Theoretical Analysis An Experimental Research On The Key Technology Of Corn Plastic Film Recycling

In the late 1970s, plastic mulching cultivation techniques can increase temperature and soil conservation,shorten the required time for the crops growth and suppress weeds growth while increase yield and so on, which have raised "white revolution" in the agricultural production and have been widely used in many provinces and autonomous regions in our nation.However, the years of use mulch in soil without recycling timely has seriously damaged the farmland ecological environmentAt present the research of plastic recycling machine is mainly on crops such as cotton and vegetables, but on large root crop plastic recycling such as corn, tobacco, sugar beet, there is no mature recycling machinery. This paper has taken corn crops as research object and carried out test study on the physical properties of different thickness of film, and designed double-disc type to cut film to solve the influence that big root crops on plastic recycling.Current mature mechanical structure were borrowed to design the corn plastic recycling machinery.The theoretical calculation and analysis was respectively carried out on the double-disc mechanism and side film shovel. Finally, the optimum and kinematic parameters were determined through field experiments, and the main research results are as follows:(1) Through the investigation of our national maize agricultural cultivation and current situation of the plastic recycling equipment at home and abroad, the design of corn plastic recycling machine was determined, and double-disc type mechanism of cutting film was put forward to solve the influence that big root crops on plastic recycling, at the same time the mature mechanism for recycling plastic film was used, such as elastic picking film roller, unloading film mechanism, walking mechanism.(2) Studied and compared the change rule of tensile properties of plastic mulch by different thickness,different time and different position. Because tensile properties were affected more by the factors such as UV rays and wind. The results of field experiments showed that when recycling the used plastic film,the tensile strength of used film had dropped obviously about from 30 to 60 days after laid, and cotton plants have obstacle affects on UV rays and wind.The tensile properties of plastic strains at the plant side CP(Close to the plant) were obviously far better than that of the plant side FP(Far from the plant).The maximum tensile force of longitudinal direction are about a third higher than that of the transverse direction,so the design of recycling plastic machine components were along the laying direction of plastic film as far as possible.The tensile properties of 0.01 mm film have much better promotion than that of 0.008 mm, and collection difficulty was relatively lower down,which would help reduce farmland plastic residues.However,through the field tests on 0.01 mm plastic film in YuLi County, Korla,simple winding way can not be used on plastic recycling and the tensile properties didn’t satisfy the needs enough.(3)The contrast test analysis were carried out on side-film recycling mechanism.Three different structures of side-plastic shovel was designed, opener,wings shovels and single wing shovel.Stress analysis were conducted respectively on three different structures of side-film shovels. Through the comparison of the theoretical calculation and field test, the results showed that single wing spade had better effect on side-film recycling although it needed the largest stress,which can effectively solve the problem of side-film recycling,so the design of loosening shovel should used single wing shovel.(4)The kinematic and dynamic analysis was carried out on the double-disc type mechanism and the kinematics and dynamics model was established.The structure size of double-disc was determined about agricultural technology of maize planting, the dynamics and kinematics research was conducted on cutting disc. Then basic parameters of the disk were determined, and the trajectory and regularity of disc was made by theoretical analysis.The force state of a double disc was analyzed on cutting film and digging stubble test bench.The Ansys software was used to analyze the stress distribution. The maximum stress point occurred at the joint of each disc group connected with its column and the maximum stress value was 138.6Mpa.Modal analysis of the vibration frequency of 19.531 Hz and field simulation analysis of the large difference between two 27.952 Hz, resonance will not occur,which confirmed that the structural strength and the functional design was satisfied the need.(5)Designed and made test-bed of double-disc cutting film and the field experiments were carried out to verify the structure strength and operation performance of the test bench. The results showed that when the test bench was working,the optimum factor combination was the depth into soil with 15cm, working velocity with 4.04km/h and the interval with 12cm.The Donghua Test software was used to test the stress and the stress changing rule of test bench was determined in different soil depth with 10 cm,15 cm,20 cm, then concluded that the space at the joint of each disc group connected with its column had bigger stress.the stresso was227.942Mpa and it was smaller than the yield strength of ordinary material 235Mpa.In the filed test, the test-bed satisfied the structural strength and the functional need.