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pinfa's first workshop in China confirms interest in halogen free FRs
In June 2016, over 250 people from academia, indus
1st International Asia-Oceania Symposium on Fire Safety Materials Science and Engineering (AOFSM’1 2015)
The 1st International Asia-Oceania Symposium on Fi
European fire tests for cables in building and CE-marking
In 2008, in the context of the Construction Produc
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In a U.S. statistical overview from NFPA[i] on ele
prEN 16733: Standard draft for testing and classifying the propensity of construction products to undergo continuous smouldering
In the past, the smouldering of construction produ
15th Conference on „Fire Retardancy and Protection of Materials, FRPM 2015”
The 15th Conference on „Fire Retardancy and

Intumescent flame retardant systems

Mode of action: formation of a voluminous, insulating protective layer through carbonization and simultaneous foaming

Intumescent systems puff up to produce foams. They are used to protect combustible materials such as plastics or wood, and those like steel, which lose their strength when exposed to high temperatures, against the attack of heat and fire.

Basically, intumescent flame retardant systems consist of the following:
1. "Carbon" donors (e.g. polyalcohols such as starch, pentaerythritol)
2. Acid donors (e.g. ammonium polyphosphate)
3. Spumific compounds (e.g. melamine)

Process of intumescent mechanism

1. Softening of the binder/polymer (e.g. polypropylene)

2. Release of an inorganic acid (e.g. ammonium polyphosphate)

3. Carbonization (e.g. of polyalcohols)

4. Gas formation by the spumific compound (e.g. melamine)

5. Foaming of the mixture

6. Solidification through cross-linking reactions

The picture below shows how the foam looks in the end. This coating expanded from a 1 mm layer to a 100 mm foam.