Silk fabrics are still dyed with ebony fruits in a traditional way at a factory in Tanchau in the southern part of Vietnam, which is the only factory in the country still producing the traditionally dyed silk fabrics. The dyeing process is repeated multiple times and takes a long time to complete. However, the final dyed fabric surface is especially smooth and glossy, and has a quite different feel and appearance to general silk fabrics. In the present study, the dyestuffs adsorbed on the fibers were observed microscopically and the mechanical properties of the dyed fabrics were evaluated in order to clarify how the dyeing process changes the fabric properties to yield the unique feel and appearance.
In order to clarify surface configurations and characteristics of hydrocarbon chain-immobilized cotton fabric, the surface configurations of the immobilized cotton single fiber were observed using a scanning electron microscope (SEM) and an amplitude modulation atomic force microscope (AM AFM). Changes in characteristics of cotton fabric and its fiber were measured on the phase mode and force curve of AM-AFM, and the coefficient of friction (MIU) and the mean deviation of MIU (MMD) of the friction tester (KES-SE). We obtain the following results: 1) The resulted AFM image of the hydrocarbon chains immobilized fibers shows that a whole of single cotton fiber surface was covered with the hydrocarbon chains.2) From the phase and adsorption images, it was found that the surface of the hydrocarbon chain-immobilized cotton fiber is a surface where the visco-elasticity and the adhesion force are largely fluctuated as compared with that of the untreated fiber. In addition, it was suggested that the fluctuation of adhesion force is related to the state of water caused by distribution and aggregation state of immobilized hydrocarbon chains. 3) MIU and MMD of the hydrocarbon chains immobilized fabric obtained by KES attaching silicon contactor are lower than that of untreated fabric.
In previous studies, it was clarified that the effectiveness of ultraviolet radiation (UV) protection on pantyhose or tights could not be achieved to its full extent on its own due to the increased porosity while being worn. The purpose of this study is to examine the UV protection efficiency on pantyhose and tights in combination with the use of sunscreen. It was found that the conduct of applying sunscreen by itself does not actually provide the indicated SPF, considering the fact that, on average, only a half of the specified amount is usually applied. However, by applying 25% of the specified amount of sunscreen in combination with the use of pantyhose, adequate UV protection efficiency was achieved with more than UPF15 in all samples. Moreover, applying 50% of the specified amount resulted in Excellent Protection with more than UPF40 in all samples. Therefore, it was clarified that the effectiveness of UV protection on sunscreen increased one grade higher when applied in combination with the use of pantyhose than in use by itself.