Behaviour of Multi-Layered Corrugated Paperboard Cushioning Systems under Impact Loads
This paper presents some of the latest results of a research project aimed at using composite corrugated paperboard structures for protection of products against mechanical shocks and vibration during transportation and handling. Specifically, the behaviour of multi-layered corrugated paperboard (MCPB) under shock loading is investigated. Conventionally, packaging cushion design requires the determination of the maximum expected shock levels or equivalent drop which are usually determined from statistical analysis of original field measurements. With this approach, it is generally acknowledged that the cushioning element is engineered to provide adequate protection for statistically likely events but not for extreme events with low statistical likelihood. It is reluctantly accepted that, should it occur, the latter will result in damage to the product. MCPB can be formed with a broad range of compressive characteristics and with various proportions of elastic and plastic behaviour. The objective of this experimental investigation was to determine the optimum elastic/plastic proportion to extend the protective range to include large shock levels. The experimental results obtained include the effects of compression history on the stress-strain properties of MCPB as well as the behaviour of the material in both virgin and pre-compressed form under impulsive loads. The mechanism of deformation of the corrugations (flutes) was studied using high-speed video equipment. The complex acceleration signals produced during deformation of the composite corrugated paperboard cushions under shock loading were analysed by means of the shock response spectrum. Experiments have shown that inserting a sacrificial crumple element of virgin corrugated paperboard at the optimum contact area ratio dramatically lowers the overall level of the resulting shock response spectrum. This has the effect of increasing the allowable drop height for a limited number of extreme events. The main conclusion of the research is that MCPB in both virgin and pre-compressed forms can be combined to provide significantly enhanced protection to products against mechanical hazards during distribution.
J.M. Dulieu-Barton and S. Quinn
M. A. Sek and V. Rouillard, "Behaviour of Multi-Layered Corrugated Paperboard Cushioning Systems under Impact Loads", Applied Mechanics and Materials, Vols. 3-4, pp. 383-390, 2005