Research On Combustion Characteristics And Pyrolysis Kinetics Of Sealant In Aircraft Fire Zone

The sealing material is widely used in various types of aircraft,its performance directly affects the reliability while aircraft is taxiing and flighting.The sealing material is rarely applied to the aircraft,but it plays an important role in many important parts,such as the floor gap of the entrance threshold,fuel tank seal,engine nacelle fire seal and so on.Aircraft fire zone is an extremely dangerous area of aircraft,its sealing and fire performance directly affect the safety of the entire aircraft.Therefore,it is very significant to study the combustion characteristics and pyrolysis of sealants in aircraft fire zones.DAPCO 2200 sealant for large passenger aircraft fire area and PR812 sealant for general aircraft fire area were selected as test objects for comparative analysis.Two materials were analyzed by cone calorimetry analysis to their combustion characteristics,smoke generation characteristics and pyrolysis laws of in different simulated fire environments.The results showed that the peak heat release rate of DAPCO 2200 sealant reached 160.4 kW/m~2,and the total smoke production was up to 38.1 MJ/m~2;DAPCO 2200 sealant were studied by smoke density box analysis to its smoke characteristics in both simulated fire conditions of flame and flameless.The results showed that the flameless produced more flue gas than the flaming(443.5),while the mass loss was smaller.The airworthiness fire test results showed that the PR812 sealant had excellent performance in fireproof,heat insulation and sealing in high temperature environment;DAPCO 2200 sealant and PR812 sealant was studied by thermogravimetric-differential calorimeter analysis to their the law of pyrolysis reaction,thermal decomposition time and stage at different heating rates.The results showed that the pyrolysis of DAPCO 2200 sealant was divided into two stages,and the pyrolysis of PR812sealant was divided into three stages.DAPCO 2200 sealant has better thermal stability than PR812 sealant.Based on the above analysis show that DAPCO 2200 sealant is superior to PR812 fire sealant in fire resistance.