With the high accuracy of the cleaning of stone have become increasingly demanding, and human environmental awareness, laser cleaning technology as a new cleaning method is being recognized and development. Laser cleaning technology mainly to high-speed laser beam to be cleaned effectively clean the surface of the attachment, it saves time, effort, water, and safe, reliable, wide application, easy to automatic control. Especially for stone carving, stone carving, stone face a variety of corners and other fine structure, and the age-old stone artifacts and other high stone cleaning, laser cleaning technology is that many traditional cleaning process can not be compared. Therefore, we can say that laser cleaning is a major advance in cleaning technology, promote the use of laser cleaning technology will make the stone even more powerful cleaning industry. From the surface; third dirt molecules will evaporate in an instant, gasification or decomposition. Laser cleaning technology is the use of laser pulses of vibration, thermal expansion and molecular particles of light the role of decomposition or phase change, or their three joint action to overcome the dirt and the matrix material bonding between the Slate, away from the surface to achieve cleaning purposes.
Matrix according to washing the optical properties of the material and dirt analysis, but also the mechanisms of laser cleaning is divided into two categories: one is the use of substrate material and surface adhesion of dirt on a wavelength of laser energy absorption coefficient difference between the laser full of energy absorbed by the dirt attached to thermal expansion or vaporization of volatile and is vaporized to form steam flow driven out of the matrix material to achieve the goal of cleaning, which countertop the matrix material on laser energy absorption coefficient is small.
Q dirt and stone surface of the main binding force of physical force and the weak chemical interactions. Weak chemical interactions, including the formation of hydrogen bonds and charge transfer bond energy and other physical forces, including van der Waals forces (including electrostatic, induction and dispersion) and the capillary force and so on. More difficult than other surface materials, stone cleaning is due to the existence of a large natural stone micro-pores, micro-pore capillary force dirt and stone not only between the various binding is enhanced, while its role so that all parcels kinds of cleaning the external hard work.
Laser is a very good color and direction of light radiation. Combination of focused beam through the mirror, the beam focused to a small area or region. Laser beam can produce at least three roles: First, the solid surface in the mechanical resonance phenomenon that cracked off the surface or coagulation; Second, the surface scale layer will overcome by the expansion of dirt particles in the matrix material on the adhesive force and they are not damaged, so the key to achieving safe and efficient cleaning is to choose the appropriate laser wavelength and to control moderate energy density. The other is the surface of the substrate material and attachment of the absorption coefficient of the laser beam is not very different, or heat the surface of attachment will produce toxic substances, etc. are usually used to clean high power pulsed laser frequency and the impact to be cleaned surface, so that part of the beam into sound waves, sound waves after the impact of hard surfaces in the lower back, the return portion of incident laser wave generated by the interference, resulting in high-energy resonant wave, so that small scale layer burst occurred, resulting in crushing, easy-to- material from the substrate surface.
For more than stone surface dirt cleaning mechanism is often combined use. Normally be processed according to the case of stone and dirt section of the frequency of laser pulses per second (0.5 to 30 pulses) and amplitude (8 to 25ns), so that the appropriate material absorbs light dirt. The frequency of the laser pulse repetition allows the impact of the role of porous stone surfaces and loose dirt Ko gap, when the laser is greater than the impact of substrate on the adsorption force dirt particles, dirt particles from the substrate to be cleaned purposes. When the laser photon energy is greater than (adhesion layer) dirt molecular bond energy, the laser photolysis, light exfoliation have to play effects, such as KrF excimer laser photon energy 5eV, greater than the organic dirt OO, HH, OH, CC, CH and NH chemical bonds such as bond energy, the laser can damage parts of the role of chemical bonds, decomposition of organic matter, which can be cleaned of organic oil. When the laser beam energy density further increases, a number of inorganic dirt. Such as those containing K, Na salt and the light from the decomposition of organic dirt and inorganic substances can be produced by expansion of laser heating to generate thermal stripping (ie, stripped of light) and from the substrate surface. To take full advantage of the various LASER role in strengthening the laser cleaning effect, often in advance on the surface of the substrate to be cleaned artificially put on some water or water mixed with methanol or ethanol liquid. When the laser light hits the film on, the liquid film due to rapid heating, will produce explosive vaporization, the explosion that loose dirt surface of the substrate and the substrate with surface wave departed, to the purpose of Mosaic. In this approach, although there are dirt particles in the particle vibration and thermal expansion, but the role of the explosive shock wave is the main, this method is also known as laser + film method in the matrix covered the surface of the liquid film thickness is 10 / m .
Matrix according to washing the optical properties of the material and dirt analysis, but also the mechanisms of laser cleaning is divided into two categories: one is the use of substrate material and surface adhesion of dirt on a wavelength of laser energy absorption coefficient difference between the laser full of energy absorbed by the dirt attached to thermal expansion or vaporization of volatile and is vaporized to form steam flow driven out of the matrix material to achieve the goal of cleaning, which countertop the matrix material on laser energy absorption coefficient is small.
Q dirt and stone surface of the main binding force of physical force and the weak chemical interactions. Weak chemical interactions, including the formation of hydrogen bonds and charge transfer bond energy and other physical forces, including van der Waals forces (including electrostatic, induction and dispersion) and the capillary force and so on. More difficult than other surface materials, stone cleaning is due to the existence of a large natural stone micro-pores, micro-pore capillary force dirt and stone not only between the various binding is enhanced, while its role so that all parcels kinds of cleaning the external hard work.
Laser is a very good color and direction of light radiation. Combination of focused beam through the mirror, the beam focused to a small area or region. Laser beam can produce at least three roles: First, the solid surface in the mechanical resonance phenomenon that cracked off the surface or coagulation; Second, the surface scale layer will overcome by the expansion of dirt particles in the matrix material on the adhesive force and they are not damaged, so the key to achieving safe and efficient cleaning is to choose the appropriate laser wavelength and to control moderate energy density. The other is the surface of the substrate material and attachment of the absorption coefficient of the laser beam is not very different, or heat the surface of attachment will produce toxic substances, etc. are usually used to clean high power pulsed laser frequency and the impact to be cleaned surface, so that part of the beam into sound waves, sound waves after the impact of hard surfaces in the lower back, the return portion of incident laser wave generated by the interference, resulting in high-energy resonant wave, so that small scale layer burst occurred, resulting in crushing, easy-to- material from the substrate surface.
For more than stone surface dirt cleaning mechanism is often combined use. Normally be processed according to the case of stone and dirt section of the frequency of laser pulses per second (0.5 to 30 pulses) and amplitude (8 to 25ns), so that the appropriate material absorbs light dirt. The frequency of the laser pulse repetition allows the impact of the role of porous stone surfaces and loose dirt Ko gap, when the laser is greater than the impact of substrate on the adsorption force dirt particles, dirt particles from the substrate to be cleaned purposes. When the laser photon energy is greater than (adhesion layer) dirt molecular bond energy, the laser photolysis, light exfoliation have to play effects, such as KrF excimer laser photon energy 5eV, greater than the organic dirt OO, HH, OH, CC, CH and NH chemical bonds such as bond energy, the laser can damage parts of the role of chemical bonds, decomposition of organic matter, which can be cleaned of organic oil. When the laser beam energy density further increases, a number of inorganic dirt. Such as those containing K, Na salt and the light from the decomposition of organic dirt and inorganic substances can be produced by expansion of laser heating to generate thermal stripping (ie, stripped of light) and from the substrate surface. To take full advantage of the various LASER role in strengthening the laser cleaning effect, often in advance on the surface of the substrate to be cleaned artificially put on some water or water mixed with methanol or ethanol liquid. When the laser light hits the film on, the liquid film due to rapid heating, will produce explosive vaporization, the explosion that loose dirt surface of the substrate and the substrate with surface wave departed, to the purpose of Mosaic. In this approach, although there are dirt particles in the particle vibration and thermal expansion, but the role of the explosive shock wave is the main, this method is also known as laser + film method in the matrix covered the surface of the liquid film thickness is 10 / m .
没有评论:
发表评论