Preparation And Properties Of Konjac Glucomannan Cushioning Package Material

With the development of the society, the distribution of various products become more frequently in our lives, and cushion packaging plays an important role during transportation. At present, the most widely used cushion packaging material is expanded polystyrene, however expanded polystyrene is difficult to degrade. Therefore, it is meaningful to develop a biodegradable cushioning package material that took natural material as raw material, so as to replace the current widely used low-density foamed polystyrene. Konjac glucomannan(KGM) is the main component of Konjac, which is a kind of renewable natural polymer resources. Konjac glucomannan also can prepare the cushion material, because its aqueous solution has gelling property.This paper mainly introduced a novel biodegradable cushioning package material, which took Konjac glucomannan(KGM) as raw material and prepared by the freeze-drying method, its properties were also investigated. The changes of density, porosity, aperture, static compressive property and compression-resilience property due to the variations of KGM concentration, freezing temperature and freezing time influencing were also analyzed. According to the microstructure of cushioning material, the component model was established. Finite element software of ABAQUS was use to simulate the process of static compression. The simulation results were consistence with the experimental results, which can verify the validity and rationality of numerical simulation. Using simulation results as a substitute for experimental results will shorten the cycle of the experiment and save the cost of research. The major contributions and findings are summarized as follows:(1)With the increase of the KGM concentration, the porosity of cushioning package material decreased, but the aperture, elasticity modulus and yield strength of cushioning package material were increased. The stage of densification earlier appeared.(2)With the fall of freezing temperature, both the aperture and porosity of cushioning package material decreased, but the elasticity modulus and yield strength increased. The stage of densification earlier appeared, and compression resilience ratio increased. With the extension of freezing time, the porosity and aperture increased. But the elasticity modulus and yield strength decreased, compression resilience ratio also decreased(3)When the KGM concentration was 3%, freezing last for 12 h at the temperature of-20°C, Got the minimum cushioning coefficient of 2.79 and the maximum static stress of 0.15 Mpa. The compression performance of KGM cushioning package material at the concentration of 3% was similar to the low density expandable polystyrene, which has the further application potential.(4)The simulate compression process by finite element was consistence with the actual situation, simulation results was similar to experimental results. The whole compression process includes three stages: elastic stage, yield stage and densification stage. With the decrease of the porosity, the elasticity modulus and yield strength increased, the stage of densification earlier appeared. The stage of densification also bring forward. With the increase of aperture, elasticity modulus and yield strength decreased, the stage of densification even later appeared.