Giant polypropylene rollers at the 3M factory generated so much static electricity that it formed a strange "invisible wall" that would alarm and impede employees there. William Beatty, citing David Swenson, described the peculiar phenomenon in 1996—as observed in late summer in South Carolina, August 1980, in high humidity.
The spools ran at 1000ft/min, or about 10MPH. The PP film had been manufactured with dissimilar surface structure on opposing faces. Contact electrification can occur even in similar materials if the surface textures or micro-structures are significantly different. The generation of a large imbalance of electrical surface-charge during unspooling was therefore not unexpected, and is a common problem in this industry. "Static cling" in the megavolt range!
On entering the factory floor and far from the equipment, Mr. Swenson's 200KV/ft handheld electrometer was found to slam to full scale. When he attempted to walk through the corridor formed by the moving film, he was stopped about half way through by an "invisible wall." He could lean all his weight forward but was unable to pass.
Sounds like a SCP! Skepticism abounds about the hardness of the "wall" as remembered, but the phenomenon is for real. Wired's Rhett Alain posted about the weird physics around plastic sheeting a few years ago, with instructions on how to recreate the effect on a smaller and less menacing scale.
It turns out that pulling apart (not just rubbing) two materials can also create a separation of charge. Here is a simple demonstration of this effect that you can do at home. Get some clear sticky tape (really any brand will probably work). Pull off a piece of tape from the roller—make it about 10-20 cm long (a little longer than a pencil). Fold one end of the tape over itself so that you make a little "handle" on the top. Now stick this tape onto some hard surface—like a table. If you want you can write a label on the handle of this tape. Write something like "L" for lower. Next repeat this with another tape about the same size and place it on top of the "L" tape. Write "U" on the upper tape for upper.
I remember when they brought a Van der Graaf generator into school and invited up the guy with longest wispiest hair to touch it.
Previously:
• Static electricity is ruining your morning cup of espresso. Here's how to fix it
• Static electricity: How does that work?
• How dryer sheets work (video)