Effects of Fabric Pattern on the Mechanical Properties of Cotton Fabric/Unsaturated Polyester Composites

Abstract

Aims: To study the effects of fabric patterns on the properties of cotton fabric/unsaturated polyester composites made from coarse plied yarns. Place and Duration of Study: Department of Textile Science and Technology, Ahmadu Bello University, Zaria, Nigeria, between January to December, 2014. Methodology: Four different coarse yarns of known count were plied to obtain a single strand which was woven (plain and twill) and knitted into fabrics of different patterns. The fabrics were coated with unsaturated polyester resin as matrix, applying both single and two layers of fabrics to form laminate configurations using hand layup. The tensile properties of the fabrics, tensile properties, flexural properties, impact strength and hardness of the textile composites were studied. Results: The plying and fabrication conferred significant reinforcement on the composites for the different mechanical properties tested. The tensile strengths of the plain, twill and knitted fabrics were 13.67MPa, 13.14MPa and 4.55MPa respectively. The knitted fabric recorded the highest breaking elongation of 82.1%. The tensile and flexural strengths of the composites were improved by 75-81% with respect to the neat polyester resin. Composites with twill fabrics gave the best tensile and flexural strengths of 18.5MPa and 62.32MPa with flexural modulus of 4.43GPa, closely followed by plain (3.35GPa) and knitted (3.23GPa) fabric composites. The impact test showed that the knitted composites absorbed more energy than the twill and plain fabric composites in that order. Increase in fabric layers also led to increases in the mechanical properties tested, but the increases were not geometrical. SEM images showed that the morphologies of the fractured surfaces were in line with the yarn orientations in the fabric cross-section with reduced fiber pull out. Conclusion: It’s concluded that cotton fabrics made from coarse plied yarns can be used as reinforcements in textile composites.