I have no idea what the pressure is , we have centralised air thats distributed all over my factory/workshop using a massive 15hp 3 phase compressor. I NEVER use coaxial (air thu lens nozzle coaxial with beam) air assist , I have had poor results with it , I use a small directed tube of the side of the head.
For thinner acrylic stuff we balance air pressure with overcooling , ie we reduce air pressure till edges come out polished rather than "frosted" , for thick stuff we increase pressure cos we want ALL the melt expelled as melt thru the bottom of the kerf , the slow cuts and high powers involved still guarantee enough heat in the cut to polish the edges so the increased air pressure doesn't lead to overcooled and thus frosty edges.
Rodney Gold, Toker Bros trophies, Cape Town , South Africa :
Roland 2300 rotary . 3 x ISEL's ..1m x 500mm CnC .
Tekcel 1200x2400 router , 900 x 600 60w Shenui laser , 1200 x 800 80w Reci tube Shenhui Laser
6 x longtai lasers 400x600 60w , 1 x longtai 20w fiber
2x Gravo manual engravers , Roland 540 large format printer/cutter. CLTT setup
1600mm hot and cold laminator , 3x Dopag resin dispensers , sandblasting setup, acid etcher