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A Scientist’s Guide to Wrinkle-Free Clothes - Video học tiếng Anh
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A Scientist’s Guide to Wrinkle-Free Clothes
A Scientist’s Guide to Wrinkle-Free Clothes
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Phụ đề (180)
0:00
I hate ironing!
0:02
There! I said it!
0:03
The only reason I’m wearing this jacket today is because
0:05
the part of it that’s wrinkled is out of frame.
0:08
Sure, ironing gets the wrinkles out, and my clothes are nice and crisp afterwards.
0:11
But it also takes forever, and I’d really
0:14
rather just throw everything in the dryer and be done with it.
0:16
It turns out, a bunch of scientists feel the same way.
0:19
They’ve studied why your clothes end up wrinkled in the wash,
0:23
and exactly how to get them to come out less rumpled.
0:26
So here are some science-backed ways to help make looking sharp less of a pain.
0:31
[♪ INTRO]
0:34
On their long journey through the washer and dryer, there are a lot
0:37
of factors that determine how wrinkled your clothes will be.
0:40
And you might be tempted to start at the very beginning with detergent.
0:43
But don’t be fooled.
0:44
That’s not the solution.
0:45
I mean, detergent is a liquid solution, but it won’t make your wrinkles go away.
0:50
Some scientists decided to measure whether it has any impact on how
0:53
wrinkled your clothes are when they come out of the washing machine.
0:57
In a 2003 study, researchers threw a bunch of fabric into a washing machine,
1:01
with and without detergent.
1:02
Then, when the cycle was done, they gave each fabric a score based on how wrinkly it was.
1:07
Technically, when they crunched the numbers, detergent made the fabric slightly more wrinkly.
1:13
But it was pretty hard to actually see that difference in the clothes themselves.
1:16
So if you were hoping that your detergent might help smooth things out,
1:20
that study might throw a wrinkle in your plans.
1:23
Speaking of liquids you might add to your washing machine,
1:26
fabric softener doesn’t seem to make much of a difference either.
1:29
Millennials everywhere, we can rest easy.
1:32
It might make your clothes feel softer and smoother when you put them on.
1:35
But its effect on wrinkles depends more on how the fabric dries.
1:39
In a different 2003 study, scientists washed clothes with fabric softener and
1:44
rated each item’s wrinkliness once it had finished drying.
1:48
Clothes that were washed with fabric softener and then tumble dried came
1:51
out slightly less rumpled than clothes washed and dried without fabric softener.
1:56
So technically it might help, but it didn’t turn out to be a significant difference.
2:00
Now, if the clothes were washed with fabric softener and then line dried,
2:05
they could come out more wrinkly than clothes washed without fabric softener.
2:10
Which is the opposite of what we’re going for!
2:11
Scientists aren’t sure exactly why this happens.
2:14
One possibility is that fabric softener might lock
2:16
in wrinkles because it’s usually added at the end of the wash cycle.
2:20
It comes in with the water that rinses out the detergent.
2:24
At that point, the fibers in the fabric are swollen with water and bunched together.
2:29
The fabric softener might coat the fabric in such a way that it
2:32
locks all the bunched-up fibers in a rigid shape.
2:35
That could set some of the wrinkles in the fabric.
2:37
And tumble drying might be able to knock out those wrinkles,
2:40
but line-dried items would be stuck with them.
2:43
On the whole, though, fabric softener isn’t going to do much about wrinkles either way.
2:47
The tumble-dried clothes were less wrinkly than line-dried clothes,
2:51
regardless of whether the wash cycle included fabric softener.
2:54
If you want neat clothes, you’re probably better off just chucking them in the dryer,
2:57
assuming they can handle it, than worrying about exactly how much fabric softener to use.
3:01
So detergent and fabric softener don’t really matter.
3:04
And neither does the material thickness.
3:06
Some types of fabrics wrinkle more or less than others, sure.
3:09
We’ll get to that in a minute.
3:10
But a 2017 publication demonstrated that when you’re considering two cotton fabrics, for
3:16
example, the thickness of that fabric doesn’t seem to make a big difference in how wrinkly it gets.
3:22
That’s true after both washing and drying.
3:24
But different fabric types do make a difference.
3:27
In a 2020 study, researchers found that knitted
3:30
fabrics almost always wrinkle less than woven fabrics after washing and drying.
3:35
This has to do with how much space the threads have in each material.
3:39
The yarn in knitted fabrics has more space to wiggle and
3:42
shift around than the threads in a more tightly woven fabric.
3:46
When fabric bumps around in the dryer, the yarn can settle back into its regular
3:50
layout and shake out some of the wrinkles that form in the washing machine.
3:54
It’s easier to knock those wrinkles out when the fibers have more freedom to move and adjust.
3:59
And that’s also going to depend on the chemical makeup of the fibers in a fabric.
4:03
As I mentioned earlier, being soaked with
4:05
water makes a difference in how wrinkly your clothes come out.
4:08
So cloth will wrinkle differently depending on whether its fibers attract or repel water.
4:13
Cotton fibers have an affinity for water.
4:15
They’re hydrophilic.
4:17
At the atomic scale, a cotton fiber has lots of
4:19
hydroxyl groups that each have an oxygen and a hydrogen atom.
4:23
This is similar enough to water, with its two hydrogens and an oxygen,
4:27
so that the two can comfortably mix and mingle with each other.
4:30
So, in the washing machine, when cotton fibers absorb water and swell up,
4:34
their hydrogen atoms can form hydrogen bonds with oxygen atoms in water or another fiber.
4:40
And vice versa.
4:41
Once the fabric starts drying and all the water gets pulled out,
4:44
the fibers can only hydrogen bond with each other.
4:48
If the fabric is all bunched up, those new bonds can lock in wrinkles.
4:52
So generally, hydrophilic fabrics like cotton tend
4:55
to come out wrinklier after several washes than they did after the very first wash.
5:01
But those hydrogen bonds aren’t permanent.
5:03
Heat and the mechanical action of flopping around in the tumble dryer can
5:07
knock some of those wrinkles back into that original smooth surface where they belong.
5:12
And some synthetic fibers, like polyester,
5:15
don’t grab onto water the same way because they’re hydrophobic.
5:19
That means they tend to wrinkle less when you wash them.
5:22
But that doesn’t mean they don’t wrinkle at all.
5:24
Once you heat up polyester fibers enough,
5:26
the individual chemical chains that make up that polyester get a little loose and bendy.
5:31
They’re too tangled up with each other to fully melt, luckily for your shirt.
5:34
But they can bend and shift and rearrange, much like the hydrogen bonds in your cotton clothes.
5:40
For polyester, this will happen between 67 and 81 degrees Celsius.
5:44
So if your dryer gets hotter than that, the molecules in your shirt get a little wiggly.
5:49
And once your clothes cool down, that rearrangement might leave some wrinkles behind.
5:53
But, regardless of the fabric, there are ways to prevent wrinkles before they even form.
5:58
And before I get into those ways, it’s time for an ad break.
6:01
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Some clothes come with a wrinkle-free treatment already applied.
6:55
That way, you don’t have to think too hard about how you’re washing and drying them.
6:58
Wrinkle-free treatments have been around since the 1950s.
7:01
Typically, a resin and a softener are applied to your garment before it hits the shelves.
7:06
That prevents the fabric from shrinking and keeps the fibers from squishing together.
7:09
As with knitted fabric, when the fibers have room to move around and
7:13
return to their original shape in the dryer, they’re less likely to wrinkle.
7:16
The wrinkle-free treatments work … at least for a while.
7:20
But they don’t last forever.
7:21
The more clothes are washed, the more they lose those softeners.
7:25
You can start to see these effects in just 4 washes.
7:27
One study from 2002 found that fabrics got stiffer and less stretchy as the treatment wore off.
7:33
Pretty much exactly what you’d expect now that you know the chemistry.
7:35
Since wrinkle-free treatments aren’t a forever solution, here’s some other things to try.
7:40
One study published in 2017 suggests that doing a bigger load of laundry can lead to more wrinkles.
7:46
Which…look, I get it.
7:47
I don’t want to spend my whole day doing laundry either.
7:50
It’s super tempting to try to cram everything into one load and then go do something else.
7:55
But your clothes might come out more rumpled for it.
7:58
As clothes bump around against the washing machine and each other, they get more and more wrinkled.
8:02
So the more stuff there is to bump into, the more likely you’re going to end up with wrinkles.
8:06
Those researchers found that filling your washing machine
8:09
even halfway spit out some fairly wrinkled cotton.
8:12
That said, tumble drying can knock out some of those wrinkles.
8:15
So maybe you’ll be okay with sticking a few extra shirts
8:18
in there if you’re not line drying your clothes.
8:20
And there are still a few other things you can do
8:22
to minimize how much your clothes are bumping around in the wash.
8:26
Like, a slower or gentler washing cycle could help smooth things out.
8:30
Research has shown that as a washing machine drum rotates faster, it applies more force
8:35
to the fabrics inside, which bends them out of shape and makes them more wrinkly.
8:39
But spinning too slowly can make it hard to get all the detergent out of your clothes.
8:43
So you might want to weigh your options with this one.
8:45
Even the amount of water in your washing machine can make a difference.
8:48
The same study found that more water in the machine made clothes less wrinkly after a wash.
8:54
That extra water made the fabric less likely to bend and crinkle under stress.
8:58
Everyone’s washing machine is different.
9:00
But a 2013 study found that using 16 liters of water, which was on the upper end for
9:05
that machine, spit out less wrinkled linens than a load with just 12 liters of water.
9:10
But there are two parts to every laundry cycle.
9:12
The way you dry your clothes might be more influential in the end,
9:15
as far as wrinkles are concerned.
9:16
The reason tumble drying your clothes generally leaves them smoother than line
9:20
drying has to do with the combination of heat, steam, and mechanical action.
9:25
Together, they help relax the fibers and reset those hydrogen bonds we talked about earlier.
9:30
Based on limited data, it seems that the longer you dry them for,
9:33
the better, at least in terms of looking crisp.
9:35
The same 2003 study that looked at the effects of fabric softener found that
9:39
tumble drying clothes for 45 minutes left them smoother than after just 30 minutes.
9:45
Of course, even if you pay careful attention to your washing settings, your fabrics,
9:50
the care instructions, everything, you might still end up with a few wrinkles.
9:53
And let’s be real, those clothes are still wearable.
9:56
But your final hail mary if you really need to look crisp after forgetting a load of laundry
10:00
in the dryer are tried and true methods that you’ve probably tested in the laboratory of life.
10:06
Like throwing the clothes back in the dryer for a few minutes with a damp towel, steaming them,
10:10
or hanging them up in the bathroom while you take a nice, hot shower.
10:13
And if all else fails, you can always break out the old iron.
10:17
As much as I hate them, irons work.
10:20
[♪ OUTRO]
