What is Aluminium paste?
Aluminium paste is mainly used to metallic paints and is manufactured by the wet ball milling method invented by professor Hall in 1935. In this method, the main raw material of commercially pure aluminium (99.0% or greater) is mixed with organic solvents such as mineral spirits and fatty acid lubricants (mainly stearic acid or oleic acid ) in a ball mill, and is milled to assume the shape of a thin, flaky particle.
When used as a pigment in paints, aluminium paste provides the painted surface with good protection and durability. The aluminium flakes shield the painted surface from outside gases, humidity and light rays. The aluminium flakes also add a thermal insulation effects and unique glossy surface. Accordingly, aluminium paste is widely used for silver paint, marine paint, metallic paint for automobiles, printing inks nd as pigments for lasticsExposur to fire/flame and smoking is strictly prohibite3d when handling aluminium paste. Although a dust explosion is ukely, aluminium paste consists of fine aluminium flakes is combination with flammable organicsolvents. therefore it is important to be careful during the handling of aluminium pastes.
Combustion Characteristics of Aluminium Paste
Since the aluminium paste reduces the chance of adust cloud the initial combustion of aluminium pate takes place with the organic solvents. the organic solvent vapoors initially igite, and then at a later stage of solvent combustion the aluminium flake will begin combustion. the combustion is very hot and it appears white in color
Reactivity of Aluminium paste with water, Acid and Alkalis
Contact of aluminium paste with water, acid and alkalis should be avoided because the reaction heat can accumulate and cause a rapid reaction resuling in ignition. When aluminium reacts with water, acid alkali, oxidizing reagents, metal oxides and halides, hydrogen gas is generated. this reaction is exso thermal which generates water vapor.
