Zeolite PIN smoke suppressant for wood
Four different zeolites (aluminium silicate crystals) were tested with the intumescent PIN flame retardant melamine-urea-formaldehyde resin, on 10 mm poplar board. Different zeolites showed varying capacity to suppress smoke emission (probably by absorption of toxic gases into the crystal lattice, depending on pore size and crystal structure flexibility) and to accentuate delay to peak heat release (possibly by degradation of zeolite to silica on and aluminium oxides which improve cross-linking in the char layer).
The authors conclude that low levels of X-type zeolite (1% in resin) can significantly reduce smoke emission and that type A and type X zeolites could be advantageously used together.
“Synergistic flame retardant effects of different zeolites on the intumescent fire retardant coating for wood”, J. Wu et al., Bio-Resources 12(3) 5369-5392, 2017 http://ojs.cnr.ncsu.edu/index.php/BioRes/article/viewFile/BioRes_12_3_5369_Wu_Synergistic_Flame_Retardant_Effects/5357