[greif]

I am looking at small laser engravers (30-40W) to mark glass (sodalime, fused silica, bk7, typical) with serial numbers and occasional use as cutting tape or Mylar.
Will air assist help produce better results for this application?
Is air assist different than just shooting an air jet at the burn area? (which could then be added to machines which do not have it)
Thanks,
gr

[zax15uk]

You would not normally require air assist for those applications.

It is as you state just a matter of blowing a gas (often air, N2, He or Ar) at the laser spot location. Yes you can easily retrofit air assist, although you may need to make or purchase a nozzle/tip.

There are several benefits (these are the main ones):

1. It keeps the optics clean, particularly useful when cutting materials that generate fumes (particles on the lens/mirrors absorb energy, generate heat and can be damaged).

2. The gas keeps the laser spot location clear of debris and smoke which results in a more consistent and clean cut/engraving.

3. Using an inert gas (even air helps) prevents 'flame up' or burning on wood and plastics.

Depending on your marking requirements it will likely require low power. The energy generates a micro fracture at the glass surface which is what appears opaque.

Zax.

[LaserImage]

Air assist will do nothing to make the mark any better on glass. It is invaluable when vector cutting and helpful when rastering, but not with glass. Glass doesn't ablate like acrylic, wood, etc., it microfractures. This gives a suedo-etched look, but nothing like other marking methods. If you want a frosted look, or any depth at all, you really need to consider sandcarving. You can use photo-resist and get some amazing detail and the mark is far superior to anything you can do with a laser. I have both technologies and will use the laser to mark glass occasionally, but if I want a frosted look I will always use sandcarving instead.

Gary

[Litografa]

I suggest use of air assist when engrave on glass very often.
Reason is what "zax15uk" described in 1). If you will engrave a lot of glass, especially big areas, you will have a lot of glass dust inside laser. It could be harmful for your mechanical moving parts. Air assist now cost nothing and laser still cost over 4000 USD. So better have more caution, than less

[zax15uk]

I suggest use of air assist when engrave on glass very often.

I have found air assist causes the opposite when engraving glass. The particles/dust are spread around more inside the machine. I also disable the exhaust and use a solution of water and liquid soap on the surface. This helps improve the marking quality making it crisp (smaller fracture) and prevents the particles from spreading. A damp paper towel does the same but can dry out.

Zax.

[Litografa]

We also reccomend to customers use of solution of water and liquid soap for glass engraving. We just put old newspaper on glass and add water/soap on it and engrave thru wet paper.
But about air assist will try make better explanation. We are selling GCC lasers and their construction looks like table is in air. There is space between table and laser walls. Air exaust is mounted UNDER the table. So air assist throw all dust/debries under the table and after exaust easily remove thaem from laser. The construction of some other lasers I see is different and in this case air assist can do negative work