RESEARCH ARTICLE Modelling the impact of crushing on the strength performance of corrugated fibreboard Mohamad Aiman Jamsari 1 | Celia Kueh 1 | Eli M. Gray-Stuart 1 | Karl Dahm 2 | John E. Bronlund 1 1 School of Food and Advanced Technology, Massey University, Private Bag 11 222, Palmerston North, 4442, New Zealand 2 Advanced Materials, Callaghan Innovation, 69 Gracefield Road, Lower Hutt, 5010, New Zealand Correspondence Mohamad Aiman Jamsari, School of Food and Advanced Technology, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand. Email: a.jamsari@massey.ac.nz This paper presents different ways of modelling the strength of corrugated fibreboard (CFB) subjected to different levels of pre-crushing. The strength perfor- mance was measured through four-point bending loading and edge crush test (ECT). The models used in this study were an analytical solution, an equivalent flute model, and detailed flute geometry models that consisted of idealized sine geometry and real geometry. The study found that the bending performance was dependent on the calliper of CFB rather than the flute geometry. All models showed a similar trend in predicting the drop in bending stiffness as the level of pre-crushing increased, albeit with different absolute value. It was found that the real geometry model of the board predicted ECT performance better than the other models. However, at severe pre-crushing levels (>50%), there was a significant drop in the experimental ECT force not predicted by the models. For these cases, there was evidence of delamination of the flute, a failure mechanism that was not included in any of the models. The analytical solution model provides the quickest prediction but could not predict the crushed ECT performance due to not considering the calliper variable in the equation. The equivalent model showed faster solving time compared with both real and idealized geometry models, although these microgeometry models predicted ECT the most accurately. KEYWORDS bending stiffness, edge crush test (ECT), finite element (FE) analysis, flute profile, orthotropic material 1 | INTRODUCTION Corrugated fibreboard (CFB) is a well-known product in the packaging industry, primarily used as boxes and trays and for cushioning pur- poses. It is lightweight but still possesses high strength due to the structure of the flute. Compared with other paperboard products, it is usually desirable as it is relatively cheaper. The major purpose of corrugated fibreboard in packaging is in protecting the packaged goods from various hazards. The basis of CFB works such that the flute provides the strength and stiffness per- formance, and when anchored to the liners, it will resist bending and pressure from all directions. The flute can be primarily defined based on its height, pitch, and take-up factor. Typically, there are different standard sizes of the flute such as A, C, B, E, and F flutes. Larger flutes are designed to provide strength and cushioning performance while smaller flutes enhance the graphic capabilities. 1 Crushing on CFB can occur during manufacture, conversion, erecting, packing, and distribution. 2 This can damage the flute Received: 24 July 2019 Revised: 10 December 2019 Accepted: 6 January 2020 DOI: 10.1002/pts.2494 Packag Technol Sci. 2020;1–12. wileyonlinelibrary.com/journal/pts © 2020 John Wiley & Sons, Ltd. 1