段ボール箱の含水率を指標とした胴ぶくれのリスクマネジメントの提案

摘要

段ボール箱の材質を決定する上で圧縮試験（JIS Z 0212）は最も重要な試験項目の一つであり，JIS Z0200　包装貨物一評価試験方法通則には圧縮試験における負荷係数が記載されている。内容品が流動体でなく，段ボール箱の一部または段ボール箱だけで荷重負担する場合，負荷係数は3～5で圧縮試験を行うことが示されている。%The one-year experiment of storage environment shows that when exceeding 11% of water content, a corrugate box which designed with 3-5 safety margin ratio bulges. Several corrugated boxes under different conditions were studied to find out how water content influences compression strength and bulging of the boxes. When exceeding 80% R.H., water content of the corrugated box reaches 11%. Under such circumstances, compression strength of the box rapidly deteriorates. The stacking test for the empty box with 0.20-0.33 load ratio also shows that it rapidly bulges when its water contents exceeds 11%. In order to prevent extreme bulging and buckling with high moisture content, we should not only to control with given safety ratio derived from experiences, but also to improve risk management based on the knowledge about real storage conditions and water content of the boxes.