Design and Experimental Study of an Adjustable Wrapping Machine for Rice Straw Bales of Different Sizes

China annually produces over 210 million tons of rice straw; however, its utilization as feed remains low due to the scarcity of supporting equipment. In feed production, wrapping straw bales with plastic film is crucial for accelerating degradation. Given the diverse types of straw balers, a variety of wrapping machines are required. This study presents the design of an adjustable wrapping machine capable of handling straw bales with diameters ranging from 400 to 1200 mm and lengths between 500 - 1000 mm. Wrapping time, coefficient of variation, and elongation rate were selected as key evaluation indicators. Experimental results demonstrate that all performance metrics comply with industry standards for straw bale machinery, indicating the machine's practical feasibility and reliability in agricultural applications.