Solving the Problem of Gray Laser Engraving

The laser marking color turning gray is a common problem and could be caused by material characteristics, parameter settings or the state of the equipment.With hands-on guidance, you will learn how to optimize the material pre-treatment process by adjusting the parameters of power, speed and frequency. You will also learn how to clean and maintain the equipment, so that the laser marking effect will be restored to its original clarity and brilliance, and the problem of the color turning gray will be resolved.

Why does the color of a laser etching turn gray?

Let's not start adjusting parameters just yet. First we have to figure out where the problem is.There are three main reasons why the color of the laser marking might turn gray: the surface oxidation layer was not completely removed, the laser power and speed were not properly matched, or the lens or galvanometer mirror has accumulated dust.For example, if stainless steel is not cleaned with alcohol beforehand, it can leave a grayish mark.

Three steps to solve the color-fading problem.

Step 1: Inspect materials and pre-processing.

Don't underestimate the importance of cleaning the surface of your materials! Use non-woven cloth and alcohol to clean the material twice, especially metal. Remember to air-dry before putting it in the machine.For plastic, you can try using a flame gun to quickly pass over the surface (be careful!).

Step 2: Adjust the laser parameters.

Setting the parameters is like cooking a dish: you have to get the right mix.Too low a wattage results in a pale color, and too high a wattage burns the filament.I suggest starting with the basics:

- Metal materials: power adjusted to 60 to 70 percent; speed reduced to below 800 mm / s.

- Plastic: 40-50 % power, 1000mm / s speed.

During the engraving process, the operator can adjust the frequency to produce a finer line (for example, from 20 kHz to 50 kHz).

Step 3: Deep maintenance.

The longer a machine is used, the more it is like looking at things through dark sunglasses--the effect is certainly reduced.Do these three things every month: 1.

1. Use only special lens paper to clean the focusing lens. Never use a tissue to scrub it.

2. Check the cooling water pipe for bubbles. If the water temperature exceeds 25 degrees, change the coolant.

3. Apply a special lubricant to the rails to ensure smooth movement of the laser head.

Special techniques for special situations.

If these steps don't work, try this:

Black anodized aluminum: In the software, change the engraving mode to "deep carving.

Glass: Spray a thin layer of water on the glass before marking (be careful not to create standing water).

During mass production: Blow the workbench with an air gun every two hours to prevent dust from accumulating.

By following these methods step by step, you can basically solve more than 90 % of the problems with grayish color.If it still doesn't work, perhaps the laser tube is old and it's time to contact the manufacturer to replace the part.