 and can detect the liquid level of the mixture inside the tank 31. The tank 31 is set with a high liquid level. When the second liquid level sensor 53 detects that the liquid level of the mixture inside the tank 31 is high, it inputs a second liquid level signal to the PLC programmable controller 51. The PLC programmable controller 51 can control the material extraction control valve 33 and the feeding pump 34 to close. At this time, the vacuum pump 32 continues to draw negative pressure on the tank 31. After the air in the tank 31 is completely drawn out, it starts to draw negative pressure on the mixture. The air in the mixture is extracted to form liquid, thereby achieving degassing of the mixture.

[0048] To limit the time for drawing negative pressure from the mixture, a first timer 54 is connected to the vacuum pump 32. The first timer 54 can time the start time of the vacuum pump 32. The first timer 54 is connected to the PLC programmable controller 51. When the mixture in the tank 31 is at a high level, the first timer 54 starts, and the vacuum pump 32 continues to run until the timer 54 stops. The timer duration of the first timer 54 is greater than or equal to 15 minutes to ensure sufficient degassing of the mixture in the tank 31.

[0049] After vacuum pump 32 is turned off, tank 31 enters the pressure holding stage, providing time for residual air in the liquid to further dissipate, and also allowing the pressure in different parts of the liquid to become more uniform, further improving the degassing effect of the mixture. A second timer 55 is installed inside tank 31, connected to the PLC programmable controller 51. The second timer 55 is activated after vacuum pump 32 is turned off. The duration of the pressure holding stage in tank 31 is set via the second timer 55, ensuring the liquid in tank 31 is completely stable before proceeding to the next step. For optimal stability, a timer duration of 30 minutes or more is recommended for the second timer 55.

[0050] After the pressure holding period ends, the liquid is still under negative pressure. In order to prevent the liquid from splashing when it is discharged from the outlet, the liquid needs to be depressurized so that the pressure of the liquid is the same as the external pressure of the tank 31.

[0051] Therefore, after the pressure holding stage, the PLC programmable controller 51 controls the vent valve 35 to open, and the tank 31 is depressurized. The vent valve 35 is connected to a third timer 56 that controls the opening time of the vent valve 35. The third timer 56 is connected to the PLC programmable controller 51. When the vent valve 35 opens, the third timer 56 opens simultaneously, and the vent valve 35 closes after the third timer 56 has been open for its designated duration. During the time the vent valve 35 is open, outside air enters the tank 31, and the pressure inside the liquid gradually equalizes with the pressure outside the tank 31 until the vent valve 35 closes. The timer 56 is maintained for at least 2 minutes to allow time for the pressure inside the liquid to stabilize and increase.

[0052] After the vent valve 35 is closed, the discharge control valve 36 opens, and the liquid enters the discharge pipe 42. Then, the discharge pump 41 is activated by the PLC programmable controller 51, which pumps the liquid into the discharge bend 43, allowing the liquid to re-enter the PVC tank 6 for use. At the same time, the liquid level in the PVC tank 6 rises, causing the mixture in the PVC tank 6 to overflow into the overflow tank 1, thereby realizing the circulation and degassing process of the air bubbles in the raw materials in the PVC tank 6. Moreover, the opening time of the discharge control valve 36 is less than the sum of the timing times of the first timer 54, the second timer 55, and the third timer 56, providing space and time for subsequent new mixture to enter the tank 31.

[0053] To ensure the normal operation of the entire glove production line, such as Figure 1 and Figure 4 As shown, there are multiple vacuum degassing tanks (3 units each), and the more vacuum degassing tanks (3 units each), the better. Figure 1 and Figure 4 Two vacuum degassing tanks are used as examples for demonstration.

[0054] When the mixture in all the vacuum degassing tanks 3 has not reached the high liquid level, the vacuum pumps 32, material extraction control valves 33, and feeding pumps 34 corresponding to all the vacuum degassing tanks 3 are turned on at the same time, and the mixture in the recovery tank 2 is sucked up.

[0055] Once the mixture in one of the vacuum degassing tanks 3 reaches a high level, degassing continues. Simultaneously, the other vacuum degassing tanks 3 that haven't reached a high level continue to draw mixture from the recovery tank 2 until the first vacuum degassing tank 3 to reach a high level completes the degassing process and imports the degassed liquid into the PVC tank 6. Only then can the other vacuum degassing tanks 3 that have reached a high level begin the next degassing process.

[0056] This means that only one vacuum degassing tank 3 can degas the mixture at any given time, while the other vacuum degassing tanks 3 are in the process of introducing the mixture. The degassing time of each vacuum degassing tank 3 is the same as the usage time of the raw material in the PVC material tank 6. When the degassed liquid is reintroduced into the PVC material tank 6, the newly generated mixture in the PVC material tank 6 will overflow into the recycling bin 2, thus forming a cycle and avoiding the occurrence of a material discharge gap.

[0057] Since the processes of multiple vacuum degassing tanks are not carried out simultaneously, when one vacuum degassing tank delivers the liquid to the tank, the other vacuum degassing tanks can continue to work to achieve continuous degassing of the liquid in the PVC tank 6.

[0058] Therefore, in order to achieve the cyclic process of degassing the mixture, the volume of the recovery tank 2 should be no less than 1.5 times the volume of the PVC tank 6, and the volume of the tank 31 should be less than or equal to the volume of the PVC tank 6, so that at least two vacuum degassing tanks 3 can degas alternately, thereby continuously degassing the mixture in the PVC tank 6 without affecting the volume of the raw materials in the PVC tank 6.

[0059] The implementation principle of the external circulation vacuum degassing system for the PVC material tank of a PVC glove production line according to an embodiment of this application is as follows: When the liquid level of the mixed liquid in the recovery tank 2 reaches the low level, the PLC programmable controller 51 controls the vacuum pump 32, the material extraction control valve 33, and the feeding pump 34 to open. The mixed liquid is drawn into the tank 31 until it reaches the high level in the tank 31. Then, the material extraction control valve 33 and the feeding pump 34 are closed, and the vacuum pump 32 continues to open to draw negative pressure into the mixed liquid, removing the air in the mixed liquid, and the mixed liquid forms a material liquid. After the vacuum pump 32 draws negative pressure into the mixture for the duration of the first timer 54, the vacuum pump 32 shuts off and enters the pressure holding stage. When the pressure holding stage reaches the duration of the second timer 55, the vent valve 35 opens, and the liquid in the tank 31 is in the pressure relief stage. When the pressure relief stage reaches the duration of the third timer 56, the vent valve 35 closes, the discharge control valve 36 opens, and the liquid is introduced into the circulation pipe 4 to enter the discharge stage. The liquid is pumped into the discharge bend 43 by the discharge pump 41, and the liquid flows from top to bottom into the PVC tank 6, causing the liquid level of the mixture in the PVC tank 6 to rise to overflow into the overflow tank 1, which ultimately effectively eliminates air bubbles in the raw materials and avoids pinholes in the gloves.

[0060] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A PVC material tank external circulation vacuum degassing system for a PVC glove production line, characterized in that: The system includes a recycling bin (2), a vacuum degassing tank (3), a circulation pipe (4), and a control component (5). The recycling bin (2) connects the PVC trough (6) and the vacuum degassing tank (3). The recycling bin (2) is used to draw the mixed liquid from the bottom of the PVC trough (6) into the vacuum degassing tank (3). The vacuum degassing tank (3) is provided with multiple tanks, each used to draw negative pressure to form a liquid mixture in the tank. The circulation pipe (4) connects the vacuum degassing tank (3) and the PVC trough (6). The circulation pipe (4) is used to transport the liquid mixture into the PVC trough (6). The control component (5) is used to control one of the vacuum degassing tanks (3) to transport the liquid mixture in the tank into the PVC trough (6). While the tank (6) is operating, the remaining vacuum degassing tanks (3) continue to draw negative pressure on the mixture inside the tank. The vacuum degassing tank (3) includes a tank body (31), a vacuum pump (32), a material extraction control valve (33), a material feeding pump (34), a venting valve (35), and a discharge control valve (36). The inlet and outlet are both located in the tank body (31). The tank body (31) is connected to the vacuum pump (32). The vacuum pump (32) is used to control the vacuum state inside the pipe. The material extraction control valve (33) is connected to the inlet of the tank body (31) and is used to control the connection state of the inlet. The material feeding pump (34) is connected to the inlet of the tank body (31) and the recovery tank (2). The mixture in the recycling bin (2) is pumped into the tank (31). The vent valve (35) is connected to the tank (31) and is used to control the depressurization state inside the tank (31). The discharge control valve (36) is connected to the outlet and the circulation pipe (4). The discharge control valve (36) is used to guide the liquid in the depressurized tank (31) into the circulation pipe (4). The vacuum pump (32), the material extraction control valve (33), the material pump (34), the vent valve (35), and the discharge control valve (36) are all connected to the control component (5). The control component (5) includes a PLC programmable controller (51) and a first liquid level sensor connected to the PLC programmable controller (51). The device (52) and the second liquid level sensor (53) are connected to the PLC programmable controller (51). The vacuum pump (32), the material extraction control valve (33), the material feeding pump (34), the vent valve (35) and the material discharge control valve (36) are all connected to the PLC programmable controller (51). The first liquid level sensor (52) is installed in the recycling tank (2) and is used to detect the liquid level of the mixture in the recycling tank (2). The recycling tank (2) is set with a low liquid level. When the first liquid level sensor (52) detects that the liquid level of the mixture in the recycling tank (2) is higher than the low liquid level, it inputs a first liquid level signal to the PLC programmable controller (51), and the vacuum pump (32), the material extraction control valve (33) and the material feeding pump (34) are turned on.The second liquid level sensor (53) is installed inside the tank (31) to detect the liquid level of the mixture inside the tank (31). The tank (31) is set with a high liquid level. When the second liquid level sensor (53) detects that the mixture inside the tank (31) is at a high liquid level, it inputs a second liquid level signal to the PLC programmable controller (51), and the material extraction control valve (33) and the feeding pump (34) are closed. The circulation pipeline (4) includes a discharge pump (41) and a discharge pipe (42). The discharge pump (41) is connected to the discharge pipe (42), one end of the discharge pipe (42) is connected to the discharge port of the vacuum degassing tank (3), and the other end of the discharge pipe (42) is inserted into the PVC trough (6) from the bottom. The other end of the discharge pipe (42) is connected to the L-shaped discharge bend (43), and the end of the discharge bend (43) facing away from the discharge pipe (42) is open downward and located at the bottom of the PVC trough (6).

2. The PVC material tank external circulation vacuum degassing system for a PVC glove production line according to claim 1, characterized in that: The vacuum pump (32) is connected to a first timer (54) for timing the start time of the vacuum pump (32). The first timer (54) is connected to a PLC programmable controller (51). When the mixture in the tank (31) is at a high level, the first timer (54) starts, and the vacuum pump (32) continues to start until the timing time of the first timer (54) is reached and then shuts off, and the tank (31) enters the pressure holding stage.

3. The PVC material tank external circulation vacuum degassing system for a PVC glove production line according to claim 2, characterized in that: A second timer (55) is installed inside the tank (31). The second timer (55) is connected to the PLC programmable controller (51). After the vacuum pump (32) is turned off, the second timer (55) is turned on. The second timer (55) is used to set the duration of the pressure holding stage inside the tank (31). After the pressure holding stage ends, the PLC programmable controller (51) controls the vent valve (35) to open, and the tank (31) is depressurized.

4. The PVC material tank external circulation vacuum degassing system for a PVC glove production line according to claim 3, characterized in that: The vent valve (35) is connected to a third timer (56) for controlling the opening time of the vent valve (35). The third timer (56) is connected to a PLC programmable controller (51). The third timer (56) is turned on when the vent valve (35) is turned on. The vent valve (35) is turned on until the third timer (56) has been turned on for the specified duration, after which it is turned off and the discharge control valve (36) is turned on.

5. The PVC material tank external circulation vacuum degassing system for a PVC glove production line according to claim 4, characterized in that: The opening duration of the discharge control valve (36) is less than the sum of the timing durations of the first timer (54), the second timer (55), and the third timer (56).

6. The PVC material tank external circulation vacuum degassing system for a PVC glove production line according to claim 4, characterized in that: When the mixture in the multiple vacuum degassing tanks (3) has not reached the high liquid level, the corresponding vacuum pump (32), material extraction control valve (33), and feeding pump (34) are all turned on simultaneously. When the mixture in one of the vacuum degassing tanks (3) reaches a high level, it continues to degas the mixture, and the liquid level in the other vacuum degassing tanks (3) continues to rise. After the vacuum degassing tank (3) that has reached a high liquid level and completed the degassing process introduces the degassed liquid into the circulation pipe (4), the other vacuum degassing tanks (3) complete the subsequent processes in sequence.

7. The PVC material tank external circulation vacuum degassing system for a PVC glove production line according to claim 1, characterized in that: The volume of the recycling bin (2) is not less than 1.5 times the volume of the PVC trough (6), and the volume of the tank (31) is less than or equal to the volume of the PVC trough (6).

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