Study On Flame Retardant Property And Low Smoke Of Epoxy Waterborne Ultra-Thin Steel Structure Fire-Retardant Coatings

In this paper,focusing on improving the flame retardant effect and the low-smoke problem of fire-retardant coatings,epoxy waterborne ultra-thin steel structure fireretardant coatings are selected as research objects,and the ranges of each composition ratio are determined.By adjusting the ratios,the effects of various components and different ratios on the properties of smoke and flame retardant about epoxy-type waterborne ultra-thin steel structure fireproof coating are investigated.Finally,it is recommended for this type of fire retardant coatings with reducing the risk of smoke and ensuring flame retardant performance.The main components such as epoxy resin emulsion,ammonium polyphosphate?APP?,pentaerythritol?PER?and melamine?MEL?were used as different factors in the experimental design,and the random distribution method was used to generate the random levels of the factors to carry out the formula design.The experimental data were obtained by static smoke density test method,cone calorimeter method,large plate combustion method,expansion volume test and ect.The Maximum Smoke Density,Average Smoke Density,Total Smoke Rate,Extinction Coefficient,Specific Extinction Area,and Carbon monoxide yield were used to characterize the smoke hazard of different samples.The flame retarding effect of different samples was characterized by the temperature rise of the steel plate in the large plate combustion method,the sample expansion volume,the Feat Release Rate,Time to Ignition and Ignition to Flameout.In order to obtain reliable conclusions on the relationship between each component and flame retardant smoke performance,the ways in this paper are using the results of each parameter to study and analyze the flame-retardant process mechanism of fire retardant coatings in detail,and combined with SPSS,Matlab and other software to finish the quantitative analysis between the composition content and properties.Finally,from the view of randomness and uniformity of experimental formula design,compare the comprehensive evaluation of flame retardant and smoke generation performance of each proportioning sample,and provide matching recommendations that meet the requirements of the test.It is shown that in terms of smoke generation,accelerating the carbonation rate of the flame retardant system is effective to promote the low smoke of the fireproof coating,which is achieved by destroying the continuous combustion of it.When the fire retardant coating is heated in the early stage,with the polymer properties and melamine foaming action,it will become molten and foamed,and a large amount of smoke is generated.As the degree of carbonization increases,the release of smoke gradually decreases.As a carbon-forming catalyst,compared with other main components,ammonium polyphosphate?APP?has a significant inhibitory effect on the production of smoke.In the basic formulation of the epoxy water-based ultra-thin steel structure fireproof coating involved in the test,the relationship between the content and the maximum smoke density can be expressed by curve fitting: Y =208.18-1256.75x₁ +2214.75x₁².Pentaerythritol has a promoting effect on raw tobacco,and its curve fitting function is: Y =49.89-718.97 x₂ +5900.58x₂².In addition,when the content of ammonium polyphosphate is 25% 30% in the fourcomponent system and 5% 8% about the pentaerythritol,the maximum smoke density will be the smallest.Taken together,when the ratio of ammonium polyphosphate to pentaerythritol was large,it is often beneficial to achieve suppression of smoke.The flame retardant effect of this type of coating should be considered in terms of both fire resistance and carbon layer insulation properties.It is shown that in the tests,the expanding and foaming effect of melamine is obvious.Although it has a certain effect on the flame retardant effect of the coating,but it is not completely positively correlated.When melamine accounts for more than 1/3 of the quality of the flame retardant system,it will be beneficial to the foam expansion of the coating,but it will reduce the fire resistance of the coating,and the dripping phenomenon will occur,reducing the flame retardant effect of the coating.However,if its content was little,the degree of foaming will be low and the amount of smoke released will be increased.Through comprehensive comparison and reseach,it was found that when the ratio of ammonium polyphosphate?APP?,pentaerythritol?PER?,melamine?MEL?and epoxy resin emulsion was about 3.4:1:1.7:7.2,it can effectively achieve low smoke generation under the premise of ensuring the fireproof effect of this type of fire retardant coating.