Large-scale Experimental Study on Combustion Behavior of Thermoplastics with Different Thickness

Abstract

Mutual-enhancing loop mechanism generally occurs between vertical thermoplastic sheet combustion and the melt induced pool fire. The objective of this study is to investigate the effects of thickness of thermoplastics on their combustion behavior. A corresponding experimental rig is designed based on the ISO 9705 fire test room. Commercially available typical thermoplastics, i.e., polypropylene (PP) and polystyrene (PS) with a thickness of 3 and 5 mm are used in the large-scale experiments. The experimental results show that the thickness of PP and PS sheets plays an important role in increasing the heat release rate and the peak values. The pool fires of a thinner sheet develop faster than those of a thicker one. Relatively smaller peak heat release rate is attained earlier during the experimental tests for a thinner thermoplastic sheet. The peak heat release rate of the 5 mm thick PP sheet is about 9 times that of the PP sheet with a thickness of 3 mm. The peak heat release rate of the 5 mm PS sheet is about 2.5 times that of the 3 mm one. In addition, for PP material, the burning flow induced pool fire area is not as large as that of the corresponding pool area. However, for PS sheets, the melt formed pool fire area is nearly equal to the pool area during the development of pool fires.