Evaluating a pneumatic fractionator for cleaning ginned lint

Authors: Whitelock, Derek; Armijo, Carlos; Hughs, Sidney

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2015
Publication Date: 6/18/2015
Publication URL: http://handle.nal.usda.gov/10113/61723
Citation: Whitelock, D.P., Armijo, C.B., Hughs, S.E. 2015. Evaluating a pneumatic fractionator for cleaning ginned lint. Applied Engineering in Agriculture. 31(3):399-403.

Interpretive Summary: Concern about the amount of short fibers and fiber entanglements in US cotton has prompted efforts to reduce damage to cotton fibers during processing. At the cotton gin, removal of foreign matter is accomplished mainly using cleaners with grid bars and saws that are efficient at removing foreign material, but reduce fiber length and tend to tangle fibers. Research exploring innovative techniques to clean ginned lint while reducing fiber damage has led to evaluations of a pneumatic fractionator that uses compressed air to tumble and fluff ginned cotton lint and scrub it across a set of narrow slots to remove trash. Tests showed that the device cleaned lint about as well as a conventional saw lint cleaner, but damaged the fiber less. The length of fractionator-cleaned lint was similar to lint that was not cleaned or damaged. However, the fractionator produced about the same number of fiber entanglements as the saw-type lint cleaner. The results show some progress towards the goal of cleaning fiber and maintaining fiber quality as well as or better than current technology, and reducing damage.

Technical Abstract: The pneumatic fractionator has long been used to determine foreign matter content of seed cotton at the USDA Cotton Ginning Laboratories. An experiment was conducted to evaluate the pneumatic fractionator as a lint cleaning device. No modifications were made to the standard device, except that air pressure to internal jets was reduced to 276 kPa (40 psi), instead of 517 kPa (70 psi). Seven lint cleaning treatments after normal saw ginning were used: no lint cleaning, one standard saw-type lint cleaner, and cleaning with the fractionator for 5, 10, 15, 20, and 30 seconds. Foreign matter content (2.0 leaf grade and 253 counts g-1 AFIS total foreign matter) and color measurements (12-1 color grade) for the fractionator were not statistically different from the saw-type lint cleaner (2.0 leaf grade, 257 counts g-1 AFIS total foreign matter, and 11-3 color grade). Length measurements of fractionator-cleaned lint were similar to those of lint that was not cleaned and always better than lint cleaned with a saw-type lint cleaner. For example, upper half mean length for fractionator-cleaned, not cleaned, and saw-type lint cleaner fiber was 29.7, 30.0, and 29.2 mm (1.17, 1.18, and 1.15 in), respectively. Also, the fractionator produced about the same number of fiber entanglements as the saw-type lint cleaner. Processing time in the fractionator had very little effect on fiber quality with the exception that the 5 s processing time had the highest levels of foreign matter. These results showed that the fractionator cleaned lint about as well as a saw-type lint cleaner, but maintained fiber length better.