Textile fabrics cover a vast range of consumer and industrial products made from natural and synthetic fibers. Figure 1.2 illustrates that, to produce a fabric for a particular end use, the fiber type has first to be chosen and then spun into a yarn
structure of specified properties so that the subsequent woven or knitted structure give the desired fabric aesthetics and/or technical performance.
Textile fabrics are also made by means other than knitting and weaving, which may just involve bonding fibers or filaments together without the need of converting them into yarns. Although such nonwoven fabrics are an important area of textile manufacturing, especially for technical and industrial end uses, they have limited application in the consumer sector. It is reasonable, then, to say that, second only to fibers from which yarns are made, yarns are the basic building blocks of most textile fabrics. Many required fabric properties will, in addition to the fiber properties and the fabric structure, depend on the structure and properties of the constituent yarns. Therefore, in the study of yarn manufacture, we need to determine not only how yarns are made but also how to get the required properties for particular end uses. To achieve these two goals, we must first establish the factors that characterize a yarn.
A SIMPLE ANALYSIS OF YARN STRUCTURE
we will consider in detail the various yarn structures. Here, a simple analysis is given so as to answer our question, “What is a staple-spun yarn?”
The following three characteristics are evident:
1. A linear assembly of fibers. The assembly could be of any thickness
2. The fibers are held together by twist. However, other means may be used to achieve cohesion
3. There is a tendency for fibers to lie in parallel along the twist spiral. From these three characteristics, we can now answer the question,
“What is a staplespun yarn?” with the following definition: A staple-spun yarn is a linear assembly of fibers, held together, usually by the insertion of twist, to form a continuous strand, small in cross section but of any specified length; it is used for interlacing in processes such as knitting, weaving, and sewing. The reader should note that there are several other definitions,3,4 but these are more general, covering filament as well as staple-spun yarns.
