Whether it is nurses in their uniforms, sportsmen in their training gear or anyone wearing light-coloured swimming trunks, everyone knows the problem of white garments which all too often reveal more than you want—either of yourself or of any white or dark underwear underneath. For things like scaffolding covers or trade fair exhibits, too, the transparency of textiles is an important factor.
Researchers at the Hohenstein Institute in Bönnigheim, Germany, in cooperation with their project partner Eschler Textil, are working hard on finding a way of being able to give an objective evaluation of the specific degree of transparency or opacity of textiles and also control it. In this “hands-on” research using volunteers with different skin types, existing measuring methods already used in paper-making are to be transferred to real-life conditions in the textile industry. Participants in the optical trials assessed the transparency of a piece of white test fabric by means of a questionnaire. The findings from the tests will then be confirmed using actual skin types and finally converted into an objective method for classifying transparency.
As well as evaluating degrees of opacity, the project will also come up with guidelines for controlling transparency by the thickness and composition of the yarn. This will mean that in the future the required degree of opacity will be able to be defined and applied/set, even as textile materials are being constructed. In a further stage of the project, researchers will also investigate the effect of external influences such as wetness on the transparency of textile materials.