Water jet cutting prefinished material with UHB pre applied

Hello All,

I am a new waterjet operator at a sign company in CA. I am only experienced with cutting big parts that were never seen out of steel or aluminum. I was wondering if others have had success cutting pre-finished material (brushed brass, stainless steel, etc.) with good face quality (no haze around edges caused by aggregate)? I have tried cutting through a thin piece of sintra or styrene on top of the material and it helps some but I can still see damage. Maybe something thicker and on both the back and face of the pre-finished material like a sandwich? Has anyone done this? The material that the parts are being made out of are usually very thin (>.090) to only about 3/8" or 1/2" (.375-.5) Also the fabricators in the shop have to spend a lot of time applying VHB (Very High Bond) tape to small letters and intricate parts. Is there a technique used to cut parts with this tape applied before waterjet cutting? I didn't think it would be much of an issue of the tape peeling off from the jet but I haven'y tried it yet. Anyway I know that's a lot of questions in one post of if anybody has info about anything I asked please feel free to let me know.

Thanks,
Jimmy Mc

Cutting VHB tape with anything ends up in a big mess for me, can't see it going well with a water jet either. VHB is not spouse to get wet either i believe prior to use. It uses a acrylic adhesive. hence why it has a plastic not paper release film.

Jimmy:

We've had good results cutting 16oz copper (0.022") on the waterjet. We did not use any aggregate - only water. Second, the work piece was held above the water level - not submerged. Finally we would sandwich the copper between two sheets of cheap 1/4" paneling. Haven't tried cutting VHB but it might work. Give it a shot and let us know how it works out.

Regards,

DB

adama said:

hence why it has a plastic not paper release film.

Click to expand...

That's why it has a plastic backing! The More You Know!

Thank you so much for the insight. I am going to do some test cuts next time I have some down time. I know we only have a 60,000psi water jet (it's a multicam/KMT) and the other operator said he doesn't think it will cut through with water only, so I was wondering is your water jet more powerful?

i have used a KMT powered water jet , techni here Water Jet Machine | Waterjet Machine | Waterjet Cutting Machine .

for general cutting with garnet the hazing you speak of is not too bad on brushed brass or plated copper products, having the nozzle too high you will get hazing other wise its ok, a good nozzle not too old helps as well.

For very thin rubber gaskets that tend to move i sandwich them between 6mm ply and bolt it together it keeps it in one place of course your ply is expendable as it gets cut as well, but is a fix for difficult to cut items.
You can stack a few high between the ply so you cut many in one go.
just squares of ply about 7 inches square bolts in the corners, i fix the ply so it doesn't move.

General thick rubber above 4mm in big sheets tends to stay put usually, thats if you put weights spread around the job, you have to be careful it doesn't get hit by the head or the head pops off and mucks up the zero setting and you junk a part.
I lay out opened up wax cardboard lettuce boxes on the table under the part as it stops the rubber saging in the middle of the slats i replace the wax cardboard for a new cut on the full table its expendable item usually picked up free from a grocer.
I have cut tool steels to stone to non metallic parts and even wood in it.


for getting garnet out of the tank we had a submersible pump in the end corner pumping to a external tank, the agitating of the water jet moves the garnet to the pickup it runs all the time the water jet runs.
The external tank has a bag the one the garnet comes in placed inside there is a overflow that feeds back to the waterjet, the garnet comes out of suspension in the external tank and drops into the bag.
The bag is removed from the external tank with a forklift when it gets full and carted away as waste a new bag is fitted.
The pump lasts about a year due to the grit going through it and then needs a new one.
The waterjet tank only gets cleaned out when needed this system lasts years before it is needed to do so.

you have to be careful not to cut the pump when cutting full table width so you take the submersible pump out when you do those jobs.

it will cut with water only on rubber but the cut quality is no good so don't even bother, you see this when the garnet supply gets blocked.

i should add when we run out of wax cardboard we use whatever is on hand be it old ply from crates to plastic coreflute both work as well as the wax cardboard.