How to Ensure the Antistatic Performance of Cleanroom Clothing
There are two main ways to ensure the antistatic performance of cleanroom clothing: first, selecting fabrics with excellent antistatic properties; second, ensuring the overall electrical connectivity of the garment, ensuring it is properly grounded when worn. The antistatic performance of cleanroom clothing can be evaluated from the following perspectives:
1. Examining the Antistatic Fibers in the Clothing Fabric. There are generally three methods for antistatic fabric processing:
① Finishing the fabric with an antistatic finish;
② Fiber grafting and modification to improve fabric moisture absorption, or blending and interweaving with hydrophilic fibers;
③ Blending or weaving antistatic fibers.
The first two methods work by increasing the fabric's moisture regain and hydrophilicity, while reducing its insulation properties, thereby accelerating static leakage. Therefore, their effectiveness may not be long-lasting or significant in dry environments or after repeated washings, and they are generally only used on ordinary clothing fabrics. Only the third method can effectively and sustainably address static issues in textiles, and is therefore widely used in the production of antistatic workwear. The antistatic performance of the fabric is determined by the resistance, dosage, and method of incorporation of the antistatic fiber. For a given surface area, the greater the amount of antistatic fiber added, the better the fabric's antistatic performance. Fabrics with different amounts of antistatic fiber added can be selected based on the cleanroom's electrostatic sensitivity level. Antistatic fibers are typically black or gray, so woven antistatic fibers typically appear as black stripes or a checkered pattern. To inspect the fabric, use scissors to cut along the edges of the black conductive fibers and separate them. Use a magnifying glass to observe whether there are one or more thicker fibers. Then, use a surface resistivity meter to measure the resistance of the separated conductive fibers. By removing several fibers, you can determine whether each black fiber in the fabric contains conductive fibers. Furthermore, surface-carburized antistatic fibers are not suitable for cleanroom use due to their inherent properties, so they should be carefully evaluated during inspection.
2. Determining Whether Antistatic Additives Have Been Added to Clothing Fabrics
In addition to having suboptimal and short-lasting antistatic properties, fabrics containing antistatic additives cannot be used in cleanrooms because the additives themselves are large organic compounds that can pollute the cleanroom environment. To determine if the fabric is static, use a multimeter to measure the resistance in both the warp and weft directions (be careful not to touch the black conductive fibers). If the measured resistance is less than 109Ω, it can be preliminarily determined that the fabric has been treated with an antistatic agent and is unsuitable for cleanroom clothing.
3. Check if the garment uses conductive accessories.
4. Check the resistance of the garment and fabric. Testing the resistance of cleanroom clothing is a relatively simple, feasible, and reliable method for evaluating its static performance.