Abstract
The energy method, used for the derivation of the tensile properties of continuous filament yarns by L. R. G. Treloar and G. Riding and by J. W. S. Hearle, is applied to the compound filament consisted of cocoon fiber and TETORON (PET filament).
The tensile stress as a function of strain is expressed by the following equation:
Where fy (εy): stress of the twisted compound filament at a strain of εy
ms: total denier of cocoons
mc: denier of core filament
M=ms+mc
Fs: stress of cocoon fiber that is a function of the strain εs and determind experimentally from its s-s curve.
Fc: stress of core filament which is a function of the strain εc and determined experimentally from the s-s curve.
K=∂εs/∂εy
ε_??_=(β-γ)/(1-β)
β: the twist-shrinkage of the compound filament
γ: the twist-shrinkage of TETORON
The s-s curves of cocoon fiber and TETORON and the twist-shrinkages of TETORON and the compound filament are introduced into this equation. The satisfactory agreement is found between the results calculated and observed. From this result, it may be said that the tensile behavior of the twisted compound filament is accounted satisfactorily by the above equation.
