Method for testing safety of plastic product

Abstract

The invention belongs to the technical field of plastic product performance detection, and particularly discloses a plastic product safety test method, which comprises the following steps: placing a plastic product in a test device according to an actual use environment, applying pressure to the plastic product according to a set pressure, and enabling the plastic product to be in a stressed arc state, the method comprises the following steps of: putting the plastic product into an organic solvent, enabling the organic solvent to be in contact with the surface of the stressed plastic product, enabling the surface of the plastic product to be in contact with the organic solvent, observing the change conditions of the plastic product in the states of being in contact with the organic solvent and being stressed, and confirming whether the plastic product is abnormal or not. The working state of the plastic product in a real environment can be more accurately simulated, so that a more reliable basis is provided for evaluating the safety of the plastic product, and a test result has a higher practical application value.

Description

Technical Field

[0001] The invention belongs to the technical field of plastic product performance testing, and particularly relates to a method for plastic product safety testing. Background Art

[0002] During the production process of plastic products, in order to evaluate the mechanical properties and durability of the produced plastic products under different environments and conditions, the produced plastic products need to be subjected to stress testing to ensure that the plastic products can withstand the expected loads and deformations in actual applications and improve the service life of the plastic products.

[0003] The current stress test method for plastic products is based on the medium stress cracking phenomenon. After the solvent molecules penetrate between the macromolecules of the resin, the interaction force between the molecules is reduced. Where the internal stress is large, the intermolecular force is originally weakened. After immersion in the solvent, these weakened areas are further weakened, causing cracking. Areas with small internal stress will not crack in a short time. The plastic product is completely immersed in a specific solvent (such as acetic acid, methyl ethyl ketone + acetone mixture, etc.), and the size of the internal stress is judged according to the time and degree of cracking. Different materials use different solvents. For example, ABS and PS can use kerosene and glacial acetic acid, and PC can use carbon tetrachloride.

[0004] However, since plastic products are generally used under pressure, they are prone to cracking if they come into contact with organic solvents. However, the above-mentioned stress testing method is mainly used to detect the internal stress of plastic products, rather than directly measure their performance under pressure. It is impossible to test the stress of plastic products under pressure, which reduces the reliability of plastic products. Therefore, we need to propose a plastic product safety testing method to solve the above-mentioned problems, so that the reliability of plastic products can be increased when they come into contact with organic solvents under stress according to actual usage conditions. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for testing the safety of plastic products, which can increase the reliability of the use of plastic products when they are exposed to organic solvents under stress according to actual usage conditions, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for safety testing of plastic products, comprising the following steps:

[0008] S1. Place the plastic product in the test device according to the actual use environment, and apply pressure to the plastic product according to the set pressure to make the plastic product in an arc state;

[0009] S2. bringing the organic solvent into contact with the surface of the plastic product under stress, so that the entire surface of the plastic product is in contact with the organic solvent;

[0010] S3. Observe the changes in the plastic products when they are exposed to organic solvents and under stress to confirm whether there are any abnormalities in the plastic products;

[0011] S4. When the plastic product has an abnormality, record the time when the abnormality occurred and the abnormal content data;

[0012] S5. Organize and analyze the recorded abnormal time and abnormal content data to intuitively reflect the performance changes of plastic products during the test process;

[0013] S6. Generate a test report based on the test data analysis results of the plastic product.

[0014] Preferably, in step S1, the testing device is configured as one of a universal material testing machine, a hydraulic pressure testing device, a lever-type bending testing device, and a spring-loaded testing device.

[0015] Preferably, the plastic product is configured as a plate, the material of the plastic product is configured as one of polypropylene, polyethylene and polyvinyl chloride, and the bending angle of the plastic product under stress is 15°-60°.

[0016] Preferably, when the plastic product is bent, the pressure range applied to the plastic sheet with a thickness of less than 3 mm is set to 50N-200N, and the pressure range applied to the plastic sheet with a thickness of 3mm-10mm is set to 200N-2000N.

[0017] Preferably, in step S2, the organic solvent is set to alcohol, and the alcohol is sprayed onto the surface of the plastic product by spraying, so that the surface of the plastic product is in contact with the alcohol.

[0018] Preferably, the organic solvent is set to be one of n-hexane, toluene, chloroform, dichloromethane, acetone and ethyl acetate, and the organic solvent is brought into contact with the plastic product by applying or spraying.

[0019] Preferably, in step S3, the abnormalities existing in the plastic product include surface cracking, crack extension and deformation. When confirming whether the plastic product has abnormalities, it is necessary to observe it every 15-25 minutes. If no abnormalities occur within 2-12 hours, the sample test is determined to be qualified and the test is terminated. If abnormalities occur within 2-12 hours, enter S4.

[0020] Preferably, in step S4, the abnormal content data includes the length of the crack, the degree of change of the deformation, the width of the crack and the shape of the crack.

[0021] Preferably, in step S5, the process of collating and analyzing abnormal content data is as follows:

[0022] S51. Classify and organize the data according to its nature and test purpose, and delete data that is obviously out of the normal range;

[0023] S52. Calculate relevant statistical indicators based on the data type and analysis purpose;

[0024] S53. Observe the changing trend of data over time and analyze the performance change pattern of samples during the test process;

[0025] S54. Draw a stress-time curve based on the data characteristics, and use the stress-time curve to intuitively reflect the performance changes of the sample during the test process.

[0026] Preferably, in step S6, the test report describes in detail the cracking or deformation of the plastic sample during the test process and the time and extent of the occurrence based on the data analysis results, and compares the test results with relevant standards or specifications to determine whether the plastic sample meets the quality and safety requirements. If it does not meet the quality and safety requirements, a comprehensive evaluation of the safety and reliability of the plastic sample is conducted, pointing out the risks and problems that may exist in the actual use of the plastic sample.

[0027] The method for testing the safety of plastic products proposed in the present invention has the following advantages over the prior art:

[0028] 1. The present invention applies pressure to a plastic product, placing the plastic product in a stressed arc state, then brings an organic solvent into contact with the stressed surface of the plastic product, and then observes changes in the plastic product under contact with the organic solvent and under stress to confirm whether the plastic product has any abnormalities. This test method takes into account the actual use of plastic products under pressure and contact with organic solvents, and can more accurately simulate their working conditions in a real environment, thereby providing a more reliable basis for evaluating the safety of plastic products and making the test results more valuable for practical applications.

[0029] 2. The present invention can detect in advance the problems that may arise in the actual use of plastic products, such as the risk of cracking under specific stress and solvent effects. During the production of plastic products, the product can be improved and optimized based on the test results, such as adjusting the material formula, improving the production process, etc., thereby improving the reliability of plastic products in actual use and reducing the occurrence of safety accidents such as cracking due to stress and solvent effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flowchart of the present invention;

[0031] Figure 2This is a flowchart of the present invention for organizing and analyzing abnormal content data. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] Example 1

[0034] The present invention provides Figure 1-2 A method for testing the safety of a plastic product is shown, comprising the following steps:

[0035] S1. Place the plastic product in the test device according to the actual use environment, and apply pressure to the plastic product according to the set pressure to make the plastic product in an arc state;

[0036] The testing device is configured as one of a universal material testing machine, a hydraulic pressure testing device, a lever-type bending testing device, and a spring-loaded testing device.

[0037] Among them, the universal material testing machine is mainly composed of a universal material testing host, a replaceable fixture and a controller. The universal material testing host provides power and loading capacity. The fixture is set as a flat splint or a curved splint according to the shape of the sample and the test requirements, which is used to fix plastic products. The controller is used to set and control the test parameters. The test parameters include loading speed and pressure. The plastic sample is placed in the fixture and fixed. Through the drive system of the universal material testing machine, different types of forces such as tension, compression or bending are applied to the plastic sample according to the set loading speed and pressure, so that the sample is in a specific stress state. For example, when performing a bending test, a bending fixture is used to fix both ends of the sample, and then the loading head of the testing machine is used to apply downward pressure to the middle of the sample to cause the sample to bend and deform.

[0038] The hydraulic pressure testing device is mainly composed of a hydraulic system, a pressure chamber, a sample placement platform and a sealing device. The hydraulic system is used to provide a pressure source. The pressure chamber is a closed space for accommodating samples and transmitting pressure. The sample placement platform is located in the pressure chamber and is used to place plastic products. The sealing device ensures the sealing of the pressure chamber. Place the sample on the sample placement platform, close the sealing device of the pressure chamber, start the hydraulic system, and the hydraulic oil enters the pressure chamber to gradually increase the pressure in the chamber, thereby applying uniform pressure to the sample and putting the sample in a pressurized state. The pressure parameters of the hydraulic system can be adjusted to control the pressure applied to the sample. A nozzle for spraying organic solvents is installed on the side wall of the pressure chamber to facilitate spraying the organic solvents onto plastic products.

[0039] The lever-type bending tester primarily consists of a lever mechanism, a fixed bracket, a sample support point, and a loading weight. One end of the lever mechanism is fixed to the fixed bracket, while the other end can be hung with a loading weight. The sample support point is located in the middle of the lever and serves to support the sample. To apply pressure, the sample is placed on the sample support point. Depending on the desired test pressure, a loading weight of the appropriate weight is hung from the other end of the lever. The weight of the weight is transmitted to the sample through the lever mechanism, causing the sample to bend under stress. The pressure applied to the sample can be adjusted by varying the weight of the weight.

[0040] A spring-loaded test device primarily consists of a spring, a fixed frame, a sample fixture, and an adjusting screw. The spring is mounted within the frame, fixed at one end and connected to the sample fixture at the other. The adjusting screw is used to adjust the spring's compression. The sample is secured to the sample fixture, and the adjusting screw is rotated to compress the spring. The spring's force acts on the sample, placing it under stress. By adjusting the screw's rotation, the spring's compression can be controlled, thereby adjusting the pressure applied to the sample.

[0041] The plastic product is configured as a plate, the material of the plastic product is configured as one of polypropylene, polyethylene and polyvinyl chloride, the bending angle of the plastic product under stress is 15°-60°, and the bending radius is 50-200mm.

[0042] When the plastic product is bent, the pressure range applied to the plastic sheet with a thickness of less than 3mm is set to 50N-200N, and the pressure range applied to the plastic sheet with a thickness of 3mm-10mm is set to 200N-2000N. During the bending process of the plastic product, pressure is slowly applied at a constant speed so that the plastic product gradually reaches the set bending degree.

[0043] S2. bringing the organic solvent into contact with the surface of the plastic product under stress, so that the entire surface of the plastic product is in contact with the organic solvent;

[0044] The organic solvent is set to alcohol, and the alcohol is sprayed onto the surface of the plastic product by spraying, so that the surface of the plastic product is in contact with the alcohol, so as to test the surface performance of the plastic product in an alcohol solvent environment.

[0045] S3. Observe the changes in the plastic products when they are exposed to organic solvents and under stress to confirm whether there are any abnormalities in the plastic products;

[0046] The abnormalities of the plastic product include surface cracking, crack extension and deformation. When confirming whether the plastic product has abnormalities, it is necessary to observe it every 15-25 minutes. If no abnormalities occur within 2-12 hours, the sample is judged to be qualified and the test is ended. If abnormalities occur within 2-12 hours, enter S4.

[0047] For example, within the first 2 hours, observe every 15 minutes to see if there are slight changes; from 2 hours to 12 hours, observe every 30 minutes; after 12 hours, observe every 1 hour, and record whether cracks occur and the location of the cracks, the length and speed of crack expansion, the degree of deformation (such as changes in bending angle), etc., to comprehensively evaluate the performance of plastic products when exposed to organic solvents and under stress.

[0048] S4. When an abnormality occurs in a plastic product, the time when the abnormality occurs and the abnormal content data are recorded; the abnormal content data includes the length of the crack, the degree of change in deformation, the width of the crack, and the shape of the crack, so as to facilitate a comprehensive evaluation of the performance of the plastic product when it is in contact with organic solvents and under stress.

[0049] S5. Organize and analyze the recorded abnormal time and abnormal content data to intuitively reflect the performance changes of plastic products during the test process;

[0050] The process for organizing and analyzing abnormal content data is as follows:

[0051] S51. Classify and organize the data according to its nature and test purpose, and delete data that is obviously out of the normal range;

[0052] S52. Calculate relevant statistical indicators based on the data type and analysis purpose. For example, for stress data, the average, maximum, and minimum values ​​can be calculated; for crack growth data, the average and maximum crack growth rates can be calculated. These statistical indicators can help provide a more comprehensive understanding of the data characteristics and distribution.

[0053] S53. Observe the changing trend of data over time and analyze the performance change pattern of the sample during the test process. For example, analyze the change of stress over time to determine whether the sample has stress concentration or stress relaxation in a certain period of time; observe the change of crack propagation length over time to determine the starting time, acceleration stage and stable stage of crack propagation;

[0054] S54. Draw a stress-time curve based on the data characteristics. The stress-time curve can intuitively reflect the performance changes of the sample during the test. Excel, Origin, GraphPad Prism, etc. can be used to draw the stress-time curve. These software have powerful drawing functions and can meet the drawing needs of different types of curves.

[0055] S6. Generate a test report based on the test data analysis results of the plastic product.

[0056] The test report describes in detail the cracking or deformation of the plastic sample during the test process and the time and extent of the occurrence based on the data analysis results, and compares the test results with relevant standards or specifications to determine whether the plastic sample meets the quality and safety requirements (if there are no clear standards, it can be evaluated based on industry experience or the expected use requirements of the product). If it does not meet the quality and safety requirements, a comprehensive evaluation of the safety and reliability of the plastic sample is conducted, pointing out the risks and problems that may exist in the actual use of the plastic sample, so as to facilitate the early discovery of problems that may arise in the actual use of plastic products, such as the risk of cracking under specific forces and solvents. During the production of plastic products, the product can be improved and optimized based on the test results, such as adjusting the material formula, improving the production process, etc., thereby improving the reliability of the plastic product in actual use and reducing the occurrence of safety accidents such as rupture due to stress and solvents.

[0057] Example 2

[0058] The similarities are not repeated here. The difference from Example 1 is that the organic solvent is set to one of n-hexane, toluene, chloroform, dichloromethane, acetone and ethyl acetate, and the organic solvent is contacted with the plastic product by applying or spraying. According to the material of the plastic product, the purpose of the test, and safety and environmental protection factors, a suitable organic solvent and contact method are selected for testing to improve the versatility of the test.

[0059] By applying pressure to the plastic product, placing the plastic product in a stressed arc state, and then bringing an organic solvent into contact with the stressed surface of the plastic product, the changes in the plastic product under contact with the organic solvent and under stress are observed to confirm whether the plastic product has any abnormalities. This test method takes into account the actual use of plastic products under pressure and in contact with organic solvents, and can more accurately simulate their working conditions in real environments, thereby providing a more reliable basis for evaluating the safety of plastic products and making the test results more valuable for practical applications.

[0060] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for safety testing of plastic products, characterized by: The steps include: S1. Place the plastic product in the test device according to the actual use environment, and apply pressure to the plastic product according to the set pressure to make the plastic product in an arc state; S2. bringing the organic solvent into contact with the surface of the plastic product under stress, so that the entire surface of the plastic product is in contact with the organic solvent; S3. Observe the changes in the plastic products when they are exposed to organic solvents and under stress to confirm whether there are any abnormalities in the plastic products; S4. When the plastic product has an abnormality, record the time when the abnormality occurred and the abnormal content data; S5. Organize and analyze the recorded abnormal time and abnormal content data to intuitively reflect the performance changes of plastic products during the test process; S6. Generate a test report based on the test data analysis results of the plastic product.

2. A method for safety testing of plastic products according to claim 1, characterized in that: In step S1 , the testing device is configured as one of a universal material testing machine, a hydraulic pressure testing device, a lever-type bending testing device, and a spring-loaded testing device.

3. The method for safety testing of plastic products according to claim 1, characterized in that: The plastic product is configured as a plate, the material of the plastic product is configured as one of polypropylene, polyethylene and polyvinyl chloride, and the bending angle of the plastic product under stress is 15°-60°.

4. A method for safety testing of plastic products according to claim 3, characterized in that: When the plastic product is bent, the pressure range applied to the plastic sheet with a thickness of less than 3 mm is set to 50N-200N, and the pressure range applied to the plastic sheet with a thickness of 3mm-10mm is set to 200N-2000N.

5. A method for safety testing of plastic products according to claim 4, characterized in that: In step S2, the organic solvent is set to alcohol, and the alcohol is sprayed onto the surface of the plastic product by spraying, so that the surface of the plastic product is in contact with the alcohol.

6. The method for safety testing of plastic products according to claim 4, characterized in that: The organic solvent is set to be one of n-hexane, toluene, chloroform, dichloromethane, acetone and ethyl acetate, and the organic solvent is brought into contact with the plastic product by applying or spraying.

7. The method for safety testing of plastic products according to claim 1, characterized in that: In step S3, the abnormalities of the plastic product include surface cracking, crack extension and deformation. When confirming whether the plastic product has abnormalities, it is necessary to observe it every 15-25 minutes. If no abnormalities are found within 2-12 hours, the sample is judged to be qualified and the test is terminated. If abnormalities are found within 2-12 hours, enter S4.

8. The method for safety testing of plastic products according to claim 1, characterized in that: In step S4, the abnormal content data includes the length of the crack, the degree of change in the deformation, the width of the crack and the shape of the crack.

9. The method for safety testing of plastic products according to claim 1, characterized in that: In step S5, the process of organizing and analyzing abnormal content data is as follows: S51. Classify and organize the data according to its nature and test purpose, and delete data that is obviously out of the normal range; S52. Calculate relevant statistical indicators based on the data type and analysis purpose; S53. Observe the changing trend of data over time and analyze the performance change pattern of samples during the test process; S54. Draw a stress-time curve based on the data characteristics, and use the stress-time curve to intuitively reflect the performance changes of the sample during the test process.

10. The method for safety testing of plastic products according to claim 1, characterized in that: In step S6, the test report describes in detail the cracking or deformation of the plastic sample during the test process and the time and extent of the occurrence based on the data analysis results, compares the test results with relevant standards or specifications, and determines whether the plastic sample meets the quality and safety requirements. If it does not meet the quality and safety requirements, a comprehensive evaluation of the safety and reliability of the plastic sample is conducted, and the risks and problems that may exist in the actual use of the plastic sample are pointed out.

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