Why does plastic wrap stick to surfaces?

Question

Just curious.

Answer 1

Static electricity.

The plastic is a very good insulator and it forms a charge on the film and an opposing charge on the opposite surface, which attract each other.

The film is very light and flexible so the attractive electronic forces easily pull the surfaces towards each other.  The closer they are, the greater the force and so the stickiness is even greater.

Answer 2

I always thought that it was because of humidity. When you put it in the fridge, it doesn't stick to itself, or many other things.....

But the above ^^ answer begs to differ.......

Answer 3

Plastic wraps are generally made from a vinyl or polyvinylchloride molecular configuration, which gives the material its “clingy” characteristic. Plasticizers add stretchiness. The level of clinginess depends on a mix of factors, for example the electrical charge the wrap carries, plus the charge the container carries.

“Glass, as well as some plastics, has a net negative charge on its surface, so a wrap that has an opposite charge is going to cling quite well to these surfaces,” says Hicks, though of course it’s unlikely that you would know what charge your container carries. A plastic wrap that carries the same charge as the container will not adhere as well.

Plastic films can also be hydrophobic (meaning they repel water) or hydrophilic (they attract water). Hydrophobic wrap is better at stretching across the tops of bowls and wrapping deli meats.