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Measures for Judging Combing Performance

Fri, 01 Dec 1978 00:00:00 GMT

Title: Measures for Judging Combing Performance Authors: Srikantaiah, G. Abstract: The digital fibrograph has been used to access the extent of Improvement in fibre length characteristics resulting due to combing Norms for combing performance have been derived on the basis of tests contented on a large number of cotton samples. These norms are found to be helpful in identifying combers giving poor performance. The use of these norms in reducing comber waste without in any way affecting the yarn quality is also considered. Page(s): 129-132

Preparation of Chlorendic Acid Based Polyester Resins

Fri, 01 Dec 1978 00:00:00 GMT

Title: Preparation of Chlorendic Acid Based Polyester Resins Authors: Gupta, S. K.; Krishnan, M.; Thampy, R. T. Abstract: Four polyesters were prepared by stepwise condensation of isophthalic acid, chlorendic acid and maleic anhydride with propylene glycol using p-toluenesulphonic acid as catalyst and xylene as entrainer. The quantities of maleic anhydride and propylene glycol used were 1 and 2.2 moles respectively and the molar ratios of chlorendic acid to isophthalic acid were 0.2, 0.8, 0.4, 0.6, 0.6, 0.4 and 0.8, 0.2 for the four polyesters prepared. The polyesters obtained bad better colour and relatively more uniform distribution of chlorendic acid over the polymer chain compared to the polyester made in one step. They were crosslinked using 30% by weight of styrene and were characterized through the determination of viscosity, gel time, peak exotherm and acid value. They were evaluated by measuring vicat softening point, heat distortion temperature, rate of flammability and rate of hydrolysis. The data reveal that the polyester obtained using chlorendic acid and isophthalic acid in molar ratio 0.6, 0.4 is the best among the four polyesters prepared. Page(s): 124-128

Studies on the Development of Glass-Reinforced Polypropylene: Effect of Silane Coupling Agents on the Properties of the Composite

Fri, 01 Dec 1978 00:00:00 GMT

Title: Studies on the Development of Glass-Reinforced Polypropylene: Effect of Silane Coupling Agents on the Properties of the Composite Authors: Gupta, V. B.; Pandit, S. N.; Singh, R. K.; Subramaniam, K.; Bajaj, P. Abstract: The development of glass-reinforced polypropylene involves optimization of tile processing parameters, the glass fibre content and the adhesion between the glass fibre and the polypropylene matrix. Substantial enhancement in some properties like tensile strength tensile modulus heat distortion temperature in glass fibre-reinforced polypropylene was achieved on adding some silane coupling agents. However, there was considerable reduction in elongation-to-break. The adhesion of the glass fibre with the thermoplastic matrix is shown to be an important factor in determining the improvement in strength. The coupling agents used in polymeric form gave better results compared to those used in monomeric form. Page(s): 119-123

Physical and Mechanical Characteristics of Wools of Some Cross-Bred Sheep

Fri, 01 Dec 1978 00:00:00 GMT

Title: Physical and Mechanical Characteristics of Wools of Some Cross-Bred Sheep Authors: Arora, R. K.; Patni, P. C.; Gupta, N. P.; Pokharna, A. K. Abstract: Improvement in the quality of wool of two native breeds of sheep (Chokla and Nali) by cross-breeding with two exotic breeds (Merino and Rambouillet) has been attempted. While improvement in wool quality was achieved in respect of fibre fineness, percentage modulation and crimp/cm, there was deterioration in fibre tenacity and elongation. The cross-bred fibres are suitable for the preparation of medium fine apparels. Page(s): 116-118