Use of a Rotor Spray System for Moisture Addition to Cotton Lint

Tests were conducted using a rotor spray system to apply moisture in the form of fine water droplets to cotton lint at the lint slide just before bale packaging. Two studies were conducted, one in which bales were stored for 6 months and another in which bales were stored for 15 months. For the first study, initial cotton lint moisture content averaged 5.1% and ranged from 4.4% to 5.7%, wet basis, and for the second study the initial moisture content averaged 5.5% and ranged from 5.1% to 5.9%. For the 6-month storage test, five levels of moisture addition were studied, including average moisture levels of 6.3%, 6.5%, 7.0%, 7.7%, and 7.9% moisture (just after rewetting), in addition to bales with no additional moisture added. For the 15-month storage test, three levels of moisture addition were studied, including 8.0%, 8.4%, and 10.0% moisture (just after rewetting). In both studies, cotton quality degradation was determined after each of the respective storage periods. No significant changes were found in HVI micronaire, strength, length, or uniformity or any properties measured with the Advanced Fiber Information System. At moistures of 7.5% and greater, the color +b value decreased slightly and the decrease was statistically significant. When considering the moisture range used in this study, results are consistent with earlier studies using atomizing spray nozzles, therefore recommendations for using a rotor spray system for adding moisture to cotton fiber at the lint slide should be the same as those for using an atomizing spray nozzle system. Thus, in order to minimize color degradation during storage, cotton lint moisture should be less than 7.5% wet basis (8.0% dry basis) when the bale is formed.