Do you know laser cleaning?
The laser is a very versatile tool present in many aspects of our daily lives although sometimes we are not aware. Its applications are very varied, being used for example to read bar codes in stores, to weld steel beams in the construction, or to make decorative markings on wooden boxes or glass vessels.
Before we get into what laser cleaning is, we have to take into account what laser we are going to need considering the type of material and application.
Laser types and laser selection
There are different types of lasers, which can be classified depending on their application according to their power, wavelength and pulse duration.
These three aspects are very important, since we cannot use the same power in a laser to read a barcode as to weld a steel beam, the first being very weak, of less than 1 W, and the second highly powerful being more than 1,000 W.
Similarly, we cannot use the same laser if we want to mark wood or if we want to mark glass, since, depending on the material, it will absorb a certain wavelength or another. This means that, if we use a CO2 laser with emission in the wavelength of 10,600 nm, we can easily mark wood, but to mark glass we will need an emission laser in the green wavelength of 532 nm or a laser of emission in the ultraviolet wavelength of 193 nm.
The third great point to consider is the laser pulse duration, since it determines the amount of heat that the material will accumulate and the thermally affected area. If we have a continuous laser pulse, whose pulse duration can be 1 ms, it will bring a lot of heat to the surface by providing a lot of energy for a long time and this coul cause burned or deformed areas due to the heat. If on the contrary we use an ultra-short pulse laser, for example 1 fs, then the material will evaporate from the area where we are working on in an instantaneous way so it can not transmit heat to the surrounding areas, generating a much more defined finish.
How is the laser applied to surface cleaning?
In this way, once known how a laser works, we can say how it is applied in surface cleaning. The laser is mainly used to remove layers of different materials, such as the oxide layer formed on top of a metal, or the layer of lubricant present in some component, or simply remove a layer of paint that we no longer like and we want to leave the original color of the piece.
The great interest of the laser as a cleaning method is based on the different wavelengths that the different materials absorb, as well as the power used. For example, oxides absorb infrared radiation very well, which allows them to be removed very well from metal surfaces without damaging the surface below, which almost does not absorb energy at such wavelengths. In turn, this makes it possible for us to use high powers to remove the oxide faster, as the metal underneath that remains unaltered by the action of the laser does not absorb energy. Once these two aspects are known, the pulse time of the laser can be large, because the surface below that we want to bring to light or clean, does not absorb the energy emitted by the laser, and if we want to clean large areas, we the definition of the borders will matter little.
Once you have seen all this explanation about laser cleaning, now you can understand how it works. This application has a lot of science behind it and you can get incredible results. Do you want to embark on the adventure of laser cleaning? Contact us and we will help you.
Here you can see some of the Laser Technology Projects we have carried out: