Effects of temperature and thickness of wood based boards on formaldehyde emission

This study investigated the effects of board thicknesses and temperature on formaldehyde emission (FE) for different wood based boards, sampled from standard particleboard (PB) and medium density fiberboard (MDF). Test samples with the thicknesses of 8, 12, and 18 mm analyzed for formaldehyde emission at temperatures of 10, 20, 25, and 30°C and 65% relative moisture conent for 60, 120, and 180 minutes after production. The highest value of FE was found at 1.2922 ppm for PB and 0.3800 ppm for MDF of 18 mm, treated at the temperature of 30°C. The lowest emission was found to be 0.0611 ppm in the PB of 8 mm, and 0.0444 ppm for 18 mm MDF, treated at a temperature of 10°C. A significant increase for FE was detected in all board types at the temperatures of 20, 25, and 30°C. However, a significant decrease was also detected at 10°C for all types of boards. Accordingly, an increase from 101% to 1,192% and a decrease from 39% to 9% was observed for PBs. MDF samples yielded better results as an increase from 4% to 280% and a decrease from 55% to 31%. Regarding distance to E1 (0.10 ppm), all values were above the limits of E1 (≤ 0.10 ppm, EN 717-1), except samples treated at 10°C. In conclusion, the temperature and thickness of wood based boards significantly affect their formaldehyde emissions.

Eco-design: Impacts of bleaching chemicals and varnishes on the amount of carbon dioxide in the combustion of oriental beech (Fagus orientalis Lipsky)

This study was carried out to determine the effects of bleaching chemicals and varnishes on the amount of carbon dioxide (CO2) in the combustion of oriental beech (Fagus orientalis Lipsky). For this purpose, samples of Oriental beech prepared according to ASTM D 358 contain 18% R1 = (NaOH + H2O2), R2 = (NaOH + Ca(OH)2 + H2O2), R3 = (Na2S2O5 + H2C2O4), R4 = (NaSiO3 + H2O2), R5 = (KMnO4 + Na2S2O5 + H2O2) solution groups, after bleaching with solution groups, water based, synthetic, polyurethane and acrylic varnish were applied according to ASTM D 3023 and combustion tests were carried out in accordance with ASTM E 160-50. Gas measurements were made with the SIGMA 74172 NSU flue gas device during the combustion process. As a result, in respect to the burning types; the highest amount of CO2 (ppm) was found in the self-combustion (8.468 ppm) while the lowest was obtained from the flame combustion source (4.599 ppm). In respect to the types of bleaching; the highest in R5 (7.458 ppm) and the lowest in R3 (4.059 ppm) were found. According to the varnish types; the highest value was found in the synthetic varnish (8.261), and the lowest value was found in the acrylic varnish (4.772 ppm). According to combustion type + bleaching solution + varnish type interaction, the highest values were found for without flame combustion (II) + R3 + Sn (18.40 ppm) and lowest for flame source combustion (I) + R5 + Pu (0.600 ppm). Consequently, the highest values for combustion gases were found in samples of oriental beech wood samples treated with water-based varnish with R1 solution. According to this, in terms of human health and life safety, possibility of fire in places, R3 solution and acrylic varnish may be used in the related industries.