The traditional thermal insulation materials are mainly based on increasing the gas-phase porosity and reducing the thermal conductivity and conductivity.
At the bottom of the vehicle, the more obvious is the aluminum plate. Because the exhaust pipe is very hot, it is absolutely impossible without insulation.
In November 2021, China’s alumina output was 5.921 million tons, a decrease of 0.24% year-on-year. The average daily output was 197,400 tons, an increase of 4,900 tons from the 192,500 tons in October 2021.