Method for operating a vacuum fluorination apparatus and vacuum fluorination apparatus

Abstract

The application provides a vacuum fluorination device operation method and a vacuum fluorination device, and relates to the field of plastic treatment; the vacuum fluorination device operation method comprises the following steps: extracting gas in a cavity; filling nitrogen-fluorine mixed gas into the cavity; circulating the nitrogen-fluorine mixed gas on the surface of a plastic workpiece, so that the nitrogen-fluorine mixed gas fully contacts and reacts with the plastic workpiece; after the contact time of the nitrogen-fluorine mixed gas and the plastic workpiece reaches a preset time length, the gas in the cavity is extracted again; the cavity is filled with the first gas for multiple times to dilute the nitrogen-fluorine mixed gas in the cavity; and the cavity is filled with the second gas until the pressure in the cavity is balanced with the external pressure. Through the vacuum fluorination device operation method, the surface performance of the plastic workpiece is improved, and the printing effect of the water-based paint on the plastic workpiece is ensured.

Description

Technical Field

[0001] This application relates to the field of plastic processing, and more specifically, to an operating method of a vacuum fluorination apparatus and a vacuum fluorination apparatus. Background Technology

[0002] Currently, printing on plastic parts generally uses oil-based or water-based coatings. However, oil-based coatings pollute the environment, and the use of water-based coatings to replace them is becoming a trend. When water-based coatings are printed on plastic parts, the plastic parts are not compatible with the water-based coatings, resulting in poor printing effects and failing to meet the printing requirements of plastic parts. Therefore, how to improve the printing effect of plastic parts has become an urgent technical problem to be solved. Summary of the Invention

[0003] The purpose of this application is to provide an operating method and a vacuum fluorination device that can improve the printing effect of water-based coatings on plastic workpieces and play a role in protecting the environment.

[0004] In a first aspect, the present invention provides a method for operating a vacuum fluorination apparatus for processing plastic workpieces placed inside the cavity of the vacuum fluorination apparatus, the method comprising:

[0005] Extract the gas from the cavity until the pressure in the cavity drops to a first set pressure value;

[0006] The cavity is filled with a nitrogen-fluorine mixed gas until the pressure in the cavity rises to a second set pressure value;

[0007] The nitrogen-fluorine mixed gas circulates on the surface of the plastic workpiece, allowing the nitrogen-fluorine mixed gas to fully contact and react with the plastic workpiece;

[0008] After the contact time between the nitrogen-fluorine mixed gas and the plastic workpiece reaches the preset time, the gas in the cavity is extracted again until the pressure in the cavity drops to the third preset pressure value.

[0009] A first gas is introduced into the cavity to dilute the nitrogen-fluorine mixture inside the cavity;

[0010] A second gas is introduced into the cavity until the pressure inside the cavity is equal to the external pressure.

[0011] In an optional implementation, the first set pressure value is between 400 Pa and 500 Pa.

[0012] In an optional implementation, the second set pressure value is between 30,000 Pa and 36,000 Pa.

[0013] In an optional implementation, the third set pressure value is between 400 Pa and 500 Pa.

[0014] In an optional embodiment, the fluorine content of the nitrogen-fluorine mixed gas is less than 20%.

[0015] In an optional embodiment, the cavity is heated during the process of the nitrogen-fluorine mixed gas coming into full contact with the plastic workpiece, and the temperature of the cavity is maintained between 23°C and 60°C.

[0016] In an optional embodiment, both the first gas and the second gas are nitrogen.

[0017] Secondly, the present invention provides a vacuum fluorination apparatus for performing the operation method of the vacuum fluorination apparatus as described in the foregoing embodiments. The vacuum fluorination apparatus includes a vacuum fluorination system and a gas circulation system, wherein the vacuum fluorination system is connected to the gas circulation system.

[0018] In an optional embodiment, the vacuum fluorination system includes a cavity and a vacuum pump, the vacuum pump being connected to the cavity and the cavity being in communication with the gas circulation system.

[0019] In an optional embodiment, the gas circulation system includes an inlet pipe, an outlet pipe, and an internal circulation Roots pump. The internal circulation Roots pump is connected to the inlet pipe and the outlet pipe, respectively. The inlet pipe is installed in the upper part of the cavity, and the outlet pipe is installed in the lower part of the cavity.

[0020] Compared to existing technologies, the beneficial effects of this application are:

[0021] This application uses a vacuum fluorination device to fluorinate plastic workpieces, and then uses a gas circulation system to increase the contact between the nitrogen and fluorine mixed gas and the plastic workpieces, thereby improving the surface properties of the plastic workpieces, enhancing the affinity between the plastic workpieces and water-based coatings, and ensuring that the water-based coatings can adhere well to the plastic workpieces during printing. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A flowchart of the operation method of the vacuum fluorination device in Embodiment 1 is shown;

[0024] Figure 2Schematic diagrams of the vacuum fluorination system in some embodiments are shown;

[0025] Figure 3 A connection diagram of the vacuum fluorination apparatus is shown in some embodiments;

[0026] Figure 4 Schematic diagrams of vacuum fluorination apparatuses in some embodiments are shown.

[0027] Explanation of key component symbols:

[0028] 100-Vacuum fluorination system; 110-Cavity; 111-Heater; 120-Carrier; 121-Rotating wheel; 122-Baffle; 130-Vacuum pump; 200-Gas circulation system; 210-Inlet pipe; 220-Outlet pipe; 230-Internal circulation Roots pump; 300-Tail gas treatment system; 310-Exhaust pipe; 400-Gas supply system; 410-Nitrogen and fluorine gas source; 420-First inlet pipe; 430-Nitrogen gas source; 440-Second inlet pipe; 450-Nitrogen and fluorine gas control panel; 500-Electrical control system. Detailed Implementation

[0029] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0030] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0031] 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 one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0032] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] 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 is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply 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 that the first feature is at a lower horizontal level than the second feature.

[0034] Example 1

[0035] This embodiment is used to process plastic workpieces. Specifically, this embodiment is used to modify the surface of plastic workpieces so that water-based coatings can adhere well to the surface of the plastic workpieces, thereby improving the printing effect. The plastic workpieces referred to here include, but are not limited to, flat or curved products made of materials such as polypropylene (PP).

[0036] Please base on Figure 1 Referring to the following figures, this embodiment provides a method for operating a vacuum fluorination apparatus. This vacuum fluorination apparatus is used to process plastic workpieces placed within its cavity, and the method includes the following steps:

[0037] Please see Figure 2 .

[0038] The operation method of the vacuum fluorination device provided in this embodiment is used to process plastic workpieces placed in the cavity 110 of the vacuum fluorination device. Therefore, before the vacuum fluorination device is operated, the plastic workpiece is placed in the cavity 110 of the vacuum fluorination device.

[0039] In this embodiment, the cavity 110 is equipped with a switch door. First, the switch door is opened, and the pre-treated plastic workpiece is placed inside the cavity 110. After the switch door is closed, a sealed reaction space is formed inside the cavity 110. In this embodiment, multiple plastic workpieces are simultaneously subjected to vacuum fluorination treatment.

[0040] The aforementioned pretreatment processes include, but are not limited to, cleaning and drying. The surface of the pretreated plastic workpiece has a high degree of cleanliness, which facilitates the smooth progress of subsequent fluorination treatment.

[0041] To facilitate the transportation of workpieces and reduce the opening time of the door, this embodiment extends the opening corresponding to the door to be close to the ground. Multiple plastic workpieces are pre-placed on the carrier 120 with rotating wheels 121. The operator can directly push the carrier 120 into the cavity 110, which can quickly realize the transfer of plastic workpieces.

[0042] Specifically, the carrier 120 is equipped with multiple partitions 122, on which multiple plastic workpieces are placed horizontally. After the plastic workpieces are pre-placed outside the cavity 110, the carrier 120 is pushed into the cavity 110, which greatly reduces the time spent placing plastic workpieces inside the cavity 110. On the one hand, this reduces the waiting time of the equipment, and on the other hand, it reduces the opening time of the door, reduces the amount of gas leakage inside the vacuum fluorination equipment, maintains a good gas atmosphere, and reduces the adverse effects on the vacuum fluorination process.

[0043] Please see Figure 3 .

[0044] S100. Extract the gas from the cavity 110 until the pressure in the cavity 110 drops to the first set pressure value.

[0045] The vacuum pump 130 is started to evacuate the cavity 110. When the pressure in the cavity 110 drops to the first set pressure value, the operation of the vacuum pump 130 is stopped.

[0046] Understandably, in the initial state, the pressure inside cavity 110 is one standard atmosphere, i.e., 1.01325 × 10⁻⁶. 5 Pa.

[0047] At this time, the vacuum pump 130 is pumping out the gas (excluding the nitrogen-fluorine mixture) in the cavity 110. Due to the continuous elastic collisions between the gases, the greater the pressure, the more gas there is, and the greater the influence of the gas on the fluorination reaction, which reduces the reaction effect of the fluorination reaction. The purpose of evacuating is to reduce the interference of the gas in the cavity 110.

[0048] In other words, the less gas is retained in the cavity 110, the higher the proportion of nitrogen-fluorine mixed gas that is subsequently introduced, thereby enhancing the reaction effect of the fluorination reaction.

[0049] In this embodiment, the first set pressure value is between 400 Pa and 500 Pa. For example, when the pressure in cavity 110 is 1.01325 × 10⁻⁶ Pa, the pressure is between 400 Pa and 500 Pa. 5 When Pa drops to 450Pa, stop the operation of vacuum pump 130, and the first vacuuming is completed.

[0050] S200. Inject nitrogen-fluorine mixed gas into the cavity 110 until the pressure in the cavity 110 rises to the second set pressure value.

[0051] Since the gas in cavity 110 decreases after S100 is completed, nitrogen-fluorine mixed gas is then introduced into cavity 110 to fill it with nitrogen-fluorine mixed gas, thereby achieving the purpose of quickly replacing the gas with nitrogen-fluorine mixed gas.

[0052] The nitrogen-fluorine mixed gas mentioned here is formed by mixing nitrogen and fluorine. In this embodiment, the fluorine content of the nitrogen-fluorine mixed gas can be set to be less than 20%, which greatly improves the safety factor of fluorine use and avoids the danger of fluorine leakage during manufacturing, transportation, storage and production of high-concentration fluorine.

[0053] Understandably, the fluorine content in the nitrogen-fluorine mixture can be set even lower, for example, below 10%. The lower the fluorine content, the higher the safety. However, reducing the fluorine content also means reducing the efficiency of the fluorination reaction.

[0054] Similarly, the fluorine content in the nitrogen-fluorine mixture can be set even higher, for example, above 20%. This increases the efficiency of the fluorination reaction, but high concentrations of nitrogen-fluorine mixture pose certain dangers.

[0055] Operators can set the fluorine content reasonably based on safety factors and fluorination efficiency considerations.

[0056] Furthermore, nitrogen-fluorine mixed gas is polluting to the environment, while the cavity 110 in this embodiment is configured as a closed reaction space. The closed reaction space can reduce the risk of leakage of nitrogen-fluorine mixed gas, resulting in better production safety and protecting production safety.

[0057] In this embodiment, the second set pressure value is between 30000Pa and 36000Pa. For example, when the pressure in the cavity 110 rises from 450Pa to 35000Pa, the filling of nitrogen-fluorine mixed gas is stopped. At this time, the cavity 110 is basically filled with nitrogen-fluorine mixed gas.

[0058] S300. The nitrogen and fluorine mixed gas circulates on the surface of the plastic workpiece, allowing the nitrogen and fluorine mixed gas to fully contact and react with the plastic workpiece.

[0059] With continuous contact between the nitrogen and fluorine mixed gas and the plastic workpiece, a fluorinated layer is produced on the surface of the plastic workpiece through a reaction. The fluorinated layer is compatible with water-based coatings, which improves the adhesion rate of water-based coatings and ensures the printing effect of water-based coatings.

[0060] Please refer to the following: Figure 2 and Figure 3 During the process of starting the nitrogen-fluorine mixed gas to fully contact the plastic workpiece, the heater 111 is started to heat the cavity 110 and the temperature of the cavity 110 is maintained between 23°C and 60°C, for example, the temperature is maintained at 50°C.

[0061] In this embodiment, maintaining the temperature between 23°C and 60°C can effectively accelerate the fluorination reaction. If the temperature is below 23°C, the fluorination reaction will be slower and the fluorination effect will be poor. If the temperature is above 60°C, the plastic workpiece will overheat and deform, and the high temperature can easily cause workers to be burned, posing a potential safety risk.

[0062] It is understandable that the fluorination reaction can be achieved in this embodiment even without the heater 111. Compared with the method of using the heater 111, not using the heater 111 only affects the rate of the fluorination reaction.

[0063] Please continue reading. Figure 3 .

[0064] S400. After the contact time between the nitrogen and fluorine mixed gas and the plastic workpiece reaches the preset time, the gas in the cavity 110 is extracted again until the pressure in the cavity 110 drops to the third preset pressure value.

[0065] During operation, the gas circulation system 200 plays a role in stirring the nitrogen and fluorine mixed gas. In this embodiment, the preset time is set to 600s. After the preset time is reached, the fluorination reaction of the plastic workpiece is basically completed, and a complete fluorinated layer is formed on the surface of the plastic workpiece. At this time, the operation of the gas circulation system 200 is stopped.

[0066] Then restart the vacuum pump 130 to extract gas from the chamber 110. When the pressure inside the chamber 110 drops to the third set pressure value, stop the operation of the vacuum pump 130.

[0067] At this time, the vacuum pump 130 is started to extract the residual nitrogen and fluorine mixed gas. Since the nitrogen and fluorine mixed gas has a certain degree of pollution, it cannot be directly discharged into the external environment. At this time, it needs to be transferred to the exhaust gas treatment system 300 for purification after extraction.

[0068] In this embodiment, a vacuum pump 130 can be set up to extract the gas and nitrogen-fluorine mixed gas, so as to save the cost of vacuum pump 130 and pipeline laying. At this time, the output end of vacuum pump 130 must be connected to exhaust gas treatment system 300.

[0069] In some other embodiments, two vacuum pumps 130 can be used to extract the gas and the nitrogen-fluorine mixture gas respectively. In this case, the vacuum pump 130 used to extract the gas can be directly discharged into the air, while the vacuum pump 130 used to extract the nitrogen-fluorine mixture gas needs to be connected to the exhaust gas treatment system 300.

[0070] In this embodiment, the third set pressure value is between 400Pa and 500Pa. For example, when the pressure in the cavity 110 drops to 450Pa, the vacuuming stops. At this time, there is still some residual nitrogen and fluorine mixed gas.

[0071] S500. A first gas is introduced into the cavity 110 to dilute the nitrogen-fluorine mixed gas inside the cavity 110.

[0072] Specifically, the first gas can be repeatedly introduced into the cavity 110 and the gas in the cavity 110 can be extracted until the nitrogen-fluorine mixed gas in the cavity 110 is discharged.

[0073] The first gas is repeatedly introduced into the cavity 110 and the vacuum pump 130 is used to evacuate the cavity 110 to remove the nitrogen and fluorine mixed gas. This process of introducing gas and evacuating the vacuum is repeated multiple times.

[0074] The first gas does not react with the nitrogen-fluorine mixed gas. In this embodiment, the first gas can be set to nitrogen or dry air, etc. The first gas and some of the residual nitrogen-fluorine mixed gas in S400 are mixed a second time. After repeated inflation and vacuuming, the nitrogen-fluorine mixed gas is gradually vented.

[0075] Compared to directly venting the nitrogen-fluorine mixture, this embodiment can extend the residence time of the nitrogen-fluorine mixture in the cavity 110, resulting in a longer fluorination reaction time, a more complete reaction, and improved stability of the fluorinated layer. On the other hand, by gradually venting the nitrogen-fluorine mixture, this embodiment ensures that the fluorine content accounts for a smaller proportion of each vented gas, thus reducing the risk.

[0076] S600. Inflate the cavity 110 with a second gas until the pressure inside the cavity 110 is equal to the external pressure.

[0077] In this embodiment, the second gas can be set to nitrogen or air.

[0078] To reduce the amount of piping required, this embodiment sets both the first and second gases to nitrogen. In this case, only nitrogen delivery pipes need to be laid to allow the first and second gases to be introduced. The process of introducing the first and second gases is actually a series of purgings on the plastic workpiece. Under the action of multiple purgings, the plastic workpiece achieves convective cooling.

[0079] In some other embodiments, both the first gas and the second gas can be set to dry air, which can also reduce pipeline laying costs.

[0080] Of course, without considering cost, the first gas and the second gas can be set to be different gases, for example, the first gas is nitrogen and the second gas is air.

[0081] A second gas is introduced into cavity 110 to a standard atmosphere, at which point the pressure inside cavity 110 is balanced with the external pressure.

[0082] When the first gas and the second gas are set to the same gas (e.g., nitrogen), S600 and S500 can actually be combined into one step. Two implementation methods are provided here:

[0083] The first implementation method is to fill the cavity 110 with nitrogen until the pressure inside the cavity 110 rises to the fourth set value, then extract some gas, the pressure decreases, and then continue to fill the cavity 110 with nitrogen until the pressure inside the cavity 110 rises to the fourth set value, then extract some gas again, and repeat this cycle multiple times, and finally fill the cavity 110 with nitrogen until the pressure inside the cavity 110 is balanced with the external pressure.

[0084] The fourth setting value can be set to 600Pa or other settings. Other settings should be greater than the third setting pressure value and less than the external pressure.

[0085] The second implementation method is as follows: Nitrogen gas is introduced into the cavity 110 until the pressure inside the cavity 110 rises to the fifth set value. Then, some gas is extracted, the pressure decreases, and then nitrogen gas is introduced into the cavity 110 again until the pressure inside the cavity 110 rises to the sixth set value. Then, some gas is extracted, and nitrogen gas is introduced into the cavity 110 again until the pressure inside the cavity 110 rises to the seventh set value. Then, some gas is extracted, and so on. After repeating this cycle multiple times, nitrogen gas is finally introduced into the cavity 110 until the pressure inside the cavity 110 is balanced with the external pressure.

[0086] The fifth setting value can be set to 700 Pa, the sixth setting value can be set to 800 Pa, and the seventh setting value can be set to 900 Pa. That is, the fifth setting value, the sixth setting value, the seventh setting value and the subsequent setting values ​​increase in a stepwise manner, thereby reducing the pressure impact of the injected gas on the plastic workpiece and ensuring the stability of the fluorinated layer.

[0087] Of course, this embodiment does not limit other implementation methods.

[0088] Furthermore, after the fluorination reaction is completed in the vacuum fluorination unit, the operation of the vacuum fluorination unit is stopped, and the fluorinated plastic workpiece is removed.

[0089] Because the pressure inside cavity 110 is balanced with the external pressure, opening and closing the door can effectively prevent deformation and displacement of plastic workpieces, thus ensuring product quality.

[0090] Open the switch door and move the carrier 120 out of the cavity 110. At this time, the plastic workpiece has completed fluorination after S400 and has also undergone S500 and S600 treatments. The plastic workpiece has also completed cooling down and the temperature of the plastic workpiece has dropped to a normal level to avoid burns to the operator.

[0091] It is understandable that after a vacuum fluorination process is completed, the gas remaining in the cavity 110 is the first gas. If the next vacuum fluorination process is continued, the first gas will be the gas in S100.

[0092] In this embodiment, the plastic workpiece is fluorinated using a vacuum fluorination device, and the gas circulation system 200 can greatly increase the contact between the nitrogen and fluorine mixed gas and the plastic workpiece, improve the surface properties of the plastic workpiece, enhance the affinity between the plastic workpiece and the water-based coating, and ensure that the water-based coating can adhere well to the plastic workpiece during printing.

[0093] In practical applications, the operating temperature of the vacuum fluorination device ranges from 23 to 60°C. The specific operating temperature varies depending on the product material and process performance requirements. After treatment, the plastic workpiece can be activated with dyne solution for surface tension testing. Available dyne solution specifications include No. 46, No. 50, No. 58, No. 60, and No. 72, etc. The appropriate model of dyne solution is selected based on the product performance.

[0094] For example, the surface tension requirement for fluorinated plastic workpieces is 50 mN / m. We use No. 50 dyne solution for testing. We apply the dyne solution to three different locations on the surface of the plastic workpiece for about 2 seconds and observe whether the liquid film of the dyne solution shrinks. If there is no shrinkage, the process performance requirements are met. During printing, water-based coatings that meet the process performance requirements can adhere well to the plastic workpiece.

[0095] The surface tension of this embodiment is explained below using experimental data. The test reference temperature is 30°C. The nitrogen-fluorine mixed gas source contains 10% fluorine and 90% nitrogen. The nitrogen-fluorine mixed gas is input into a volume of 2.2 m³. 3 The fluorine content in the cavity 110 is between 4% and 5%. After fluorination is completed, a test is performed to obtain the surface tension data in the table below.

[0096]

[0097] As can be seen from the table above, after the fluorination treatment of the plastic workpiece in this embodiment, the surface tension of the material is greatly improved, making the plastic surface more compatible with water-based coatings, improving the adhesion rate of water-based coatings, ensuring printing effect, and playing a role in protecting the environment.

[0098] Example 2

[0099] Please see Figure 3 and Figure 4 This embodiment provides a vacuum fluorination device, which includes a vacuum fluorination system 100 and a gas circulation system 200, wherein the vacuum fluorination system 100 and the gas circulation system 200 are connected.

[0100] The vacuum fluorination system 100 includes a cavity 110 and a vacuum pump 130. The vacuum pump 130 is connected to the cavity 110. The cavity 110 is equipped with a switch door. First, the switch door is opened, and the pre-treated plastic workpiece is placed inside the cavity 110. After the switch door is closed, a sealed reaction space is formed inside the cavity 110.

[0101] In this embodiment, the following settings are made: both the first gas and the second gas are nitrogen, and the number of vacuum pumps 130 is one.

[0102] The cavity 110 is also provided with a first air inlet, a second air inlet, and an air outlet. The first air inlet is used to fill the cavity with a nitrogen-fluorine mixed gas, the second air inlet is used to fill the cavity with nitrogen, and the air outlet is connected to the vacuum pump 130 and is used to extract the gas in the cavity 110.

[0103] It is understood that the first air inlet is connected to the nitrogen and fluorine gas source 410 through the first air inlet pipe 420, and the second air inlet is connected to the nitrogen gas source 430 through the second air inlet pipe 440. A nitrogen and fluorine gas control panel 450 is provided on the first air inlet pipe 420 and the second air inlet pipe 440. In this embodiment, the nitrogen and fluorine gas control panel 450 can be used to accurately control the input amount and input speed of the nitrogen and fluorine mixed gas and nitrogen, so that the operator can make adaptive adjustments according to the fluorination process.

[0104] For ease of description and understanding, in this embodiment, the nitrogen and fluorine gas source 410, the first gas inlet pipe 420, the nitrogen gas source 430, the second gas inlet pipe 440, and the nitrogen and fluorine gas control panel 450 are defined as the gas supply system 400. The gas supply system 400 is connected to the vacuum fluorination system 100 to input gas into the vacuum fluorination system 100.

[0105] The gas output from the outlet is a residual nitrogen-fluorine mixture or nitrogen. Since the nitrogen-fluorine mixture is polluting, the vacuum fluorination device also includes a tail gas treatment system 300. The outlet and the tail gas treatment system 300 are connected through an exhaust pipe 310. The vacuum pump 130 is located on the exhaust pipe 310. The vacuum pump 130 extracts the nitrogen-fluorine mixture from the cavity 110 from the outlet and delivers it to the tail gas treatment system 300. The nitrogen-fluorine mixture can be discharged into the air only after being purified by the tail gas treatment system 300.

[0106] Please see Figure 2 A heater 111 is provided on the inner wall of the cavity 110. The heater 111 heats the cavity 110 and maintains the temperature of the cavity 110 between 23°C and 60°C.

[0107] Please continue reading Figure 3 and Figure 4 The gas circulation system 200 is connected to the cavity 110. The gas circulation system 200 includes an inlet pipe 210, an outlet pipe 220 and an internal circulation Roots pump 230. The internal circulation Roots pump 230 is connected to the inlet pipe 210 and the outlet pipe 220 respectively. The inlet pipe 210 is installed in the upper part of the cavity 110 and the outlet pipe 220 is installed in the lower part of the cavity 110.

[0108] Under the action of the internal circulation Roots pump 230, the nitrogen-fluorine mixed gas flows directionally from the top to the bottom of the plastic workpiece. Within a preset time, the nitrogen-fluorine mixed gas continuously contacts the plastic workpiece, and a fluorinated layer of a certain thickness is gradually formed on the surface of the plastic workpiece.

[0109] Furthermore, the vacuum fluorination unit also includes an electrical control system 500, which is used to control the start and stop of the various components mentioned above. The integrated electrical control system 500 allows operators to control the various components uniformly, making operation simple and eliminating the need for operators to move around the workshop multiple times, thus reducing the workload of operators and improving work efficiency.

[0110] This vacuum fluorination apparatus is used to operate the vacuum fluorination apparatus of Example 1, and has all the advantages of Example 1. Moreover, the structure of this embodiment is compact and the preparation cost is low.

[0111] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0112] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for operating a vacuum fluorination apparatus for processing plastic workpieces placed inside the cavity of the vacuum fluorination apparatus, characterized in that, include: Extract the gas from the cavity until the pressure in the cavity drops to a first set pressure value; The cavity is filled with a nitrogen-fluorine mixed gas until the pressure in the cavity rises to a second set pressure value; The nitrogen-fluorine mixed gas circulates on the surface of the plastic workpiece, allowing the nitrogen-fluorine mixed gas to fully contact and react with the plastic workpiece; After the contact time between the nitrogen-fluorine mixed gas and the plastic workpiece reaches the preset time, the gas in the cavity is extracted again until the pressure in the cavity drops to the third preset pressure value. A first gas is introduced into the cavity to dilute the nitrogen-fluorine mixture inside the cavity; A second gas is introduced into the cavity until the pressure inside the cavity is equal to the external pressure. The first set pressure value is between 400 Pa and 500 Pa; the second set pressure value is between 30000 Pa and 36000 Pa; and the third set pressure value is between 400 Pa and 500 Pa.

2. The method of operating the vacuum fluorination apparatus as described in claim 1, characterized in that, The fluorine content of the nitrogen-fluorine mixed gas is less than 20%.

3. The method of operating the vacuum fluorination apparatus as described in claim 1, characterized in that, During the process of the nitrogen-fluorine mixed gas coming into full contact with the plastic workpiece, the cavity is heated and the temperature of the cavity is maintained between 23°C and 60°C.

4. The method of operating the vacuum fluorination apparatus as described in claim 1, characterized in that, Both the first gas and the second gas are nitrogen.

5. A vacuum fluorination apparatus, characterized in that, A method for operating a vacuum fluorination apparatus as described in any one of claims 1 to 4, the vacuum fluorination apparatus comprising a vacuum fluorination system and a gas circulation system, wherein the vacuum fluorination system is connected to the gas circulation system.

6. The vacuum fluorination apparatus as described in claim 5, characterized in that, The vacuum fluorination system includes a cavity and a vacuum pump, the vacuum pump being connected to the cavity, and the cavity being connected to the gas circulation system.

7. The vacuum fluorination apparatus as described in claim 6, characterized in that, The gas circulation system includes an inlet pipe, an outlet pipe, and an internal circulation Roots pump. The internal circulation Roots pump is connected to the inlet pipe and the outlet pipe, respectively. The inlet pipe is installed in the upper part of the cavity, and the outlet pipe is installed in the lower part of the cavity.

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