Analysis Of Cushioning Property Of Foam-in-place Material And Optimum Design Of Packaging Structure

In this paper, foam-in-place material is used for cushioning packaging, and dynamic theory of cushioning packaging is applied to optimum design of cushioning packaging. The cushioning action of protection to product is researched with the dropping process of foam-in-place package, which is aslo simulated by means of finite element method (FEM).In the first section of this paper, the advantage and forming method of the foam-in-place packaging are introduced. Then cushioning property of this material is researched by means of compression test, mechanical analysis and microstructure-based simulation. The results show that the foam-in-place material has a good cushioning capability, and its internal stress and energy absorbed increase correspondingly with the increase of the filled percent of foamed liquid (PFL for short). The material with bigger PFL value can afford the bigger load.Based on the theory of cushioning packaging, optimization equation of cushioning packaging design is worked out. In order to design cushioning packaging for various products, an optimum design system is developed by Delphi in this paper.To investigate the influence of foam-in-place material with different PFL values on the cushioning efficiency while dropping, the dropping test simulation has been conducted. The results show that the maximum acceleration and the internal stress of the product decrease with the increase of PFL value.To verify the optimum design system, a cushioning packaging is designed for protecting a vitreous-china sanitary ware, and dropping processes in every diretction are simulated by FEM. The impact and the maximum acceleration of product during surface dropping are the biggest. Kinetic energy generated during dropping is almost absorbed by the cushion, which can protect the product effectively. The maximum acceleration values of the product in different dropping direction are lower than its brittle value.Physical drop test to the package of water tank confirmes the validity of the foam-in-place packaging, the FEM simulation on dropp test is effective also.