In this work, Mudar fibers (Calotropis procera) have been characterized for their physical, chemical, and tensile properties. Mudar fibers have good length, strength, uniformity, fineness, and excellent moisture absorption. The study highlights the difficulties in spinning 100% Mudar yarn. Subsequently, a 75/25 Mudar/cotton blend is successfully spun in a cotton spinning system and the results are analyzed. Smooth Mudar fibers develop convolutions when treated with 5% NaOH, which can render spinning possible with fibers treated in such a way. The yarns have enough potential in natural fiber-reinforced composites and other industrial textiles application.

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Purpose – The purpose of this paper is to elucidate the stress-strain relationships of single-jersey knitted fabrics from uniaxial tensile test followed by deformation behavior using finite element analysis. In order to elaborate the study, high, medium and low tightness knitted fabrics were selected and deformation of fabrics analyzed in course, wales and bias directions (0, 45 and 90 degrees). Design/methodology/approach – This study focussed on uni-axial tensile test of produced test samples using Instron 6021 tester and a development of single-jersey knitted loop model using Auto Desk Inventor software (ADI). The knitted fabric material properties and knitted loop model was imported to ANSYS 12.0 software. Findings – Due to structural changes the tightness and thickness of knitted fabric decreases with increase in loop length The tensile result shows maximum breaking strength at course direction (13.43 kg f/mm2 at 2.7 mm) and maximum extension at wales direction (165.77 kg f/mm2 at 3.3 mm). When the loop length increases, the elongation of fabrics increased and load carrying capacity of fabrics reduced. The Young's modulus, Poisson's ratio and shear modulus of fabrics reduced with increase in loop length. The deformation of fabrics increased with increase in loop length. The increase in loop length gives large amount of structural changes and it is due to slacking or jamming in loops and loosening in dimensions. When comparing the deformation results, the variation within the fabric is higher and structural damage little more when increasing the loop length of the fabric. Originality/value – From ANOVA test, stress and strain distribution was statistically significant among course, wales and bias directions at 95 percent confidence level. The values got from Instron test indicates that testing direction can alter its deformation. In deformation analysis, comparing both experimental and prediction, high amount of structural changes observed in wales direction. The used tetrahedral elements can be used for contact analysis with high accuracy. For non-linear problems, consistent approach was proposed which makes the sense to compare with experimental methods. The proposed model will make possible developments and the preliminary validation tests shows good agreement with experimental data.

Despite being spun at ambient temperatures and pressures the excellent tensile and elongational properties of spider silk makes it very useful. A recent insight into the wonderful spinning process of the spider throws new light on the research on fibers. This article tries to overview the research in the last decade stressing on the interesting spinning and drawing techniques of the spider and some of its tensile and thermal properties, which makes the fiber unique. The recent characterizing techniques used to investigate spider silk have been discussed in depth and the future areas of research outlined.

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