The Secret Life of Swiffers

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This page last updated on 07/08/2017.

Copyright 2001-2017 by Russ Meyer


My Mother-in-Law discovered a product called "Swiffers."  Swiffers are an electrostatic dusting cloth.  She was impressed that they cleaned so well and asked how they worked.  I scrounged up a few facts on the web and thought about it for a while.  I figured out how they work and in the process stumbled upon an interesting, quiet field of technology concerning electrostatic fabrics.  Many common products used around the house are really rather advanced examples of modern technology.  We take it all for granted, but each of these products has a story to tell involving long hours of lab research, serendipitous discoveries, epic struggles to commercialize them, and even human drama.  This is a tale of but one of them.

How Swiffers Work
 
A swiffer is just one example of a class of electrostatic fabrics.  There are a number of these kinds of electrostatic cleaning cloths available...some are tougher, thicker, commercial grade type cleaning rags.  You can find them for sale all over the internet.  You could probably find one of the commercial kind at a professional janitorial supply store.

Most of these electrostatic cleaning cloths are made out of very tiny polyester fibers.  The fibers are either manufactured very, very thin or are normal diameter fibers that have been "brushed"...that is the ends of the fibers have been fractured (like frizzy hair or split ends), to make a bunch of tiny little fiberettes.  This results in a very soft feeling fabric...some say it's 10 times softer than silk, but I don't know how they measure "softness;" maybe they don't even measure it and it's just a subjective statement.  Anyway, the classic electrostatic fabric will be made like this.

The main claim to fame of these products is that they can dust a surface very effectively without solvents, chemicals, or water.  They rely on electrostatic forces to lift the dust off the surface being dusted.  When you rub the towel on the surface you are dusting, it develops a static charge...just like rubbing a balloon against cat fur or scrubbing your shoes over a carpet.  Dust particles near the cloth (like directly under it on the surface being dusted) are attracted to the static charge in the cloth, so they zip over and stick to it.  Because the cloth is made up of teeny-weeny fibers, there are lots of little convoluted holes and crevices for the dust particles to lodge in...so when the dust particles hit the cloth, they become mechanically wedged into the cloth itself.

Gory Details

Just in case you are a glutton for details, here are more...probably way more than you would have cared to have been burdened with.

These electrostatic fabrics are usually made out of polyester because polyester can pick up a static charge really easily.  It can do that because it has the ability to steal loose electrons from another material.  When it steals these electrons (through mechanical rubbing...you're actually rubbing electrons off the thing you're dusting), it acquires a negative charge; polyester is consequently referred to as an electronegative material because it gets negative when rubbed...hey, don't we all!  Anyway, the surface you just rubbed it on now has a positive charge and so do any dust particles on that surface.  The positively charged surface is attracted to the cloth, but it can't move any closer.  The dust particles can move so they do.  They have a net positive charge and are attracted to the negative charge on the fabric.  The cloth is made of polyester because polyester is more electronegative than most materials, it is cheap to produce, and it can be woven into a fabric.  The superfine polyester fibers also make it more efficient in generating negative charges.  That's because the fine fibers make more surface area that can come in contact with the other surface when rubbing to create a charge separation.

Electrostatic cleaning cloths are better at cleaning some materials than others.  It depends on the relative electrostatic characteristics of the two materials.  The cloths are much better at cleaning surfaces that are more electropositive than polyester.  It should do a horrible job on surfaces that are more electronegative than polyester.  Here's a list of things ranked in electrostatic order:

++++++++++++++++Very Electropositive  +++++++++++++++++++
Rabbit fur
Glass
Mica
Human Hair
Nylon
Wool
Fur
Lead
Silk
Aluminum
Paper
Cotton
Steel
Wood
=================   Neutral=================
Amber
Sealing Wax
Nickel, Copper, Brass, Silver
Gold, Platinum
Sulfur
Acetate, Rayon
Polyester     <--------  Our hero, polyester!
Celluloid
Silicon
Teflon
-------------------Very Electronegative -----------------

The electrostatic cloth should do really well on surfaces made out of stuff higher on the list than polyester.  The higher on the list the mo-betta it will be cleaned by the cloth.  Stuff below polyester won't get cleaned very well at all...in fact, the cloth might transfer some of the dust it has to the surface you're "cleaning.".  Fortunately, most furniture is not made of Teflon.

Electrostatic cloths should do well cleaning dry surfaces with fine dust on them.  They won't clean heavy dirt any better than an ordinary rag and solvent.  That's because the electrostatic forces involved are too weak to lift heavy particles of dirt.  So, these are meant for light cleaning...you know, little specks of dust.  The cloth won't work well on greasy or gunky stuff...in fact, that will probably permanently reduce the effectiveness of the cloth...that cloth is allergic to goo!  It should clean best when both the cloth itself and the surface being cleaned is dry.  If the cloth is wet, the moisture will interfere with its ability to develop an electrostatic charge.  The ability of the cloth to pick-up dust will also be affected by the relative humidity of the air.  If it's really humid, it will be harder for the polyester to develop a sufficient charge separation.

In theory, you should be able to wash the cloth in cool, clear water to clean it.  After it dries, it should be as good as new.  Be careful using soap, detergent, or anything like that to clean it though.  Those things might contain materials that would coat or stick to the polyester and literally gum up it's ability to generate electrostatic charges.  Eventually, the cloth will become contaminated with wax, polish, etc. from the surfaces you are cleaning.  If you can't get that stuff out of the cloth, it'll eventually goof it up.  One particularly lethal electrostatic cloth killer should be anti-static dryer sheets.  These things work by releasing a heat activated chemical in the dryer.  That chemical is supposed to apply a static inhibiting coating the fabrics in the dryer.  It will terminate a Swiffer with extreme prejudice!

Another thing to avoid is heat.  The glass transition temperature of woven polyester fabrics is 175 Fahrenheit.  So, if you get the cloth near this temperature, those little microfibers in the cloth will begin to melt.  That will reduce the efficiency of the cloth in generating static charge.  Tumbling it in a dryer could get it hot enough to mess it up.  Ironing definitely could get it hot enough.

Well, if you've read this far, I've got hand it to you...you're a real trooper!  I find all this stuff really interesting, but most people just roll their eyes in disgust.  It's OK, 40 years of it has hardened me...I can take it!