White Ceramics: Can't See the Mark?

Are you having trouble with blurry or low-contrast laser marking on white ceramic? We offer three practical solutions to help you quickly solve this problem and improve your product identification quality: optimizing laser parameters, pre-treating the ceramic surface, and using an auxiliary coating.

Why is it that the markings on white porcelain are so easily blurred?

When many people first use a laser engraving machine on white ceramics, they find that the engraved design turns gray, the edges are blurred, and it looks like the object has a foggy coating.This is mainly because ceramics have a smooth surface that reflects light strongly, so the laser energy is easily reflected and scattered.Furthermore, the white background lacks natural contrast, and the patterns are not as vivid.But there's no need to panic. There are three ways to solve this problem.

Adjusting the parameters of the laser marking machine.

Matching power and frequency.

If the power is too high, the surface of the ceramic will be burned; if too low, the engraving will be too shallow.The author recommends starting with a 30-watt unit and setting the frequency to about 20 kHz.If the lines are still fuzzy, the frequency can be raised to 50 kHz to make the laser spots denser.

Optimizing speed and density.

The speed at which the knife is moved is also important. Too fast and the energy may not be sufficient to penetrate the wood. Too slow and the carbonization may be excessive.In practice, controlling the speed at 800-1200mm / s and reducing the spacing to within 0.02mm produces a more continuous line.Remember to use the leftover material for a gradient test.

Surface treatment.

Polishing increases roughness.

Use 2000-grit sandpaper to lightly sand the area to be marked, breaking up the smooth surface.Pay attention to keeping the pressure even, to avoid producing obvious scratches.As a result, the surface of the ceramic is more readily able to absorb the laser energy, and the blackened effect of the engraving is improved by more than 30 %.

Alcohol is used to remove oil stains.

When ceramics are taken out of molds, there may be mold release agents left on the surface.Use a non-woven cloth soaked in medical alcohol to wipe the area where the label will be placed, using a circular motion. Wait until the alcohol has completely dried before proceeding.This small action allows the color to be more evenly distributed.

Use a protective coating.

Special additives for printing.

There are laser marking enhancers on the market. After spraying, the surface is covered with a nanometer-scale layer of light-absorbing material.The measured contrast can be increased by two to three times, and it is particularly well suited to carving fine patterns such as QR codes.When using it, remember to apply it in thin coats, and don't spray it on too thickly.

The temporary marker pen.

In emergencies, the area to be marked is painted with a black marker, and then the design is carved directly into the paint.Although they are not long-lasting, they can produce clear patterns in a short time.These are ideal for samples and temporary signs.

Finally, it is important to remember that different ceramic materials (such as alumina and silicon nitride) react very differently to lasers.If no improvement is found after trying all of these methods, it is recommended that you contact the material supplier to confirm the ceramic components and then adjust the plan as needed.