FLAMMABILITY CHARACTERISTICS OFFINISHED OAK VENEER PLYWOOD

摘要

The Cone Calorimeter was used to evaluate the flammability characteristics of 6,35 mm (1/4in.) and 19.05 mm (3/4-in.) thick oak veneer plywood finished with 0, 3, 6, or 9 coats of either oil-based or water-based polyurethane at incidem beat flexes of 35, 50 and 75 Kw/m2. Three replicate tests were conducted for each combination of variables. Additional tests were conducted in the Cone Calorimeter to determine the minimum heat flux for ignition and to measure surface and back face temperatmure histories. The Cone Calorimeter test results indicate that the type and quantity of polymethane finish have an influence on the flammability characteristics of oak veneer plywood, including the time to ignition, the peak heat release rate and the apparent ignition tomperature. In general, ignition time decrases and peak heat release into increases with increased coating levels forboth the oil-based and water-based pelyurethane finishes. The apparent ignition temperature also tends to decrease with increasing coating thickness. These results indicate that finish treatment can affect the ignition and burning rate of oak veneer plywood surfaces.