IMPACT OF PAINTS, VARNISHES AND SMOKE-GENERATION ABILITY AND TOXICITY OF COMBUSTION PRODUCTS OF WOOD

The paper presents the results of experimental evaluation of the impact of various types of foreign and domestic wood paints and varnishes on smoke-generation ability and toxicity of combustion products. Investigated coating systems are used in practice for both external and internal finishing materials and designs based on wood. The study found that chemical nature of varnishes and paints, thickness of protection layer and the use of multilayer coatings combinations have the significant effect on smoke generation and release of toxic combustion products. The tests were conducted in the flameless mode smoldering for wood burning without an additional source of ignition. Based on the results evaluation it was found, that paints can both increase and decrease smoke-generation ability and toxicity of combustion products of natural wood. The intensity of smoke generation and output of toxic combustion products are largely determined by the nature and characteristics of pyrolysis or thermal decomposition of wood material in the presence of varnish or paint. A very interesting result is obtained by reduction of the wood smoke generation when using certain types of paints, with relatively high values relative viscosity that forming on the wood surface by visual inspection thin film layer. The obtained results allow to choose the most effective approaches and solutions to reduce the fire hazard of wooden structures with varnishes and paints, as well as to ensure their fire safe usage with timber construction.