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Laser cutting

technology Maturity 7-9 Next article →

Laser cutting is an industrial technology that uses a concentrated beam of light to vaporize or melt materials. This process creates precise edges in a wide variety of substances. While once limited to specialized factories, laser cutting is now common in schools, small businesses, and architecture.

This technology is valued because it offers high precision and reduces material contamination. Unlike mechanical tools, a laser beam does not wear down during use. This allows for consistent accuracy throughout the entire cutting process.

The mechanism of laser cutting relies on high-power light and computer guidance. A system called Computer Numerical Control, or CNC, directs the laser beam. The machine follows a specific pattern known as G-code.

Laser-and-CNC-Control
Laser-and-CNC-Control

Before the main cut begins, the machine must perform a pierce. This involves using a high-power pulsed beam to create a starting hole. For stainless steel, this piercing process can take between 5 and 15 seconds. Once the hole is made, a lens focuses the laser into a tiny, intense spot. Depending on the material, the beam causes the surface to melt, burn, or vaporize. Often, a jet of gas is used to blow the molten material away from the edge. This leaves a high-quality surface finish on the workpiece.

Laser cutting CAD and physical part
Laser cutting CAD and physical part

There are several distinct methods used to cut different materials. Vaporization cutting is often used for non-melting materials like wood, carbon, or certain plastics. In this method, the beam heats the surface to a flashpoint to create a keyhole. As the material boils, the resulting vapor erodes the walls to enlarge the hole. Another method is melt and blow, or fusion cutting, which is common for metals. This process heats the material to its melting point and uses high-pressure gas to blow the molten bits out. For brittle materials like glass, engineers use thermal stress cracking. The laser causes localized heating and expansion, which creates a crack that can be guided along a path.

CNC Laser Cutting Machine
CNC Laser Cutting Machine

Different types of lasers serve different industrial needs. CO2 lasers use a gas mixture, such as carbon dioxide, helium, and nitrogen. These can be excited by passing a direct current (DC) through the gas or by using radio frequency (RF) energy. RF methods are becoming more popular because they use external electrodes. This prevents the erosion and plating issues found in DC designs. Another major type is the fiber laser, which is a solid-state laser. Instead of gas, it uses a solid gain medium and amplifies the beam within a glass fiber. Fiber lasers are highly efficient and can process reflective metals like copper and brass. They also produce an extremely small spot size, which can be 100 times smaller than a CO2 laser spot.

Industrial 4kW laser with flying optics system
Industrial 4kW laser with flying optics system

The history of this technology shows rapid advancement. The first production laser cutting machine was created in 1965 by the Western Electric Engineering Research Center. It was used to drill holes in diamond dies. In 1967, British researchers pioneered laser-assisted oxygen jet cutting for metals. By the early 1970s, the technology was used to cut titanium for the aerospace industry. At that time, CO2 lasers were primarily used for non-metals like textiles. This was because early CO2 lasers lacked the power to overcome the thermal conductivity of metals.

Laser cutting offers significant advantages in terms of precision and scale. Modern industrial lasers can reach power ratings of 6000 watts. This is a large increase from early machines that were rated at 1500 watts. Higher power allows lasers to approach the thickness capabilities of plasma cutting machines. However, the capital cost for these high-power lasers is much higher than plasma systems. In terms of accuracy, laser cutters can achieve a positioning accuracy of 10 micrometers. They also demonstrate high repeatability of 5 micrometers. This precision allows for tolerances as close as 0.001 inch.

Dual Pallet Flying Optics Laser
Dual Pallet Flying Optics Laser

Industrial machines are organized into three main configurations based on how they move. Moving material lasers keep the cutting head stationary and move the workpiece underneath. This method is often the slowest but requires fewer optics. Hybrid lasers use a table that moves in one axis, typically the X-axis, while the head moves along the Y-axis. This provides a more constant beam path and can reduce power loss. Finally, flying optics lasers feature a stationary table and a moving laser head. This configuration allows the beam to move across the material to perform the cut.

Industrial 4kW laser with flying optics system
Industrial 4kW laser with flying optics system
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🖼️ Images & Media (7)
File:LaserCutter.jpg
LaserCutter.jpg
Lasercutting-video.ogg
File:Laser cutting CAD and physical part.png
Laser cutting CAD and physical part.png
File:Laser-and-CNC-Control.jpg
Laser-and-CNC-Control.jpg
File:CNC Laser Cutting Machine.jpg
CNC Laser Cutting Machine.jpg
File:Dual Pallet Flying Optics Laser.jpg
Dual Pallet Flying Optics Laser.jpg
File:Industrial 4kW laser with flying optics system.jpg
Industrial 4kW laser with flying optics system.jpg
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