Cutting with air : abrasive jet without the abrasive, or the water 1

[walterf]

I'm trying to do some research into using high pressure air as a cutting method for thin tissue (medical) as opposed to using water from a water jet. Does anyone know if this is potentially possible (or completely ludicrous), and where I could potentially find some more information on the subject? I seem to be only sucessful in tracking down an abundance of info on "air cutters" and not cutting, using air.

Thanks in advance,

~Walter

 

[Cockroach]

I don't know if this is functional.

In jet cutting, using fluid with industrial diamond particulates equivalent to Grade 60 sandpaper, the sonic velocity is typically 2.5 Ma, maximum. This leaves a super clean cut, no rag edges on steel thicknesses up to two (2) inches. Hydro jetting is essentially an noncompressible fluid application, using gas (i.e. air or nitrogen) I can see a miriad of technical issues.

For medical applications, of course the membrane is much thinner and mechanically weaker than steel. This may proove helpful in reducing your sonic velocity, but I still think you may need some sort of particulate additive to get the job done. For medical, I would have absolutely no idea what that additive would be!

Good luck with it, I think you're better off with laser.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[walterf]

Lasers cause undesirable byproducts due to the heat. (burned / heat effected tissues). This is cutting a tissue that is to be implanted. Cutting of the tissue occurs during the manufacturing process.

 

[unclesyd]

You might try this website. We used quite a lot of their equipment. I would give them a call.

http://www.airbrasive.net/

 

[MikeHalloran]

Providing a supply of air that doesn't have water, rust, and assorted crud in it is expensive at any pressure, but I can understand your incentive.

It might work. It might work better with an abrasive, like salt, or sodium bicarbonate. Understand that the entire abrasive supply and entrainment circuit will be a consumable.

You also need a backstop, to dissipate the jet after it's cut the workpiece. In plasma cutting metal, we use a pan of water, with a semisubmerged array of consumable metal bars to support the workpiece.

In our case, the workpieces are sheets of metal. They are heavy enough to not require clamping to prevent the reaction forces from moving them; the reaction forces are not very large relative to the weight of the workpiece.

In the case of cutting tissue, you will need to clamp the workpiece in place to prevent the jet from relocating it across the room. You will also need to capture the ejecta and clean the machine regularly; yecch.

Sounds like fun.

Oh, yeah, speaking of sound, you will need to enclose and guard the machine to prevent operator hearing damage, also a problem with waterjets.






Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[GregLocock]

As a sideways step, how about using ground ice as the abrasive in an airblast?



Cheers

Greg Locock

 

[dkelly]

Greg

You might have been joking but check this out link

http://www1.boc.com/eco-snow//

this company uses compressed CO2 as a high pressure "sandblast" media with the resulting media vaporizing when done. Pretty cool!

danno