What is the Laser Cutting Process?

Some of the benefits of choosing laser cutting over more traditional options include:

Easy automation. Laser cutting processes fit well into automated production lines.

Complexity. Laser cutters can create highly intricate geometries quickly.

Accuracy. Lasers cut sharp, precise edges and create extremely accurate profiles.

Finish. Laser-cut edges often don’t require any additional finishing operations.

Versatility. Laser cutting works with a broad range of metals and non-metals, wood, and thermoplastics.

How Does Laser Cutting Work?

In laser cutting, the cutting head mounts to a mobile mechanical system that provides a high degree of precision movement. The laser beam exits the cutting head through a nozzle and melts through the workpiece at the point of contact to create highly precise and clean cuts.

Laser cutters can be used to drill holes or carve shapes and angles into a workpiece. There are multiple different types of laser cutting machines and processes. Two of the most popular options include CO2 and fiber laser cutting.

CO2 Laser Cutters

With CO2 lasers, the laser resonator generates the light in by igniting light with an electric spark in a tube, then uses a series of carefully positioned mirrors to direct the beam to the cutting head. The laser passed through a focusing lens and then out of the cutting head through the nozzle. From there, the focused laser beam hits and melts through the workpiece. A gas jet (typically nitrogen) then blows excess molten material out of way, leaving a clean cut.

CO2 lasers work best with non-reflective and low-reflective materials. Highly reflective materials will reflect most of the heat from the laser beam, which can hinder the ability of the equipment to make a cut. In a worst-case scenario, the beam may reflect back into the source and damage the cutting equipment.

Fiber

As a more recent technology, fiber lasers operate differently and more efficiently. The light is generated via a diode bank, then transmitted through fiber optic cables enhanced with rare earth elements before getting amplified and focused through the lens. This process results in a significantly more powerful laser beam.

With the more powerful laser, fiber laser cutters can create enough heat against reflective surfaces to facilitate cutting. Fiber laser cutters have made it possible to laser-cut reflective materials such as aluminum, copper, galvanized steel, and more.

What are the Steps in the Laser Cutting Process?

There are three key steps governing the laser cutting process:

Step 1: Material Selection

The properties of the workpiece material will influence the choice of cutting method. Along with factors like price and visual appeal, it’s important to consider reflectivity, which determines the appropriate type of laser cutting equipment. Also consider the thickness of the workpiece. While the maximum thickness varies based on the specific equipment and material, laser cutters generally can’t cut extremely thick metal workpieces. Maximum thickness limits raise significantly with wood, plastics, and other non-metals.

Step 2: Design

CNC laser cutting machines can follow instructions derived from digital design files to direct spindles or attachments on the X or Y axis of the machine. As a largely automated process, CNC laser cutting can reproduce cuts across workpieces in a production run with a high rate of accuracy and repeatability. Engineers can also control the power of the laser to account for changes in depth, to increase cutting speed, and to moderate cut quality.

Step 3: Laser Settings

There are four settings that operators should keep in mind as they set up the laser cutting machine:

Laser power. High-power lasers can cut through workpieces and complete products faster than low-power lasers, but they also consume more power and drive up production costs.

Wavelength. The wavelength helps determine the extent to which a laser beam can heat up, melt through, and cut workpieces.

Beam mode. The beam mode measures the intensity of the beam and the diameter of the laser’s focal spot. Both factors affect the precision and quality of the cut.

Focal spot. Focal spots can vary in size and alignment. Diffuse spots or misaligned spots will create lower-quality cuts.