Research On Burning Behavior And Safety Evaluation Of Polyurethane Foam

This paper has introduced the principle and research method of fire performance for building materials, especially for composite materials. Several important performance parameters such as heat release rate (HRR), fire growth rate index (FIGRA) and total heat release (THR) have been analyzed to characterize fire performance of the material. The focus of the present work is to compare the fire classification of foam insulation material by adopting China and the Europe harmonization classification system based on different test methods.One main test method, single burning item (SBI) test, including its test procedure and apparatus is presented definitely in this paper. The potential fire classes for several different foam plastic materials are determined by using the SBI test results. The conclusions of this research work are:1. It is indicated that the foam insulation materials could have different firer classes determined by different sub-classification methods incorporated in GB 8624-1997. The reason is that there are many differences between the oxygen index test method and the hardly flammability test method for foam insulation materials.2. Normally, the oxygen index is one of the parameters mostly used to determine the fire retardant performance of foam materials, but in fact, some foam materials with relatively low oxygen index values behave quite well in the hardly flammability test and SBI test. This is because that there is a relatively small contribution to the real fire, or maybe the contribution is not so much to the fire initiation and development stage as many people expected for such materials. As a result, the small test with the qualitative results such as oxygen index test is not an ideal method for the fire research of foam materials.3. In the SBI test, the fire behavior of the specimen exerts an obvious influence on the HRR and FIGRA at the early stage, which mostly determines the classification result of the foam material. Parts of the specimen are molting and dropping during the exposure period of the SBI test, but the dropping parts are not flaming, such material obtains a better Euro-classification result and could be considered to have a low fire risk. While its China-classification result is not so good.4. Some foam materials can achieve a better classification results by pasting aluminum foil on the foam surface in a proper way to slow down the fire spread rate of...