Twist-factor

Filament yams require much lower twist factors for optimum strength than spun yams. These yams are often used as suppHed by the manufacturer and contain producer twist only, which can be as low as 0.25 turns per centimeter. 

Both washed and unwashed cottons were processed through a blender feeder, a No. 12 horizontal opener, and a two-beater picker and made into picker laps. The carding was conducted in our model cardroom at 18,2 kg/h, and dust levels were determined by use of vertical elutriators. The cottons were spun into 19.7 mg/ m yarn of 38.2 twist factor at 13000 rpm spindle speed in a 4536 spindle-hour test. 

All cottons were carded at 13,6 kg/hr. The Mississippi and California cottons were processed into both 14.8 mg/m yarn of 37.2 twist factor and 19.7 mg/m yam of 38.3 twist factor at several spindle speeds. The Texas cotton was made into 19.7 mg/m yarn of 38.3 twist factor at 12500 rpm spindle speed. 

This cotton was carded at 13.6 kg/hr and processed into 1A.8 mg/m yarn of 37.2 twist factor at 10000 rpm spindle speed. Ends down per thousand spindle hours was AO as compared to 56 for the same cotton washed on the rayon line. Yarn appearance characteristics were also slightly better for the wool scoured cotton. 

However, as shown above, filament diameter can be different if the polymer density is different, so the above equations for cover factor can in many cases be only a guide and may need to be modified for density if comparisons arc to be made. Also, of course, in the case of staple fiber yarns particularly, twist factor can have a marked effect on the yarn density and hence on yarn diameter, but as a first approximation the yarn diameter of a staple fiber yarn spun on the cotton system can be found from... 

By optimizing the spandex draw ratio and twist factor, one achieves better covering effect and elasticity (Zhang et al., 2006). 

Yarns can be continuous filament or spun from staple fiber. A measure of the diameter is obtained from the tex (g of 1 km of yarn) although the spun yarn will not be uniform in cross-section. There are two types of twist, designated S and Z as depicted in Figure 17.24. When one measures the twist, it does not take into account the diameter and to allow for this, a twist factor can be introduced where ... 

Tex twist factor Direct system, equals tums/meter x Vtex ount. 

The actual shape of the pore is different. It is not only the columniform pore, but all kinds of it may be straight or twist like a maze. The shape of the pore will affect the gas diffusion and hydrodynamics. The macroscopical nature of solid catalysts is usually characterized with twist-factor or maze-factor. For example, the average value of the tortuosity factor of A301 catalyst is 3.28. ... 

Bingchen Zhu et al used the d3mamic method and determined the twist-factor of ammonia synthesis catalyst A301 in SPSRM. The twist-factor of catalyst A301 obtained is 3.28. 

Air permeability is a quality that relates closely to wearer comfort. The authors examine various fabric parameters to develop a statistical model for air permeability. They propose a polynomial model with linear terms of cover factor, fabric thickness, twist factor, and yam packing factor, and quadratic terms of cover factor, fabric thickness, and packing factor ... 

Yarn twist P = z 10 -a m target false twist O n z Twist factor Machine efficiency (%) Number of spinning positions... 

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