If you are in the field of bulding design, specification or installation and need to be better informed on Fire Engineering, Dougal Drysdale (world famous in this area) has published a book - An Introduction to Fire Dynamics
An intumescent material is one that undergoes a chemical change when exposed to heat or flames, becoming viscous then forming expanding bubbles that harden into a dense, heat insulating multi-cellular char.
The objectives of intumescent technology are the containment of fire and toxic gases by inhibiting flame penetration, heat transfer and transport of toxic gases from the site of a fire to other parts of a structure.
A typical, practical application of intumescence is in fire seal technology, where stips of intumescent material in a carrier are fitted around the perimeter of a fire door. During a fire the fire seals intumescence (expand and char) to resist fire penetration and prevent the spread of fumes.
Intumescent technologies are widely used in passive fire protection systems, where potential pathways for the spread of flames and fumes, such as conduits, wall openings and ventilation grilles are fitted with fire retardant products. Passive fire protection materials are usually combined with "active" fire supression technologies such as sprinklers, foam generation and inert gas systems.
Our products are based on the chemistry of expandable graphites which have the following advantages
Used as a basic flame retardant, the crucial feature of expandable graphite is its intumescent property - both in free expansion and expansion under pressure. But for a fire retardant foam, for example, properties other than basic intumescent are important namely, neutral pH value, low initial viscosity, high SET and small particle size. In other fire retarding applications the expanded carbon layers would lack stability unless combined with (halogen-free) flame retardant additives, such as APP, ZB, NP28 etc.
An optimum grade of expandable graphite, depending on final application, is used in our products.
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