Limitation of smoke emission properties of plastics

Basic information on methods of smoke properties measurement, according to Polish Standards obligatory for railway stock, were presented. Determinations of the values of illumination (E) and exposure (S) were done, as in the Standard, to characterize on this basis the smoke properties of high impact polystyrene (PS-HI) flame retarded with various amounts (up to 50 wt. %) of halogen free flame retardant - Mg(OH)2 (Table 2, Figs. 2 and 3). It has been found that PS-HI containing 40-50 wt. % of Mg(OH)2 reaches DL class (material of medium smoke properties) and can be used to produce nearly all elements of rolling stock equipment. The change in smoke color from black to gray or white, caused by Mg(OH)2 is also substantial.