The use of A-flute, B-flute, AC-flute, and BC-flute corrugated paperboard as a cushioning material

Corrugated paperboard, often referred to as cardboard by those outside the industry, is most often associated with the typical shipping box. Research has proven that cushioning is another possible packaging application for corrugated paperboard. Corrugate is easily accessed, obtained from a renewable resource, and easily recycled all of which appeal to the increased interest in the use of sustainable materials. Most research related to corrugate as a cushioning material has been performed using single-wall, C-flute corrugated paperboard.The purpose of this research was to create cushion curves for A-flute, B-flute, AC-flute, and BC-flute corrugated paperboard using the stress energy method. Cushion curves were created and presented by the common industry practice of drop one and the average of drops two - five. However, it was determined that cushion curves for corrugate materials should likely be presented as drop one, drop two, and the average of drops three-five due to large differences between drops two and three-five.The stress-energy method was used to create the cushion curves, which required the use of a trendline to characterize the material. The type of trendline applied to the dynamic stress vs. dynamic energy graph was examined. Linear, exponential, third order polynomial and fifth order polynomial trendlines were applied to all flutes and conditions. Exponential line fit showed comparable r-square values, especially after drop one. However, for drop one, a polynomial line-fit is likely still required due to lower correlation coefficient (r-squared) values.The homogeneity of lines for all flute sizes was compared using an exponential line fit. All flute sizes were determined to be statistically different from one another.A-flute, B-flute, and BC-flute cushions were tested at both standard and high humidity conditions to determine if there was a statistical difference in the cushion curves. All flute sizes conditioned at high humidity conditions were determined to be statistically different from the same flute size at standard conditions. Also, all flute sizes showed lower cushion effectiveness under high humidity after multiple drops.