On two sets of selected cotton samples the effect of the fiber length distribution (represented in this report by the AFIS short fiber content by weight) and the AFIS standard fineness on yarn strength and yarn uniformity was investigated. It is intuitively simple to understand that the fiber length distribution will have an effect on yarn geometry and, therefore, on yarn regularity. But it is not intuitively obvious why "standard fineness" would be a better predictor of yarn quality than "fineness."

On these sets of samples, the AFIS standard fineness is highly and negatively correlated with both CSP and yarn tenacity. The AFIS short fiber content by weight is higly correlated with yarn non-uniformity, the number of thin places and thick places on the Saco Lowell ring spinning frame. After short fibers are removed by combing, yarn non-uniformity, the number of thin places and thick places are highly correlated with AFIS standard fineness.