Method for reducing aluminum scraps on surface of cut aluminum foil

Abstract

The invention belongs to the technical field of battery foils, and particularly relates to a method for reducing aluminum scraps on the surface of a cut aluminum foil. The method comprises the following steps that (1) the aluminum foil (2) is conveyed to a cutter groove roller (3), a rotating disc cutter (1) cuts the aluminum foil (2) to obtain the cut aluminum foil, and aluminum scraps generated at the cutting position are splashed to the back face of the cut aluminum foil (2); and (2) at the downstream of the cutter groove roller (3), an aluminum skimming cleaning roller is used for making contact with the back face of the cut aluminum foil (2) so that aluminum skimming on the back face of the aluminum foil (2) can be removed. The aluminum skimming cleaning roller is used at the downstream of the cutter groove roller (3) to make contact with the back face of the cut aluminum foil (2) so that aluminum skimming on the back face of the aluminum foil (2) can be removed. The aluminum skimming cleaning roller is in direct contact with the aluminum skimming, so that even if the aluminum skimming is adhered to the rolling oil, the aluminum skimming can be removed.

Description

Technical Field

[0001] The invention belongs to the technical field of battery foils, and in particular relates to a method for reducing aluminum scraps on the surface of aluminum foil after cutting. Background Art

[0002] Aluminum foil is a thin sheet material directly rolled from aluminum metal. Due to the soft texture, good ductility, high conductivity and high strength of aluminum, aluminum foil is widely used in product packaging, battery materials and other fields. Especially in lithium-ion batteries, aluminum foil can also be used as current collectors and tabs. The width of aluminum foil shipped from the aluminum factory is very wide, for example, 1200mm wide, while the width of aluminum foil used as tabs in lithium-ion batteries is only 12mm, so it is also necessary to cut the wide aluminum foil into narrow aluminum foil for subsequent use by lithium battery manufacturers.

[0003] The incoming aluminum foil roll goes through the unwinding-cutting-rewinding process to obtain a narrow aluminum foil roll after slitting. In the aluminum foil cutting process, the existing technology designs a disc knife cutting method: a number of annular blades are fixed on the same knife shaft. During the cutting process, the knife shaft drives the annular blades to rotate and cooperate with the knife groove roller to achieve the cutting of aluminum foil. During the cutting process, the knife groove roller supports the aluminum foil similar to a cutting board and positions the blades. Each blade must fall in the middle of its corresponding knife groove for smooth cutting.

[0004] During the cutting process, the high-speed rotating disc cutter contacts the aluminum foil on the knife groove roller and cuts it, which will produce aluminum chips flying everywhere. A large amount of aluminum chips will fly and adhere to the back of the cut aluminum foil. Since the incoming aluminum foil is usually rolled, its surface has rolling oil, and a large amount of aluminum chips will adhere to the rolling oil on the surface of the aluminum foil and are not easy to fall off. In the subsequent winding process, the back and front of the aluminum foil are in contact, so the aluminum chips attached to the back of the aluminum foil will adhere to the front of the aluminum foil, resulting in aluminum chips adhering to the entire surface of the aluminum foil.

[0005] When aluminum foil with aluminum chips attached is used as battery tabs, the aluminum chips on the tabs are easy to scatter and adhere to various places inside the battery, which can easily cause short circuits, puncture the battery separator and other problems, and affect battery performance.

[0006] When conductive paste is coated on aluminum foil with aluminum chips to be used as a battery electrode, it is easy to cause leakage of the conductive paste, uneven coating, etc., which affects the coating effect.

[0007] In order to solve the above problems, the present invention is proposed. Summary of the invention

[0008] The present invention provides a method for reducing aluminum scraps on the surface of aluminum foil after cutting, the method comprising the following steps:

[0009] 1. The aluminum foil 2 is conveyed onto the knife groove roller 3, and the rotating disc cutter 1 cuts the aluminum foil 2 to obtain the cut aluminum foil, and the aluminum scraps generated at the cutting position splash onto the back of the cut aluminum foil 2;

[0010] 2. An aluminum chip cleaning roller is used downstream of the knife groove roller 3 to contact the back side of the cut aluminum foil 2 to remove aluminum chips on the back side of the aluminum foil 2.

[0011] The grooved roller 3 is a roller having a plurality of parallel annular grooves engraved on its circumferential surface, and the aluminum foil 2 wraps a portion of the circumferential surface of the roller at a certain wrap angle. Figure 1 The circumferential surface of the knife groove roller 3 is provided with a plurality of annular knife grooves 31 which are parallel to each other.

[0012] Preferably, the aluminum chip cleaning roller is a wiping roller 5, which is, for example, a steel roller or a rubber roller with a soft sponge layer coated on its surface. When the sponge layer contacts the back of the cut aluminum foil 2, the aluminum chips on the back of the aluminum foil 2 are wiped off the aluminum foil 2.

[0013] Preferably, the aluminum chip cleaning roller is an adhesive roller 6, which is, for example, a steel roller or a rubber roller, and has a sticky material layer such as various adhesives on its surface, so that when the adhesive roller 6 contacts the back of the cut aluminum foil, the sticky material layer sticks the aluminum chips on the back of the aluminum foil off the aluminum foil.

[0014] Preferably, the aluminum chip cleaning roller is a tape roller 7 on which a tape 8 is conveyed. When the adhesive surface of the tape 8 contacts the back of the cut aluminum foil 2 , the tape 8 sticks the aluminum chips on the back of the aluminum foil 2 off the aluminum foil 2 .

[0015] Preferably, the cross-section of the knife groove roller 3 is gear-shaped as a whole, the annular knife grooves 31 are located on the gear teeth in a circumferentially spaced manner, and air suction ports 32 are provided between adjacent gear teeth. The shaft of the knife groove roller 3 is a hollow shaft, and each air suction port is connected to the air flow of the cavity of the hollow shaft, and the cavity is connected to an external negative pressure device; of course, the hollow shaft is also provided with necessary structural features for transmitting torque, because these structural features are irrelevant to the technical problem to be solved by the present invention, Figure 7 The middle part is omitted and not drawn.

[0016] When the disc cutter 1 cuts the aluminum foil 2, the contact surface between the blade of the disc cutter 1 and the aluminum foil 2 is located above the annular knife groove 31, and the aluminum chips generated by the cutting are directly sucked into the suction port 32 through the annular knife groove 31 and discharged from the negative pressure device.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present application uses an aluminum chip cleaning roller downstream of the knife groove roller 3 to contact the back of the cut aluminum foil 2 to remove aluminum chips from the back of the aluminum foil 2. The aluminum chip cleaning roller directly contacts the aluminum chips, so even if the aluminum chips are adhered to the rolling oil, they can be removed.

[0019] 2. In the preferred technical solution, the knife groove roller of the present application is provided with a plurality of suction ports 32 at intervals in the circumferential direction. When the disc cutter 1 cuts the aluminum foil 2, the contact surface between the blade of the disc cutter 1 and the aluminum foil 2 is located above the annular knife groove 31, and most or even all of the aluminum chips generated by the cutting can be directly sucked into the suction port 32 through the annular knife groove 31 and discharged from the negative pressure device. In this process, the aluminum chips are sucked away as soon as they are generated, and will not splash onto the back of the aluminum foil first, adhere to the rolling oil, and then be removed. Therefore, the adhesion of aluminum chips to the surface of the aluminum foil is further reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the knife groove roller 3 in the prior art.

[0021] Figure 2 Schematic diagram of the process of cutting aluminum foil in the prior art.

[0022] Figure 3 for Figure 2 A partial enlarged view of the structure.

[0023] Figure 4 It is a schematic diagram of the first embodiment.

[0024] Figure 5 It is a schematic diagram of the second embodiment.

[0025] Figure 6 It is a schematic diagram of the second embodiment.

[0026] Figure 7 FIG. 4 is a schematic cross-sectional view of an improved knife groove roller 3 in a fourth embodiment.

[0027] Figure 8 This is an enlarged view of the reverse side of Sample 1 in Example 1.

[0028] Fig. 9 This is an enlarged view of the reverse side of sample 2 in Example 1.

[0029] Fig.10 This is an enlarged view of the reverse side of sample 3 in Example 1.

[0030] Fig.11 This is an enlarged view of the reverse side of sample 1 in comparative example 1.

[0031] Fig.12 This is an enlarged view of the reverse side of sample 2 in comparative example 1.

[0032] Fig.13 This is an enlarged view of the reverse side of sample 3 in comparative example 1.

[0033] List of reference numerals:

[0034] 1. Disc cutter, 2. Aluminum foil, 21. Front side of aluminum foil, 22. Back side of aluminum foil, 3. Slotted roller, 31. Annular slot, 32. Air suction port, 4. Conveying roller, 5. Wiping roller, 6. Adhesive roller, 7. Tape stick, 8. Tape. DETAILED DESCRIPTION

[0035] The present invention is described below in conjunction with specific examples, but the embodiments of the present invention are not limited thereto. Experimental methods without specific conditions in the examples are usually carried out according to conventional conditions and conditions described in the manual, or according to the conditions recommended by the manufacturer. The general equipment, materials, reagents, etc. used can be obtained from commercial channels unless otherwise specified. The raw materials required in the following examples and comparative examples are all commercially available.

[0036] The arrows in all figures indicate the direction of movement of the object.

[0037] A method for reducing aluminum scraps on the surface of aluminum foil after cutting, the method comprising the following steps:

[0038] 1 conveys the aluminum foil 2 onto the knife groove roller 3, and the rotating disc cutter 1 cuts the aluminum foil 2 to obtain the cut aluminum foil, and the aluminum scraps generated at the cutting position splash onto the back of the cut aluminum foil 2;

[0039] 2 An aluminum chip cleaning roller is used downstream of the knife groove roller 3 to contact the back side of the cut aluminum foil 2 to remove aluminum chips on the back side of the aluminum foil 2.

[0040] Downstream of the knife groove roller 3 , the cut aluminum foil 2 is conveyed by a conveying roller 4 .

[0041] Figure 2 The schematic diagram of the cutting process of the aluminum foil 2 of the present application takes a side surface of a disc cutter 1 as an example. Figure 2 The direction of the arrow in the middle is the direction of the object's movement. The outer circle of the groove roller 3 corresponds to the top of the annular groove 31. The inner circle (dashed line) of the groove roller 3 corresponds to the bottom of the annular groove 31.

[0042] During cutting, the aluminum foil 2 is conveyed by the knife groove roller 3, and the blade of the disc cutter 1 is located in the knife groove of the knife groove roller 3, and the blade contacts the aluminum foil 2 to achieve cutting of the aluminum foil 2. M is the starting point of contact between the aluminum foil 2 and the disc cutter 1, and N is the end point of contact between the aluminum foil 2 and the disc cutter 1.

[0043] Figure 3 for Figure 2 The aluminum foil 2 is cut at M and aluminum chips are splashed onto the back side 22 of the aluminum foil. Figure 3 The dotted line extending from the middle M indicates the direction of aluminum chips flying.

[0044] In the first embodiment, the aluminum scrap cleaning roller is a wiping roller 5, so that when the wiping roller 5 contacts the back of the cut aluminum foil 2, the aluminum scraps on the back of the aluminum foil 2 are wiped off the aluminum foil 2. The wiping roller can be a sponge roller. The sponge can absorb water or rolling oil. Figure 4 shown.

[0045] In the second embodiment, the aluminum scrap cleaning roller is an adhesive roller 6, and an adhesive material layer is provided on the adhesive roller 6, so that when the adhesive roller 6 contacts the back side 22 of the cut aluminum foil, the adhesive material layer sticks the aluminum scraps on the back side 22 of the aluminum foil off the aluminum foil. Figure 5 shown.

[0046] In a third embodiment, the aluminum scrap cleaning roller is a tape roller 7, and a tape 8 is conveyed on the tape roller 7, so that when the tape roller 7 contacts the back side of the cut aluminum foil 2, the tape 8 sticks the aluminum scraps on the back side 22 of the aluminum foil off the aluminum foil 2. Figure 6 shown.

[0047] In the fourth embodiment, the cross section of the knife groove roller 3 is gear-shaped as a whole, the annular knife grooves 31 are located on the gear teeth in a circumferentially spaced manner, and air suction ports 32 are provided between adjacent gear teeth. The shaft of the knife groove roller 3 is a hollow shaft, and each air suction port is connected to the cavity airflow of the hollow shaft, and the cavity is connected to an external negative pressure device;

[0048] When the disc cutter 1 cuts the aluminum foil 2, the contact surface between the blade of the disc cutter 1 and the aluminum foil 2 is located above the annular knife groove 31, and the aluminum chips generated by the cutting are directly sucked into the suction port 32 through the annular knife groove 31 and discharged from the negative pressure device.

[0049] The three-dimensional structure of the conventional knife groove roller 3 is as follows Figure 1 The cross-sectional view of the improved knife groove roller 3 is shown in FIG. Figure 7 shown. Figure 7 This is only a schematic diagram. In actual applications, the intervals between adjacent air suction ports 32 are very small, while the number of air suction ports 2 is large.

[0050] Example 1

[0051] A method for reducing aluminum scraps on the surface of aluminum foil after cutting, the method comprising the following steps:

[0052] 1 conveys the aluminum foil 2 onto the knife groove roller 3, and the rotating disc cutter 1 cuts the aluminum foil 2 to obtain the cut aluminum foil, and the aluminum scraps generated at the cutting position splash onto the back of the cut aluminum foil 2;

[0053] 2 An aluminum scrap cleaning roller is used downstream of the knife groove roller 3 to contact the back side of the cut aluminum foil 2 to remove aluminum scraps on the back side of the aluminum foil 2, and finally the aluminum foil roll is rolled up.

[0054] Downstream of the knife groove roller 3 , the cut aluminum foil 2 is conveyed by a conveying roller 4 .

[0055] The aluminum scrap cleaning roller is a wiping roller 5, so that when the wiping roller 5 contacts the back of the cut aluminum foil 2, the aluminum scraps on the back of the aluminum foil 2 are wiped off from the aluminum foil 2. The wiping roller can be a sponge roller. The sponge absorbs water. Figure 4 shown.

[0056] The diameter of the grooved roller 3 is 1200 mm, and a series of parallel annular grooves 31 are provided on its circumference. The width of the annular grooves 31 is 1 mm and the depth is 3 mm. The width of the aluminum foil 2 before cutting is 1200 mm, and it is cut into two pieces by a rotating disc cutter 1 to obtain two 600 mm aluminum foil strips. The rotation speed of the grooved roller 3 is 180 m / min, and the rotation speed of the disc cutter 1 is 300 m / min.

[0057] Example 2

[0058] On the basis of Example 1, a series of evenly arranged air suction ports 32 are arranged at circumferential intervals on the knife groove roller 3, and the knife groove roller 3 has a hollow shaft, and each air suction port 32 is connected to the airflow of the cavity of the hollow shaft, and the cavity is connected to the airflow of the external negative pressure device;

[0059] When the disc cutter 1 cuts the aluminum foil 2, the contact surface between the blade of the disc cutter 1 and the aluminum foil 2 is located above the annular knife groove 31, and the aluminum chips generated by the cutting are directly sucked into the suction port 32 through the annular knife groove 31 and discharged from the negative pressure device.

[0060] The opening width of the air suction port 32 is 10 mm, and the arc length of the annular knife groove 31 between adjacent air suction ports 32 is 20 mm. The pressure of the negative pressure device is -50 kPa.

[0061] Comparative Example 1

[0062] Compared with Example 1, only the aluminum chip cleaning roller is not provided, and other operations are the same.

[0063] Results test:

[0064] The aluminum foil rolls were finally rolled up for the embodiments and comparative examples, and samples were taken to obtain aluminum foil sheets of 1 square centimeter. The number of aluminum scraps on both sides of the aluminum foil sheets was tested using the 3M tape method. Three samples were taken for each embodiment and comparative example for testing.

[0065] The specific method is: cut 3M tapes with specifications of 50mm×50mm, adhere them to the surface of the sample to be tested, press and squeeze them flat, leave them for 30s, tear them off from the surface of the sample to be tested, and then observe the adhesive surface of the 3M tape by 40×10 times magnification, and count the number of aluminum chips observed. The results are shown in Table 1.

[0066] Table 1 proves that 1. The method of setting the aluminum chip cleaning roller in the present application can significantly reduce the aluminum chips on the surface of the aluminum foil after cutting. 2. Setting the suction groove on the knife groove roller can further reduce the aluminum chips on the surface of the aluminum foil after cutting. After the suction groove is set in the present application, there is no aluminum chips on the surface of the aluminum foil sample tested.

[0067]

[0068] Figure 8 This is an enlarged view of the reverse side of Sample 1 in Example 1. Fig. 9 This is an enlarged view of the reverse side of sample 2 in Example 1.

[0069] Fig.10 This is an enlarged view of the reverse side of sample 3 in Example 1. Fig.11 This is an enlarged view of the reverse side of sample 1 in comparative example 1.

[0070] Fig.12 This is an enlarged view of the reverse side of sample 2 in comparative example 1. Fig.13 This is an enlarged view of the reverse side of sample 3 in comparative example 1.

Claims

1. A method for reducing aluminum scraps on the surface of aluminum foil after cutting, characterized in that: The method comprises the following steps: Step (1), conveying the aluminum foil (2) onto a knife groove roller (3), and the rotating disc cutter (1) cuts the aluminum foil (2) to obtain cut aluminum foil, and aluminum chips generated at the cutting position splash onto the back of the cut aluminum foil (2); Step (2), using an aluminum chip cleaning roller downstream of the knife groove roller (3) to contact the back side of the cut aluminum foil (2) to remove aluminum chips on the back side of the aluminum foil (2).

2. The method according to claim 1, characterized in that The aluminum chip cleaning roller is a wiping roller (5), so that when the wiping roller (5) contacts the back side of the cut aluminum foil (2), the aluminum chips on the back side of the aluminum foil (2) are wiped off the aluminum foil (2).

3. The method according to claim 1, characterized in that The aluminum scrap cleaning roller is an adhesive roller (6), and a sticky material layer is arranged on the roller surface of the adhesive roller (6), so that when the adhesive roller (6) contacts the back side of the cut aluminum foil, the sticky material layer sticks the aluminum scraps on the back side of the aluminum foil off the aluminum foil.

4. The method according to claim 1, characterized in that: The aluminum scrap cleaning roller is a tape roller (7), and a tape (8) is conveyed on the tape roller (7), so that when the tape roller (7) contacts the back of the cut aluminum foil (2), the tape (8) sticks the aluminum scraps on the back of the aluminum foil (2) off the aluminum foil (2).

5. The method according to claim 1, characterized in that The circumferential surface of the grooved roller (3) is provided with a plurality of annular grooves (31) parallel to each other; The cross section of the knife groove roller (3) is gear-shaped as a whole, the annular knife grooves (31) are located on the gear teeth in a circumferentially spaced manner, and air suction ports (32) are provided between adjacent gear teeth. The shaft of the knife groove roller (3) is a hollow shaft, and each air suction port is connected to the air flow of the cavity of the hollow shaft, and the cavity is connected to an external negative pressure device; When the disc cutter (1) cuts the aluminum foil (2), the contact surface between the blade of the disc cutter (1) and the aluminum foil (2) is located above the annular knife groove (31), and aluminum chips generated by cutting are directly sucked into the air suction port (32) through the annular knife groove (31) and discharged from the negative pressure device.

Images