Influence of Yarn Hairiness on the Mechanical Properties of Unidirectional Jute Polyester Composites

Abstract

Tossa jute yarn as received from the supplier is denoted as “hairy yarn” and after removing hairs, yarn is denoted as “hairless yarn”. Hairs are removed manually by burning using a candle flame. Tensile properties of hairy and hairless yarn are measured. Differential scanning calorimetry, X-ray photoelectron spectroscopy and fourier transform infrared analysis are performed to understand the difference in properties between hairy and hairless yarns. Unidirectional (UD) mat of “unsized yarn” is prepared by wrapping it on a metal frame and UD mat of “sized yarn” is prepared by wrapping it on a drum and applying hydroxyethyl cellulose solution (a water based adhesive) as binder. Unidirectional composites are manufactured using hairy and hairless yarns separately. Unsaturated polyester resin is used as matrix and composites are manufactured via resin transfer moulding. Composites test results show an increase in tensile modulus (5.5%) and decrease in strain at failure (7.5%) of composites manufactured with unsized hairy yarn compared to those manufactured with unsized hairless yarn in the longitudinal direction. Composites manufactured with unsized hairy yarn shows an increase in strain at failure (86%) compared to that of composites manufactured with unsized hairless yarn in transverse direction.