An ordinary fruit paper bag supplying device used for fruit bagging has been designed and preliminarily tested in our previous study. How to open the ordinary multilayer fruit paper bag fully without damage is a concerning problem for the supplying device. The fruit paper bag is extended by the open mechanism of the supplying device in the opening process. Research of contact action effects of rigid open mechanism on the flexible ordinary multilayer fruit paper bag is necessary and has not been reported to date. Based on kinematic analysis of the open mechanism, the slider stoke and slider speed were determined as important influence factors for the bag open effects. Mechanical characteristic parameters of a typical ordinary double-layer fruit paper bag were measured. A rigid-flexible coupled dynamic simulation model consist of rigid open mechanism and flexible double-layer fruit paper bag was constructed. Both simulation and experimental results indicated slider stroke of the open mechanism was an extremely important influence factor for equivalent stress distribution, overall deformation and opened size of the fruit paper bag. Larger slider stroke would cause high rate of broken bag. With increase of slider speed, there was no big difference of the maximum equivalent stress, deformation and opened size of the fruit paper bag. Larger slider speed was positive for bag opening efficiency. Simulation and experiment methods used in the study is helpful for improving application effects of the developed supplying device.
Taking out and opening the ordinary multilayer fruit paper bag for fruit bagging is labor intensive, costly, not efficient, and potentially dangerous to the operator's health. There is a high demand to develop a mechanical device for the operation in Chinese orchards. A novel supplying device based on the manual operated fruit bag case was proposed. The open hand of the supplying device operates like a farmer's hand that can continuously take out a multilayer fruit paper bag one by one, and open it fully from its inside. Mechanism configuration and dimension parameter of the open hand were designed based on preliminary tests. The operation functionality of the supplying device prototype at different driving trajectories and speed was investigated in the study. The laboratory experimental data indicated that driving trajectory was an extremely significant factor for efficiently taking out and opening the fruit bag without sliding off and damage. Driving speed had a beneficial effect on reducing supplying time. With the synchronous driving trajectory and allowable high moving speed, the developed supplying device could achieve more than 90% opening success rate and less than 2-second opening time. The study showed the potential of the developed mechanical supplying device for fruit bagging with ordinary multilayer fruit paper bags.