Page 293 - Handbook of Properties of Textile and Technical Fibres

Tensile properties of cotton fibers: importance, research, and limitations 267

Table 7.2 Typical values of skein break factor (lb$Ne) (Elmogahzy
and Chewning, 2001)

Yarn type/Ne (s) Range Mean value (lb$Ne)
Ring-spun (carded)
Ne ¼ 20 1774e3129 2227
Ne ¼ 36 1584e3096 2045
Ring-spun (combed)
Ne ¼ 22 2886e4009 3430
Ne ¼ 36 2653e3737 3223
Ne ¼ 50 2433e3587 3042
Open-end (carded)
Ne ¼ 10 1979e2898 2347
Ne ¼ 22 1663e2669 2005
Ne ¼ 30 1507e2415 1814

Table 7.3 Typical values of tenacity, breaking elongation, and work of
rupture for ring-spun carded yarns (Elmogahzy and Chewning,
2001) (Uster Tensorapid)

Tenacity (cN/ Breaking
tex) elongation (%)
Count range (Ne) Work of rupture
(s) Mean CV% Mean CV% (cN$cm)
6e10 17 6e7 8e7.2 6e6.6 3000e1700
10e20 17 7e8.5 7.2e6.4 6.6e7.5 1700e800
20e40 17 8.5e10 6.4e5.6 7.5e8.5 800e350

7.17.2 Fiber-to-yarn strength relationships

Research efforts on the effect of the tensile behavior of cotton fibers on the correspond-
ing behavior of cotton yarns have focused on exploring fundamental relationships
between the tensile parameters. The classic work by Hearle et al. (1969) explains
the contribution of fibers that are twisted together to form a yarn using the ratio
between yarn tensile modulus and fiber tensile modulus determined from the following
expression:

Yarn strength ðor modulusÞ E y 2
¼ ¼ cos a½Lf k$cosec aŠ
Fiber strength ðor modulusÞ E f