Behavior of Plywood Lining in Full Scale Room Fire Tests

A detailed study of the behavior of plywood wall lining was conducted in an ISO room enclosure fire. In addition to its contribution to fire growth, observations included ignition behavior, surface flame spread, and charring of the lining. For the corner fire scenario conducted in this study the linings responded differently in three distinctly different regions of each of adjacent walls, i.e., region I close to the fire source; region II at the ceiling and wall interface; and region III the remainder of the wall surface. In region I, ignition occurred over a relatively large area, resulting in a large pyrolysis front and rapid upward flame spread. In region II, convective heat flow preheated the lining surfaces but ignition was induced by a laterally advancing flame front. Region III was characterized by downward flame spread from region II while lateral flame spread from region I to region III was negligible. Ignition in region III was caused by the downward advancing flame front and a distinct linear pyrolysis front was apparent. The rate of flame spread increased with room temperatures. The data obtained suggest that the developed fire in regions I and II was not sufficient to cause flashover. When fire spread to region III, flashover rapidly ensued. The analysis of charring of the linings indicated two areas of severe burning, one directly in line with the source fire plume and the other at the boundary area between the ceiling and the wall, close to the fire corner location. Language: en