Experimental Research on a Needle Roller-Type Electrostatic Separation Device for Separating Unginned Cotton and Residual Films

In the mechanized harvesting of cotton in Northwest China, problems result from the presence of a residual film, and it is difficult to remove the residual film in the cotton processing stage. In this study, a needle roller electrostatic separation device was designed for use with unginned cotton residual films, and a series of experiments was carried out. Through force analyses and charge testing of the seed cotton and the residual film, a theoretical basis was provided for separating them. Taking the residual film separation rate as the response index, the optimal parameter combination was determined with a response surface analysis of three factors and three levels, and a mathematical model was established. The test results showed that the optimal parameter set included a 25.3° corona electrode angle, a 172.3 mm corona electrode distance, and a 5.25 W discharge power. After optimization of the parameters for separation, the average residual film separation rate was 91.7%. This research provides data and technical support for the design of the machinery and the selection of the parameters used in treating machine-picked cotton and separating the residual film.