Performance of a Cotton Gin Machine that Removes Plastic Contamination from Seed Cotton

Abstract

A commercial cotton contamination cleaner developed and used to combat the plastic contamination problem in Chinese cotton was tested to compare its performance at removing typical plastics found in U.S. cotton to that of conventional cotton gin seed cotton cleaners. Seed cotton “spiked” with pieces of shopping bags, single-layer non-tacky round module wrap (RMW), and three-layer RMW of various sizes was introduced into the machines. Overall, the contamination cleaner was more effective at removing plastic contamination than a conventional cotton gin stick machine and inclined cleaner. Increasing the airflow to the contamination cleaner improved plastic removal. Overall capture of plastic across all sizes and types increased from 16 to 48% when airflow was increased from 17,500 to 30,200 m3/hr (10,300 to 17,800 ft3/min). However, seed cotton captured with the plastic also increased from 1.4 to 34 kg (3 to 75 lb) per bale. Shopping bag material and one-layer non-tacky RMW (lighter, pliable) were more effectively removed than three-layer RMW (heavier, stiffer), and smaller plastic pieces were more effectively removed than larger pieces. All the machines tested removed about the same amount of cotton trash (about 13.6 kg or 30 lb per bale).