Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: January 5, 2006
Publication Date: June 9, 2006
Citation: Baker, K.D., Hughs, S.E. 2006. Spindle design effects on cotton quality. In: Proceedings of the Beltwide Cotton Conferences, January 3-6, 2006, San Antonio, Texas. 2006 CDROM. p. 420-424. Interpretive Summary: Spindle picking has become the preferred method of harvesting most cotton in the U.S. Improvements to the cotton harvester have primarily focused on increased speed in order to reduce the cost of harvesting and reducing head weight. As the spindle speed has increased, cotton fibers can wrap more tightly around the spindle. As spindle diameter decreases, cotton fibers will wrap around the spindle more and will also become tighter on the spindle. As spindle length decreases, cotton plants must be further compressed as they pass through the picking zone. These changes have resulted in a general decrease in cotton fiber quality, particularly regarding spindle twists, preparation, and neps.
Technical Abstract: Three cotton varieties were grown under furrow-irrigated conditions in southern New Mexico and hand-harvested in a way that kept individual bolls intact. The cotton bolls were conditioned in a controlled atmosphere and then subjected to a single cotton picker spindle operating at a speed of 1000 - 3000 rpm. Two spindle designs were studied, a ½” round, tapered, barbed spindle and a 3/16” square spindle that was straight and smooth. Mass measurements were taken to determine the portion of seed cotton not picked and the portion that would fly off and not stick to the spindle. A force gage was used to determine the peak force that was needed to pull the seed cotton from the spindle. Moisture content of the bolls was 9 to 10 % d.b. Results showed that the smaller, straight spindle was more aggressive in removing cotton from the boll. There was approximately twice as much flyoff from the barbed spindle than from the smaller straight spindle at any given speed. Flyoff also increased exponentially for each spindle type as the speed was increased for both spindle types. The peak force required to remove the seed cotton from the spindle ranged from 50 to 100 % more for the smaller straight spindle than from the barbed spindle. For both spindles, the peak force requirement was approximately doubled each time the speed was increased by 1000 rpm, indicating an exponential relationship between speed and wrap tightness.