バルクコンテナ輸送におけるウンシュウミカンの振動特性および力学的特性

抄録

　The vibration characteristics, contact load, and breaking strength of Satsuma mandarin stacked in a triple-wall fiberboard box under a vibration treatment (2-30 Hz, 0.6 G) were investigated for evaluating the feasibility of using a bulk container (BC) for fresh produce transportation.

　Acceleration transmissibility (AT), which is the value obtained by the acceleration of individual fruit divided by that of the vibrating table, was used as the index for vibration characteristics of BC and carton box. The maximum AT values for both BC and carton box were recorded for the top layer mandarin. This maximum value of AT of the top layer fruit, at 1,000 mm from the bottom as the maximum height for the practical use of BC, was 3.6 times of carton box.

　As for vibration load, when the number of stacking increases, BC contact load would increase with lower peak frequency.

　Breaking strength values, obtained by the compression test for individual fruit, were dependent on several factors such as compression direction, growth conditions, and storage period, and the addition of artificial scratches. The value of compression for 'top and bottom direction' was higher than that for 'equatorial direction'. The breaking strength value of greenhouse-grown fruit with scratches was half of that without scratch. Furthermore, stored fruits with and without scratches showed significantly higher breaking strength value than that of greenhouse grown type.

　Breaking strength is determined by the mechanical characteristics of fruits and compression speed. Therefore, it is crucial to prevent the inclusion of damaged fruits in the BC and to set stacking heights based on the mechanical characteristics and transport conditions to ensure safe transportation of Satsuma mandarin using BC.