Expanded polytetrafluoroethylene conductive sealing plate and manufacturing method thereof

Abstract

The present invention provides an expanded polytetrafluoroethylene (EPFE) conductive sealing plate and a method for manufacturing the same. The expanded polytetrafluoroethylene (EPFE) conductive sealing plate includes at least one expanded polytetrafluoroethylene (EPFE) conductive film layer, which includes an expanded polytetrafluoroethylene (EPFE) based film and a plurality of conductive fibers spaced apart on the expanded polytetrafluoroethylene (EPFE) based film. Each conductive fiber penetrates the expanded polytetrafluoroethylene (EPFE) based film and includes a penetration portion and extension portions connected to opposite ends of the penetration portion. The extension portion at each end is inclined and bent relative to the penetration portion, and the extension portions of the plurality of conductive fibers overlap to form conductive surface layers on opposite sides of the expanded polytetrafluoroethylene (EPFE) based film. The expanded polytetrafluoroethylene (EPFE) conductive sealing plate provided by the present invention not only has the advantages of high and low temperature resistance and good sealing performance, but also has good conductivity and a stable structure, capable of achieving an overall conductive effect.

Description

Technical Field

[0001] The present invention relates to the technical field of polytetrafluoroethylene materials, in particular to an expanded polytetrafluoroethylene conductive sealing plate and a manufacturing method thereof. Background Art

[0002] Expanded polytetrafluoroethylene (EPFE) is made from polytetrafluoroethylene resin through special processing methods such as stretching. It has a network structure formed by interconnected microfibers, with countless fine pores between these microfibers. EEPFE exhibits excellent chemical and abrasion resistance, as well as strong high and low temperature resistance. Its large number of pores allows it to be used in applications requiring high-temperature sealing and low weight requirements. Due to its excellent electrical insulation properties, EPFE resin can be used as a packaging material for electrical wires, among other applications. However, in some specialized applications, simultaneous sealing and electrical conductivity are required to facilitate the transmission of electrical signals. Therefore, there is a need to develop conductive EEPFE sealing materials that offer both high and low temperature resistance, excellent sealing properties, and the advantages of conductivity.

[0003] However, during the stretching process of expanded PTFE, it is difficult to mix in other conductive materials (such as conductive particles) to obtain conductive expanded PTFE: the addition of materials other than PTFE particles will make it difficult for the expanded PTFE to form fibers during the stretching process and thus prevent it from forming a film. Therefore, it is difficult to prepare conductive expanded PTFE films by adjusting the formula to add conductive materials, and thus it is impossible to produce conductive expanded PTFE seals.

[0004] Current expanded polytetrafluoroethylene (EPF) conductive materials are typically made by coating the surface of expanded polytetrafluoroethylene with a conductive material (for details, see patents such as CN107446156A). After drying, a conductive layer forms on the surface of the expanded polytetrafluoroethylene. However, because the conductive layer is only applied to the surface of the expanded polytetrafluoroethylene and the surface energy of expanded polytetrafluoroethylene itself is relatively low, it is difficult to combine with other materials (primarily because the fluorine atoms in expanded polytetrafluoroethylene are highly polar. When fluorine atoms combine with other elements, they essentially capture electrons from the outermost layer, forming a stable structure with eight electrons; therefore, it is difficult for other groups to generate van der Waals forces with it). As a result, the conductive layer of this structure easily falls off the expanded polytetrafluoroethylene surface, resulting in poor structural stability and affecting its normal use. Summary of the Invention

[0005] The purpose of the present invention is to provide an expanded polytetrafluoroethylene conductive sealing plate, which not only has the advantages of high and low temperature resistance and good sealing, but also has good conductivity and a stable structure, and can achieve the effect of overall conductivity (not just surface conductivity).

[0006] The present invention provides an expanded polytetrafluoroethylene (EPFE) conductive sealing plate, comprising at least one expanded polytetrafluoroethylene (EPFE) conductive film layer, wherein the expanded polytetrafluoroethylene (EPFE) conductive film layer comprises an expanded polytetrafluoroethylene (EPFE) based film and a plurality of conductive fibers spaced apart on the expanded polytetrafluoroethylene (EPFE) based film; each conductive fiber penetrates the expanded polytetrafluoroethylene (EPFE) based film along the thickness direction of the expanded polytetrafluoroethylene (EPFE) based film, and each conductive fiber comprises a penetration portion and protruding portions connected to opposite ends of the penetration portion; the penetration portion is located within the expanded polytetrafluoroethylene (EPFE) based film, and the protruding portions at opposite ends are respectively located on opposite sides of the expanded polytetrafluoroethylene (EPFE) based film; the protruding portion at each end is inclined and bent relative to the penetration portion, and the protruding portions of the plurality of conductive fibers overlap each other to form conductive surface layers on opposite sides of the expanded polytetrafluoroethylene (EPFE) based film.

[0007] In one achievable manner, the protruding portion is bent and abuts against the surface of the expanded polytetrafluoroethylene-based film, so that the conductive surface layer is in contact with the surface of the expanded polytetrafluoroethylene-based film.

[0008] In one achievable manner, the thickness of the expanded polytetrafluoroethylene-based film is 2 to 20 microns, the diameter of the conductive fiber is 1 to 20 microns, and the length of the conductive fiber is 1 to 10 mm.

[0009] In one achievable manner, the conductive fibers are chopped carbon fibers or metal fibers.

[0010] In one feasible manner, the expanded polytetrafluoroethylene conductive sealing plate includes a plurality of expanded polytetrafluoroethylene conductive film layers, which are stacked along the thickness direction; the expanded polytetrafluoroethylene based films of each two adjacent expanded polytetrafluoroethylene conductive film layers are connected to each other, and the conductive surface layers of each two adjacent expanded polytetrafluoroethylene conductive film layers are in contact with each other.

[0011] In one feasible manner, in each of the expanded polytetrafluoroethylene conductive film layers, there is a gap between the protruding parts of the plurality of conductive fibers, so that a gap is formed at the position of the conductive surface layer corresponding to the gap; the expanded polytetrafluoroethylene films of each two adjacent expanded polytetrafluoroethylene conductive film layers are in contact and bonded together through the gap.

[0012] In one achievable manner, the expanded polytetrafluoroethylene films of each two adjacent expanded polytetrafluoroethylene conductive film layers are bonded together after being sintered and melted.

[0013] The present invention also provides a method for manufacturing an expanded polytetrafluoroethylene conductive sealing plate, which is used to manufacture the expanded polytetrafluoroethylene conductive sealing plate. The expanded polytetrafluoroethylene conductive sealing plate includes at least one expanded polytetrafluoroethylene conductive film layer. The method for manufacturing the expanded polytetrafluoroethylene conductive sealing plate includes the following steps:

[0014] S10: providing an expanded polytetrafluoroethylene (EPF) film, and placing a spraying device loaded with a plurality of conductive fibers on one side of the expanded polytetrafluoroethylene (EPF) film; spraying the plurality of conductive fibers onto the expanded polytetrafluoroethylene (EPF) film using the spraying device, such that the conductive fibers penetrate the expanded polytetrafluoroethylene (EPF) film, and opposite ends of the conductive fibers extend to opposite sides of the expanded polytetrafluoroethylene (EPF) film, respectively;

[0015] S20: Rolling the expanded polytetrafluoroethylene (EPF) based membrane so that the portions of the plurality of conductive fibers extending to the opposite sides of the expanded polytetrafluoroethylene (EPF) based membrane are pressed down and overlapped with each other, so as to form conductive surface layers on the opposite sides of the expanded polytetrafluoroethylene (EPF) based membrane, thereby obtaining the expanded polytetrafluoroethylene (EPF) conductive film layer; wherein, the portion of the conductive fiber located in the expanded polytetrafluoroethylene (EPF) based membrane is the penetration portion, and the portion of the conductive fiber extending to the opposite sides of the expanded polytetrafluoroethylene (EPF) based membrane and being pressed down is the extension portion.

[0016] In one achievable manner, the expanded polytetrafluoroethylene conductive sealing plate comprises a plurality of expanded polytetrafluoroethylene conductive film layers; and the method for manufacturing the expanded polytetrafluoroethylene conductive sealing plate further comprises the following steps:

[0017] S30: stacking the plurality of expanded polytetrafluoroethylene conductive film layers together along their thickness direction, with the conductive surface layers of each adjacent two expanded polytetrafluoroethylene conductive film layers in contact with each other; simultaneously, gaps are formed between the protruding portions of the plurality of conductive fibers in each expanded polytetrafluoroethylene conductive film layer, and voids are formed in the conductive surface layers at positions corresponding to the gaps, with the expanded polytetrafluoroethylene films of each adjacent two expanded polytetrafluoroethylene conductive film layers in contact with each other through the gaps;

[0018] S40: sintering the plurality of expanded polytetrafluoroethylene conductive film layers at a certain temperature, so that the expanded polytetrafluoroethylene films of adjacent expanded polytetrafluoroethylene conductive film layers are melted and then bonded together.

[0019] In one feasible manner, in the above step S10, when the conductive fiber is ejected from the ejection device, the length direction of the conductive fiber is parallel to the thickness direction of the expanded polytetrafluoroethylene-based film, and the conductive fiber is ejected from the ejection device at a speed of 5 to 80 m / s.

[0020] The expanded polytetrafluoroethylene conductive sealing plate provided by the present invention is provided with a plurality of conductive fibers, each conductive fiber penetrates the expanded polytetrafluoroethylene based film, the portion of each conductive fiber located in the expanded polytetrafluoroethylene based film is a penetration portion, and the portion of each conductive fiber extending to the opposite sides of the expanded polytetrafluoroethylene based film is an extension portion. The extension portions of the plurality of conductive fibers are overlapped with each other after being bent obliquely to form conductive surface layers on the opposite sides of the expanded polytetrafluoroethylene based film; the conductive surface layers on the opposite sides are connected together by the penetration portions of each conductive fiber, thereby achieving the effect of overall conductivity of the expanded polytetrafluoroethylene conductive film layer, so that it has good conductive properties. At the same time, the expanded polytetrafluoroethylene conductive film layer has a stable structure, and the conductive surface layer is not easily separated from the expanded polytetrafluoroethylene based film. The expanded polytetrafluoroethylene conductive sealing plate not only has the advantages of expanded polytetrafluoroethylene such as light weight, high and low temperature resistance, and good sealing performance, but also has good conductivity and a stable and reliable structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 4 is a side view of an expanded polytetrafluoroethylene conductive sealing plate in an embodiment of the present invention.

[0022] Figure 2 for Figure 1 Schematic cross-section of .

[0023] Figure 3 for Figure 1 Schematic diagram of the planar structure.

[0024] Figure 4 for Figure 1 Side view of a single expanded polytetrafluoroethylene conductive film layer.

[0025] Figure 5 for Figure 4 Schematic cross-section of .

[0026] Figure 6 for Figure 5 Cross-sectional diagram of a single conductive fiber disposed on an expanded polytetrafluoroethylene-based membrane.

[0027] Figures 7 to 12b Schematic diagram of the manufacturing process of the expanded polytetrafluoroethylene conductive sealing plate in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0029] The terms "first," "second," "third," "fourth," and the like (if any) in the description and claims of the present invention are used to distinguish similar objects and are not necessarily used to describe a particular sequential order or sequence.

[0030] The directional terms "up," "down," "left," "right," "front," "back," "top," and "bottom" (if any) used in the specification and claims of the present invention are defined by the positions of the structures in the drawings and the positions of the structures relative to each other, and are intended only for clarity and convenience in expressing the technical solution. It should be understood that the use of directional terms should not limit the scope of protection claimed in the present invention.

[0031] like Figures 1 to 6 As shown, an expanded polytetrafluoroethylene (EPFE) conductive sealing plate provided in an embodiment of the present invention includes at least one expanded polytetrafluoroethylene (EPFE) conductive film layer 1. The expanded polytetrafluoroethylene (EPFE) conductive film layer 1 includes an expanded polytetrafluoroethylene (EPFE) based film 11 (i.e., an expanded polytetrafluoroethylene (EPFE) film, which can be made by stretching a EPFE resin through a special processing method) and a plurality of conductive fibers 12 spaced apart on the expanded polytetrafluoroethylene (EPFE) based film 11. Each conductive fiber 12 penetrates the expanded polytetrafluoroethylene (EPFE) based film 11 in the thickness direction T of the expanded polytetrafluoroethylene (EPFE) based film 11. Each conductive fiber 12 includes a penetration portion 121 and extension portions 122 connected to opposite ends of the penetration portion 121 (the penetration portion 121 and the extension portions 122 at the opposite ends are integrally formed). The penetration portion 121 is located within the expanded polytetrafluoroethylene (EPFE) based film 11, and the extension portions 122 at the opposite ends are located on opposite sides of the expanded polytetrafluoroethylene (EPFE) based film 11, respectively. In each conductive fiber 12 , the protruding portion 122 at each end is bent obliquely compared to the penetrating portion 121 , and the protruding portions 122 of multiple conductive fibers 12 overlap each other to form conductive surface layers 10 on opposite sides of the expanded polytetrafluoroethylene film 11 .

[0032] Specifically, the opposite ends of each conductive fiber 12 are respectively a first end and a second end. The protruding portions 122 of the first ends of the multiple conductive fibers 12 are overlapped with each other after being bent obliquely, thereby forming a conductive surface layer 10 on one side of the expanded polytetrafluoroethylene-based film 11; the protruding portions 122 of the second ends of the multiple conductive fibers 12 are overlapped with each other after being bent obliquely, thereby forming a conductive surface layer 10 on the other side of the expanded polytetrafluoroethylene-based film 11.

[0033] In each expanded polytetrafluoroethylene (EPFE) conductive film layer 1, a plurality of conductive fibers 12 are densely distributed on the expanded polytetrafluoroethylene (EPFE) film 11, and the conductive surface layer 10 is formed by the extensions 122 of adjacent conductive fibers 12 overlapping each other. Adjacent conductive fibers 12 include: adjacent conductive fibers 12 and non-adjacent but adjacent conductive fibers 12. Any fibers that can overlap together are sufficient (i.e., the conductive surface layer 10 is formed by the extensions 122 of adjacent conductive fibers 12 and / or the extensions 122 of non-adjacent but adjacent conductive fibers 12 overlapping each other). Because the extensions 122 have a certain length and the conductive fibers 12 are densely distributed on the expanded polytetrafluoroethylene (EPFE) film 11, when the extensions 122 are bent obliquely, they can overlap with nearby extensions 122, thereby forming a conductive surface layer 10 with a conductive network structure on the surface of the expanded polytetrafluoroethylene (EPFE) film 11.

[0034] The expanded polytetrafluoroethylene conductive sealing plate provided in this embodiment is provided with multiple conductive fibers 12, each conductive fiber 12 penetrates the expanded polytetrafluoroethylene based film 11, the portion of each conductive fiber 12 located within the expanded polytetrafluoroethylene based film 11 is a penetration portion 121, and the portion of each conductive fiber 12 extending to opposite sides of the expanded polytetrafluoroethylene based film 11 is an extension portion 122. The extension portions 122 of the multiple conductive fibers 12 are overlapped with each other after being bent obliquely to form conductive surface layers 10 on opposite sides of the expanded polytetrafluoroethylene based film 11; the conductive surface layers 10 on opposite sides are connected together by the penetration portions 121 of each conductive fiber 12, thereby achieving the overall conductive effect of the expanded polytetrafluoroethylene conductive film layer 1 (not only the surface is conductive, but both sides of the expanded polytetrafluoroethylene conductive film layer 1 and the space between the two sides of the expanded polytetrafluoroethylene conductive film layer 1 are conductive), so that it has good conductive properties. At the same time, the expanded polytetrafluoroethylene conductive film layer 1 has a stable structure, and the conductive surface layer 10 is not easily separated from the expanded polytetrafluoroethylene based film 11 (because the conductive fibers 12 penetrate the expanded polytetrafluoroethylene based film 11, the conductive surface layer 10 is firmly connected to the expanded polytetrafluoroethylene based film 11 through the penetration portion 121 of each conductive fiber 12, so it is not easy to separate). This expanded polytetrafluoroethylene conductive sealing plate not only has the advantages of expanded polytetrafluoroethylene such as light weight, high and low temperature resistance, and good sealing performance, but also has good conductivity and a stable and reliable structure. At the same time, this expanded polytetrafluoroethylene conductive sealing plate also has good air permeability (the expanded polytetrafluoroethylene based film 11 has multiple micropores, and the method of arranging the conductive fibers 12 on the expanded polytetrafluoroethylene based film 11 does not block the micropores, thereby maintaining the original air permeability of the expanded polytetrafluoroethylene based film 11).

[0035] As an embodiment, in each expanded polytetrafluoroethylene conductive film layer 1, the distribution density of the conductive fibers 12 on the expanded polytetrafluoroethylene based film 11 (i.e., the number of conductive fibers 12 per unit area of the expanded polytetrafluoroethylene based film 11) can be determined according to the conductivity requirements of the expanded polytetrafluoroethylene conductive film layer 1 (it is easy to understand that when the material, thickness, length and other characteristics of the conductive fibers 12 are constant, when the distribution density of the conductive fibers 12 is greater, the conductivity of the expanded polytetrafluoroethylene conductive film layer 1 is better and the conductivity is higher; when the distribution density of the conductive fibers 12 is smaller, the conductivity of the expanded polytetrafluoroethylene conductive film layer 1 is weaker and the conductivity is lower).

[0036] Preferably, in each expanded polytetrafluoroethylene (EPFE) conductive film layer 1, the plurality of conductive fibers 12 are arranged substantially uniformly and orderly on the expanded polytetrafluoroethylene (EPFE) based film 11, so that the conductivity of each portion of the expanded polytetrafluoroethylene (EPFE) conductive film layer 1 is consistent. Of course, in other embodiments, based on specific needs, the plurality of conductive fibers 12 may be arranged unevenly on the expanded polytetrafluoroethylene (EPFE) based film 11, so that the conductivity of each portion of the expanded polytetrafluoroethylene (EPFE) conductive film layer 1 is inconsistent.

[0037] Preferably, the penetrating portion 121 of the conductive fiber 12 is substantially straight and arranged substantially vertically within the expanded polytetrafluoroethylene (EPFE) film 11 (i.e., the length of the penetrating portion 121 is substantially parallel to the thickness direction T of the expanded polytetrafluoroethylene (EPFE) film 11), so that the penetrating portion 121 can more smoothly penetrate the expanded polytetrafluoroethylene (EPFE) film 11. Of course, in other embodiments, the penetrating portion 121 may also be arranged obliquely within the expanded polytetrafluoroethylene (EPFE) film 11 (i.e., the length of the penetrating portion 121 forms a certain angle with the thickness direction T of the expanded polytetrafluoroethylene (EPFE) film 11, wherein the angle is greater than 0° and less than 90°).

[0038] As an embodiment, in each expanded polytetrafluoroethylene conductive film layer 1, the inclined bending direction of the protruding portion 122 of the multiple conductive fibers 12 can be any direction (that is, the protruding portion 122 can tilt in any direction when tilted and bent, and the tilting direction of the protruding portion 122 of each conductive fiber 12 is not necessarily consistent. This is because in the actual production process, after the conductive fiber 12 passes through the expanded polytetrafluoroethylene based film 11, the two ends of the conductive fiber 12 may bend to a certain extent, and the bending direction is not certain, so the tilting direction of the protruding portion 122 in the subsequent rolling process is also not certain).

[0039] like Figures 4 to 6 As shown, as an embodiment, the extension portion 122 is bent and abutted against the surface of the expanded polytetrafluoroethylene based film 11, so that the conductive surface layer 10 is in contact with the surface of the expanded polytetrafluoroethylene based film 11 (i.e., the conductive surface layer 10 is abutted against the surface of the expanded polytetrafluoroethylene based film 11).

[0040] As an embodiment, the thickness of the expanded polytetrafluoroethylene based film 11 is 2 to 20 microns, the diameter of the conductive fiber 12 is 1 to 20 microns, and the length of the conductive fiber 12 is 1 to 10 mm, so that the conductive fiber 12 can more smoothly penetrate the expanded polytetrafluoroethylene based film 11 and make the expanded polytetrafluoroethylene conductive film layer 1 have good conductivity.

[0041] Preferably, the thickness of the expanded polytetrafluoroethylene-based film 11 is 3 to 10 microns, the diameter of the conductive fiber 12 is 5 to 10 microns, and the length of the conductive fiber 12 is 2 to 5 mm.

[0042] As an embodiment, the conductive fibers 12 are chopped carbon fibers or metal fibers, wherein the metal fibers can be copper fibers, iron fibers, silver fibers, aluminum fibers, gold fibers, etc.

[0043] like Figure 1 and Figure 2 As shown, as an embodiment, the expanded polytetrafluoroethylene conductive sealing plate includes a plurality of expanded polytetrafluoroethylene conductive film layers 1 (shown as a four-layer structure in the figure), and the plurality of expanded polytetrafluoroethylene conductive film layers 1 are stacked along the thickness direction T. The expanded polytetrafluoroethylene based films 11 of each adjacent two expanded polytetrafluoroethylene conductive film layers 1 are interconnected (i.e., the lower surface of the expanded polytetrafluoroethylene based film 11 of the expanded polytetrafluoroethylene conductive film layer 1 located above is interconnected with the upper surface of the expanded polytetrafluoroethylene based film 11 of the expanded polytetrafluoroethylene conductive film layer 1 located below), and the conductive surface layers 10 of each two adjacent expanded polytetrafluoroethylene conductive film layers 1 are in contact with each other (i.e., the conductive surface layer 10 on the lower side of the expanded polytetrafluoroethylene conductive film layer 1 located above is in contact with the conductive surface layer 10 on the upper side of the expanded polytetrafluoroethylene conductive film layer 1 located below), thereby fixing the plurality of expanded polytetrafluoroethylene conductive film layers 1 together and achieving overall conductivity of the expanded polytetrafluoroethylene conductive sealing plate. Of course, in other embodiments, the expanded polytetrafluoroethylene conductive sealing plate may also be a single-layer expanded polytetrafluoroethylene conductive film layer 1 .

[0044] like Figures 1 to 3 As shown, as an embodiment, in each expanded polytetrafluoroethylene conductive film layer 1, there are gaps between the protruding portions 122 of the plurality of conductive fibers 12, so that the conductive surface layer 10 forms a plurality of gaps 100 (such as Figure 3As shown, because the conductive fibers 12 are relatively thin and have a certain distribution density, the protruding portions 122 of the multiple conductive fibers 12 form gaps after being overlapped, thereby forming gaps 100 in the conductive surface layer 10 (i.e., the conductive surface layer 10 has a mesh structure). In other words, the conductive surface layer 10 does not completely cover the surface of the expanded polytetrafluoroethylene (EPFE)-based film 11, and the surface of the expanded polytetrafluoroethylene (EPFE)-based film 11 is exposed through the gaps 100. The expanded polytetrafluoroethylene (EPFE)-based films 11 of each adjacent expanded polytetrafluoroethylene (EPFE) conductive film layer 1 are in contact and bonded to each other through the gaps 100.

[0045] As an embodiment, the expanded polytetrafluoroethylene vinyl film 11 of each two adjacent expanded polytetrafluoroethylene conductive film layers 1 are bonded together after sintering and melting (when the expanded polytetrafluoroethylene conductive film layer 1 is sintered, the sintering temperature is greater than the melting temperature of the expanded polytetrafluoroethylene vinyl film 11, so that the expanded polytetrafluoroethylene vinyl film 11 melts, and after melting, the expanded polytetrafluoroethylene vinyl film 11 of the two adjacent expanded polytetrafluoroethylene conductive film layers 1 are bonded together through the gap 100 on the conductive surface layer 10, and can be compounded after cooling).

[0046] In one embodiment, conductive fibers 12 are sprayed onto an expanded polytetrafluoroethylene (EPF)-based film 11, forming a structure similar to a conductive fiber brush. The expanded polytetrafluoroethylene (EPF)-based film 11 with the inserted conductive fibers 12 is then rolled using a rolling device to flatten the portions of conductive fibers 12 extending from opposite sides of the expanded polytetrafluoroethylene (EPF)-based film 11, forming an expanded polytetrafluoroethylene (EPF) conductive film layer 1. Multiple expanded polytetrafluoroethylene (EPF) conductive film layers 1 are then stacked and sintered into a sheet, resulting in a fully conductive expanded polytetrafluoroethylene (EPF) conductive sealing sheet.

[0047] like Figures 7 to 12b As shown, the embodiment of the present invention also provides a method for manufacturing an expanded polytetrafluoroethylene conductive sealing plate, which is used to manufacture the expanded polytetrafluoroethylene conductive sealing plate. The expanded polytetrafluoroethylene conductive sealing plate includes at least one expanded polytetrafluoroethylene conductive film layer 1; the method for manufacturing the expanded polytetrafluoroethylene conductive sealing plate includes the following steps:

[0048] S10: Figures 7 to 8cAs shown, an expanded polytetrafluoroethylene-based film 11 is provided, and a spraying device 2 equipped with multiple conductive fibers 12 is placed on one side of the expanded polytetrafluoroethylene-based film 11; the spraying device 2 is used to densely spray multiple conductive fibers 12 onto the expanded polytetrafluoroethylene-based film 11, so that the conductive fibers 12 penetrate the expanded polytetrafluoroethylene-based film 11, and the opposite ends of the conductive fibers 12 extend to the opposite sides of the expanded polytetrafluoroethylene-based film 11, that is, a "fiber grass" structure is formed on the opposite sides of the expanded polytetrafluoroethylene-based film 11 (specifically, when spraying the conductive fibers 12, the spraying device 2 can spray the conductive fibers 12 onto the expanded polytetrafluoroethylene-based film 11 while moving along the S1 direction to spray the conductive fibers 12 to different positions on the expanded polytetrafluoroethylene-based film 11). Figure 7 It is a side view of the spraying device 2 before spraying the conductive fiber 12 onto the expanded polytetrafluoroethylene-based film 11; Figure 8a This is a side view of a plurality of conductive fibers 12 sprayed onto an expanded polytetrafluoroethylene film 11. Figure 8b for Figure 8a Schematic cross-section diagram, Figure 8c for Figure 8a Schematic diagram of the planar structure.

[0049] S20: Figures 9 to 10c As shown, the expanded polytetrafluoroethylene based film 11 is rolled by a rolling device 3, so that the parts of the plurality of conductive fibers 12 extending to the opposite sides of the expanded polytetrafluoroethylene based film 11 are pressed down and overlapped with each other (specifically, the rolling device 3 includes an upper roller and a lower roller, and the upper roller and the lower roller can be made of hardened rubber. During rolling, the expanded polytetrafluoroethylene based film 11 moves along the S2 direction, and the upper and lower ends of the conductive fibers 12 are pressed down when the expanded polytetrafluoroethylene based film 11 passes through the rolling device 3), so as to form conductive surface layers 10 on the opposite sides of the expanded polytetrafluoroethylene based film 11, thereby obtaining an expanded polytetrafluoroethylene conductive film layer 1. Among them, the part of the conductive fiber 12 located in the expanded polytetrafluoroethylene based film 11 is the penetration part 121, and the part of the conductive fiber 12 extending to the opposite sides of the expanded polytetrafluoroethylene based film 11 and being pressed down is the extension part 122. Among them, Figure 9 A side view of the rolling device 3 when rolling the expanded polytetrafluoroethylene-based film 11; Figure 10a is a side view of the expanded polytetrafluoroethylene conductive film layer 1 formed after rolling. Figure 10b for Figure 10a Schematic cross-section diagram, Figure 10c for Figure 10a Schematic diagram of the planar structure.

[0050] As an embodiment, the expanded polytetrafluoroethylene conductive sealing plate includes a plurality of expanded polytetrafluoroethylene conductive film layers 1. After the above step S20, the method for manufacturing the expanded polytetrafluoroethylene conductive sealing plate further includes the following steps:

[0051] S30: Figure 11 As shown, according to the required thickness, under a certain pressure or a certain tension, multiple expanded polytetrafluoroethylene conductive film layers 1 are stacked together along their thickness direction T (that is, when stacking multiple expanded polytetrafluoroethylene conductive film layers 1, it is necessary to apply pressure to the multiple expanded polytetrafluoroethylene conductive film layers 1 so that adjacent expanded polytetrafluoroethylene conductive film layers 1 are in close contact; the pressure can be applied by squeezing the multiple expanded polytetrafluoroethylene conductive film layers 1 at a certain pressure, or by winding the multiple expanded polytetrafluoroethylene conductive film layers 1 on a reel at a certain tension). The conductive surface layers 10 of each two adjacent expanded polytetrafluoroethylene conductive film layers 1 are in contact with each other; at the same time, there is a gap between the protruding portions 122 of the multiple conductive fibers 12 in each expanded polytetrafluoroethylene conductive film layer 1, and a gap 100 is formed at the position of the conductive surface layer 10 corresponding to the gap, and the expanded polytetrafluoroethylene film 11 of each two adjacent expanded polytetrafluoroethylene conductive film layers 1 are in contact with each other through the gap 100. Among them, Figure 11 It is a schematic structural diagram of multiple expanded polytetrafluoroethylene conductive film layers 1 when they are stacked.

[0052] S40: Figure 12a and Figure 12b As shown, multiple expanded polytetrafluoroethylene conductive film layers 1 are sintered at a certain temperature (the sintering temperature is greater than the melting temperature of the expanded polytetrafluoroethylene film 11, for example, the sintering temperature is 347°C to 390°C), so that the expanded polytetrafluoroethylene film 11 of adjacent expanded polytetrafluoroethylene conductive film layers 1 are melted and bonded together; at the same time, the conductive surface layer 10 located inside is buried in the expanded polytetrafluoroethylene film 11, thus obtaining an expanded polytetrafluoroethylene conductive sealing plate with a multi-layer expanded polytetrafluoroethylene conductive film layer 1 structure. Figure 12a It is a side view of multiple expanded polytetrafluoroethylene conductive film layers 1 after sintering. Figure 12b for Figure 12a Schematic cross-section of .

[0053] As an embodiment, in step S10, the spraying device 2 is a spray gun. The spraying device 2 can be placed below the expanded polytetrafluoroethylene film 11, in which case the spraying device 2 sprays the conductive fibers 12 upward; the spraying device 2 can also be placed above the expanded polytetrafluoroethylene film 11, in which case the spraying device 2 sprays the conductive fibers 12 downward.

[0054] As an embodiment, in step S10, when the conductive fibers 12 are ejected from the ejection device 2, the length direction of the conductive fibers 12 is parallel to the thickness direction T of the expanded polytetrafluoroethylene (EPF) film 11. The conductive fibers 12 are ejected from the ejection device 2 at a velocity of 5 to 80 m / s, so that the conductive fibers 12 can more smoothly penetrate the expanded polytetrafluoroethylene (EPF) film 11 and prevent the conductive fibers 12 from completely passing through the expanded polytetrafluoroethylene (EPF) film 11 and then detaching from the expanded polytetrafluoroethylene (EPF) film 11. (If the ejection velocity is too high, the conductive fibers 12 may completely penetrate the expanded polytetrafluoroethylene (EPF) film 11 and then detach from the expanded polytetrafluoroethylene (EPF) film 11.) Preferably, the velocity of the conductive fibers 12 ejected from the ejection device 2 is 20 to 50 m / s.

[0055] As an embodiment, in the above-mentioned step S20, after the expanded polytetrafluoroethylene based film 11 is rolled, the portions of the conductive fibers 12 extending to the opposite sides of the expanded polytetrafluoroethylene based film 11 are pressed to fit the surface of the expanded polytetrafluoroethylene based film 11, that is, the extending portions 122 of the conductive fibers 12 are in contact with the surface of the expanded polytetrafluoroethylene based film 11, thereby making the conductive surface layer 10 fit the surface of the expanded polytetrafluoroethylene based film 11.

[0056] The expanded polytetrafluoroethylene conductive sealing plate provided in an embodiment of the present invention is provided with multiple conductive fibers 12, each conductive fiber 12 penetrates the expanded polytetrafluoroethylene based film 11, the portion of each conductive fiber 12 located in the expanded polytetrafluoroethylene based film 11 is a penetration portion 121, and the portion of each conductive fiber 12 extending to the opposite sides of the expanded polytetrafluoroethylene based film 11 is an extension portion 122. The extension portions 122 of the multiple conductive fibers 12 are overlapped with each other after being bent obliquely to form conductive surface layers 10 on opposite sides of the expanded polytetrafluoroethylene based film 11; the conductive surface layers 10 on opposite sides are connected together by the penetration portions 121 of each conductive fiber 12, thereby achieving the overall conductive effect of the expanded polytetrafluoroethylene conductive film layer 1 (not only the surface is conductive, but both sides of the expanded polytetrafluoroethylene conductive film layer 1 and between the two sides of the expanded polytetrafluoroethylene conductive film layer 1 are conductive), so that it has good conductive properties. At the same time, the expanded polytetrafluoroethylene conductive film layer 1 has a stable structure, and the conductive surface layer 10 is not easily separated from the expanded polytetrafluoroethylene based film 11 (because the conductive fibers 12 penetrate the expanded polytetrafluoroethylene based film 11, the conductive surface layer 10 is firmly connected to the expanded polytetrafluoroethylene based film 11 through the penetration portion 121 of each conductive fiber 12, so it is not easy to separate). This expanded polytetrafluoroethylene conductive sealing plate not only has the advantages of expanded polytetrafluoroethylene such as light weight, high and low temperature resistance, and good sealing performance, but also has good conductivity and a stable and reliable structure. At the same time, this expanded polytetrafluoroethylene conductive sealing plate also has good air permeability (the expanded polytetrafluoroethylene based film 11 has multiple micropores, and the method of arranging the conductive fibers 12 on the expanded polytetrafluoroethylene based film 11 does not block the micropores, thereby maintaining the original air permeability of the expanded polytetrafluoroethylene based film 11).

[0057] Example 1

[0058] A spray gun loaded with chopped conductive fibers was placed beneath an expanded polytetrafluoroethylene (EPFE) film. Copper fibers, 6 microns in diameter and 4 mm in length, were sprayed onto the 4-micron-thick EPFE film at a velocity of 45 m / s. During spraying, the conductive fibers were aligned parallel to the film's thickness, piercing the film and forming a "fiber grass" pattern on both sides. The film with the conductive "fiber grass" was then passed over a hardened rubber pressure roller, which flattened the "fiber grass" and caused the fibers to overlap on the upper and lower surfaces of the film, forming a conductive interpenetrating network.

[0059] The films are then stacked layer by layer to the desired thickness and sintered at 380°C for 6 hours under a certain pressure or tension, so that the expanded polytetrafluoroethylene layers in different layers are bonded together, ultimately forming a conductive expanded polytetrafluoroethylene sealing material with an interpenetrating conductive network structure. The conductive expanded polytetrafluoroethylene sealing material was tested and its conductivity was 5.6×10 5 S / m.

[0060] Example 2

[0061] A spray gun loaded with chopped conductive fibers was placed beneath an expanded polytetrafluoroethylene (EPFE) film. Carbon fibers, 6 microns in diameter and 6 mm in length, were sprayed onto the 7-micron-thick EPFE film at a spray velocity of 30 m / s. During spraying, the conductive fibers were aligned parallel to the film's thickness, piercing the film and forming a "fiber grass"-like structure on both sides. The film with the conductive "fiber grass" was then passed over a hardened rubber pressure roller, which flattened the "fiber grass" and caused the fibers to overlap on the upper and lower surfaces of the film, forming a conductive interpenetrating network.

[0062] The films are then stacked layer by layer to the desired thickness and sintered at 370°C for 8 hours under a certain pressure or tension, so that the expanded polytetrafluoroethylene layers in different layers are bonded together, ultimately forming a conductive expanded polytetrafluoroethylene sealing material with an interpenetrating conductive network structure. The conductive expanded polytetrafluoroethylene sealing material was tested and its conductivity was 8.1×10 3 S / m.

[0063] Example 3

[0064] A spray gun loaded with chopped conductive fibers was placed beneath an expanded polytetrafluoroethylene (EPFE) film. Carbon fibers, 2 microns in diameter and 5 mm in length, were sprayed onto the 10-micron-thick EPFE film at a spray velocity of 15 m / s. During spraying, the conductive fibers were aligned parallel to the film's thickness, piercing the film and forming a "fiber grass"-like structure on both sides. The film with the conductive "fiber grass" was then passed over a hardened rubber pressure roller, which flattened the "fiber grass" and caused the fibers to overlap on the upper and lower surfaces of the film, forming a conductive interpenetrating network.

[0065] The films are then stacked layer by layer to the desired thickness and sintered at 385°C for 3 hours under a certain pressure or tension, so that the expanded polytetrafluoroethylene layers in different layers adhere to each other, ultimately forming a conductive expanded polytetrafluoroethylene sealing material with an interpenetrating conductive network structure. The conductive expanded polytetrafluoroethylene sealing material was tested and its conductivity was 4.3×10 6 S / m.

[0066] Example 4

[0067] A spray gun loaded with chopped conductive fibers was placed beneath an expanded polytetrafluoroethylene (EPFE) film. Carbon fibers, 3 microns in diameter and 6 mm in length, were sprayed onto the 7-micron-thick EPFE film at a spray velocity of 20 m / s. During spraying, the conductive fibers were aligned parallel to the film's thickness, piercing the film and forming a "fiber grass" pattern on both sides. The film with the conductive "fiber grass" was then passed over a hardened rubber pressure roller, which flattened the "fiber grass" and caused the fibers to overlap on the upper and lower surfaces of the film, forming a conductive interpenetrating network.

[0068] The films are then stacked layer by layer to the desired thickness and sintered at 380°C for 8 hours under a certain pressure or tension, so that the expanded polytetrafluoroethylene layers in different layers adhere to each other, ultimately forming a conductive expanded polytetrafluoroethylene sealing material with an interpenetrating conductive network structure. The conductive expanded polytetrafluoroethylene sealing material was tested and its conductivity was 1.3×10 2 S / m.

[0069] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An expanded polytetrafluoroethylene conductive sealing plate, characterized in that: The invention comprises at least one expanded polytetrafluoroethylene (EPFE) conductive film layer, wherein the expanded polytetrafluoroethylene (EPFE) conductive film layer comprises an expanded polytetrafluoroethylene (EPFE) based film and a plurality of conductive fibers spaced apart on the expanded polytetrafluoroethylene (EPFE) based film; each conductive fiber penetrates the expanded polytetrafluoroethylene (EPFE) based film along the thickness direction of the expanded polytetrafluoroethylene (EPFE) based film, and each conductive fiber comprises a penetration portion and protrusion portions connected to opposite ends of the penetration portion; the penetration portion is located in the expanded polytetrafluoroethylene (EPFE) based film, and the protrusion portions at opposite ends are respectively located on opposite sides of the expanded polytetrafluoroethylene (EPFE) based film; the protrusion portion at each end is inclined and bent relative to the penetration portion, and the protrusion portions of the plurality of conductive fibers overlap each other to form conductive surface layers on opposite sides of the expanded polytetrafluoroethylene (EPFE) based film.

2. The expanded polytetrafluoroethylene conductive sealing plate according to claim 1, characterized in that: The protruding portion is bent and abuts against the surface of the expanded polytetrafluoroethylene film, so that the conductive surface layer is in contact with the surface of the expanded polytetrafluoroethylene film.

3. The expanded polytetrafluoroethylene conductive sealing plate according to claim 1, characterized in that: The thickness of the expanded polytetrafluoroethylene-based film is 2 to 20 microns, the diameter of the conductive fiber is 1 to 20 microns, and the length of the conductive fiber is 1 to 10 mm.

4. The expanded polytetrafluoroethylene conductive sealing plate according to claim 1, characterized in that: The conductive fibers are chopped carbon fibers or metal fibers.

5. The expanded polytetrafluoroethylene conductive sealing plate according to any one of claims 1 to 4, characterized in that: The expanded polytetrafluoroethylene conductive sealing plate includes a plurality of expanded polytetrafluoroethylene conductive film layers, which are stacked along the thickness direction; the expanded polytetrafluoroethylene conductive film layers of each adjacent two expanded polytetrafluoroethylene conductive film layers are connected to each other, and the conductive surface layers of each adjacent two expanded polytetrafluoroethylene conductive film layers are in contact with each other.

6. The expanded polytetrafluoroethylene conductive sealing plate according to claim 5, characterized in that: In each of the expanded polytetrafluoroethylene conductive film layers, there are gaps between the protruding portions of the plurality of conductive fibers, so that gaps are formed in the conductive surface layer at positions corresponding to the gaps; the expanded polytetrafluoroethylene films of each two adjacent expanded polytetrafluoroethylene conductive film layers are in contact and bonded together through the gaps.

7. The expanded polytetrafluoroethylene conductive sealing plate according to claim 6, characterized in that: The expanded polytetrafluoroethylene films of each two adjacent expanded polytetrafluoroethylene conductive film layers are bonded together after being sintered and melted.

8. A method for manufacturing an expanded polytetrafluoroethylene conductive sealing plate, characterized in that: Used to manufacture the expanded polytetrafluoroethylene conductive sealing plate according to any one of claims 1 to 7, the expanded polytetrafluoroethylene conductive sealing plate comprises at least one expanded polytetrafluoroethylene conductive film layer; the manufacturing method of the expanded polytetrafluoroethylene conductive sealing plate comprises the following steps: S10: providing an expanded polytetrafluoroethylene (EPF) film, and placing a spraying device loaded with a plurality of conductive fibers on one side of the expanded polytetrafluoroethylene (EPF) film; spraying the plurality of conductive fibers onto the expanded polytetrafluoroethylene (EPF) film using the spraying device, such that the conductive fibers penetrate the expanded polytetrafluoroethylene (EPF) film, and opposite ends of the conductive fibers extend to opposite sides of the expanded polytetrafluoroethylene (EPF) film, respectively; S20: Rolling the expanded polytetrafluoroethylene (EPF) based membrane so that the portions of the plurality of conductive fibers extending to the opposite sides of the expanded polytetrafluoroethylene (EPF) based membrane are pressed down and overlapped with each other, so as to form conductive surface layers on the opposite sides of the expanded polytetrafluoroethylene (EPF) based membrane, thereby obtaining the expanded polytetrafluoroethylene (EPF) conductive film layer; wherein, the portion of the conductive fiber located in the expanded polytetrafluoroethylene (EPF) based membrane is the penetration portion, and the portion of the conductive fiber extending to the opposite sides of the expanded polytetrafluoroethylene (EPF) based membrane and being pressed down is the extension portion.

9. The method for manufacturing an expanded polytetrafluoroethylene conductive sealing plate according to claim 8, wherein: The expanded polytetrafluoroethylene conductive sealing plate comprises a plurality of expanded polytetrafluoroethylene conductive film layers; the method for manufacturing the expanded polytetrafluoroethylene conductive sealing plate further comprises the following steps: S30: stacking the plurality of expanded polytetrafluoroethylene conductive film layers together along their thickness direction, with the conductive surface layers of each adjacent two expanded polytetrafluoroethylene conductive film layers in contact with each other; simultaneously, gaps are formed between the protruding portions of the plurality of conductive fibers in each expanded polytetrafluoroethylene conductive film layer, and voids are formed in the conductive surface layers at positions corresponding to the gaps, with the expanded polytetrafluoroethylene films of each adjacent two expanded polytetrafluoroethylene conductive film layers in contact with each other through the gaps; S40: sintering the plurality of expanded polytetrafluoroethylene conductive film layers at a certain temperature, so that the expanded polytetrafluoroethylene films of adjacent expanded polytetrafluoroethylene conductive film layers are melted and then bonded together.

10. The method for manufacturing an expanded polytetrafluoroethylene conductive sealing plate according to claim 8 or 9, characterized in that: In the above step S10, when the conductive fibers are ejected from the ejection device, the length direction of the conductive fibers is parallel to the thickness direction of the expanded polytetrafluoroethylene-based film; and the speed of the conductive fibers when ejected from the ejection device is 5 to 80 m / s.

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