Laser cleaning is an eco-friendly process for removing rust, paint, oxides and other contaminants from metal surfaces. Due to its high efficiency, it is being used in many applications. Laser cleaning requires a pulsed fiber laser.
Traditional industrial cleaning methods are often cumbersome. Rust removal can be time-consuming and labor-intensive. The removal of oxides may involve hazardous chemicals specific to the substrate. In some cases, removing paint by sandblasting can damage the metal underneath.
Dealing with these problems is often costly, but laser cleaning is changing that: it is a cost-effective solution that reduces cleaning time and maintenance.
If you’re sceptical about these claims about laser technology, read on for key facts about lasers when it comes to removing contaminants and coatings.
All Materials Have an Ablation Threshold
Laser ablation is removing a layer or coating of material using a laser beam. All laser cleaning applications are based on this approach. Take laser descaling of steel as an example. When the beam contacts the dust or rust layer, the molecular connections are disrupted, and the material is ejected from the substrate.
In less technical words, the laser beam vaporizes the layer that must be removed.
Every substance now has its own set of qualities and its own set of molecular bonds.
To put it another way, each material has its ablation threshold.
The laser beam must supply energy above the ablation threshold for that particular material to remove a layer from that material properly.
Removing Material in Highly Selective Manner
Imagine a second, higher wall behind the first wall, and a ball is thrown with just enough energy to go over the first wall but not enough to go over the second wall. The ball will bounce off the second wall and land in the gap between them.
You will obtain the same result regardless of how many times you throw the ball. You will go over the first wall but never over the second wall.
Because each material has an ablation threshold, laser cleaning may distinguish between two or more materials when removing an unwanted layer from an object.
It is possible to select the material to be removed (i.e., the material with the lower ablation threshold) without touching the other materials if there is a large enough difference in ablation threshold between them.
For example, the ablation threshold for rust is much lower than that of common metals such as steel and aluminum. The same is true for paints and oils. The large gap between these two values allows contaminants and coatings to be completely vaporized without any risk of damage to the underlying material below. There isn’t enough energy for the damage to occur.
Powerful and Short Power Bursts Mean Faster Removal
Imagine carving a stone with a hammer and chisel, and that’s how laser ablation works. You can use a small hammer and make many small taps on your chisel. Or, you can use a larger hammer to pry with more force, reducing the number of taps required and increasing removal speed. The idea of laser cleaning is the same, except you only want to remove one layer of material: the contaminant.
Using two separate approaches, fiber laser cleaning devices may remove any given layer.
The laser beam might be a continuous wave of light or a series of pulses with a predetermined recurrence rate. Even if the results are essentially the same, the removal speed can vary greatly depending on the method.
Increasing the power for a given surface area by putting the same energy into a brief pulse. This is like using a larger hammer. A pulsed laser beam is more effective than a continuous beam, providing faster removal. And short laser pulses clean the surface faster while ensuring that the underlying material does not heat up too much.
It Requires No Consumables and is Environmentally Friendly
This cleaning procedure requires almost no consumables because it merely uses a laser beam to melt the layer to be removed. That’s the beauty of the laser; it only needs a power plug to be set up and ready to use.
Furthermore, no chemical compounds or solvents are used in the laser.
As a result, laser surface cleaning is one of the safest rust removal and coating methods. No chemical waste must be disposed of, but employees are completely safe when working near laser cleaning machines designed to meet international laser safety standards. Employees don’t need personal protective equipment or deal with those nasty chemicals.
Since laser cleaning evaporates material into fumes, you should install a fume extraction system near the laser machine to ensure that no paint, oil or dust particles are released into the air.
Laser Cleaning Makes Sense in a Variety of Industrial Applications
Industrial laser cleaning can clean burnt rubber residue from tire molds, repurpose old pipes, clean pipes in nuclear power plants, and even larger operations like removing paint off deteriorated bridges and prepping welded surfaces.
This non-contact cleaning technology can be used in a myriad of industrial applications. The only limitation is distinguishing between the material to be removed and the material to be protected.
Currently, the most common laser cleaning applications include:
- Pre-welding treatment to remove rust and other contaminants from welded areas
- Post-weld treatment to remove oxides from aluminum and stainless steel
- Laser surface treatment to maximize paint adhesion
- Oxides are laser-removed from specific alloy ingots.
- Coating removal after the painting process to replace part coverings on the production line
- Removal of parts that have been scrapped due to paint defects
Laser ablation is also used in a wide range of other industrial applications in addition to cleaning.
In Summary
Many challenges in rust removal and other industrial cleaning applications can be solved with laser cleaning solutions.
Fiber lasers provide a quick and permanent solution for many sectors by picking the precise substance to be removed.
