The principle of laser cleaning
1、Selective evaporation
Different materials have different laser energy absorption rates of specific wavelengths, and when the absorption rate of the adhesion on the surface of the material is greater than the absorption rate of the substrate, the temperature of the adhesion can be instantly raised above the melting point and vaporization occurs through laser irradiation.
Typical applications:
Tire mold cleaning
Laser paint removal
Clean up carbon deposits
2、Transient surface heat effect
When the laser pulse scans the surface of the workpiece at high speed, the temperature in this area will increase instantaneously and then decrease, generating thermoelastic pressure. Due to the different thermal expansion coefficients of the adhesion and the substrate, the surface stress is unevenly distributed, so that the adhesion peels off from the substrate.
Typical applications:
3、Shock effect
The high energy density of the pulsed laser vaporizes the adherent and generates instantaneous high temperatures around it, while ionizing the vaporized material to produce plasma. With the continuous irradiation of the laser, the plasma locally generates high temperature and high pressure, and further generates a shock wave, so that the underlying material is microscopically compressed and fragmented. When the laser pulse stops, the plasma instantly generates a negative pressure, which takes away the attached particles generated by the compression.
Typical application: laser removal of metal oxide layers