Test method for antistatic cloth
The antistatic performance evaluation of antistatic fabrics should be based on the different properties of the fabric, and the test items will vary from method to method. Electrostatic testing includes testing of dangerous static power parameters, testing of static properties of materials and products, and testing of electrostatic sensitivities of flammable and explosive materials. The main parameters characterizing the electrostatic properties of materials or products are resistivity, leakage resistance, charge density and half-life, triboelectric charging voltage and half-life. The performance evaluation of anti-static cloth mainly includes resistance index, electrostatic voltage and half-life, charge surface density and other indicators, as well as simple low-precision test indicators such as suction test, Zhangfan test and adsorption metal sheet test.
Method A (half-life method, same as FZ/T01042-1996): The sample placed on the optional metal platform was discharged with a high voltage of +10 kV for 30 s, and the half-life (s) of the induced voltage was measured. This method can be used to evaluate the electrostatic attenuation characteristics of fabrics, but the contact state of the samples containing conductive fibers on the grounded metal platform cannot be controlled. The charge is quickly leaked when the conductive fibers are in good contact with the platform, and the decay rate is compared with ordinary textiles when the contact is poor. Similarly, the test results obtained by the same sample under different placement conditions are extremely different, so it is not suitable for the evaluation of antistatic properties of fabrics containing conductive fibers.
Method B (frictional electrification voltage method, basically the same as FZ/T01061-1999): 4 specimens (2 by 2 latitude, 4 cm × 8 cm) are placed on the drum, and the drum is rotated at 400 r/min. Standard cloth (nylon or polypropylene) friction, test the maximum value (V) of the sample charging voltage within 1 min. Because the sample size is too small, the distribution of conductive fibers will vary greatly with the sampling position for fabrics with embedded conductive fibers, so it is not suitable for antistatic properties of conductive fibers containing antistatic fabrics. evaluation of.
Method C (charge surface density method, which is basically the same as FZ/T01060-1999): The amount of charge measured by the Faraday cylinder after the sample is rubbed with the nylon standard cloth in a specific manner under specified conditions, and the charge surface density is obtained according to the sample size. (μC/m2). The charge surface density method is suitable for evaluating various fabrics, including the difficulty of accumulating static electricity by friction-containing fabrics. The measured results have a close correlation with the degree of ash absorption of the samples. Since the triboelectric charging between the sample and the standard cloth is realized by manual operation, the consistency of the test conditions, the accuracy and reproducibility of the test results are susceptible to the operation method.
D method (esd clothing charge method at the time of undressing): After the work clothes are rubbed against the chemical fiber underwear in a specific manner, the work clothes are taken off, and the Faraday cage is put in, and the charge amount (μC/piece) is obtained. The test object of this method is limited to clothing, but because the material of the underwear is not specified, the friction method is difficult to be consistent and lacks comparability.