Laser engraving is a special type of laser marking, which produces similar results compared to traditional engraving methods, but using inks or bits that come in contact with the surface material.
In laser marking, a low-power laser beam moves slowly over the target material. The beam lightly discolors the material, creating permanent markings with high contrast, without damaging or compromising the structural integrity of the material. Laser marking is also called laser coloring or dark laser marking, indicating the fact that the material is not affected by the marking.
However, laser engraving uses a high-power beam to vaporize the surface of the target material, leaving a cavity whose depth can vary. Laser engraving works on several materials, including plastic, wood, anodized aluminum, stainless steel and glass surfaces.
Laser engraving is especially useful for marking parts that will be used extensively, because the deep penetration of the laser in the engraving process ensures permanent marking.
How does laser engraving work?
Laser engraving can be achieved with a special industrial machine. Laser machines vary significantly depending on the options they are provided with. Thus, there are CO2 laser engraving machines that emit primarily low-power laser beams.
There are also high-power fiber laser machines, specially designed for volume engraving, in an industrial setting. Then, the machines vary depending on the specific chemistry they use to create the laser beam.
However, all laser cutting and engraving machines have three common components:
- the laser itself
- the laser control system
- the marking surface
Apart from these, the machine operator uses special software to change the settings of the cutting or engraving device. The laser is aimed at the surface of the material. These settings can be used to change the laser work application. A picture chosen for engraving on a certain material must be produced by a graphic editing software (Adobe Illustrator, Inkscape, Adobe Photoshop, AutoCAD – these can produce vectorial files).
These vectorial files have a special property that makes them ideal for laser engraving application. Images in vector files retain their clarity and proportions when adjusted to any size.
Thus, a saved vectorial file containing the desired image can be loaded into the software of the laser engraving machine and translated into numerical data. The engraver’s own program can retrieve this data and use it to program the laser machine’s control device to produce the supplied image using the laser.
From a conceptual perspective, we can think of laser engraving machines as similar to 3D printers. Both machines use digital models to automate a creative process.
However, while a 3D printer works by printing plastic blocks into the programmed model, the laser engraving machine uses a programmed model to remove something from the material – leaving an engraved text or image on the surface.