Metal Laser Marking Best Practices

Over the last few decades, laser marking systems have steadily risen in popularity. Prized for their fast coding speeds, high accuracy, and minimal maintenance factors, laser marking systems are common fixtures in food packaging plants, pharmaceutical development facilities, aerospace part factories, and other industrial manufacturing/packaging operations. 

Companies seek out laser marking systems to complete highly demanding code applications. For instance, high-volume beverage packaging facilities rely on laser systems to place traceable markings on tens of thousands of products daily. In another example, automotive part makers use laser systems to permanently mark components with component information and traceable data.

Today, one of the most frequent laser applications is metal marking. From coding stainless steel auto parts to aluminum cans, laser systems are particularly well-suited for industrial metal marking because:

• Laser markings are extremely durable.
• Laser systems offer stationary print ability, fast coding speeds (an option for machine shops with high volume parts but not an automated production line), and industry-leading accuracy.
• Laser systems are compatible with traditionally challenging substrate shapes.

Of course, metal laser marking will only succeed if one follows proper coding protocol and utilizes the right equipment for the job. If you’re looking to enter the world of laser marking, follow these best practices for excellent results.

Use a Fiber Laser System

Today’s marketplace is filled with different laser coding technologies, including UV laser, CO2 laser, and fiber laser systems. For metal coding purposes, fiber laser is the optimal choice. Why? It largely comes down to wavelengths. 

When looking at laser system specifications, you may notice a system is identified by how long the wavelengths are. For example, most UV laser systems work with wavelengths around 355 nm, emitting laser energy in the UV spectrum of light; however, there are power limitations to UV laser systems starting at two watts and going up to 10 watts. Fiber laser systems, like InkJet, Inc.’s F8100F, emit wavelengths around 1,070 nm—a size three times longer than UV lasers and outside of the visible light spectrum. This wavelength is achieved by pulsing photons through an ytterbium-lined fiber optic cable; hence, the name “fiber” laser. The output power for a fiber laser varies and starts at 20-watt outputs and increases from there.  

With different wavelengths and power combinations, laser systems can have vastly different reactions with different substrates. Fiber laser beams are essential for creating sharp markings on hard materials such as metal and dense plastics with varying mark types. Metal engraving and annealing is typical on metals, while ablation and color changes occur on plastics. Fiber laser’s frequency output has the ability to create deep, long-lasting marks if needed. Conversely, UV laser beams are better suited for heat-sensitive materials such as thin films or changing surface colors on HDPE materials. UV lasers don’t engrave but rather create a color change or annealing effect on the surface of materials that they react with. 

To ensure that your metal markings are sharp, readable, and durable enough for long-term service, use a fiber laser marking system that is up to the task.

Find Balance Between Speed and Power

Laser systems are known for their versatility. Not only can they mark a variety of metals but can create different types of markings. These marking processes include:

• Ablation- vaporizing small material layers off of the substrate’s surface
• Annealing- using high temperatures to create high-contrast oxidized markings
• Engraving- creating cone-shaped indentations with low-frequency laser beams
• Foaming- melting material surfaces to produce gas bubbles. Once the surface cools, the trapped bubbles elevate the code for a “stand-out” result

Each of these processes is valuable for different reasons. For example, annealing is ideal for codes that require high contrast (e.g., machine-scannable codes) while engraving is optimal for markings that require top-notch durability. To create the best quality codes, it’s important to consider the pros and cons of each marking method.

Once you have determined which marking method is right for your needs, review the speed and power settings associated with it. To use the same examples as above, annealing is performed at slow speeds with low-frequency beams while engraving is completed at moderate speeds with low-frequency beams. Along with these generalizations, it’s important to consider other factors like:

• Facility environmental factors
• Specific metal type
• Output needs
• Line setup

For best results, speak with an expert about how to accommodate these different elements and create a reliable laser marking process. 

Regularly Clean Your System and Check Its Track

Preventative maintenance is an essential part of the laser marking process. Although laser systems have fewer maintenance needs than continuous inkjet or thermal inkjet printers, regular care is still required to keep laser systems operating at a high level.

On a basic level, daily cleaning and a simple part inspection will help prevent day-to-day marking errors. While the machine is off, inspect these parts for cleanliness and any signs of damage.

• The torch and its attached cables, nozzle, and protective window. If these parts are dirty, use a lint-free rag and isopropyl alcohol to wipe off any debris.
• Drive system. The drive system powers the torch and allows the laser machine to create accurate cuts. By regularly cleaning the drive system’s belts and bellows, you can extend the life of your hardware and prevent miscoding.
• Slats. Laser tables quickly fill up with scraps and grime. Cleaning your slat throughout the day creates a safe environment and leads to better code results.

In addition to cleaning these components, inspect the machine’s track to ensure that it is straight and even. If it isn’t, tighten any loose screws or bolts and check the tightness of the belt. 

By periodically performing these simple steps, you can keep your laser system running at a high level indefinitely.

Have More Questions About Metal Laser Marking? InkJet, Inc. Has Answers

When it comes to metal marking technology, it’s hard to beat fiber lasers. Fast, accurate, and capable of delivering high-quality results consistently, fiber laser systems are ideal for today's toughest metal marking applications. 

Here at InkJet, Inc., we have been helping companies complete challenging code applications for over 30 years. From fiber laser systems to high-speed printing equipment, InkJet, Inc. has everything you need to maximize efficiency and comply with coding standards. Contact us today to learn about our different laser options. 

For more metal laser marking best practices, contact InkJet, Inc. online or call 1(800) 280-3245.