Abstract:A method based on electrostatic adsorption for grading removal of residual plastic film in machine-harvested cotton was proposed. The machine-harvested cotton of Xinluzao No.26 planted in Alaer region of Xinjiang was the research object. According to the correlation between the degree of polarization charge and the curved form of the residual plastic film in machine-harvested cotton, the characteristics of various residual plastic film in machine-harvested cotton were extracted by image processing, and then the residual film was graded by clustering algorithm and divided into Ⅰ, Ⅱ and Ⅲ grades. Then the electrostatic adsorption separation platform was constructed, and factors of different charge times, flying speed and polar plate voltage of machine-harvested cotton with different grades of residual plastic film were tested. Taking the impurity removal efficiency as the index, the optimum combination of the external influencing factors of the corresponding grade residual plastic film was found in order to achieve the maximum separation between the residual plastic film and machine-harvested cotton. The results indicated that the factors affecting the removal impurity efficiency were: charge time, flying speed, and polar plate voltage. The optimum charging time of machine-harvested cotton with grade Ⅰ residual plastic film was 24s, flying speed was 4.7m/s, plate voltage was 39kV, and separation rate was 96.2%;grade Ⅱ: charging time was 29.8s, flying speed was 5.8m/s, plate voltage was 37.6kV, separation rate was 98.1%;grade Ⅲ: charging time was 30.1s, flying speed was 3.5m/s, plate voltage was 46.2kV, and the separation rate was 97.2%. The results showed that the method of grading removing residual film based on electrostatic adsorption was feasible and met the needs of practical development.