An Investigation of Mechanical Strength of Yarn or Cord Twisted with Other Kinds of Filaments

Abstract

The object of this study is to discover the most effective law of blending and the maximum limitation on the mechanical strength of a blended yarn or cord composed of two kinds of continuous filaments.
In the case of tensile rupture, the fibers making up a blended yarn resist the rupture most effectively if the mixing rate of the fibers of low extensibility is under 25% and the twist on the blended yarns is more than half the permissible maximum twist.
In the case of flexing fatigue, an ideal blended cord is obtainable if the parameter of S-N diagrams and the mechanical model of the constituent fibers of the blended cord satisfy equation (27).
The tensile strength or fatigue life of even the most effective blended yarn or cord is less than that of the mathematical mean of the constituent fibers. The amount of work (the degree of toughness) needed for the tensile rupture of the yarn or cord exceeds the mathematical mean of the constituent fibers.