The Research On Buffer Protection Mechanism And Impact Properties Of The Air Cushion

The air cushion is a new cushioning packaging material which the plastic film is divided into a appropriate width of cylindrical chamber, filled with a predetermined air pressure. Due to its light weight, low cost, and good flexibility and impact resistance,the air cushion get more and more applications. Compared with its extensive application, the theoretical research of air cushion is still currently lags behind, most of the air cushion packaging design is still in the experience and imitation design state. Based on the cushioning protective performance of the air cushion as the research object, through theoretical analysis, the falling impact test and simulation analysis, study the influence of falling height, air pressure and chamber width on buffer protection performance of the air cushion, provide theoretical basis for cushion packaging design of air cushion.First of all, through the analysis of the compression deformation of a single air column, get the relationship of compression deformation with the effective bearing area and dynamic volume. Using air thermodynamics theory, established the mechanics model of air cushion in the impact compression process, concluded that the dynamic pressure and stiffness calculation formula which hy the foundations for the cushioning mechanism and test result analysis of air cushionThrough the equation of energy conversion and stiffness characteristics, analyzes the buffer protection mechanism of air cushion under drop impact load. Air cushion makes the package rebound and repeated impact by the elastic potential energy and transmission reflection energy which stored in impact deformation and consumes impact energy, thus it makes a cushioning protective effect on package.Increasing the inflation pressure of air cushion can reduce an impact load which air cushion beared, it improve the cushioning performance of air cushion, but the overlarge inflation pressure can make the number of rebound shock increase and the protective performance of the air cushion is adversely affected.The drop impact test on a package whose weight is7.5kg,the drop height is20cm,45cm,60cm,80cm, verify the correctness of theoretical analysis. From the experimental datas as the peak impact load, maximum stress, the total deformation energy, cushioning coefficient and other parameters,the priority order of the initial inflation pressure of air cushion which can obtain better cushioning performance is respectively80kPa,60kPa,40kPa. Namely:increasing the inflation pressure can reduce the initial impact load of the air cushion and improve the cushioning performance of air cushion. Under the condition above, analysis of the impact of air chamber width on the cushioning performance through the test data.The results show that, in the condition of same drop height and same inflation pressure and the package’s weight is7.5kg, the priority value order of air chamber width to obtain better cushioning performance is50mm,40mm,30mm.ABAQUS software is used to establish simulation model of a liquid crystal display packaging.Through the drop impact simulation analysis, draw a4.5kg package whose drop height is80cm, the inflation pressure scope of air cushion is respectively:A30:50～100kPa;A40:40～90kPa;A50:40～80kPa.In this paper, the research results can provide reference for the packaging design of air cushion and it has theoretical significance and practical value in engineering.