Evaluation of seed cotton cleaning equipment performane at various processing rates

The processing rate per unit width of seed cotton cleaning equipment–cylinder cleaners and stick machines– recommended by manufacturers is 4.9 to 8.2 bales h-1 m-1 (1.5 to 2.5 bales h-1 ft-1). Survey data has indicated that many gins exceed this processing rate. Little research has been conducted with picker-harvested cotton, and higher rates that have been achieved in commercial gins have not been tested. Two independent experiments were performed to evaluate the effects of processing rates significantly higher than recommended on the performance of the cylinder cleaners and stick machine. Seed cotton was processed through a typical sequence of gin machinery: cylinder cleaner, stick machine,cylinder cleaner, extractor-feeder, gin stand, and lint cleaner. The quantity of material removed by each cleaner was measured and the fiber content of the waste was determined. Foreign matter content of the seed cotton and ginned lint and fiber quality parameters were also measured. The first study tested four cultivars of cotton harvested in 2008. The second experiment tested two cultivars harvested in 2009 at two seed cotton moisture levels. Lower processing rates increased the amount of material removed by the first stage cylinder cleaner and stick machine. Five of six cultivars tested had low fiber loss from the seed cotton cleaning system, while the other cultivar had an average fiber loss of 3.37 kg bale-1 (7.43 lb bale-1). Processing rate did not have a statistically significant effect on fiber loss; although a trend of increasing fiber loss from the stick machine at higher rates was observed for the cultivar with higher fiber loss. No effect on fiber quality due to processing rate was observed. More research is needed to determine the economic impact of higher than recommended processing rates, as extractor-feeders and lint cleaners may compensate for poorer cleaning, but were not tested at rates typically used in commercial gins.