The graphite tube is accurately installed in the furnace according to the design of the mold protection.Close the lid, start the vacuum mechanical pump exhaust, and start heating up after the real vacuum in the furnace is lower than 1mmHg.Improve the required deposition temperature for about 1 hour, and then pass the following proportion to the nitrogen and propane gas: the induction furnace is 2: 1, and the carbon pipe furnace is 5: 1.The inner and outer surface of the gas can be ensured evenly through the inner and outer surface of the graphite tube.The length of the deposits depends on the thickness requirements of the coating.Throughout the deposition, the mechanical pump has been working. While adding fresh propylene gas, thermal solution gas products are discharged from the furnace through the dust collector.When the required deposition time is achieved, stop the supply of raw materials, cut off the power, turn off the valve of the mechanical pump, and stop exhausting.However, the furnace still keeps negative pressure, and the furnace is naturally cooled.