Grocery Stores - Malls - etc.
July 1, 2010
Fowler Associates, Inc.
this may sound minor and not even just a TN situation, but I need
to know if anyone has advice on how to prevent static electricity
from getting me every time I touch metal. I came from FL, where
humidity is high and didn't have a problem. Now, with the cooler
weather and low humidity, I am almost in pain just going to the
grocery store picking up canned goods! Forget about opening the
milk case. I did hear that putting a dryer sheet in your pocket
may help. Is this true? Any suggestions would be welcome. It hurts!!"
This is typical of the comments
about static electric shocks. Look over the links on the bottom
of this page for more information on the problem.
The problem is simple:
1. The problem is Triboelectric
2. The static generation is from the
insulative wheels rolling on an insulative floor. Typically a new
store with new carts cause the most problems.
3. The electrostatic charge is accumulated
on the wheels inducing a high electric potential on the cart. If
there is a platic handle on the cart, this potential is induced
on the person. If there is no plastic hanle or if the person is
touching the cart, the high potential is conducted to the person.
In any case the person and the cart rise to high electric potential.
4. This potential causes a painful
or annoying spark discharge when the person touches the metal of
the food racks or the product such as canned vegitables. It is like
walking across a carpet and touching a metal door knob. ZAP!
Lack of grounding of the store and
racks is not the problem. In fact it is the grounding of the metal
in the store that makes the energy of the discharge higher. It has
a very low resistive path to ground of the discharge from the person.
This problem can be reduced by the cart manufacturer by making the
wheels conductive with carbon loading or conductive fibers. Many
manufacturers either do not know this or do not want to add the
stores have fairly successfully made attempts to solve the problem
by adding drag wires on the carts.click here for the article
These wires work by the principle
of passive ionization - described below. If the store where you
are shopping does not have the drag wires, you can add your own
using an aligator clip.
solution which has had some very good success is the use of conductive
threads in a bracelet form much like a "Friendship Bracelet".
This bracelet's fine conductive threads perform what is called Corona
ionization causes ions to flow from the charged person to ground
(treadmill) and discharge the person so gently that they do not
know it is happening.
These threads have very small points
which allow ions to flow freely as soon as the person reaches a
high potential from the triboelectric charging from the treadmill.
This picture shows how the bracelets
are worn. As the person walks and reaches for the a can of vegetables
she is discharged gently by the passive ionization bracelet.
Click on the following video for
a more detailed view. Bracelet
to properly use the static bracelet
The following video shows how the
bracelet works by Passive Corona Ionization. Notice the Van De Graff
generator charges and arcs repeatedly until the bracelet is held
close to it. The arcs cease during the time the bracelet is near
the dome. This is because it is drawing ions from the Van de Graff
by corona ionization unfelt by the wearer. It seems like magic but
in fact it is real physics.
de Graff and Static Friendship Bracelet
The bracelet can be fabricated using Static String** or any highly
Anyone can make such a bracelet if
they have highly conductive string such as from Static
To place an order for a bracelet,
please contact Anti Static Bracelets & Accessories at: www.antistaticbracelets.com
*Static Friendship Bracelet" is
a trademark of the ESD Journal and Fowler Associates, Inc. Patent
** Static String is a trademark of Stop Static