NOPR Collection:

Thermal Studies on Cellobiose in Nitrogen

2016-07-20T05:51:54Z

Title: Thermal Studies on Cellobiose in Nitrogen Authors: Jain, Rajesh K; Lal, Krishan; Bhatnagar, Hari L Abstract: TG, DTG and DTA data on the kinetics of pyrolysis of cellobiose, a basic unit of cellulose, in nitrogen atmosphere, have been processed by different methods to obtain thermodynamic parameters. The values of the energy of activation, Ea lie in the range 43-54 kcal mol^-1. However, the values of the free energy of activation for the degradation of cellobiose and cellulose are almost same, i.e. 43-44 kcal mol^-1. This indicates that the same mechanism operates for the thermal degradation of cellobiose and cellulose. IR spectra of the residues of cellobiose gave strong indications of dehydration and formation of a compound having carbonyl groups. Page(s): 55-58

Relationship between Stelometer Breaking Elongation and Fineness and Maturity

2016-07-20T05:50:10Z

Title: Relationship between Stelometer Breaking Elongation and Fineness and Maturity Authors: Makwana, D N; Munshi, V G Abstract: The relationship between breaking elongation and fineness and maturity of cotton fibres has been studied. It is found that the breaking elongation is related negatively to fineness and positively to percentage of mature fibres. A single equation relating the breaking elongation with the percentage of mature fibres and fineness has been worked out. The values of breaking elongation calculated from this equation agree fairly well with the observed values. Page(s): 52-54

Effect of Yarn Structure on Fabric Stiffness

2016-07-20T05:49:00Z

Title: Effect of Yarn Structure on Fabric Stiffness Authors: Bhargava, G S Abstract: The effect of structure of weft yarn on fabric stiffness has been investigated, keeping the warp yarn, fabric sell and weave the same. Yarns of the same resultant count, but of seven different structures, first with single Z twisted, second and third 2-ply and 3-ply single Z and folded Z twisted, fourth and fifth 2-ply and 3-ply single Z and folded S twisted, and sixth and seventh 2-ply and 3-ply without folding twist, were used. It was observed that the 2-ply yarn with folding twist opposite to single yarn exhibits maximum weft-way fabric stiffness and in general exhibits maximum stiffness. Increase in the number of plies from 2 to 3 in folded yarn lowers the warp-way and overall fabric stiffness. In the case of parallel yarns, i.e. yarns without folding twist, increase in the number of plies has insignificant effect on warp-way, weft-way and overall stiffness of the fabric. Fabric having warp and weft of the same twist direction has higher warp-way but lower weft-way stiffness compared to a fabric having warp and weft of different twist directions, when the number of plies in. the yarn used is the same. Page(s): 48-51

Effect of Wet Processing Parameters and Type of Weave on the Shrinkage of Polyester/Viscose Blend Fabrics

2016-07-20T05:47:14Z

Title: Effect of Wet Processing Parameters and Type of Weave on the Shrinkage of Polyester/Viscose Blend Fabrics Authors: Sharma, I C; Pandey, Vijay; Thakur, Sarvesh; Ojha, S P Abstract: The dependence of fibre shrinkage on wet processing parameters, viz. dry setting temperature, pH of the bath conditions of hot water treatment and repeated wetting-drying treatments, has been studied in the case of three common polyester/viscose blend (15/85, 30/70 and 48/52) compositions adopting different weaves—plain twill hopsack and satin. Blends with higher viscose contents showed greater combined swelling and relaxation shrinkages on treatment with distilled water and alkaline solutions. On the other hand blends with higher polyester contents exhibited greater combined relaxation and swelling shrinkages on being subjected to dry heat. Weaves with longer floats and fewer interlacements showed greater shrinkage compared to other weaves. Page(s): 42-47