How Small Is a Point Load? A Preliminary Study of the Deformation and Failure of Cartons Subjected to Non-Uniform Loads

Abstract

Consumer packaging made from carton board is subjected to a variety of loads as it moves through the value chain. Packaging designers need tools for predicting the strength of packages under these loading conditions. For evenly distributed loads, there are methods for measuring and estimating compression resistance that can provide useful guidance. For loads concentrated to a small area, little work has been published. The aim of this preliminary study is to aid the development of a future test method for point loads by investigating how the size of the load application site influences the mechanical behaviour of the package. Rigid spheres of a range of sizes were used to compress packages. Small spheres gave rise primary damage in the form of a vertical yield line and secondary damage in the form of a parabolic yield line. Larger spheres produced a series of parabolic yield lines of increasing size. No vertical yield line appeared for the larger spheres. The larger spheres showed a stiffness transition at a displacement that could be estimated by considering the geometry of the test.

Evaluating the use of a tactile sensor for measuring carton compliance

“…Testing packaging in a manner similar to how humans gather kinaesthetic information can be achieved by com-pression between rigid objects (Eriksson and Korin 2017). As discussed above, this information is not what is mainly used when humans judge compliance.…”