Tensile properties of plant fibres readily available in north-eastern region of India

Tensile properties of fibres (raw and degummed) obtained from the bark of lady' s fin ger, seeds of betel nut and Ic,lvc s of pineapple have been investigated using the Fefegraph and Vibromat-M. Tenacity, elongation , breaking load , initial modulus, work factor and work of rupture were determined from the experimental data. Tenacity and elongation ror th e raw fibres of lady's finger, betel nut and pineapple have been found to be 4.31 g/den and 3.32%, 2.16 g/den and 11. 9(X., and 5.71 g/den and 5.21 % respectively. These parameters for degummed lady's finger, betelnut and pineapple fibres arc 5 .2 g/de n and 5. 1 %, 1.5 g/den and 12.45 %, and 5.8 g/den and 8.1 % respectively. Further, it has bee n observed that th e de ni e r or the same fibre is different and that the breaking load is dependent on the fibre denier while th e elongati o n a nd tenacity a re independent. The plant fibres from the bark of lady's finger (Abelmoschus esculentus Syn. Hibiscus asculentus), seeds of betelnut (Areca catechu) and leaves of pineapple (Ananas comosus) are organic polymersl2. For processing the fibres , it is important to know their mechanical properties because fibres sometimes show some abnormal irregularities in their characteri stics which give trouble in weaving and subsequent processing operations. The quality of the final products a lso depends on the mechanical properties 3 .4 . Morton and Hearle 5 studied the physical properties of textile fibres . Pakhomov et 01.6 studied th e relationship between the mechanical properties and the conformational compositions of polymers. The effect of water on the mechanical stress relaxation of silk fibres was studied by Haziwara et 01.7. The co­ relation of the fine structural characteristics and textile properties of natural fibre was studied by Padhi et 01.8 The effect of direct and indirect drying of fibres (jute, mesta, roselle) on tenacity was studied by Ra/. The effect of chemical degumming on the linear density and surface morphology of pineapple fibres has been studied by Doraiswam/o. The mechanical properties (tensile, etc.) of th e natural si lk fibres (muga, eri and pat) of north-eastern region of India were studied by Baruah et 01. 3 But no work on the tensile properties of lady 's finger, pineapple and betel nut fibres of this region has been reported. In the present investigation, an attempt has been made to study the tensile properties of these fi bres. 2 Materials and Methods The fibres of lady's fin ger we re e xtracted from th e bark of the plant. The betel nut fibres were extrac ted from the outer portion of th e seed . These were collected from the various locati ons of Assam. The pineapple leaves were collected fro m th e foothill of Guwahati and the fibres were extracted fr om th e middle portion of the leaf. Prope r processing for th e extraction of differe nt fibres was done by th e usual process. One portion of th ese raw fi bres was treat ed with 6% NaOH using th e method desc rib ed elsewhere ll . Both raw and degummed fibres we re