Laser Cleaning The traditional cleaning industry has a variety of cleaning methods, mostly using chemical agents and mechanical methods for cleaning. In China, increasingly stringent environmental protection regulations, people's growing awareness of environmental protection and safety, the types of chemicals that can be used in industrial production and cleaning will become less and less. How to find a cleaner and non-invasive cleaning method is a problem we have to consider. Laser cleaning is characterized by non-abrasive, non-contact, non-thermal effects and objects suitable for all kinds of materials. It is considered to be a very reliable and effective solution. At the same time, laser cleaning can solve problems that cannot be solved using traditional cleaning methods.
The advantages of laser cleaning
Compared with traditional cleaning methods such as mechanical friction cleaning, chemical corrosion cleaning, liquid solid strong impact cleaning, and high-frequency ultrasonic cleaning, laser cleaning has obvious advantages.
1. Laser cleaning is a "green" cleaning method. It does not use any chemicals and cleaning fluids. The cleaned waste is basically solid powder. It is small in size, easy to store, and can be recycled. It can easily solve the chemical cleaning belt. Environmental pollution problems
2. The traditional cleaning method is often contact cleaning, which has mechanical force on the surface of the cleaning object. The surface of the damaged object or the cleaning medium adheres to the surface of the object to be cleaned, and cannot be removed, resulting in secondary pollution.
3, fiber laser small size, can be matched with the robot hand and robot, easy to achieve long-distance operation, can clean the traditional method is not easy to reach the site, which can be used in some dangerous places to ensure the safety of personnel;
4. Laser cleaning can clean various types of contaminants on the surface of various materials to achieve cleanliness that cannot be achieved by conventional cleaning. And it can also selectively clean the surface of the material without damaging the surface of the material.
5, laser cleaning efficiency, save time;
6. Although the laser cleaning system was purchased at a higher initial investment, the cleaning system can be used stably for a long period of time. The operation cost is low, and more importantly, it can be easily automated.
Laser cleaning practical application
Laser cleaning can be used not only to clean organic contaminants, but also to clean inorganic materials, including metal corrosion, metal particles, and dust. The following describes some practical applications. These technologies have been very mature and have been widely used.
1, mold cleaning:
Every year, tire manufacturers in the world manufacture hundreds of millions of tires, and the tire molds in the production process must be quickly and reliably cleaned to save downtime. Conventional cleaning methods include sandblasting, ultrasonic or carbon dioxide cleaning, but these methods usually have to be cooled in a hot mold for several hours, then moved to the cleaning equipment for cleaning, cleaning takes a long time, and easy to damage the accuracy of the mold Chemical solvents and noise can also cause problems such as safety and environmental protection. The use of laser cleaning methods, because the laser can use optical fiber to transmit, so in the use of a highly flexible; because the laser cleaning can be used to connect the optical fiber to the die dead or not easy to clean the parts, so easy to use; Rubber does not gasify, so it will not produce poisonous gas, affecting the safety of the working environment. The technology of laser cleaning tire molds has been widely adopted in the tire industry in Europe and America. Although the initial investment cost is high, the benefits obtained in saving standby time, avoiding mold damage, working safety, and saving raw materials can be quickly recovered.
The anti-adhesive elastic film layer on food industry mold needs to be replaced regularly to ensure hygiene. The use of laser cleaning without chemicals is also particularly suitable for this application.
2. Weapon and equipment cleaning:
Laser cleaning technology is widely used in weapon maintenance. The laser cleaning system can clean and quickly clean the rust and contaminants, and can select the cleaning sites to realize the automation of cleaning. The use of laser cleaning not only has a higher degree of cleanliness than the chemical cleaning process, but also has little damage to the surface of the object.
3, aircraft old paint cleaning:
The European laser cleaning system has long been used in the aviation industry. The surface of the aircraft will be repainted after a certain period of time, but the original paint must be removed before painting. The traditional mechanical cleaning method is easy to damage the metal surface of the aircraft, causing hidden dangers to safe flight. If multiple laser cleaning systems are used, the paint on the surface of an A320 Airbus can be completely removed within two days without damaging the metal surface.
4. Cleaning of the external walls of buildings:
With the rapid development of China's economy, more and more skyscrapers have been established. The problem of cleaning the external walls of buildings has become increasingly prominent. It can effectively clean various pollutants on various types of stone, metal, and glass. The conventional cleaning efficiency is many times higher. It can also clean dark spots and stains on various types of stone in buildings.
5. Cleaning in the electronics industry
The electronics industry uses lasers to remove oxides: The electronics industry needs high-precision decontamination, which is particularly suitable for laser de-oxidation. Before the board is soldered, the component pins must be completely de-oxidized to ensure a good electrical contact. The pins must not be damaged during the decontamination process. Laser cleaning can meet the requirements of use, and the efficiency is very high. Only one laser beam is needed for one pin.
6. Cleaning in precision machinery industry:
The precision machinery industry often needs to clean the parts of the ester and mineral oil used for lubrication and corrosion resistance, usually chemical methods, and chemical cleaning tends to still have residues. The laser can completely remove the esters and mineral oil without damaging the surface of the parts. The removal of contaminants is accomplished by shock waves. The explosive vaporization of thin oxide layers on the surface of the part creates shock waves that cause the removal of dirt rather than mechanical interaction. The materials are thoroughly used in the cleaning of aerospace industrial machinery parts. Oil ester removal in the machining of mechanical parts can also be cleaned by laser.
7, nuclear power plant reactor pipe cleaning:
The laser cleaning system is also used for the cleaning of pipelines in reactors of nuclear power plants. It uses optical fiber to introduce high-power laser beams into the reactor and directly clean radioactive dust. The cleaned material is easy to clean. And because it is a long-distance operation, staff safety can be ensured.
In summary, laser cleaning plays an important role in many fields, such as automobile manufacturing, semiconductor wafer cleaning, precision parts processing and manufacturing, military equipment cleaning, building exterior wall cleaning, cultural relics protection, circuit board cleaning, precision parts processing and manufacturing. , Liquid crystal display cleaning, chewing gum residue removal and other areas can play an important role.
The main method of laser cleaning
There are four main laser cleaning methods:
1 laser dry-cleaning method, which uses pulsed laser direct radiation decontamination;
2 laser + liquid film method, that is to first deposit a layer of liquid film on the surface of the substrate, and then use laser radiation to decontaminate;
3 laser + inert gas method, that is, at the same time laser irradiation, with inert gas blown to the surface of the substrate, when the dirt peeled from the surface will be immediately blown away from the surface of the gas to avoid re-contamination and oxidation of the surface;
4 Use laser to loosen the dirt, then use non-corrosive chemical cleaning.
It is quite common to use the first three methods. The fourth method is only seen in the cleaning of stone artifacts.
Internationally, laser cleaning technology has been applied to the use of stone materials for more than ten years. In China, laser cleaning of stone materials started late. As the investment in laser equipment is still relatively expensive, it is still difficult to apply it universally. However, laser cleaning technology has the advantages that traditional cleaning methods cannot match. With the continuous improvement of technology and the mass production of equipment, laser cleaning technology will play an important role in the cleaning of stone materials.