AATCC 70-2015 Water Repellency: Tumble Jar Dynamic Absorption Test.
1.1 This test method is applicable to any textile fabric, which may or may not have been given a water-resistant or wa- ter-repellent finish. It measures the resis- tance of fabrics to wetting by water. It is particularly suitable for measuring the waterepellent efficacy of finishes applied to fabrics, because it subjects the treated fabrics to dynamic conditions similar to those often encountered during actual use. It is not intended for use in predicting the probable rain penetration resistance of fabrics, since it measures absorption of water into, but not through, the fabric.
1.2 The results obtained with this test method depend primarily on the resistance to wetting or water repellency of the fibers and yarns in the fabric, and not upon the construction of the fabric.
2. Principle
2.1 Preweighed specimens are tumbled in water for a fixed period of time and are reweighed after the excess water has been removed from them. The percentage increase in mass is taken as a measure of the absorption or resistance to internal wetting.
3. Terminology 3.1 absorbency, n.—the propensity of a material to take in and retain a liquid, usually water, in the pores and interstices of the material.
3.2 water repellency, n.—in textiles, the characteristic of a fiber, yarn or fabric to resist wetting.
4. Safety Precautions NOTE: These safety precautions are for information purposes only. The precautions are ancillary to the testing proce- dures and are not intended to be all inclusive. It is the user’s responsibility to use safe and proper techniques in handling materials in this test method. Manufac- turers MUST be consulted for specific details such as material safety data sheets and other manufacturer’s recommenda- tions. All OSHA standards and rules must also be consulted and followed.
4.1 Good laboratory practices should be followed. Wear safety glasses in all laboratory areas.
4.2 Observe wringer safety especially at nip points. Normal safeguards should not be removed. A foot-operated kickoff is recommended.
4.3 The manufacturer’s safety recommendations should be followed when op- erating laboratory testing equipment.AATCC 70 pdf download.