Technology for rapidly determining cotton fiber length distributions using single fiber measurements has been developed jointly by USDA-ARS and Schaffner Tech nologies (now Zellweger Uster, Inc.). The instrument (AFIS) includes a mechanism for mechanically opening a hand-fed ribbon of fibers so that individual fibers can be presented aerodynamically to an electro-optical system for measuring fiber length. Length measurements for 10,000 individual fibers can be obtained in approximately 5 minutes. Although there are measurements for the entire fiber length distribution, measurements of mean length, upper half mean length, and short fiber content are particularly important. Measurements of mean length and upper half mean length can be made rapidly with other instruments, but instruments to rapidly measure short fiber content have not been available until now. Evaluation results show good corre lations between measurements made using conventional laboratory methods and measurements using AFIS.

The objectives of this work were to develop a method to measure the tensile properties of individual cotton fibers and to use the data from the method to study the relationships between the tensile properties of individual fibers and fiber bundles. Mathematical models were developed to predict bundle strength from individual fiber tensile prop erties. The single fiber strength method gives information about the elongation and crimp of cotton fibers. For the set of samples used in this work, the average elongation was 11.8% and the average crimp was 4.8%. Analysis of the single fiber strength data suggests that the average single fiber breaking strength sets an upper limit for the fiber bundle strength. The correlations between fiber strength and yam strength were some what improved by using the average single fiber strength rather than the Stelometer or high volume instrument ( HVI ) bundle strength.

A new instrument for single fiber tensile testing is evaluated and data from two cotton species are presented. The instrument allows rapid accumulation of data that, before inception, were extremely tedious and labor intensive to obtain. Results include tensile strength and percent elongation at different gauge lengths and rates of extension, and an optical measure of fiber diameter or ribbon width as well as an indication of the extent of convolutions.

The microdust and trash monitor (MTM) is described from early exploratory ver sions to the current fifth generation, high-speed, automated instrument for measuring foreign matter in bale or processed fiber. The MTM aeromechanically releases and separates foreign matter, classifies it, and reports its weights as percentages of lint weight.

A new, high-speed, automated instrument for measuring foreign matter including microdust and trash in bale or processed fiber is described. The method uses aero- mechanical release and separation and electro-optical sensing for microdust, trash, and lint. Data are provided proving the correlation of an experimental prototype gin monitor's readings with readings of other methods. Example data for both microdust and trash are given for both gin and textile mill cleaning machinery performance.