Abstract:
The chapter introduces the basic definition and information on types of yarns and their classifications. It also provides information concerning the types of bobbins used for stapled and/or filament yarns. The processes of winding yarns and some of their modifications are described, and a classification of the knitting yarns is presented. The reader can find a brief description and photograph of common defects occurring during the knitting process, their names and methods of eliminating them. The chapter also describes progress in synthetic yarn production depending on design process, with some examples.
1.1 Introduction
Today, textile products are expected to comply with an increasing number of requirements. The most important of these are how comfortable the product is to use, the look of the product and its hygiene features. In order to fulfill these requirements, the ready textile product has to be eye-catching. It must possess an interesting color and design, and also be pleasant to handle, giving a sensation of smoothness, softness and elasticity. The product must provide heat insulation, but still remain permeable to air and moisture. It is also important that it maintains its shape and color stability, even after regular washing.
It is possible to fulfill these requirements by selecting the proper raw material and structure for the knitted fabric, and applying a suitable finishing process. The proper selection of the raw material seems to be the most important factor. Yarns vary greatly in terms of their physical and mechanical properties (in other words, the properties that dictate the future usage and features of the fabrics).
In recent years, researchers have combined improvements in the properties of natural and chemical fibers. Thus, the chemical fibers in a manufactured product can possess the same properties as a natural fiber. Many researchers are also concerned with the task of developing new fiber assortments, as well as improving the existing ones.
1.1.1 Types and definition of knitting yarns
In view of the general property profile, there are specific kinds of yarns for weaving, knitting and other special purposes. The properties of knitting yarns are determined by the specific requirements of both knitted goods and the knitting process itself. There are several different kinds of yarns recognized, defined on the basis of their final product application and the kind of knitting machine on which the knitting process is run. These include: tricots, hosiery, yarn for brushing, wadding yarn, yarn for elastic goods, and for other special fabrics.
Additionally, as in the classification of other yarns, there are recognized types such as single, double or multi-throw yarns. Classifications that depend on the processing of the yarn include:
ā¢ conventional yarn, traditional (staple, filament and cord);
ā¢ modified, textured.
The spinning system is used in the production of the following conventional staple yarns:
ā¢ comb yarn
ā¢ card yarn
ā¢ waste yarn
and also in the production of the following textured yarns: elastic yarn and fluffy yarn, where the elastic yarn is characterized by a very good resiliency, and fluffy yarn by bulk. A staple yarn can be made using a cotton spinning system or a wool spinning system.
We can also classify staple yarns on the basis of their raw material composition, for example:
ā¢ 100% natural fibers (e.g. cotton, wool, linen, silk);
ā¢ natural fibers blended with chemical or synthetic yarns.
The knitting yarns in the groups mentioned above are recognized as single and twisted. Filament yarn can be classified as:
ā¢ non-textured
ā¢ textured
ā¢ high elastic
ā¢ bulk.
In contrast with all th...