Evaluating newly designed lint cleaner grid bars to remove seed coat fragments

Authors: Armijo, Carlos; Delhom, Christopher - Chris; Whitelock, Derek; Hughs, Sidney; GILLUM, MARVIS - Retired ARS Employee

Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/21/2016
Publication Date: 12/30/2016
Publication URL: http://handle.nal.usda.gov/10113/5642515
Citation: Armijo, C.B., Delhom, C.D., Whitelock, D.P., Hughs, S.E., Gillum, M.N. 2016. Evaluating newly designed lint cleaner grid bars to remove seed coat fragments. Journal of Cotton Science. 20:356-366.

Interpretive Summary: Seed coat fragments (SCF) cause spinning problems and undesirable defects in finished goods. An experiment was conducted to remove SCF at a saw-type lint cleaner using newly-designed grid bars. The test consisted of five experimental grid bar designs, one control grid bar design, and a treatment that contained no lint cleaning for comparison. The experimental grid bars varied the angle from the sharp toe of the grid bar (or the angle from vertical). Two types of cotton were used, a common upland cultivar and a cultivar known to have a fragile seed coat that breaks easily and contaminates lint with SCF. Results showed significant differences in fiber properties between the cultivars. Fiber from the fragile cultivar was shorter, less uniform, and contained more short fibers, neos, and seed coat neps (SCN). There were differences in fiber properties among lint cleaning treatment, but those differences were between the treatment that contained no lint cleaning and the grid bar treatments collectively. Visible foreign matter in ginned lint was not different among lint cleaning treatments. Both AFIS seed coat nep count and a manual count of SCF, which were used as an indicator for seed coat fragments, were not different among lint cleaning treatments. The least aggressive grid bar design (rounded tip) had the lowest amount of foreign matter in the lint cleaner waste. As expected, fiber in the lint cleaner waste was shorter, and contained more short fiber and neps than fiber in the bale, but SCN count in the lint cleaner waste also was not different among grid bar designs. High-speed videography showed that SCF were not removed by colliding with the grid bars, but were actually drawn back into the lint stream by attached fiber. Other means to separate SCF from ginned fiber are being investigated.

Technical Abstract: Seed coat fragments (SCF) cause spinning problems and undesirable defects in finished goods. An experiment was conducted to remove SCF at a saw-type lint cleaner using newly-designed grid bars. The test consisted of five experimental grid bar designs, one control grid bar design, and a treatment that contained no lint cleaning for comparison. The experimental grid bars had angles from the sharp toe of the grid bar (or the angle from vertical) of 105°, 60°, and 45°; a grid bar design that had a rounded tip with a 0.79-mm (0.031-in) radius; and a grid bar that had one edge and a radius of 90°. The 105° and 60° grid bars were unique in that they had a second edge a short distance from the toe of the grid bar. Two types of cotton were used, a common upland cultivar and a cultivar known to have a fragile seed coat that breaks easily and contaminates lint with SCF. Results showed significant differences in fiber properties between the cultivars. Fiber from the Acala cultivar was 16% longer, 2.1 percentage points more uniform, and contained 3.5 percentage points less short fiber, 7.6% fewer neps, and 40% fewer seed coat neps (SCN). There were differences in fiber properties among lint cleaning treatment, but those differences were between the treatment that contained no lint cleaning and the grid bar treatments collectively. Visible foreign matter in ginned lint was not different among lint cleaning treatments and averaged 2.7%. Both AFIS seed coat nep count and a manual count of SCF, which were used as an indicator for seed coat fragments, were not different among lint cleaning treatments and averaged 42.8 counts per g and 46.7 counts per 5 g, respectively. The least aggressive grid bar design (rounded tip) had the lowest amount of foreign matter in the lint cleaner waste (47.1%). As expected, fiber in the lint cleaner waste was 19% shorter, and contained 133% more short fiber and 34% more neps than fiber in the bale, but SCN count in the lint cleaner waste also was not different among grid bar designs and averaged 13.0 counts per g. High-speed videography showed that SCF were not removed by colliding with the grid bars, but were actually drawn back into the lint stream by attached fiber. Other means to separate SCF from ginned fiber are being investigated.