At a Glance:
- Laser marking provides three key benefits: a high contrast, permanent marks and adaptability to complex shapes.
- Fiber lasers are effective at high-quality marking engravings on most metals, which makes them a viable option for the automotive industry.
- Laser systems can also be connected to a factory network or an iteration of IIoT, facilitating the inclusion of the traceability process into automated production lines.
Studies estimate that the global automation industry will generate around $214 billion in 2021. This is largely driven by increased adoption of process automation, 3D printing, AI and IIoT. As such, manufacturers are constantly looking for ways to optimize processes and improve product quality to offset the tight competition caused by globally linked economies and the adoption of the connected enterprise.
The advent of IIoT and the connected enterprise has also caused a spike in the importance of traceability, especially in the automotive industry.
As supply chains become increasingly complex, manufacturers must now collect more accurate data in real time and leverage automated identification systems to enable traceability. Uniquely identifying parts—from the moment they are created until the final products are shipped—makes it possible to follow them through every stage of the production while allowing for process optimization.
Not only does an effective traceability system verify the history of parts from production through to shipment, but the information it provides can also be used to identify bottlenecks and quality control issues along the supply chain.
Choosing the Right Marking Technology
A major factor in implementing a traceability system is the choice of product marking technology. Laser marking systems are a solution for manufacturers searching for high-quality marks that ensure conformity and accountability. Compared to well-known methods such as inkjet printing and pin stamping (dot peening), laser markers provide better-quality results.
They do so by providing three key benefits: a high contrast, permanent marks and adaptability to complex shapes. Innovations and configurations can be easily added to the technology to make it more amenable to new IIoT efforts.
How High-Contrast Marks are Made with Laser Technology
Many manufacturers in the automotive industry use aluminum (and its alloys) for its unbeatable strength, corrosion resistance, versatility and, most importantly, its lighter weight.
Fiber lasers are very effective at marking high-contrast engravings on anodized aluminum and on most other metals. They do so without compromising the strength, integrity and precision of the parts being marked. This makes lasers the new preferred marking system for facilitating traceability in the automotive industry.
Using fiber lasers for marking aluminum parts ensures that:
- Codes will always be legible (high contrast);
- Parts are permanently marked, no matter their shape or dimension; and
- Marks are resistant to any production line processes.
In particular, laser etching is the best way to create high-contrast markings on aluminum. It does this by modifying the surface of products at a microscopic level. During the etching process, the laser beam applies a tremendous amount of heat to the surface of the material, melting and expanding the material’s surface, and creating a texture on the microsurface that results in a color change and contrast mark.
As a result of the lasting changes to the surface texture, the marks are permanent, durable and resistant to abrasion and scratches. The barcode/text looks blackened while the background appears whitened (which enhances readability), owing to the way light is diffused from the marks.
Legibility of Codes Over Time
Manufacturing parts are often subject to repeated use, harsh operating conditions and extreme temperatures over their lifecycle. Labels made by inkjets, dot peens or other non-permanent marking methods can become defaced or illegible over time.
Due to the wide use of aluminum and aluminum alloys in the automotive industry, manufacturers need to use the best methods for aluminum engraving to guarantee lifetime traceability of their products and accessories. This will enable the marking of QR codes, data matrix codes, barcodes or serial numbers onto aluminum parts in a way that can withstand damages or changes to the surface of the material.
Aluminum products and accessories are exposed to surface treatments which can affect the legibility and durability of markings. As such, it’s important to create marks with high readability to optimize traceability and the information gathering process.
Laser etching provides lifetime traceability and legibility of markings on aluminum products by achieving:
- A maximum roughness of 5 μm on localized melted aluminum surfaces
- Zero signs of visible corrosion over time after prolonged exposure to harsh atmospheric conditions
How to Keep Legible Marks After Surface Treatments
Automotive parts such as suspension components, wheels, seat structures and engine components are exposed to sandblasting, e-coating, powder coating and other surface treatments. These treatments can affect the legibility of 2D codes.
To prevent this, manufacturers can use fiber lasers to engrave deeper codes that stay readable post-treatment. Laser parameters are adjusted to create a code that goes deeper into the material and has a rougher surface texture.
Adaptability to Different Parts and Environments
Laser marking systems have extremely flexible implementations and configurations. They can be designed to work with a stable workpiece while the laser moves (or vice-versa). In some applications, both the workpiece and laser beam are immobile while galvo mirrors move the laser beam around the material.
Laser marks also work with cylindrical workpieces. No matter the application, there’s no need for human operators to manually adjust depth or distance, even when switching between several different products with different marking parameters. This can all be programmed from the laser machine’s interface.
Laser systems can also have a 3D optical configuration that provides the largest marking range for aluminum products. This can be complemented by an autofocus system that detects part-positioning variations and automatically adjusts the marking configuration to consistently generate high-contrast markings.
This capability allows 3D heads to mark all kinds of geometries and compensate for bended parts by using a fast and precise movable lens to move the laser focus into an optimal position.
Laser systems are generally impermeable and can resist (depending on IP rating or certification) the adverse effects of harsh operating environments. Their toughness, adaptability and flexible configuration make lasers the preferred marking system for a wide range of industrial applications.
Thanks to the ongoing evolution of production processes and increasing regulatory scrutiny, ensuring traceability of automotive parts and accessories has become an important step in the supply chain.
Industrial laser markers are low-maintenance machines that are easy to automate, use no consumables and have a long operating life. They can be designed as standalone marking workstations or integrated into production lines.
To help with new IIoT efforts, laser systems can also be connected to a factory network or an iteration of the IIoT, facilitating the inclusion of the traceability process into automated production lines.
Jerome Landry is an application specialist at Laserax. Trained in physics and physical engineering, he has been working in the high-tech industry for more than four years. He has hands-on experience with laser processes and their interaction with materials, as well as with industrial traceability standards.