What is laser marking?
Laser marking is the process of directly marking the surface of a part with a focused beam of light. The result is a permanent mark that will not fade over time.
Laser marking technology has no limits. You can use it for marking all kinds of materials and surfaces. To achieve the best results, you must first choose the ideal laser for your material. CO2 lasers and fibre lasers are the most commonly used types of lasers. You can also modify the maximum laser power for high-speed marking.
To deliver better results, different laser marking processes can be optimized for specific applications. The two most common processes are lettering and laser engraving. Another application of laser marking is laser tempering. It is the only viable method for engraving stainless steel.
What is laser marking used for?
Laser marking is an emerging technology used in a growing number of applications. This is not surprising as it is a low-maintenance technology. It is contactless, has no moving parts, and uses non-consumables. In automated applications for production lines, personnel is not needed to operate these laser machines, and they are rarely needed to maintain them.
Laser marking is often used to implement traceability, quality control, and process improvement. By identifying each part at the beginning of a production line, barcode readers can be used to scan identifiers at each manufacturing step. For traceability purposes, it enables the tracking and tracing of parts from the beginning to the end of the manufacturing process. For quality control and process improvement, it allows you to store important and specific information for each part in a database. The most common forms of part identification are Data Matrix Codes, QR Codes, and Alphanumeric Serial Numbers.
The main industries that need engraving solutions are the automotive, primary metals (including aluminium, steel, zinc, lead, and copper), extrusion, manufacturing, and converting industries.
How does laser marking work?
To generate a laser beam that can mark the surface of a material, light is amplified by stimulating photons. The material is first charged with energy, and its electrons release that energy in the form of light (or photons). The light is then amplified. As the photons naturally stimulate the material’s atoms, their electrons release more and more photons. This creates a concentrated beam of light known as a laser beam.
To mark the surface, mirrors are used to direct the laser beam in a single direction. This creates a high contrast, high-quality marks when the beam strikes the material surface. By using different laser engraving processes, it is possible to create a mark just on the surface, deep within the material, or below the surface. It is also possible to create a mark by removing a coating (such as paint) from the surface.
How are lasers different from each other?
To understand how lasers differ from one another, one must first understand how wavelengths interact with materials. Is that how it works:
At the laser source, there is a material whose atoms release energy in the form of light. This material determines what wavelength your laser produces. For example, some solid-state lasers use Nd: YAG crystals to produce light. These crystals release a wavelength of 1,064 nanometers (or 1,064 microns).
Since different materials absorb wavelengths differently, one needs different types of lasers for different materials. For example, it is better to use fiber lasers for marking metals and CO2 lasers for marking organic materials (such as plastics and rubber).
Different lasers can also release that energy differently. One can use a continuous wave laser or a pulsed laser. While continuous-wave lasers continuously emit the laser beam, pulsed lasers release the beam at a set rate. Pulsed lasers can achieve higher peak energy density because they charge energy before releasing it. They are ideal for laser engraving applications because they are the ones that best offer high-speed marking. Continuous lasers are more suited to other laser technology, such as laser cutting, welding, and drilling.
What are the benefits of laser marking?
Laser is becoming the new standard for most marking applications. Although it represents a higher initial investment than its alternatives, it provides a better return on investment, as well as other unique benefits.
- In most cases, this is the highest speed marking solution. terms of aluminum etching performance, it is possible to create a high resolution data matrix code in just 1.40 seconds.
- Laser safety is regulated by strict international standards. Based on the laser safety class of your laser machine, you can easily tell if it is safely integrated according to your standards. For example, if you have a class 1 laser marking machine, you do not need to implement any additional laser safety measures.
- Laser marking is a traceability solution like no other. It offers almost perfect readability levels thanks to the high precision of the laser systems and the high resolution of the marked identifiers. You can also create marks that are truly permanent, capable of withstanding almost any surface treatment, including e-coating, heat treating, and shot blasting.
- It can be used to create permanent marks on materials whose surface cannot be marked directly (such as stainless steel) by creating a mark below the surface.
There are many other benefits to laser engraving, specific to each application.