The principle and method of 200W laser cleaning machine, laser is characterized by high directivity, absolute, high coherence and high brightness. Through the lens focus and Q switch can focus energy into a small space and time range. In laser cleaning treatment, the following characteristics of laser are mainly used:
1, laser energy can be realized in time and space of the high concentration of the focus of the laser beam near the focus can produce a thousand degrees or even ten thousand degrees of high temperature, make the dirt instant evaporation, gasification or decomposition.
2, the divergence Angle of the laser beam is small and good direction through the light concentrating system can make the laser beam focus into different diameter of the spot. Under the condition of the same laser energy, controlling the laser beam spot with different diameters can adjust the energy density of the laser so that the dirt is heated and expanded. When the expansion force of dirt is greater than the adsorption force of dirt on matrix, dirt will be separated from the surface of the object.
3, laser beam can produce mechanical resonance by producing ultrasonic wave on the solid surface to break off the dirt. Laser cleaning technology is the use of the characteristics of the above laser to achieve the purpose of cleaning.
According to the optical characteristics of the substrate material to be cleaned and the dirt to be removed, the laser cleaning mechanism can be divided into two categories 500W laser cleaning machine :
A cleaning substrate (also known as the matrix) and surface attachments (dirt) for a certain wavelength of laser energy absorption coefficient has a great difference. Most of the laser energy radiated to the surface is absorbed by the surface attachment, so as to be heated or vaporized, or expanded instantly, and driven by the airflow formed, it is separated from the surface of the object to achieve the purpose of cleaning. The substrate will not be damaged because it absorbs very little energy from the laser at this wavelength. For this kind of laser cleaning, choosing the right wavelength and controlling the laser energy is the key to realize the safe and efficient cleaning.
Another cleaning method is that there is little difference between the laser energy absorption coefficient of the clear lake and the surface attachment, or the substrate is sensitive to the acid vapor formed by the coating when it is heated, or the coating will produce toxic substances when it is heated. This method usually uses a pulsed laser with high power and high repetition rate to shock the cleaned surface and convert part of the beam into sound waves. When the sound waves hit the hard surface of the lower layer, the returning part interferes with the incident sound waves generated by the laser, resulting in high-energy waves that cause a small explosion of the coating. The coating is pressed into powder and then removed by the vacuum pump, but the underlying substrate is not damaged.
There are 4 kinds of laser cleaning methods from the method analysis:
1, laser dry cleaning method, namely the use of pulse laser direct radiation decontamination;
2, laser + liquid film method, that is, first deposit a layer of liquid film on the surface of the matrix, and then use laser radiation decontamination; When the laser is irradiated on the liquid film, the liquid film is heated rapidly to produce explosive vaporization, and the explosive shock wave loosens the dirt on the surface of the matrix. And fly away from the surface of the processed object with the shock wave to achieve the purpose of decontamination.
3, laser + inert gas method, that is, in the laser radiation at the same time, with inert gas blown to the surface of the matrix, when the dirt from the surface will be immediately blown from the surface of the gas, in order to avoid surface pollution and oxidation;
4, after the use of laser dirt loose.