INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY 1560–8530/2003/05–3–364–366 http://www.ijab.org Cotton and Polyester Double Rove Feeding Effect on Blend Yarn Imperfections SH. M. NAWAZ, BABAR SHAHBAZ, M. IFTIKHAR AND M. ILYAS Department of Fibre Technology, University of Agriculture, Faisalabad–38040, Pakistan ABSTRACT The effect of roving position twist factor and spindle speed upon thin and thick places and yarn neps were investigated in this study. The roving displacement of 15 mm span recorded excellent over yarn imperfections. The lowest spindle speed also generated similar effects. Factors strand spacing and spindle speed also presented highly significant interaction; whereas, twist factor and its interactions showed non-significant differences for yarn imperfections. Key Words: Double rove feeding; Cotton/polyester blend; Yarn imperfections; Spindle speed INTRODUCTION Among synthetic fibre derivatives, polyester fibre consumption is the highest not only due to its tensile parameters but also due its blending susceptibility. When polyester properly combined with cotton, it adds strength, provides smoothness, silkiness and dirt rejection. It also reduces the weight of the fabrics and increases its wrinkle resistance. Whereas, cotton gives body to the yarn softness and essential moister absorption. The combination permits the weaving of fabrics that are soft, supple, and extremely serviceable when polyester blend with cotton, it develop a cotton rich, high tenacity, filament core yarn and fabric with sufficient cotton on the outer surface for effective flame retardant and durable press finishing. Polyester blended with cotton is also reported to provide the wearer with the same protection against the flash thermal radiation. Blending is to assemble and combine together the correct proportions of component fibres so that the relative amount of each fibre should be present in it. Blending process is not an intimate mixture of fibres but rather a fibre assembly in the required proportions to enable the following process to bring about the necessary fibre to fibre mixing. Double rove spinning is becoming more popular because of tremendous cost saving. Double rove feed is a process of feeding two rovings side by side in the drafting zone and combined at the nip of the front roller. This technique provides a yarn with improved strength of 14% pure cotton than the conventional yarn and less hairiness. A novel pseudo composite blend yarn of improved strength can be produced by separating, the drafting of different component rovings on a modified ring spinning frame. A cotton/polyester composite blend yarn thus produced gives about 14% higher strength than a similar blend yarn produced with the same rovings combined and drafted together in the spinning drafting zone. A 65/35 or a 50/50 cotton/polyester blend yarn made with the new technique may be significantly stronger than the comparable conventional yarns. These cotton-rich yarns, being relatively stronger, should make stronger fabrics. This yarn, being stronger, may also yield substantial productivity gains in the down stream yarn preparatory and weaving processes and provide improved product quality and performance. Because of the potential gains in the productivity and quality, these new relatively strong yarns and fabrics may even offer some overall cost advantages over the conventional products, as there should be no difference in the manufacturing costs of these types of yarn. Moreover, twist in thin places increases the bulk density. If further twists are added it flows into thick places causing a reduction in the difference between the visual appearance of thick and thin places. Therefore proper amount of protective twist must be inserted in order to hold the fibre together. The spacing between cotton and polyester rovings drafting simultaneously on the ring frame affects yarn structure, resulting in significantly stronger yarn, than those produced by drafting the same two rovings together. The composite or combination yarns may be useful in developing relatively stronger cotton rich materials suitable for variety of finishes and end uses. Bandopadhay et al. (1982) reported that blend proportion and count of yarn had a major effect on yarn quality; whereas, Mumtaz (2001) recorded the range value of 30s PC yarn for evenness as 10.37-10.61%. Ahmad (1994) also observed highly significant effect of twist upon yarn regularity. Stalder (1991) concluded that increasing tension leads to the poorest IPI values. MATERIALS AND METHODS The present technological study on the “multi roving blending of cotton and polyester at ring frame” was initiated in the Department of Fibre Technology, University of Agriculture, Faisalabad and carried out at the Crescent Textile Mills Limited, Faisalabad during the year 2001. The details of raw materials spun and the methods applied to determine the various quality characters of raw cotton, polyester fibre and its spun yarn are described here under. Materials. The representative lint cotton samples of the variety MNH-93 and polyester fibre were collected from the