الوصف: |
Conductive fabrics are textile materials, which in their construction partially or completely contain threads of electrically conductive yarn and consequently can conduct electricity. Conductive yarns contain conductive materials such as carbon, silver, stainless steel, nickel, copper, etc. and can be used as filaments, staple mixtures or electrically conductive threads obtained by mixing with conductive polymers, i.e., electrically conductive fillers such as carbon and metal particles. The application of electrically conductive fabrics is wide, e.g. for antistatic clothing preventing electrostatic discharge (for employees at gas stations and gas platforms), in medicine, space research, etc. In this paper, the influence of the presence (density) and position (arrangement) of conductive yarns, made of filament carbon bi-component yarn (Negastat), fineness 39 dtex, twisted with polyester staple single yarn, on the charge decay of the woven fabric was investigated. Seven fabric samples were woven in ripstop weave on a laboratory weaving machine. The base raw material for all samples were aramid warp and weft yarn. Conductive threads plied with bi-component carbon filament yarns were woven into the construction of the samples in different positions of the rib weave segments. Samples 1 to 4 contain carbon threads in rib weave segments of the weft. The carbon threads are arranged in various densities, while samples 5 to 7 contain carbon threads in warp and weft (grid form) in various densities. Tests of basic characteristics of fabrics and measurement of electrical charge decay were performed on all samples. The results of tested samples showed that the presence and position of carbon bi-component filaments affect the electric shielding factor. In general, a higher proportion of bi-component fibre per woven fabric unit area will give higher values of the shielding factor. Furthermore, samples containing carbon filaments in the warp and weft (samples 5 to 7) have a higher shielding effect compared to samples having carbon yarns only in the weft direction (samples 1 to 4). The reason for this is the grid shaped structure that allows a greater degree of freedom in the movement of electrons within the woven fabric. |