Laser engraving

The technology that allows permanent images on surfaces

Laser engraving is one of the most wonderful and successful techniques that we find nowadays when we talk about drawing images on surfaces, but to have a fully knowledge of this way of “putting” permanent images over a surface we have to define what the process of laser engraving involves. This definition is far from difficult, we understand by laser graving, the use of laser to mark or engrave an object; sometimes the word etching is used to describe this method but the term is incorrect, since “etching” involves the use of substances like acid to perform the mark. Laser engraving is supposed to be complex and many times, technical, most of the times is a computer system which does the work, the system is used to control and drive the laser head and its cycles.

laser engraving machines look quite as copy machines

Laser engraved gifts

Laser engraving machines

Despite this complex disadvantage, laser engraving machines gave us as results, clean engravings in a high rates. This method doesn’t involve elements like tool bits, these one, in general, are in charge of uniting the engraving surface and the wear out.
Laser engraving is a new method that came up during the 90’, and had a considerably impact in special designed materials, we use the words “special designed” since there are materials that, with the apparition of the laser, are specially designed to be used with lasers, among them we can find novel metal alloys and polymer.

As we said before, laser engraving is a process made or ran by laser machines, this kind of machines are composed by three different main parts : a controller, a laser and a surface. The laser is very similar to a pencil (the beam emitted allows us to have control over the trace of the patterns that will be marked on the surface). The controller, in most of the cases a computer, is in charge of controlling items such us direction, speed of movement, intensity and the spread of the laser that is pointed at the surface.

There are 2 types of laser engraving machines, the most usual is the type X- Y Table, here the piece to engrave remains still; meanwhile the laser moves around in Y and X directions leaving drawings of vectors. In other cases, it is the laser that keeps still as the object moves; other times the object in Y and the laser in X. The other type of laser engraving machines is designed to be used for cylindrical objects, in this case the laser traverses a correct helix helping the laser to produce the desired image. In the case that the surface we are engraving starts to vaporize during the process, what we require is to ventilate the objects by means like blowers or vacuums to remove smoke arising and noxious fumes; this is very important in order to continue with the laser engraving process. Lasers are capable to remove material in a very efficient way, since the laser beam is designed to send energy to the surface converting a high rate of the light energy into heat. The laser beam can be focused in most materials that are not reflective, such us plastic and wood. The problem here is that these kind of machines, which are very effective, may heat up very quickly, that’s why we need to elaborate cooling systems to keep the laser in an appropriate temperature; on the other hand some systems include a way to decrease the amount of heating.

But the process of laser engraving includes the engraving of different style of patterns, this task can be achieved by programming the controller choosing a particular path for the laser beam; the laser beam trace is regulated very carefully to achieve an accurate and consistent removal depth of the material. Since the laser position is known by the controller, it won’t be necessary to put or add barriers or limits to the surface to prevent the laser from making a mistake; this is the main characteristic that defines why this technique is different from older ones. As we mentioned before, there are certain materials designed or that can be used on the laser engraving process; although people thought that wood could be weak to support the heat of the laser beam, we must remember that the first ways of laser engraving forms were set on wood. In wood, the laser power that we require is less than 10 watt.

Metal items engraved by laser systems

In case of hardwoods, such us walnut, mahogany, oak and maple the laser engraving gives us excellent results. In case of Soft woods the process of engraving is different, since we need to vaporize the wood at less- consistent depths. Engraving softwoods requires lower power and quick speed of cutting. In case of fur, we must affirm that is not an engraveable material, but we can use the laser engraving process in leather, the same happened with elements such us latex rubber.