Graphite carbon rods are divided into two types: natural and artificial. It is a crystalline carbon with metallic luster. According to the carbon content, graphite rods are divided into high carbon graphite rods, medium carbon graphite rods and low carbon graphite rods.
Graphite carbon rods are widely used in battery technology electrodes, metallurgical refractory materials, chemical lubrication and sealing materials and other fields. As functional fillers of coatings, they are mainly used in fire-resistant coatings, anti-corrosion coatings and conductive coatings. Moreover, as a kind of anti-corrosion material, the graphite rod is added with chemical pigments such as zinc yellow in the formula, and the anti-corrosion effect is better.
Expanded graphite rod as a flame retardant filler is a chemically or electrochemically treated graphite rod sandwich compound.
The expandable graphite rod expands rapidly under heating conditions, suffocating the flame, and at the same time producing an expanding substance that isolates, delays or interrupts the flame propagation, is non-flammable, non-soft and has good flexibility, surface energy and carbonization layer strength, etc.
Moreover, the volume and quantity of the expansion body should be selected correctly. Experiments show that 150 micron particles, 30% expansion ratio and 5% dosage are very suitable.
Therefore, graphite carbon rods can be directly used as carbon conductive fillers, and graphite rods can also be made into composite conductive fillers for conductive coatings.
However, due to the existence of a large number of graphite rod flakes, the performance of the coating will become brittle, which limits the application of the coating to a certain extent.
At present, carbon graphite rod is a new product, which is made of high-purity, high-strength and high-density graphite. It has the advantages of good chemical stability, energy saving and environmental protection, acid, alkali and organic solvent corrosion resistance. What should I pay attention to when using graphite rods?
1. Red heat uniformity
In the process of use, the red heat uniformity of the graphite rod will gradually decrease, and fracture will occur in severe cases. Therefore, it is necessary to select a graphite carbon rod with good red heat uniformity as the heating component.
2. The temperature is too high
With the increase of temperature, the oxidation time became shorter, and the oxidation rate increased with the increase of temperature. For example: when the temperature exceeds 1500 ° C, the oxidation rate is accelerated and the life is shortened. Therefore, care needs to be taken to control the surface temperature of the graphite rod.
3. Silicon oxide film
When it is heated in air, it forms a film (a dense film of anti-oxidation silicon) that prolongs its life. However, if it is not used continuously, as the temperature rises and falls, the curing film on the surface of the steel bar will rupture, thereby weakening the curing effect and accelerating the increase in the resistance of the steel bar.
According to the different voltage regulation and wiring methods, the upper limit of the later voltage is generally calculated as 220V or 380V. Voltage residual value: The voltage of the graphite rod in the later period of use is generally 1.5-1.7 times that of the new rod.
The power of the graphite rod can be adjusted by adjusting the voltage. Generally, there is no need to tune the power modulator by changing the frequency of the wavenumber.