Staple 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.)...

As a form of direct fabric evidence, the physical shapes of textile fabric pseudomorphs have been studied to identify fiber type and yam and fabric construction. Pseudomorphs of paired filaments in mineralized fabric formations found on Shang-period bronze weapons were determined to be replaced silk (I, 2) S-and Z-twisted silk staple yarn pseudomorphs were identified as well as fabric constructions, including float yams and a ribbed weave. 

Polyester. The most common polyester in use is derived from the homopolymer poly (ethylene terephthalate). Many types of this fiber contain a delustrant, usually titanium dioxide. Optically brightened polymers are quite common. The optical brightener, such as specially stabilized derivatives of either stilbenes or phenylcoumarins, can be added to the polyester before formation of the fiber (107). Some commercial fibers contain minor amounts of copolymerized modifier to confer such properties as basic dyeability. A wide range of polyester fibers is used for consumer end-uses. Both staple fiber and filament yarn are available. Filament yarns with noncircular cross-sections are made (107). 

Yam from staple fiben the formation of a yarn by a combination of drawing or drafting and twisting prepared strands of fibers, such as rovings. 

Fiber Length to Width Ratio Fibrous materials must have sufficient length so that they can be made into twisted yarns. In addition, the width of the fiber (the diameter of the cross section) must be much less than the overall length of the fiber, and usually the fiber diameter should be 1/100 of the length of the fiber. The fiber may be "infinitely" long, as found with continuous filament fibers, or as short as 0.5 inches (1.3 em), as found in staple fibers. Most natural fibers are staple fibers, whereas man-made fibers come in either staple or filament form depending on processing prior to yam formation. 

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