Published research has indicated that cotton strength increases as the specimen loading rate increases when measured by Stelometer and Pressley methods. This report describes an instrument designed to test 1/8 gauge bundles at constant rates of extension from 0.05 to 50 cm/min. A computer analyzes voltage signals from force and dis placement transducers. Pressley jaws hold the fiber bundles, and a Stelometer vice is used to load them in the jaws. Specimens are selected with a mechanized sampling and combing procedure. The method provides measurements of strength, elongation, modulus, and two forms of toughness.
References
1.
American Society of Testing Materials, Committee D-13 on Textile Materials, ASTM Designations D-123 and D-1445-75, 1982.
2.
Brown, R.S., Godbey, L.C., and Taylor, R.A., Factors that Affect the HVI Bundle Force Measurement, in " Proc. 13th Beltwide Cotton Production Research Conference,"National Cotton Council, Memphis, TN, 1989.
3.
Hertel, K.L. , and Craven, C.J., CottonFiber Bundle Elongation and Tenacity as Related to Some Fiber and Yam Properties , Textile Res. J.26, 479-484 (1956).
4.
Lawson, R., Strength of Cotton Fibers as Measured by the Pressley Tester and the Stelometer , Textile Res. J.34, 725-731 (1964).
5.
Phillips, J.K. , Laboratory Techniques: A Comparison of Fiber Tensile Values Obtained on the Pressley Tester and Scott IP-4 at Different Test Speeds , Textile Res. J.19, 274-277 (1949).
6.
Taylor, R.A. , Measurement of Cotton Fiber Tenacity on 1/8 Gauge HVI Tapered Bundles, ASME Trans. J. Eng. Ind.104, 169-174 ( 1982).
7.
Taylor, R.A. , CottonTenacity Measurements with High Speed Instruments, Textile Res. J.56, 86-94 (1986).
8.
U.S. Dept. of Agriculture, Summary of Cotton Fiber and Processing Test Results, Crop of 1986, Agriculture Marketing Services, Cotton Division, Clemson, SC, 1987.
