Does flute angle influence box performance?

Abstract

In the production of boxes, it is customary to align the flutes vertically, corresponding to a 0° flute angle. This configuration is widely believed to yield optimal compressive strength, despite existing evidence from corrugated flute boards and boxes that challenge this assumption. The present study investigates the hypothesis that non-vertical flute angles do not significantly compromise box compression strength and may potentially offer enhancements in other performance characteristics. Regular slotted container boxes (385 × 238 × 300 mm) constructed from single wall C-flute board were used in this study. Ten flute angles were selected for box level testing: 0°, 5°, 7.5°, 10°, 12.5°, 15°, 20°, 30°, 45° and 60°. Samples of converted board were subjected to edge crush testing (ECT) following TAPPI T-811 and four-point-bending following TAPPI T-820. Box crush testing (BCT) followed NZS 1301.800 2006 (New Zealand Standard). Component testing results were consistent with previous studies. Outcomes showed a general linear reduction in ECT with increasing flute angle, and nonlinear relationships between flute angle and bending force and stiffness. At the box level, peak load did not decline significantly between 0° and 45°, however 60° flute angles had significantly lower peak loads (α = 0.05). At certain angles, notably 10° and 30°, less variation in peak load was observed. BCT force and stiffness of the box significantly improved in terms of median and variation at 10° and 30°. Therefore, a flute angle of less than 45° does not significantly reduce compression strength.