Factors Affecting Flame Retardancy by Expanded Graphite
Expanded Graphite is the most commonly used in the industry of fire protection materials, Expanded Graphite fire effect is very significant, and cost-effective, no side effects. In the daily industrial applications, many customers attach great importance to how to match the expansion of graphite in order to achieve the best flame retardant effect, today, Shengda graphite small series for everyone to talk about the impact of expansion of graphite flame retardant factors:
First, the impact of the amount of Expanded Graphite on the flame retardant properties.
When the amount of Expanded Graphite is less than 6%, the effect of Expanded Graphite on the flame retardant effect of the fire retardant coating is obviously increased. However, when the amount of Expanded Graphite is more than 6%, the flame retardant time increases slowly or even increases, so the optimum amount of Expanded Graphite in the fire retardant coating is 6%.
Second, the impact of Expanded Graphite particle size on the flame retardant properties.
The granularity of Expanded Graphite is an important indicator of its basic performance, and its particle size is closely related to its synergistic flame retardancy. The smaller the particle size of the Expanded Graphite, the longer the refractory coating fire resistance, the better the flame retardant performance. This may be due to the fact that the Expanded Graphite, which is smaller in particle size, is more evenly dispersed in the coating system and the expansion is more effective in the case of the same amount of addition; and because the size of the Expanded Graphite is reduced, the oxidant enclosed between the graphite layers Subject to thermal shock more easily separated from the sheet, increasing the expansion rate. Therefore, the small diameter of the Expanded Graphite fire better performance.
Third, the impact of Expanded Graphite curing time on the flame retardant properties.
With the extension of curing time, paint drying time is also extended, the remaining volatile components in the coating to reduce the amount of flammable components in the coating to reduce the flame retardant refractory time. Curing time depends on the nature of the paint itself, and has nothing to do with the nature of the expansion of graphite itself, the actual application of the use of fire retardant coating when the maintenance time is necessary, if the steel brushing fire retardant coating after the lack of adequate time will affect its inherent fire retardant Performance, so that fire performance, resulting in serious consequences.
The above is the expansion of graphite impact of the factors of flame retardancy, Expanded Graphite as a physical expansion of the filler, heated to its initial expansion temperature after the expansion of the expansion and absorb a lot of heat, can significantly reduce the system temperature, significantly improve the fire retardant coating performance. Tian Shengda graphite to remind you that the most appropriate amount of expansion of graphite is 6%; add a small particle size of the expansion of graphite can be more effective to improve the fire performance of the paint, the other should pay attention to paint after brushing the necessary curing time.
In industrial production, Expanded Graphite can be used as a flame retardant, play a role in thermal insulation, but in the addition of graphite, to add Expanded Graphite, so as to achieve the best flame retardant effect. The main reason is the expansion of graphite and Expanded Graphite conversion process, today, Shengda graphite small series for everyone to talk about the expansion of graphite and Expanded Graphite flame retardant process:
To understand the flame-retardant process of Expanded Graphite and Expanded Graphite, we must first understand the difference between Expanded Graphite and Expanded Graphite.
1, the expansion of graphite is already the process of expansion, bulky.
Expanded Graphite and Expanded Graphite are two different products. Expanded Graphite is a product of autofillable graphite after heating at high temperature. Expanded Graphite can be used as a product for cleaning contaminants in water due to its large post-expansion gap and good adsorption function. The
2 Expanded Graphite is not swollen, with the characteristics of rapid expansion of high temperature.
Expanded Graphite after high temperature expansion, can be made of Expanded Graphite, Expanded Graphite by high temperature expansion, the volume increases rapidly, so Expanded Graphite expansion density is generally a few hundred times higher than the natural graphite, the specific surface area is greatly increased , With the increase of the specific surface area of the material, the surface free energy will increase rapidly, so that its surface activity increases, the surface adsorption force increases, so the Expanded Graphite lubricity, gas and liquid permeability decreased, but its chemical properties Or as natural graphite, almost no corrosion of any chemical substances, so that the processing of graphite seals made of good sealing, high temperature, wear resistance, mechanical seal is an indispensable production of raw materials.
Expanded Graphite can reduce the thermal conductivity of the material to achieve the effect of flame retardant, if directly added to the expansion of graphite, the formation of charcoal structure after combustion is certainly not dense. Therefore, in industrial production, to join the Expanded Graphite, it is in the case of heat into the expansion of graphite, can have a good flame retardant effect.