The Study On Fire Performance Of Typical Thermoplastic Lining

Thermoplastic lining materials, due its light weight, low cost, easy manufacturing, waterproof, are widely used in all types of buildings to cover floors, walls and ceilings. When subject to fire, thermoplastic materials would release lots of toxic smoke, provide routes to adjacent zones through surface flame spread or melt flow flame spread, increase fire area, intensify and accelerate enclosure fire growth.Previous research was focused on 'thermoset' materials, which do not show melt flow in fire, and there were little research on thermoplastic linings, whose melting behavior makes it different from other materials. The aim of this thesis is to study the fire performance of thermoplastic linings. The most common commercial thermoplastic linings, PP, PE, PS, PMMA and PVC, were selected and tested on small scale and large scale experiments to explore their fire behavior.Small scale experiments were carried out on thermogravimetry and cone calorimeter respectively. Through thermogravimetric analysis, materials' thermal decomposition characteristics were studied, the process and kinetics of thermal decomposition were analyzed and discussed, which provided foundermental support for fire performence research on thermoplastics. Combustibility were studied through cone calorimeter, the effect of lining thickness and external irradiance levels on ignition, heat release rate and mass loss rate were investigated. Based on dimensionless analysis, numerical calculation and linear regression methods, formulae of ignition for thermally thin, intermediate thermally thick and thermally thick materials were established with applicable range given in the form of dimensionlessparameter for each formula, and the reliability were proved through comparison with experiments and literature.Since there are no published 'standard tests' capable of revealling real fire performance of thermoplastic linings, especially the melt flow behavior, a rig for test on fire behavior of thermoplastic linings was established based on the ISO9705 heat release rate measurement platform. The effect of material type, thickness, ignitor, flooring and melt flow viscosity were explored, the parameters such as heat release rate, pool and pool fire growth, lining surface temperatures, pool temperatures and flame height were obtained. Through the data analysis, two types of burning modes for thermoplastic linings, melt flow burning and solid surface burning, were discovered, the reasons for each mode were explained with the thermal decomposition mechanisms and the important factors affecting thermoplastic lining fire behavior were identified.Difficulties and advices for simulation of thermoplastic lining fire behavior were put forward based on expermtal research and literature. CFD software FDS was used to simulate solide surface burning process, and its applicability was discussed. A formula for upward flame spread without ignitor, which is proved to be capable of simulating the solide surface combustion, was deduced from the concurrent flame spread theory.