GB/T 21782.5-2010 "Powder coatings - Part 5: Determination of fluidity of powder-air mixtures" specifies the determination method of fluidity of powder-air mixtures, which can effectively reflect the industrial practice of powder lame plating. The standard specifies the test principle, equipment requirements, operation steps and result calculation, and is suitable for evaluating the flow characteristics of powder coatings in actual lame plating. Factors affecting fluidity include the composition of powder coatings, density, particle shape, Particle size distribution, and the coacervation and triboelectric charge properties of the particles. This standard is proposed by the China Petroleum and Chemical Industry Federation and is under the jurisdiction of the National Coatings and Pigments Standardization Technical Committee. It was released on September 26, 2010 and implemented on August 1, 2011.