Production equipment and production process of PTFE-PI film

Abstract

The application relates to a production device and production process of a PTFE-PI film, and relates to the technical field of composite processing devices. In order to solve the problem that the prepared composite film is prone to bubbles, the device comprises a device box, a first unwinding roller, a second unwinding roller, a corona area, a double-sided coating unit, an oven, a hot roller pressing mechanism and a winding mechanism are arranged in the device box, the double-sided coating unit comprises a slit coating head and a textured back roller, the slit coating head and the textured back roller respectively perform coating processes on two surfaces of a PI film, a scraper is arranged on the side, away from the slit coating head, of the textured back roller, the scraper scrapes off the excess adhesive on the textured back roller, and the water-based adhesive remaining on the textured back roller can be uniformly and reversely coated on one surface of the PI film. The application has the effects of reducing the bubble situation of the prepared composite film and improving the quality of the composite film.

Description

Technical Field

[0001] This application relates to the field of composite processing equipment technology, and in particular to a PTFE-PI film production equipment and production process. Background Technology

[0002] Polyimide (PI) is an aromatic heterocyclic polymer compound with imide chain segments in its molecular structure. It exhibits excellent high and low temperature resistance, allowing for long-term use within a temperature range of -200℃ to 300℃. PI also possesses superior mechanical properties and good acid and alkali resistance. With a dielectric constant of 3–4 and low dielectric loss, it is a material with great application potential in high-end dielectric substrates and packaging materials. Due to its high thermal stability, high strength and high modulus, excellent insulation properties, and dielectric properties, it is widely used in battery separators, aerospace, and electrical and electronic industries. However, polyimide has poor hydrophobicity; electronic components using it as a dielectric or substrate are prone to performance degradation or even failure due to excessive water absorption.

[0003] Polytetrafluoroethylene (PTFE) is widely recognized as the "king of plastics" and is the most widely used fluoroplastic globally. PTFE possesses excellent heat resistance, light resistance, chemical resistance, electrical insulation, and slip resistance, making it suitable for a wide range of applications, primarily in the mechanical, chemical, and electrical fields. Unlike polypropylene (PI), PTFE has excellent hydrophobic properties, thus greatly complementing PI's performance. Combining these two materials would significantly expand their application scenarios and lead to widespread use in many high-tech fields.

[0004] Existing laminating machines often produce composite films with uneven adhesive application or poor bonding during the lamination process, resulting in air bubbles. This application aims to improve existing laminating machines to produce composite films of higher quality. Summary of the Invention

[0005] To reduce the occurrence of air bubbles in the manufactured composite membrane, this application provides a PTFE-PI membrane production equipment and production process.

[0006] Firstly, this application provides a PTFE-PI membrane production equipment, which adopts the following technical solution:

[0007] A PTFE-PI film production device includes an equipment box, wherein the equipment box is equipped with...

[0008] The first unwinding roller is rotatably connected inside the equipment box for unwinding PI film;

[0009] The second unwinding roller is rotatably connected to the setting box for unwinding PTFE film;

[0010] A corona treatment zone is provided on one side of the first unwinding roller and is used to corona treat the PI film released from the first unwinding roller.

[0011] A double-sided coating unit includes a slot coating head and an anilox back roller. A corona-treated PI film passes between the slot coating head and the anilox back roller, with the slot coating head and the anilox back roller coating both sides of the PI film respectively. The anilox back roller is rotatably connected to the inner wall of the equipment housing. A glue tank for holding water-based adhesive is provided below the anilox back roller. One side of the PI film is wound around the anilox back roller. A doctor blade is provided on the side of the anilox back roller away from the slot coating head, and the doctor blade is located above the glue tank.

[0012] An oven is provided, comprising an inlet end into which a PI film treated by a double-sided coating unit enters, and an outlet end extending outward. The oven is provided with a first temperature zone and a second temperature zone that are connected to each other. The first temperature zone is located on the side near the inlet end, and the second temperature zone is located on the side near the outlet end. The temperature of the second temperature zone is higher than that of the first temperature zone.

[0013] The hot roll pressing mechanism includes a rubber roller and a high-temperature electromagnetic heating roller rotatably connected in the equipment box. The rubber roller and the high-temperature electromagnetic heating roller are tangent to each other and are used to press a PTFE film extending from the second unwinding roller structure and a PI film treated in an oven to prepare a PTFE / PI / PTFE composite film.

[0014] The winding mechanism includes a winding machine rotatably connected within the equipment housing and a drive source for driving the winding machine to rotate. The winding machine is used to wind up PTFE / PI / PTFE composite films.

[0015] By adopting the above technical solution, the PI film is unwound by the first unwinding roller to the corona treatment zone. After corona treatment, the PI film moves onto the anilox backing roller, which rotates in the opposite direction to the movement of the PI film. During rotation, the circumferential surface of the anilox backing roller comes into contact with the water-based adhesive in the adhesive tank, ensuring adhesion of the water-based adhesive to its circumferential surface. When the anilox backing roller rotates in the reverse direction, a doctor blade scrapes off excess adhesive, allowing the remaining water-based adhesive to be evenly applied to one side of the PI film, reducing the likelihood of air bubbles forming due to uneven adhesive application during subsequent multilayer film lamination.

[0016] The slot coating head evenly sprays the PI film that has not been coated by the anilox roller, so that both sides of the PI film are coated with water-based adhesive.

[0017] After coating, the PI film enters the first temperature zone and the second temperature zone to cure the water-based adhesive on the PI film. The PTFE film unwound by the second unwinding roller and the PI film are pressed together by the hot roller pressing mechanism to form a composite film. After being driven by the drive source to the edge trimming machine for edge trimming, the composite film is wound up by the winding machine.

[0018] Preferably, the corona zone is equipped with a corona machine, which includes a first corona roller and a second corona roller rotatably connected inside the equipment box. The first corona roller and the second corona roller are used for the PI film to pass around, and the outer walls of the first corona roller and the second corona roller abut against the PI film.

[0019] By adopting the above technical solution, one side of the PI film is wrapped around the outer curved surface of the first corona roller, and this side of the PI film is subjected to corona treatment. After one side of the PI film is corona treated, the other side of the PI film is wrapped around the second corona roller and subjected to corona treatment as well. The surface of the PI film after corona treatment is roughened, increasing the surface tension of the PI film, allowing the water-based adhesive to better adhere to both sides of the PI film, and reducing the possibility of air bubbles being generated during the subsequent lamination of the PTFE film and the PI film.

[0020] Preferably, a first traction roller rotatably connected to the side wall of the equipment box is provided between the first corona roller and the first unwinding roller, and a second traction roller rotatably connected to the side wall of the equipment box is provided between the second corona roller and the anilox back roller.

[0021] By adopting the above technical solution, the PI film is wound around the second traction roller after passing through the second corona roller. The PI film is pulled by the first traction roller and the second traction roller, so that tension is formed on the surface of the PI film. This strengthens the adhesion between the PI film and the circumferential surfaces of the first corona roller and the second corona roller, thereby reducing the amount of air entering between the PI film and the first or second corona roller, reducing the generation of back corona phenomenon, and thus enhancing the corona effect of the PI film.

[0022] Preferably, the equipment box is equipped with a storage tank for storing water-based adhesives, the storage tank is equipped with an adhesive supply pump, the adhesive tank and the adhesive supply pump are connected by an adhesive supply pipe, the adhesive supply pipe is connected to a branch pipe, and the other end of the branch pipe is connected to a slot coating head.

[0023] By adopting the above technical solution, the glue supply pump delivers the water-based adhesive from the storage tank to the slit coating head. The slit coating head can evenly spray the water-based adhesive onto the side of the PI film facing away from the anilox roller, thus ensuring that both sides of the PI film are evenly coated with the water-based adhesive. Simultaneously, the glue supply pump continuously supplies water-based adhesive to the glue tank through the glue supply pipe, allowing the anilox roller to operate continuously, saving time spent filling the glue tank with water-based adhesive and improving the equipment's operating efficiency.

[0024] Preferably, an overflow pipe is connected to the side wall of the glue tank near the top opening, and the end of the overflow pipe away from the glue tank is connected to the glue storage tank.

[0025] By adopting the above technical solution, when there is too much water-based adhesive in the glue tank, the portion of the water-based adhesive that exceeds the overflow pipe will flow back into the glue storage tank through the overflow pipe, reducing the probability of leakage caused by excessive water-based adhesive in the glue tank.

[0026] Preferably, the overflow pipe is connected to a branch pipe, the end of the branch pipe away from the overflow pipe is connected to the bottom wall of the glue tank, and a valve for opening and closing the branch pipe is installed on the branch pipe.

[0027] By adopting the above technical solution, when the anilox back roller stops running and there is still excess water-based adhesive remaining in the glue tank, the valve on the branch pipe is opened to allow the excess water-based adhesive to flow back into the glue storage tank for storage, which is convenient for subsequent reuse.

[0028] Furthermore, when there is too much water-based adhesive in the glue tank and the overflow pipe's discharge rate is insufficient, the valve is opened to allow the branch pipe and overflow pipe to discharge the water-based adhesive from the glue tank together, reducing the overflow of water-based adhesive from the glue tank and preventing waste of water-based adhesive.

[0029] Preferably, both the first and second temperature zones are provided with a plurality of rollers for supporting the transmission PI film, and the plurality of rollers are rotatably connected to the inner side wall of the oven. The distance between adjacent rollers in the first temperature zone is greater than the distance between adjacent rollers in the second temperature zone.

[0030] By adopting the above technical solution, when the length of the oven is too long, the PI film inside the oven will droop. When the PI film droops to the bottom of the oven, it will scrape off the water-based adhesive on the PI film, reducing the bonding strength of the PI film. Several rollers set inside the oven on the bottom wall of the oven play a supporting and transmission role for the PI film, reducing the amount of water-based adhesive scraped off the PI film.

[0031] Because the PI film in the first temperature zone is not completely dried, the water-based adhesive on the PI film will be scraped off when the roller rubs against the PI film, which reduces the adhesion of the PI film. Increasing the spacing between the rollers in the first temperature zone and reducing the number of rollers reduces the number of times the PI film rubs against the rollers in the first temperature zone, thereby strengthening the adhesion of the PI film.

[0032] Preferably, the roller is provided with multiple annular grooves intermittently, and the annular grooves on adjacent rollers are arranged in a staggered manner.

[0033] By adopting the above technical solution, when the PI film is conveyed on the roller, the PI film and the roller rub against each other, causing part of the water-based adhesive on the PI film to be scraped off. Multiple annular grooves are intermittently set on the roller to reduce the contact area between the roller and the PI film, which can effectively reduce the amount of water-based adhesive on the PI film scraped off by the roller. The annular grooves on adjacent rollers are staggered, so that the water-based adhesive on the contact surface between the PI film and the roller can be evenly distributed.

[0034] Preferably, a support roller is provided between the second unwinding roller and the hot roller pressing mechanism. The support roller is rotatably connected to the inner side wall of the equipment box and can move and lock on the side wall of the equipment box.

[0035] By adopting the above technical solution, adjusting the position of the support roller, the PTFE film is straightened, and then the position of the support roller is locked, which reduces the possibility of wrinkles on the PTFE film. Moreover, tension is formed on the straightened PTFE film, which makes the PTFE film adhere more tightly to the rubber roller and the electromagnetic heating roller, respectively, thereby enhancing the bonding effect between the PTFE film and PI and improving the quality of the prepared PTFE-PI composite film.

[0036] Secondly, this application provides a PTFE-PI membrane production process using the production equipment described above, including the following steps:

[0037] S1: Pull the PI film out from the first unwinding roller;

[0038] S2: The PI film passes through the corona zone, and both sides of the PI film are corona treated separately by a corona equipment;

[0039] S3: After corona treatment, the PI film passes through a double-layer coating unit, which simultaneously coats both sides of the PI film with water-based adhesive, uniformly coating both sides of the PI film.

[0040] S4: After the PI film is coated, it enters the drying oven to cure the water-based adhesive on the PI film and adhere it to the PI film surface.

[0041] S5: The PI film after passing through the oven enters the hot roller pressing mechanism; the PTFE film is pulled out from the second unwinding rollers on both sides of the hot roller pressing mechanism, and at the same time, the two layers of PTFE film and the treated PI film are combined into a three-layer sandwich structure PTFE / PI / PTFE composite film through the hot roller pressing mechanism.

[0042] S6: Finally, the winding machine rewinds the coil.

[0043] In summary, this application includes at least one of the following beneficial technical effects:

[0044] 1. When the anilox back roller rotates in reverse, the doctor blade scrapes off the excess adhesive on the anilox back roller, so that the water-based adhesive remaining on the anilox back roller can be evenly reverse-coated onto one side of the PI film, reducing the phenomenon of air bubbles caused by uneven adhesive application in subsequent multilayer film lamination.

[0045] 2. The first traction roller and the second traction roller pull the PI film, so that tension is formed on the surface of the PI film, thereby strengthening the adhesion between the PI film and the circumferential surface of the first corona roller and the second corona roller, and enhancing the adhesion between the PI film and the second corona roller. This reduces the amount of air entering between the PI film and the first or second corona roller, reduces the generation of back corona phenomenon, and thus enhances the corona effect of the PI film.

[0046] 3. Multiple annular grooves are intermittently set on the rollers to reduce the contact area between the rollers and the PI film, which can effectively reduce the amount of water-based adhesive on the PI film that is scraped off by the rollers. The annular grooves on adjacent rollers are staggered, so that the water-based adhesive can be evenly distributed on the contact surface between the PI film and the rollers. Attached Figure Description

[0047] Figure 1 This is a cross-sectional schematic diagram of a PTFE-PI membrane production equipment according to Embodiment 1 of this application;

[0048] Figure 2 This is a schematic diagram of the structure of the double-sided coating unit in Embodiment 1 of this application;

[0049] Figure 3 This is a schematic diagram of the overall cross-sectional structure inside the oven in Embodiment 1 of this application;

[0050] Figure 4 This is a schematic diagram of the hot rolling pressing mechanism and the winding mechanism in Embodiment 1 of this application;

[0051] Figure 5 This is a schematic diagram showing the roller arrangement in Embodiment 2 of this application;

[0052] Figure 6 This is a schematic diagram of the structure of the support roller slidingly connected to the side wall of the equipment box in Embodiment 3 of this application.

[0053] Explanation of reference numerals in the attached drawings: 1. Equipment box; 2. First unwinding roller; 21. PI film; 3. Corona zone; 31. First corona roller; 32. Second corona roller; 33. First traction roller; 34. Second traction roller; 4. Double-sided coating unit; 41. Anilox backing roller; 42. Adhesive tank; 43. Doctor blade; 44. Slot coating head; 45. Adhesive pump; 46. Glue storage tank; 47. Glue supply pipe; 471. Branch pipe; 48. Overflow pipe; 4 81. Branch pipe; 482. Valve; 5. Oven; 51. First temperature zone; 52. Second temperature zone; 53. Roller; 54. Annular groove; 6. Hot roller pressing mechanism; 61. Rubber roller; 62. High-temperature electromagnetic heating roller; 63. Second unwinding roller; 64. PTFE film; 7. Support roller; 71. Dovetail groove; 72. Dovetail block; 73. Bolt; 74. Groove; 8. Rewinding mechanism; 81. Edge trimmer; 82. Rewinder. Detailed Implementation

[0054] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0055] This application discloses a production equipment and process for PTFE-PI membrane.

[0056] Example 1:

[0057] A production equipment for PTFE-PI membrane, as described in the reference Figure 1 It includes an equipment box 1, which is rectangular in shape. Inside the equipment box 1 are a first unwinding roller 2, a corona zone 3, a double-sided coating unit 4, an oven 5, a hot roller pressing mechanism 6, a second unwinding roller 63, and a winding mechanism 8.

[0058] Reference Figure 1 The first unwinding roller 2 is rotatably mounted inside the equipment housing 1. A PI film 21 is wound onto the first unwinding roller 2. A corona treatment zone 3 is equipped with a corona treatment machine, which includes a first corona treatment roller 31 and a second corona treatment roller 32 that rotate inside the equipment housing 1 and whose axis is parallel to the first unwinding roller 2. The second corona treatment roller 32 is located directly above the first corona treatment roller 31, and one side of the PI film 21 is wrapped around and abuts against the first corona treatment roller 31. A first traction roller 33 is rotatably mounted inside the equipment housing 1, located below the first corona treatment roller 31 and parallel to the axis of the first corona treatment roller 31. The bottom of the first corona treatment roller 31 and the top of the first traction roller 33 are tangent to each other on the same horizontal plane. After the first traction roller 33 pulls the PI film 21 on the first unwinding roller 2, the PI film 21 is wound around the first corona treatment roller 31 in a horizontal direction.

[0059] The other side of the PI film 21 is attached to the circumferential surface of the second corona roller 32. A second traction roller 34 is rotatably arranged above the second corona roller 32 inside the equipment box 1. The bottom surface of the second traction roller 34 is tangent to the top surface of the second corona roller 32 and is on the same horizontal plane. After passing through the second corona roller 32, the PI film 21 is wound around the second traction roller 34. The PI film 21 is pulled by the first traction roller 33 and the second traction roller 34, so that tension is formed on the surface of the PI film 21. This strengthens the adhesion between the PI film 21 and the circumferential surface of the first corona roller 31 and the second corona roller 32, thereby reducing the air entering between the PI film 21 and the first corona roller 31 or the second corona roller 32, reducing the generation of back corona phenomenon, and thus enhancing the corona effect of the PI film 21.

[0060] The first corona roller 31 and the second corona roller 32 respectively corona treat both sides of the PI film 21, thereby roughening the surface of the PI film 21, increasing the surface tension of the PI film 21, and enabling the water-based adhesive to better adhere to both sides of the PI film 21, reducing the possibility of poor adhesion between the water-based adhesive and the PI film 21.

[0061] Reference Figure 1 The double-sided coating unit 4 includes an anilox back roller 41 rotatably mounted inside the equipment housing 1 and parallel to the first take-up roller. A motor (not shown in the figure) is rotatably connected to one side of the anilox back roller 41, and the end of the motor away from the anilox back roller 41 is fixed to the side wall of the equipment housing 1. A glue tank 42 is fixed inside the equipment housing 1, located below the anilox back roller 41. The glue tank 42 contains an aqueous adhesive. In this embodiment, the aqueous adhesive can be a suspension of PTFE dispersion resin, anhydrous ethanol, and a surfactant, preferably an alkyl quaternary ammonium cationic surfactant. The PTFE dispersion resin, anhydrous ethanol, and surfactant are mixed in a weight ratio of 2:200:1 and ultrasonically stirred to form a uniform suspension emulsion. A doctor blade 43 is fixedly connected inside the equipment housing 1, located on one side of the anilox back roller 41. The curved surface of the anilox back roller 41 away from the doctor blade 43 is bonded to the PI film 21.

[0062] The anilox roller 41 is driven to rotate by a motor mounted on the equipment housing 1. When the PI film 21 moves on the anilox roller 41, the rotation direction of the anilox roller 41 is opposite to the movement direction of the PI film 21. When the anilox roller 41 rotates, its outer curved surface can contact the water-based adhesive in the glue tank 42, so that the water-based adhesive is adhered to the outer curved surface of the anilox roller 41. When the anilox roller 41 rotates, the scraper 43 scrapes off the excess adhesive on the anilox roller 41, so that the water-based adhesive remaining on the anilox roller 41 can be evenly reverse-coated onto one side of the PI film 21, reducing the occurrence of air bubbles when the PTFE film 64 is laminated with the PI film 21. In addition, the water-based adhesive scraped off by the scraper 43 can fall into the glue tank 42, which saves raw materials.

[0063] Reference Figure 2 A glue storage tank 46 is fixedly connected to the inner bottom wall of the equipment box 1. The glue storage tank 46 contains water-based adhesive and is also equipped with a glue supply pump 45. A glue supply pipe 47 connects the glue tank 42 and the glue supply pump 45. A branch pipe 471 is connected to the glue supply pipe 47. The end of the branch pipe 471 away from the glue supply pipe 47 is connected to a slit coating head 44. The slit coating head 44 is located on the side of the PI film 21 away from the anilox roller 41 and is fixed to the inner side wall of the equipment box 1. An overflow pipe 48 is connected to the side wall of the glue tank 42. The end of the overflow pipe 48 away from the glue tank 42 is inserted into the glue storage tank 46. A branch pipe 481 is connected to the overflow pipe 48. The other end of the branch pipe 481 is connected to the bottom wall of the glue tank 42. A valve 482 is installed on the branch pipe 481.

[0064] The glue supply pump 45 delivers the water-based adhesive to the slot coating head 44, which then sprays the water-based adhesive evenly onto the side of the PI film 21 facing away from the anilox roller 41. Simultaneously, the glue supply pump 45 continuously delivers the water-based adhesive into the glue tank 42 through the glue supply pipe 47. When the height of the water-based adhesive in the glue tank 42 is level with or exceeds the overflow pipe 48, the portion of the water-based adhesive exceeding the height of the overflow pipe 48 flows out from the overflow pipe 48 into the glue storage tank 46, thereby realizing the function of circulating glue supply and maintaining a constant liquid level in the glue tank 42.

[0065] When the anilox back roller 41 stops operating and there is still excess water-based adhesive remaining in the glue tank 42, open the valve 482 on the branch pipe 481 to allow the excess water-based adhesive to flow back from the branch pipe 481 into the glue storage tank 46 for storage, so that it can be reused later.

[0066] Reference Figure 3The oven 5 has an inlet and an outlet on both sides, and a partition is installed in the middle of the oven 5. The partition has an opening for the PI film 21 to pass through, dividing the oven 5 into a first temperature zone 51 and a second temperature zone 52. The first temperature zone 51 is a low-temperature drying zone with an internal temperature of 80-110℃; the second temperature zone 52 is a high-temperature sintering zone with an internal temperature of 200-250℃. The first temperature zone 51 is located near the inlet of the oven 5, and the second temperature zone 52 is located near the outlet of the oven 5.

[0067] After the PI film 21 is coated, it enters the first temperature zone 51. After the water-based adhesive on both sides of the PI film 21 is dried by low-temperature baking, it enters the second temperature zone 52. Under the action of high temperature, the water-based adhesive on the PI film 21 is dried and cured on the surface of the PI film 21. This reduces the phenomenon that the residual solvent between the film layers cannot be released quickly during subsequent multilayer film lamination, which leads to the formation of bubbles on the film.

[0068] The oven 5 is equipped with several rollers 53, which are rotatably connected to the side wall of the oven 5. The distance between adjacent rollers 53 in the first temperature zone 51 is greater than the distance between adjacent rollers 53 in the second temperature zone 52. The rollers 53 provide support and transport for the PI film inside the oven 5. Because the PI film 21 in the first temperature zone 51 is not completely dried, the friction between the rollers 53 and the PI film 21 will scrape off the water-based adhesive on the PI film 21, reducing the adhesion of the PI film 21. Increasing the distance between the rollers 53 in the first temperature zone 51 and reducing the number of rollers 53 reduces the number of times the PI film 21 rubs against the rollers 53, thereby strengthening the adhesion of the PI film 21.

[0069] Reference Figure 4 The hot rolling pressing mechanism includes a rubber roller 61 and a high-temperature electromagnetic heating roller 62 rotatably connected within the equipment housing 1. The rotation axes of the rubber roller 61 and the high-temperature electromagnetic heating roller 62 are parallel to the first unwinding roller 2. The rubber roller 61 is located above the electromagnetic heating roller and is tangent to the high-temperature electromagnetic heating roller 62. There are two second unwinding rollers 63, respectively disposed on both sides of the rubber roller 61 and rotatably connected to the side wall of the equipment housing 1. A PTFE film 64 is wound on both second unwinding rollers 63. A support roller 7 is provided between each of the two second unwinding rollers 63 and the rubber roller 61, and the support roller 7 is rotatably connected to the side wall of the equipment housing 1.

[0070] After the PI film 21 is sintered and cured onto the film surface by the water-based adhesive in the oven 5, the PI film 21 and the PTFE film 64 unwound by the second unwinding rollers 63 on both sides of the rubber roller 61 are simultaneously fed into the hot roller pressing mechanism 6. The two layers of PTFE film 64 and PI film 21 are pressed together by the pressing between the rubber roller 61 and the high-temperature electromagnetic heating roller 62 to form a PTFE / PI / PTFE composite film.

[0071] Reference Figure 4The winding mechanism 8 includes an edge trimmer 81 and a winding machine 82. The edge trimmer 81 and the winding machine 82 are adjacent to each other, and both the edge trimmer 81 and the winding machine 82 are equipped with a drive source. After the PTFE / PI / PTFE composite film is edge trimmed by the edge trimmer 81, the winding machine 82 winds the finished PTFE / PI / PTFE composite film into a finished roll.

[0072] The implementation principle of a PTFE-PI film production equipment in Embodiment 1 of this application is as follows: PI film 21 is unwound by the first unwinding roller 2 and enters the corona treatment zone 3. One side of PI film 21 is wound around the first corona treatment roller 31 and subjected to corona treatment. After one side of PI film 21 has been treated by the first corona treatment roller 31, the untreated side of PI film 21 is wound around the second corona treatment roller 32 and subjected to corona treatment. The corona-treated PI film 21 enters the double-sided coating unit 4. One side of PI film 21 is coated with water-based adhesive through the slit coating head 44, and the other side of PI film 21 is coated with water-based adhesive through the anilox backing roller 41. After coating, PI film 21 enters the first temperature zone 51 from the inlet end of the oven 5 to dry the moisture in the water-based adhesive on both sides of PI film 21, and then enters the second temperature zone 52 to cure and sinter the polytetrafluoroethylene powder on the surface of the film onto the surface of PI film 21. The second unwinding rollers 63 on both sides simultaneously unwind the PTFE film 64, which enters the hot roller pressing mechanism 6 along with the dried PI film 21. The two layers of PTFE film 64 and the treated PI film 21 are pressed together by the rubber roller 61 and the high-temperature electromagnetic heating roller 62 to form a three-layer sandwich structure PTFE / PI / PTFE composite film. Finally, after being trimmed by the edge trimmer 81, it is wound up on the winding machine 82.

[0073] Example 2:

[0074] Reference Figure 5 The difference from Embodiment 1 is that multiple annular grooves 54 are formed on several rollers 53 arranged inside the oven 5, and the annular grooves 54 on adjacent rollers 53 are staggered. When the water-based adhesive bonded to the surface of the PI film 21 is conveyed on the rollers 53, the rollers 53 will rub off some of the water-based adhesive, which reduces the adhesion of the PI film 21. The annular grooves 54 on the rollers 53 reduce the contact area between the rollers 53 and the PI film 21, reducing the amount of water-based adhesive on the surface of the PI film 21 that is rubbed off. The staggered arrangement of the annular grooves 54 on adjacent rollers 53 allows the water-based adhesive on the contact surface between the PI film 21 and the rollers 53 to be evenly distributed, which is beneficial to the composite of the PTFE film 64 and the PI film 21, reduces the occurrence of bubbles or voids, and improves the quality of the PTFE / PI / PTFE composite film.

[0075] Example 3:

[0076] Reference Figure 6The difference from Embodiments 1 and 2 is that a dovetail groove 71 is provided on the side wall of the equipment box 1 along the vertical direction, and a groove 74 is located on the upper part of the dovetail groove 71 and communicates with the dovetail groove 71. The width of the groove 74 is equal to the width of the bottom wall of the dovetail groove 71. A dovetail block 72 is slidably arranged in the dovetail groove 71. One end of the support roller 7 is connected to a bearing, which is fixed in the dovetail block 72. A bolt 73 that abuts against the bottom wall of the dovetail groove 71 is threaded on the dovetail block 72.

[0077] The dovetail block 72 is placed in the groove and slid into the dovetail groove 71. The position of the dovetail block 72 in the dovetail groove 71 is adjusted and the position of the dovetail block 72 is fixed by the bolt 73, thereby adjusting the position of the support roller 7. This is used to straighten the PTFE membrane 64, reducing the possibility of wrinkles on the PTFE membrane 64. Tension will be formed on the straightened PTFE membrane 64, making the PTFE membrane 64 on both sides fit more tightly with the rubber roller 61 and the high-temperature electromagnetic heating roller 62, respectively. This enhances the bonding effect between the PTFE membrane 64 and the PI membrane 21 and improves the quality of the prepared PTFE / PI / PTFE composite membrane.

[0078] This application also discloses a manufacturing process for a PTFE-PI membrane, including the following steps:

[0079] S1. Pull the PI film 21 out from the first unwinding roller 2;

[0080] S2. The PI film 21 enters the corona zone. One side of the PI film 21 is wrapped around the first corona roller 31. The first corona roller 31 performs corona treatment on one side of the PI film 21. The side of the PI film 21 facing away from the first corona roller 31 is then wrapped around the second corona roller 32. The first corona roller 31 and the second corona roller 32 respectively perform corona treatment on both sides of the PI film 21, thereby roughening the surface of the film, increasing the surface tension of the PI film 21, and making the water-based adhesive better adhere to both sides of the PI film 21.

[0081] S3. After corona treatment, the PI film 21 passes through the double-sided coating unit 4, which evenly coats the water-based adhesive on both sides of the PI film 21.

[0082] S4. After the PI film is coated, it immediately enters the oven 5. The first temperature zone 51 is a low temperature drying zone to dry the moisture in the water-based adhesive on both sides of the PI film 21. The second temperature zone 52 is a high temperature sintering zone to solidify and sinter the polytetrafluoroethylene powder on the surface of the PI film 21.

[0083] S5. The PI film 21 after passing through the oven 5 enters the hot roller pressing mechanism 6; the PTFE film 64 on the second unwinding roller 63 on both sides of the rubber roller 61 is pulled out, and the two layers of PTFE film 64 and the treated PI film 21 are pressed together by the rubber roller 61 and the high temperature electromagnetic heating roller 62 to form a three-layer sandwich structure PTFE / PI / PTFE composite film.

[0084] S6. The PTFE / PI / PTFE composite film is cut by the edge trimmer 81 and then wound into a finished roll by the winding machine 82.

[0085] 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 PTFE-PI membrane production equipment, characterized in that: Includes an equipment box (1), and the equipment box (1) is provided with The first unwinding roller (2) is rotatably connected inside the equipment box (1) and is used to unwind the PI film (21). The second unwinding roller (63) is rotatably connected inside the equipment box (1) and is used to unwind the PTFE film (64). A corona zone (3) is provided on one side of the first unwinding roller (2) for corona treatment of the PI film (21) released from the first unwinding roller (2); The double-sided coating unit (4) includes a slot coating head (44) and an anilox back roller (41). The corona-treated PI film (21) passes between the slot coating head (44) and the anilox back roller (41), and the slot coating head (44) and the anilox back roller (41) respectively coat the two sides of the PI film (21). The anilox back roller (41) is rotatably connected to the inner wall of the equipment box (1). A glue tank (42) for holding water-based adhesive is provided below the anilox back roller (41). One side of the PI film (21) is wrapped around the anilox back roller (41). A scraper (43) is provided on the side of the anilox back roller (41) away from the slot coating head (44). The scraper (43) is located above the glue tank (42). The oven (5) includes an inlet end into which the PI film (21) after being treated by the double-sided coating unit (4) enters, and an outlet end extending out. The oven (5) is provided with a first temperature zone (51) and a second temperature zone (52) that are connected to each other. The first temperature zone (51) is located on the side near the inlet end, and the second temperature zone (52) is located on the side near the outlet end. The temperature of the second temperature zone (52) is higher than that of the first temperature zone (51). Rollers (53) for supporting and driving the PI film (21) are provided in both the first temperature zone (51) and the second temperature zone (52). The rollers (53) are rotatably connected to the inner wall of the oven (5). The distance between adjacent rollers (53) in the first temperature zone (51) is greater than the distance between adjacent rollers (53) in the second temperature zone (52). Multiple annular grooves (54) are intermittently provided on the rollers (53). The annular grooves (54) on adjacent rollers (53) are staggered. The hot roller pressing mechanism (6) includes a rubber roller (61) and a high-temperature electromagnetic heating roller (62) rotatably connected in the equipment box (1). The rubber roller (61) is tangential to the high-temperature electromagnetic heating roller (62) and is used to press a PTFE film (64) extending from the second unwinding roller (63) and a PI film (21) treated in the oven (5) to prepare a PTFE / PI / PTFE composite film. The winding mechanism (8) includes a winding machine (82) rotatably connected to the equipment box (1) and a drive source for driving the winding machine (82) to rotate. The winding machine (82) is used to wind up PTFE / PI / PTFE composite film. A support roller (7) is provided between the second unwinding roller (63) and the hot roller pressing mechanism (6). The support roller (7) is rotatably connected to the inner side wall of the equipment box (1) and can move and lock on the inner side wall of the equipment box (1). A dovetail groove (71) and a groove (74) located above the dovetail groove (71) and communicating with the dovetail groove (71) are provided on the side wall of the equipment box (1) in the vertical direction. The width of the groove (74) is equal to the width of the bottom wall of the dovetail groove (71). A dovetail block (72) is slidably provided in the dovetail groove (71). One end of the support roller (7) is connected to a bearing, which is fixed in the dovetail block (72). A bolt (73) that abuts against the bottom wall of the dovetail groove (71) is threaded on the dovetail block (72).

2. The PTFE-PI membrane production equipment according to claim 1, characterized in that: The corona zone (3) is equipped with a corona machine, which includes a first corona roller (31) and a second corona roller (32) rotatably connected in the equipment box (1). The first corona roller (31) and the second corona roller (32) are used for the PI film (21) to pass around, and the outer walls of the first corona roller (31) and the second corona roller (32) abut against the PI film (21).

3. The PTFE-PI membrane production equipment according to claim 2, characterized in that: A first traction roller (33) is rotatably connected to the side wall of the equipment box (1) between the first corona roller (31) and the first unwinding roller (2), and a second traction roller (34) is rotatably connected to the side wall of the equipment box (1) between the second corona roller (32) and the anilox back roller (41).

4. The PTFE-PI membrane production equipment according to claim 1, characterized in that: The equipment box (1) is equipped with a storage tank (46) for storing water-based adhesives. The storage tank (46) is equipped with a glue supply pump (45). The glue tank (42) and the glue supply pump (45) are connected by a glue supply pipe (47). A branch pipe (471) is connected to the glue supply pipe (47). The other end of the branch pipe (471) is connected to the slot coating head (44).

5. The PTFE-PI membrane production equipment according to claim 4, characterized in that: An overflow pipe (48) is connected to the side wall of the glue tank (42) near the top opening. The end of the overflow pipe (48) away from the glue tank (42) is connected to the glue storage tank (46).

6. The PTFE-PI membrane production equipment according to claim 5, characterized in that: The overflow pipe (48) is connected to a branch pipe (481). The end of the branch pipe (481) away from the overflow pipe (48) is connected to the bottom wall of the glue tank (42). A valve (482) for opening and closing the branch pipe (481) is installed on the branch pipe (481).

7. A process for producing a PTFE-PI membrane, using the PTFE-PI membrane production equipment as described in any one of claims 1-6, characterized in that: Includes the following steps: S1: Pull the PI film (21) out from the first unwinding roller (2); S2: The PI film (21) passes through the corona zone (3), and the two sides of the PI film (21) are corona treated by the corona equipment respectively; S3: The corona-treated PI film (21) passes through the double-sided coating unit (4), which coats both sides of the PI film (21) simultaneously, and evenly coats the water-based adhesive on both sides of the PI film (21). S4: After coating, the PI film (21) is placed in the oven (5) to cure the water-based adhesive on the PI film (21) and adhere it to the surface of the PI film (21); S5: The PI film (21) after passing through the oven (5) enters the hot roller pressing mechanism (6); the PTFE film (64) is pulled out from the second unwinding roller (63) on both sides of the hot roller pressing mechanism (6), and the two layers of PTFE film (64) and the treated PI film (21) are combined into a three-layer sandwich structure PTFE / PI / PTFE composite film through the hot roller pressing mechanism (6); S6: Finally, the winding machine (82) rewinds the coil.

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