Invented by Elias Snitzer in 1961, fiber laser machines have come a long way in the last 60 years. Known as one of the most powerful and efficient marking technologies available today, fiber laser systems are found throughout the packaging and manufacturing industry. 

Particularly adept at cutting and marking metal materials, fiber laser systems play a key role in helping companies produce and trace their products. For example:

• Aerospace and automotive manufacturers commonly utilize fiber lasers to place permanent traceable markings on their parts and products. 
• Food and beverage co-packers use fiber laser systems to mark industrial quantities of cans, bottles, and other packaging.
• Pharmaceutical and medical device developers use fiber lasers to create permanent, high-contrast markings directly onto products and product packaging.

In these cases and others, fiber laser users depend on their systems to create durable, machine-scannable codes and markings. Not only are these markings key to maintaining full product traceability, but they are also often required by regulatory agencies such as the FDA and USDA. As such, companies must keep their laser systems in proper working order to avoid costly production delays and/or regulatory violations. 

Of course, operating issues are inevitable with any marking system, and fiber lasers are no different. Read below to learn about the two most common fiber laser marking problems and their solutions.

The Two Most Common Fiber Laser Marking Problems

Two of the most common fiber laser marking problems users often experience are weak laser beams or low-quality code printing, described in more detail below. 

The Beam is Too Weak

Fiber lasers are known for using highly-concentrated beams of light to mark substrates. Compared to other laser marking options, such as CO2 systems, fiber lasers create beams with shorter wavelengths, enabling users to place high-contrast markings on metals and plastics. 

However, there are cases when fiber laser beams are not as strong as they should be. These declines can be sudden, as many users have randomly experienced drops in beam strength after just one day. 

Unfortunately, there is no simple answer as to why a beam would suddenly become weaker. Instead, users must check multiple factors to discover the source of their problem. To begin addressing the issue, we suggest taking the following steps:

1. Confirm the power source is stable: Use a multimeter to measure the laser source power supply. If the meter reveals proper voltage, you can confirm the power source is not the problem. If the meter reveals a lower voltage or voltage instability, it’s time to replace the power supply.
2. Make sure the F-theta lens is clean: Clean lenses are key to producing a strong laser beam. If your F-theta lens is dirty, clean it and see if that resolves your problem
3. Review pulse width and frequency: All fiber laser systems have unique max pulse width ranges in accordance with their power supplies. If your specifications exceed the required range, it will cause problems with your beam strength.
4. Check your signal wire/power supply connection: Power disconnections and signal interferences will naturally disrupt the marking process. Always make sure that your power supplies are well-connected if you’re experiencing marking issues.

If you perform all of these actions and still can’t find the source of your problem, you may have overworked your laser system. Fiber laser sources last up to 100,000 hours; beyond that period, laser sources will continue to become weaker, leading to lower quality beams. Laser sources will also expire more quickly if they are consistently used to complete high-powered marking applications.

Scheduling a professional maintenance appointment will reveal if this is the cause of your problems. 

Low-Quality Coding Results

Although printing low-quality codes onto product packaging can negatively affect product appearance, if you use your system to create traceable codes or place essential variable data onto packaging, unreadable/unscannable markings can also place your products in violation of:

• Federal regulations.
• State-level laws.
• Distribution network policies.

These violations can result in fines, recalls, and other expensive consequences. As such, it’s essential to quickly address marking problems before products are sent into distribution. 

Although a weak beam will naturally lead to lower quality codes, it isn’t the only reason that your markings may look lackluster. Low-quality codes can arise for a variety of reasons, some of which have quick solutions. However, many of these problems do require professional attention. 

Before scheduling a maintenance appointment, see if any of these factors are leading to poor code quality:

• Light path deviations: Faulty elements like broken lenses and damaged coating layers will cause major code quality problems. Inspect the light path to make sure everything is working as intended.
• Loose mirrors: The optical cavity is where your beam will reach optimal wavelength. If the mirrors are loose, wavelength problems will naturally occur.
• Cooling capacity problems: Factors like insufficient water flow, blocked/bending pipes, and pump problems will all prevent proper cooling, leading to code issues.
• Temperature/humidity issues: Your chiller cannot be more than three degrees from room temperature for proper operation. Similarly, excessive humidity will lower code quality. Make sure that your temperatures are set correctly and that the optical cavity is dry before coding. 
• Dust presence: Your field lens needs to be free from dust to facilitate proper marking. Inspect the lens and perform any necessary cleaning before testing code quality.

If none of these issues are the cause of your quality problem, it’s time to seek professional maintenance.

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