How laser cutting works

The first laser engraving machine was the one with carbon dioxide (CO2), which is still used today. Over the years, new laser cutting techniques have been created to be able to operate on different types of materials.

To date, laser cutting is one of the most widely used techniques because it allows you to work on a wide range of materials, in a short time and at limited costs. Moreover, thanks to the precision of the laser, it is possible to customise and replicate the pieces quickly, even in large quantities and series.

Let's see together how the laser cutting technique works and on which materials it can be used.

How the laser cutting machine works

In the case of CO2 laser cutting, the beam is composed of infrared and is powered by the gas mainly consisting of CO2, nitrogen and a minimum part of hydrogen, xenon and helium.

The composition of the radius may vary depending on the settings of the machine and the material to be cut. 

In general, when we talk about laser cutting we are talking about a highly versatile technique and therefore used by various sectors, whether they are companies or artisans. 

For this reason, they are often CNC (Computer Numerical Controlled) machines, i.e. machines controlled by a computer.

The workflow for laser cutting requires a few steps and guarantees precise and quality processing. 

1. Processing of the digital file (raster or vector file);
2. Sending the paper to the machine and setting the laser settings depending on the material you want to work on;
3. Monitoring of the machine during processing;
4. Cleaning the machine once the work is finished to avoid having foreign material in the next project. 

This work process is the same for all laser machines, whether they are desktop machines (cheap countertop machines) or professional machines (dedicated to industrial production). Obviously, the power of the laser and some technical characteristics are different. For example, you can have greater or lesser processing versatility depending on the available machine.

Despite the different technologies and types, laser machines all have the same operation and main characteristics:

• The laser resonator activates the laser to cut the material, which through a beam of light and a system of lenses and mirrors focuses on the material and cuts it.

• The machine will follow the lines based on the size and thickness indicated by the design file, going to cut or drill according to the edges and methods indicated by the digital file.

• For all processes there are three important parameters to take into account: mirrors and lenses are used for the direction of the beam and to vary the power of the laser. It is also important to know that the beam operates by pulsed light and the frequency speed affects the power of the laser. 

These parameters must be set depending on the material used. For example, if you cut a particularly hard material, the power of the laser will have to be greater, however if the material is soft and the power is too high the laser could burn the material rather than cutting it.

In addition, as regards speed, it must be borne in mind that the greater the thickness of the material and the lower the speed could be. In fact, the laser head, moving too fast, could go to engrave but not to cut the material perfectly in case of high thickness. 

For these reasons, it is necessary to inquire about the composition of the material and its characteristics, in order to guarantee a project of quality and precision.

• The processing of laser cutting takes place without contact, this allows less wear of the pieces and a reduction in maintenance costs. 

Materials suitable for laser cutting

As anticipated, laser cutting can be performed on a wide range of materials. 

Among the most common are wood and derivatives, paper and cardboard, plexiglass, PMMA and other plastic materials, leather and natural fabrics.

Be careful to check the composition of the material and its properties. In some cases, dangerous gases and dust may develop during laser cutting. Therefore, having a ventilation system, carefully monitoring the processing and having a deep understanding of the various materials is essential for the safety of people and the project.

Conclusions

In general, laser cutting is a widely used technique that guarantees excellent results with limited costs. In addition, the speed of execution, the limited maintenance costs and its versatility make this technique one of the most used both in the production sectors and by hobbyists. 

Although the processing follows a simple and easy-to-learn process (especially for the cheapest machines), it is still necessary to know the materials and their composition, in order to be able to work correctly and safely.