It’s the air and moisture that’s trapped within the glass that makes laser marking possible with a CO 2 laser.Īs a laser beam strikes the glass, it heats up the glass elements including the silicon and any metal content but neither of these elements will react to the relatively low heat and frequency of a CO 2 laser. This introduces two things into the glass beyond its basic elements: air and moisture. It is then removed from its oven and manipulated in some way. Remember how glass is made? Silicon is heated to 2000‹ or more until it becomes molten. This is really not as much a paradox as it might appear. So, thus far, we have learned that CO 2 lasers can’t engrave glass, nor can they deal with the metal content of glass, yet we have all seen glass items marked by lasers.
Understanding this part of the process is important to laser users because, as all experienced laser users know, you cannot mark metal with a CO 2 laser and that is just as true when the metal is molten (in glass) as it is when metal is in a sheet form. 24 Karat gold on the other hand, produces a unique colored glass called cranberry.
In the case of lead, a considerable amount can be added to glass without affecting the transparency of the glass as you can see in 24% leaded crystal. These are often metals such as lead, zinc, cobalt or even pure gold. To add strength or color to the glass, other elements are added. As the molten glass cools, it remains transparent. This can then be poured into molds or blown by hand. When heated hot enough, the silicon melts and becomes a thick, gooey fluid. In the most basic of terms, glass is made by heating silicon (sand). Ironically, it really does not engrave glass at all but it will mark it and with that contradiction, we will begin to understand how a CO 2 laser beam interacts with glass. the ragged edge of lasered glass.įigure 3: When engraving on glass you may get an inconsistent color if the lens isn’t correctly focused as seen here in the Christmas tree.īecause glass is a “natural” material (that is, its primary elements come from nature), one would think a CO 2 laser would engrave glass pretty well. Others lasers, such as a YAG or Vanadate perform poorly with these materials but have no problem marking many metals.įigure 2: In this exaggerated illustration you can see the difference between the smooth edge of sandblasted vs. It does very well with most “natural” materials such as cork and wood and it does well with acrylic and some plastics. There are any number of different frequencies used by lasers and each determines what it does best.įor instance, the frequency of a low power CO 2 laser like that used in the engraving industry prevents it from marking metal at least in most cases. A YAG laser may operate identically to a CO 2 but because the frequency is different, it will affect materials in a completely different way. That frequency range (wavelengths of the light produced by the laser) determines what the laser will and will not cut.
Glass engraving machine how to#
For those new to lasers, I’ll also throw in some tips about how to get the best results.Įach type of laser works at a specific frequency. This article is intended to share my nearly 15 years of experience as to what lasers will and will not do when working with glass.
Sometimes the information is accurate and sometimes salespeople get a little carried away with their claims. There is always lots of talk at tradeshows and workshops about using a CO 2 laser to mark glass. Figure 1: Cranberry glass known for its distinct coloration lasers well.