In 2026, laser marking machines will be one of the core products of the Suzhou OMA Brand. With the increasing sales volume and prolonged usage of a large number of laser marking machines, some customers may encounter the issue of unclear printing from these machines. Today, OMA will discuss the specific causes and solutions to this problem with you.
First, before conducting in-depth troubleshooting, please ensure safe operation: turn off the device power and wait for the laser head to cool down completely before performing inspection and cleaning. This is to avoid accidental laser injury and burns.
The following are the specific causes and troubleshooting steps for unclear printing of laser marking machines:
I. Hardware Issues of Laser Marking Machines
This is the most direct cause, usually related to optical components.
- Focus Lens/Field Lens Contamination: This is the most common cause.During the marking process, lasers generate tiny smoke, dust, and spatter. These contaminants adhere to the protective lens of the focus lens or the focus lens itself. The common symptoms include overall blurry laser marking, stains, and insufficient energy, leading to thickened and fuzzy lines.The solution is to gently wipe the lens with special lens cleaning paper and anhydrous ethanol. Be gentle in your movements to avoid scratching the lens coating.
- Output Optical Path Deviation of the Laser Head:When the laser machine is subjected to vibration or impact, minor deviation may occur in the internal optical path. This causes the laser to not pass through the central optical path completely, resulting in energy loss. A common sign is uneven depth of laser marking, with some areas being unclear.In such cases, professional technicians from Qianli (Note: refers to the designated technical service provider) are usually required for adjustment and calibration. Users must not attempt to operate it themselves.
- Laser Power Attenuation or Aging:As the laser is used over time, its output power will naturally attenuate. A typical symptom is that even when parameters are set to the maximum, the marking remains very faint and blurry, failing to reach the previous depth/contrast.For factory users, it is necessary to contact the manufacturer to test the actual output power of the laser. If necessary, replace the laser.
II. Issues with Marking Materials (Objects to Be Marked)
Laser marking is achieved through physical or chemical reactions between the laser and the material surface, so the material itself is crucial.
- Material Mismatch:Different types of lasers (e.g., fiber, CO2, UV) are suitable for different materials. For example, fiber lasers work well on metals and plastics but poorly on transparent materials and certain polymer materials; CO2 lasers perform well on non-metallic materials (wood, glass, leather).If the laser machine fails to mark at all or only leaves very faint marking traces, it is necessary to confirm whether the laser machine type is suitable for the current marking material. For instance, marking transparent plastics or white plastics may require a UV laser machine.
- Inconsistent Material Surface Treatment:If the material surface has oil stains, water stains, uneven coating, or inconsistent oxide layer thickness, the laser marking may be intermittent, with "blotches" or "water ripples," and some parts may be clear while others are fuzzy.In this case, use cleaning materials to clean the lens surface and ensure the marking area is clean, dry, and uniform. For coated materials, parameters may need to be adjusted to match the coating.
III. Software Parameter Setting Issues of Laser Machines
Marking parameters are key to controlling the interaction between the laser and the material.
- Insufficient Power Setting:If the laser power is set too low, it will be insufficient to cause effective changes on the material surface. The common solution is to gradually increase the laser marking power until the marking becomes clear. Do not increase it too much at once to avoid damaging the material or lens.
- Excessive Marking Speed:If the production line speed is too fast or the laser head moves too quickly, the laser will have too little action time at each point, leading to insufficient energy accumulation and unclear printing. At this time, appropriately reduce the marking speed to allow the laser enough time to interact with the material.
- Inappropriate Frequency Setting:The light source frequency of the laser machine determines the density of laser pulses. Both excessively high and low frequencies may affect the marking effect.Too low a frequency may result in discontinuous dotted marking; too high a frequency may cause excessive energy heating and blurry edges. Adjust the frequency according to the material characteristics: generally, higher frequency is required for metal marking, while lower frequency may be needed for non-metallic materials such as plastics.
Finally, if you encounter difficult-to-judge or unsolvable laser machine problems, remember to contact OMA's technical support immediately. Especially if none of the above steps work, it may indicate a hardware failure (such as a laser or optical path failure), and you should contact the equipment supplier's after-sales service right away.
