Research on UV Laser  Engraving Machine on Glass Product Process

ABSTRACT: When a beam of light enters the glass, it reflects part of the light on the surface, and the rest goes directly through. This article will guide you to understand and master the processing technology of  UV laser marking Machine on glass surface.

1. Difficulty in glass marking & engraving

When a beam of light enters the glass, it reflects part of the light on the surface, and most of the rest goes straight through. Ultraviolet laser is the same, when ultraviolet laser etching on the glass surface, the need for very high energy density, but too high energy density will lead to cracks or even edge collapse phenomenon, too low energy density will lead to hit the point sink or cannot be directly etched on the surface, so the processing is more difficult.

2. Influencing factors

A． Flat glass

UV laser engraving machine on flat glass is directly related to the peak power of the laser, the final focus spot size, and the galvanometer speed.

We have found that sometimes the light of a high-power laser is not etched on the surface of the glass and will pass directly through it. This is because the peak power of the laser is not enough, or the energy density is not concentrated enough. The peak power is affected by the laser crystal, pulse width and frequency. The narrower the pulse width, the lower the frequency, and the higher the peak power of the laser. The energy density is affected by the spot size, the beam quality M2 of the laser beam (a measure of the laser beam, the value of the laser beam approaching the Gaussian beam, and the Gaussian beam M2 = 1). The spot size can be changed by using a high-magnification beam expander. M2 can only be determined by the beam quality of the laser itself. The smaller the M2 is, the larger the beam expander magnification is, the more concentrated the energy density is.

Some can be etched on the glass surface, but there is still a leak point phenomenon, and some pulse forming point will sink into the glass to form an internal carving, which can be improved by high peak power laser and high power beam expanding.

B. Curved glass with UV laser  machine

In addition, the laser beam contact time on the glass surface also affects the etching effect of the glass surface. Too long contact time may cause the glass surface to be too deep, and too short may cause a leak. We only need to change the scanning speed of the galvanometer to a suitable value to get better processing results. However, it should be noted that the scanning speed is also affected by the frequency of the laser itself. If the frequency is too low, it will also cause leakage.

Because of the influence of the curvature, the focal depth of the final focused spot and the scanning mode of the galvanometer are particularly important for the machining effect, ie, the peak power of the laser coding machine, the final focused spot, the galvanometer scanning speed, the galvanometer scanning mode, the spot depth and the field. Mirror range and so on. When the energy density is up to standard, we will find that the worse the effect on the edge of the glass surface, or even the processing effect on the surface, because the depth of focus is too shallow. The depth of focus is affected by the laser beam M2 factor, the beam spot size of the beam expander, and the field mirror range. The multiple of the beam expander and the range of the field lens affect the focal length. The shorter the focal length, the more concentrated the energy density and the shallower the depth of focus.

For a glass material with a large curved surface and a high hardness, a laser jet printer with a good beam quality and a narrow pulse width should be selected. It is suitable to use a suitable beam expander or a 3D zoom galvanometer to process such a product.

The CYCJET laser has introduced a new 5w~7w (LP106, SP355) water-cooled UV laser for this type of glass marking. This laser has a M2 factor of<1.3, which is close to the value of the Gaussian beam (M2=1), ensuring the beam quality; At 30KHZ, the pulse width can reach 10ns, which ensures the peak power; the water-cooled cooling method ensures the stability of the laser continuous operation. This shows that the laser provides a stable UV source for glass processing marking.

CYCJET is the a brand name of  Yuchang Industrial Company Limited. As a manufacturer, CYCJET have more than ten years experience for wholesaler and retailer of different types of handheld inkjet printing solution, Laser printing solution, portable marking solution in Shanghai China.