Principal component analysis (PCA) has been used in color technology over 50 years. Along these years many researches have been done to find out new usages or improve its shortcomings in different applications in color technology. One of the most difficult tasks is to find suitable basis vectors, which are able to reconstruct data accurately by the lowest dimension. In this article the effect of the lightness of the data set ( L^* ) on the color difference error in dimensionality reduction and recovery of the spectral reflectance using PCA method was studied. To be able to have a comparison all the experiments carried out by 3 basis vectors. The results show that by increasing the L^* value of the test and training data set in dimensionality reduction using PCA, the color difference error decreases. In recovery of spectral reflectance, the L^* of the training data set has no noticeable effect and the color difference error under reference illuminant is insignificant. This result can be explained by considering that, in recovery of spectral reflectance by PCA method, a metameric pair of original sample is reconstructed. Hence, the original and recovered samples almost match under reference illuminant. Although by increasing the L^* of the training data set, the ΔE value under illuminant A decreases slightly, so metamerism problem can be reduced.

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In this century, “comfort”, “safety”, “user-friendly” and “green” are key concepts. Our newly-developed arrowroot fiber assembly produced from industrial waste meets all of those requirements and more. In order to make effective use of industrial waste and reduce the amount produced, as well as to improve our daily lives, we investigated the development of novel fiber assemblies made from arrowroot by-products. At its heart are two processes: a chemical treatment to extract spinning materials from arrowroot industrial waste and a mechanical treatment for making the fiber assemblies. Finally, this is the first birth of new arrowroot fiber and fiber assembly.

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This paper described how the compression energy and the curvature radius of cylinder model influenced the clothing pressure. The rubber band pressed the cylinder with different curvature radius or compression energy and the pressure between the cylinder and the rubber band was measured by the film sensor sheet. As the results, it was found that the pressure between the cylinder and the rubber band was in inverse proportion to its curvature radius, and the relation among the pressure (P), the tensile stress (T), and the curvature radius (r) was suggested by the modified Kirk′s equation (P=KT/r + C) . The pressure of the cylinder with different compression property was related to the compression energy (WC) value of the cylinder.

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Conventional electret polypropylene nonwoven fabrics were made by corona discharging method. The both outer surfaces of the nonwoven fabrics had a lot of charge, but the inner parts of the nonwoven fabrics had poorer charge than both outer surfaces. Therefore, this paper reported the streaming electrification which was to make insulation liquid stream through the polypropylene nonwoven fabric. It was found that the both of outer surfaces and inner parts of the nonwoven fabric were uniformly charged, and also the polarization with positive and negative was confirmed by observation of dust figures. The performance of the filtration was superior to the conventional electret nonwoven fabric.

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Distributions of fiber orientation and fiber concentration in fiber suspension flows through a slit channel were measured. The suspensions used were dilute and concentrated ones. The slit channel had abrupt expansion and crank shape geometries with six L-shape corners. To visualize fibers clearly, an index-of-refraction matching method was employed, and tracer fibers having birefringence were also suspended. Upstream of the L-shape corner, the preferred angle of fibers oriented along the flow direction and the degree of orientation distributed symmetrically with respect to the centerline of the channel. After flowing around the L-shape corner, the preferred angle kept alignment to the streamlines, however, the degree of orientation became asymmetric with respect to the centerline. The asymmetric distribution was observed more clearly for the concentrated suspension. Furthermore, the fiber concentration is uniform over a width of the channel except the region adjacent to the side wall in the concentrated suspension flow, while it has a maximum near the side wall in the dilute case.

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The silk fibroin/nylon 66 blended nanofiber webs were made by the electrospinning process and investigate the effect of blend ratio on the structure and surface properties of electrospun nanofiber assemblies. T_g of silk fibroin and nylon 66 blends in DSC curves shifted to that of nylon when the nylon content increased. With the increase of silk blend ratio, the decrease of the fiber diameter was observed. The mean coefficient of friction (MIU) was measured by KES surface tester. The obvious effect of fiber diameter on MIU was not found in the fiber diameter range of 50 to 270nm. Maximum values of MIU were observed for the silk/nylon blend ratio of 50/50%.

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