Laser cutting technology is characterized by controllable processing, high efficiency, and high quality, and has a wide range of applications in industrial processing, such as the automotive industry, textile machinery, and sheet metal processing. Laser cutting can be divided into four categories: laser vaporization cutting, laser melting cutting, laser oxygen cutting, and laser scribing and controlled fracture. Because my country's laser technology started relatively late, core cutting technologies rely on imports, which has led to the slow development of high-end laser cutting in China.
Laser cutting machine
A laser cutting machine is the most direct embodiment of laser cutting technology. It takes a laser beam emitted from a laser source, focuses it into a high-power-density laser beam through an optical path system, and then directs the beam onto the workpiece surface, causing the workpiece to reach its melting or boiling point. Simultaneously, high-pressure gas, coaxial with the beam, blows away the molten or vaporized metal. As the relative position of the beam and the workpiece moves, a kerf is eventually formed in the material, thus achieving the purpose of cutting.
As a new type of sheet metal processing equipment, laser cutting machines have become increasingly familiar and accepted by sheet metal processing companies due to continuous technological updates and process development. With its high processing efficiency, high precision, good cut surface quality, and ability to perform three-dimensional cutting, it is gradually replacing traditional sheet metal processing methods such as plasma cutting, water jet cutting, flame cutting, and CNC punching. Based on the different laser generators used, laser cutting machines on the market can currently be broadly classified into three types: CO2 laser cutting machines, solid-state (YAG) laser cutting machines, and fiber laser cutting machines.
Features of laser cutting machines
YAG Solid State Laser Cutting Machine
YAG solid-state laser cutting machines are characterized by low price and good stability, but their energy efficiency is low, generally <3%. Currently, most products have an output power below 800W. Due to the low output energy, they are mainly used for drilling and cutting thin plates. Its green laser beam can be used in pulsed or continuous wave mode, featuring a short wavelength and good focusing properties, making it suitable for precision machining, especially effective for hole machining under pulsed conditions. It can also be used for cutting, welding, and photolithography. The wavelength of the YAG solid-state laser is not easily absorbed by non-metals, therefore it cannot cut non-metallic materials. Furthermore, a key challenge for YAG solid-state laser cutting machines is improving the stability and lifespan of lithium-ion batteries, requiring the development of high-capacity, long-life optically pumped excitation sources. Using semiconductor optical pumps could significantly increase energy efficiency.
Key advantages: It can cut aluminum plates, copper plates, and most non-ferrous metals that other laser cutting machines cannot cut. The machine is inexpensive to purchase, has low operating costs, and is easy to maintain. Most of the key technologies have been mastered by domestic companies, and the price of spare parts and maintenance costs are low. In addition, the machine is easy to operate and maintain, and does not require high skill levels from workers.
Fiber laser cutting machine
Fiber laser cutting machines offer unprecedented flexibility, fewer potential points of failure, easier maintenance, and higher speed due to their ability to transmit signals via optical fiber. Therefore, they have a significant advantage when cutting thin plates up to 4mm thick. However, due to the limitations of solid-state laser wavelength, the quality is poor when cutting thicker plates. The wavelength of a fiber laser is 1.06µm, which is not easily absorbed by non-metals, thus it cannot cut non-metallic materials. Fiber lasers boast a photoelectric conversion efficiency of over 25%, offering significant advantages in terms of electricity consumption and cooling systems. According to international safety standards, laser hazards are classified into four levels. Fiber lasers, due to their short wavelength, pose a significant risk to the eyes, placing them in the highest level of hazard. Therefore, for safety reasons, fiber laser processing requires a fully enclosed environment.
Key advantages: High photoelectric conversion rate, low power consumption, capable of cutting stainless steel and carbon steel plates up to 12mm thick, making it the fastest laser cutting machine for thin plates among these three types of machines, with fine kerf and good spot quality, suitable for precision cutting.
CO2 laser cutting machine
CO2 laser cutting machines can stably cut carbon steel up to 20mm thick, stainless steel up to 10mm thick, and aluminum alloys up to 8mm thick. The wavelength of a CO2 laser is 10.6µm, which is easily absorbed by non-metals, allowing for high-quality cutting of non-metallic materials such as wood, acrylic, PP, and plexiglass. However, the photoelectric conversion efficiency of CO2 lasers is only about 10%. CO2 laser cutting machines are equipped with nozzles at the beam exit that spray oxygen, compressed air, or inert gas N2 to improve cutting speed and the smoothness of the cut. To improve power supply stability and lifespan, the discharge stability of high-power CO2 lasers needs to be addressed. According to international safety standards, laser hazard levels are divided into four levels, with CO2 lasers belonging to the lowest level.
Key advantages: High power, typically between 2000-4000W, capable of cutting full-size stainless steel, carbon steel, and other common materials up to 25mm thick, as well as aluminum sheets up to 4mm thick, acrylic sheets up to 60mm thick, wood panels, and PVC sheets, with high cutting speed when cutting thin sheets. Furthermore, because the CO2 laser outputs continuous laser light, it produces the smoothest and best cut surface among these three types of laser cutting machines.
Advantages of laser cutting technology in lithium-ion battery manufacturing
The lithium battery processing demands high precision, controllability, and the quality of the processing machinery. However, die-cutting blades inevitably wear down during use, leading to dust shedding and burrs, which can potentially cause dangerous problems such as battery overheating, short circuits, and explosions. To prevent these hazards, laser processing is more suitable. Compared to traditional machining, laser processing offers advantages such as no tool wear, flexible cutting shapes, controllable edge quality, higher precision, and lower operating costs.
Before the advent of laser technology, the battery industry used traditional machinery for processing. Compared with traditional machining, laser processing has advantages such as no tool wear, flexible cutting shapes, edge quality control, higher precision, and lower operating costs, which helps to reduce manufacturing costs, improve production efficiency, and significantly shorten the die-cutting cycle of new products.
