Expandable graphite for the fire protection industry
In the past few years, a wide variety of expandable graphite has been developed, suitable for many applications. One of these applications is the fire protection industry, a subject that is becoming more and more important.
Expandable graphite is used as an environmentally compatible flame retardant and fire protection additive free of halogen. It is a natural graphite with a multi-layered structure to which salts are introduced by chemical process. As heat is generated, the salts cause a large and rapid increase in volume, also called “expansion”. Graphite expands up to 600 times depending on the grade. The resulting volume allows for rapid oxidation of the carbon leading to the elimination of oxygen from the surrounding air and the air becomes inert; the fire is smothered.
Expandable graphite is also used in the metallurgical, lubricant, chemical and electrical industries.
Expandable graphite – Applications
Expandable graphite is mainly used in fire protection applications, including :
- In partitioning pipes and cables
- Between fire walls and ventilation systems
- Door and window seals: Expandable graphite protects them in the event of fire and limits the spread of fire
- Lacquers and paints: expandable graphite provides fire protection
- Textiles: fire protection additive
- Carpets back in aircrafts or trains
But also :
- Metal industry: used in covering powders to keep the heat/energy
- Chemical industry
- Lubrication industry
- Electrical industry
There are many different types of expandable graphite, for all types of applications. The larger the graphite particles, the greater the expansion volume of the graphite. The finer the graphite particles, the smaller the expansion volume of the graphite.
Expandable graphite – Fire protection properties
Due to its outstanding properties, expandable graphite is mainly used for fire protection.
- On contact with heat, expandable graphite expands up to 600 times its original volume, which leads to rapid oxidation of the carbon, the air becomes inert, and the fire is smothered.
- Expandable graphite does not form a flame and is extinguished when heat is reduced, so it does not cause a fire.
- Used around windows, doors, ventilation systems, graphite will form a barrier that will prevent air supply and fire spread.
Of the many grades of expandable graphite, the most common are:
Expandable graphite with normal start temperature and high expansion | |||
Carbon content | Start temperature | Expansion | Particle distribution |
>95 % | Approx. 200°C | >200 cm³/g | 80% > 250 µm |
>98 % | Approx. 180°C | >400 cm³/g | 80% > 300 µm |
Expandable graphite with low / high start temperature | |||
Carbon content | Start temperature | Expansion | Particle distribution |
>98 % | Approx. 140-160°C | >200 cm³/g | 70 % > 300 µm |
>95 % | Approx. 230°C | >100 cm³/g | 70 % > 300 µm |
Expandable graphite with fine particle size | |||
Carbon content | Start temperature | Expansion | Particle distribution |
>95 % | Approx. 200°C | >40 cm³/g | 80 % < 75 µm |
In addition to the standard grades listed, COMAP SAS can provide other grades to meet customer applications. If you need an expandable graphite not mentioned below, our team will be pleased to help you.
COMAP SAS has been specializing in the import-export of graphite materials for over 40 years. We work closely with producers who respect ethical and quality standards. If you are looking for a reliable supplier of expandable graphite, contact us.