Laser cleaning machines have shown good results in cleaning graffiti. According to research and experimental data, laser cleaning technology can effectively remove graffiti and has the following advantages:
1. Non-contact cleaning: Laser cleaning is a non-contact cleaning method that does not cause physical damage to the surface of the substrate.
2. High efficiency: Under appropriate laser energy density, laser cleaning can quickly remove graffiti. Experiments show that when the laser energy density is between 4 and 6 J/cm², the removal efficiency is the highest, and the graffiti area removed per unit energy exceeds 2.5 cm²/J.
3. Green and environmentally friendly: No chemical solvents are used in the laser cleaning process, and the waste generated during the cleaning process is in solid powder form, which is easy to store and does not pollute the environment.
4. Wide applicability: Laser cleaning technology can be used for a variety of substrates, including metal and non-metal materials, and has a wide range of applicability for pollutants such as graffiti.
5. Automated operation: Laser cleaning can be automated, and with the help of a robotic arm, remote, flexible, and precise cleaning can be achieved.
In the experiment, when the laser energy density was lower than 4 J/cm², the thermal effect was mainly responsible, but the removal effect was slow. When the laser energy density is between 4 and 6 J/cm², the mechanical impact effect caused by rapid laser heating and cooling is stronger than the thermal effect, which is the main mechanism of action, and the laser energy utilization efficiency is the highest at this time.
When the laser energy density exceeds 6 J/cm², the air on the sample surface is broken down, consuming a large amount of laser energy, and the removal efficiency is significantly reduced.
In summary, the laser cleaning machine is not only effective in cleaning graffiti, but also has the advantages of environmental protection, high efficiency, and non-destructiveness. It is an ideal cleaning method.
