The silk dyeing utilising chemical oxidation of (+)-catechin was attempted in order to establish the deep dyeing at low temperature in a short time for inventing novel human- and eco-friendly dyeing. In the study, the dyeability of the new oxidation technique was compared with the mordanting method. The compounds giving Al³⁺, Cu²⁺, Fe²⁺, or Fe³⁺ ion in aqueous solution were used as mordants for the mordanting dyeing. The oxidation by the use of O₂, H₂O₂ or NaIO₄ was tried for the oxidation dyeing. The two-step treatment was performed as the oxidation dyeing, in which the first treatment is adsorption of (+)-catechin onto the silk fabric and the second one is oxidation of the adsorbed (+)-catechin by the oxidant. The results show that O₂ and H₂O₂ are not available as oxidants for the oxidation dyeing. The silk fibre is dyed brown colours by the mordanting dyeing and deep reddish brown by the oxidation dyeing with NaIO₄ at 30 °C and pH = 7.0 for 80 min of total treatment time. The dyeability of the oxidation dyeing with NaIO₄ is much higher than that of mordanting dyeing. Colour fastness obtained by the oxidation dyeing to washing is high enough in practical use.

We have investigated about the influence of cut pile carpet structures on the amount of particle dusts scattered in door by walking action. Samples were selected eleven cut pile carpets with different structures produced for the purpose of residential use. The dust for industrial testing No.15 specified by JIS Z 8901 was used as experimental particle dust. Surface pile thickness above the substrate (SPT), surface pile weight above the substrate (SPW), surface pile density (SPD), number of tufts per unit area (Nz), sectional area of fiber composed pile yarn (SAF) and constituent fiber number of pile yarn per square meter (FNY) were determined by ISO test methods or digital microscopic observation. As the experimental results, it was found that the amount of particle dusts scattered in door by walking action were quite independently of SPT, SPW, SPD and Nz which were well known as carpet structure main factor. On the other hand, the amount of particle dusts scattered in door showed strong correlations with SAF and FNY.

Protective clothing is an indispensable equipment for guards, police officers and so on. Although in Japan, the Firearms and Swords Control Law is strictly enforced, nails, ice picks, and such daily goods with sharp tips are not subjected to the law. Ordinally stab proof vests were comprised by metals, thus they are very heavy and poor at air ventilation. Recently, textile materials made of high performance fibers attract attentions. Nevertheless, during stabbing, the interlace points of warps and wefts slide off from their positions without yarn breakage. Hence, we cannot obtain products with high performance as we expected from raw material’s properties. In this paper, we discussed a leno fabric. Traditionally, they have been considered to be a thin, light, and sheer fabric for summer clothing. We have noticed that leno fabrics have a level of strength even though their lightness and high air ventilation. In leno fabrics, the intersection points of warps and wefts are locked by crossing of the paired warps. Such locking structure makes leno fabrics durable. In the experiment, air ventilation and stab resistance was tested and compared with an ordinally fabric. The results show that the air ventilation performance of the leno fabric is much higher than the ordinally fabric of similar weight. Additionally, stab properties of the leno fabric are not inferior in comparison with the ordinally fabric. Thus, we conclude that leno structure is a possible technique to design stab proof fabrics for protective clothing.

In indoor air environments, walking action raises dust particles that adhere to floor material surfaces. We used a tapping machine to investigate the amounts of dust particles raised from floor materials such as wooden floor coverings and textile floor coverings. Typical wooden floor coverings and textile floor coverings were used as samples for experiments. Results obtained using the tapping machine show that dust particles become airborne from wooden or the textile floor coverings. Although the raised dust particles diffused over time, their concentration from a textile floor covering was distinctly lower than those from a wooden floor covering. Therefore, we consider tapping machines as an effective method to estimate dust particles raised from floor coverings.

Keratin is a fibrous protein that constitutes the intermediate filaments in epithelial cells of vertebrate animals and is a chief constituent of hair, nail, horn, and beak. A key characteristic of keratin is its amino acid composition and high cysteine content that permits the formation of many disulfide bonds. These bonds maintain a firm steric structure and make the protein water-insoluble. Keratin also contains amino acid sequences such as RGD and LDV that are involved in cell adhesion and have similarities to fibronectin, which is a known cell-adhesive protein. Thus, much like fibronectin, high cell affinity is expected for keratin if it is used as a biomaterial.
In this study keratin protein extracted from wool fibers was processed into thin film and porous sponge, in order to evaluate the potential of keratin as a scaffold material. Biodegradability of keratin substrates were evaluated by enzymatic hydrolysis using several kinds of proteases. The results of these evaluations showed keratin to have suitable biodegradability for a scaffold. The keratin materials were evaluated for their biocompatibility by culturing the structures with chondrocyte. Cells attached well and grew steadily on all of the keratin scaffold structures. The rate of cell growth on keratin was equivalent to that of the control. Keratin materials were then subcutaneously implanted in rats. Chondrocyte in the keratin substrates were well grown without eliciting a major inflammatory response.

Silk has excellent biocompatibility and has been used as a surgical thread so far. Using its excellent properties, small diameter artificial blood vessels were produced by electrospinning method from silk solution, and its mechanical properties and internal structure were examined by solid ¹³C-NMR. As a result, soft nanofiber artificial blood vessels were produced by electrospinning silk sponge and biocompatible segmented polyurethane in a weight ratio of 7: 3 adjusted to HFIP at a concentration of 5wt%. Artificial blood vessel with excellent flexibility was obtained by slowly crystallizing silk nanofiber not by crystallization by immersion in methanol but by exposure to a high humidity atmosphere. Solid NMR measurement revealed that the nanofiber contained a lot of silk-I structure.

A Firefighter helmet plays an important role to protect the firefighter’s head from falling object, falls from a height and heat and flame from fire and heated smoke within a structure. A Japanese firefighter helmet is very light and comfort during their operation relative to Europe and North-America, but has problem in heat resistance of shock absorption material such as polystyrene foam because it is polymeric. Therefore, protection of polystyrene foam from heat has very important role in terms of both skin burns on head and shock protection by object and fall.
The objective of this paper is to build up the test instrument on firefighter helmet against heat, investigate the thermal resistance on current Japanese firefighter helmet. Then, a method by covering the polystyrene foam by cellulose fiber wipes was proposed and investigated its performance by number of layers of the wipes.
It has been found that both installation of cellulose fiber wipes between helmet shell and polystyrene foam has insulated heat to polystyrene foam and absorption of water by the cellulose fiber wipes which released from aluminum hydrate as fire retardant for firefighter helmet shell made time delay to increase the temperature and maintain the performance of heat insulation. It is expected that this installation of wipes has great effect to maintain shock absorption even if the helmet is exposed to heat and flame for firefighter working environment.

In Japan, many men’s college students wear HAKAMA styles in coming-of-age ceremonies. I investigated the women’s evaluation for the men’s HAKAMA style fashion in autumn 2016. I carried out the questionnaire to 200 women's college students. They lived in Kansai area and they are the third grade students. The purpose of the questionnaire is to know needs and standards about woman’s standard of evaluation in order to spread boy's HAKAMA styles. Some of women approve of boy’s wearing HAKAMA styles, but the other women do not support it. Those who agree it say that HAKAMA styles are Japanese full dresses and they can experience Japanese tradition. Those who disagree it say that HAKAMA styles do not like them and they look like proudly. Women have three standards about the evaluations of HAKAMA styles. The first standard is formal, the second is gorgeous, and the third is special. If men’s college students wear HAKAMA styles more elegantly, more women’s college students praise them.

Japan is one of the resource-rich countries in the world from the standpoint of “urban mine”, and the establishment of simple, low-cost and environment-friendly technology for noble metal recovery is the urgent issue to be solved. In this study, the nonwoven fabric which can adsorb gold ions selectively was developed using nanofiber with extremely high specific surface area as an adsorbent. The nanofiber material useful for gold ion adsorption was explored, and as a result, it was found out that nylon 6 has a great affinity for gold ions. The nanofiber nonwoven fabric was prepared by depositing nylon 6 nanofibers produced by electrospinning method. The mean diameters of nanofibers produced in this study were 143 and 206 nm at the nylon 6 concentrations of 10 and 20 wt%, respectively. The nonwoven fabric with thinner fibers has higher adsorption capacity due to larger specific surface area. The adsorption test of a mixture of Au³⁺, Cu²⁺, Al³⁺ and Fe³⁺ was also performed. As a result, only gold ions could be selectively adsorbed to the nylon 6 nanofiber nonwoven fabric. Moreover, the desorbability of gold ions adsorbed to the fabric was increased by shifting the immersion fluid to the higher pH environment.

When tsunami comes, emergency service workers usually have to wear a dry suit to rescue lives that are drifting and struggling in the tsunami. Therefore, rubble-resistant dry suit materials are in high demand. In this paper, in order to improve the penetration resistance of the dry suit materials, we attempted to introduce fiber which as a reinforcement into CR rubber. Effectiveness has been confirmed by evaluating penetration resistance and flexibility. Based on this method, we also developed a new hybrid structure with high penetration resistance against rubble.

Mechanical joints are usually and easily used for joining structural parts. However, for joining composite parts, stress concentration at the edge of circular hole of composite laminates leads local and ultimate destruction of the entire structure. Therefore, needle punching techniques were focused on to improve composite strength around open holes. Needle punch process can make handling abilities of textile fabrics by special needles for entangling fibers. By applying this technique, interlaminar properties of the composite laminates can be improved, therefore restrain of crack propagation at open holes by needle punch technique can be expected. However, effect of needle punch process on tensile properties have not been investigated.
In this study, effect of needle punch process for glass fiber chopped strand mat as a reinforcement of composite materials on tensile properties of the composites with an open hole was investigated by changing needle punch density. The tensile strength was increased and decreased with increase in needle punch density. From the crosssectional observation, dispersion of fibers by kneedle punch process was the reason to improve mechanical properties.

The disc friction false-twisting machine has an established processing process that enables it to process different types of yarns. However, its optimum processing condition is unclear, and basic data for designing a processing machine is scarce. The number of discs, disc shape, and disc material are empirically set, as the twisting mechanism is yet to be clarified. The mechanism of twisting and untwisting helps understand the relationship between yarn quality and twisting form. In addition, it is possible to optimize design, reduce cost, and improve processing efficiency in developing a processing machine. This study will examine twisting and untwisting of the disc to obtain basic data on the disc friction false-twisting machine. The picture of the yarn shape on the disc in the twisting part was collected as data. When the yarn is twisted, the apparent yarn thickness decreases and the twisting angle increases and when it is untwisted, the apparent yarn thickness increases and the twisting angle decreases. Based on these characteristics, the apparent thread thickness and twist angle as the yarn shape were measured, which showed that the twisting and untwisting position on the disc were switched. These results also showed that untwisting started in the middle of the twisting part while the yarn slipped on the disc. Therefore, it is possible to calculate the number of optimum discs required for the twisting part.