Research On Cushioning Properties And Application Of Cylindrical Air Cushion

Cylindrical air cushion has been widely used as cushion packaging for products.The lack of research on its cushioning properties leads to the lack of a reasonable cushion packaging design method of the material.Therefore,this thesis studies the cushioning properties of the material and explores the cushion packaging design method suitable for the material.In this thesis,the static compression test,dynamic compression test and sinusoidal sweep vibration test were carried out to study the static cushioning property,dynamic cushioning property and vibration transmissibility of cylindrical air cushion according to the test methods of cushioning properties of packaging materials in the national standards.This thesis also explored the effects of film thickness,initial internal pressure,and air chamber size on its cushioning properties.Besides that,a cushion packaging design method suitable for this material was improved and applied.The main research contents and conclusions are as follows:(1)The cushioning theory of cylindrical air cushion is summarized.The experimental research is carried out on this basis.The effects of film thickness and initial internal pressure on its static cushioning properties are studied by static compression tests.The results show that the effect of film thickness on its static cushioning properties can be ignored.When the film thickness is actually selected,the bearing of the cylindrical air cushion and the strength of the heat-sealed strength should be mainly considered according to the product weight.The effect of initial internal pressure on its static cushioning properties shows a more complex law.When the initial internal pressure increases within a certain range,its static pressure bearing properties improves and total energy absorption increases.When the stress is large,the elastic specific energy will increase and the cushioning coefficient will decrease with the increase of the initial internal pressure.However,excessive initial internal pressure will cause the film to be bulged and deformed easily.(2)The effects of film thickness,initial internal pressure,air chamber size and drop height on its dynamic cushioning properties are studied by dynamic compression tests.The results show that the effect of the film thickness on its dynamic cushioning properties can be ignored.The maximum acceleration decreases and the dynamic cushioning properties improve with the initial internal pressure increases.The maximum acceleration also increases with the drop height increases.When the air chamber size increases,the maximum acceleration decreases and the dynamic cushioning properties improve.(3)A 5.2kg mass block and cylindrical air cushion are selected to form the vibration system,and the effects of cushion thickness and initial internal pressure on its vibration transmissibility are studied by the sinusoidal sweep vibration test.The results show that the system has strong vibration reduction capability at high frequencies.When the frequency exceeds 45 Hz,its vibration transmissibility is less than 1 and close to 0.The damping ratio increases with the cushion thickness increases.The peak value of vibration transmissibility and natural frequency of the system decreases with the cushion thickness increases.The initial internal pressure has little effect on its vibration transmissibility.The transmissibility-frequency curves of three initial internal pressures almost coincide,and the frequency range of vibration isolation is basically the same.(4)A cushion packaging design method suitable for cylindrical air cushion is improved and applied.The method establishes a mathematical relationship between the cushioning coefficient and the strain in the direction of cushion thickness.When it is applied,one of the two design parameters,initial internal pressure or air chamber size,can be selected first to calculate the other.The method is applied to the cushion packaging design of a yogurt maker and the drop tests are carried out.The results show that the new cushion packaging solution meets the requirement of protection.