Research on wear resistance testing of automobile interior materials أداة الاختبار –

Research on wear resistance testing of automobile interior materials

The wear resistance of car seats is of concern to industry players. Synthetic leather is one of three flexible materials commonly used in modern car seat designs. It has the approximate appearance of natural leather. Due to the limited resources of natural leather, the high price and high environmental requirements during processing, major automobile manufacturers have developed synthetic leather for automobile interiors. Among them, PU coated fabric is currently the most common synthetic leather material for automobile interiors.

Wear resistance is one of the main indicators to evaluate the performance of PU synthetic leather for car seats. The current wear resistance test method of synthetic leather for seats is the wear resistance test method.sure MIE, which is mainly used. The friction method used by French car manufacturers is \"alternative two-way friction\", and the test duration can be divided into 8, 12 and 16 hours. Since this test method has the disadvantages of being time-consuming, having a single friction path and unsatisfactory friction effect, a more efficient alternative method for wear resistance testing must be found in order to get better test results.

Since the MIE abrasion resistance test and the MAR abrasion resistance test were originally used to test the linting/pilling properties of fabric, both use standard woolen fabric as friction medium, and MAR abrasion resistance test this method has very good test results in fabric lint/pilling test. For example, the MAR tester can test multiple samples at the same timetime, which helps improve testing efficiency. In addition, there is continuous low-pressure reverse friction between the sample and the friction medium, and the relative friction trajectory is the Lissajous trajectory, which increases the risk of friction anywhere on the sample. Likewise, on Friday the direction of the function is uniform. Based on the advantages of MAR wear resistance test method, this article will explore the feasibility of using MAR test method to replace MIE test method to test the wear resistance of synthetic leather for car seats.

Tests and results
The parameter used to evaluate the wear resistance of synthetic leather for car seats is the change in surface gloss of the synthetic leather caused by wear of the surface. The surface of new synthetic leather has some textures and is not smooth. After a period of friction, the textsures will gradually disappear and the surface of the material will become smoother. Use a gloss meter (Gloss Meter 60°) to measure the surface gloss of PU synthetic leather and reflect the wear degree of the PU leather surface by comparing the change in gloss before/after wear of the surface of the synthetic leather.
In order to accurately evaluate the testing effect of MIE test method and MAR test method on the wear resistance of synthetic leather for car seats, the samples used in the test have were taken from 7 types of synthetic seat leather commonly used by a renowned European automobile manufacturer. Styles, textures and properties vary to ensure test results are representative. The wear resistance of each sample was tested using two different testing methods, MIE and MAR.
MIE wear resistance test according to the Renaul standardtPSA D44 1073 (wear test of materials used in automobile interiors)The test duration is 8 hours; The MAR abrasion resistance test is carried out according to the Renault PSA D 441846 standard (textile fluffing and pilling test), and the test instrument model is the M ARTINDALE 103 (4-head type). According to the previous wear resistance test of PU synthetic leather, the mass of the weight is selected to be 1400g, the number of rubs is 3200 times (about 60 minutes), and the surface gloss value PU synthetic leather. is recorded 1600 times (approximately 30 minutes). The highest conditions meet the testing standards, that is, the temperature is 23±2℃ and the humidity is 50%±5%. Table 1 lists the specifications of the standard friction mounts used in both test methods.
Observing the entire process of wear resistance testing, there was no phenomenonis abnormal such as synthetic leather being torn, deformed or surface temperature rising sharply during testing. Figure 1 shows the results of the wear resistance test. In the figure, MAR1600 means the number of frictions is 1600 times, and MAR3200 means the number of frictions is 3200 times. Additionally, at the request of the manufacturer, sample information will not be published. The seven sample numbers are represented by Arabic numerals in the figure.
It can be seen in Figure 1 that the results of the wear resistance test. After the wear resistance test, the gloss changes of all samples were greater than zero, indicating that the surface gloss of the samples was improved to different degrees after friction. In addition, the test effect of the MAR method is obviously better than that of the MIE method, that is to say, in order to improve the efficiencyAfter the test, the difference in brightness of the sample before/after the test is obvious. No.l, No.3, No.4, No.7) or equivalent to the MIE method (No.2, No.5, No.6). This shows that using the M AR test method to test the wear resistance of PU synthetic leather can not only improve efficiency, but also provide accurate test results.
In addition, it can be seen that the surface gloss of PU synthetic leather has increased significantly during the first 1,600 times. If the test continues, the surface gloss will no longer change significantly, indicating that the wear effect of the sample surface tends to be stable. Figure 2 shows the wear resistance test results 0 to 1600 times MAR of a typical sample (No. 4). The results show that the standard number of frictions for wear resistance of PU synthetic leather can be set at 1,600 times. This allows us to gsaves time and guarantees the reliability of test results.
Looking at Figure 2 in more detail, we can see that the brightness of the sample increases rapidly before being around 400 times, and then the increasing trend slows down. Therefore, you can try 400 times as an effective observation point to quickly observe material wear. In order to demonstrate the feasibility of this conclusion, 7 samples were subjected to MAR friction tests from 0 to 400 times, and the surface gloss value of the material was recorded every 50 times (for more detailed observation of the changes in gloss of the surface of the material). during the initial period of the test), taking a value every 25 times from 0 to 100 times), the results are shown in Figure 3.
It can be seen in Figure 3 that the surface gloss of the The sample increases rapidly before 300 times, and reaches a relativ state for the first timestable between 300 and 400 times (except n°5 and n°7), which shows that it is possible to use 400 times as a reservation obsepoint to quickly observe the wear of the material.
In In short, between 0 and 400 times of friction, the surface gloss of the sample increases rapidly and the surface wears quickly. After 400 times, the surface gloss of the sample increases slowly and the wear rate slows down.
During wear resistance tests No. 5 and No. 7, it was found that the surface of the friction medium became extremely rough and significant pilling occurred, making the results of the non-representative tests. In order to resolve this issue, the friction fluid was replaced with the standard friction fluid used in the positive M test (see Table 1 for specifications), and the MAR test (0 to 400 times) was carried out for No. 5. and No. 7. It can be seen from the figure that pilling and pilling will no longer occurs on the surface of the friction medium after replacement and the testing process is stable. The wear resistance test of No. 5 and No. 7 before/after replacing the friction fluid, the results are shown in Figure 5 (the test data recording method is the same as that in Figure 3).

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