Crepe Yarns-Their Diameters and Structures

抄録

Chapter 1 deals with the diameters of twisted filament yarns. Chapter 2 discusses the structures of twisted filament yarn.
In chapter 1 the authors conclude that:
Given the number n of twist turns per meter, yarn shrinkage ε_y and yarn count D denier, diamete R of twisted viscose yarn can be expressed by the following equation:
R=R₀/K√1-ε_y
where R₀ is an assumed diameter when the yarn is assumed to be filled with fibers. and is a constant value for a given yarn. K is expressed as follows:
K=0.693+0.00122D+0.000055n-(n/150)^-2.25ε_y
This empirical formula is applicable in calculating the diameters of viscose and bemberg twisted yarns.
In chapter 2 the authors reach the following conclusions:
The structure of a twisted filament yarn deviates from an ideal helical form. The deviation may be explained thus: (1) As the filaments increase in number, so the deviation becomes greater; (2) the finer the yarn count, the less the deviation; (3) the greater the yarn tension during twisting, the smaller the deviation; (4) the smaller the coefficient of friction between filaments, the greater the deviation; (5) the shape of the cross section of a filament apparently has a bearing on the degree of deviation; (6) the higher the yarn contraction rate, the greater the deviation.