A jig for detecting bending resistance of foil and a detection method thereof

Abstract

The present invention discloses a jig for testing the bending resistance of foil, comprising a workbench, on which a left swing mechanism and a right swing mechanism are arranged at intervals, and the structure of the left swing mechanism is symmetrical to that of the right swing mechanism; a slider is arranged between the left swing mechanism and the right swing mechanism, and the slider can slide left and right relative to the workbench; the slider is connected to a driver; a rear fixing block is arranged on the workbench, and a rear suction cup is arranged on the rear fixing block. The present invention can perform bending resistance tests on specific positions of foil materials, and can test the differences in bending resistance of the same foil material or different foil materials; the micropores detected by the present invention are caused by the inability of the foil material to overcome its own bending stress, and the contact between the bending point and the jig is avoided, so that the micropores can be captured in time, and whether the sample to be tested fails due to bending can be monitored in time.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum-plastic packaging film, copper foil and aluminum foil bending resistance detection, and in particular to a jig for detecting the bending resistance of foil and a detection method thereof. Background Art

[0002] With the development of the times, the replacement of consumer electronic products and the promotion of new energy vehicles in the country, lithium-ion secondary batteries have played an important role in people's lives. To stand out in the fierce competition, lithium batteries need to develop in the direction of higher energy density, longer cycle life, and more reliable safety. For the same material, the most direct and common way to increase energy density is to reduce the thickness of the material. However, after the thickness of the raw material is thinned, other problems will arise accordingly, such as poor bending resistance, which makes the result fail to meet the expected performance requirements.

[0003] Aluminum-plastic packaging film is mainly composed of nylon, aluminum foil, and PP, and is widely used in the packaging of food, electronics, and cutting-edge defense products. Aluminum-plastic packaging film plays an important role in soft-pack lithium-ion batteries, requiring it to have good deep drawing properties, electrolyte stability, extremely high barrier properties, and bending resistance. In the production process of soft-pack lithium batteries, aluminum-plastic packaging film needs to go through processes such as shell punching, top and side sealing, secondary sealing, and folding to make the sheet-shaped aluminum-plastic packaging film into a packaging bag. This requires the aluminum-plastic packaging film to have good folding resistance. Aluminum-plastic packaging film with poor folding resistance often has corner cracks or damage, which eventually leads to battery scrapping. At present, there is no unified and reliable method to test the bending resistance of aluminum-plastic packaging film, and many manufacturers cannot choose the right material from a large number of materials. Therefore, it is imperative to invent a new and reliable method to evaluate the bending resistance of foil.

[0004] At present, the bending resistance of foil is mainly divided into two methods: manual bending and automatic bending. The basic steps of general manual bending are: cut the sample into strips of about 150mm long and 15mm wide, and estimate the number of bending resistance of the strip first. Hold one end of the strip with each hand, fold the strip in half, and then fold it back and forth 90° along the crease. When the estimated number of bends is reached, face the strip toward the light source to check if there is a hole. If no hole appears, continue to fold it in half once and check if there is a hole until a hole appears. If the estimated number of bends is reached and the strip has a hole, reduce the number of bends. The experiment defines the number of bends without a hole as the bending resistance value of the material. Patent CN 106248503 A "A method for testing the folding resistance of aluminum-plastic packaging film" describes a method for automatic bending test. The general test steps are as follows: clamp one end of the cut sample with a clamp, hang a weight at the other end of the sample, set a certain angle for swing bending, and after reaching the estimated number of times, face the bent part to the light source to check whether there is a hole. When the aluminum-plastic packaging film just has no hole, the number of bends performed is the bending resistance value of the material.

[0005] The disadvantage of manual bending is that the repeatability is poor, and the measured bending resistance times of the foil vary greatly. When bending automatically, there is friction between the spline and the fixture, and the spline with the heavy object hanging will extend under the action of external force, the bending position will change, the measured result will have a certain deviation, and automatic detection cannot be achieved. The present invention adopts a method of single-point bending and real-time detection of foil, which not only realizes automatic bending, but also realizes automatic inspection, especially timely monitoring of whether the sample to be tested is bent and fails. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art and to provide a simple-structured, convenient-operation, and practical jig and method for detecting the bending resistance of foil.

[0007] The present invention is achieved by the following methods:

[0008] A jig for detecting the bending resistance of foil, characterized in that: it comprises a workbench, on which a left swing mechanism and a right swing mechanism are arranged at intervals, and the structure of the left swing mechanism is symmetrical to the structure of the right swing mechanism; a slider is arranged between the left swing mechanism and the right swing mechanism, and the slider can slide left and right relative to the workbench; the slider is connected to a driver; a rear fixing block is arranged on the workbench, and a rear suction cup is arranged on the rear fixing block; a light beam transmitter is arranged on the workbench, and a light beam receiver matched with the light beam transmitter is arranged above the workbench.

[0009] Furthermore, the right swing mechanism includes a support rod, a sliding rod, a shift rod, and a side suction cup, the support rod is connected to the workbench, the shift rod is arranged on the workbench, and the shift rod is located on the side of the support rod; the shift rod is rotatable relative to the workbench; a hinge is provided on the shift rod, and a side suction cup is provided on the hinge; one end of the sliding rod is connected to the support rod, and the other end of the sliding rod is connected to the side suction cup; the slider is connected to the sliding rods on the left swing mechanism and the right swing mechanism through a guide block; the slider moves to the left or right, driving the shift rod to move outward or inward, and then driving the side suction cups on the left swing mechanism and the right swing mechanism to swing outward or inward.

[0010] Furthermore, the moving rod is connected to the workbench through a moving block.

[0011] A method for detecting a jig for detecting the bending resistance of foil, characterized in that it comprises the following steps:

[0012] a. Cut the foil to be tested into square foils, and ensure that the square foils are intact, flat and wrinkle-free;

[0013] b. Attach the square foil to the side of a cylinder with a radius of 5mm-100mm, and roll the square foil into a cylindrical shape around the side of the cylinder. Release it after 1 minute to keep the square foil in a natural bending state.

[0014] c. Select a detection vertex from the square foil after curling, manually press lightly on the inner side of the curved surface, and at the same time rotate the left and right corners of the square foil outward until the left and right corners are close together; then connect the rear part of the square foil with the rear suction cup, and the left and right corners are respectively connected to the side suction cups on the left swing mechanism and the right swing mechanism, and move the slider to the left or right to drive the shift rod to move outward or inward, thereby driving the side suction cups on the left swing mechanism and the right swing mechanism to swing outward or inward to bend the square foil, ensuring that the detection vertex position remains unchanged when the square foil is bent, and at the same time, the light point of the light beam transmitter is facing the detection vertex. When the square foil is punctured, the light beam receiver receives the light beam signal from the light beam transmitter, the slider stops moving, and the number of bends is recorded.

[0015] Furthermore, the bending angle between the left corner and the right corner is 0°-90°.

[0016] The beneficial effects of the present invention are as follows: a bending resistance test can be performed on a specific position of a foil, and the difference in bending resistance of the same foil or different foils can be tested; the micropores detected by the present invention are caused by the foil being unable to overcome its own bending stress, and the contact between the bending point and the jig is avoided, the micropores can be captured in time, and whether the sample to be tested fails due to bending can be monitored in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1Schematic diagram of the structure of the present invention. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described in detail below through specific embodiments and in combination with the accompanying drawings. It should be understood that the embodiments of the present invention are not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0019] A jig for testing the bending resistance of foil, such as Figure 1 As shown, it includes a workbench 1, on which a left swing mechanism and a right swing mechanism are arranged at intervals, and the structure of the left swing mechanism is symmetrical to that of the right swing mechanism; a slider 2 is arranged between the left swing mechanism and the right swing mechanism, and the slider 2 can slide left and right relative to the workbench 1; the slider 2 is connected to the driver; a rear fixing block 3 is arranged on the workbench 1, and a rear suction cup 4 is arranged on the rear fixing block 3; a light beam transmitter 12 is arranged on the workbench 1, and a light beam receiver 13 matched with the light beam transmitter 12 is arranged above the workbench 1; the right swing mechanism includes a support rod 5, a slide rod 6, a shift rod 7, and a side suction cup 8, The support rod 5 is connected to the workbench 1, and the shift rod 7 is connected to the workbench 1 through the moving block 11, and the shift rod 7 is located on the side of the support rod 5; the shift rod 7 is rotatable relative to the workbench 1; a hinge 9 is provided on the shift rod 7, and a side suction cup 8 is provided on the hinge 9; one end of the slide rod 6 is connected to the support rod 5, and the other end of the slide rod 6 is connected to the side suction cup 8; the slider 2 is connected to the slide rod 6 on the left swing mechanism and the right swing mechanism through the guide block 10; the slider 2 moves to the left or right, driving the shift rod 7 to move outward or inward, and then driving the side suction cups 8 on the left swing mechanism and the right swing mechanism to swing outward or inward.

[0020] Embodiment 1:

[0021] In this embodiment 1, the bending speed is 20 times / min, the bending angle is 0° to 90°, and the speed is uniform and there is no jamming during the bending process. In this embodiment 1, the foil material is an aluminum-plastic packaging film with a total thickness of 88um and a structure of 15umPA / 35umAL / 25umCPP. The specific test steps are as follows:

[0022] a. Cut the foil to be tested into square foils with a length of 200 mm and a width of 200 mm, a total of 10 pieces;

[0023] b. Attach the square foil to the side of a cylinder with a radius of 30 mm, and manually roll the square foil into a cylindrical shape around the side of the cylinder. Release it after 1 minute to keep the square foil in a natural bending state.

[0024] c. Select a detection vertex 21 from the square foil after curling, manually press lightly on the inner side of the curved surface, and at the same time, rotate the left corner 22 and the right corner 23 of the square foil outward until the left corner 22 and the right corner 23 are close to each other; then connect the rear part 24 of the square foil with the rear suction cup 4, and connect the left corner 22 and the right corner 23 with the side suction cups 8 on the left swing mechanism and the right swing mechanism respectively, and move the slider 2 to the left or right to drive the shift rod 7 to move outward or inward, thereby driving the side suction cups 8 on the left swing mechanism and the right swing mechanism to swing outward or inward, so as to bend the square foil, and ensure that the square foil is bent. , the position of the detection vertex 21 remains unchanged, and the light point of the light beam transmitter 12 is facing the detection vertex 21. After it is fixed in place, the angle to be rotated is selected, the slider 2 starts to work, and the square foil starts to open and close. After completing one action, the counter records one number. When the square foil is punctured, the light beam receiver 13 receives the light beam signal of the light beam transmitter 12, the slider 2 stops moving, and the sample is removed. The value displayed on the counter is the number of times the square foil can withstand bending. Repeat the above steps until the sample test is completed, and the average value of the 10 results is 13.8, that is, the bending resistance value of the material is 13.8.

[0025] The following table shows the bending performance test of the aluminum-plastic film of Example 1 by manual bending, and records the relevant data:

[0026]

[0027]

[0028] Example 2

[0029] In this Example 2, the bending speed is 15 times / min, the bending angle is 0° to 80°, and the speed is uniform and there is no jamming during the bending process; the foil material in this Example 2 is 12um single-sided smooth aluminum foil, and the specific test steps for its bending resistance are as follows:

[0030] a. Cut the foil to be tested into square foils with a length of 150 mm and a width of 150 mm, a total of 10 pieces;

[0031] b. Attach the square foil to the side of a cylinder with a radius of 15 mm, and manually roll the square foil into a cylindrical shape around the side of the cylinder. Release it after 1 minute to keep the square foil in a natural bending state.

[0032] c. Select a detection vertex 21 from the square foil after curling, manually press lightly on the inner side of the curved surface, and at the same time, rotate the left corner 22 and the right corner 23 of the square foil outward until the left corner 22 and the right corner 23 are close to each other; then connect the rear part 24 of the square foil with the rear suction cup 4, and connect the left corner 22 and the right corner 23 with the side suction cups 8 on the left swing mechanism and the right swing mechanism respectively, and move the slider 2 to the left or right to drive the shift rod 7 to move outward or inward, thereby driving the side suction cups 8 on the left swing mechanism and the right swing mechanism to swing outward or inward, so as to bend the square foil, and ensure that the square foil is bent. , the position of the detection vertex 21 remains unchanged, and the light point of the light beam transmitter 12 is facing the detection vertex 21. After it is fixed in place, the angle to be rotated is selected, the slider 2 starts to work, and the square foil starts to open and close. After completing one action, the counter records one number. When the square foil is punctured, the light beam receiver 13 receives the light beam signal of the light beam transmitter 12, the slider 2 stops moving, and the sample is removed. The value displayed on the counter is the number of times the square foil can withstand bending. Repeat the above steps until the sample test is completed. The average value of the 10 results is 16.2, that is, the bending resistance value of the material is 16.2.

[0033] The following table shows the bending performance test of the aluminum-plastic film of Example 2 by manual bending, and records the relevant data:

[0034]

[0035] It can be known from the results of Example 1 and Example 2 that the detection method of the fixture for detecting the bending resistance of foil of the present invention can effectively solve the shortcomings of the current bending resistance test such as poor accuracy and poor repeatability. The present invention uses micropores to detect the bending resistance of foil, and can detect different positions on the same material, and conduct targeted inspections on a certain point; the present invention uses real-time online detection means to capture the micropores of the foil in time, so as to accurately judge the bending resistance of the foil. The testing method of the present invention has strong stability and high repeatability, and can be used for testing the bending resistance of various foils, and comparing the differences in the bending resistance of different foils. Therefore, the present invention effectively solves the technical difficulties in the bending resistance inspection of foil in the industry, and has a high industrial practical value.

[0036] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A jig for testing the bending resistance of foil, characterized in that: The invention comprises a workbench (1), wherein a left swing mechanism and a right swing mechanism are arranged at intervals on the workbench (1), and the structure of the left swing mechanism is symmetrical with the structure of the right swing mechanism; a slider (2) is arranged between the left swing mechanism and the right swing mechanism, and the slider (2) can slide left and right relative to the workbench (1); the slider (2) is connected to a driver; a rear fixing block (3) is arranged on the workbench (1), and a rear suction cup (4) is arranged on the rear fixing block (3); a light beam transmitter (12) is arranged on the workbench (1), and a light beam receiver (13) matched with the light beam transmitter (12) is arranged above the workbench (1).

2. A jig for testing the bending resistance of foil according to claim 1, characterized in that: The right swing mechanism comprises a support rod (5), a slide rod (6), a shift rod (7), and a side suction cup (8); the support rod (5) is connected to the workbench (1); the shift rod (7) is arranged on the workbench (1), and the shift rod (7) is located on the side of the support rod (5); the shift rod (7) is rotatable relative to the workbench (1); a hinge (9) is arranged on the shift rod (7), and a side suction cup (8) is arranged on the hinge (9); one end of the slide rod (6) is connected to the support rod (5), and the other end of the slide rod (6) is connected to the side suction cup (8); the slider (2) is connected to the slide rod (6) on the left swing mechanism and the right swing mechanism through a guide block (10); the slider (2) moves to the left or right, driving the shift rod (7) to move outward or inward, thereby driving the side suction cups (8) on the left swing mechanism and the right swing mechanism to swing outward or inward.

3. A jig for testing the bending resistance of foil according to claim 2, characterized in that: The shifting rod (7) is connected to the workbench (1) via a shifting block (11).

4. A method for detecting a jig for detecting the bending resistance of foil according to claim 2, characterized in that: The steps include: a. Cut the foil to be tested into square foils, and ensure that the square foils are intact, flat and wrinkle-free; b. Attach the square foil to the side of a cylinder with a radius of 5mm-100mm, and roll the square foil into a cylindrical shape around the side of the cylinder. Release it after 1 minute to keep the square foil in a natural bending state. c. Select a detection vertex (21) from the rolled square foil, manually press lightly on the inner side of the curved surface, and at the same time rotate the left corner (22) and the right corner (23) of the square foil outward until the left corner (22) and the right corner (23) are close together; then connect the rear part (24) of the square foil to the rear suction cup (4), and connect the left corner (22) and the right corner (23) to the side suction cups (8) on the left swing mechanism and the right swing mechanism respectively, and move the slider (2) to the left or right. The moving rod (7) is driven to move outward or inward, thereby driving the side suction cups (8) on the left swing mechanism and the right swing mechanism to swing outward or inward, so as to bend the square foil, and ensure that when the square foil is bent, the position of the detection vertex (21) remains unchanged, and at the same time, the light point of the light beam transmitter (12) faces the detection vertex (21). When the square foil is pierced, the light beam receiver (13) receives the light beam signal of the light beam transmitter (12), and the slider (2) stops moving, and the number of bends is recorded.

5. The method for detecting a jig for detecting the bending resistance of foil according to claim 4, characterized in that: The bending angle between the left corner (22) and the right corner (23) is 0°-90°.

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