Yarn Formation

Fig. 12.28. Flow diagram for manufacture of textile glass fiber (1) glass batch (2) batch cans (3) marble forming (4) cullet cans (5) marbles (6) melting furnaces (7) filament yarn formation (8) gathering and sizing (9) yarn packaging (10) air jets (11) lubricant spray (12) collection for staple fibers (13) staple fiber packaging. (Courtesy Owens-Coming Fiberglass Corp.)...

Yarn Evidence. Several types of yarn formations were distinguished. The paired-fiber yarn shape evident in the yam-type formations is present in the fabric-type areas as well (Figure 5). For the most part, this formation is green in color, indicating malachite however, some of the paired fiber yarn shapes are a dark brown-black in color. These darker entities appear more often in the fabric-type zones than in the yarn-type areas. 

Not surprisingly, paired-fiber yarn formations of both colors ranged from 80 xm, a dark yarn with 0 twist, to 107.8 xm for another dark yarn with S-twist, designated ( ). All the green, paired-fiber yarn formations measured approximately 100 (Jim in size. 

A three-ply yarn shape was identified and measured (Figure 8). It was dark brown-black in color and was composed of three paired-fiber yarn formations ( ) that were plied together in (/) direction. The ply yarn was calculated to be 127.45 (xm in size one of the paired-fiber yarn pseudomorphs, to be 107.8 xm and a single fiber, 58.8-68 (xm. No green yarns were observed larger than 100 xm. 

Implications of these findings will be examined in later work. Suffice it to say here that a variety of yarns were observed, and all were related to single and paired-fiber yarns and were eitiier green or black. The evidence of yarn formations is summarized in Table II. 

Two types of nonrectilinear yarn formation were identified, a curvilinear yarn movement and a linear one that moved in a zig-zag, 45° angle relative to the fabric structure (Figures 6, 9). That these were identified along the surfaces of the formations suggests a surface decoration. However, until further study confirms this point, the function of system C yam formations within the fabric pseudomorphs remains uncertain. 

Smit et al [30] developed a method which uses an open hquid (water for instance) surface to collect nanofibers. The wet nanofibers are then pulled out of the liquid bath with a rotating drum. Fiber orientation is formed when the nanofibrous mat leaves the bath resulting in a continuous yarn. The scheme of the process can be seen in Figure 10.22 and the yarn formation mechanism from top view can be seen in Figure 10.23. 

In the process of yarn formation on conventional ring-spinning machines, individual fibres emerging from the nip of the front rollers change their radial position (migrate) until it is fixed by friction between the fibres generated... 

Self-assembled yarn formation. Reprinted with permission from reference 19 with kind permission from the author. 

The process of yarn formation is illustrated in Fig. 3.11. It can be described in three phases. In the first phase, a flat web of randomly looped fibers forms... 

Top view of the yarn formation process. Reprinted from reference 38. Copyright (2005), with permission from Elsevier. 

With only a few exceptions, most of the open literature on yarns from electrospun fibers focuses on the process of yarn formation, mih i than on the yarns obtained. Although the process is certainly an mq)ortant aspect, researchers should bear in mind that ultimately the intended end-user of their results will be the fibers and textiles manufacturing indushy. With this in mind, future research should pay more attention to the properties of the yarns obtained, and report more on these with specific focus on tenacity, elasticity and linear density values. 

For more information on yarn terminology and definitions of textiles terms, the reader is referred to the Textiles Intelligence glossary of textiles terms (http //www.textilesintelligence.com/glo/). For more information on specific yarn formation processes discussed in the previous sections, the reader is referred to the specific publications or patents as cited. 

The first functioning rotor spinning machine was presented at ITMA 1967. Yarn formation according to the rotor spinning principie predominates for aii noncon-ventionai spinning methods. Woridwide, more than 8 million spindles are in operation (Schindler, 2013). 

Figure 3.22 Yarn formation process (Courtesy of Murata)...

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