Study On Cushioning And Anti-vibration Technology Of Fresh Fruits And Vegetables In Multi-temperature Zone Express Packaging

In this paper,a new type of multi-temperature zone fresh fruit and vegetable express incubator is designed,and the optimum mass ratio of refrigerant to fruit and the effect of two cushioning pads,mesh and stretch lining,on the anti-vibration performance of fruit are studied under different parameters.The mathematical model of stretch lining and damage area is established.The drop impact characteristics of the thermostat.The optimum mass ratio of refrigerant to fruit can be determined by temperature control experiment of different mass ratio of refrigerant to fruit under the condition of setting holding time and outside environment.The optimum mass ratio of refrigerant to fruit can not only keep the temperature of fruit in the range of setting temperature within 24 hours,but also minimize the occupancy of refrigerant in the box space.According to the experimental data,the optimum mass ratio of cold storage agent to mango is 0.6 7:1,and the optimum mass ratio of cold storage agent to pear is 0.75:1.The temperature of the fruit in the box can be kept above 24 hours at 23?/50%RH,respectively.Vibration cushioning experiments of different liners were carried out in the heat preservation boxes with the optimum mass ratio of cold storage agent.The results showed that different thickness of fruit net,different thickness and different height of tensile liner had an effect on the cushioning effect of fruit.The buffer effect of 4mm is the worst,similar to that of no cushion,and similar to that of mesh when the thickness is 6mm and 8mm.The tensile lining was selected as the research object,and the cushioning and anti-vibration performance of the express box was tested under different lining thickness and different lining height.The results showed that the higher the tensile lining was,the better the cushioning effect was,and the cushioning effect was the worst when the tensile lining was 8 mm thick and 40 mm high and 8 mm thick and 20 mm high.The results showed that the protective effect of tension lining on the surface and fruit hardness of pear was better than that of net lining under similar conditions,that is,the area of surface damage was less,the decrease of hardness was less,and the protective effect of tension lining on pear fruit hardness was better than that of net lining,but the protective effect of tension lining on the surface hardness of pear fruit was better than that of net lining under similar conditions.The effect of dynamic lining on the surface of mango is slightly less than that of net cover.According to the specific test results,the mathematical model of vibration time-liner thickness-damage area and vibration time-liner height-damage area was established,and the corresponding equations were obtained.Drop impact test was carried out to verify the cushioning performance of the whole package under the condition of fruit protection with a certain thickness and height liner.The results showed that the express packaging box and cushioning pad had better heat preservation and cushioning performance,and could be used as the express transportation packaging of fresh fruits and vegetables.