How to Choose Between Fiber Laser Cutting Machine and Co2 Laser Cutting Machine?

Judging from the number of laser machines sold in my country's sheet metal equipment market in recent years, CO2 laser machines account for 40%, while fiber laser machines account for 60%. Although 100% of the laser machines sold on the market in 2007 were CO2 laser machines, we know that fiber laser machines have gained momentum in recent years and are being recognized by the market, and the number of units sold is gradually expanding.

Laser equipment is increasingly used in various industries due to its excellent performance. Laser equipment can be roughly divided into: laser cutting machines, laser engraving machines, laser marking machines, laser slicing machines, laser medical equipment, and other laser equipment. The laser cutting machines currently on the market for material cutting can be roughly divided into two types: fiber laser cutting machines and CO2 laser cutting machines.

If you want to know how to choose a laser cutting machine, you first need to know the basic differences between fiber lasers and CO2 lasers.

1. Different luminescent media

Fiber laser generates laser light through diode pumping and uses flexible fiber optic cables to transmit the laser beam, while CO2 laser generates laser light by exciting nitrogen and carbon dioxide gases in the cavity, and then transmits the beam through a reflector.

2. Different structures

At the same power, fiber lasers are more compact than CO2 lasers.

3. Different electro-optical conversion efficiencies

Generally, the conversion efficiency of CO2 laser is about 10%, and the conversion efficiency of fiber laser is about 30%.

4. Laser wavelengths are different

The wavelength of fiber laser is 1.06μm, and the wavelength of CO2 laser is 9.3μm~10.6μm. Therefore, the focused spot of the fiber laser is smaller than that of the CO2 laser, the cutting speed is fast, and the processing efficiency is higher.

So, since fiber lasers have so many advantages, isn’t it obvious how to choose between them? Its existence is reasonable, and CO2 laser also has its advantages.

Different cutting materials have different light absorption rates at different wavelengths. Non-metallic materials such as wood boards, cloth, plastics, acrylic, etc. have very low absorption rates for fiber lasers, while CO2 lasers have high absorption rates for both metallic and non-metallic materials. , so fiber laser is only suitable for cutting metal materials, while CO2 laser can be used for cutting both metal and non-metal materials. Moreover, the cutting surface of the CO2 laser has good smoothness and high verticality, making it more suitable for cutting materials with high precision requirements.

Therefore, in the metal sheet industry, everyone generally chooses fiber laser cutting machines, while in the non-metal material industry, especially in precision processing and advanced handicraft processing, everyone still chooses to use CO2 laser cutting machines.

Although the current market trend is towards fiber laser cutting machines, is fiber laser cutting machine the best choice? CO2 laser and fiber laser have different laser techniques due to their different physical characteristics. Of course, both have their strengths and weaknesses. Depending on the processing objects, each has its advantages and disadvantages.

CO2 laser is a gas beam obtained by exciting carbon dioxide molecules, and its wavelength is 10.6 μm; while fiber laser puts a crystal of Yb (ytterbium) compound as a medium in the optical fiber, and irradiates the crystal with a beam to obtain Solid laser, its wavelength is 1.08μm. The physical characteristics of different wavelengths have a great impact on the processing characteristics of the two.

The concept of fiber laser was originally recognized because it is a laser that can propagate through optical fibers. The reason why it can be propagated through optical fiber is its wavelength. It is precisely because of its wavelength of 1.08μm that it can be propagated through optical fiber. The advantage of using optical fiber for propagation is that its optical components have a long service life and high maintenance performance.

CO2 laser processing machines use reflectors to propagate laser light from the oscillator to the processing point, usually in an optical path isolated from the outside air. Although the optical path is filled with air free of ordinary dust or foreign matter, after long-term use, the surface of the reflector will be adhered to by dirt and needs to be cleaned. In addition, the reflector itself will also be worn due to the absorption of trace amounts of laser energy and needs to be replaced. In addition, to propagate laser light from the oscillator to the processing point, multiple reflectors are needed to adjust the reflection angle of the laser light for propagation, so maintaining normal operation requires certain technical capabilities and management.

However, in a fiber laser machine, the laser light is propagated through an optical fiber from the oscillator to the processing point. This optical fiber is generally called a light-guiding fiber. Since there is no need for optical components like reflectors, and the laser is propagated within the light guide fiber that is isolated from the outside air, the laser is almost not lost. However, strictly speaking, the laser propagates repeatedly around the periphery of the light guide fiber. , so the light guide fiber itself will suffer some loss, but compared with the reflector in the CO2 laser machine, its service life is several times longer. In addition, if the propagation path is above the minimum curvature of the light guide fiber, the path can be freely determined, so it is very convenient to adjust and maintain.

There are also differences between the two in the laser generation process (laser oscillator construction). A CO2 laser oscillator generates laser light by placing gas mixed with CO2 in a discharge space. In order to ensure the normal operation of the resonance length derived from the laser output power, optical components are installed inside the oscillator, and the optical components inside the oscillator need to be cleaned and replaced regularly.

The cleaning and other maintenance cycles of the CO2 laser oscillator are set at about 4,000 hours, while the fiber laser oscillator is set at about 20,000 hours. As mentioned earlier, it can be said that fiber laser processing machines have great advantages in terms of service life and maintenance performance.

In addition, we can also try to compare from the perspective of operating costs such as power consumption. The photoelectric conversion rate of CO2 laser oscillators is said to be about 10 to 15%, while that of fiber laser oscillators is about 35 to 40%. Due to the high photoelectric conversion rate, less electrical energy is converted into heat dissipation, and the fiber laser processing machine can control the power consumption of cooling devices such as coolers to be lower. Generally speaking, the oscillator of a fiber laser machine has higher precision requirements for the cooling temperature management of the oscillator than a CO2 oscillator. However, under the same laser output power, the oscillation of the fiber laser machine The cooling capacity of about 1/2 to 2/3 of the CO2 laser oscillator used in the device is sufficient. Therefore, considering the power consumption of all devices of the laser machine, the fiber laser machine can operate at about 1/3 of the power consumption of the CO2 laser machine. It can be said to be a very energy-saving laser machine.