CN114888897A

CN114888897A - Membrane cutting method

Info

Publication number: CN114888897A
Application number: CN202210431961.2A
Authority: CN
Inventors: 黄承玉; 曹杰; 余招宇; 曹辉
Original assignee: Rept Battero Energy Co Ltd
Current assignee: Rept Battero Energy Co Ltd
Priority date: 2022-04-22
Filing date: 2022-04-22
Publication date: 2022-08-12
Anticipated expiration: 2042-04-22
Also published as: CN114888897B

Abstract

The invention relates to a membrane cutting method, which comprises the following steps: pre-cutting the edge of the membrane along the running direction vertical to the membrane at a pre-cutting station to form an opening on the edge of the membrane; the film is cut completely at the cutting station along the running direction vertical to the film. According to the membrane cutting method, due to the fact that the edge of the membrane is pre-cut, the opening formed in the edge of the membrane can release the edge warping stress caused by extension and the like of the membrane, and therefore edge cutting burrs and poor edge extension can be obviously reduced.

Description

Membrane cutting method

Technical Field

The invention relates to the technical field of cutting, in particular to a membrane cutting method.

Background

At present, a battery cell consists of a positive plate, a negative plate and a diaphragm, the positive plate, the negative plate and the diaphragm are wound and formed and are accommodated in a steel shell, the positive plate, the negative plate and the diaphragm are respectively prepared by different stations before the battery cell is prepared, the positive plate, the negative plate and the diaphragm need to be cut into rated sizes, and the battery cell is manufactured through the processes of laminating and winding.

In the related art, a general cutting technology is to cut a film by using a cutting knife after forcibly extending the film, but the edge extension of the cutting technology is not removed, and the cutting problems such as cutting burrs and the like are not fundamentally improved.

Therefore, there is a need to provide a new film cutting method to overcome the above problems.

Disclosure of Invention

The embodiment of the invention provides a membrane cutting method, which aims to solve the problem that the cutting problems of cutting burrs and the like are not fundamentally improved in a cutting mode of forcibly extending a membrane and then cutting by using a cutting knife in the related art.

In a first aspect, there is provided a film slitting process comprising the steps of: pre-cutting the edge of the membrane along the running direction vertical to the membrane at a pre-cutting station to form an opening on the edge of the membrane; the film is cut completely at the cutting station along the running direction vertical to the film.

In some embodiments, after the pre-cutting station pre-cuts the edge of the film sheet in a direction perpendicular to the running direction of the film sheet to form the opening, the method further comprises: the driving diaphragm moves to a cutting station around the flattening roller.

In some embodiments, the central angle of the contact surface of the film sheet with the nip roll is greater than or equal to 60 °.

In some embodiments, the surface of the nip roll has a spiral pattern having a depth of less than 1.5 times the film thickness.

In some embodiments, the pre-cutting station is provided with a first upper knife and a first lower knife, the first upper knife is a diagonal knife, and the first lower knife is a straight knife.

In some embodiments, the cutting station is provided with a second upper knife and a second lower knife, both of which are straight knives.

In some embodiments, the edge profile of the second upper knife is a sawtooth profile.

In some embodiments, after the cutting station cuts the entire film sheet in a direction perpendicular to the running direction of the film sheet, the method further comprises: two opposing nip rolls are used to nip the film web.

In some embodiments, one of the opposing pinch rolls is a fixed roll, the other opposing pinch roll is a movable roll, and the stroke and the pressing force of the opposing pinch roll are controlled by a cylinder or a motor.

In some embodiments, the two opposing nip rollers have different roughnesses.

The technical scheme provided by the invention has the beneficial effects that:

the embodiment of the invention provides a membrane cutting method, because the edge of a membrane is pre-cut, the opening formed at the edge of the membrane can release the edge warping stress caused by extension and the like of the membrane, and therefore, the edge cutting burr and poor edge extension can be obviously reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic flow chart of a film cutting method according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a cutting process of a film provided in an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of a pre-cutting station provided in accordance with an embodiment of the present invention;

FIG. 4 is a schematic side view of a pre-cutting station according to an embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view of a cutting station provided in accordance with an embodiment of the present invention;

fig. 6 is a schematic side view of a cutting station according to an embodiment of the present invention.

In the figure:

1. pre-cutting station; 11. a first upper knife; 12. a first lower cutter;

2. cutting stations; 21. a second upper knife; 22. a second lower cutter;

3. a membrane; 4. flattening rollers; 5. oppositely clamping the roller; 6. a clamping plate; 7. and horizontally passing through a roller.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The embodiment of the invention provides a membrane cutting method, which can solve the problem that the cutting problems of cutting burrs and the like are not fundamentally improved in a cutting mode of forcibly extending a membrane and then cutting by using a cutting knife in the related art.

Referring to fig. 1, a film cutting method according to an embodiment of the present invention may include the following steps:

s1: the edge of the membrane 3 is precut in a precut station 1 along a direction perpendicular to the running direction of the membrane 3, so that the edge of the membrane 3 forms an opening.

In this embodiment, the operation direction of the membrane 3 is longitudinal, the operation direction perpendicular to the membrane 3 is transverse, the pre-cutting knives may be disposed on two transverse opposite sides of the membrane 3 at the pre-cutting station 1, and the edges of the membrane 3 are pre-cut on two opposite sides of the membrane 3 to form an opening, wherein the length of the single-side pre-cut of the membrane 3 is preferably less than 5 mm.

S2: the film web 3 is cut completely at the cutting station 2 in a direction perpendicular to the direction of travel of the film web 3. That is, the membrane 3 is integrally cut after the pre-cutting, the cutting position of the cutting station 2 is preferably overlapped with the cutting position of the pre-cutting station 1, and of course, in the actual cutting process, the cutting position of the cutting station 2 may slightly deviate from the cutting position of the pre-cutting station 1.

In this embodiment, owing to cut the edge of station 1 to diaphragm 3 in advance earlier and cut in advance, can form the opening at the edge of diaphragm 3, the opening can fall diaphragm 3 itself owing to reasons such as extension stick up limit stress release that cause, carries out subsequent cutting process again, can obviously reduce edge cutting burr and edge extension bad.

In some embodiments, referring to fig. 2, after pre-cutting the edge of the film 3 in a direction perpendicular to the running direction of the film 3 at the pre-cutting station 1 to form an opening on the edge of the film 3, the method may further include: the driving film 3 is moved to the cutting station 2 around the nip roller 4. That is to say, a flattening roller 4 is arranged between the pre-cutting station 1 and the cutting station 2, the membrane 3 is flattened by the flattening roller 4 after being pre-cut and then moves to the cutting station 2 for integral cutting, and the flattening roller 4 can be made of alloy, carbon fiber and the like; the flattening roller 4 is beneficial to releasing transverse stress of the pre-cut membrane 3, the edge of the raised edge and the main body of the membrane 3 are ensured not to generate extension, wrinkles and the like, the further flattening roller 4 is also beneficial to plasticity of the membrane 3, and the transverse rigidity of the membrane 3 is improved; the surface of the nip roll 4 should meet the roughness requirements.

In some alternative embodiments, the trajectory of the film 3 may be a straight line or an oblique line, the selected trajectory may depend on the space and processing requirements, and the central angle of the contact surface of the film 3 with the nip roller 4 may be greater than or equal to 60 °. That is to say that the contact surface of diaphragm 3 and nip roll 4 is arc, and this arc central angle is not less than 60, can guarantee that nip roll 4 shows good exhibition flat effect.

Preferably, the nip roll 4 is a driven roll, the surface of the nip roll 4 may have spiral patterns, the depth and width of the spiral patterns are selected according to the application product and the processing, the depth of the spiral patterns is preferably less than 1.5 times of the thickness of the film 3, the width has no special requirement, and further, the spiral angle of the spiral patterns is determined according to the application product and the processing. The material of the flattening roller 4 can be selected from alloy, carbon fiber and other materials, and is special, the material of the spiral patterns on the surface of the roller body of the flattening roller 4 can be inconsistent with that of the roller body, and the material is selected according to application products and processing.

In some embodiments, referring to fig. 3 and 4, the pre-cutting station 1 may be provided with a first upper knife 11 and a first lower knife 12, the first upper knife 11 is an inclined knife, the first lower knife 12 is a straight knife, and the first upper knife 11 and the first lower knife 12 need to be matched for cutting; further, the shapes of the cutting edges of the first upper knife 11 and the first lower knife 12 can be selected from opposite single edge, double edge, sawtooth and the like, and the selection type is determined according to application products and processing; further, the pre-cutting action of the pre-cutting station 1 can adopt a passive cutting action of actively cutting the first lower cutter 12 by the first upper cutter 11, or can adopt an action design of actively cutting both the first upper cutter 11 and the first lower cutter 12, and the selection is determined according to application products and processing; the materials of the first upper knife 11 and the first lower knife 12 can be selected from alloy, ceramic and other materials, and the materials are selected according to application products and processing; straight sword and oblique sword are the cutter shape, and in this embodiment, first upper slitter 11 adopts the oblique sword more to do benefit to and forms 3 openings of diaphragm, because in cutting station 1 in advance at 3 edge formation openings on the diaphragm can, choose for use the oblique sword better. More specifically, the first upper knife 11 is a triangle-like oblique knife and a single-cutting-edge type, the first lower knife 12 is a parallel straight knife, and the single-cutting-edge type is opposite to the single-cutting-edge direction of the first upper knife 11, so that the shearing force for cutting the membrane 3 is increased.

In some alternative embodiments, as shown in fig. 5 and 6, the cutting station 2 may be provided with a second upper knife 21 and a second lower knife 22, both the second upper knife 21 and the second lower knife 22 being straight knives, the straight knives being knife-shaped. In this embodiment, at the cutting station 2, the second upper knife 21 and the second lower knife 22 need to be cut in cooperation; further, the shapes of the cutting edges of the second upper knife 21 and the second lower knife 22 can be selected from opposite single edge, double edge, sawtooth and the like, and the selection type is determined according to application products and processing; the further cutting action of the cutting station 2 can adopt a passive cutting action of actively cutting the second lower cutter 22 by the second upper cutter 21, or adopt an action design of actively cutting both the second upper cutter 21 and the second lower cutter 22, and the selection is determined according to application products and processing; the materials of the second upper knife 21 and the second lower knife 22 can be selected from alloy, ceramic and other materials, and the materials are selected according to application products and processing. In this embodiment, the second upper knife 21 and the second lower knife 22 both adopt straight knives, which is beneficial to reducing burrs during the overall cutting process of the membrane 3.

Preferably, the edge of the second upper knife 21 is sawtooth-shaped, the cutting effect of the sawtooth-shaped second upper knife 21 is relatively good, and the phenomenon that the membrane 3 is shawl or the membrane 3 is broken does not occur basically. The number and size of the teeth of the second upper knife 21 are selected according to the material thickness of the membrane 3.

In some embodiments, referring to fig. 2, after the cutting station 2 cuts all the film 3 in the direction perpendicular to the running direction of the film 3, it may further include: two opposite clamping rollers 5 are used for clamping the membrane 3; the two opposite clamping rollers 5 can provide traction for the film 3 to pull the film 3 to move.

Still be equipped with horizontal roller 7 before cutting station 1 in advance, diaphragm 3 can move to cutting station 1 in advance around horizontal roller 7, and horizontal roller 7 can play the effect of drawing diaphragm 3.

Further, as shown in fig. 2, a clamping plate 6 may be further disposed between the cutting station 2 and the nip roll 4, and the clamping plate 6 may clamp the membrane 3 and pull and move the membrane 3 between the pre-cutting station 1 and the cutting station 2, so as to ensure that the membrane 3 can smoothly move to the cutting station 2.

Further, one of the opposite clamping rollers 5 is preferably a fixed roller, the other opposite clamping roller 5 is a movable roller, and the stroke and the extrusion force of the opposite clamping roller 5 are controlled by an air cylinder or a motor, so that the two opposite clamping rollers 5 can clamp the diaphragms 3 with different thicknesses, and the adjustment of the extrusion force can be realized. The two opposite clamping rollers 5 meet the requirement of relative parallelism, the materials of the opposite clamping rollers 5 can be selected from alloys, carbon fibers and the like, the surface roughness can be selected from a mirror surface standard (more than Ra1.0) or a standard (more than Ra1.0) with larger roughness, and the selected roughness is determined according to application products and processing; the material of the two opposite clamping rollers 5 can be different, and the material is selected according to the application product and processing.

Further, when the opposite clamping rollers 5 are selected, the roughness of the two opposite clamping rollers can be different, and the different roughness of the two sides can provide stable and reliable traction force.

In the description of the present invention, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present invention. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly and encompass, for example, both fixed and removable coupling as well as integral coupling; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

It is noted that, in the present invention, relational terms such as "first" and "second", and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A film cutting method, characterized in that it comprises the steps of:

pre-cutting the edge of the membrane (3) along the running direction vertical to the membrane (3) at a pre-cutting station (1) to form an opening at the edge of the membrane (3);

the film (3) is cut completely at the cutting station (2) along the running direction vertical to the film (3).

2. The film cutting method according to claim 1, wherein after the pre-cutting station (1) pre-cuts the edge of the film (3) in a direction perpendicular to the running direction of the film (3) so that the edge of the film (3) forms an opening, the method further comprises: the driving membrane (3) bypasses the flattening roller (4) to move to the cutting station (2).

3. The film slitting process of claim 2 wherein: the central angle of the contact surface of the membrane (3) and the flattening roller (4) is greater than or equal to 60 degrees.

4. The film slitting process of claim 2 wherein:

the surface of the flattening roller (4) is provided with spiral patterns, and the depth of the spiral patterns is less than 1.5 times of the thickness of the membrane (3).

5. The film slitting process of claim 1 wherein:

the pre-cutting station (1) is provided with a first upper cutter (11) and a first lower cutter (12), the first upper cutter (11) is an inclined cutter, and the first lower cutter (12) is a straight cutter.

6. The film slitting process of claim 1 wherein:

the cutting station (2) is provided with a second upper cutter (21) and a second lower cutter (22), and the second upper cutter (21) and the second lower cutter (22) are straight cutters.

7. The film slitting process of claim 6 wherein: the edge shape of the second upper knife (21) is a sawtooth shape.

8. The film slitting process of claim 1 wherein: after cutting station (2) is along the traffic direction of perpendicular to film piece (3) with film piece (3) whole division, still include:

the film (3) is clamped by two opposite clamping rollers (5).

9. The film slitting process of claim 8 wherein:

one of the opposite clamping rollers (5) is a fixed roller, the other opposite clamping roller (5) is a movable roller, and the stroke and extrusion force of the opposite clamping roller (5) are controlled by an air cylinder or a motor.

10. The film slitting process of claim 8 wherein:

the roughness of the two opposite clamping rollers (5) is different.