Cutting acrylic

Hi - I found a free source of acrylic sheet at work
Its from discarded TV LCD screens . This is 2mm clear acrylic.
I have found it cuts well but sometimes leaves a sticky residue
that marks the surface of the sheet. Has anybody else noticed this effect.
and can I avoid it ?
I am running a K40 with a strong air assist.
Colin, Bristol UK


I used to get this. I now smear the acrylic with washing up liquid before cutting or engraving. Works a treat.

Do some tests, you do not write anything about your settings but as a rule of thumb - as quickly as possible with the least necessary power and with acrylic with very little air, just enough to keep the lens clean.
I have not found my test disc with 2mm acrylic, but 4mm I cut with 17.5% and 200mm / min, so I think the same energy but with 400mm / min. will be able to give reasonably fine results.

Hi Thanks for the reply - I did some experiments and found that 5mm/sec 25% power worked well.
I suspect that there are different mixes of acrylic. This stuff was used as the light pipe/diffuser in LED
Televisions. I noticed it seems to smell more than my usual acrylic. My k40 has its air out through the window via long flexible pipe with another 4 inch inline fan on the way., but the smell still leaks from the K40 ! I might try a foam seal around the lid.
Thanks - Colin

I think this is not a good idea, in fact I have opened my lid approx. 5mm to get enough air for the fan. I also have it like you, outside. You must always have a slight excess of air in relation to the extraction otherwise “you draw false air”.
Acrylic stinks a lot, I have started building an activated carbon filter but have not finished it yet.