Textile Sizing
2 PROPERTIES OF FIBERS AND YARNS 2.1 INTRODUCTION The utilization and serviceability of textile materials, other than industrial or technical textiles, are determined by their physical and mechanical properties, which include softness, pliability, good handle, feel, and drape [1]. The pliabil- ity of a textile structure is attributed to the fact that it is composed of a number of individual elements, commonly referred to as yarns. These yarns are made up of either staple or filament fibers, having sufficient degree of freedom of movement within the fabric structure without causing distortions. The softness and pliability of textile fabrics are due to this freedom of movement of constitu- tional elements, i.e., the fibers and yarns. The yarns are generally formed by twisting a bundle of fibers together. Though the process of twisting generates transverse pressures to prevent slippage of fibers, especially in staple yarns under axial tension, the yarns still retain flexibility because of the inherent flexibility of textile fibers. Obviously, it implies that the properties of textile structures will depend substantially upon the properties of fibers, which are the true building units. The process of woven fabric manufacturing is neither simple nor accom- plished in one step. The conversion of raw materials (fibers) into finished products (fabrics) involves many different steps, broadly categorized as spin- ning of a yarn, weaving of a fabric, and finishing. Each of these steps in turn involves many intermediate processes to perform well-defined specific functions. The process of spinning staple yarns involves preparatory steps such Copyright © 2004 Marcel Dekker, Inc. Properties of Fibers and Yarns 19 as opening and cleaning of cotton fiber stock, or only opening for synthetic fibers, optimal blending of different fibers, carding, combing, drawing, and twist insertion.
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