Diaphragm slitting tool, diaphragm slitting device and slitting process

Abstract

The present application provides a diaphragm slitting tool, a diaphragm slitting device and a slitting process, which relate to the field of battery diaphragm production. The diaphragm slitting tool includes two cutting parts, each of which includes: a first cutting knife and a second cutting knife, the first cutting knife is located on the first side of the diaphragm and has a support surface for supporting the diaphragm, the second cutting knife is located on the second side of the diaphragm, the second cutting knife is a circular knife, and the second cutting knife is provided with an annular blade along its outer circumference, and the blade can keep in contact with the support surface after cutting the diaphragm. Among them, the blade is a single-sided blade or a double-sided blade, the edge angle of the single-sided blade is 30°-50°, and the edge angle of the double-sided blade is 60°-110°. By improving the edge angle of the blade of the second cutting knife and adjusting the friction resistance between the second cutting knife and the diaphragm, the technical problems of glue shedding and warping of the coated diaphragm during the slitting process can be effectively improved, and the qualified rate of the product after slitting can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery diaphragm production, and more specifically, to a diaphragm slitting tool, a diaphragm slitting device and a slitting process. Background Art

[0002] Lithium-ion batteries are currently widely used in many fields such as mobile phones, computers and electric vehicles due to their many advantages such as high voltage, large specific energy, wide operating temperature range, high specific power, stable discharge and long storage time. As battery voltage and capacity continue to increase, the safety risks of lithium batteries are also gradually increasing.

[0003] As one of the key materials of lithium-ion batteries, the separator has a great impact on the safety performance of the battery. The commercial separators are polyolefin separators, including high-density polyethylene (HDPE) and polypropylene (PP) separators. These two separators have low melting points, 130°C and 165°C respectively. In the case of overheating of the battery, these two separators are prone to melt shrinkage, causing a short circuit between the positive and negative electrodes, resulting in serious safety accidents such as battery explosion and fire.

[0004] The circular knife of the slitting machine used in the existing battery production, when it is necessary to cut the battery isolation membrane (referred to as isolation membrane or diaphragm), if the cutting object is a coated diaphragm, especially a polymer coated diaphragm, such as a coated diaphragm with a base film of PP or PET, etc., and a surface coated with a PVDF coating product, there will be glue peeling and warping, which affects the product qualification rate and product quality. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a diaphragm slitting tool, a diaphragm slitting device and a slitting process, which can improve the technical problems of glue peeling and edge warping of the coated diaphragm during the slitting process.

[0006] In a first aspect, an embodiment of the present application provides a diaphragm slitting tool, which includes two spaced-apart cutting portions for cutting off two end portions in a width direction of the diaphragm, wherein the diaphragm includes a first side and a second side along a thickness direction thereof.

[0007] Each cutting part includes: a first cutting knife and a second cutting knife. The first cutting knife is located on the first side of the diaphragm and has a supporting surface for supporting the diaphragm. The second cutting knife is located on the second side of the diaphragm. The second cutting knife is a circular knife. The second cutting knife is provided with an annular blade along its outer circumference. The blade can keep in contact with the supporting surface after cutting the diaphragm.

[0008] The blade is single-sided or double-sided, the edge angle of the single-sided blade is 30°-50°, and the edge angle of the double-sided blade is 60°-110°.

[0009] In the above implementation process, the blade angle of the second cutting knife is improved, and the friction resistance between the second cutting knife and the diaphragm is adjusted, thereby effectively improving the technical problems of glue peeling and edge warping of the coated diaphragm during the slitting process, thereby improving the qualified rate of the products after slitting.

[0010] In a possible embodiment, the edge angle of the double-sided edge is 100°-110°.

[0011] In the above implementation process, by further improving and limiting the edge angle of the double-sided blade, not only the technical problems of glue peeling and edge warping during the slitting process of the coated diaphragm are improved, but also the service life of the second cutting knife is taken into account, thereby reducing the production cost.

[0012] In a possible embodiment, the double-sided edge includes a first bevel and a second bevel connected to each other in the thickness direction of the second cutting blade, and the first bevel and the second bevel are symmetrically arranged along the center line of the second cutting blade.

[0013] In the above implementation process, the symmetrical arrangement makes the friction resistance between the first inclined surface and the second inclined surface and the diaphragm basically consistent, which is conducive to improving the warping and debonding problems. At this time, the double-sided edge can be a V-shaped flat edge or a V-shaped clam edge.

[0014] Optionally, the double-sided edge is a V-shaped flat edge.

[0015] Among them, the V-shaped flat blade setting makes its cutting sharper than clam blades, and the friction during the slitting process is smaller, thus avoiding the problems of warping and degumming caused by friction during the slitting process.

[0016] In a possible embodiment, the membrane cutting tool has a transmission mechanism, which is connected to the second cutting knife to drive the second cutting knife to rotate, wherein the movement direction of the contact side of the blade with the membrane is the same as the transmission direction of the membrane.

[0017] In the above implementation process, the friction between the blade and the contact side of the diaphragm is reduced, and the warping and debonding problems are further improved.

[0018] In a possible implementation manner, the edge angle of the single-sided cutting edge is 30°-45°.

[0019] In the above implementation process, the edge angle of the single-sided blade effectively improves the problems of edge warping and debonding.

[0020] In a second aspect, an embodiment of the present application provides a diaphragm slitting device, which includes an unwinding mechanism, a clamping mechanism, a flattening mechanism, the diaphragm slitting tool provided in the first aspect of the present application, and a winding mechanism arranged in sequence along the transmission direction of the diaphragm.

[0021] Among them, the clamping and conveying mechanism includes a first clamping roller, a second clamping roller and a third clamping roller which are arranged in sequence along the transmission direction of the diaphragm. The stroke of the diaphragm between the first clamping roller and the second clamping roller is smaller than the stroke of the diaphragm between the third clamping roller and the flattening mechanism, and the stroke of the diaphragm between the third clamping roller and the flattening mechanism is smaller than the stroke of the diaphragm between the second clamping roller and the third clamping roller.

[0022] In the above implementation process, three groups of spaced-apart clamping rollers are set between the unwinding mechanism and the flattening mechanism, which can make the rear end surface of the winding relatively flat and reduce the generation of slanted wrinkles on the product. The diaphragm slitting using diaphragm slitting tools can effectively improve the technical problems of glue peeling and warping of the coated diaphragm during the slitting process, thereby improving the qualified rate of the products after slitting.

[0023] In a third aspect, an embodiment of the present application provides a diaphragm slitting process performed based on the diaphragm slitting device provided in the second aspect of the present application, comprising:

[0024] The diaphragm is unrolled by the unwinding mechanism, exhausted by the clamping mechanism, flattened by the flattening mechanism, and then transported to the diaphragm slitting tool. The two end portions to be cut off in the width direction of the diaphragm are respectively located between the first cutting knife and the second cutting knife of the corresponding cutting part, and the blade of the second cutting knife is arranged perpendicular to the diaphragm so that the blade can keep contact with the supporting surface after vertically cutting the diaphragm, drive the second cutting knife to rotate, and obtain the finished product after cutting off the two end portions of the diaphragm, and the finished product is rolled up by the winding mechanism.

[0025] In the above implementation process, the diaphragm slitting performed by the diaphragm slitting device can effectively improve the technical problems of glue peeling and edge warping of the coated diaphragm during the slitting process, improve the qualified rate of the products after slitting, and at the same time has a certain effect on improving the problems of uneven rear end surface and slanted wrinkles of the product after winding.

[0026] In a possible implementation, when the diaphragm is unwound by the unwinding mechanism, the unwinding tension is controlled to be 60N±10N, and when the finished product is wound by the winding mechanism, the winding tension is controlled to be 0.09N / mm±0.03N / mm.

[0027] In the above implementation process, the control of the above parameters can improve the problem of uneven rear end surface and slanted wrinkles of the product after winding, and also improve the technical problems of glue loss and warping in the slitting process to a certain extent.

[0028] In one possible embodiment, the diaphragm includes a polymer coating layer and a base film, the polymer coating layer includes at least one of polyvinylidene fluoride homopolymer, a copolymer of polyvinylidene fluoride and hexafluoropropylene, a polyvinylidene fluoride-trichloroethylene copolymer, polyacrylonitrile, and polymethacrylate or its derivatives, and the base film includes polyethylene, polypropylene, polyethylene-polypropylene composite film or non-woven fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the structure of a diaphragm cutting device provided in an embodiment;

[0031] Figure 2 is a schematic structural diagram of two cutting parts including a second cutting knife 143a;

[0032] Figure 3 is a schematic structural diagram of two cutting parts including a second cutting knife 143b;

[0033] Figure 4 is a schematic structural diagram of the second cutting knife 143a;

[0034] Figure 5 Schematic diagram of the structure of the second cutting knife 143b.

[0035] Icons: 10-diaphragm slitting device; 100-frame; 110-unwinding mechanism; 121-first clamping roller; 123-second clamping roller; 125-third clamping roller; 130-flattening mechanism; 140-diaphragm slitting tool; 141-first cutting knife; 1411-support surface; 143a-second cutting knife; 143b-second cutting knife; 144-blade; 1441-first inclined surface; 1443-second inclined surface; 1445-cutting surface; 150-winding mechanism; 160-guide roller; 170-diaphragm. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0039] In the description of the present application, it should be noted that the terms "upper", "lower", "horizontal", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0040] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0041] Example 1

[0042] See also Figure 1 A membrane slitting device 10 includes a frame 100, and a reeling mechanism 110, a clamping mechanism, a flattening mechanism 130, a membrane slitting tool 140, and a reeling mechanism 150, which are arranged on the frame 100 and in sequence along the transmission direction of the membrane 170.

[0043] The unwinding mechanism 110 is used to unwind the wound diaphragm 170. The unwinding mechanism 110 can be unwound by upper unwinding or lower unwinding. In this embodiment, the upper unwinding method is adopted. The clamping mechanism is used to clamp the diaphragm 170 for exhaust. The flattening mechanism 130 is, for example, an arc-shaped flattening roller, which is used to flatten the diaphragm 170. The relative position of the flattening roller and the film is adjustable. The angle between the end surface of the flattening roller in contact with the film and the horizontal plane where the center of the flattening roller is located is 30-50°. Those skilled in the art can adjust it according to actual needs. The winding mechanism 150 is used to wind up the diaphragm 170 of corresponding width obtained after being cut by the diaphragm slitting tool 140. The specific settings of the unwinding mechanism 110, the clamping mechanism, the flattening mechanism 130 and the winding mechanism 150 can refer to the relevant technology and will not be repeated here.

[0044] A plurality of guide rollers 160 may be provided between the unwinding mechanism 110 and the flattening mechanism 130, and the guide rollers 160 are used to transport the diaphragm 170 to the flattening mechanism 130 along a preset direction. The number of guide rollers 160 is, for example, seven, and the clamping mechanism includes three groups of clamping rollers arranged in sequence along the transmission direction of the diaphragm 170, and the three groups of clamping rollers are sequentially arranged as the first clamping roller 121, the second clamping roller 123, and the third clamping roller 125 along the transmission direction of the diaphragm 170. No guide roller 160 is provided between the first clamping roller 121 and the unwinding mechanism 110, and the first clamping roller 123 is arranged as the third clamping roller 125. Two guide rollers 160 are arranged between the first clamping roller 121 and the second clamping roller 123, three guide rollers 160 are arranged between the second clamping roller 123 and the third clamping roller 125, and two guide rollers 160 are arranged between the third clamping roller 125 and the flattening roller, wherein the travel of the diaphragm 170 between the first clamping roller 121 and the second clamping roller 123 is shorter than the travel of the diaphragm 170 between the third clamping roller 125 and the flattening mechanism 130, and the travel of the diaphragm 170 between the third clamping roller 125 and the flattening mechanism 130 is shorter than the travel of the diaphragm 170 between the second clamping roller 123 and the third clamping roller 125. The above three groups of clamping rollers can avoid the problem of uneven surface and wrinkles at the rear end of winding to a certain extent.

[0045] See also Figure 2 as well as Figure 3 The diaphragm slitting tool 140 is used to cut off the two ends to be cut in the width direction of the diaphragm 170 and obtain a finished product of corresponding width. The width direction here is a direction that is roughly orthogonal to the transmission direction of the substrate diaphragm 170 and roughly parallel to the surface of the diaphragm 170.

[0046] Specifically, the membrane slitting tool 140 includes two cutting portions which are provided on the frame 100 and are arranged at intervals along the width direction of the membrane 170 , and the two cutting portions are used to cut off two ends of the membrane 170 in the width direction.

[0047] The diaphragm 170 includes a first side and a second side along the thickness direction thereof. According to actual usage habits, the first side is the lower side of the diaphragm 170 , and the second side is the upper side of the diaphragm 170 .

[0048] Each cutting portion includes a first cutting blade 141 and a second cutting blade 143a.

[0049] The first cutting knife 141 is located at a first side of the diaphragm 170 . The first cutting knife 141 has a supporting surface 1411 for supporting the diaphragm 170 . The supporting surface 1411 is used to guide the second cutting knife 143 a after cutting the diaphragm 170 .

[0050] The first cutting knife 141 may be a flat knife or a non-toothed circular knife.

[0051] In this embodiment, the first cutting knife 141 is a non-toothed circular knife, and the outer periphery of the first cutting knife 141 has an annular supporting surface 1411. In order to reduce friction, the first cutting knife 141 is rotatably arranged on the frame 100 to reduce the friction between the diaphragm 170 and it, wherein the first cutting knife 141 is arranged perpendicular to the diaphragm 170, and the movement direction of the contact side of the first cutting knife 141 and the diaphragm 170 is the same as the transmission direction of the diaphragm 170.

[0052] The second cutting knife 143a is located on the second side of the diaphragm 170. The second cutting knife 143a is a circular knife. The second cutting knife 143a is provided with an annular blade 144 along its outer circumference. The thickness of the blade 144 gradually decreases from the center of the second cutting knife 143a to the end away from the center of the second cutting knife 143a. The blade 144 is arranged vertically to the diaphragm 170 so that the blade 144 can vertically cut the diaphragm 170 and keep in contact with the support surface 1411.

[0053] The blade 144 is a double-sided blade or a single-sided blade.

[0054] In this embodiment, Figure 2 by Figure 4 As shown, when the blade 144 is a double-sided blade, the edge angle α of the double-sided blade is 60°-110°, for example, the edge angle α of the double-sided blade is 60°, 65°, 70°, 75°, 80°, 86°, 90°, 100° or 110°, etc.

[0055] The inventors have discovered that the service life of the second cutting knife 143a depends to a large extent on the service life of the blade 144. The smaller the cutting edge angle, the sharper it is, and less warping and glue loss are produced when cutting materials. However, the smaller the cutting edge angle, the shorter the service life of the blade 144. Therefore, how to balance the service life of the second cutting knife 143a and the cutting edge angle is a difficult point.

[0056] Based on the above findings, when the blade 144 of the second cutting knife 143a is a double-sided blade, the edge angle α of the double-sided blade is 100°-110°, for example, the edge angle α of the double-sided blade is 100°, 102°, 104°, 105°, 108° or 110°, etc. By adopting the above edge angle, the service life of the second cutting knife 143a can be taken into account while improving the problems of glue peeling and edge warping.

[0057] In order to ensure better improvement of glue peeling and edge warping, the double-sided blade includes a first bevel 1441 and a second bevel 1443 connected to each other in the thickness direction of the second cutting knife 143a, wherein the first bevel 1441 and the second bevel 1443 are symmetrically arranged along the center line of the second cutting knife 143a.

[0058] At this time, the cross-section of the first bevel 1441 and the second bevel 1443 along the thickness direction of the second cutting knife 143a can be a straight line (V-shaped flat blade), or an arc or a wave, etc., where the arc can be convex (such as a V-shaped clam blade) or concave.

[0059] like Figure 4 As shown, the double-sided blade is a V-shaped flat blade, which is easy to manufacture and has low friction during the slitting process, thereby avoiding edge warping and degumming problems caused by friction during the slitting process.

[0060] Optionally, the diaphragm cutting tool 140 has a transmission mechanism (not shown), which is connected to the second cutting knife 143a to drive the second cutting knife 143a to rotate, wherein the movement direction (tangential direction) of the contact side of the blade 144 with the diaphragm 170 is the same as the transmission direction of the diaphragm 170.

[0061] It should be noted that the rotation speed of the second cutting knife 143 a should be adapted to the transmission speed of the diaphragm 170 , that is, the tangential speed of the second cutting knife 143 a is substantially the same as the transmission speed of the diaphragm 170 .

[0062] like Figure 3 as well as Figure 5 As shown, in some optional embodiments provided in the present application, when the blade 144 of the second cutting knife 143b is a single-sided blade, the edge angle α of the single-sided blade is 30°-50°, for example, the edge angle α of the single-sided blade is 30°, 35°, 40°, 45° or 50°, etc.

[0063] Optionally, the edge angle α of the single-sided blade is 30°-45°. By limiting the edge angle, debonding and falling of the diaphragm 170 can be effectively avoided.

[0064] Among them, the single-sided blade is composed of any surface of the second cutting knife 143b in its thickness direction and the cutting surface 1445, wherein the cutting surface 1445 is an annular inclined surface with a straight cross-section. During actual use, the cutting surfaces 1445 of the two second cutting knives 143b face each other, that is, both face the middle of the diaphragm 170.

[0065] The present application also provides a diaphragm 170 slitting process based on the diaphragm slitting device 10, which includes:

[0066] The diaphragm 170 is unrolled by the unwinding mechanism 110, vented by the clamping mechanism, flattened by the flattening mechanism 130, and then conveyed to the diaphragm slitting tool 140. The two end portions to be cut off in the width direction of the diaphragm 170 are respectively located between the first cutting knife 141 and the second cutting knife 143a of the corresponding cutting part. The second cutting knife 143a is driven to rotate, and the two end portions of the diaphragm 170 are cut off to obtain the finished product, and the finished product is rolled up by the winding mechanism 150.

[0067] The product quality evaluation after winding not only involves glue loss and warping, but also involves evaluation indicators such as whether the end surface after winding is flat and whether wrinkles are generated. Based on this, optionally, when the diaphragm 170 is unwound through the unwinding mechanism 110, the unwinding tension is controlled to be 60N±10N, for example, the unwinding tension is 50N, 55N, 60N, 65N, 68N or 70N, etc., and when the finished diaphragm 170 is wound through the winding mechanism 150, the winding tension is controlled to be 0.09N / mm±0.03N / mm, for example, the winding tension is 0.06N / mm, 0.07N / mm, 0.08N / mm, 0.09N / mm, 0.1N / mm, 0.11N / mm or 0.12N / mm, etc., which effectively improves the flatness of the end surface after winding and avoids wrinkles, while alleviating the proportion of glue loss to a certain extent.

[0068] It should be noted that the diaphragm slitting device 10 provided in the embodiment of the present application can mainly slit the coated diaphragm 170, such as a water-based coated diaphragm, and is particularly suitable for an oily coated diaphragm, wherein the oily coated diaphragm includes a polymer coating layer and a base film, the polymer coating layer includes a polyvinylidene fluoride homopolymer, a copolymer of polyvinylidene fluoride and hexafluoropropylene, a polyvinylidene fluoride-trichloroethylene copolymer, polyacrylonitrile, and polymethacrylate or at least one of its derivatives, and the base film includes polyethylene, polypropylene, a polyethylene-polypropylene composite film or a non-woven fabric.

[0069] In addition, the membrane slitting device 10 can slit a base membrane that is not provided with a polymer coating layer.

[0070] Test Example 1

[0071] The diaphragm slitting device and diaphragm slitting process provided in Example 1 were used to verify their effect by adjusting the angle of the second cutting knife.

[0072] The diaphragm is a layered coating product of ceramic and PVDF-HFP (copolymer of polyvinylidene fluoride and hexafluoropropylene). The base membrane is a high-performance polymer material obtained by polymerizing polypropylene or polyethylene in a chain form through melting, cooling, stretching and extraction. Then, a ceramic (Al2O3) layer is coated on the surface of the base membrane, and then a layer of PVDF-HFP material is coated to obtain a ceramic and PVDF-HFP diaphragm with stable performance. The thickness of the diaphragm used here is 12±2μm, the air permeability is 200±70s / 100ml, and the surface density is 12±2g / m 2 Ceramic and PVDF-HFP diaphragms.

[0073] The ceramic and PVDF-HFP layered coated diaphragm was unwound at an unwinding tension of 65N, conveyed by the guide roller and conveyed to the flattening roller after exhaust by the clamping mechanism. The angle between the end surface of the flattening roller and the ceramic and PVDF-HFP layered coated diaphragm in contact and the horizontal plane where the center of the flattening roller is located was 40°. The flattened ceramic and PVDF-HFP layered coated diaphragm was then cut by a diaphragm slitting tool, and the warping and glue loss of the products obtained after slitting were counted. The results are shown in Tables 1 and 2.

[0074] Table 1 Statistical data when the second cutting knife is a double-sided flat edge circular knife

[0075]

[0076] Table 2 Statistical data when the second cutting knife is a single-sided circular knife

[0077]

[0078] Among them, the service life of the second cutting knife is evaluated by the length of the slitting membrane in the above Tables 1 and 2. According to Table 1, it can be seen that when the cutting edge angle of the double-sided flat blade is 60°-110°, the proportion of warping and glue falling can be effectively reduced. When the cutting edge angle of the double-sided flat blade is 100°-110°, the service life can be effectively taken into account while reducing the proportion of warping and glue falling.

[0079] According to Table 2, when the edge angle α of the single-sided blade is 30°-50°, the proportion of edge warping and glue peeling is significantly reduced compared with the existing single-sided blade with an edge angle α of 60°.

[0080] Test Example 2

[0081] The membrane slitting device and membrane slitting process provided in Example 1 were used to verify their effects by adjusting the winding tension, unwinding tension, the clamping mechanism and the angle of the first cutting knife.

[0082] Among them, the diaphragm adopts the ceramic-PVDF layered coated diaphragm used in Experimental Example 1, the conveying rate of the ceramic-PVDF layered coated diaphragm is 60m / min, the contact pressure between the ceramic-PVDF layered coated diaphragm and each component is 0.07N / mm, and after being conveyed to the flattening roller under the unwinding tension as shown in Table 3, the angle between the end surface where the flattening roller and the ceramic-PVDF layered coated diaphragm are in contact and the horizontal plane where the center of the flattening roller is located is 40°, and then the flattened ceramic-PVDF layered coated diaphragm is cut by a diaphragm slitting tool, and the product obtained after slitting is rolled up to obtain the corresponding end surface unevenness ratio, oblique wrinkle ratio and glue loss ratio of each group. The specific results are shown in Table 3.

[0083] Table 3 Test parameters and results

[0084]

[0085]

[0086] Among them, the three groups of clamping rollers in Table 3 all refer to Figure 1 The first clamping roller, the second clamping roller and the third clamping roller are shown; in test group 2, 1 set of clamping rollers refers to only the first clamping roller, and 2 sets of clamping rollers refers to only the first clamping roller and the second clamping roller. The two guide rollers between the third clamping roller and the flattening roller are used as the first guide roller and the second guide roller in the membrane transmission direction, wherein 4 sets of clamping rollers refer to that in addition to 3 sets of clamping rollers, a fourth clamping roller is provided between the first guide roller and the second guide roller, and 5 sets of clamping rollers refer to that in addition to 4 sets of clamping rollers, a fifth guide roller is provided between the second guide roller and the flattening roller.

[0087] According to Table 3, the slitting process parameters are as follows: the winding tension is 0.09±0.03N / mm, the conveying device is 3 sets of clamping rollers, the unwinding tension is 60±10N, and the edge angle α of the double-sided blade is 100-110°, the proportion of end surface unevenness is small, the proportion of oblique wrinkles is small, and the proportion of glue loss is small.

[0088] In summary, the diaphragm slitting tool and the diaphragm slitting device including the diaphragm slitting tool can improve the edge angle of the blade of the second cutting knife and adjust the friction resistance between the second cutting knife and the diaphragm, thereby effectively improving the technical problems of glue loss and edge warping of the coated diaphragm during the slitting process, thereby improving the qualified rate of the products after slitting. The diaphragm slitting process using the above-mentioned diaphragm slitting device can also improve the technical problems of glue loss and edge warping of the coated diaphragm during the slitting process.

[0089] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A diaphragm cutting device, characterized in that: It includes an unwinding mechanism, a clamping mechanism, a flattening mechanism, a diaphragm slitting tool, and a winding mechanism which are sequentially arranged along the transmission direction of the diaphragm; Wherein, the clamping and conveying mechanism comprises a first clamping roller, a second clamping roller and a third clamping roller which are sequentially arranged at intervals along the conveying direction of the diaphragm, the travel of the diaphragm between the first clamping roller and the second clamping roller is shorter than the travel of the diaphragm between the third clamping roller and the flattening mechanism, and the travel of the diaphragm between the third clamping roller and the flattening mechanism is shorter than the travel of the diaphragm between the second clamping roller and the third clamping roller; The diaphragm cutting tool comprises two spaced apart cutting portions for cutting off two ends of the diaphragm in the width direction, wherein the diaphragm comprises a first side and a second side along the thickness direction thereof; Each of the cutting parts comprises: a first cutting knife and a second cutting knife, wherein the first cutting knife is located at the first side of the diaphragm and has a supporting surface for supporting the diaphragm, and the second cutting knife is located at the second side of the diaphragm, and the second cutting knife is a circular knife, and the second cutting knife is provided with an annular blade along its outer circumference, and the blade can keep in contact with the supporting surface after cutting the diaphragm; Wherein, the blade is a single-sided blade or a double-sided blade, the blade angle of the single-sided blade is 30°-50°, and the blade angle of the double-sided blade is 60°-110°; When the diaphragm is unwound by the unwinding mechanism, the unwinding tension is controlled to be 60 N±10N, and when the diaphragm product is wound by the winding mechanism, the winding tension is controlled to be 0.09 N / mm±0.03N / mm.

2. The diaphragm cutting device according to claim 1, characterized in that: The cutting edge angle of the double-sided cutting edge is 100°-110°.

3. The diaphragm cutting device according to claim 1, characterized in that: The double-sided blade includes a first bevel and a second bevel connected to each other in the thickness direction of the second cutting blade, and the first bevel and the second bevel are symmetrically arranged along the center line of the second cutting blade.

4. The diaphragm cutting device according to claim 3, characterized in that: The double-sided blade is a V-shaped flat blade.

5. The diaphragm cutting device according to any one of claims 1 to 3, characterized in that: The membrane cutting tool has a transmission mechanism, which is connected to the second cutting knife to drive the second cutting knife to rotate, wherein the movement direction of the blade contacting the membrane is the same as the transmission direction of the membrane.

6. The diaphragm cutting device according to claim 1, characterized in that: The cutting edge angle of the single-sided cutting edge is 30°-45°.

7. A diaphragm slitting process based on the diaphragm slitting device according to claim 1, characterized in that: include: The diaphragm is unrolled by the unwinding mechanism, exhausted by the clamping mechanism, flattened by the flattening mechanism, and then conveyed to the diaphragm slitting tool. The two end portions to be cut off in the width direction of the diaphragm are respectively located between the first cutting knife and the second cutting knife of the corresponding cutting part, and the blade of the second cutting knife is arranged perpendicular to the diaphragm so that the blade can keep contact with the supporting surface after vertically cutting the diaphragm, drive the second cutting knife to rotate, and obtain the finished product after cutting off the two end portions of the diaphragm, and the diaphragm is rolled up by the winding mechanism.

8. The slitting process according to claim 7, characterized in that: The diaphragm includes a polymer coating layer and a base film, the polymer coating layer includes at least one of polyvinylidene fluoride homopolymer, a copolymer of polyvinylidene fluoride and hexafluoropropylene, a polyvinylidene fluoride-trichloroethylene copolymer, polyacrylonitrile, and polymethacrylate or its derivatives, and the base film includes polyethylene, polypropylene, a polyethylene-polypropylene composite film or a non-woven fabric.

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