改善波形梁钢护栏表面涂层均匀性的方法探讨

Some Methods to Improve the Surface Coating Uniformityof Corrugated Sheet Steel Beams

影响热镀锌层均匀性的主要因素是锌液中的铝含量和吹拭工艺。在锌液中加入适当的铝元素,可以明显改善锌液的流动性,提高镀锌层表面光洁度,从而达到提高镀锌层均匀性、降低锌消耗的目的。将内吹环的结构形式由点状改为环状,使其吹拭力分布更加均匀,也有利于镀锌层的均匀性。锌层厚度在39~50μm,平均锌层厚度45μm,锌层散差值小于11μm。选择室温-中温磷化前处理工艺,确定磷化液优化配方参数;采用10把外带电静电喷枪对称布置,优化了静电场分布、压缩空气压力、环境温湿度、日常维护、操作技能等。根据聚酯粉末的特点,优化了聚酯粉末的配方和粒径,重点是改善边角处涂层的均匀性。塑层厚度在76~109μm,平均塑层厚度89μm,散差值小于33μm。按照改善后的方法生产出的产品,均符合GB/T31439.1-2015《波形梁钢护栏》的要求。

The main factors affecting the uniformity of hot-dip galvanized+electrostatic spraying corrugated sheet steelbeams are the aluminum content in zinc solution and the blowing process.By adding appropriate aluminum elements intozinc solution, the fluidity of zinc solution can be improved obviously, and the surface finish of zinc coating can beimproved, so as to improve the uniformity of zinc coating and reduce the consumption of zinc.The structure of inner blowring is changed from point to ring to make the blow force distribution more uniform, which is also beneficial to theuniformity of galvanized layer.The thickness of zinc layer is between 39-50μm, the average thickness of zinc layer is45μm, and the divergence value of zinc layer is less than 11μm.The main pretreatment process, spray gun configuration,coating powder composition and particle size that affect the uniformity of electrostatic coating.The optimal formulationparameters of phosphating solution were obtained by selecting room temperature - medium temperature phosphatingpretreatment process.Adopt 10 external electrostatic spray gun symmetrical arrangement, optimize electrostatic fielddistribution, compressed air pressure, ambient temperature and humidity, daily maintenance, operation skills,etc.According to the characteristics of polyester powder, the formulation and particle size of polyester powder wereoptimized.The thickness of plastic layer is between 76-109μm, with an average thickness of 89μm and a divergence valueless than 33μm. The performance of the products produced by the improved method meets the requirements of GB / T31439.1-2015 'corrugated beam steel guardrail'.