You hear the crackling noise or may be even see some little bluish sparks when you pull off your clothes. Here is the explanation for the phenomenon and where else it occurs.
- Blue Sparks in the Environment
- Electrostatics And the Physics of Clothes
- How Do the Clothes Get Charged?
- Which Fabrics Release Sparks?
- Tips to Reduce Electrostatic Charging of Clothes
- How Alaskans Solve the Problem of Electrostatics
Blue Sparks in the Environment
Yesterday evening, we came home from dancing to a live band. I took my key out of my dance bag unlock the door. There it was again when the key touched the lock. The typical winter phenomenon of the little blue spark in dry cold weather in Alaska. This phenomenon sometimes even occurs when little twigs touch each other in calm wind. An electrical charge was released.
Now what has this quite normal event to do with fashion and style?
Electrostatics And the Physics of Clothes
On the first view nothing, but on second view a lot. The same phyical process makes any synthetic fabrics clinch. This physical law drives women loving and/or having to wear skirts/dresses despite of cold weather up the wall! Everyone using a dryer probably has come across some fabrics sticking to each other. When pulling them apart electrical charge is released. Well, let’s dwell down to the physics of these electric shocks.
The old Greeks already realized that some materials like to attract small, light particles after they have been rubbed. One of these materials, amber, they even gave the name electron (Greek ήλεκτρον). The materials, or in our case fabrics, act on each other by electrostatically induced forces between an electron and a proton.
This force is about 36 orders of magnitude larger than the gravity force!
How Do the Clothes Get Charged?
Rubbing two non-conductive fabrics can produce static electricity. This “rubbing” happens unintentionally between layers of clothes whenever you move. However, friction is not the only cause for build-up of static electricity. Two non-conductive fabrics also can become charged by being worn on top of each other. This means when you layer clothes for great style or in painfully cold weather.
What actually happens is that a charge builds up on the fabric due to the contact with the other fabric. Thus, a charge exchange occurs always when you separate the two fabrics that were in contact with each other. However, we only notice the effects of charge exchange (the little blue spark) when at least one of the fabrics has a huge resistance to electrical flow. Concretely speaking, the transfer of electrical charges from or to the hugely resistant fabric is on hold long enough for the effects of electrostatics to be audible and visible by little blue sparks.
It even may happen when you pull off a sweater!
When it happens, the charges remain on the fabric until they either discharge producing these sparks or are conducted to ground. In both cases, the charge is neutralized. Some people may also have a body chemistry that leads to an access of ions. That means they see the phenomenon more often than others.
In summary, the familiar phenomenon of the static ‘shock’ is nothing else than the discharge due to the neutralization of charge built up in the fabrics from contact with non-conductive fabrics. It is a natural law.
Which Fabrics Release Sparks?
Typically, winter fabrics like, for instance, tweed or a knitted wool sweater, have a relatively rough texture. Thus, charging through contact takes much longer than charging through friction among these fabrics. However, their rubbing on each other or on dry skin enhances the amount of adhesive contact between them or between them and the skin.
Here a list of clothing material that tend to clinch, i.e. get charged:
- Fine spun wool with no rough texture
Other materials that releases sparks are human hair, paper, lead, aluminium and dry human skin.
When you kiss your significant other in Alaska on a dry 40 below freezing day without winds, it’s an electrical kiss.
Now what to do about potential annoying discharge? Insulators are materials that do not conduct electricity. They can generate and hold a surface charge. Thus, they rarely produce a charge imbalance. Examples are rubber, wood, or plastic. This means when wearing an insulating fabric the charge that is transferred during contact with another fabric, the charge stays on the respective fabric. Well, the above is the physical analysis and is not a perfect solution. While you can wear stylish rubber boots, plastic and/or wood clothing are only for commencement regalia from recycled plastic bottles and/or projects from art classes, respectively.
Of course, one cannot change physical laws.
However, one can try at least to minimize that their process occurs. Now translated into our fashion world the above advices for reduction mean:
- Moisturize your skin as fabrics rubbing against dry skin lead to charging.
- Wear cotton, coarse wool or even no underwear instead of silk or synthetic underwear to avoid issues.
- Watch your shoes soles as some synthetic rubber soles or synthetic heels generate a lot of static electricity. On dry cold days avoid wearing those shoes that you identified to cause sparks.
- Try to “discharge” by touching wood before you unlock the door/touch metal.
How Some Alaskans Solve the Problem of Electrostatics
Finally, something I never tested myself and never will test it as I consider it a big mess. Anyhow, the story is at least fun telling. And you deserve a laugh after being so brave reading through all the physics related to clothes and sparks.
One dry, cold 40 below winter day at a dance place, a dance girl friend (who was born and raised in Fairbanks) asked me, whether I have some skin lotion or hair spray. I looked quite irritated about these alternatives. She explained she wanted “to spread it over her pantyhose so the dress does not stick to it.” Unfortunately, nobody had lotion or hair spray (which I considered a hint that this method does not work).
As I said, I never tried her trick, and therefore do not recommend it. However, I have to admit that I had wished I had had lotion or hair spray for her. Just to see whether it really works. 🙂
Dransfeld, K., Kienle, P. 2021. Physik: II Physik. Elektrodynamik und Spezielle Relativitätstheorie. Oldenbourg, 7th Edition.
Photo: N. Mölders
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