The Study of the Hidden Bearing Area: Comparison Between Flat and Corner Cushion Shock Test Performance
Throughout history, cushioning material has been used widely in protective packaging design. Various cushioning materials included wood, paper, cloth, paperboard, molded pulp, plastic, and metal. However, the most popular and most effective since the last century is polymer plastic foam as protective cushioning packaging material. It has been comprehensively used for high-shock, compression, and vibration-sensitive products.
Over the past 60 years, scientists and engineers have a come a long way in both packaging-related academics and industries. A new series of testing standards was developed (ASTM D1596 and ASTM D4168) building up the cushion curve in terms of various foam materials, density, thickness, and drop height. Along with these standards came sophisticated engineering-cushion-design methods (Lansmont Six Step Method for Cushioned Package Development) that were developed to achieve the optimal and cost-effective transport solution.
However, due to the testing limitation of 90-degree shock impact, traditional cushion-curve methods lacked consideration of both the hidden bearing area in the corner-cushion design as well as the realistic and economical cushion material.
The following study, comparing the shock test performance between corner- and flat-cushion foam, qualitatively proved that the hidden bearing area does exist in the particular cushion geometry by conducting a dynamic acceleration-level response comparison between these two types of cushion design. It explored the possibility of a new experiment method for quantitatively formulating the hidden bearing area in the future. The shock test result recorded by accelerometers as G's response will provide packaging engineers with solid evidence of hidden bearing area existence, which needs to be considered for improving design accuracy and cost effectiveness by the traditional cushion curve. By conducting the measurement acceleration difference between the two types of cushion design, this study qualitatively proves that the hidden bearing area exists in this particular cushion geometry. This study explores the possibilities of new experiment methods that could be used as a guideline for protective cushioning design in both institute and industry for future use. Whatever the result may be, it will provide packaging engineers with solid evidence of the hidden bearing area's existence and improve both design accuracy and cost effectiveness.
Library of Congress Subject Headings
Cushioning materials--Testing; Packaging--Design
Department, Program, or Center
Packaging Science (CAST)
Li, Chongyue, "The Study of the Hidden Bearing Area: Comparison Between Flat and Corner Cushion Shock Test Performance" (2013). Thesis. Rochester Institute of Technology. Accessed from
RIT – Main Campus
Physical copy available from RIT's Wallace Library at TS198.6.C8 L4 2013