ABSTRACT
Current HVI bundle testing machines follow the custom of comparing bundle tensile tenacity with yarn tensile tenacity as a means of predicting how a particular cotton should behave during spinning as established from past testing with Pressley and Stelometer testing machines: simple correlation analysis. The HVI bundle testers, however, use different methods to evaluate bundle mass (hence, bundle tenacity), have tapered fiber bundles (thus, all fibers are not broken  a reason to suspect bundle tenacity), and use different clamping techniques than the other, older methods cited. The purpose of this work is to establish how stelometer data measured at each of four different gauge lengths and compared with five different fiber properties are related to yarn data for 43 different cottons. Such analyses will help to determine how testing methods used by the two different HVI machines should be altered to conform with each other and Stelometer data. Two equally good methods of evaluating yarn data have been found: (1) Multiple correlations of yarn twist factor and fiber properties: of fifty percent xray angle, maturity, linear density, and mean length are sufficient to evaluate yarn secant modulus for 39.4 and 19.7 tex yarns. (2)When bundle secant modulus is considered, multiple correlations of bundle secant modulus at any gauge length, yarn twist factor, and fiber properties: maturity and linear density are sufficient to evaluate yarn secant modulus for 39.4 and 19.7 tex yarns.
