NOPR Collection:

Structure and Strength-Crystallite Orientation Relationship in Native Cotton Fibres

2016-07-20T06:41:35Z

Title: Structure and Strength-Crystallite Orientation Relationship in Native Cotton Fibres Authors: Moharir, A V Abstract: Cotton fibre has a very complex structure at various levels and most of these have not been understood as yet, in spite of considerable efforts put in by innumerable workers, using various physical and allied techniques. Of these, the best efforts have been devoted to understanding the structure of cellulose, which constitutes the bulk of cotton fibre, and the relation between the strength of fibres and the orientation of cellulose crystallites to the fibre axis. In this paper, a review of the most pertinent literature on the structural aspects of cotton fibre is presented; also presented and discussed are data on the physical characteristics and strength-crystallite orientation relationship in respect of a large number of varieties belonging to the Gossypium hirsutum, Gossypium barbadense, Gossypium arboreum and Gossypium herbaceum species of cotton, grown species-wise under identical agroclimatic conditions. This compilation is expected to provide most meaningful comparison of species, varieties and fibre properties and in making a definitive choice about an orientation parameter for varietal characterization of cotton fibres for strength. Such a parameter would be a definitive aid to cotton breeders for a deterministic quality breeding programme and also to cotton fibre technologists for ensuring a uniform quality of finished products. It is concluded from the X-ray diffraction studies on varieties belonging to the four commercial species of cotton that the Hermans crystallite orientation factor is the most reliable index of strength of fibres. Varietal characterization of cotton therefore must be made on the basis of this parameter and not on the basis of 40 or 50% X-ray angles conventionally used. Page(s): 106-119

Relationship between Imperfection Count in Single and Ply Yarns

2016-07-20T06:41:18Z

Title: Relationship between Imperfection Count in Single and Ply Yarns Authors: Salhotra, K R; Ghosh, N C Abstract: The relationship between yarn unevenness of single and ply yarns is well known. In this paper, equations have been derived for relating thick places, thin places and neps in single and ply yarns. Page(s): 103-105

Application of Backward Light Scattering Interference Patterns for Calculating the Refractive Indices of Some Polymeric Fibres

2016-07-20T06:41:12Z

Title: Application of Backward Light Scattering Interference Patterns for Calculating the Refractive Indices of Some Polymeric Fibres Authors: Fouda, I M; El-Farhaty, K A; Abouzeid, M A Abstract: An experimental method to determine the refractive index of polymeric fibres is described. The method is based on an analysis of the back-scattered light of a laser beam impinging on the fibre axis. The mean parallel refractive indices, calculated by two different formulae, are in agreement with those published earlier but obtained with different techniques, namely interferometric and Becke-line methods. The results are also in good agreement with the Wilkes equation published recently. Page(s): 100-102

Evaluation of Starch and Acrylic Size

2016-07-20T06:41:05Z

Title: Evaluation of Starch and Acrylic Size Authors: Aggarwal, V K Abstract: A modified starch and a polyacrylamide-based acrylic size were evaluated for adhesive and cohesive properties. The effects of concentration of sizes paste on film formation and cohesive properties, and of concentration on add-ons and adhesive properties, for the two sizes on cotton as well as polyester fibres, were investigated. The compatibility of the two sizes for adhesive and cohesive properties on blending the two sizes in pure form was also studied. The tensile strength of the film increased with concentration, in both acrylic and starch sizes though the improvement in starch film was marginal. The average thickness of the film showed an increasing trend though it was not proportional to concentration. Increase in concentration of both the sizes resulted in a higher add-on, higher tensile strength for polyester as well as cotton rovings, but a change in blend rate did not affect the adhesive properties of the size. Page(s): 97-99