In this study, a compression creep behavior of three-dimensional fiber assembly for futon wadding use is investigated under high humidity condition, which simulates sleeping microclimate condition. Compression creep tester is used for the measurement, and humid air is supplied to the tester with high humidity air generator. Samples used are twelve kinds of staple fiber made of polyester (PET) fiber with round, w-shaped and hollow section, polytrimethyleneterephtalate (PTT) fiber, cupra-ammonium (cupra) fiber and Lyocell fiber. Results are obtained as follows.(1) Compression creep deformation ratio of regenerated fiber assembly is significantly large compared to that of synthetic fiber assembly for high and low stress.(2) The order of creep deformation ratio for the same fineness and fiber diameter is as follows. Cupra is the largest, PET with round section follows and PET with w-shaped section is the smallest for fineness of 1.4 dtex and fiber length of 38 mm. PET with hollow section is larger than PET with round section for 6.6 dtex and 51 mm(3) There is no significant difference in compression creep deformation ratio for staple fiber assembly made of same fiber material of which fineness ranges 1.3 ∼ 6. dtex and fiber length ranges 38 ∼ 51 mm.(4) Compression creep deformation ratio in high stress condition (2156 Pa) is larger than that of low stress condition (1176 Pa).(5) Compression creep behavior of staple fiber in high humidity condition is expressed as following equation.εt＝Y0 ln (vt+1)where, Y0 and v are constants derived from measurement curve.(6) Y0 is the magnitude of compression creep at a certain time, and Vini(=Y0·v) is the initial tangential rate of creep. Parameters Y0 and Vini is useful for describing compression creep behavior of synthetic and regenerated fiber assembly.

A micro-macro approach for numerical simulation of concentrated dispersion system of oblate particles was investigated. In the present approach, the computation of macro flows was coupled with the micro simulation of dynamics of dispersed particles. Oblate particles were modeled by oblate spheroids, and the interaction between particles was expressed by a Maier-Saupe type mean field potential. The motion of each particle was described by a stochastic differential equation. The Brownian configuration method was used and the orientation of particles was described as a configuration field. The time evolution of the configuration field was solved using a finite element method. In addition, both the velocity and the pressure field were solved using a finite element method. Simple shear flows and flows between parallel plates were numerically simulated to investigate the applicability of the present approach to the simulation of concentrated dispersion system of oblate particles. The computational results indicated that the present approach was able to qualitatively simulate the behavior of concentrated dispersion systems of oblate particles, such as a flat velocity profile and the flow-induced orientation of particles, and that the micro-macro simulation was available at a realistic computational cost.

In order to recycle the waste silk resource effectively, the biodegradable composite consisting of PBS matrix and silk/bamboo hybrid paper was prepared by hot compression molding. Beating treatment is adopted to modify silk fibroin and enhance the bamboo paper and the green composite, and the corresponding mechanical properties and morphologies were studied detailedly. The results showed that beating treatment could realize the fibrillation of fibroin and improve the hybrid paper′s tensile strength and elongation, and proper beating treatment to fibroin could also improve the mechanical properties of silk/bamboo hybrid paper reinforced PBS composite. The tensile, flexural and impact resistance properties of this green composite were improved remarkably compared with that of PBS control.

In this study, we tried to simulate human bodily movements to put on clothing, and succeeded to simulate the movement. This is a combination of mechanical clothing simulation and measurement of bodily movement.In the clothing simulation, cloth is assumed to be continuous elastic body and mechanically formulated. The equilibrium state of cloth is calculated by minimization of accumulated energy based on the strains and forces determined by deformation of cloth. Though to put on clothing is dynamic movements, the static calculation was iterated in the simulation because the movements here were very slow.A vest was targeted because of its simple structure. A clothing model of a vest was constructed from paper patterns of component parts. The bodily movements to put on clothing were measured by a motion capture system. A virtual human model was moved according to the measured data of the movements.First, shape of a vest in stable state hanging in the air was calculated, human body model was started to move, then the shape of the vest in stable state was calculated in every step of the movements. By the above calculation, the movements to put on clothing were reproduced with the simulation.

The long-term goal of this study is to design sportswear for the elderly. Previously, we reported dressing motion and muscle activity on young and dummy elderly persons while they are putting on four different styles of sportswear: long-sleeved, sleeveless, zippered, and zipper-less. In the part of the study reported in the present paper, we photographed their movements while they were putting on the four styles of sportswear and measured the wearing time, maximum working area, and muscle activity. Further, we investigated how the sportswear style influenced the psychological burden. From motion analysis, we found that, when the dummy elderly persons pass an arm through the sportswear at process (2), the wearing times for sleeveless sportswear were lower than those for long-sleeved sportswear. In addition, the maximum working area and %MVC (percentage maximum voluntary contraction) values for zippered sportswear were higher than those for zipper -less sportswear. When wearing the sportswear at process (3), the maximum working area and %MVC values for zipper-less sportswear were higher than those for zippered sportswear. From these results, it was concluded that the sportswear style influences wearing time, maximum working area, and muscle activity.

We investigated changes in the appearance and thickness of textile floor coverings caused by the Vettermann drum and practical use tests. Eight commercial tufted textile floor coverings were used as samples. All samples were subjected to the Vettermann drum test, and five samples were subjected to a practical use test carried out in accordance with ISO 11377. Visual assessments of changes in appearance were performed by seven experts. Thickness loss of samples was determined using a WRONZ non-destructive thickness gauge. In the case of the Vettermann drum test, the coefficient of agreement between the visually assessed grade and the thickness loss estimated using a logarithmic formula was r 2 = 0.899. We concluded that the law of Weber-Fechner could be applied to the relationship between visual assessment and thickness loss. Finally, the correlation between the thickness loss and visually assessed grade obtained after a total traffic of 100,000 people in the practical use test and that after 5,000 revolutions in the Vettermann drum test was very high (mean of correlation coefficient : rMEAN = 0.950).

So (Koto) is a traditional Japanese horizontal harp; in order to establish a measuring system for quantitatively evaluating the durability of So-strings using So-nails (Koto-zume), the authors developed a measuring apparatus. The durability of three kinds of So-string (silk, multi-polyester, mono-polyester) were determined. The apparatus used a simulated standard So-nail playing method. A So-nail was attached to the shaft of a motor and rotated at a constant speed. The So-nail played the string until it was broken. The authors defined the number of times the string broke as an indicator of the durability of the So-string and developed standard experimental conditions to compare the durability of different strings. The length, tension and play speed were 20cm, 147 N, and 180 rpm respectively. The silk, multi-polyester and mono-polyester strings broke at the times of 3267, 7450 and 11428 times, respectively.

There are various seat-type pressure sensors but there are no seats, which fulfill all the conditions such as flexibility, expandability, thinness and low cost. Then we developed a new pressure sensor using the compression property of fabric.In this report, we evaluated the respondent properties of the fabric sensor. It turned out its response time when to detect pressure is about 0.1 ms. Also it turned out that the frequency range of detection is about 30 Hz considering the strain of fabric when to pressure the fabric repeatedly. And depending on the conditions of the finished work such as sandwiching the fabric between rubber boards, the frequency range even decreases.

We propose a new method to enhance the cloth stain, such as the weak coffee stain in image. Our method is composed of two steps. At the first step, we obtain the principal component images by making the RGB components of each pixel to be uncorrelated. At this step, the texture structure is still left in the uncorrelated images, so it is difficult to recognize the stain. Then, at the second step, we reduce the texture structure by using Principal Component Analysis. We divide the uncorrelated images into the blocks, and those blocks are approximated by several principal eigen vectors which represent the texture structure. The approximation image represents the average texture structure without the cloth stain. So, the cloth stain is recognized without endeavor in the residual image which is obtained by subtracting the approximation image from the principal component image. As our method is robust for the number of observation data, we need only one color image whose size is not so big and whose resolution is not so high. The results of our experiment under different conditions show that the proposed method is effective for the image enhancement of the small weak cloth stain.

Unidirectional carbon fiber- or glass fiber- reinforced composites as structure materials have wide applications in many industries. In order to combine the advantages of these two fibers, both carbon fiber and glass fiber are employed as reinforcing elements in single unsaturated polyester resin, and hybrid composites are formed. In this study, the erosion behavior of CF/GFRP and GF/CFRP were investigated at different impact angles (15-90°) and compared with CFRP and GFRP on fiber orientation 90°. The results suggested that CF/GFRP was low erosion wear as compared to GF/CFRP. Scanning electron microscopy was used to characterize the morphology of eroded surfaces. The micrographs revealed that CF and GF were maintained their own erosion behavior in the hybrid composite materials as well in the neat FRP materials. The simple analytical approach was constructed to figure out the theoretic erosion behavior, which were compared to the experimental results. It was confirmed that the erosion behavior of the hybrid composite materials could be predicted by the proposed analytical approach.