Process Of Basic Research On Laser Cleaning Technology Of Car Body Surface Paint

In the industrial field,in order to protect metals or other matrix materials,the surface is generally painted to achieve anti-rust,anti-oxidation and anti-corrosion effects.When the paint layer partially peels off or other reasons require repainting the surface,it is necessary to completely clean the original paint layer.In the automotive industry,before the overhaul of the car body,the old paint on the surface needs to be removed in order to spray new paint.There are many traditional vehicle body paint cleaning methods,mainly based on mechanical and chemical means.Among them,mechanical means include highpressure water jet lacquer removal,sandblasting or steel brush polishing,and chemical means mainly refers to chemical reagents lacquer removal.These methods have the disadvantages of high cost,high energy consumption,easy pollution,and easy to damage the surface of the substrate,and have gradually failed to meet the high requirements of modern environmental protection for cleaning methods.In response to this situation,many new types of cleaning technologies have emerged.Laser cleaning is one of the most important means and gradually shows its superiority.Selective removal,no substrate damage,fast cleaning rate is a key benefit of laser cleaning paint.The use of high power CO2 lasers,diode lasers and pulsed laser cleaning paints has continued to grow.However,the transmission and operation of the CO2 laser beam on the surface of the workpiece often become too complicated and difficult to apply.With the development of multi-kilogram fiber lasers,the research on paint ablation has gained new attention due to its high cleaning efficiency.In this paper,the laser cleaning experiment is carried out for the cleaning of the paint layer on the car body by the continuous fiber laser.The paint layer on the surface of steel and aluminum alloy is used as the cleaning object.The determination of the complete cleaning threshold,the mechanism of laser paint removal,and the reliability of laser cleaning The research was conducted on the aspects of sexuality,cleaning process parameters and influence laws.Firstly,the mechanism of interaction between laser and substrate surface contaminants and the mechanism of laser cleaning paints were analyzed.Comsol software was used to establish a three-dimensional thermal vibration model based on the actual condition of the car body to simulate the temperature and stress fields in the cleaning process for laser cleaning.The mechanism of the paint layer,the process of laser paint removal,and the cleaning and damage thresholds are closely related to the actual work.Secondly,orthogonal experiments and single-factor experiments were performed on the laser-removal paint on the surface of Q235 carbon steel.The orthogonal test and single-factor experiment on laser removal of various colors of paint and putty on aluminum alloy surface were performed to study the scanning speed,spot diameter,laser power,and scanning.The influence of factors such as the number of times on the cleaning quality is determined by analyzing the experimental results to find the ideal process parameters.Finally,while obtaining the ideal process parameters,it is necessary to ensure the safety problem,that is,whether the laser stripping has damage to the substrate.Therefore,the material properties of the plate after laser stripping and the plate without peeling were tested to analyze whether damage occurred and whether the performance of the repainting was affected.