Separating aluminium sheets with magnetic field

Question

all! I would like to know if it would be possible to induce a strong enough magnetic field in sheets of aluminium so they would be separated between each other, like when you use magnets to separate steel sheets between each other like in this example http://www.ibsmagnet.com/products/spreizmagnete/spreizmagnete.php I know aluminium is paramagnetic and that it is possible to induce opposing magnetic field in it like with eddy current, now I was just curious if it would be possible to keep sheets magnetised and thus separated from each other. Thank you for answers!

Answer 1

It may be possible to separate aluminium sheets in a slightly different way:

Moving a permanent magnet along an aluminium sheet shows a kind of friction caused by eddy currrents that are caused by the changing (moving) magnetic field.

Depending on the geometry of your application, the "friction" may be used to move the top sheet of a stack sideways, similar to using a friction wheel, but without applying pressure that also makes the top sheet stick to the second.

This assumes that the eddy currents are much stronger in the top- than in the lower sheets.
It may require electrical isolation between the sheets.

Update: I tried

On revisiting the question, I got curious enough -

I just did a small qualitative-only experiment:

I used

• a stack of four household-grade aluminium foil sheets

  • Size 120 mm * 60 mm * 0.01 mm.

• a strong permanent magnet

  • Material NdFeB, rating N35, cilindrical, diameter 30 mm, total length 45 mm
    (build as a stack of three separate equal cilindrical magnets.)

Manually, I moved the magnet horizontally above the stack with a distance of 5 - 10 mm and the speed like of a quick gesture.

All sheets experienced some drag, but it was significantly stronger for the first layer than the second, with weaker effect further down.

So this effect seems suitable to separate a aluminium sheet from a stack. The shape, strengh, location and movement would need to be choosen according to the local situation.