What Are the Reasons for Uneven Effect of Laser Marking Machine?

in FAQs about Laser Marking, , , ,

1. The quality of the laser beam becomes poor.

The quality of the laser directly determines the quality of the laser beam. If the laser beam is not good, the marking effect will be affected.

2. The machine level is not adjusted properly. That is, the galvanometer lens or field lens is not parallel to the processing table surface.

Since the galvanometer or field lens is not parallel to the processing table, the distance between the laser beam passing through the field lens and reaching the processing object will be inconsistent, and the final energy of the laser falling on the processing object will have inconsistent energy density. So Marking inhomogeneity is exhibited on the material. Before using the laser marking equipment, adjust the level of the machine and make the laser galvanometer lens or field lens parallel to the processing table.

3. The laser output spot is blocked. That is, after the laser beam passes through the galvanometer and the field lens, the spot is missing and not round enough.

The laser output head, fixing fixture and galvanometer are not properly adjusted, which causes part of the light spot to be blocked when the laser passes through the galvanometer. The spot presented by the field mirror after focusing on the frequency multiplier is non-circular, which may also lead to uneven marking effect phenomenon.

4. There is a problem with the galvanometer signal, or the galvanometer is external interfered, or the galvanometer deflection lens is damaged.

The galvanometer vibrates slightly during the marking process, so the marked characters or patterns are not clear. When the laser beam passes through the damaged area of the lens, it cannot be reflected well, resulting in inconsistent laser energy.

5. The reason for the material itself.

The uniformity of the material, the uniformity of the texture, the uniformity of the coating thickness, etc. will affect the absorption of the laser energy by the material. When the material is not uniform enough, the effect of laser marking may appear uneven. The material should be carefully selected, the surface coating thickness is the same, and the surface physical and chemical treatment is uniform.

6. Thermal lens phenomenon.

When the laser passes through the optical lens (refraction, reflection), the lens will heat up and cause slight deformation. This deformation will raise the focus of the laser and shorten the focal length. If the machine is fixed and the distance is adjusted to the focal point, after the laser is turned on for a period of time, the laser energy density acting on the material will change due to the thermal lens phenomenon, resulting in uneven marking effect.

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