Zhang J.,China Agricultural University |
Zhang J.,Xingjiang Academy of Agricultural science |
Wang X.,Xingjiang Academy of Agricultural science |
Zhang L.,Xingjiang Academy of Agricultural science |
And 8 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015
Plastic mulching technology has brought huge economic benefits, while the residual plastic film produced series of serious problems such as pollution on land. A large number of plastic recycling is becoming urgent and important task in our country. A large amount and long term of used plastic film on soil has caused great serious influence on the high quality of farmland planting, crop growth, the rural ecological environment and new rural construction, which has attracted more and more attention. Now, the research on the recovery mechanism is limited to equipment of plastic film enwinding recycling, and there are few studies on the variation rule of the tensile properties of used plastic film and the impact. During our practical research work, performance such as unstable recycling capability, low film recovery rate and work parts deformation often appears in the used plastic film recycling. To address these problems, we carried out some field experiments. The series tests were conducted in Da West village, YuLi County in Korla, Xinjiang from March to October in 2014, including the test of tensile properties of plastic film changes in different thickness, time and direction by 0.01 mm plastic film enwinding recycling. The methods were as follows: Firstly, each sampling point, which are not very far with previous sampling point, were carried on hard, dry and flat land, and taken complete plastic film without damage. The sampling work should be conducted on the large space line, and the sampling point be as close as to the plants. Four plastic films with different thickness were selected with the width and length were 600 mm and 200 mm respectively. The tensile properties of plastic films were tested with CMT6000 electronic universal testing machine. Secondly, three-dimensional modeling and motion analysis were completed for the machine of retrieving by solid works software. According to the measure of maximum tensile force with payback time, the tensile force was contrasted with the sum of ground and slope in wrapping recovery. The result showed that the maximum tensile force was less than the twine. Finally, the recycling test was carried out with wrapping in 0.01 mm film, but the film fractured from time to time. The wrapping recovery could not meet the demand of 0.001 mm film. The results of field experiments showed that the tensile strength of used plastic film had dropped obviously for the wind and ultraviolet irradiation after 30 to 60 days laying the plastic film. The maximum tensile stress of 0.01 mm plastic film was 1.52 N, which was close to the plants and 1.305 N, which was far from the plants; and the stress was 1.4 times and 1.22 times of 0.008 mm plastic film, respectively. The maximum tensile strength of mulch film on the longitudinal direction was generally higher about 1/3 than the transverse direction of the mulch film. So the recycling aparts should be along the direction of laying the plastic film. The tensile properties of 0.01 mm plastic film had made a certain improvement compared to 0.008 mm, which were some helpful for plastic film recycling. However, by the theoretical calculation and field test of the experiment on 0.01 mm plastic film enwinding recycling, the tensile properties of 0.01 mm plastic film were not satisfied with simple winding way. This study revealed the rule that the plastic tensile properties were affected by UV, etc. at different times, thickness and direction, which would provide theory basis for the development of the plastic film recycling machine. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.