The Measurement of the Axial Tearing Force to Derive the Transverse Mechanical Properties of Acrylic Fibres

Abstract

A technique for measuring a lateral-cohesion value of single fibres is developed and applied to wet-spun textile acrylic fibre. Although the measurements on high-performance fibres by means of this technique were successful, the lower level of mechanical anisotropy of textile acrylic fibre reduces the effectiveness of measurement. Uniaxially drawn films were adopted as fibre analogues to facilitate sample manipulation. By using films, it is shown that a lower as-formed network density imparts a lower level of transverse cohesion in drawn material, whereas a higher level of transverse cohesion results from a lower level of process drawing. However, the level of orientation induced by stretching is shown to be sensitive to network density, with greater efficiency of orientation resulting from the drawing of fibres with a higher as-formed network density. Consequently, in comparing the lateral strengths of samples produced with different network densities, account should be taken of the effective orientation rather than the draw ratio applied.