Ouch! Electric Shock From Plastic

Static electricity....

Try wearing plastic soled shoes and shuffling around on a nylon carpet in a dry office for a few minutes... then reach for a door handle... Now that is OUCH!!!

John.

Try sliding a 2500mm x 1250mm sheet of plastic coated stainless steel of a shelf! I got knocked of my feet once by the static discharge from this stuff. Of course, no decent person would stand around and watch someone else do the same. He he he.

Re decent person:

Having shocked myself with a capacitor hot off a capacitor tester... you can be darn sure I never even thought of doing any thing like tossing such a capacitor to someone else, just to watch their reaction at the catch.

Ooowwww Ken, we did bacxk in the early 70's in the design labs at Marconi's...

We put a 2u2 capacitor inside a tobacco tin that had insulated lid and container... Then we charged the capacitor up from a handy source 180Volts and left it on the victims bench...

hehehehehehehehehehe we did lots of other things but I must get something to eat...

John.

I would never consider taking one of those condensors (capacitor) while working on points & condensor ignition system and charging it off the spark wire just so I could toss it to someone.

When I worked in a TV repair shop in high school we hooked the output from a black & white flyback transformer to the door knob of the restroom and kept another tech trapped in there for a while. We used to also take the "door-knob" 20KV ceramic capacitors and charge them up to 12kv and toss them around. It is a wonder we didn't kill anyone but it was a rough area and we were bad.

I'd entirely forgotten this until right now. As a very young kid, I ran a line from a running lawnmower spark plug terminal to a door knob. At the time, I don't think I necessarily appreciated that there really should be a "circuit." Without the "circuit" it worked just fine, however, even if the victim (my brother usually) was wearing rubber soles. I guess the effect relies on human capacitance. As I remember, you didn't simply "charge up" and then no longer feel the shocks. I suppose you dissipated a large part of your charge back to the lawnmower between spark pulses, making you ready to feel the next pulse. Fun. Nobody died.

Ahh, I'm so glad that this forum is full of like minded, professional, serious individuals who wouldn't for a moment consider using today's wondrous technological advances for a petty, small minded practical joke. Like, for instance painting your high school teachers door jamb with dry nitrogen iodide. Ooops. Heheheheh.

The dry non-conductive plastic does not contain the moisture needed to ground it out. The static charge accumulates in the item until it is grounded, by you. (or other means)

Carry a -cat. They get a charge in cold weather and the - charge on the -cat will cancel the +charge on the plastic.

Hey Buddy... will the Cat's hair and tail STAND STRAIGHT UP??? like a Halloween Cat..

Don

A Dr. Evil cat will not do. Needs to have fur.

A demonstration of the non-conductive properties of certain plastics, such as nylon, and their propensity to generate static electricity when rubbed with certain materials forms an iinteresting presentation to first-year Physics pupils.

I have witnessed the effects of static electricity generated by rolled-up, untreated, photographic film base. The roll was 1.5m wide, 0.8m in diameter and contained something in the order of 2000m2 of material. A spark (being the discharge from the roll that was behaving like a huge capacitor) 0.5m long jumped across the gap between the roll and a person's knee. Both the roll and the person survived the experience - just!

http://en.wikipedia.org/wiki/Triboelectric_effect

Don't do that!

Actually getting shocked can be fun, if you do it right. If I could choose how to die I would like to be hit by a very large bolt of lightening so that my energy could co-mingal with the electromagnetic pulse and I could be propagated into space at the speed of light. Needless to say, don't try this at home kids.

What happens is that the plastic has been charged with static electricity. There are a number of ways this can happen but in one way or another, the electrons have been stripped from the outside of the plastic (usually by friction - sometimes a cloth rubbing against plastic will do the trick). The electrons (negative charge) collect on the cloth leaving the plastic with a positive charge.

Objects like to be at a neutral charge and will tend toward a neutral charge. Because it's a good electrical insulator, the electrons in other areas of the plastic do not migrate to the surface of the plastic to neutralize it. You mentioned that it's dry. The exposed surface of the plastic would normally eventually be neutralized by the water particles in the air. Because it's dry, this will take a much longer time.

Now, you come along. You have a nice, neutral charge on you because you are an alright conductor of electricity and you are in direct contact with the ground. You see the plastic and touch it. Once close enough, zap! You transfer electrons to the plastic evening the charge.

I may have missed a couple of points but that's generally what happens and why.

Those sheets of styrofoam used in home construction that have the reflective foil on one side can pack a startling pop when handling them (4' x 8' x 0.5"...sorry, still using English measures).

If you walk across a carpet on a cold dry winter day, and if you have a spark plug in your hand, and you touch the doorknob or a ground, will the jump gap show a spark? -Ed "There's more where that came from, but I can't find it" - Ed

In my line of work, stray currents and voltages have caused many a fatal ( or worse) accident. Simply pulling a sweater over ones head can generate upwards of 5000 volts ( static) ever seen a sock stick to a dryer ? Cottons are the least dangerous of the offenders, nylons and acetates are the worst. BTW I am certainly glad i am not YOUR cat ! Cheers !