Newbie- Heating Through Glass...

[ZOMGVTEK]

Say I have a thin substrate sitting on a perfectly flat surface, such as glass. On top of this substrate, is a foil designed to bond under heat and pressure. If I were to apply another sheet of glass on top of the two, to hold them in place and provide the marginal pressure required for adhesion, would a 40W CO2 laser be capable of heating the foil under the glass? The glass could not be one time use, but 10+ uses would be fine. The design would need to be heated continuously from start to finish, and no other methods do this properly. Obviously the laser could not cut the foil or substrate, but simply heat it. I would imagine with acceptable control over power and speed, this could be done reasonably effectively and repeatably? The normal method for this is a thermal printer, so thats the kind of heat and pressure we are talking about. The only problem with the thermal printer, is it would not be possible to heat the design continuously and there would be breaks.

Is the glass going to be a major issue? Would there be a better way to provide pressure and hold the extremely thin substrate in place that the laser wouldn't mind? Were talking low power levels here, so I would imagine the glass should transmit enough power and a tight enough beam to work fine, but I have no experience with a laser engraver.

[Geof]

What is the wavelength of the laser? Ordinary glass absorbs infra-red radiation so you are likely to heat the top surface of the glass overlay not the foil. Also if the foil shiny it will not heat efficiently due to reflection.

[ZOMGVTEK]

Originally Posted by Geof What is the wavelength of the laser? Ordinary glass absorbs infra-red radiation so you are likely to heat the top surface of the glass overlay not the foil. Also if the foil shiny it will not heat efficiently due to reflection.

I'm not entirely sure. This would mostly be used for prototyping, so it does not need to be a perfect process, just produce a useable result. I was looking into the cheapest Chinese laser available, it looks like something like this is what I would be looking at....

Wholesale - mini laser cutter small laser cutting machine | DHgate.com

Would some sort of cheap generic garbage like this be capable of what I want to do? I feel reasonably comfortable getting the unit up and running, the question is if these low end units can do what I want. I would like this to be <$2K. It does not need to last terribly long, or be that powerful or amazing. It simply needs to provide a point source of controllable heat, and probably wont have more than 50-100 hours on it.

It looks like the 40W Chinese lasers tend to be about 10.6um, which would be IR. This might be a problem. Is there something fairly heavy, flat, and cheap thats invisible to high power IR?

[Tweakie]

I think there are much more efficient ways to heat the glass than to use a laser. The problem is that the laser would generate a single point heat source within the glass and unless it was continuously scanned to distribute the generated heat the glass would crack / shatter.

Tweakie.