As a world-recognized manufacturing power, China has made great strides on the road of industrialization and made great achievements, but it has also caused serious environmental degradation and industrial pollution. In recent years, my country's environmental protection regulations have become more and more stringent, resulting in some enterprises being shut down for rectification. The one-size-fits-all environmental storm will have some impact on the economy, and changing the traditional polluting production model is the key. With the advancement of technology, people have gradually explored various technologies that are conducive to environmental protection, and laser cleaning technology is one of them. Laser cleaning technology is a workpiece surface cleaning technology that has been newly applied in the past ten years. It is gradually replacing traditional cleaning processes in many fields with its own advantages and irreplaceability.
Traditional cleaning methods include mechanical cleaning, chemical cleaning and ultrasonic cleaning. Mechanical cleaning uses scraping, rubbing, brushing, sandblasting and other mechanical means to remove surface dirt; wet chemical cleaning uses organic cleaning Spray, shower, soak or high-frequency vibration and other measures to remove surface attachments; ultrasonic cleaning method is to put the treated parts into the cleaning agent, and use the vibration effect generated by ultrasonic waves to remove dirt. At present, these three cleaning methods still dominate the cleaning market in my country, but they all produce pollutants to varying degrees, and their applications are greatly limited under the requirements of environmental protection and high precision.
4 types of laser cleaning methods
Laser cleaning technology refers to the use of high-energy and high-frequency laser beams to irradiate the surface of the workpiece, so that the dirt, rust or coating on the surface evaporates or peels off instantly, and effectively removes the surface attachment or surface coating of the cleaning object at high speed, so as to achieve a clean laser. crafting process. Lasers are characterized by high directivity, monochromaticity, high coherence and high brightness. Through the focusing and Q-switching of the lens, the energy can be concentrated into a small spatial and temporal range. Subdivided from the method, there are 4 types of laser cleaning methods:
1. Laser dry cleaning method, that is, decontamination by direct radiation of pulsed laser;
2. Laser + liquid film method, that is, first deposit a layer of liquid film on the surface of the substrate, and then decontaminate it with laser radiation; when the laser is irradiated on the liquid film, the liquid film is heated rapidly, resulting in explosive vaporization, and the explosive shock wave makes the surface of the substrate decontaminate. Dirt is loose. And fly away from the surface of the processed object with the shock wave to achieve the purpose of decontamination. 3. The method of laser + inert gas, that is, when the laser is irradiated, the inert gas is blown to the surface of the substrate. When the dirt is peeled off from the surface, it will be blown off the surface by the gas immediately to avoid re-contamination and oxidation of the surface;
4. Use the laser to loosen the dirt, and then use the non-corrosive chemical method to clean it. At present, due to the development of my country's high-end manufacturing industry and the continuous improvement of environmental protection requirements, traditional cleaning technologies (chemical methods and mechanical polishing methods) are far from meeting the needs of my country's industrial production. The backwardness of cleaning technology limits the normal production and operation of some important industries in my country. Therefore, as a representative of green and efficient manufacturing, laser cleaning technology has a broad market scale under the rapid development of my country's high-end manufacturing industry.
Compared with the traditional cleaning method, laser cleaning is a "green" cleaning method with incomparable advantages: no need to use any chemicals and cleaning solutions, and the cleaned waste is basically solid powder, small in size and easy to use. Storage, adsorption and recovery, no photochemical reaction, no noise and no environmental pollution, and no harm to the health of operators, easy to achieve automatic control, and remote remote cleaning.
Laser cleanaing application
Laser cleaning is widely used in various fields:
Mold cleaning
The laser can realize the non-contact cleaning of the mold, which is very safe for the surface of the mold, can ensure its accuracy, and can clean the sub-micron dirt particles that cannot be removed by traditional cleaning methods, so as to achieve truly pollution-free, efficient and high-quality cleaning. Precision deesterification cleaning in the precision instrument industry.
Precision machinery cleaning
The precision machinery industry often needs to remove esters and mineral oils used for lubrication and corrosion resistance on parts, usually chemically, and chemical cleaning often leaves residues. Laser deesterification can completely remove esters and mineral oils without damaging the surface of the parts. The laser promotes the explosive gasification of the thin oxide layer on the surface of the part to form a shock wave, which results in the removal of contaminants rather than mechanical interaction.
Rail cleaning
At present, all the pre-welding cleaning of rails adopts grinding wheel and abrasive belt grinding type cleaning, which causes serious damage to the substrate and serious residual stress, and consumes a lot of grinding wheel consumables every year, which is costly and causes serious dust pollution to the environment. Laser cleaning can provide high-quality and efficient green cleaning technology for my country's high-speed railway track laying production, solve the above problems, eliminate welding defects such as seamless rail holes and gray spots, and improve the stability and safety of my country's high-speed railway operation.
Aviation sector
The surface of the aircraft needs to be repainted after a certain period of time, but the original old paint needs to be completely removed before painting. Chemical immersion/wiping is the main paint stripping method in the aviation field. This method causes a large amount of chemical auxiliary waste, and cannot achieve local maintenance and paint stripping. The workload of this process is heavy and harmful to health. Laser cleaning enables high-quality removal of paint on aircraft skin surfaces and is easily automated for production. At present, this technology has been applied to the maintenance of some high-end models abroad.
Ship field
At present, the pre-production cleaning of ships mainly adopts the sand blasting method. The sand blasting method has caused serious dust pollution to the surrounding environment and has been gradually banned, resulting in the reduction or even suspension of production by ship manufacturers. Laser cleaning technology will provide a green and pollution-free cleaning solution for anti-corrosion spraying on ship surfaces.
Military field
Laser cleaning technology is widely used in weapon maintenance. The laser cleaning system can efficiently and quickly remove rust and contaminants, and can select the removal part to realize the automation of cleaning. Using laser cleaning, not only the cleanliness is higher than the chemical cleaning process, but also has almost no damage to the surface of the object.
Laser cleaning has unique advantages in the cleaning industry.
