基于粒径分布的静电粉末喷涂上粉率研究

为研究粉末粒径分布对静电粉末喷涂上粉率的影响，采用不同目数标准检验筛将商用粉末涂料进行人工筛选。通过测量铝合金试样单位面积增质量来表征静电粉末喷涂一次上粉率，研究粉末涂料粒径分布对静电粉末喷涂一次上粉率的影响。此外，通过设计矩形凹槽模拟喷涂死角区，采用槽内试样单位面积增质量与槽外单位面积增质量的比值表征静电粉末喷涂死角上粉率，研究静电粉末喷涂死角上粉率随粉末涂料粒径分布的变化规律。结果表明：粒径分布为 30~50 μm粉末涂料的静电喷涂一次上粉率最高，而粉末粒径 ≤30 μm的粉末涂料死角上粉率最好。当静电粉末喷涂一次上粉率满足要求时，适当增加粉末涂料中超细粉末（ ≤10 μm）含量，将能改善喷涂死角区上粉率。

Research on the Deposition Efficiency of Powder During Electrostatic Spraying Based on Powder Particle Size Distribution

In order to study the effect of powder particle size distribution on the deposition efficiency of powder electrostatic spraying,the powder was manually screened using standard sieves with different meshes.The one-shot deposition efficiency of powder electrostatic spraying was characterized by measuring the mass increment on unit area of aluminum alloy samples,and the influence of particle size distribution of powder on the one-shot deposition efficiency of powder electrostatic spraying was studied.In addition,the rectangular groove was designed to simulate the spray blind area,and the ratio of the mass increment per unit area of the sample at the bottom of the groove to the mass increment per unit area outside the groove was used to characterize the deposition efficiency of the powder electrostatic spraying in blind area.At the same tim e,the variation of deposition efficiency of powder electrostatic spraying in blind area with powder particle size distribution was studied.The results showed that the powder with 30-50μm in particle size distribution would provide the highest one-shot deposition efficiency,while the powder with particle size≤30μm would provide the highest deposition efficiency in blind areas.When the one-shot deposition efficiency of powder electrostatic spraying met the requirements,appropriately increase of the content of ultra-fine powder(≤10μm)in the powder coatings would likely improve the deposition efficiency in blind areas.