What should be paid attention to when heating and sintering melamine in a tube furnace?
The melamine foam needs to be carbonized at 800 degrees Celsius in a tube furnace through nitrogen protection. I used a porcelain boat, and every time it was fired, it was found that there was little or no sample left. This situation may be oxidized, but each time before setting the temperature, nitrogen should be passed for 20 to 30 minutes, and then the end gas should be passed through. There are also air bubbles in the water, indicating that the sealing should be no problem.
The above phenomenon may be caused by the following conditions:
1. Melamine seems to generate C3N4 at about 500, and the generated C3N4 must be decomposed at 800.
2. It may be that the seal of the porcelain boat is not good. It is recommended to replace the graphite box. It is also possible that the airflow rate is too fast, blowing the powder away.
Melamine has a sublimation at 500-600 degrees. When using a tube furnace for carbonization, a lid should be placed on the porcelain boat (there can be a seam, but it does not need to be too tight), otherwise it will run away with the nitrogen, and it will change again in a place where the temperature is low. into a solid.
The melamine tube furnace developed by Zhengzhou Kejia Electric Furnace can help you solve all problems. If interested, please contact us.