Combination of reaction of nylon 6 fiber with cyanuric chloride and subsequent reaction with chitosan gave nylon 6 fiber bonding chitosan chemically. Especially, the latter reaction improved not only the hygroscopicity but also dyeing ability for reactive dyes. Furthermore, when a one-pot method using cationic surfactant LTAC was also investigated, above two reactions could proceed simultaneously and obtained nylon 6 fiber showed the highest hygroscopicity in this work.
Periodic necking of micrometer order were generated in polyethylene terephthalate filaments by the crazing method which used tensile stress together with bending stress. PET filament passed to a bending point at a sharp blade (processing edge) under the constant tension. Cycles of the stress concentration and the relaxation were occurred at a pointed end of the processing edge, automatically. The morphology of periodic necking areas depended on the processing angle of bend at the point of the processing edge and the processing stress. Necked PET filament consisted of the necking length of 39-72 μm and the standard deviation of 2.8-6.9 μm for the processing stress of 27-32 MPa and the processing angle of 120 deg. Ratio of generated necking length per non-necking length was 0.2-1.8 (Processing angle: 136 deg.). Although PET filaments of the draw ratio 1.0 and 2.5 formed the periodic necking, those of the draw ratio 4.8 were drawn without the periodic necking. Almost conventional functional fibers were characteristic fibers in a cross sectional shape except thick and thin yarn, however, these periodic micro-necking PET fibers have specific shape in a fiber axis direction.
Awa shijira fabric was compared with plain fabric to emphasize its characteristics due to crepe. Results show: 1) Awa shijira fabric did not easily tear in a natural line of fabric in testing of warp tearing strength, but plain fabric tore in testing of warp tearing strength. 2) Thread intersection was less by rib weave in Awa shijira fabric, so warp breaking strength, warp extension percentage, and surface abrasion resistance of Awa shijira fabric was clearly less than those of plain fabric. 3) Compressibility ratio of Awa shijira fabric was more than that of plain fabric. 4) Thickness of Awa shijira fabric was more than that of plain fabric under lighter load and all fabric thickness was similar under heavier load. 5) Awa shijira fabric had bulkiness because of crepe produced by rib weave, so water absorption and drying property of Awa shijira fabric was more than that of plain fabric.
The polyurethane composites filled with waste fabrics obtained from apparel industries were prepared. Sodium lignosulfonate (LS) was dissolved in polyethylene glycol (PEG) and the above polyol system was mixed with industrial waste fabrics. Filler content was varied from 60 to 80 % to total mass. Fracture surface of composites was observed by scanning electron microscopy. Thermal diffusitivity was calculated assuming diffusion occurs one dimensionally. Calculated values were filler 80%; 2.8x10-8 m2/s, 70%;4.8x10-8 m2/s, and 60% ; 6.5x10-8 m2/s, respectively. It is concluded that waste fabric has a potential to utilize as a filler of composites designed for insulators.