Experiment And Numerical Simulation On Thermal Insulating Property Of Vermiculite Materials

The insulation of the vermiculite used in the thermal insulating materials can improve the thermal protective performance of materials. The general method used to assess the thermal protective performance of fabric is the TPP experiment. At present, the development of new protective materials, rely mainly on a large number of thermal protective performance tests. It can assess the thermal protective performance of fabric, but the cost of developing new materials will increase. In this paper, the new insulating material which contained vermiculite was prepared by L-S phase inversion method. One-dimensional heat transfer model of fabric was established. Then the ANSYS software was used to simulate the thermal protection properties and forecast the influence of the different factors.Firstly, the new insulating material which contained different content of vermiculite was prepared by L-S phase inversion method, with water / DMAC (ratio 1:1) as the coagulation bath, through the casting liquid preparation, coating, replacement and drying. The performance parameters such as the thermal heat capacity, thermal conductivity coefficient were measured. It showed that vermiculite can improve the insulation properties of materials, but there is a limit amount of its content, about 10%.when the amount is lower, the thermal properties such as heat capacity, thermal conductivity coefficient were better with the more vermiculite content; In the opposite, when the amount is higher, the changes of the thermal properties become irregular.Secondly, materials were tested by TPP experiment. It showed that vermiculite content had impact on the thermal protective performance of materials. It also had a limit amount of its content, about 10%. When the amount is lower, the time of the second degree burn injury was increasing with the more vermiculite content. However, when the amount is higher, the amount was negative for the time of the second degree burn injury.Thirdly, a one-dimensional fabric heat transfer model was established. Then the ANSYS software was used to simulate the thermal protection properties. And the model was validated by the thermal protective performance of the composite material with vermiculite. It showed that the relative error between the numerical simulation and experimental results was less than 5%.Finally, in this paper, the model was used to forecast the thermal properties of materials. Factors such as the coating thickness, the type of intercalated vermiculite, vermiculite content, the type of substrate and the coating methods were discussed. The results showed that with the thickness increasing, the time of the second degree burn injury was increasing. The thickness and the thermal insulating materials had a positive correlation; Single-sided coating or double-sided coating did not impact on the insulation properties of materials. In addition, three type of intercalated vermiculites were discussed. It was found that the type of intercalated vermiculites had an impact on the time of the second degree of burn injury. The time of the second degree of burn injury of the material with C₁₆TA⁺ intercalated vermiculites was the longest, while the others had little difference. The type of substrate also had an impact on the insulation properties of materials. The relatively better insulation properties of substrate can significantly improve the insulation properties of materials.