Analysis of wrapping characteristics between multi-edge toothed cutter and residual film during shredding of the mixture of mechanically recovered residual films and impurities in cotton fields

Cutter wrapping reduces shredding stability and pretreatment quality of the mixture of mechanically recovered residual films and impurities in cotton fields (MRI). The formation mechanism of cutter-residual film wrapping was analyzed, and a simplified instantaneous quasi-steady mechanical model was established. The key influencing factors were identified as the number of multi-edge teeth, the clearance between the moving and fixed cutters, and the rotational speeds of the high- and low-speed toothed shredding rollers. A central composite experimental design with four factors and five levels was implemented, using the residual film wrapping rate as the response variable. Regression analysis of variance was employed to examine the results, leading to the establishment of a response surface model that describes the relationship between the factors and the residual film wrapping rate. The individual effects of each factor as well as significant interaction effects were evaluated. Under consistent experimental conditions, the relative error between the physical test results and the values predicted by the model was 7.46%, demonstrating close agreement. The verification confirms model performance only at the optimized parameter combination. The model applies within the tested parameter ranges after MRI has been prescreened or most soil has been removed. These results provide a basis for anti-wrapping parameter matching in the shredding pretreatment of MRI.