# Design and Optimization of a Toothed-Plate Single-Roller Crushing Device for Waste Plastic Film
[PERSON] found that when the crushing roller rotation speed exceeded 1600 r/min, the supported crushing method achieved a crushing length qualification rate exceeding 90%. Moreover, it resulted in a 17.4% reduction in power consumption compared to the unsupported crushing method. [PERSON] [17] researched the cutting blade angle of the rubber crusher. They utilized ANSYS to analyze various blade angles for crushing tools. Simulation experiments demonstrated that a cutting blade angle of 42\({}^{\circ}\) yielded the optimal comprehensive performance. These machines of previous research are effective in crushing hard materials. However, when they are used for the crushing of waste plastic film with the property of high ductility [18], clogging of the crushing components is likely to result because flexible materials often require sharp cutting blades that utilize tearing forces to crush them. For hard materials, the use of sharp cutting blades can reduce their lifespan, and blunt blades are typically used to crush hard materials [19; 20]. There is currently limited research on the co-crushing of flexible and hard materials. Therefore, it is necessary that such research be undertaken for advancement in the field of crushing technology for waste plastic film, as it will increase the efficiency of its resource utilization. In this study, based on previous experimental determinations of the mechanical properties of waste plastic film and crop stalks [21], we have designed a toothed-plate single-roller crushing device for waste plastic film. By coordinating the action of the moving toothed plate and the fixed toothed plate, waste plastic film and crop stalks are first crushed and then torn apart, thus achieving their co-crushing. Following previous research and recycling industry requirements, the crushed film area ranges from 1000 mm\({}^{2}\) to 6000 mm\({}^{2}\), which is conducive to the cleaning and separation of the crushed waste plastic film [22; 23]. Moreover, achieving a low impurity content in the waste plastic film after preliminary cleaning can enhance the quality of waste plastic film recycling. Through kinematic and mechanical analyses of the crushing process, factors influencing the crushed film size and impurity content have been identified, including the feeding velocity, the number of toothed plates, and the crushing roller rotation speed. We used feeding velocity, the number of toothed plates, and the crushing roller rotation speed as test factors and the size qualification rate and the impurity content of crushed film as optimization indexes; a Box-Behnken three-factor, three-level experiment was designed. Finally, through response surface analysis, we determined the relationships between the three factors and the optimization indexes, leading to the identification of the optimal combination of factor parameters. This research introduced an innovative approach to the design and optimization of a crushing device for waste plastic film. The research results can provide crucial technical and equipment support for the resource utilization of waste plastic film.