# How do I electrically charge a sheet of plastic strongly enough that it firmly sticks to the wall?

## electrostatic whiteboards

I have a bunch of these special dry erase sheets. Someone gave them to me as a gift about a year ago; I see they are still available for purchase on the Internet — you can find them if you look for something like «static cling dry erase sheet» or «electrostatic whiteboard»; they are available from different companies and, as far as I can tell, there is no single standard name for them. I am going to call one such an «electrostatic whiteboard» further in this question.

So, an electrostatic whiteboard is a flexible rectangular sheet, about 0.5 mm thick and about 1 m² in surface. Since it is light, transparent and warm to the touch, I assume it is made out of some kind of a plastic. The magic of it is that, put against a wall, it sticks with enough strength to hold its own weight and then some, but remains easy to peel off, stick again and so on, without any visible changes to either the wall or the electrostatic whiteboard.

Sadly, after about a year of being stuck to a wall and serving me faithfully, my electrostatic whiteboards slid down one after another and lost their stickiness. Even though they are not that expensive, I loathe to buy new ones since it is not environmentally conscious. Rather, I should like to restore the electrostatic whiteboards I already have to their former glory.

## my theory

My understanding is that electrostatic whiteboards come strongly charged with static electricity. They are made of a strong electrical insulator, so it takes a long time for local surplus or deficit of electrons to «escape» to the surface and dissipate. The wall, meanwhile, is covered with paint that is, I guess, dielectric — so, upon coming near it, the electrically charged electrostatic whiteboard polarizes the surface of the wall into carrying the opposite charge and sticks to it thanks to the electrostatic force. However, over time electrons move through the material of the electrostatic whiteboard and it loses its charge. No charge — no stickiness.

## my question

So, how do they charge electrostatic whiteboards at the factory?

I tried rubbing mine against the carpet but it does not help. I tried rubbing a thin polyethylene bag against the carpet and it does stick to the wall, but only weakly — it falls down under its own tiny weight within a minute. So, rubbing sheets of plastic against the carpet does not seem to be an efficient way to electrically charge them.

Should I take a more fluffy carpet? Should I rub more intensely, or for longer? Do I need to charge both sides of a sheet? Should I apply strong enough electricity that the electric charge soaks through the whole depth of the sheet despite its very low electron mobility?

Is my theory overall right or wrong?

• rub it on a cat Commented Dec 16, 2023 at 20:33
• @jsotola   Tried that; only moderate effect. Commented Dec 16, 2023 at 22:12
• Is it the right type of carpet? Commented Dec 16, 2023 at 22:30