[tdiaz]

I'm having a heck of a time with certain cuts in coroplast, particularly complex cuts where a lot of work is done in a small area. If I don't have a certain amount of power, I can't cut all the way through unless I go so slow that it heats up and makes a mess anyway, likewise the same with the opposite end of the spectrum. If I turn up the power and cut faster, I still end up with the same thing.

Boosting the air flow from the cut head doesn't make that much of a difference either.

Do I need that much *more* air flow?

It's a 100W laser, and even running as slow as the 50W did, with about as much power it still does that.

[zax15uk]

Standard Coroplast is a polypropylene polymer so melts when cut with a laser, this does make it difficult to do detail.

I would recommend using a smaller spot size to reduce the HAZ (heat affected zone) to a minimum, this should retain more detail. Your 100W laser may need a different lens to accomplish this.

Additional assist gas pressure may help too, but it is likely the edge melting will still be present unlesss you can cut at a much faster rate. Two-pass cutting may be required.

There are also some fluted plastics which look like Coroplast but contain PVC, avoid these - and watch for the yellow/green smoke!

Zax.

[tdiaz]

The smoke is white, and I made sure to buy "Coroplast", not a clone.

The vendor from whom the tube/mirrors came from said it's all good up to 200W, it was a 50W setup before. I think I'm going to just isolate the specific part that has issues and see about doing it separately, rather than doing most of a 24" x 48" in sheet before getting to that spot.

The thing thats getting me is the top of the cut is fine, it's the bottom side that gets all weird. Too much heat in a small area.

http://17500mph.com/DSCN9682.JPG - this is the bottom.