FTTS-FA-011 Water Repellent Textiles

Water repellent fabrics are processed with water repellent additives, so that water form droplet and stay on fabric surface but do not spread on fabric surface or penetrate the fabric – a phenomenon known as “the lotus effect.” The efficiency of water repellency is graded in 5 ratings. A standard test is usually performed after five home launderings with water at 40℃. To qualify as water repellent, the fabric must perform to at least rating 4 (ISO), in other words, 90 or better efficiency (AATCC). Further tests for the durability of water repellency may be performed after 20, 50 or 100 launderings at similar temperatures. Water Repellent Textiles are well-suited to the face fabrics of windbreakers or other outerwear as well as umbrella fabrics, furnishing fabrics…etc.

With current technology in Taiwan, the initial water repellency of Water Repellent Textiles reaches 100 ; having undergone 100 launderings, their water repellency still reaches 80 or above. The test method employed is AATCC 22. The Optical Contact Angle of lotus leaf is 135°; fabrics processed by regular water repellent treatments can have an Optical Contact Angle up to 130°; fabrics processed by regular “nano super water repellent” treatments can have an Optical Contact Angle up to 140°. However, if we utilize a unique nanotechnology for functional textiles to modify the surface texture of fabrics, we will be able to impart an Optical Contact Angle up to 150° to the fabrics and surpass the technical level of most foreign countries as far as water repellency is concerned.

This criterion defines the evaluation and testing of water repellency textiles. It is applicable to textiles with water-repellent finishes. However it is not intended to measure penetration of water through the textiles.