The present study is involved in investigating the flammability behavior of polyurethane foam cored E-glass reinforced vinylester sandwich composites. As fire is a major safety hazard for civil, commercial and transport systems, the objective of the work is to establish a complete assessment of properties pertaining to the heating and burning characteristics of these materials under fire. An attempt has been made to find the behavior of the wide range of sandwich specimens with varying core density and fibre architecture through its decomposition while at their burn. The composites burn primarily from the combustion of its resin material and burns in a manner similar to a charring material. The procedure involved in the test is to ignite the specimen with a pilot flame in horizontal and vertical positions. It is observed that, the burnt resin is forced out of the fiber pores, and burn pressure causes the material to swell over its original volume. Cracks are formed on the surface of core material and low density foam cores are found to be bending while burning. As the burning rate drops, extinction naturally occurs due to insufficient heating which is due to degasification of core.
