Abstract
When a spun yarn is broken, we see generally at the breaking section some fibcrs break off and the others slip off.
We have introduced equations representing the functional relation among fliber-length, fiber-thickness, fiber-strength, friction coefficient of fiber and yarn-twist, and deterrmined the condition of the breaking-off or the slipping-off of the fibers.
We have found in conclusion, in relation to the fiber-length (λ) and yarn-twist (μ) which are the most important factors for spinning, that the strength of yarn is not influenced so far as the value of λμ2 is constant.
