Seven Ways to Handle Uneven Color on Metal Stamps

Color inconsistency when marking metals is often caused by improper parameter settings, material characteristics, or environmental factors.The seven practical processing solutions include optimizing laser parameters, pre-processing materials, and operational techniques. They help to solve the problem of color differences in marking, thereby enhancing the aesthetic quality of the marking and the stability of the process.

Why does the color of the metal marking not come out evenly?

Many people who use laser marking machines find that they are constantly adjusting the parameters to get the laser to produce the same depth of marking.In fact, there may be several "troublemakers" behind the scenes, such as the laser power being uneven, or oil residue on the surface of the material not being thoroughly cleaned off. Even changes in the workshop temperature can affect the outcome.Don't be too quick to blame the machines. Let's look at how we can solve the problem!

Adjust laser parameters.

Power and speed must be a good team.

Too high and the metal will burn; too low and the color won't be clear.It is recommended that you first test a small sample, keeping the power within the range the material can withstand, while adjusting the speed appropriately.For example, stainless steel usually comes out with a more even color if the laser is set at 30 % power and 800 mm / s speed.

The frequency is not for show.

High frequencies work best for fine patterns, and low frequencies for large areas.If you see a lot of color noise, try raising the frequency from 20 kHz to 50 kHz. You will see that the edge noise is reduced and the overall color is more uniform.

The material must be prepared properly.

Cleanliness is more important than you think.

Don't think that just because the surface looks clean it's ready for stamping. Even the grease from a fingerprint can leave a spot.After wiping the surface thoroughly with alcohol and a lint-free cloth, use a hot air gun to dry it. Never underestimate the importance of this step.

Special materials require special handling.

For example, with anodized aluminum, it is suggested that the surface be lightly sanded with 2000-grit sandpaper to break up the structure of the anodized layer, and then the marking is done. The color will appear much more even.

Control environmental variables.

Temperature is not a mystery.

If the temperature in the workshop varies by more than 5 ℃, it can lead to the thermal lens effect, in which the focal point of the laser shifts.Installing air conditioning or moving to a shady spot can make a big difference.

Humidity is also important.

In the rainy season, the metal surface can easily condense.If you place a dehumidifier beside your printer and keep humidity between 40 and 60 percent, you'll find that color saturation improves.

Regular equipment maintenance.

Lens cleaning period.

The lens should be cleaned at least once a week with special lens cleaning fluid. Never rub it with a tissue. An old hand has a trick: breathe on it and then gently wipe in a circular motion. This will reduce the chances of scratching the lens.

Don't be lazy about oiling the guide rails.

If the X / Y axis guide rails are short of oil, they may shake when moving, causing the colors to be uneven.It is recommended that you apply a thin layer of lubricant to the instrument every month, being careful not to apply too much.

We are trying to help the handicraft industry.

Coating technology.

For especially difficult alloys, special coatings can be tried.By spraying on a thin layer of paint and then reworking the piece, the artist can achieve a uniform color or a multi-colored effect.

After processing, the jade is polished.

If there are still small imperfections, a polishing wheel with fine fibers is used to give the piece a light buffing.The trick is to follow the grain, and to use just enough force to remove the patina without damaging the base material.

Following these steps will solve 90 % of the problems with uneven color.If you do encounter some difficult problem, remember to keep a small sample of the material to facilitate technical analysis, after all, every machine has its own personality.