Thin non-magnetic sheet seperation.

[lwLaser]

Anyone know of a sure way or separating sheets of thin non-magnetic material consistently? Or a machine that can do that. We run through our laser 5 to 6 pallets a day of 20, 18 or 16ga SS. The sheet separator on the loading machine has the conventional pumping actin of the a vacuum cup and air blowing. This is a very poor way of sheet separation and doesn't work reliably enough. What we do now is put in thin sheets separators between every sheet before we load it unto the machine. Any tips or ideas would be helpful. Thanks.

 

[JayMaechtlen]

It may be poor but it's about the only way we have.
Look at how the air jet is aimed - maybe you can adjust its position and/or flow rate to improve performance.

so, how do your people get the sheets apart to put in separators?


Jay Maechtlen

http://www.laserpubs.com/techcomm

 

[lwLaser]

We use steel straps that have been chopped into 2" pieces. They get hammered in between every sheet.
This is a fool proof way of getting it to work, but it takes time and I would imagine there should be a machine out there that can separate this kind of material already. Let me know what you think.

 

[IRstuff]

"This is a fool proof way of getting it to work, but it takes time and I would imagine there should be a machine out there that can separate this kind of material already. Let me know what you think. "

But there isn't a way, otherwise, someone would have built one The bottom line is that your individual sheets weigh too much for vacuum to work, but there is no other option.

TTFN
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[Foostrap]

Best is to have a strong peeling unit, and blow air underneath the plate while peeling. The sheet should also be lifted while peeling.

 

[lwLaser]

The peeler can lift the sheets no problem, as a matter of fact the peeler will lift all of the sheets of the pallets in the corner if they are stuck together. So it's plenty strong, it's just not a good way of separating sheets reliably. Like I said a peeler and air blowing is not reliably enough for most of the pallets we put through, it's good "enough" 90% of the time, but we need something that works closer to 100% all night long, otherwise there is nothing getting done during a night run.

 

[Foostrap]

Adding a steel brush by the peeling unit should also help. When peeling, the edge of the sheet should touch the brush and separate.

 

[lwLaser]

A steel brush only helps if sheets are precisely stacked one on top of the other. We did have a steel brush on one of our machines, it made so little difference that we didn't see much of an advantage over not have one at all.

 

[Foostrap]

On the picture you posted, the stack looks good, and brush should help for those. Less than 1/4" deviation in stacking of the sheets should be OK with a 1/2" brush. Strenght and length of the brush is critical. Of course, the brush will have to be replaced often as it will wear off quickly if sheets are not stacked very well.

 

[lwLaser]

Sometimes the mills cutting the steel have dull cutting tools. What happens then is the sheet on top has a slight burr along the cutting edge that curls down and hooks unto the sheet on the bottom. This is a very small burr, but you can feel it with your hand and see it if you look reeeeeally carefully. This type of stack will NOT separate period, it needs separators. That's why I'm looking for something different that will work in all of these different scenarios.

 

[IRstuff]

Presumably, your sheet lifter can tell how much weight it lifted, and perhaps banging on or shaking the sheets might separate them.

TTFN
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[krugtech]

Have you talked to your steel supplier about this? I've been through this and there's just some steel suppliers who like to unintentionally glue their sheets together pretty solidly w whatever process fluids they use to make them.

Chris Krug

http://krugtech.com/

Maximum Up-time, Minimum BS

 

[IRstuff]

Just about anything vaguely fluid will stick two sheets together. Perhaps you can get your supplier to talc the sheets ;-)

TTFN
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[JayMaechtlen]

here's a nice, Rube Goldberg idea:

A rotary wire brush on a track - prior to lift, the brush spins up (rotation to lift the top sheet?)
traverses the sheet, with air blowing into the edge behind it
While the lifter is operating only on that edge of the pallet.
Then engage the rest of the lifter.




Jay Maechtlen

http://www.laserpubs.com/techcomm