Investigation on attrition strength of coated particles by response surface methodology

The purpose of the present study is to obtain better understanding of the influence of different variables on the strength of coating, applied onto sodiumbenzoate particles. Through fluid bed coating of 1 mm sized particles, three experimental factors have been studied: the coating quantity related to the particle weight, the glasstransition temperature (Tg), and the fluid bed temperature (TFB). Through repeated impact, the resistance to attrition of the coated particles was tested, which is a measure of the strength of the coating. The experiments have been designed according to the response surface methodology (RSM). From statistical analysis, the coating quantity appears to have a significant effect on the resistance to attrition of the coated particle. This relationship is linear and positive, which means that an increasing quantity leads to more resistance to attrition. No direct effect on coating strength is detected of the fluid bed temperature.