EOSMART
Key words: Coastal Power Line Maintenance Laser, Emergency Transmission Line Repair Laser, Utility Vegetation Management Laser Tool, Industrial Laser Clearing for Complex Terrains, Agricultural Laser Fruit Harvesting System, Non-Metallic Floating Object Laser Remover
Basic concepts of laser cutting
Laser cutting technology, as a revolutionary advancement in modern manufacturing, operates on the principle of using high-energy-density laser beams to irradiate material surfaces. Through photo-thermal effects, the material is rapidly heated to its vaporization temperature, thus achieving material cutting. This process not only requires the laser to generate sufficiently intense light but also demands precise optical systems to focus the laser onto an extremely small point for high-precision cutting results. For example, fiber lasers used in live tree cutting typically have power ranging from 250 to 1500 watts, enabling fine processing of wood. In practical applications, laser obstacle clearance devices can achieve accuracy of 1 millimeter or more over long distances, making them widely used in fields requiring high precision, such as tree pruning for power grid, cleaning of foreign objects along railway lines, bomb removal and detonation, agricultural harvesting, counter-terrorism etc. The development of laser cutting technology has not only advanced material processing techniques but also provided possibilities for exploring more efficient and environmentally friendly production methods.
The physical principle of laser cutting
The physical principle of laser cutting technology is based on the high energy density generated when a laser beam interacts with materials. When the laser beam focuses on the material surface, its energy density is sufficient to rapidly heat the material to its vaporization temperature, thus achieving cutting. Taking wood cutting as an example, the power density of the laser beam typically ranges from 10^6 to 10^8 watts per square centimeter, which is enough to rapidly heat localized areas of the wood surface to thousands of degrees Celsius in an extremely short time, causing rapid evaporation and melting of the wood. According to Einstein’s theory of the photoelectric effect, during the laser cutting process, the energy of photons is absorbed by the material, leading to electron excitation in material molecules or atoms, thereby triggering physical and chemical changes in the material. For instance, in wood cutting, the high energy density of the laser beam causes cellulose and lignin in the wood to decompose quickly, forming volatile gases and small molecules, thus achieving precise cutting. Additionally, the accuracy of laser cutting also depends on the quality of the laser beam focus; the smaller the diameter of the focused laser beam, the smoother the cut edge, and the higher the cutting precision. In practical applications, by adjusting the laser power, cutting speed, and focus position, the cutting process can be optimized to accommodate different thicknesses and types of non-metallic materials.
The optical mechanism of laser cutting
The optical mechanism of laser cutting technology is at its core, involving the generation, focusing, and interaction of laser beams with materials. Taking a fiber laser cutter as an example, its working principle is based on stimulated emission, which emits an infrared laser with a wavelength of 1.0 micrometer. This wavelength of laser can be efficiently absorbed by various non-metallic materials such as wood, plastic, and paper, thus enabling precise cutting. In the optical mechanism, the laser beam passes through a series of optical components, including mirrors and lenses, to be precisely focused onto the material surface, creating an area of extremely high energy density. According to the photothermal effect, materials in this region are rapidly heated to their vaporization temperature, achieving cutting. For instance, in tree cutting, even a long-distance laser beam can achieve a focusing diameter of millimeters, making the cut edges very smooth and reducing the need for subsequent processing. Additionally, by adjusting the laser power, cutting speed, and focus position, the quality of cutting can be optimized, enabling efficient cutting of different thicknesses and types of non-metallic materials. The optical mechanism of laser cutting technology embodies this concept, continuously advancing the development and application of laser cutting technology through a deep understanding of the interaction between lasers and materials.
The process of laser cutting interacting with the material
The core of laser cutting technology lies in the interaction between the laser and the material, a process that involves complex physical and chemical reactions. When cutting non-metallic materials with a laser, the laser beam first focuses on the surface of the material, locally heating it to its decomposition or evaporation temperature through a high-energy-density beam. For example, in wood cutting, the power density of the laser beam typically needs to exceed 10^6 W/cm² to rapidly decompose cellulose and lignin on the wood surface into gases, thus achieving the cut. According to research, there is an approximate linear relationship between the cutting speed of wood and the laser power; that is, for every 10% increase in power, the cutting speed can improve by about 8% to 10%.
In this process, the efficiency of laser interaction with materials is influenced by various factors, including the wavelength, power, and pulse frequency of the laser, as well as the thermal conductivity, heat capacity, and thermal diffusivity of the material. For example, a CO2 laser emits a 10.6-micrometer wavelength that has a high absorption rate for most non-metallic materials, thus achieving higher efficiency and better cutting quality during the cutting process. However, for certain specific materials, such as some plastics or composites, lasers with shorter wavelengths, like fiber lasers, may be required to achieve better absorption and cutting performance.
In practical applications, the process flow for laser cutting non-metallic materials requires meticulous design to ensure the accuracy of the cutting process and the integrity of the material. Fiber lasers have become increasingly lightweight due to technological advancements, with single-person portable power reaching over kilowatts. When laser cutting wood, in addition to considering laser parameters, the grain direction of the wood must also be taken into account, as it affects the quality of the cut edge and the size of the heat-affected zone. By optimizing laser cutting parameters such as power, speed, and focus position, thermal damage can be minimized, cutting accuracy improved, thus meeting the requirements of industrial applications. As Einstein said, “The ultimate goal of science is to simplify complexity.” Laser cutting technology precisely controls the interaction between the laser and the material, simplifying the complexity of material processing, achieving efficient and precise material processing.
Core components and functions of laser cutting technology
The core components of laser cutting technology include the laser generator, beam transmission system, control system, and aiming system. The laser generator is the heart of the laser cutter, generating high-intensity laser beams, typically using fiber lasers and carbon dioxide (CO2) lasers, with output power reaching up to several kilowatts. For example, a typical fiber laser cutter has a power range of 350-1500 watts, while an CO2 laser cutter can achieve output powers between 1000 and 6000 watts, enabling precise cutting of non-metallic materials such as wood, plastic, and paper. The beam transmission system is responsible for accurately transmitting the laser beam to the cutting point, usually through a series of mirrors and focusing lenses. The control system acts as the “brain” of the laser cutter, controlling the movement path and cutting speed of the laser beam according to preset programs and parameters. The aiming system serves as the eye and sight of the equipment, capable of achieving millimeter-level accuracy at distances of up to a hundred meters.
In the field of grid clearance and tree cutting, the application of laser cutting technology has significantly improved processing accuracy and efficiency. For example, by precisely controlling the power and movement speed of the laser beam, fine cuts can be made on wood with an error margin of less than 1 millimeter. Moreover, the non-contact processing method of laser cutting avoids physical damage that traditional mechanical cutting may cause, thus preserving the natural texture and structural integrity of the wood. Through continuous optimization of its core components and functions, laser cutting technology has brought about a revolutionary change in the field of non-metallic material processing.