Compression strength of ventilated corrugated paperboard packages: Numerical modelling, experimental validation and effects of vent geometric design

Ventilated corrugated paperboard (VCP) packaging is used for transporting fresh produce through a distribution system that requires maintaining a balance between uniform cooling of the produce and mechanical integrity of the package. A validated finite element analysis (FEA) model capable of predicting the compressive strength of two commonly used VCP packages is developed; the MK4 with higher length-to-height ratio and vent area compared to the MK6. The validated model was used to study the effects of vent geometric parameters such as vent height, shape, orientation, number and area on the strength of the packages. FEA results were in good agreement with the experimental results with a difference of 4.7% for MK4 and 8.2% for MK6. The MK6 had higher compression strength than MK4 with a difference of 11% and 17% at standard and refrigerated conditions, respectively. Results showed that the compression strength was lower by 11% and 16% respectively, for MK6 and MK4 packages when stored at low temperature (0 °C and 90% Relative humidity (RH)) compared to standard conditions (23 °C and 50% RH). With an increase in vent area from 2 to 7%, buckling load decreased by 8% for MK4 and by 12% for MK6. A linear correlation was observed between vent height and buckling load with R2 values of 0.8215 and 0.9717 for MK4 and MK6 packages, respectively. Results showed that vent number, orientation, and shape affected the buckling of the packages. Rectangular vent holes better retained the strength of the packages. Irrespective of the vent design parameters studied, the MK6 had higher buckling load.