What are the features of laser coding?
This question inevitably concerns all those looking for a coding solution. That's why we asked our laser experts what is typical for laser codings. The answers can be summarized as follows: Laser codings are durable, high-contrast and perfectly legible, precise and gentle on materials. But what does that mean? We took a close look at these qualities.
1. Durability
Markings that are applied with a laser are highly durable. They are referred to as "permanent" or "resistant". But why?
Whether in automotive engineering, medical technology or electronics industry, almost all products and components must be marked before they run through further processing steps, are installed or used by the end customer. Most products are exposed to various influences during their life cycle – either during the production process, on the way to their final destination, or during usage.
Be it further processing steps such as cleaning, passivation or sterilization or mechanical impacts, for example during production or in use: With the right laser parameters, laser codings withstand all these influences and the most challenging environmental conditions. Laser markings are not only abrasion-resistant, but also scratch-resistant, corrosion-free and do not fade.
2. Contrast and legibility
At the latest since nearly all industrial products and components must be seamlessly traceable, reliable legibility is crucial in industrial part marking.
However, not only 1D/2D codes, but also logos, characters and serial numbers should be sharp and high contrast. Lasers are able to achieve the optimum contrast for various contents on almost any material. Which processes and laser types are suited, depends on the material and requirements.
If, for example, a deep black, non-reflective marking is required, an ultrashort pulse laser such as the F.0100-ir is usually the best choice. This laser uses pulses in the femto- and picosecond range to mark in a particularly gentle manner. That is why this marking laser is preferred for sensitive products and materials, e.g. in medical technology and for electronic components.
For complex or rough surface structures, such as on automotive castings (see picture on the right), the black-and-white marking process is an ideal solution for achieving high contrast to ensure reliable machine readability. The image above on the right shows the optimum code readability using the black-and-white marking method (see code on the left) and, in contrast, a code that was marked without using this method which is significantly more difficult to read (see code on the right).
As these two examples demonstrate, various criteria must be considered to achieve reliable legibility. Sample markings help to determine the best laser type and the most suitable process: Laser experts verify the optimum parameters directly on the products in application laboratories and adjust all factors that affect the marking result.
3. Precision
Precision in marking plays a decisive role in almost all industries. For example, in medical technology as a part of the strict regulations of the UDI directive, or in the automotive industry, where high cycle times and at the same time highest quality with minimal tolerances are requested. Laser coded content is not only crystal clear but can also be placed reliably and precisely in the smallest spaces.
Vision systems which are integrated directly into the marking laser provide automated correct mark placement: They "look" directly at the product with the laser beam and offer automatic, repeatable laser coding. In addition, a laser-integrated vision system ensures a stable and reliable marking process through further features such as inspection steps before and after marking, optical character verification (OCV) and code reading functions. This holistic process ("HELP") creates a highly efficient and economical marking process, as scrap is significantly reduced by preventing marking errors.
4. Gentle to the material
Marking lasers are all-rounders for almost all applications in industrial part marking. Depending on the laser type and the material, a variety of marking effects can be achieved by using different laser coding processes: From annealing through color change to material removal.
Especially for delicate materials or sensitive products, lasers are the first choice for marking. Lasers coding is extremely gently so that, for example, sensitive electronic parts are protected, the biocompatibility of medical products is maintained and corrosion is prevented.
The following examples of the wide range of applications on sensitive materials show how gentle and at the same time powerful marking lasers are and how flexibly they can be used for laser coding:
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Highly sensitive plastic can be photochemically colored with UV lasers without damaging the surface.
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Ultrashort pulse lasers mark with a high pulse energy and very short pulses at the same time, so that the heat input is extremely low: For example, it is optimally suited for laser coding medical stainless steel and titanium in deepest black in a material-friendly way.
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The "green laser" is also known for its strength in marking challenging materials. With a wavelength of 532 nm, it closes the gap between UV and fiber laser markers and enables the marking of materials that do not optimally absorb other wavelengths, for example white and transparent plastics, special plastics such as UHMWPE, HDPE or PMMA and highly reflective metals or material combinations.
Summary: High-quality, reliably traceable, cost-efficient
Marking lasers are a reliable and economical solution for industrial part marking: Laser codings are durable, high-contrast and reliably readable - both by machine and with the human eye. This combination ensures an important aspect in everyday production: complete traceability over the entire product life cycle. A vision system which is integrated into the marking head, enables high-precision, automated marking alignment and ensures reliable, efficient processes for all aspects of marking.
With their long lifetime and the fact that they do not require consumables, the TCO (Total Cost of Ownership) of marking lasers is low compared to other marking processes. Their compact design and an advanced laser marking software that is compatible with common industrial communication protocols, make the integration of marking lasers simple and smooth.
Further information
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