Effects of Particle Size of Fumed Silica and Aluminium Trihydrate on Fire Performance of Intumescent Fire Retardant Coating

Intumescent coating is a form of passive fire protection where paint is coated on the metal and later reacts chemically in fire. The coating expands to greater size forming char that protects the steelwork for a specified time period from the heat of fire thus elongate the time for the occupants to escape. In order to produce an efficient intumescent system, three ingredients are required; an inorganic acid, a carbon rich polyhydric material as char former (carbonific) and a blowing agent called a spufimic. Aluminium trihydrate and fumed silica are two fillers used widely in intumescent coatings composition and is proven to be efficient in thermal insulation and durability of char under excessive fire. Different types of formulations are prepared for the intumescent coating and each formulation is altered in the mixture of fumed silica and ATH under different particles sizes.
The particle size of both fumed silica and ATH are altered by grounding it into smaller sizes. The variation of surface area of both fumed silica and ATH will directly affect their performances in technical applications such as thickening efficiency, reaction with heat and the expansion rate of the intumescent coating.
The effects of the particle size of the fillers on fire performance and char expansion rate has been studied. The results obtained from the fire testing will be compared and analyzed in order to identify the best mixture for intumescent coating. Then 4 best samples which provided maximum char expansion will be chosen. Those samples will be analyzed using TGA and XRD to study its residual weight and composition of how percentage of fillers has on intumescent coating. Overall this study identified the best mixture of formulation of intumescent coating with high flame retardant characteristics towards heat/fire.