Study on round rice straw bale wrapping silage technology and facilities

Specific to problems of the existing round bale wrapping machine in China, such as small application scope and failing to satisfy the wrapping demands of round bales of different specifications, a tumbler-type round bale wrapping machine based on wrapping silage with stretch film was designed. By theoretical analysis and preliminary experiments of the corresponding wrapping process, revolving speed of tumbler, speed ratio between tumbler and carrier rollers, and pre-load force of stretch film were determined as experimental factors, while wrapping time and consumption of stretch film per unit mass of round bale were determined as evaluation indexes. Furthermore, quadratic regression orthogonal rotational combination experimental design was adopted to carry out the wrapping experiment. The regression models were set up, and influencing rules of experimental factors on evaluation indexes were also analyzed. The optimal parameter combination scheme was revolving speed of tumbler of 31-32 r/min, speed ratio between tumbler and carrier rollers of 2.6, and pre-load force of stretch film of 20-22 N. Under such a circumstance, the corresponding wrapping time required was 37.7-38.9 s and consumption of stretch film per unit mass of round bale was 3.21-3.46 kg/t. The predicted values and the measured values of evaluation indexes basically coincided with each other and the relative error fell below 5%, which indicated that both the optimized regression models acquired through the wrapping experiment and the relevant parameter optimization results were reliable. To guarantee the quality of rice straw silage, the round bale should be wrapped by no less than five layers of stretch films through the utilization of the tumbler-type round bale wrapping machine. The study results could be used as references for research and development of the round bale wrapping machine.