Impacts of the bleaching and varnishing process on the collapse time in combustion of oriental beech and scots pine woods

Abstract

This study aims to determine the effects of the bleaching and varnishing process on the collapse time in combustion of some wood materials. For this purpose, samples prepared from wood of Oriental beech (Fagus orientalis Lipsky) and Scoth pine (Pinus sylvestris Lipsky) according to ASTM D 358, were covered with waterbased (Sb), synthetic (Sn), polyurethane (Pu) and acrylic (Av) varnishes in accordance with ASTM D 3023 after bleaching with 18 % solution of sodium hydroxide (NaOH), hydrogen peroxide (H2O2), calcium hydroxide (Ca(OH)2) and sodium silicate (NaSiO3). The collapse time on combustion of repared samples were determined according to ASTM E 160-50. According to the result of reseach, collapse time according to interaction of wood types was gained the highest time Oriental beech (877.6 sn), the lowest time Scotch pine (570 sn), according to varnish types was gained the highest time polyurethane (776.7 sn), the lowest time waterbased (563.1 sn), according to bleacher types was gained the highest time R5 (800.3 sn), the lowest time R2 (645 sn). According to the interaction of wood type, varnish type and decolouring solution, longest collapse time was obtained in I+R4+Sb (1260 sec) and the shortest in the combination of I+R3+St (630 sec). Accordingly, in places where there is a risk of fire, Oriental beech wood R4 bleaching solution + water based varnish combination can be recommended.

Keywords

• bleaching
• varnishing
• collapse time
• wood material
• renk açma
• vernikleme
• yıkılma süresi
• ağaç malzeme