The piloted ignition of thermoplastic polymers exposed to transient irradiation is investigated. Previous research measured the radiation emitted through a full-scale, post-flashover compartment fire using Thin- Skin Calorimeters. This data is used in the present study to define the Incident Heat Flux time series to which the samples are exposed. Polymethyl-methacrylate and Polyamide 6 were used. A total of 20 experiments were performed in the Fire Propagation Apparatus. The temperature was recorded at depths of 4, 8, 12 and 16 mm from the surface. A regression analysis is used to estimate the temperature profile at each time step. The Net Heat Flux absorbed by the sample at the surface was calculated using Fourier’s law. Conductive losses through the back face are also calculated. Assessing the evolution of the Net Heat Flux and the conductive losses, we found that under transient irradiation, there is a large uncertainty in the time to ignition of Polyamide samples as the surface phenomena introduces a non-negligible uncertainty which cannot be evaluated in current formulations. It was shown that surface phenomena affect mass transfer considerably, but has a lesser impact on the heat transfer process. An approach to study ignition based on controlling the absorbed energy is proposed for samples in which surface phenomena are significant.

International Seminar on Fire and Explosion Hazards (9; 2019; Saint Petersburg, Russia). Proceedings of the Ninth International Seminar on Fire and Explosion Hazards [Электронный ресурс]: 21-26 April 2019, Saint Petersburg, Russia. Vol. 2 / Peter the Great St. Petersburg Polytechnic University, Autonomous Non-Profit Organization "Fire and Explosion Safety", Gefest Holding Ltd ; [edited by A. Snegirev [et al.]. — Электрон. текстовые дан. (1 файл : 98,7 Мб). — Saint Petersburg, 2019. — Загл. с титул. экрана. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Adobe Acrobat Reader 7.0. — <URL:http://elib.spbstu.ru/dl/2/k19-97.pdf>. — <URL:http://doi.org/10.18720/SPBPU/2/k19-97>.