The technique of laser engraving allows for etching out designs, shapes, etc., on a variety of surfaces. Metals, plastic, wood, and even jewelry can be engraved with laser beams. The excimer laser is commonly used for the purpose of engraving. The technology of laser engraving was first used in the 1970s. Today, the Nd:YAG laser is commonly used to engrave metal surfaces. In case of other surfaces like wood, plastic, rubber, etc., a CO2 laser is of common usage. The laser engraving system and engraving services have been used for creating artworks and also in industrial applications.
Laser Engraving Technology
The different components of a laser machine which carry out the task of engraving are a controller, laser beam, and a suitable surface. There are two types of laser machines, one in which the laser optics move over the surface and the second in which the surface itself moves while the laser optics remain stationary. The movement of either the laser or the surface in these machines takes place along the X and Y axes. Some of the laser machines have both the laser beam and surface moving along the X and Y axes, respectively.
Movement of laser optics is programmed by a controller. It is possible to control the speed of the laser beam's movement, intensity, direction, etc. with the help of a controller. The pattern or design of engraving can therefore be programmed into the machine. The trace of the pattern to be drawn is programmed in such a manner that it doesn't overlap. Therefore, the engraving doesn't take place twice on the same path; a crisscross pattern is thus avoided.
Ablation is the process in which a particular surface is eroded by chipping, vaporization, etc. This is not a type of burning which corrodes a surface. The laser ablation process causes the material being engraved to actually vaporize. This vaporization takes place as a result of the action of high intensity energy pulse. The amount of heat produced during the process of engraving is minimal. The laser pulse is very short and causes instantaneous evaporation of the surface being engraved. It is the reason why very less heat is produced. Finally, a finishing material is applied to the engraved surface. It prevents the surface of metal from getting corroded and keeps it intact.
Sub-surface Laser Engraving
In this form of laser engraving, the work of engraving is done at the base of a solid material. The material used for such kind of laser engraving is generally glass. The cost of operation of sub-surface laser engraving is much greater than the normal process of engraving. The high cost is attributed to expensive cooling process. Nowadays, sub-surface laser engraving is used in the creation of 3D images, mostly in crystals.
Applications of Laser Engraving
Laser engraving is mainly used to create artworks. In most cases, wood is the material being used for this purpose. It is difficult to engrave wooden surfaces due to the inconsistencies present on the surface. A type of wood that contains a high amount of resin is considered ideal for resin engraving. The other qualities needed for engraving are a light color and a surface that is not coarse.
Laser engraving technology is used not only for creating artworks, but also has industrial applications. This technology was used in industrial applications since the 1970s. The CO2 laser was first introduced in this period. The earlier methods of using chemicals and photography for creating a print-ready surface, were replaced with laser engraving.
Using a laser engraving technique is highly advantageous, since it proves to be efficient and doesn't cause any wear and tear of the tools used for engraving. Moreover, the surface used for engraving also is least affected. Overall, the technique of laser engraving is effective for decorating a variety of materials and surfaces.