| Air cushion is replacing some foamed cushioning packaging materials as an environmentally friendly cushioning packaging material in the field of transport packaging.Pillow-shaped air cushion is widely used in the field of transport packaging as a basic form of air cushion in air cushion packaging materials,while the study of air cushion is mostly based on cylindrical air cushion.The research result is based on the large aspect ratio of air cushion,so it lacks universality and representativeness.In this paper,pillow-shaped air cushion is selected as the research object to study the influence of thin film mechanical properties on its cushioning properties.By formulating the research method for the cushioning performance of pillow-shaped air cushion and analyzing the mechanical properties of the film that can affect pillow-shaped air cushion,so as to study the effect of thin film mechanical properties on cushioning properties of pillow-shaped air cushion,and lay the foundation for guiding the development of film materials that can be used for pillow-shaped air cushion.Firstly,three equal quantity model of pillow-shaped air cushion was established according to the cushioning characteristics and structural characteristics,on this basis,geometric compression model and mechanical compression model were established,and the cushioning mechanism of pillow-shaped air cushion was analyzed by its energy conversion model.From the theoretical model of the pillow air cushion,it can be known that when the film material is constant,the load of the air cushion when subjected to external force during static and dynamic compression depends on the specifications of the air cushion,the initial inflation pressure,the amount of compression deformation and other factors.Secondly,a research system for cushioning properties for pillow-shaped air cushion was formulated,that is,from static test research to dynamic theoretical research to dynamic test verification.The research results showed that the initial inflation pressure and air cushion specifications of pillow-shaped air cushion have a significant effect on cushioning properties of the air cushion;in a certain range,the lower the initial inflation pressure,the better the static cushioning properties of the air cushion and the worse the dynamic cushioning properties;the smaller the size of the air cushion and the larger the aspect ratio,the better the static cushioning properties of the air cushion and the worse the dynamic cushioning properties of the air cushion,and among these two factors,the aspect ratio has a more significant impact.At the same time,the feasibility of the three equal quantity model of pillow-shaped air cushion was verified.Thirdly,the tensile strength and puncture strength were determined as the mechanical properties of the film material which affect the cushioning properties of pillow-shaped air cushion.Then,the extreme analysis of other factors besides the mechanical properties of the film was carried out through the orthogonal test,and the primary and secondary order of these factors affecting the cushioning properties of the air cushion is air cushion specification,initial inflation pressure,temperature,and compression rate,and the optimal scheme was selected to determine the control variables in the experimental study on the influence of the mechanical properties of the thin film on the cushioning properties of the pillow-shaped air cushion.Finally,the influence of the mechanical properties of the film on the cushioning properties was studied through the established cushioning properties research system of pillow-shaped air cushion,and the empirical equation of static and dynamic cushioning properties can be used to guide the development and selection of thin film materials were obtained.In the static compression process,the mechanical properties of the film had little effect on its bearing capacity when the air cushion was in the initial stage of compression,and the effect was significant when the compressive load was large.At this time,as the mechanical properties of the film increased,the static cushioning properties of the air cushion was increased,and the main evaluation index was the yield point stress of the film material.During the dynamic compression process,the mechanical properties of the film had a significant impact on its cushioning properties,as the mechanical properties of the film increased,the dynamic cushioning performance of the air cushion was increased,and the main evaluation index was the maximum force stress of the film material. |
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