Expandable Graphite

Expandable Graphite is deriving from natural flake graphite by incorporating acids during production. 

As soon as Expandable Graphite is heated the intercalations form gases which lead to the expansion, multiplying the space between the layers. This effect is mainly used for the flame retardation of different materials to which Expandable Graphite is added. Depending mainly on the particle size, the amount and type of acid the expansion can start between approx. 130°C-230°C. 

Expandable Graphite prevents a flame progression by both plain volume - which has an insulating effect - and by covering a material which blocks the contact with oxygen to some extent. 

The main use is for graphite foils, which are used for heat and chemical insulation, e.g. in gland packings and chemical protection. Further important uses are insulation of cables or bituminous cardboards as well as foamed materials such as special seats and mattresses, which require flame and fire proof properties.