Q: What are the influencing factors of fabric wear testing?
The wear test of fabric must be reasonable to determine the condition of wear test, which mainly has the choice of abrasive material, abrasive and sample pressure, friction track and speed and test environment.
(1) The choice of abrasive material. The abrasion instrument is used in a variety of abrasive materials, with different components and shapes of metal, emery, leather, plastic, rubber, brush and fabric, among which metals, emery and standard fabrics are most common. Different abrasive materials can be produced different wear characteristics, and affect the length of test time and the reproducibility of test results, so the choice of abrasive material is the key factors to determine the test effectiveness. At present, the abrasive materials selected by various wear testers are both single and easy to make changes in the test and make wear test results often incomparable and bad reproducibility.
Some abrasive materials especially the emery material to the fabric is often too intense in wear effect although it can be assured that the sample will wear out in a much shorter time than the natural life of the fabric, but the actual use of the fabric is often contact the human body, other fabrics, wood, iron, plastic, leather and other objects with repeated friction, this kind of abrasion is obvious larger than wear testing. The fibers that have been rubbed from the instrument’s worn sample fail to show the actual damage. It can be said that it is necessary to shorten the wear test time, but also to make the abrasive wear as much as possible to meet the actual role of wear and tear, this contradiction is difficult to solve. The current emphasis on the latter to ensure the appropriate sacrifice the former is appropriate, such as the choice of smaller hardness, the role of more moderate fabric or abrasive, to extend the wear test time.
2) Selection of pressure between sample and abrasive material. The pressure on the test sample and the wear test results are equal change. Generally, when the pressure is low, it is mostly the friction of the fabric surface, and its wear characteristics are closer to the actual situation, but the test takes longer time. Conversely, when the pressure is too high, the test time is too short, but the wear is too severe. The experimental results are far apart and the test results are not stable. Since the pressure in actual use is a variable and the test pressure is constant, the test pressure is best taken as the average pressure in actual use.
(3) Friction movement track and speed. The track of abrasion and sample contact friction is basically fixed track. Wear is also regular, and when the fabric is actually used, it is the irregular wear of irregular track, which is another reason about the result of wear test is inconsistent with actual use. However, if the wear trend of the instrument reflects the actual wear trend of the fabric (for example, the radical wear of the fabric is generally heavier), which helps reduce this inconsistency. Friction has dynamic load properties and the faster the friction speed, the bigger the impact. The current rapid test has a high speed phenomenon and is very different from the actual use. Too fast, on the one hand to make the wear effect too violent; on the other hand, there is a lack of buffer time and will cause slow response to the impact point of the fabric
(4) Test environment. The test results are affected by different temperature and humidity tests, and the effects on various fibers are different. Temperature on the natural fiber less affected, while the greater impact on the synthetic fibers .The effect on the synthetic fiber is greater because the initial modulus of synthetic fiber is more sensitive to temperature.
The closer the temperature is to the softening point, the larger the influence, but the influence is not obvious at normal temperature. Humidity has obvious influence on the abrasion of viscose fiber and has certain influence on nylon, but it has little influence on dacron and acrylic.