Have you ever looked at certain parts of a machine closely? If you have, then you’d have surely noticed a series of numbers and alphabets etched on its surface. Generally, this is the serial number of a certain model or a product that helps in distinguishing it from other similar products. These markings or etchings are done with the help of a laser, and the process is known as Laser Marking.
Laser Marking – What is it and How it’s Done
Laser marking is a comprehensive term that usually refers to the processes of engraving, foaming, ablation, and so much more. Laser marking is the process in which a beam of laser is used to mark a variety of surfaces, including titanium, steel, ceramic, wood, and even cardboard. These high-energy beams leave a permanent mark that is rub-fast and solvent-resistant.
Laser marking has given rise to a wide range of applications. Also, this process has several benefits that make it a very favorable process. Due to its versatility, this process is employed in numerous industries.
There are a number of methods to go about laser marking and the type and quality of the engraving decide what method is chosen. Not just text and numbers, even barcodes, QR codes, graphics, and logos are etched into products and parts of machinery with this technology.
What Happens During a Laser Marking?
To know how laser marking works, one should know the science behind lasers. LASER is an acronym that stands for Light Amplification by the Stimulated Emission of Radiation. A laser is a beam of intense monochromatic light. When a laser beam of a higher wavelength hits a surface, it marks the particular area, and one can create desired etchings on the surface.
Usually, the energy released by a laser beam is measured in wavelength, in nanometres (NM). The parts of the light spectrum each possess a different wavelength of energy – the higher the wavelength, the more powerful the laser beam tends to be. The laser beam interacts with the surface of a material and alters its properties. This alteration leads to the marking of the said surface.
As said earlier, lasers are intense and concentrated beams, which implies that they give way to remarkably precise markings and engravings. Because of their clarity and high quality, these markings are easy to read and scan, on any type of material. Also, one can be sure of the accuracy of a certain mark engraved by a laser – in the case of 2D codes like bar codes, the correctness of the code is very important.
So, to create accurate, permanent, and long-lasting markings, one opts for the process of laser marking. Now, let’s take a look at some of the methods that are involved in this process.
Various Laser Marking Methods
There are quite a number of laser marking methods one can proceed with. But, based on the application and use, the process opted differs. Annealing, engraving, and foaming are some of the most employed methods.
Generally used for marking nameplates, annealing marking is a process where a laser beam heats a surface – a metal surface, specifically. This heating leads to a structural change in the metal which, in turn, results in a color change. The laser doesn’t penetrate deep into the metal surface, so there aren’t any imperfections. Annealing marking is employed in several industries including automotive and manufacturing.
In this process, the laser beam removes some amount of the material from its surface by evaporating it. From plastics, ceramics to stone, many materials are perfectly suited to undergo this process. The marking, or engraving, in this case, is produced in the form of depressions. The evaporation of the metal takes place because of the heat – this also causes a change in color. This method is comparatively cheaper, so this is a popular form of laser marking.
Staining is a method that involves no penetration. The etching takes place because of the chemical reaction that takes place between the laser beam and the material’s surface. Because of the phenomenon of localized heating, different colors of byproducts are produced, giving you a contrast effect. Plastic marking is the best example of the staining process.
As the name suggests, during foaming, the heating of the surface of the material gives way to the emission of gas bubbles. To produce light markings that stand out well in dark-colored materials and objects, foaming proves to be a perfect choice. The marking appears a bit raised compared to the surface of the material.
When you think of laser marking in leather, carbonizing is what you should think of. When you want to make a marking that is darker than the surface, carbonizing comes in handy. With organic compounds and synthetic polymers, this method helps in breaking bonds, which leads to the release of oxygen and hydrogen. Due to this reaction, the area tends to darken.
Removing involves simply what the name of the process says – it is employed to remove a coating over the surface of a material, with the help of a concentrated laser beam. This method is also known as ablation. Metals with shiny coatings and laminations work brilliantly with this process. Removing is employed in cases of creating labels and fittings.
Applications of Laser Marking
A few years after its invention, laser marking had very limited applications, mostly cutting. But with the development of technology and science, the scope for this process has widened considerably. Below are some of the common applications of laser marking.
The etching of serial numbers and character strings into various products is one of the most common applications of the laser marking process. With this process, clear markings of any shape and size can be made on various materials.
By updating a certain design on laser marker software, one can obtain flawless and clear-cut logos and patterns on any product. Traditional methods like printing tend to be wearisome, so laser marking is preferred more these days.
A laser beam is very thin, which makes it the perfect choice for accurate and minute markings. Laser marking is employed in creating 2D codes like matrices, bar codes, QR codes, etc. Due to the increased accuracy, these codes are easy to scan.
Why Choose Laser Marking?
Compared to other marking methods, laser marking proves to be quite favorable. This method boasts several benefits over the other possible marking techniques.
- The process involves no contact between the material and the equipment, thus protecting it from any damage like abrasion.
- Methods like acid etching create harmful byproducts that ruin the environment. Laser marking has no such ill effects.
- With its lightning-fast speed, laser marking proves to be a time-saving process.
- The precision one gets with laser marking is unmatchable by any other engraving method. Also, the markings are long-lasting.
- Highly versatile, safe, and easy to use.
- Comparatively very cheap because of lower operational expenses.
Laser marking is a technology that has been adopted by several industries for countless applications. Depending on the material and the method required, different kinds of machinery are used for this process. Due to its ease of use, flexibility, durability, and high quality, this method is widely chosen over any other etching or engraving method.