Direct part marking is often required in industrial applications where traceability is mandatory because of its ability to permanently mark the surface of the parts. Such markings can be achieved with different technologies and it is not always easy to choose the right one for a specific application. Among all the industrial marking systems, dot peen marking and laser marking systems are particularly common. The following descriptions could facilitate your choice.
In order to make a judicious choice, it is important to first understand how both technologies work. This allows understanding more easily in which applications each technique is better suited and what their operation limits are.
Dot peen marking is a technique that uses a pin made out of a rigid material such as carbide in order to indent locally the part to be marked. This leaves small holes on the surface of the material that change its visual aspect and its roughness. The indentation is assured by an electromechanical system that can translate in X and Y in order to mark the desired pattern on the material.
In comparison, the phenomenon behind laser marking systems is more complex and can be explained by the fact that powerful lasers can heat certain materials. Those materials then endure chemical or mechanical modifications that change their visual aspect and create the marking. In order to sweep the laser on the whole material according to the desired pattern, the beam is reflected on two mirrors whose orientations are controlled by a computer.
Applications & Materials
Due to the technology upon which dot peening is based, it is often used for the marking of rigid materials such as metals or hard plastics. Thus, this technique is frequently found in the automotive and aeronautics industries.
However, laser marking systems can be optimized for several materials. Laser experts can control several parameters such as the wavelength and the power of the laser beam for several applications and materials. This important parametrization makes laser markers effective for various materials such as metals, ceramics, wood, plastics…
Types of markings
The use of dot peen systems is especially adequate for the writing of alphanumeric serial numbers or 2D barcodes such as data matrix codes. However, this technique is not widely used for the writing of 1D barcodes. This is explained by the fact that 1D barcode readers need a higher level of writing contrast than 2D barcodes. Such a level of contrast cannot be achieved by dot peen marking.
Laser marker systems stand out with their ability to do different types of tracking codes and markings ranging from alphanumeric serial numbers to 2D barcodes.
Performance and Costs
The main advantage of dot peen systems is their low price in comparison to other marking techniques. In fact, such systems cost between 8,000 Can$ and 15,0000 Can$. So the investment in dot peen markers is rapidly profitable. However, due to the mechanic contact between the system and the material, the writing tip deteriorates quickly and has to be replaced. This leads to important recurrent costs and the need for constant maintenance of the dot peen marking system.
The fact that the tip mechanically modifies the surface material can also be an advantage because it creates a profound permanent marking that can therefore survive to extreme storage and transport conditions. Such deep markings lead, however, to low-speed writing because the tip needs to scan the whole marking region.
The great flexibility offered by laser markers comes with a higher price tag . A typical laser marking system price starts at 35,000 Can$ and can go up to 100,000 Can$ depending on the power, the laser type and the industrial grade required for your application. Nevertheless, the use of laser marking systems is justified by these advantages:
- No use of consumables and low-level of maintenance needed
- Fast marking with enhanced resolution
- High contrast allowing all types of barcodes
- High speed
As a matter of fact, laser markers do not require additional or recurrent purchases which makes them a profitable long-term investment. Also, the resolution is fixed by the laser beam size which can be easily modified and can be really small allowing markings with lots of details. Also, even with enhanced resolution, the marking speed is still high because instead of moving the whole marking system, it is only two small mirrors that are rotated in order to sweep the laser on the whole surface.
Which technology fits your application?
Dot peen marking devices have been used for years and remain an effective solution mainly because of their low purchase price and their permanent markings. However, laser markers have become the go-to solution when a peak performance that ensures high-density, fast and easily readable markings is needed.
By the way, if you are looking to get one of these marking systems to better track your product, you might be interested in our ebook Industrial Traceability: How Barcodes Work. You can get it simply by clicking on the button below. Enjoy the reading!