Environmental control: How does temperature and humidity affect the precision of laser marking?

March 11, 2025

Temperature and humidity are key environmental factors affecting the precision of laser marking.The team analyzed how changes in temperature and humidity cause materials to deform and light paths to shift, and provided practical solutions for controlling the laboratory environment to help improve quality and equipment stability.

Why does humidity affect laser marking?

Many people may think that a high-tech machine like a laser marking machine is not very sensitive to the environment. But in fact the opposite is true, and temperature and humidity fluctuations are often the "silent killers" that cause unstable marking results.

Take for example the time when our lab was having trouble with blurry lines in our markings. After a half-day of trouble shooting, we discovered that the air conditioning had broken down, causing the room temperature to increase by 3 ℃.Later, the team discovered that the high temperature caused the metal material to expand slightly, and the focal point of the laser was shifted, affecting the precision.So, temperature and humidity control is really not a small matter!

A chain reaction caused by temperature change.

Most materials expand when heated and contract when cooled.Materials like metals and plastics, which are often used for labeling, can develop double images if there is even a 0.1-millimeter distortion.Even more problematic is that the optical components in the laser are very sensitive to temperature. The focal length of the lens changes, and the efficiency of the cooling system drops. These factors all directly reduce the precision of the marking.

The high humidity is a hindrance.

The dampness of the environment makes things even more difficult for the residents.When there is too much moisture in the air, the laser beam is scattered and its energy is dissipated.We have tested this: When we laser mark stainless steel in an environment with 70 % humidity, the depth of the marking is 15 % less than in a normal environment.Moisture can also condense on the lenses, requiring frequent cleaning or even damaging the optical components.

Practical techniques for controlling the laboratory environment.

To ensure high quality, it is suggested that attention be paid to the following three points.

Step 1: Monitor yourself in real time.

Don't rely on your body's temperature sensor: Place a humidity and temperature sensor that records data in the equipment area, and it's even better if it can send you a text message when the temperature is out of range.We recommend keeping the temperature between 20 and 24 degrees Celsius, and the humidity between 40 and 60 percent.Some high-end laboratories also install sensors in the area where materials are stored, because the temperature and humidity of the materials themselves is also critical.

Step 2: Layout is important.

Don't ever place the laser marking machine next to an air-conditioning vent or a window.Sudden changes in the temperature and humidity of the air can cause the local temperature and humidity to fluctuate violently.We've learned from mistakes: One machine was located too close to a hallway, and every time someone opened the door, the humidity would change, so we had to add a curtain to solve the problem.

Step 3: Prepare a contingency plan.

No matter how careful you are, accidents can't be avoided.It is suggested that you always have a dehumidifier or desiccants on hand, and have a backup power source for your air conditioning.One summer, there was a power outage. We relied on the ice packs and the airtight seal to keep the temperature in the equipment area stable for two hours, and so saved a batch of orders from being ruined.