Optimization of conveyer belts fire-resistant rubber properties using a mathematical model of desirability functions

Rubber textile conveyor belts used in underground coal mines require strong and standardized fire-resistant properties in order to guarantee the safety of the work. The Purpose of this work is the optimization of the rubber ingredients which are the main factors that give flammability to conveyor belts. The ingrediends taken into consideration as factors are Sb2O3 (X1), chlorinated parafins (X2) and clay (X3). The experiments were designed using central composite rotatable design (CCRD) of second order, according to the mathematical model of desirability functions. The fitted responses for flammability were Spirit Burner test (Y1), Surface resistance test (Y2), and Limit oxygen index, LOI (Y3). The obtained Optimized Global solution was: X1 = 0.2889; X2 = 0.39 and X3 = -0.832, while composite desirability was 0.932 which is an efficient value for desirability.