Flexible acoustic absorption materials that can be absorbed some noises with extensive frequencies in various usage environments are required in the recent industry. Previously, the glass wool laminated glass fibers and the urethane foam based on the polyurethane resin have been used as sound absorption materials. However, the recyclability of glass wool and urethane foam are poor because of mineral and thermosetting resin, respectively. Additionally, it is necessary to combine an another acoustic absorption materials for the glass wool in order to absorb noises with extensive frequencies bands. Therefore, the purpose of our study is to development a novel eco-friendly absorption material which has wider range on acoustic absorption band without including an another sound adsorption materials. We suggest the new porous sound absorption material consist of the pulp fiber and the thermally expandable foaming agent which is composed of the acrylic polymer and liquid hydrocarbon. It is reported that the manufacturing process for pulp foaming based on the papermaking and the relationship between the internal structure and absorption behavior depending on the foaming time.
The purpose of this research is to clarify how cloth attributes, knowledge on clothing, sensory modality influence the sensibility evaluation of fabric respectively. We prepared 20 each group of subjects with different clothing knowledge, and conducted a sensitivity evaluation experiment with two kinds of touching methods (tactile and visual tactile) for 39 kinds of fabrics with different materials and weave structures. Factor analysis was conducted to clarify what kind of factor the subject evaluates the fabric, and multiple regression analysis was carried out to clarify what kind of mechanical properties are used as criteria for judgment. In the multiple regression analysis, each factor score was set as a target variable, and the mechanical characteristic was used as an explanatory variable. As a result, three factors of moist preference factor, thermal sensation factor, flexible factor were extracted. It was found that the moist preference factor mainly makes the cloth evaluation criteria for tensile properties, bending properties, surface properties, compression properties and cloth thickness for thermal sensation factor, and shear and bending properties for flexible factor.
Two types of atmospheric pressure plasma jet (APPJ) treatment were used to prepare the polyester fabric with asymmetric wettability, and then the wettability stability of the prepared fabric was examined. We investigated to make an asymmetric fabric by two methods using the APPJ treatments, and adopted the following method: After both sides of a polyester fabric were treated by the APPJ-coating, one side was subsequently treated by the APPJ-oxidation. The water contact angles on both sides of the prepared fabric were measured to be 150° and 20°. The hydrophobic and hydrophilic stability of both sides was excellent for 7 days. From surface analyses, the granular surface morphology of deposited SiO2 films was observed on the APPJ-coated side of the polyester fabric, which caused water repellency. Silanol groups were produced after the subsequent APPJ-oxidation, which contributed to hydrophilicity. It was confirmed by the horizontal water spreading that the polyester fabric with an asymmetric wettability was successfully prepared.
The purpose of this research is to develop a smart textile actuator for clothes. We developed a soft actuator with shape memory alloy wire by using flat knitting technology. It is capable of generating a maximum force of 0.61 N/mm and a maximum contraction of 7.8% when used for compression stockings. It was possible to increase the compression pressure from 10 hPa to 30 hPa in approximately 10 s. We also developed a soft actuator prototype of a flat knitting actuator covered by silicone sheets for a power assist suit. It has a length of 100 mm, a width of 60 mm, and a thickness of 2.3 mm. This actuator is capable of generating a maximum force of 22.7 N, which is more than twice the tension when it is 100% stretched. The data show that the soft actuator can be used for a power assist suit to prevent lumbago.