Test method for cross peel performance of pet tab film

Abstract

The application belongs to the technical field of tab film peeling performance test, and particularly relates to a cross peeling performance test method of PET tab film, which comprises the following steps: S1, cutting a PET tab film sample to obtain a sample and marking the inner face and the outer face; S2, setting the outer face of the sample upward, fixing the outer PP layer and then pulling the middle PET layer to separate; S3, setting the inner face of the sample after the step S2 peeling toward upward, fixing the inner PP layer and then pulling the middle PET layer to separate; S4, setting the pulling force parameter of the pulling machine as D; S5, clamping the outer PP layer by the pulling machine to obtain the average peeling force D1 of the outer PP layer within the data reading range; S6, clamping the inner PP layer by the pulling machine to obtain the average peeling force D2 of the inner PP layer within the data reading range; S7, observing the layering damage of the sample after peeling of the two faces, and the sample data without damage enters the step S8; S8, comparing D1 and D2 with D respectively, and the peeling force is normal when D1 and D2 are both greater than D, and the peeling force is abnormal when any one does not satisfy the condition.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tab film peeling performance test, and particularly relates to a cross peeling performance test method for a PET tab film. BACKGROUND

[0002] The tab film is a component of a lithium ion battery product, and is a contact point during charging and discharging. The performance and quality of the tab film directly affect the safety and stability of the battery. Therefore, strict quality control and testing need to be performed on the tab film during battery production. The PET tab film is a three-layer film composed of different materials of PET and PP layers. The PET tab film is stretched and layered. The currently used method is to slowly separate the PP layer and the middle PET layer by pulling the two sides of the scratch with both hands. Since the elongation rates of the PP layer and the PET layer are different, it is difficult to perform synchronous stretching, and the phenomenon of breakage occurs at a certain distance, so that the peeling performance cannot be obtained.

[0003] Therefore, it is a technical problem to be solved in the art to provide a test method that can accurately characterize the peeling performance of the PET tab film.

[0004] It should be noted that the above information disclosed in the background section is only used to understand the background of the present application, and therefore, the above description is not considered to constitute information of the prior art. SUMMARY

[0005] The embodiments of the present disclosure at least provide a cross peeling performance test method for a PET tab film.

[0006] In a first aspect, the embodiments of the present disclosure provide a cross-peeling performance test method for a PET tab film, comprising the following steps: step S1, cutting a PET tab film sample to obtain a sample and marking the inner and outer surfaces; step S2, setting the outer surface of the sample upward, lightly scratching a first shallow mark on one side between the outer surface PP layer and the middle PET layer of the sample, and smearing the first shallow mark with a solvent to expand the first shallow mark into a first opening, then fixing the outer surface PP layer and pulling the middle PET layer to separate; step S3, setting the inner surface of the sample after step S2 upward, lightly scratching a second shallow mark on one side between the inner surface PP layer and the middle PET layer of the sample, the first shallow mark and the second shallow mark being located on the two sides of the sample respectively, smearing the second shallow mark with a solvent to expand the second shallow mark into a second opening, then fixing the inner surface PP layer and pulling the middle PET layer to separate; step S4, setting the pulling force parameter of a pulling machine as D; step S5, clamping the outer surface PP layer with the pulling machine to obtain the average peeling force D1 of the outer surface PP layer within the data reading range; step S6, clamping the inner surface PP layer with the pulling machine to obtain the average peeling force D2 of the inner surface PP layer within the data reading range; step S7, observing the delamination damage of the sample after peeling on both sides, and the sample data without damage enters step S8; step S8, comparing D1 and D2 with D respectively, and when both D1 and D2 are greater than D, the peeling force is normal, and when either one does not satisfy the condition, the peeling force is not normal.

[0007] In an optional embodiment, the size of the sample in step S1 is 15mm*120mm.

[0008] In an optional embodiment, the depth of the first shallow mark and the second shallow mark ranges from 10mm to 15mm, and the depth of the first opening and the second opening ranges from 12mm to 20mm.

[0009] In an optional embodiment, the separation distance in steps S2 and S3 is 1cm to 5cm.

[0010] In an optional embodiment, the fixing method of the outer surface PP layer and the inner surface PP layer in steps S2 and S3 comprises abutting with a steel ruler, wherein the abutting angle of the steel ruler is 130° to 150°, and the contact width is 10mm to 20mm.

[0011] In an optional embodiment, the average value of the pulling force parameter D in step S4 is 5N.

[0012] In an optional embodiment, the setting parameters in step S4 further comprise the distance between the upper and lower clamps, the peeling speed, the test change point distance, and the data reading range.

[0013] In an optional embodiment, the distance between the upper and lower clamps is set to range from 3cm to 5cm.

[0014] In an alternative embodiment, the peeling speed is set to a range of 50-200 mm / min.

[0015] In an alternative embodiment, the data reading range is 15-55 mm; and the test change point distance from the initial point of the tensile testing machine is in a range of 60-80 mm.

[0016] The PET tab film cross peeling performance test method has the advantages that the cross peeling of the double-sided PP layer is used to realize the effect of obtaining the peeling force performance of the inner and outer PP layers on the same tab film sample, the segmented opening is used to ensure the integrity of the film layer, and the most real performance of the PET tab film can be reflected.

[0017] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the application. The objects and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0018] In order to make the above-mentioned objects, characteristics and advantages of the present application more obvious and easy to understand, the following preferred embodiments are specifically described below, and the accompanying drawings are described in detail as follows. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0020] Figure 1 A peeling schematic diagram of a PET tab film cross peeling performance test method provided by the embodiment of the present disclosure;

[0021] Figure 2 A physical diagram of inner and outer PP cross peeling (A inner, A outer) and single-sided PP peeling (D inner) provided by the embodiment of the present disclosure.

[0022] In the drawings:

[0023] 1, outer PP layer; 2, middle PET layer; 3, inner PP layer. DETAILED DESCRIPTION

[0024] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the scope of the present application.

[0025] As used herein, the phrases "in one embodiment", "according to one embodiment", "in some embodiments", and the like, generally mean the fact that a particular feature, structure, or characteristic described after the phrase can be included in at least one embodiment of the present disclosure. Therefore, the particular feature, structure, or characteristic can be included in more than one embodiment of the present disclosure, so that these phrases do not necessarily refer to the same embodiment. As used herein, the terms "example", "exemplary", and the like, are used as an example, instance, or illustration. Any implementation, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms "example", "exemplary", and the like, is intended to present concepts in a concrete manner.

[0026] In this document, example embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings, as used herein, expressions such as "at least one of", when following a list of elements, modify the entire list of elements and not individual elements of the list. For example, the expression "at least one of a, b, and c" should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0027] The terminology used herein is for the purpose of describing particular example configurations only and is not intended to be limiting. As used herein, the singular articles "a", "an", and "the" can be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "including", and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order in which they are discussed or illustrated, unless specifically identified as an order of performance. Additional or alternative steps can be employed.

[0028] Some embodiments of the present application will be described in detail below. The embodiments described below and the features in the embodiments can be combined with each other without conflict.

[0029] The embodiment of the present disclosure provides a cross-peeling performance test method of a PET tab film, which comprises the following steps: step S1, cutting a PET tab film to obtain a sample, and marking the inner surface and the outer surface; step S2, setting the outer surface of the sample upward, lightly scratching a first shallow mark on one side between the outer surface PP layer and the middle PET layer of the sample, smearing the first shallow mark with a solvent, expanding the first shallow mark into a first opening, fixing the outer surface PP layer, and then pulling the middle PET layer to separate; step S3, setting the inner surface of the sample after step S2 upward, lightly scratching a second shallow mark on one side between the inner surface PP layer and the middle PET layer of the sample, the first shallow mark and the second shallow mark being respectively located on two sides of the sample, smearing the second shallow mark with a solvent, expanding the second shallow mark into a second opening, fixing the inner surface PP layer, and then pulling the middle PET layer to separate; step S4, setting the pulling force parameter of a pulling machine as D; step S5, clamping the outer surface PP layer with the pulling machine to obtain the average peeling force D1 of the outer surface PP layer in the data reading range; step S6, clamping the inner surface PP layer with the pulling machine to obtain the average peeling force D2 of the inner surface PP layer in the data reading range; step S7, observing the delamination damage of the sample after peeling on both sides, and the sample data without damage enters step S8; step S8, comparing D1 and D2 with D respectively, and when both D1 and D2 are greater than D, the peeling force is normal, and when any one does not satisfy the condition, the peeling force is not normal.

[0030] In an optional embodiment, the size of the sample in step S1 is 15mm*120mm.

[0031] In an optional embodiment, the depth of the first shallow mark and the second shallow mark ranges from 10mm to 15mm; the depth of the first opening and the second opening ranges from 12mm to 20mm, the scratch is smeared with alcohol after being obtained, and the opening is cleaned after 3-5s, so as to provide sufficient clamping area for the pulling machine.

[0032] In an optional embodiment, the separation distance in steps S2 and S3 is 1-5cm.

[0033] In an optional embodiment, the fixing mode of the outer surface PP layer and the inner surface PP layer in steps S2 and S3 comprises abutting with a steel ruler; wherein the abutting angle of the steel ruler is 130-150°, the contact width is 10-20mm, and the setting of the steel ruler can ensure that the PP layer cannot move, and the steel ruler needs to be followed into the opening as the opening increases.

[0034] In an optional embodiment, the average value of the pulling force parameter D in step S4 is 5N.

[0035] In an optional embodiment, the setting parameter in step S4 further comprises the distance between the upper clamp and the lower clamp, the peeling speed, the test change point distance and the data reading range.

[0036] In an alternative embodiment, the setting range of the distance between the upper and lower clamps is 3-5 cm.

[0037] In an alternative embodiment, the setting range of the peeling speed is 50-200 mm / min.

[0038] In an alternative embodiment, the data reading range is 15-55 mm; and the distance between the test change point and the initial point of the tensile testing machine is 60-80 mm.

[0039] Please refer to Figure 1 As shown in Figure 1 the cross-peeling performance test method of the PET tab film, comprising the following steps:

[0040] Step S1: cutting the sample to 15 mm*120 mm, and writing the inner and outer surfaces and batch number on the cut sample;

[0041] Step S2, the outer surface of the sample is upward, and a knife is gently drawn on the right edge position of the outer surface PP layer of the sample without damaging the middle layer PET. A little alcohol is applied at the scratch position, and the outer PP layer and the middle PET layer are slowly separated by pulling the two sides of the scratch with both hands. Then, the outer PP layer is prevented from moving by placing a steel ruler against it, and the PET composite layer is slowly separated by using uniform force. The steel ruler is moved forward to resist every time the PET composite layer is separated by a certain distance, and the PET composite layer is slowly separated again by using uniform force.

[0042] Step S3, the sample peeled in step S2 is turned over with the inner surface upward, a knife is gently drawn on the left edge position of the inner surface PP layer of the sample without damaging the middle layer PET, a little alcohol is applied at the scratch position, and the inner PP layer and the middle PET layer are slowly separated by pulling the two sides of the scratch with both hands. Then, the inner PP layer is prevented from moving by placing a steel ruler against it, and the PET composite layer is slowly separated by using uniform force. The steel ruler is moved forward to resist every time the PET composite layer is separated by a certain distance, and the PET composite layer is slowly separated again by using uniform force.

[0043] Step S4, setting parameters of the tensile testing machine include the distance between the upper and lower clamps of 3 cm, the peeling speed of 100 mm / min, the test change point of 65 mm, and the data reading range of 15-55 mm;

[0044] Step S5, before clamping the sample, the middle layer PET faces oneself, and the upper clamp and the lower clamp of the tensile testing machine are clamped on the peeled surface of S2, respectively. During the peeling process, whether the sample is delaminated or damaged is observed, and the average value D1 of the data reading range is recorded after the peeling is completed.

[0045] Step S6, the sample front intermediate layer PET face to yourself, in the tension machine on the clamp and the lower clamp respectively S3 stripping surface, observe the sample during the stripping process without delamination and damage, record the data reading range average value D2 after stripping is completed;

[0046] Step S7, 2 face PP layer stripping is completed after observing the sample without delamination and damage is the sample test qualified;

[0047] Step S8, compare D1, D2 and the size of the set value D, D1, D2>D stripping force is normal, D1, D2<D stripping force is abnormal, any does not meet the normal stripping force.

[0048] Specifically, the knife in the sample PP layer distance edge 15mm position lightly draw a knife, a little alcohol is applied in the scratch position, 3 seconds after the alcohol is wiped clean, the delamination is peeled off the mouth, the hands are respectively lightly pulled on both sides of the scratch to make the PP layer and the intermediate PET layer slowly separate 2mm, the delamination is carried out from the PP layer and the PET bonding, the steel ruler is resisted on the PP layer 2mm above to prevent it from moving, and the PET composite layer is slowly separated 3cm with uniform force.

[0049] Specifically, the data reading range average value D=5N.

[0050] Specifically, the PET face to yourself is to observe the state of the stripping without delamination and damage at any time, to judge the accuracy of the stripping force.

[0051] Specifically, the PET lug film is tested by using the technical solution, and the inner and outer surfaces of each sample are peeled off, and the batch numbers are respectively marked as A, B and C. The test results of the inner and outer PP layers are A, B, C, A, B, C, and the test results are shown in the following table 1.

[0052] Table 1, the test results of the inner and outer PP cross stripping

[0053]

[0054] Please refer to Figure 2 The upper side, as Figure 2 The A inner and A outer are not broken after the inner and outer PP cross stripping.

[0055] Specifically, the results obtained by the embodiment are as follows: the 2 face PP layer can be cross stripped on a sample, the inner and outer stripping forces of A, B and C samples are different, the wrong PP surface can be effectively prevented, and the stripping state of the sample can be observed.

[0056] PET lug film is subjected to single surface peeling test, each sample is subjected to single strip single surface PP layer peeling, and each sample is respectively marked as D, F, and G. The test results of the inner and outer PP layers are as shown in Table 2.

[0057] Table 2. Single surface PP peeling test results

[0058]

[0059] Please refer to Figure 2 lower, as Figure 2 shown, the lug film appears warping after single surface PP peeling, and the complete peeling is more difficult than the inner and outer PP cross peeling.

[0060] Specifically, the results obtained by the embodiment are as follows: from the data, it can be seen that the single surface PP layer peeling, since the inner and outer PP layer peeling are separate samples, the peeling force will be consistent, and the samples peeling the inner and outer surfaces are not at one position, and cannot actually reflect the data.

[0061] In summary, the cross peeling performance test method of the PET lug film realizes the effect of obtaining the inner and outer PP layer peeling force performance on the same lug film sample by adopting the double surface PP layer cross peeling, and adopts the segmented opening to ensure the integrity of the film layer, and the most real performance of the PET lug film can be reflected.

[0062] With the above ideal embodiments according to the present application as inspiration, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the contents of the specification, and must be determined according to the scope of the claims.

Claims

1. A cross-peeling performance testing method for PET tab film, characterized in that: The steps include: Step S1, cutting the PET tab film to obtain a sample, and marking the inner and outer surfaces; Step S2, setting the outer surface of the sample upward, lightly scratching a first shallow mark on one side of the sample between the outer PP layer and the middle PET layer, smearing the first shallow mark with a solvent, expanding the first shallow mark into a first opening, fixing the outer PP layer and pulling the middle PET layer to separate; Step S3, with the inner surface of the sample peeled in step S2 facing upward, lightly scratch a second shallow mark on one side of the inner surface of the sample between the PP layer and the middle PET layer, with the first shallow mark and the second shallow mark being located on both sides of the sample, respectively. The second shallow mark is smeared with a solvent and enlarged to form a second opening. After fixing the inner surface PP layer, the middle PET layer is pulled to separate the sample; Step S4, setting the tension parameter of the tensile testing machine to D; Step S5, clamping the outer PP layer with a tensile testing machine to obtain the average peeling force D1 of the outer PP layer within the data reading range; Step S6, clamping the inner PP layer with a tensile testing machine to obtain an average peeling force D2 of the inner PP layer within the data reading range; Step S7, observing the delamination and damage of the sample after peeling both sides, and the data of the sample without damage proceeds to step S8; Step S8 , respectively comparing D1 and D2 with D. If both D1 and D2 are greater than D, the peeling force is normal; if either one is not satisfied, the peeling force is abnormal.

2. The cross-peeling performance testing method of the PET tab film according to claim 1, wherein: The size of the sample in step S1 is 15 mm*120 mm.

3. The cross-peeling performance testing method of the PET tab film according to claim 1, wherein: The depth of the first shallow mark and the second shallow mark ranges from 10 to 15 mm; The depth of the first opening and the second opening ranges from 12 mm to 20 mm.

4. The cross-peeling performance testing method of the PET tab film according to claim 1, wherein: The separation distance in steps S2 and S3 is 1-5 cm.

5. The cross-peeling performance testing method of the PET tab film according to claim 1, wherein: The method of fixing the outer PP layer and the inner PP layer in steps S2 and S3 includes using a steel ruler to hold them; The contact angle of the steel ruler is 130-150°, and the contact width is 10-20 mm.

6. The cross-peeling performance testing method of the PET tab film according to claim 1, wherein: The average value of the tension parameter D in step S4 is 5N.

7. The cross-peeling performance testing method of the PET tab film according to claim 1, wherein: The parameters set in step S4 also include the distance between the upper and lower clamps, the peeling speed, the test change point distance and the data reading range.

8. The cross-peeling performance testing method of the PET tab film according to claim 7, wherein: The setting range of the distance between the upper and lower clamps is 3-5 cm.

9. The cross-peeling performance testing method of the PET tab film according to claim 7, wherein: The peeling speed is set in the range of 50-200 mm / min.

10. The cross-peeling performance testing method of the PET tab film according to claim 7, wherein: The data reading range is 15-55mm; The distance between the test change point and the initial point of the tensile testing machine is in the range of 60-80 mm.

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