The scientific name of laser cleaning is laser ablation or photoablation, which is the process of removing material from a solid (or sometimes liquid) surface by irradiating it with a laser beam. At low laser flux, the material is heated by the absorbed laser energy and evaporates or sublimates. Under high laser flux, the material is usually converted to plasma. Generally, laser ablation refers to the removal of material with a pulsed laser, but if the laser intensity is high enough, a continuous wave laser beam can be used to ablate the material. Excimer lasers of deep ultraviolet light are mainly used for photoablation. The wavelength of the laser used for photoablation is about 200 nm.

Moreover, laser energy can be selectively absorbed by coatings (especially metals). Therefore, CO2 or Nd: YAG pulsed lasers can be used to clean the surface and remove paint or coatings. The surface and the lower surface to be sprayed will not be damaged.

At present, laser cleaning equipment has 100W-1000W, which is very suitable for tires and steel. Compared with traditional dry ice and pickling, laser cleaning has the effects of low cost, environmental protection, and short investment recovery period. It is an upgrade of industrial dry ice and pickling.

Laser cleaning can be used not only to clean organic pollutants, but also to clean inorganic substances, including metal corrosion, metal particles, dust, etc. The following introduces what is the technical principle of the laser cleaning machine.

The cleaning process of pulsed Nd:YAG laser relies on the characteristics of the light pulse generated by the laser, based on the photophysical reaction caused by the interaction between the high-intensity beam, the short-pulse laser, and the pollution layer. The physical principles can be summarized as follows:

1. The light beam emitted by the laser is absorbed by the contamination layer on the surface to be treated.

2. The energy density of the laser can be adjusted to make the dirt expand by heat. When the expansion force of the dirt is greater than the adsorption force of the dirt to the substrate, the dirt will be separated from the surface of the object.

3 The light pulse width must be short enough to avoid heat accumulation that damages the surface to be processed.

4. The divergence angle of the laser beam is small and the directivity is good. The laser beam can be condensed into spots of different diameters through the condensing system.

5. Absorption of large energy forms a rapidly expanding plasma (a highly ionized unstable gas), which generates shock waves.

Each laser pulse removes a certain thickness of contamination layer. If the contamination layer is relatively thick, multiple pulses are required for cleaning. The number of pulses required to clean the surface depends on the degree of surface contamination. An important result produced by the two thresholds is the self-control of cleaning. The light pulse whose energy density is higher than the first threshold will keep out contaminants until it reaches the base material. However, because its energy density is lower than the destruction threshold of the base material, the base will not be damaged. Wuhan Ruifeng Optoelectronics laser equipment is cost-effective. With years of laser research and development experience, the product technology is mature and the product performance is safe and stable. Ruifeng Optoelectronics Laser has always adhered to the attitude of “quality first, service second, price third” to provide customers with the best quality products and services.

The above is the technical principle of laser cleaning machine. Compared with traditional cleaning methods such as mechanical friction cleaning and chemical corrosion cleaning, laser cleaning has obvious advantages. It is efficient, fast, low-cost, and has low thermal load and mechanical load on the substrate. The cleaning is non-damaging; it does not harm the health of the operator; the cleaning process is easy to realize automatic control and realize remote remote control cleaning. It can be seen that laser cleaning technology will gradually replace some of the traditional cleaning methods in the future.

Laser cleaning:

Laser cleaning technology uses nanosecond or picosecond pulsed lasers to irradiate the surface of the workpiece to be cleaned, so that the surface of the workpiece absorbs the focused laser energy instantly, forming a rapidly expanding plasma (a highly ionized unstable gas), making it Surface oil stains, rust spots, dust residues, coatings, oxide layers or film layers are vaporized or peeled off, so as to efficiently remove surface attachments.

1. Applicable substrate

In the field of industrial applications, laser cleaning objects are divided into two parts: the substrate and the cleaning object. The substrate mainly includes the surface contamination layer of various metals, semiconductor wafers, ceramics, magnetic materials, plastics, and optical components. The cleaning objects mainly include facing In the industrial field, there are a wide range of application requirements for rust removal, paint removal, oil removal, film/oxidation removal, and resin, glue, dust and slag cleaning.

2. Advantages of laser cleaning

Currently widely used cleaning methods in the cleaning industry include mechanical cleaning, chemical cleaning and ultrasonic cleaning, but under the constraints of environmental protection and the requirements of the high-precision market, their application is greatly restricted. The laser cleaning machine has obvious advantages in various industries.

1) Automated assembly line: The laser cleaning machine can be integrated with CNC machine tools or robots to implement remote control and cleaning, which can realize the automation of equipment, form a product assembly line operation, and intelligent operation.

2) Accurate positioning: Use optical fiber to transmit and guide the laser to make it flexible, and use the built-in scanning galvanometer to control the high-speed movement of the light spot, which is convenient for non-contacting of special-shaped parts, holes, grooves and other parts that are difficult to reach by traditional cleaning methods. Ground laser cleaning treatment.

3) No damage: Short-term impact will not heat the metal surface and cause no damage to the substrate.

4) Good stability: The pulse laser used in the laser cleaning machine has a long service life, usually up to 100,000 hours, with stable quality and good reliability.

5) No environmental pollution: no chemical cleaning agent is needed, no cleaning waste liquid is generated, and the pollutant particles and gas generated during the laser cleaning process can be collected and purified by the portable exhaust fan to avoid environmental pollution.

6) Low maintenance cost: There is no consumption of consumables during the use of the laser cleaning machine, and the operating cost is low. In the later stage, only the lens needs to be cleaned or replaced regularly. The maintenance cost is low and close to maintenance-free.

3. Application industry

Typical applications of laser cleaning include: mold cleaning, industrial rust removal, old paint and film removal, pre-welding and post-welding treatment, deesterification of precision parts, decontamination and deoxidation of electronic components, and cultural relics cleaning. It is widely used in metallurgy, molds, automobiles, hardware tools, transportation, construction home appliances, machinery and other industries.

Traditional cleaning processes, such as mechanical friction cleaning, chemical corrosion cleaning, etc., are very time-consuming, cannot be automated, and usually cause harmful effects on the environment. At the same time, there is no reliable way to measure the cleaning effect. In contrast, laser cleaning has the advantages of no pollution, no consumables, low cost, high efficiency, no contact, no stress, no damage, good controllability, precision cleaning of selectable areas, and the ability to clean difficult to reach dangerous areas. , Is considered to be a reliable and effective solution to cleaning problems in the future. The following describes the cleaning benefits of using a laser cleaning machine.

1. Can be accurately positioned. The laser beam can be accurately positioned on the surface of the material to be cleaned, and its spot area can be adjusted from a few tenths of a millimeter to 1 cm. Can clean irregular or relatively hidden surfaces. The laser head or the laser-conducting fiber can be accurately positioned on a movable three-dimensional platform, and the laser beam can be positioned on the surface of the material to be cleaned. Computer control can be used to make this positioning more precise and automated.

2. Laser cleaning can remove different types of pollutants on the surface of various materials to achieve a high degree of cleanliness. Laser cleaning has been successfully used to clean different dirt on various materials such as marble, limestone, sandstone, pottery, alabaster, plaster of paris, aluminum, bone, vellum and organic matter. The types of dirt include dust and mud. , Rust, paint, oil stains, etc.

3. Environmental protection of laser cleaning. The waste of laser cleaning is basically solid powder, small in size, easy to store, and basically does not cause pollution to the environment. It is a “green” cleaning process.

4. The non-contact of laser cleaning. The traditional method is often close-range operation, which has mechanical force on the surface of the cleaning object, and it is easy to damage the surface of the object. The laser cleaning is a non-contact processing, which can easily realize long-distance operation. It can be transmitted through optical fibers, combined with a robot or manipulator, and can clean parts that are not easily reached by traditional methods. Transfer energy in the form of light without mechanical contact. In this way, the surface of very fragile materials can be cleaned.

5. The laser cleaning equipment can be used stably for a long time, generally only requires electricity and maintenance costs, low operating costs, and can be easily automated. Wuhan Ruifeng Optoelectronics Laser is one of the first batch of laser equipment manufacturers, with more than ten years of R&D and production experience, leading peer companies in technology and integration. Since its establishment, the company has always paid attention to the research and development of laser technology and the development needs of customers, and is committed to providing each customer with complete material processing solutions.

6. It can effectively remove micron-sized and smaller polluting particles. The scale of some pollutants may reach the micron or even sub-micron level, such as dust particles in the etching and spraying process of electronic printed circuit boards. It is difficult to remove such contaminants by ordinary methods. At present, short-pulse ultraviolet lasers have been successfully used to remove tiny particles with a surface size of about 0.1 μm, and they have been applied in industrial production.

The above are the cleaning benefits of using a laser cleaning machine. 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.

The main problems of traditional cleaning methods include: negative impact on the environment and wear on the substrate. The sandblasting system generates a lot of waste and damages the fine surface of the substrate; while cleaning with chemical solvents, it will generate potentially dangerous steam and liquid waste. The shortcomings of traditional cleaning methods have prompted the application of laser technology in the field of surface cleaning. Due to the many advantages of laser cleaning machines, it has now become the most effective way to remove unwanted substances on the surface of materials.

Application fields of laser cleaning machine:

1. Removal of coating layer on metal or glass surface and quick paint removal.

2. Quickly remove rust and various oxides.

3. Remove grease, resin, glue, dust, stains and production residues.

4. The metal surface is roughened, and the metal surface is cleaned in a narrow space.

5. Paint removal, rust removal, oil removal before welding or before bonding, oxide and residue treatment after welding.

6. Mold cleaning, such as tire molds, electronic molds, and food molds.

7. Oil stains are removed after the production and processing of precision parts.

8. Quick cleaning of nuclear power components maintenance.

9. Oxide treatment, paint removal and rust removal during the production or maintenance of aerospace weapons and ships.

10. Cultural relics cleaning, rock cleaning, and building exterior surface cleaning. Wuhan Ruifeng Optoelectronics Laser is one of the first batch of laser equipment manufacturers, with more than ten years of R&D and production experience, leading peer companies in technology and integration. Since its establishment, the company has always paid attention to the research and development of laser technology and the development needs of customers, and is committed to providing complete material processing solutions for each enterprise.

The laser cleaning machine is simple to operate, that is, it can be cleaned without chemical reagents, media, dust, and water. It can automatically focus, clean with curved surfaces, and has the advantages of high cleanliness. It can remove resin, oil, stains, and dirt on the surface of objects. , Rust, coating, plating, paint.