Prediction of Properties and Modeling Fire Behavior of Polyethylene Using Cone Calorimeter

Abstract

Fire behavior of pure polyethylene has been investigated by performing thermal analysis using a standard cone calorimeter. Specifications of polyethylene samples were 100 � 1 mm long, 100 � 1 mm wide and 5 mm thick, with mass of 25.0 � 0.1 gm. Sample surface area exposed to the external heat flux was limited to 94 mm in length, 94 mm in width due to use of edge lip sample holder frame. The values of external heat flux used were ranging from 40 - 55 kW/m2 with an incremental step of 5 kW*m-2. Three set of experiments were performed for each value of external heat flux. The results obtained were recorded and fitted to a set of mathematical equations to determine the thermal inertia, critical heat flux and the peak heat release rate. Study shows that thermal inertia value obtained from experimental data was 0.86 kJ2*m-4*K-2*s-1 and from well-known correlations was 0.83 kJ2*m-4*K-2*s-1 with a difference of 3.49 %. The factors to relate the observed critical heat flux with the actual critical heat flux were determined as 0.77 and 0.64. The peak heat release rate for each test was determined using the model equation based on oxygen depletion index and concentrations of gaseous species such as oxygen, carbon monoxide, carbon dioxide and water. The values observed experimentally and the ones calculated had a standard deviation of �4.56 %. Thus, this thesis serves as basis for transformation of qualitative understanding of polyethylene fire behavior into systematic quantification which can be generalized for other polymers and their composites.