Study on the Method of Coating Defect Elimination and Effect on Mechanical Properties

Abstract

The casting method in coating preparation has the advantages of short sample preparation period, small raw material loss, low cost, but the paint film often has bubble defects.The defects were characterized by microscope observation and density balance test. The influence of solvent content and ultrasonic shock on coating defects and the influence of defects on coating mechanical properties were investigated. The results show that the density decreases linearly with the increase of the number of bubbles. With the increase of solvent, the viscosity of paint decreases and the content of bubbles decreases obviously. As solvent increased, coating drying time increased, sample preparation period increased.After ultrasonic shock, bubbles in the surface of the paint and the cured coating were significantly reduced, compared with spraying sample preparation, ultrasonic shock sample preparation period was shortened by more than 30%.The samples with defective mechanical properties were broken during bubble emergence, the tensile strength and elongation at break were significantly reduced, and the dispersion was large, which was invalid data.