Aluminium Trihydrate, also known as Aluminium Trihydroxide or Alumina Trihydrate, is derived from Bauxite ore. This natural ore is refined to a fine white powder via the Bayer process. After washing and drying it is used as the feedstock for a wide range of Alumina chemicals. The raw material used for the ATH products is from a high purity source.
Flame retardant action
ATH decomposes when exposed to heat yielding aluminium oxide and water by the following reaction:
2Al(OH)3 -> Al2O3 + 3H2O
The decomposition starts at 180°C and is endothermic with a heat change of -1050J/g, a total loss of 34.7% of the original weight is seen. When incorporated into organic materials such as plastics, textiles and wood, the takes heat away from the flame front. Water vapour near the surface of the burning material leads to oxygen depletion reducing the burning rate of the gases.
Smoke suppression action
One reason for using ATH in flame retardant formulations is its action as a smoke suppressant. The high surface area aluminium oxide formed as a result of decomposition absorbs the combustion products responsible for the formation of soot particles.