Washboarding of corrugated cardboard

The aims of the thesis were to study how washboarding (the undulations present on the surface of corrugated cardboard used to manufacture boxes) relates to the mechanical properties of paper and the board manufacturing conditions and to examine the impact of washboarding upon the structural integrity and printability of corrugated cardboard packaging. A digital image profilometry technique was developed to measure the washboarding profiles of corrugated board. This technique was used to measure the washboarding depth and profiles for a range of corrugated boards, some constructed manually and some machine manufactured. This enabled a study into how a change in the mechanical properties of paper and glue affect washboarding depth. The effect that the speed of machine manufacturing had upon the degree of washboarding was also determined. A study of how environmental conditions affect washboarding geometry was undertaken. The effects of the extent of washboarding upon a range of board performance measures were tested empirically and modelled using Finite Element Analysis. These were edgewise compression testing (ECT), three-point bend, and MD-Shear (an Amcor Ltd. proprietary test). A method was developed to measure full-tone print coverage of corrugated board and was used to study how washboarding affects the printing quality of corrugated board.