Abstract
This paper is devoted to evaluate the general relationships in connection with mechanical properties of sliver-like fibre system with those of constituent fibers and to investigate the application of these relations to the particular case of extension of regular staple rayon slivers.
Theoretical formula of load P-extension γ curves of sliverlike system is expressed by: Here Young's modulus E0, Poisson's ratio Σ0 of sliver are dependent upon (1) sliver structures; gauge length L0, cross section A0, density _??_0, (2) fibre properties; Young's modulus εf, Poisson's ratio σ, coefficient of friction f, and (3) fibre dimensions; mean length _??_0, diameter b0, density ρ0.
Then we have:
These expressions suggest that P(γ) curve may be inverse sigmoidal, concave, sigmoidal or convex in accordance with the change of sign of constants, b and c.
The experimental results of constant-rate of loading tensile tests for the regular staple rayon sliver indicate that their load-extension curves are sigmoid, and that their Young's modulus, Poisson's ratio, breaking strength and breaking elongation are related to the sliver structures and single fibre properties, and can be predicted from them fully.
The observations also show that stick-slip movement of fibre in extension of sliver is a function of sliver length and rate of loading.
