FLAME SPREAD OVER CONSTRUCTION FOAM PLASTIC SURFACES

The article concerns influence of an apparent construction foam plastic density to an oxygen index (OI), oxygen max concentrationÑmax and flame spread speed Vf.s and maximum oxygen concentration at horizontal surface in direction of oxidizer flow (O2 and N2 mix). Here was shown that the speed of flame spread over horizontal surface of radiation-linked foam propylene is evenly increasing with the increase of radiation dose and coming closer to values typical for thermoreactive foam plastics. OI and Ñmax of reactionable oligomer-based foam plastics have weak dependence of their apparent density. As opposed to monolith polymers, difference between Ñmax and OI for such foam plastics does not exceed 2 to 4 points. It is shown here that, with the increase of apparent density of construction foam plastics, the combustion switches into a mode typical for thermally thick fuels. Dependences of oxygen concentration in oxidizer were found which resulted in equation of horizontal surface Vf.s for different kinds of reactionable oligomer-based foam plastics (foam PU, resol foam phenol plastics, carbamide and epoxide foam plastics), ratios for equation were set. The resulted equation can be used for comparative assessment of foam plastics combustibility.