Mechanical Discrimination of Hairy Fabrics from Neurosensorial Criteria

Abstract

Fabrics with more and more elaborate tactile properties are available on the textile market. However the specifications of the textile products do not feature their touch because this can not be measured precisely and objectively enough. Some measurement methods of the mechanical properties involved in tactile feeling have been developed. Nevertheless, a purely mechanical approach is not sufficient. Therefore, the human being was utilized as a touch sensor. The tactile afferent [i.e. conveyed to the central nervous system, centripetal] messages elicited by the mechanoreceptors of the skin in response to textile stimuli and which were propagated along the sensitive nervous fibers up to the brain were studied. These messages were recorded on conscious human individuals, by a method named microneurography. The aim of this study was to use the neurosensory results in order to improve the mechanical measurement methods for the characterization of the surface state of fabrics. The samples tested had undergone different emery finishing processes. The preliminary results of the microneurographic study highlight the importance of taking account of the effect along/against the main direction of the hairiness. In fact, the discrimination of different hairy fabrics by cutaneous mechanoreceptors is only achieved when the fabrics stroke the skin against the main direction of the hairiness. A friction device developed by the co-authors was modified in term of signal processing in order to measure the surface along and against the main direction of the hairiness separately. Moreover, the probe was improved in order to separate the mechanical behavior information on hairiness from the roughness information. The results obtained with this new method were compared with results obtained using the surface tester of the KES-F.