Design and test of automatic bag-feeding packaging machine of potatoes

Potato is the fourth largest grain crop in China. Mechanization operation is also ever-increasing with the largest area under potato cultivation in recent years. Among them, potato bagging has been one of the most important steps in the subsequent storage, transport, and sale during production. However, manual segmentation cannot fully meet the large-scale production needs in the potato industry, due to the low quality and efficiency of current bagging machines. In this study, an automatic packaging machine was designed to integrate the agricultural machinery using plastic woven bags. A series of operations were adopted, such as bag feeding, opening, lifting, covering, and bagging. Four modules were developed as the feeding with an upper pressure roller, the opening with a suction cup, and the lifting and bagging device. Specifically, the forward conveying of the woven bag was realized in the bag feeding device with an upper pressure roller. The openings were separated on both sides of the woven bag using a bag-opening device with suction cups. The woven bags were inserted and then lifted to the position below the hopper. Ultimately, the potato dropping was realized under the clamp bagging device. In addition, the photoelectric sensor was equipped to detect the forward position of the woven bag. A switch sensor of metal proximity was also utilized to detect the position of the bagging arm. A PLC was then used to control each mechanism for the automatic potato bagging. The potato bagging rate and bagging efficiency were improved in the machine. Then, the influencing parameters of key components were determined to combine with the technical requirements of plastic woven bags. With the upper roller pressure, suction cup adsorption height, and adsorption time as test factors, while the bag opening rate and bagging efficiency as evaluation indexes, a three-factor, three-level orthogonal experiment was carried out using Box-Behnken neutral combination design function in Design-Expert. Variance analysis was also performed to clarify the impact of the various experimental factors on the evaluation indicators using the response surface method (RSM). The working parameters were optimized to determine the optimal combination of parameters under the actual operations. The test results show that the bag opening rate of the woven bag was 98.36%, and the bagging efficiency was 68 bags/min when the wheel pressure was 71.0 N, the adsorption height of the suction cup was 80.0 mm, and the adsorption time of suction cup was 1.6 s. There was a stable coordination among the various parts of the bagging machine during operation. The performance indexes fully met the actual working requirements. The findings can also provide a strong reference developing and optimizing the bagging equipment in the potato industry.