NOPR Collection:

Lambda-cyhalothrin spray as an insectproofing agent for woollen fabrics

2016-07-20T05:55:10Z

Title: Lambda-cyhalothrin spray as an insectproofing agent for woollen fabrics Authors: Veer, Vijay; Gopalan, N; Rao, K M Abstract: The effectiveness of synthetic pyrethroid lambda-cyhalothrin at 0.01, 0.025 and 0.05% concentrations as solvent-based sprays was evaluated against the larvae of the tropical case making clothes moth,Tinea translucens Meyrick and the furniture carpet beetle, Anthrenus falvipes LeConte. Lambda-cyhalothrin spray at 0.025 % concentration provided high degree of protection to the wool fabric even after 30 months of the ageing of treated fabric from these two serious wool pests.Lambda-cyhalothrin showed ovicidal action as all eggs, laid on the treated fabric by the moths, were killed. The minimum effective concentration of lambda-cyhalothrin for complete protection of woollen fabric was determined to be 0.005% on wool weight against the larvae of A. flavipes. T. translucens was found more susceptible than A. flavipes to lambda-cyhalothrin. Residue of lambda-cyhalothrin was estimated 25-35% lower than its initial deposits on the fabrics after 30months of its application. Page(s): 308-312

Studies on physical properties of jute-acrylic blended bulked yarn

2016-07-20T05:54:04Z

Title: Studies on physical properties of jute-acrylic blended bulked yarn Authors: Sinha, A K; Basu, G Abstract: Jute-shrinkable acrylic blended bulked yams of various blend ratios have been prepared by relaxing shrinkable componentof the yams using three different methods of thermal treatments, namely dry hot air, steam and boiling water. The performance of these methods of bulking has been compared. It is observed that all the three methods produce bulked yarn shaving more or less same value of specific volume. Since the boiling water method is easier, convenient and economical,this method is adopted for detail study. The optimum treatment time in boiling water is found to be 30 min. Flexural rigidity of yarns decreases remarkably after bulking and shows a decreasing trend with the increase in percentage of acrylic up to80%. Breaking strength and breaking extension of non-bulked yam increase with the increase in percentage of acrylic. The extensibility further increases remarkably after bulking but the breaking stress of parent yam decreases remarkably on bulking. The loss of tenacity is more when percentage of jute is more in the blends. Page(s): 268-272

Fibre-reinforced composites: Their fabrication, properties and applications

2013-12-18T16:45:35Z

Title: Fibre-reinforced composites: Their fabrication, properties and applications Authors: Gupta, VB Abstract: An attempt has been made to describe the wide range of composites based on the combination of reinforcing fibres likecarbon, aramids, high-modulus polyethylene, ceramic, boron and glass with matrices like thermosetting resins, thermoplasticpolymers, soft metals, ceramics and carbon. Starting with the definition and classification of composites, the advantagesof the fibrous shape and of an optimum adhesion between the fibre and the matrix are considered. This is followed byan account of the properties of the constituents of the composites, viz. the fibres and the matrices. The composite fabricationprocesses are then described. Finally, the properties and major applications of the composites are briefly discussed. Page(s): 327-340

Studies on the properties of alkali-treated jute-modacrylic flyer-spun yarns

2016-07-20T05:32:49Z

Title: Studies on the properties of alkali-treated jute-modacrylic flyer-spun yarns Authors: Chaudhuri, Atin; Basu, Gautam Abstract: Jute and jute-modacrylic yams of various blend ratios have been prepared and treated with different concentrations of NaOH (5% -22% w/w). It is observed that this treatment results in axial shrinkage and weight loss of the yarns. The axial shrinkage increases with the increase in NaOH concentration up to 1 8% whereas the weight loss increases with the increase in NaOH cone. up to 22%. Even though the tenacity and modulus of yams decrease substantially on alkali treatment, the work of rupture increases after treatment which is mainly due to the increase in breaking elongation. Statistical analysis shows that the modulus of different strain levels and tenacity values are positively and significantly correlated with the packing fraction values of the yarns. Blending of modacrylic fibre with jute does not show any appreciable improvement in bulk property of yarn. However, the whiteness index and mean gray value of alkali-treated blended yams confirm the improvement in appearance of the yams due to the preferential migration of modacrylic fibres on the surface of the yarn. Page(s): 239-245