Microfiber cleaning cloths
by Chris Woodford. Last updated: July 15, 2019.
When people joke about "inventing a new mousetrap" or "reinventing the wheel", what they really mean is that most inventions do their jobs
pretty well. There's either little need to think of anything new or
little chance of coming up with anything better than we have already.
If all inventors believed that, we'd still be living in caves and
cooking buffalo stew on camp fires. Even the simplest things can often
be done better. Take cleaning, for example—a chore most of us love to
hate. Who'd have thought there'd be a better way to scrub things clean
than using good old soap and water? If you've tried the latest
microfiber cleaning cloths, you'll know that technology really can make
life easier. Not only are these cloths more hygienic, they avoid the
need for expensive (and often harmful) detergents and they get things
looking far cleaner in a lot less time. It's not magic—it's science.
Let's find out how these things work!
Photo: Microfiber ("microfibre" if you're British) is a selling point, so you'll see it prominently written on the packaging of any cloths made this way. However, as I explain in more detail below, there are huge variations
in the size of the fibers used in cloths that claim to be "microfiber"—and that makes a big difference
to how hygienically they clean. These cloths claim to have fibers 100 times smaller than a human hair, which isn't
particularly informative, because human hairs vary enormously in size. Fibers that big would probably put these cloths
into the "average" category.
Cleaning with soap and water
Photo: Some typical microfiber cleaning cloths. These are made by EnviroProducts Ltd and sold under the brand name e-cloth®; Norwex is another very well known brand—and there are many others. e-cloth and Norwex boast
the smallest microfibers, making them the most hygienic cloths (assuming, of course, that you keep them clean).
Water is pretty good at cleaning most
things all by itself. That's because its molecules have two very
different ends. They're electrically unbalanced, so they stick to all
kinds of things (including lumps of dirt) like tiny magnets and break
them apart. Water is sometimes called a universal solvent because it
can dissolve so many different things. Where water alone can't help,
you can turn to a detergent (a soapy
chemical that clings to dirt and grease, breaks it apart, and makes it
easier for water molecules to flush it away).
Many people don't like using detergents, however. They're expensive,
for one thing. Another problem is that they can cause allergic
reactions and skin complaints. Some people worry that overusing
detergents and cleaning agents—in an effort to make our homes cleaner
and more hygienic—is undermining the way our bodies' immune systems
naturally defend themselves against germs. Another complaint is that
detergents don't simply disappear into thin air. They contain chemicals
that flush down our drains into rivers and seas, where they gradually
build up and cause water pollution.
We might be making our homes cleaner, but we're making the environment
dirtier in the process. For all these reasons (and a few more), many
people would love to be able to clean their homes without
chemicals—and that's where microfiber cleaning cloths can help.
What's different about a microfiber cloth?
Photo: The microfibers in this cloth are too small to see. It looks just like a normal towel, but it works in a totally different way.
Suppose you want to clean a large, dirty wall as quickly and
thoroughly as you can. You could use a toothbrush, but it would take you
forever. So probably you'd opt to use the biggest brush with the most
bristles you can find. Now scale the problem down. If you want to clean
a worktop really well, what's the best thing to use? You can't use a
gigantic brush or even a huge cloth, but you can achieve the same
effect by using a cloth that packs more punch into the same cleaning
area. An ordinary cleaning cloth has fibers made of cotton or a
synthetic material such as nylon. You've seen pieces of cotton so you
know exactly how big the fibers are. But a microfiber cloth has far
more fibers and they're much smaller. If "many hands make light work",
so do many fingers—or many micro-fibers.
Photo: Closeup of a microfiber cloth. You still can't see the fibers, even at this magnification!
Why do smaller fibers clean better?
Microfibers are able to attach themselves to even the smallest, most microscopic dirt particles—ones that
normal cloth fibers (positively giant in comparison) crudely brush past. If forces
were visible, you'd be able to see that there are adhesive
forces (the forces of attraction) between microfibers and dirt. As you may have learned in school chemistry, these forces are called van der Waals forces after their discoverer, Nobel-prize winning Dutch chemist
Johannes Diderik van der Waals
(1837–1923). (Van der Waals forces explain why geckos can stick themselves to ceilings using zillions
of tiny hairs on their toes.) Although there is only a microscopic amount of van der Waals force between one microfiber and
any given dirt particle, remember that there are millions of microfibers in a cloth, so the overall sticking
effect is magnified dramatically. That's why dirt, dust, and other stuff can be
"hoovered up" by microfiber cloths. And it's also why you have to clean microfiber
cloths so very thoroughly after you've used them.
(Generally, it's best to boil a microfiber cloth in a saucepan and avoid washing it
with normal detergents. Follow the manufacturer's instructions if you're unsure what to do.)
Do microfiber cloths "wear out"?
Providing you keep them clean, good quality microfiber cloths will keep on cleaning hygienically.
One recent study of using cloths like this to reduce rates of hospital infection found that "re-usable cloth performance improved at 75 washes, and reduced after 150 washes, although, in most instances, performance after 150 washes was better than at first wash."
How microfiber cleaning cloths work
If you clean the traditional way, with soap and water, the molecules of the detergent you use (shown here with orange dots) stick to and break down the dirt and grime (brown blob). When you rinse with a wet cloth (red), the water molecules (blue dots) glued to its fibers stick to the detergent and wash it away with the dirt still attached. This is old-fashioned cleaning with
chemistry. Compared to a microfiber cloth, a normal cloth has relatively few fibers so it cleans in a hit-and-miss way. Dirt gets missed and detergent and water often get left behind on the surface you're cleaning.
If you use a microfiber cloth, there's no detergent involved whatsoever, so how is the dirt removed? Instead of detergent, we rely on millions more fibers (shown here as blue lines) that can sweep dirt away. The fibers are made of plastic and many of them attach themselves to each dirt speck with van van der Waals forces. Working as a team, many fibers apply powerful enough forces to dislodge the dirt (loosened with a small amount of water) and carry it away, leaving the surface naturally dirt-free. This is new-fangled cleaning with physics using nothing but the adhesive power of forces—cleaning mechanically and without chemicals. The dirt stays locked inside the cloth's fibers until you wash it in hot water, which makes the fibers uncurl slightly and release their dirty content.
How are microfiber cloths made?
Look on the packet that your cloth comes in and you'll probably find
it says the ingredients are 50 percent polyester and 50 percent
polyamide (another name for nylon). In other words, you have a mixture
of two plastics. The cloth is made by forcing the plastics through a
tiny pipe and heating them so they weave together. These fused fibers
are then split apart into microfibers 10–20 times smaller.
Chart: Average microfiber cloths can plausibly claim to be antibacterial; the best cloths can claim to remove some of the bigger viruses (though not the smallest ones). Please note that each of the items shown here has a range of different sizes (for example, human hairs range from roughly 50–200 microns), and I've picked a single representative value in each case.
Cloths describes as "microfiber" can vary widely in the size of the fibers they use and therefore
in their cleaning effectiveness. In average cloths, the fibers are 10–50 times thinner than a
human hair—so each one is only about 3–5 micrometers (three to five microns) in diameter
and about 50 times lighter than the fiber in a pair of stockings (0.3 denier compared to typical 15-denier nylon).
That's smaller than pollen grains (5–10 microns) or red blood cells (10–30 microns), roughly the same size as "typical" bacteria (1–5 microns is a good rule of thumb),
but still bigger than most viruses (which tend to be smaller than 0.5 microns).
Since microfibers can't effectively remove anything smaller than they are, it would be
accurate to describe average microfiber cloths as "antibacterial" or "antimicrobial," but
"antiviral" would be a more dubious claim. The best cloths can make this claim, however: Norwex and e-cloth, for example, boast that the fibers on their cloths are 1/200 the width of a human hair (around 0.33 microns), which would make them
effective for removing over 99 percent of bacteria and at least some viruses, although not 100 percent of them.
(One important side-note: microfiber cloths are still very definitely an example of microtechnology, not nanotechnology, because micron-sized fibers are 1000 nanometers wide.)
A number of recent studies have found benefits of using microfiber cloths (often combined with steam cleaning) to help minimize the spread of infections in hospitals and similar environments (see the section "Scholarly studies" in the references below).
What's the best way to use microfiber cloths?
Like a traditional cleaning cloth, you use them dry for dusting and very slightly wet
for more general cleaning, but you'll need to experiment!
The first time you use one, force of habit will probably make you soak it with water and add loads of soap
as well—both of which will reduce the cloth's effectiveness. I find
the best way to use these cloths is with as little water as possible.
If you're cleaning very dirty windows, for example, use a standard
cloth and soapy water to wash all the dirt off first. Then rinse them
thoroughly with clean water and use a rubber squeegee to get them almost dry,
and let them dry in the air for just a little longer.
At this point, with hardly any water remaining on the glass, polish over
with your microfiber cloth—and you'll be amazed at the smear-free,
sparkling finish. If your windows aren't too dirty to start with,
simply use the microfiber cloth by itself with a little water. You can
use microfiber cloths to clean virtually any hard surface. Try them on
your bathroom or kitchen surfaces and you'll be amazed at the results.
(Sorry to sound like a bad TV advertisement, but these things really
are good!) You'll literally hear things getting squeaky clean and shiny.
If microfiber cloths are so good, why aren't they more popular?
Photo: Household detergents: who really needs them?
Microfiber cloths are much more widely known and used in Europe than
in the United States, partly because that's where the market leading
brands originated (E-Cloth in the UK; Norwex in Norway).
The household chemicals market is worth tens
of billions of dollars to big chemical companies and the stores that
sell them; they have little or no incentive to get behind a simple
technology that undermines their costly products. Companies like this
have spent a fortune on advertising for several decades, happily
convincing most of us that we need to blast our homes with
industrial-strength cleaners in a never-ending war on germs. Is it any
wonder, then, that we're skeptical of "magic" microfiber cloths that
promise to get our homes hygienically clean with nothing but water?
If you're still doubtful, try one of these cloths for yourself. And
remember that what's cleaning your home isn't magic—it's science!