Research On Process Stability Of Grey Coating Material With Low Emissivity Based On Al-PU

The grey coating with low infrared emissivity,low lightness and gloss has important application prospect in military and national defense.In our laboratory,the low emissivity coating with excellent performance was prepared by nano pigment,but some stability problems could be arise.Firstly,the performance of the coating is not uniform enough in a area,Secondly,the performance of each batch coating can not be repeated stably in multi-batch preparation;the third is that the performance of the coating will deteriorated sharply when the coating is in mass production.Therefore,it is of great significance to study and control the process stability of coating materials and make it reach the engineering application.According to the above problems of the coating in application,the paper aims at the optimization,stability and mass production of preparation process.The influence of construction process,raw material parameters and mass production process on the coating properties and distribution of aluminum powder was discussed.The process parameters of the coating with stable performance and excellent technical parameters have been selected,and the engineering application of the grey coating with low emissivity has been realized.The main research results of this paper are as follows:1.The arranged closely distribution of pigment is the key of coating with stable performance.Optimizing the construction process,locating the physical and chemical parameters of the aluminum powder,selecting the suitable dispersing equipment and controlling the process parameters can make the pigment achieve a close and orderly arrangement in the coating.2.The viscosity of the construction at 14s~18s,curing temperature at 20℃~30℃,spraying pressure at 0.4MPa,the emissivity is around 0.15,the discrete range decreased from 0.1~0.35 to about 0.1~0.2,the average deviation of the maximum of 0.15 is reduced to about 0.02.The properties of the coating to achieve uniform stability.3.When the solid content of aluminum powder is in the 62%~66%,and the particle size is in 12μm ~17μm,the emissivity is in the 0.1~0.15,the brightness can be maintained at 50~54,the gloss can be maintained in 5~7,and coating can meet the requirements of repeated stability.4.When using the high-speed dispersion machine,the dispersion time is 1.5h,the speed control is more than 3000r/min,the obtained coating emissivity is 0.13,brightness is about 51;the gloss is below 8.The obtained coating basically achieve mass production.