First, use defocus to mark a certain range of content. Because each focusing lens has a corresponding depth of focus range, and the defocus marking method will easily cause the edge to be at the critical point of the depth of focus or exceed the depth of focus range, which is easy to cause uneven effects. Therefore, the defocus marking method should consider the problem of laser energy.
The second is that 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. Improper adjustment of the laser output head, fixing fixture, and galvanometer causes part of the spot to be blocked when the laser passes through the galvanometer. The spot of the laser marking machine on the frequency multiplier after focusing through the field lens is non-circular, which may also cause uneven effects.
There is another situation, that is, the galvanometer deflection lens is damaged, and the laser beam cannot be reflected well when passing through the damaged area of the lens. Therefore, the laser energy of the laser beam passing through the damaged area of the lens is inconsistent with the laser energy of the undamaged area of the lens, and the laser energy acting on the material is also different, which makes the marking effect uneven.
Third, the thermal lens phenomenon.
When the laser passes through the optical lens (refraction and reflection), the lens will heat up and produce slight deformation. This deformation will raise and shorten the laser focus. If the machine is fixed and the distance of the fiber laser marking machine to the focus is adjusted, after turning on the laser for a period of time, due to the thermal lens phenomenon, the laser energy density acting on the material will change, resulting in uneven marking effect.
When purchasing a fiber laser marking machine, companies attach great importance to the marking speed of the equipment, because it is directly related to the processing efficiency of the order. So, what factors will affect the marking speed of the fiber laser marking machine?
1. Internal factors refer to the setting of the machine’s own parameters when we mark the product, some of which are the laser frequency, laser, laser power and reasonable auxiliary gas in the laser marking machine. Therefore, when purchasing a laser marking machine in the early stage, you should consider the characteristics of the marking product and your own requirements for the marking effect when choosing the model. When purchasing a product, it is best to choose according to the engineer’s advice.
2. External factors mainly include marking density, marking width, marking depth and spot size. These factors may affect the marking speed of the fiber laser marking machine in actual processing. The higher the marking density, the slower the marking speed, and the larger the deflection area of the large-format marking galvanometer, so the large-format marking speed is slower than the small-format marking speed. Different marking depths require different parameters to be set, which affects the speed of the fiber laser marking machine.