The AATCC 42 standard test method is used to evaluate the waterproof performance of fabrics under the impact of water flow. This test measures the ability of water to penetrate into the interior of the fabric by simulating the impact of water flow on the surface of the fabric. During the test, the fabric sample is exposed to a certain water flow pressure, and its waterproof performance is evaluated by measuring the amount of water that penetrates the fabric. AATCC 42 is mainly used to detect the performance of waterproof fabrics such as outdoor clothing, rain gear, etc., especially in the face of sudden water flow Impact. This method provides a reliable standard for products, helping manufacturers to evaluate the waterproof rating of fabrics, ensuring their effectiveness and durability in practical applications.