Study On The FRW-1 Fire-retandant Poplar Plywood

Wood fire-retardant FRW-1 solution at concentration of 10%was used to impregnating Poplar veneer at thickness of 2mm.The normal pressure impregnating process which was impregnating 2 hours under room temperature(25℃) was defined by single factor test,and by this technology,the Poplar veneer could got 8-10%chemical loading.The SEM-EDAX results showed that fire retardant distributed around wood vessel wall and pit presenting aggregation state and dispersed state in homogeneously.The treated Poplar veneers with the 8～10%chemical loading were pressed into 3-layer plywood which formed as the same assemble pattern with different ranges of veneer chemical loading or the different assemble patterns with same range of veneer chemical loading,and then the heat release parameters were obtained under a heat flux of 50 kW/m~2 by cone calorimeter(CONE).The heat release ratio peak(pk-HRR) and total heat release(THR) results showed as follows:the pk-HRR could maintain at 120～140 kW/m~2 in which level can satisfy the fire retardation requirement at normal situation.However,the fire retardation property was different as the different assemble patterns.The assemble pattern with the untreated Poplar veneer as the middle layer in the 3-layer plywood(we call this kind plywood as interstratified fire retardant plywood,IFRP for short.) could meet the demand of general fire retardancy which had the same chemical loading range.The pk-HRR,THR,smoke release ratio peak(pk-RSR) and total smoke release(TSR) of IFRP were remarkably decreased,and the carbon residue ratio was increased.The IFRP appeared to be very good fire retardation and smoke suppression properties.Fire-retardant plywood was gained through the normal manufacturing technique.The results of bonding strength and formaldehyde emission showed that the bond strength and formaldehyde emission of FRW-1 fire-retardant plywood were lower than the untreated plywood.The influencing factors on adhesive bonding of fire-retardant treating on the wood acid alkali properties and the curing of adhesive were discussed in this paper.