Outdoor clothing is primarily made of synthetic fibers. In dry outdoor environments, static electricity can easily accumulate, causing pilling, attracting dust and dirt, and causing static cling to the skin. If carrying precision electronic instruments such as electronic compasses, altimeters, or GPS navigators, the static electricity from the clothing can interfere with their operation, leading to errors and potentially serious consequences.
Antistatic fabrics are categorized into non-durable and durable types. Commonly used testing methods in China include the electrostatic voltage half-life method, electrostatic charge surface density, and point charge quantity. GB/T 12703, "Evaluation of Electrostatic Properties of Textiles," comprises seven parts, three of which are already implemented, with the remainder under development. GB/T 12703.1, "Evaluation of Electrostatic Properties of Textiles Part 1: Electrostatic Voltage Half-Life," works by charging the sample in a high-voltage electrostatic field until it stabilizes, then disconnecting the power supply and allowing the voltage to decay naturally through a grounded metal platform. The time required for the voltage to decay to half its initial value is measured in seconds; a smaller value indicates better antistatic performance. The standard specifies that grade A ≤ 2.0s, grade B ≤ 5.0s, and grade C ≤ 15.0s. For non-durable antistatic textiles, this requirement must be met before washing; for durable antistatic textiles, this requirement must be met both before and after washing.
GB/T12703.2, "Evaluation of Electrostatic Properties of Textiles - Part 2: Surface Charge Density," works by immersing a sample, after friction, into a Faraday cylinder to measure its surface charge density. This method effectively reflects the triboelectric charging of the fabric during actual wear. The peeling process is similar to the removal of clothing, reflecting the corona discharge capability of the fabric during charging. It is suitable for testing antistatic fabrics with conductive fibers, but the test results can be affected by human factors and the position of the tested fabric in the electrostatic potential sequence. The lower the surface charge density, the better the antistatic performance. The standard requires that for non-durable antistatic fabrics, the surface charge density before washing should not exceed 7.0 μC/m²; for durable fabrics, the surface charge density before and after washing should not exceed 7.0 μC/m². GB/T 12703.3, "Evaluation of Electrostatic Properties of Textiles - Part 3: Charge Quantity," specifies the principle of using a friction device to simulate the triboelectric charging of a sample. The sample is immersed in a Faraday cylinder, and the amount of charge is measured. The smaller the charge, the better the antistatic performance. The standard requires that for non-durable antistatic textiles, the charge quantity before washing should not exceed 0.6 μC/piece; for durable antistatic textiles, the charge quantity before and after washing should both not exceed 0.6 μC/piece.
Comparing existing national and industry standards, the evaluation indicators for different methods are different, and the results obtained using different testing methods are not comparable. The surface charge density method can better simulate the charging process of outdoor clothing during actual wear, making it a more suitable method for testing the antistatic performance of outdoor clothing.
