Mechanical analysis and contrast experiment on collecting residual plastic film with different side-film shovels

Abstract: In the pollution controlling of the residual plastic films in the farmland, due to the lack of preferable side-film shovel mechanics in autumn plastic film recycling, the side-film can't be recycled by the side-film shovel but be buried under the ground surface. A large amount of residual plastic film into soil due to long-term using film on the crops has caused great serious influence on the high quality of farmland planting, crop growth, the rural ecological environment. The side-film accounted for 16% of the whole plastic film, which would result in the lower recovery rate for plastic film recycling and the recovery rate was generally maintained at about 80%, nearly 20% of the plastic film still remained in the soil, which caused definite pollution to the soil and the environment. Current research on the recovery mechanism is limited to the equipment of plastic film enwinding recycling itself. In order to solve these problems, the more widespread used mechanics for collecting the side-film was chosen such as furrow opener and double wing shovel. Then the mechanical analysis of one wing shovel newly designed was carried out with opener and double wings shovel. The forces of collecting the side-film were compared among three different structural shovels and the field contrast tests were carried out in Yuli county, Korla city in Xinjiang. The working performances of different side-film collecting shovels were compared in the field test. The three key factors were assessed about the integrity rate, film recovery rate and no heap soil phenomenon of residual plastic film. Results showed that the force of the side-film shovel taken was related with the angle into soil and blade length of the side-film shovel during the shovels picking the side-film. According to analyze the force of three types of shovels, we gained the balance equation, the equation involved some kinds of forces, such as the friction along the slant, the normal load along the slant, the shear force of soil internal shear failure, the friction force between the internal soil and the accelerating force of soil movement. Theoretical analysis of three side-film shovels showed that the force of one wing shovel was maximum while the stress of furrow opener device was minimum, the stress of double wing shovel was relatively reasonable. However, the performance effect of the one wing shovel was the best in the field testing although the force of one wing shovel was maximum. The integrity rate of the side-film was reached at 100%, the film recovery rate was at 95.4%, and without obstructing the soil in working performance. Taking the prominent operational effectiveness into account, the one wing shovel was highly recommended as autumn residual side-film recovery machine of the plastic film collecting structure. The research results can be provided a reference for the design of the side-film collecting mechanism section during the whole residual film recovery machine and also provide theory basis for the development of the plastic film recycling machine.