15.03.2022

Surface Laser Cleaning
RUST REMOVAL / DEOXIDIZING

Industrial laser cleaning systems are most known for their rust removal capabilities. Application can be found in multiple industries as for example process & production or the heavy industry.

Our laser systems can be used to derust or deoxidize small machinery or materials which leave the warehouse rusted after being left there for several weeks or months.

Some of the main advantages of using laser cleaning as a rust removal method are the lack of chemicals that have to be used, the substrate is not damaged, very little pollution, etc.

COATING REMOVAL

A lot of our customers use the laser's coating removal capabilities prior to any welding, brazing, bonding or new coating process. In the heavy industry for example, laser cleaning is used to prepare train bodywork for a new coating. Our systems are also capable of removing the paint layer by layer, if you don't want to remove everything all at once.

The laser technique is a non-contact/non-abrasive process, no use of chemicals or blasting media are necessary , we see a reduction in waste, automation is easy and it's very safe.

RESTORATION

In the restoration process, laser cleaning has been used with satisfying results in for example stone conservation to remove encrustation. Alongside the aesthetically pleasing results, it is relevant to determine that laser cleaning does not have any adverse effects.

Compared to the more traditional techniques, laser cleaning has many additional advantages. The diameter of the laser beam can be regulated so that areas of different dimensions can be treated. There is no physical contact between the object to be cleaned and the laser equipment. This aspect can be really relevant in treating fragile materials.

NON-DESTRUCTIVE TESTING

Non-destructive testing is the technique, used in the technology industry, to evaluate the properties of a material, component or system without causing any damage to the base material. Laser cleaning can remove dirt, rust or any other contaminant from the base material, without damaging it. Because of this, laser cleaning is a perfect solution if NDT has to be performed.

SPOT REPAIR

Often not the complete surface has to be cleaned, but only certain spots on that surface. Imagine you only have to remove rust on certain spots on a weld or that you only want to clean the rivets on the body of an airplane. That's where spot repair comes in and because of the 2D-scanners in the optic of our laser systems, circles can be created at once, which speeds up the complete process drastically.

You need a clean area to apply glue or insert a spot weld? A laser cleaner might be a very good solution for your problem!

DEGREASING

Degreasing is mostly applied in the process & production industry.

It can be initiated at the end of a process line as a final cleaning solution to remove any dirt, moist or other contaminants. In the end, you're left with a clean product, ready to be sold to the customer.

Another application is the preparation of a product for a subsequent process: glueing, welding, coating, etc.

How Does Laser Cleaning Work In 5 Steps
Laser cleaning is an eco-friendly process used to remove rust, paint, oxide and other contaminants from metal surfaces. Because of its efficiency, it is being used in an increasing number of applications. Laser cleaning requires a pulsed fiber laser (typically 50 watts or more).

Traditional industrial cleaning methods are often seen as tedious (and for good reasons). Rust removal can be time and labor consuming. Oxide removal may involve hazardous chemicals specific to each material that needs to be removed. In some cases, paint removal by sandblasting can damage the metal underneath.

Dealing with these problems usually comes at a significant cost, but laser cleaning is changing this: it is a cost-effective solution that reduces cleaning times and maintenance.

If you are skeptical about these claims regarding laser technology, keep reading for the key facts about what a laser does when removing contaminants and coatings.

1. All Materials Have an Ablation Threshold

Laser ablation occurs when a material layer or a coating is removed with a laser beam. This is the process behind all laser cleaning applications. Take laser rust removal on steel. When the beam hits the surface, molecular bonds in the dust or rust layer are broken and ejected from the substrate. In less technical terms, you can imagine that the layer to be removed is simply vaporized by the laser beam.

A simple way to grasp the importance of the ablation threshold is to compare it to throwing a ball over a wall. If you don't throw it high enough, it will never make it over to the other side. Even if you throw the ball a thousand times, you will always fail. The same applies to laser derusting. You can shoot the laser beam a thousand times but as long as the energy is below the ablation threshold of the material you’re working with, nothing will ever be removed.

Now, every material has different properties and thus different molecular bonds. In other words, each material has a specific ablation threshold. To successfully remove a layer from a given material, the energy transferred by the laser beam must be above the ablation threshold of that particular material.

2. It is Possible to Remove a Material in a Highly Selective Way

Let's continue with our analogy. Imagine there was a second, higher wall behind the first one and that a ball was thrown with just enough energy to make it over the first wall, but not enough to make it over the second. The ball would bounce off the second wall and fall in between the two walls. Once again, no matter how many times you throw the ball, you will always get the same result. You will make it past the first wall but never the second.

Since there is an ablation threshold for each material, laser cleaning can discriminate between two or more materials when trying to remove an undesired layer from an object. Given a sufficiently large ablation threshold difference between the materials, it is possible to select a material to be removed (i.e., the one with the lower ablation threshold) while leaving the other material untouched.

For example, the rust ablation threshold is much lower than the threshold for common metals like steel and aluminum. The same goes for paint and oil. This vast gap between two values allows contaminants and coatings to be completely vaporized without any risk of damaging the base material underneath. There's just not enough energy for damage to happen.

3. A Strong and Short Power Burst Means Faster Removal

You can think of laser ablation as similar to carving stone with a hammer and a chisel. You can use a small hammer and do many small hits on your chisel. Or, you could just as well use a bigger hammer to leverage more power, hence reducing the required number of hits and increasing the removal speed. The idea is the same with laser cleaning, except that you only want to remove a layer of material: the contaminant.

Fiber laser cleaning systems can remove any given layer using two different methods. Either the laser beam is a continuous wave of light, or it is pulsed at a given repetition rate. Even if the result is pretty much the same, the removal speed varies a lot according to the method.

Working Principle of Fiber Laser Cutting Machine
In today’s industrial manufacturing field, CNC fiber laser cutting machines have a wide range of applications in all walks of life due to their efficient and flexible processing advantages. Especially in metal processing, fiber laser metal cutting machine has almost become a must-have tool for all processing manufacturers, and People's daily life is closely related, but most people don't know how it works. Today, Mister Laser will take you to understand the working principle of laser fibra cutting machine, so that everyone can understand it more deeply.

The principle of laser cutting

Laser cutting machine steel is to focus the laser light emitted from the laser into a high power density laser beam through the optical path system. The laser beam irradiates the surface of the workpiece to make the workpiece reach the melting point or boiling point, and the high-pressure gas coaxial with the beam blows away the molten or vaporized metal. As the relative position of the beam and the workpiece moves, the material will eventually form a slit, so as to achieve the purpose of cutting.

Advantages of fiber laser cutting

The laser cutting process uses an invisible beam to replace the traditional mechanical knife. Its working principle also determines that it has advantages that other processing methods do not have:

(1) High precision, fast speed, narrow cutting seam, minimum heat-affected zone, the smooth cutting surface without burrs.

(2) The laser cutting head does not touch the surface of the material and does not scratch the surface of the workpiece.

(3) The slit is narrow, the local deformation of the workpiece is extremely small, and there is no mechanical deformation.

(4) It can cut steel, steel, carbon steel, stainless steel, aluminum alloy plate, and other hard materials without deformation.

(5) Numerical control programming can process any plan, can cut the whole board with a large format, no need to open the mold, economical, and time-saving.

What a Fiber Laser Marking Machine Can Do For You
If you are just entering into the world of marking, you are coming in at a very opportune time.

This is because this industry has old and new technologies that together make marking a very interesting, beautiful and profitable undertaking.

And none of the technologies are as flexible and intriguing as fiber laser marking.

In this article, we are going to introduction the technology of Fiber Laser marking Machine, understand its scientific background, its applications, materials targeted and its challenges.

After reading this article, you should be able to discern how best to use this machine for your own applications.

Understanding Fiber Laser Marking

A fiber laser machine essentially has three main parts, including the pump, the resonator and the beam delivery system.

The pump comprises of laser diodes from which a light beam is emitted and transmitted through fiber optics to a resonator which contains what is known as the gain medium.

The resonator hosts the gain medium, which in simple terms is a fiber optics medium doped with rare earth elements.

The main differences between different fiber laser applications are based on the wavelengths produced, which determines the surfaces that each type can mark on.

Metal markers are mainly Ytterbium doped, giving them the wavelength that is needed for optimal absorptivity for material marking various metals and plastics.

The resonator combines the gain medium with a set of full and semi-reflecting bragg grating components, that allow for refraction, amplification and filtering light waves to get the right wavelength required for marking.

The filtered beam is then transmitted to the beam delivery system, which is simply a beam expander and a lens contained in a beam head. This is the ‘laser pen’ that does the marking

Flexibility is the main advantage of fiber laser marking, thereby making it the most preferred engraving and marking technique in the industry, due to its versatility in marking diverse materials.

The information marked can also be chosen freely, ranging from text, numbers, logos, codes, images and photos.

Color change is a common process used in Laser Marking.

The process provides high contrast labelling on any material without damaging its surface.

In this process, the laser heats the material at the precise intended areas, exciting atoms and vaporizing the required parts, thereby providing a high quality contrast color-change on the material.

surface cleaning and structuring
Laser coating removal is an ablative process whereby laser energy is focused and absorbed by the surface, resulting in vaporization of the coating with minimal effect to the underlying substrate. This process can be applied to various materials including metal, plastics, composites and glass.

Several new grades of press-hardened steels (PHS) have been developed for the body-in-white (BIW) structure in the automotive industry that combine desirable properties of strength and formability. Prior to assembling PHS components, the aluminum silicon coating must be removed to allow better weld surface capabilities. The high power pulsed lasers successfully remove the coating without affecting the mechanical properties produced by the weld bond.

Coating removal applications are also used in heavy industries such as aerospace and ship building for their cost-effective and environmental-friendly alternative to conventional abrasive and chemical processes. Because lasers operate as a non-contact surface removal application, there is no need for a secondary medium that contributes to waste streams.

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