Video 9szhjhO9epA

[00:00] How does a zipper actually work? Like, try to push down on a zipper from above, and it probably won't budge. But, you should just use the pull tab, suddenly, it's probably smooth.

[00:12] So, how does it do this? We've made more zippers than there are stars in the Milky Way. You probably used one ten times today without even noticing, but the only time you do is when one breaks. I'll show you what to do when this happens, but what is actually going on inside this thing?

[00:27] I mean, obviously, the teeth come together inside the slider, but it turns out there's a surprising amount of engineering to this thing. All this is too small to be on a real zipper, which is why we made this one.

[00:40] This is a video about the surprising genius of zippers. What is that? This is a device that basically started it off. The idea was just to take a bunch of hooks and eyes and try to put them together in some fashion to make them, quote, automatic, unquote.

[00:59] The hooks seemed very sharp. Like, I don't think I'd want this on my fly. No, no, oh, definitely not fair. By the 1800s, clothes were typically fastened using laces, buttons, brooches, and hooks and eyes.

[01:12] These got the job done, but they all shared the same flaw. If you had a series of these fasteners on a piece of clothing, well, you have to close them one by one. Most people were satisfied with the state of affairs, but one man, American engineer Whitcomb Justin, thought the world deserved something better.

[01:28] The idea, primarily, it appears to be that he would put them in shoes, and people who had to lie shops would be able to do it in one quick motion. So that was the device that he had in mind, and it didn't work.

[01:44] Johnson was a pretty bad inventor. Most of his patents had never got much traction, but he was a great salesman. In 1893, at the Chicago World's Fair, he presented this fastening device as the next big fan,

[01:57] claiming that in no time at all, this would replace buttons and laces, and not just on shoes, but on all sorts of garments. A few local investors actually believed it, so with their backing, the Universal Fastener Company was born.

[02:10] A decade later, the company managed to carve out a small niche, primarily selling its fasteners for women's skirts. A pull and it's done, said their ads. But that was a lie.

[02:22] Justin's fastener design was a mess. It jammed constantly. And because it was delicate and made from rust from steel, it actually had to be removed from the garment before you could wash it. So, literally unsewn from your skirt.

[02:35] Moreover, if a single hook and eye were out of place, the whole fastener became unstable. So, simply bend over, and the whole thing could pop open. Naturally, the Universal Costner Company had very few repeat customers, and they fell into debt.

[02:51] But in 1906, a new engineer joined the team. 25-year-old Gideon Stumbach, who had just moved to the U.S. from Sweden. Why does someone like Gideon Stumbach, with a good degree in electrical engineering, decide to join this failing company?

[03:07] Well, it's a great story. One of the managers at the company had an absolutely drop-dead gorgeous daughter. And that daughter came into the eye of Gideon Shumbach, and he was completely smitten.

[03:23] So he ends up working for the plastic manufacturer so that he can cozy up to that daughter, and they married. For the next few years, Shumbach made minor improvements to Jobson's hook and eye design,

[03:36] but none were ever enough to make the product truly functional. Then, soon after giving birth to a daughter, his wife, O'Vira, fell ill and died. And Sundback was absolutely devastated.

[03:49] So the dramatic tale is that he threw himself into his work at that point, out of biting the grief from the loss of his life. This dark period in his life led to a major breakthrough.

[04:02] Sundback realized that this was never going to work. So after years of tinkering, he submitted a patent of his own. This is a patent from 1914, but if you take a look, it is nearly identical to a zipper from today.

[04:19] Sundback's modern zipper starts with two rows of teeth. And the teeth are shaped so that they're wider at the end than the opening on the other side. sides, so if you try to push them together, it's pretty hard. Now this is especially true

[04:35] on a real side zipper, where it's practically impossible. But if I add this slider to the bottom and try pulling on the full tab here, suddenly it's effortless. So how does it do

[04:53] Well, I can remove the cover from the slider to reveal that it's just a Y-shaped cavity. That it See as you zip up the Y cavity tilts the teeth at just the right angle so that the tooth has enough space to slot into a tooth without bumping into the tooth above And as you zip down this wedge piece separates the teeth allowing you to unzip

[05:22] This results in one awkward design quirk. At the top, no zipper is ever fully zipped up because the wedge is always there and has to remain between the teeth. Now, Sunback's original design was a little different to this big guy.

[05:34] It sported rectangular teeth with a bump on the top called a nib, and an equivalently shaped indent on the bottom called a scoop. That way, when the teeth would align, each nib would fit neatly into its neighbor's scoop, forming a strong connection.

[05:50] But there was a problem. Even though Sunback had a new design and a patent, manufacturing a zipper like this in the 1910s was very impractical. Each of the tiny teeth needed to be precisely shaped for the fastener to work,

[06:04] but at the time, there were simply no tools around that could do this reliably. So he had to come up with some extraordinarily clever machinery that allowed him to automate the production of the shipper from the very beginning.

[06:18] Sunback's machine worked like this. It took Y-shaped wire made from a nickel alloy as an input. First, it sliced pieces off the wire to serve as individual teeth, and then it stamped the scoop and nib into each tooth.

[06:32] Finally, the machine would clamp the two arms of the Y-shape together onto a piece of fabric called a tape. This tape held all the teeth in place, and it was the part of the zipper that would later get stitched onto clothes and other products.

[06:46] Funback's machines worked wonders. Even in their earliest forms, they could already make 150 meters of zippers per day, and these zippers were incredibly strong. That's because for a tooth to become unpaired, it needs to get some distance between itself

[07:02] and its neighbors, enough for the nibs on either side to pop out. But since the machine spaced the teeth so precisely, there was simply no room for that to happen. Now you might think you could just stretch the zipper vertically to separate the teeth,

[07:14] but the zipper tape itself is made from strong, inelastic fabric. So even if the garment itself is stretchy, the teeth are connected to the tape which is designed not to stretch, so they won't come loose. But there is a way for this mechanism to fail.

[07:27] If even its single tooth falls off, well then its neighbors have enough space to come loose. And then their neighbors come loose, and this causes a cascading effect and the whole zipper pops open.

[07:39] This isn't something you have to worry about with buttons which can only fail one at a time. But even with this flop, some back supporters thought this patent was a goldmine. So the Universal Fastener Company decided to launch the product under their new name,

[07:54] The Hookless Hooker. They abandoned that name pretty quickly and decided to call it the Hookless Fastener instead. This new fastener was a successful product, but not a mainstream one. Its first applications were pretty niche.

[08:06] You'd find it on Moneyboats, essentially the scouting packs of the 1910s, as well as tobacco pouches and rubber boots. Now, those rubber boots were particularly important. They were manufactured by the B.S. Goodrich Company.

[08:19] When they got a hold of the device, they were convinced that, yes, This would give us a leg up on our competitors. We will introduce this automatic fastener, but we need a name for it. Then the company's president had an idea.

[08:33] Well, you know, it works really well. It's pretty nice. You can just sort of, you know, it just goes sort of zip when you're closing it and when you're opening it. So BFGoodrich came out in the early 1920s with their zipper boots.

[08:46] The boots were such a hit that the name zipper transcended the shoe and became the name for the fastener itself. Soon, consumers wanted the zipper on everything. By the 1930s, the Universal Fastener Company became very, very successful.

[09:02] They got a new name, too, Talon. Since their fasteners had a secure grip, it was kind of like the Talons of an Eagle. Talon's new zippers were way sturdier than Justin's for Canai designs, because their parts were way simpler.

[09:15] And they were also made out of rust-resistant nickel alloy instead of steel, which meant you could leave them on in the wash. By the way, if you are putting something with a zipper inside the washing machine, you should always zip it up.

[09:27] That will prevent the zipper from snagging on your other clothes, and will also protect the zipper itself. Now, even though zippers rapidly became popular, there was pushback among the older and more conservative consumers,

[09:39] especially about putting them on the fly, and urban legends began to spread. One of the most famous ones is the myth of the fellow who has come to his Beyonce's parents to dinner.

[09:51] He's seated down at the table. He looks down and realizes, oh my God, I haven't shipped up my fly. So he zips it up. But then when he gets up a few minutes later to leave the table, he has caught the tablecloth in the fly of his office

[10:05] and so ends up sending the entire table humbling after him as he gets up and leaves. I'm still a bit confused by, you know, Zippers are more expensive more temperamental than laces And anyways they become huge regardless of that well now you see the heart of the mystery the novelty of the zipper itself was something that

[10:29] took hold of people people wanted to be modern and it came to be closely identified with being modern i found it very interesting that looking at world war ii the zipper manufacturer in germany was one

[10:44] of the protected industries despite the fact that it used fairly precious metals metals that were very important for munitions and the like but the zippers were protected because they were

[10:56] closely identified with modern prosperity so the idea that if we can have zippers then everything must be okay but a more obvious reason for the zipper's popularity is that it's just so easy to

[11:09] How much quicker is a zipper than a series of buttons? I have a jacket that has both, so let's time it. Three, two, one.

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[12:39] So, I want to thank Hostinger for sponsoring this part of the video, and now back to zippers. Fast forward to today, SunBounce design is still the one we most associate with zippers. Besides the classic metal variant, which was sturdy and reliable,

[12:52] zippers also started being produced from plastic, which were cheaper and more flexible. But you'd probably be surprised to know that these two zipper types aren't the most common zipper in the world. In fact, the world's most popular zipper doesn't have teeth at all, and it's this thing.

[13:09] Okay, at first it just looks like other zippers, but if I pull out the threads, you can see that everything here is just a single weird piece of plastic. Imagine you have a coil of plastic that you somewhat flattened.

[13:21] You can mold the plastic such that one side of every loop bulges out more on the top and bottom. If you do this a second time with a second piece of plastic, you'll notice that you now have ridges that fit perfectly together, much like zipper teeth.

[13:35] Stitch these two coils onto fabric, then add a slider, and bam, you have a functional zipper. This is known as a coil zipper. It showed up around the 1940s as a cheap alternative to the original design,

[13:47] And now you can find it everywhere, especially on things like suitcases and backpacks, where the zipper needs flexibility to maneuver around corners. Coral zippers also have another benefit. Since all of their teeth are one interconnected piece of plastic,

[14:02] there's no way for a single tooth to fall off. So that itself cannot cause that cascading failure. But there was still a problem zippers had to solve, and that was that they were kind of too good.

[14:14] Especially zippers that have been used a lot and are kind of worn down in the slider, they can just unzip on their own. To prevent that, Gideon Stumback himself actually designed a locking mechanism, like a brake.

[14:27] Under the piece that connects the pull tab to the slider, there is a small metal pin. When the pull tab is in its typical resting position, one end of the pin sticks through a hole in the bottom face of the slider,

[14:39] lodging itself between the zipper's teeth or coil. That way, the slider is stuck in place. But when the pull tab is pulled forward, this releases the pin allowing the slider to move. Now you can see that there's like this little tiny gap through which you can see light and that's because the zipper stop is now engaged.

[14:57] But if I grab the pull tab and start pulling, you can see that because of the way that it's shaped, it's actually going to end up pushing that part up even though I'm pulling to the side and that's going to disengage.

[15:09] You can try to pull apart the flyer on your pants, but unless you actually grab the pull tab and pull it down, it is not going to open. These locking mechanisms aren't on every zipper, but they're more common than you might think. I counted out 65 zippers in this room in total.

[15:23] 33 of those 65 had stopping mechanisms, which is over 50%, which is also something I never noticed on a zipper But as I was hunting for zippers in my room I noticed something else From pull tab after pull tab there no mention of talent But I kept finding the same three letters instead

[15:41] YKK. YKK. YKK. YKK. Even on clothes and objects from completely different brands. If you look at your zipper now, you'll probably see the same thing. So, at first I thought this might refer to a particular style of zipper or something,

[15:55] but then I googled it, and it turns out that YKK is a company. the biggest zipper company in the world. If Talon has the original patent rights and they own the original zipper, how, how did I have a single Talon zipper in my room

[16:07] and how did YKK end up dominating the zipper world? Well, Talon pretty much ruled the zipper market until the 1930s, but in 1934, Sumbach's original patent expired,

[16:20] so the playing field was wide open to competitors. That same year, Japanese businessman Hadao Yoshida founded a new fastener company. the Yoshida Manufacturing Corporation, or YKK.

[16:33] It began as a single workshop in Tokyo where each zipper was made by hand. Then, in 1945, that workshop was completely destroyed by Allied bombs. But Yoshida was undaunted. He rebuilt the plant, and after the war, he started buying zipper-making machines from the U.S.

[16:49] They improved the machine, particularly they improved their speed. They then also decided to switch to manufacturing everything in-house, from the zippers themselves, to the machines, to even the boxes that the zippers were shipped in.

[17:02] And YKK emphasizes quality above everything else. So they make a real point of saying that if you have a YKK zipper, you can depend on it utterly. And that turned out to be an enormously successful sale tax.

[17:18] Around 1980, YKK surpassed Palin as the world's biggest zipper maker. And by the early 2000s, Talon's U.S. market share had fallen to a near 7%, while YKK had surged to around 45%.

[17:31] YKK surpassed the 10 billion annual zipper unit sales last year. I mean, that's a very impressive number. Like, 10 billion is crazy. It's equivalent to more than 3 million kilometers in length.

[17:45] It could be like around 18 tricks around the world. And not all of these are regular, everyday zippers either. So, this is an airtight, watertight zipper, and this relies on rigid metal-to-metal ceilings,

[17:59] where nickel teeth are forced tightly together against a rubber tape, providing an extreme pressure resistance. I mean, that looks like a mean zipper. What's an extreme use case for a zipper like this? Sea-speed diving, submarine escape suits, submarine escape suits sounds really cool.

[18:15] In case of an emergency evacuation of a submarine, you need a suit that can balloon up with air to counteract the pressure of the deep ocean, and that can provide buoyancy helping you shoot up to the surface. But you also need to be able to put it on super quickly,

[18:29] and the best option seems to be this suit with a giant watertight and airtight zipper on the front. Airtight zippers like these even made it onto space suits! And that's the zipper. It's this surprisingly genius invention that no one really asked for.

[18:44] I hate when this happens. I think the zipper's slider may get stuck in fabric, comes cold in the chain, so if dirt or dries and jersey in the zipper,

[19:00] the best fix is to carefully remove any trapped fabric or debris or move the slider gently. Okay, so carefully removing stuff from the zipper. Yeah. My first reaction was just like, you know, try and jarring them over the slider.

[19:15] You're saying I shouldn't do that. Yeah, no. Moving, definitely. Carefully. And if there isn't any visible debris causing the zipper to get stuck, you can try lubricating the area with graphite from a pencil in order to get the slider moving again,

[19:30] because it's a great dry lubricant. But probably the most annoying zipper problem is when a zipper unzips on both sides of the slider. This usually happens when the slider becomes worn or bent and can no longer apply enough pressure to properly interlock the zipper elements.

[19:46] As a result, the zipper chain separates behind the slider. A worn down slider is something you might be able to fix at home. Just take some pliers and crimp the slider together from the sides. That will make the inner cavity more narrow, just like when it was new, which should make it bring the teeth together again.

[20:02] Just don't crimp it too tightly. I just can't get over the fact that the first patent Gideon Sunback submitted was around 1914. And in those 112 years, you know, so many other devices that we've invented have been completely transformed, got better, got faster, cheaper.

[20:19] But it seems like the zipper is mostly, you know, mostly just the same. So it's just that Sunback's design was that good. It's that good. I don't have any better explanation. It really is just that good.

[20:32] I am really worried.