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Methods of calculating the physical acation of flame retardants
Author(s) -
Sellman L.G.,
Östaman B. A.L.,
Back E. L.
Publication year - 1976
Publication title -
fire and materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.482
H-Index - 58
eISSN - 1099-1018
pISSN - 0308-0501
DOI - 10.1002/fam.810010302
Subject(s) - fire retardant , boric acid , inert , flame test , materials science , ignition system , absorption (acoustics) , inert gas , physical property , composite material , chemistry , organic chemistry , thermodynamics , physics
The chemical mechanisms for the action of flame retardants are often mentioned in the literature but the physical modes of action are seldom. Discussed. This article presents one way to quantify their efficiency. The technique is based on literature data for the physical and thermal properties of flams retardants for temperatures from 25°C up to 1000°C. The prolongation of the time to ignition by heat absorption by the retardant and the amount of inert gas evolved by the retardant are calculated at a given radiation for a material flame‐proofed with a given amount of the flame retardant. The ability to form an insulating surface layer is considered but not quantified. It is assumed that a medium density wood fibre building boards is treated with 2 kg of flame retardant per m 2 . The flame retardants included are borates, boric acid, phosphates and silicates. The board is assumed to be irradiated with an intensity of 15 k W m −2 . Under these conditions an untreated board ignites after 6–7 min. The time to ignition is prolonged by 1–5 min through heat absorption by the different retardants, and the amount of inert gases evolved may be as high as 2.6 m 3 per m 2 board. The formation of an insulating surface layer is more difficult to quantify. The results confirm the importance of the physical modes of action of flame retardants and the technique could form the basis for evaluating materials in simulated fire situations.