Knitting Processes

Knitted fabrics are produced from one set of yams by looping and interlocking processes to form a planar stmcture. The pores in knitted fabrics are usually not uniform in size and shape, and again depend largely on yam dimensions and on the numerous variables of the knitting process. Knitted fabrics are normally quite deformable, and again physical properties are strongly dependent on the test direction. 

Double covered yam is wrapped by two yams in opposite directions. One is an S twist and the other is a Z twist (outer cover and inner cover). It is better for weaving and knitting processing than is SCY the different number of twists will eld a varied sense of touch. 

Metap weave-knit process n. A technique combining weaving and knitting in one operation with two independent yarn systems wound on warp beams. In the fabrics produced, woven strips are linked together with wales of stitches. Generally the fabrics have 75-85% woven and 25-15% knitted structure. 

Knitted fabrics are categorized as either weft or warp . Weft fabric is faster and more economical to produce and the process can be accomplished with a single yarn package. The warp knitting process, on the other hand, requires a warp beam, that is, a running sheet of yarns, similarly to weaving. Loops are formed transversely in the weft process and essentially vertically in the warp process (Fig. 1.14). Simplest or plain weft knits tend... 

The Cetex Institut fur Textil- und Verarbeitungsmaschinen gemeinniitzige GmbH based in Chemnitz, Germany, has been developing new areas of application for the 3D contour warp knitting process oti double-bar Raschel machines since 1997. The objective, to enable the incorporation of directly oriented thread systems into the base fabric (filler thread, weft thread), was reached (Anmi., 1997b). 

The following advantages of the knitting process have to be mentioned (Hai Dang et al., 2004) ... 

The mechanical properties of a conductive material play an important role when selection is performed for any particular textile application. Metallic filaments usually compromise good electroconductive characteristics with poorer mechanical properties. A very high stiffness and lower stretchability of metallic fibers not only makes the woven or knitting process difficult but also reduces their service life. On the other hand, polymeric fibers or yams exhibit good elongation and recovery properties. The combination of nonstretchable metallic fibers with stretchable polymeric yams creates a new class of metal-based electroconductive fibers, which is known as co-spun polymeric-metal yams (Fig. 28.3). 

However, in clothing industry, the use of carbon fibers is limited because of their stiffness and brittleness, which makes especially knitting processing difficult. Weaving is more easily performed. Not only this, their esthetic considerations and health-related issues are also strong reasons for restricted use in apparel applications. 

The use of the knitting process enabled the knitted loops and stitches to be cross-linked in order to reduce resistance for heating elements made from FabRoc yam. 

This makes the manufacture of heated textiles more cost effective and reduces the waste of yam. As stated earlier, FabRoc yam is elastic by nature, which challenges knitting process, as FabRoc yams tend to stretch during knitting and could break due... 

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