Why Expandable Graphite is suitable for insulation and flame retardant materials
In various fields of industry, often choose to expand the graphite as a thermal insulation materials for processing production. What are the characteristics and advantages of Expandable Graphite to make it a hot choice for the first choice of materials, Expandable Graphite is through what process to achieve the purpose of thermal insulation flame it, today we talk about why graphite edible graphite is separated The best choice for thermal flame retardant materials:
Expandable Graphite is a natural flake graphite that has been chemically treated from scaly to loose, porous worm-like graphite. In industrial production, Expandable Graphite forms a tough carbon layer on the surface of the polymer, separating the combustible from the heat source; absorbing heat in the process of expansion, reducing the temperature of the system; releasing the acid in the interlayer during the expansion Ions, promote dehydration carbonation, and can combine the free radicals generated by combustion to interrupt the chain reaction. Expandable Graphite and phosphorus compounds, metal oxides can produce a synergistic effect, adding a small amount can achieve the purpose of flame retardant.
Expandable Graphite for thermal insulation has a huge advantage:
First, Expandable Graphite produces less smoke and has a significant effect.
In general, in order to make the object has a flame retardant function, will add halogen-containing flame retardant, but will produce smoke and acid gases, which will affect people's health will also corrode indoor equipment; will add metal hydroxide, but Will have a great impact on the impact resistance and mechanical strength of plastic or substrate; it will add phosphorus flame retardant, but in the case of air is not very smooth will have a serious impact on people. Expandable Graphite is even more ideal. Will produce very little smoke and the flame retardant effect is remarkable.
Second, Expandable Graphite can improve the processing temperature of flame retardant materials.
In industrial production, people commonly used method is to add flame retardant in engineering plastics, but because of the low decomposition temperature, will lead to decomposition will eventually lead to failure. The physical properties of the Expandable Graphite are stable and does not affect the quality of the processed material, resulting in improved flame retardancy.
Third, the expansion of graphite has a good insulation, anti-corrosion properties.
Expandable Graphite is a corrosion-resistant material that exists in a stable crystalline form. Not because of limited shelf life and stability, in the decomposition, oxidation in the deterioration until failure.
Expandable Graphite is a good performance of the adsorbent, in particular, it has a loose porous structure, organic compounds with a strong adsorption capacity, 1 g of Expandable Graphite can absorb 80 g of oil, so that the expansion of graphite was designed to various Industrial grease and industrial oil adsorbents. Expandable Graphite is very easy to adsorb oil, organic molecules and hydrophobic substances for water environmental treatment with other substances irreplaceable effect. When it is used in granular form for surface oil removal, depending on the size of the oil on the surface and the type of oil, the amount is 1 ~ lo% / rn, the adsorption time can be from 15rain to several h.
Compared with other adsorbents, Expandable Graphite has many advantages. Such as cotton, grass ash, polypropylene fiber, perlite, vermiculite, etc., which are used in the presence of some of the adsorbents, such as cotton, grass ash, polypropylene fiber, vermiculite, and so on. The oil can be absorbed at the same time, it is difficult to deal with the post-processing; Expandable Graphite adsorption of oil, after the oil floating in the water, easy to capture, recycling easy to use, can be used extrusion, centrifugal separation, Solvent cleaning, combustion, heating extraction and other methods, and will not form secondary pollution.
In modern industry, the amount of Expandable Graphite is very large. In addition to being used as a flame retardant material in many industries, Expandable Graphite is also used as an adsorbent to absorb different oils or moisture due to its loose porous structure.