FUNCTION / Water Repellent
Water repellent fabrics

Water repellent textile is the fabric after finishing process in which the fabric is impregnated with a hydrophobic chemical solvent, also known as a "water repellent agent", to form an invisible protective layer on the fiber surface of the fabric. The fabric with this layer, the water drops can shape as beads on the surface of the fabric (similar to the dew on the lotus leaf), and slide on the surface of the fabric but not penetrating into the fibers immediately. The water drops also can be easily to shaken off. However, the effect of water repellent fabric is not equal to waterproof fabric, the water drops on water repellent fabric will penetrate into the fabric after a long period of time or pressure. So "water repellent" and "waterproof" are completely different functions!

Water Repellent Agent in Sustainable Issue
In recent years, people from all walks of life have paid close attention to Perfluoroalkyl Substance (PFOS), especially the damage to human health and the environment caused by Perfluorooctanoic Acid (PFOA) and related substances in long-chain PFOS. Fluorochemicals treatment agents are generally used for water repellent and oil repellent effects on fabrics.  If waterproof effect is required, it need to be added coating finishing on the fabrics.
The effect of water repellent and oil repellent of perfluorinated compounds is very good, and the finishing process is stable. At present, the long-chain C8 water repellent agent has been banned by many international apparel brands, and the short-chain C6 water repellent agent is used to instead of C8, but C6 water repellent agent still contains a little PFOA, if it be released will cause harm to the environment and the human body. Therefore, the fluorocarbon-free(FC-FREE) or perflourocarbon-free(PFC-Free) water repellent agent has also been launched one after another.
Fluoride-free water repellent agent (C0) has been used in the fabric production process. However, the current fluoride-free water-repellent agent on the market can't compare with the C6 water repellent agent, such as cost, laundry resistant and water repellent functions, etc. There is still space for effort in the market quality require level as 20/80  (80% water repellent effect after 20 washes).  Because of the surface energy, the FC-FREE water repellent agent has only water repellent function without oil repellent effect. The FC-FREE water repellent finished fabrics can not meet the needs of some market till now, such as the fabrics for food production worker.