Analysis and Modeling of Ignitability of Polymers in the UL-94 Vertical Burning Test Condition

ABSTRACT: Modeling the UL-94 vertical burning test is of practical importance in industries which, however, has not been addressed sufficiently. In this article, a 3D convective heat transfer model was developed to simulate ignition times for the UL-94 test. An experimental procedure was proposed to measure ignition times of two polymers under the UL-94 test condition. Comparisons between experimental and simulated results of ignition times showed that edge effects were significant in the ignition process of the UL-94 test and the convective heat transfer ignition model considering edge effects gave ignition times close to experimental results. Sensitivity analyses showed that the ignition time increased linearly with decreasing initial temperature and increasing density, heat capacity and emissivity, but nonlinearly with decreasing flame temperature and convective heat transfer coefficient and increasing thickness, thermal conductivity, and ignition temperature of the specimen