NOPR Collection:

Effect of Drafting on the Characteristics of Woollen Yarn

Tue, 01 Jun 1982 00:00:00 GMT

Title: Effect of Drafting on the Characteristics of Woollen Yarn Authors: Patni, P C; Pokharna, A K Abstract: The effect of drafting on the characteristics of woollen yarn, such as strength, elongation and CV% has been studied. It is observed that maxima of yarn breaking load and tenacity are obtained at drafts of 1.1-1.25 and 1.1-1.5 respectively. The yarn breaking elongation reduces irregularly with increase in draft. Page(s): 61-62

Length Distribution of Jute Fibres at Different Preparing Stages and in Yarns

Tue, 01 Jun 1982 00:00:00 GMT

Title: Length Distribution of Jute Fibres at Different Preparing Stages and in Yarns Authors: Banerjee, B L Abstract: The length distributions of fibres in jute slivers at different preparing stages and in yarns have been studied using the samples of hessian warp and weft quality products collected from different manufacturing mills. The nature of change in the distribution pattern of length brought about by the processing operations has been examined both separately and in combination for the two broad categories of fibres, namely unfolded (i.e., linearly oriented) and folded (i.e. disoriented). The proportion of folded fibres and the average value and length range of both the folded and unfolded fibres decrease from finisher carding to spinning, while the length CV of the unfolded fibres appears to have a rising trend at second drawing followed by a relatively sharp fall at finisher drawing and spinning. The drafting process seems to cause rupturing of the longer fibres of both the categories in addition to straightening of the folded ones. Page(s): 56-60

Thermal Degradation of Cellulose and Its Esters in Air

Tue, 01 Jun 1982 00:00:00 GMT

Title: Thermal Degradation of Cellulose and Its Esters in Air Authors: Jain, Rajesh K; Lal, Krishan; Bhatnagar, Hari L Abstract: The thermal degradation of cellulose and its esters (β-chloropropionate, acetate) in air has been studied by dynamic thermogravimetry and differential thermal analysis from ambient temperature to 600^oC. The values of the energy of activation of thermal degradation, E_a, for cellulose and its esters lie in the range 155-225 kJ mol^-1. However, the values of free energy of activation for the degradation of cellulose and its esters are almost same and lie in the range 152-185 kJ mol^-1. This indicates that the basic step in the thermal degradation of cellulose and its derivatives is the same. IR spectra of the pyrolysis residues of cellulose β-chloropropionate gave indication of dehydration and formation of a compound having C = 0 groups. Page(s): 49-55

Application of External Reflection Spectroscopy to a Study of Chars Formed during Fabric Combustion

Tue, 01 Jun 1982 00:00:00 GMT

Title: Application of External Reflection Spectroscopy to a Study of Chars Formed during Fabric Combustion Authors: Kulshreshtha, A K; Pandya, H B; Bhagwat, M M Abstract: External reflection spectroscopy has been applied to investigate the initial stages of cellulose degradation occurring during the combustion of textiles. The technique offers a convenient means of characterizing the char residues formed upon the ignition of flame-retardant textiles. It also enables exploration of the chemical changes in a fabric occurring at temperatures below or on the threshold of charring, leading to darkening and loss in fabric strength. Page(s): 45-48