UV-filter based on nano-technology:
Annother textile fiber (Belfasun, Cognis) does not use conventional UV filters such as frequently encountered in sun creams and lotions, but rather tiny nano particles of zinc oxide (ZnO) that absorb UVB radiation completely and UVA radiation to 70%, with the remainder being effectively scattered.
Quantities amounting to 0.5-2% ZnO nano particles are distributed in an aqueous dispersion. For this process, Cognis uses the high-quality product NanoShield a new nanotechnological development from the USA. An especially developed binder system attaches the invisible nano particulate to the cotton fibers, providing them with an even, stable and permanent coating. The same innovative Cognis technology ensures uniform distribution of the nano particles even in the industrial-scale process (padding technique), guaranteeing reliable sun protection even in mass-produced articles.
In the first instance, Cognis is offering a hydrophilic form of the binder. With this, the fiber offers not just effective sun protection but also enhanced wear comfort thanks to good moisture transfer: perspiration is able to diffuse more easily to the outer surface of the fabric to facilitate evaporation, rather than accumulating and trickling down the surface of the skin. etc.
One of the real benefits of the fiber is its resistance to laundering. A cotton fabric treated with nano sun protection is able to withstand at least 40 household (i.e. moderate temperature) washes – which roughly corresponds to the average lifetime of a garment.