Scientists at the Hohenstein Institute have, for the first time, developed a finish for textiles that creates a sensory cooling effect.
This textile finish is based on p-menthane derivatives (agonists), such as WS-3 (N-ethyl-p-menthane-3-carboxamide) or L-menthyl lactate and icilin. These substances have the advantage that, when spread in very low concentrations on small areas of the body, they have a lasting mild cooling effect throughout their period of activity. This kind of sensory cooling textile finish was tested on different textile substrates made from natural or synthetic fibers and blends, and in concentrations of the active ingredient ranging from 0.001-1%.
In tests with volunteers, the attempts at functionalizing textiles using substances which have a sensory cooling effect produced very different sensory perceptions of the degree of coolness. The sensory perception of cold depended not only on the area of skin being treated but also on a range of other parameters such as the moisture level in the skin and the topography of the skin surface. The way the perceived cooling effect on the skin is processed and assessed depends on numerous external and internal factors, and is therefore subjective; i.e., each volunteer perceives the cooling effect in their own quite specific, individual way.
The researchers were able to make new findings about the substance sensitivity of specific areas of the skin (e.g., the cleavage, underarm, soles of the feet). The project also showed that sensory cooling textiles are effective in textiles worn close to the skin, but are unsuitable for loosely cut clothing that is not in direct contact with the body.
The scientists at Hohenstein were able to show that applying a finish containing sensory cooling substances (WS-3 or menthyl lactate) would be feasible for SMEs.