NOPR Collection:

Tensile properties and meso-scale mechanism of multi-axial warp-knitted fabrics of various structural designs

2014-06-01T00:00:00Z

Title: Tensile properties and meso-scale mechanism of multi-axial warp-knitted fabrics of various structural designs Authors: Gao, Zhe; Ma, Pibo; Jiang, Gaoming; Miao, Xuhong Abstract: Tensile properties tests of three kinds of multi-axial warp-knitted fabric, namely triaxial fabrics (-45^o/90^o /+45^o and -45^o /0^o /+45^o) and quadraxial fabric (-45^o /90^o /+45^o /0^o) have been studied along the orientations of 0^o, 45^o and 90^o. Stress-strain curves are obtained. The whole tension processing has been observed through high-speed camera and the series of images is picked up to analyze the meso-scale mechanism of the extension and displacement of tows on oriented layers. The results indicate that the tensile properties of MWK fabric are closely related to the orientations of the layers, and stitching yarns incarnate significant effects on deformation procedures of fabrics. Page(s): 122-129

Numerical modeling of bagging behavior of plain weft knitted fabric using finite element method

2014-06-01T00:00:00Z

Title: Numerical modeling of bagging behavior of plain weft knitted fabric using finite element method Authors: Karimian, Mitra; Hasani, Hossein; Ajeli, Saeed Abstract: This study focuses on the applicability of finite element method to analyze the bagging behavior of plain single jersey weft knitted fabrics in the term of bagging resistance. The findings show that the numerical modeling of the bagging resistance of the plain knitted fabric using solid elements and yarn transverse Isotropic properties has good agreement with experimental values. Page(s): 204-208

Effect of solvent concentration on morphology of electrospun Bombyx mori silk

2014-06-01T00:00:00Z

Title: Effect of solvent concentration on morphology of electrospun Bombyx mori silk Authors: Kamalha, E; Zheng, Y S; Zeng, Y C; Mwasiagi, J I Abstract: Effect of solvent (LiBr and CaCl₂:methanol:water::1:2:8) concentration on the morphology of ectrospun Bombyx mori silk has been studied. Scanning electron microscopy is used to elucidate the appearance and diameter of the nanofibres. Concentrations of solvents in the range of 25-30% are found to yield fibres with fewer beads, and a better distribution of diameter. At lower concentrations, the fibres are found scattered and more discontinuous, although they appear finer as compared to the fibres produced using higher solvent concentration. The two solvents are found to yield similar results. Page(s): 201-203

Studies on convergence point of the multi-strand yarn spinning

2014-06-01T00:00:00Z

Title: Studies on convergence point of the multi-strand yarn spinning Authors: Liu, Xinjin; Su, Xuzhong Abstract: In this study, convergence point of multi-strand yarn spinning has been investigated. Firstly, the complete convergence point state is studied for two-strand yarn spinning. Then, one condition such that two strands are kept symmetric on the convergence point is given correspondingly. Secondly, a system of the equations governing the general multi-strand yarn spinning with strands is presented by introducing a series of virtual intermediate variables. After eliminating the intermediate variable, the partial convergence point state and of multi-strand yarn spinning is given. It is observed that the complete convergence point for two-strand yarn spinning can be determined by the densities and radius of two strands and the spun yarn. Page(s): 196-200