Speaker 1: Welcome to tech Stuff, a production from I Heart Radio.
Speaker 1: Hey there, and welcome to tech Stuff. I'm your host,
Speaker 1: Jonathan Strickland. I'm an executive producer with I Heart Radio
Speaker 1: and I love all things tech and it is time
Speaker 1: for a classic episode of tech Stuff. This one published
Speaker 1: way back on June eleven, two thousand four. It's a
Speaker 1: follow up to our last classic episode. This one is
Speaker 1: how carbon fiber works. If you listen to the previous one,
Speaker 1: it was the history of carbon fiber. Now we're going
Speaker 1: to get into more about what makes carbon fiber special.
Speaker 1: Hope you enjoy. Let's start really quick with a with
Speaker 1: a brief overview of what carbon fiber is um. It's
Speaker 1: it's made up of thin strands of crystalline carbon um,
Speaker 1: like like a really thin like human hair or thinner,
Speaker 1: that have been twisted into yarn type stuff and then
Speaker 1: woven into cloth type stuff and then usually treated with
Speaker 1: some kind of resin and molded into a final shape,
Speaker 1: right which it will then hold. So it's not you know,
Speaker 1: it's not like you put it in a shape and
Speaker 1: then like regular cloth that then loses that shape. You
Speaker 1: Actually that resin helps it hold that that particular shape.
Speaker 1: So that you end up with a really strong, really
Speaker 1: light material, right, And I forgot one step at the
Speaker 1: beginning there, which is you have to create a this.
Speaker 1: You have to create this carbonized material, right, This crystalline
Speaker 1: carbon strand um, which you do with stuff called a precursor,
Speaker 1: which can be made with it is most commonly made
Speaker 1: with ryan polyocryllum nitrial a K A PAN, which we're
Speaker 1: probably going to use more often than polyocrylla nitrial certainly
Speaker 1: I will um or petroleum pitch yep. So these precursor fibers,
Speaker 1: with the exception of petroleum pitch, this is all stuff
Speaker 1: that we are making synthetically. Uh, you know, we're creating polymers.
Speaker 1: Polymers are our long chain molecules. They're made up of monomers.
Speaker 1: A monomer think of that as like a basic unit
Speaker 1: of a polymer. So you get these really long chains
Speaker 1: and then we carbonize them. So how do we carbonize Well,
Speaker 1: for one thing, we use chemicals to alter the molecules
Speaker 1: in the fiber to create a perfect chain of carbon atoms.
Speaker 1: And these precursor fibers are pulled through an oxidation oven
Speaker 1: for a couple of minutes, and that oven's temperature is
Speaker 1: about two hundred fifty degrees celsius. So the fibers then
Speaker 1: take on oxygen atoms from the air while in the
Speaker 1: this oven. Now this is not the actual carbonization process here.
Speaker 1: This is just pre treatment, kind of like when you
Speaker 1: take your car in to get car washed, and this
Speaker 1: is the pre wash part of the wash. We should
Speaker 1: probably do an episode about car washes at some point
Speaker 1: and find out which one which of those stages are
Speaker 1: actually necessary. But getting back to the carbon fiber, the
Speaker 1: incorporation of oxygen atoms into the molecular structure of the
Speaker 1: fibers make the fibers actually resistant to high heat. It's
Speaker 1: very import because of an upcoming step. Now. At that time,
Speaker 1: the color of these precursor fibers changes as it oxidizes
Speaker 1: and eventually turns black. So whenever you hear something like
Speaker 1: carbon black, and yeah, it's that particular color. Like I
Speaker 1: remember this all the time in video games where you're
Speaker 1: choosing your like halo, particularly where you're choosing your armor colors,
Speaker 1: it's because it's taking it from the carbon fiber color
Speaker 1: and the color tends to be black because that's what
Speaker 1: happens through the oxidation phase. So next you put these
Speaker 1: oxidized fibers, the ones that have been tempered for high
Speaker 1: heat to go into another furnace, and this one has
Speaker 1: controlled amounts of other gases, but not oxygen, because you
Speaker 1: don't want the fibers to burn, right, because in the
Speaker 1: presence of oxygen, those fibers become fuel and then you
Speaker 1: just get fire, right, and then an ash is less strong. Yeah. Yeah,
Speaker 1: if you just burn up your material, you are not
Speaker 1: doing it right. So what you have to do is
Speaker 1: you have to have these other gases that can enter
Speaker 1: deuce other types of atoms into the molecular structure, for
Speaker 1: instance hydrogen perhaps, but non oxygen, so that way you
Speaker 1: don't actually have a fire, you don't end up burning
Speaker 1: the stuff, right. So, so with this tremendous heat, the
Speaker 1: the fibers vibrate and the atoms that are not carbon
Speaker 1: vibrate right out of this stuff, resulting in this carbonized
Speaker 1: material exactly. So we get these carbon atoms and they
Speaker 1: are becoming these tightly packed crystals that run parallel to
Speaker 1: the length of the fiber. The fibers then go through
Speaker 1: a bath of electrically charged water which etches the surface
Speaker 1: of the fibers. It actually carves into the surface of
Speaker 1: the fiber a little bit, and those etched surfaces create
Speaker 1: anchor points for resin. Yeah, because otherwise, you know, the
Speaker 1: resin wouldn't necessarily adhere evenly to the carbon fiber, making
Speaker 1: it less useful. This is a way of sort of
Speaker 1: giving those little hand holds. I think of it like
Speaker 1: a rock wall with the little handholds in them, similar
Speaker 1: to that. So net you have to spray the fibers
Speaker 1: with a light resin. Now that that is important for
Speaker 1: two reasons. It helps improve the fiber's material strength, and
Speaker 1: it creates a bonding agent for any future resin that
Speaker 1: would be applied to that carbon fiber. So this is
Speaker 1: not the stuff that makes carbon fiber uh adhere to
Speaker 1: a specific shape. It's not multiple right. This is just
Speaker 1: so that if you exactly if you want to apply
Speaker 1: multiple resin to it, that resin will adhere better. So
Speaker 1: everything here is all about pre treating this stuff so
Speaker 1: that it can eventually be put through whatever manufacturing process
Speaker 1: you want to continue down the road in order to
Speaker 1: get at whatever you're making, for example, a golf club,
Speaker 1: um or an airplane. Who knows you could do either
Speaker 1: with these sort of stuff. So then you have the
Speaker 1: finished carbon fiber, which is called a carbon fiber toe,
Speaker 1: and you wind that on a spool. So this is
Speaker 1: the stuff that other companies buy as raw material, which
Speaker 1: then they can braid, eve mold, or otherwise altered to
Speaker 1: make into their final product. Now, carbon fiber toes can
Speaker 1: also be grouped together in larger amounts called a web. Now,
Speaker 1: these webs can be put through a process that ends
Speaker 1: with a sheet of carbon fiber material. It's kind of cool.
Speaker 1: It looks like just an enormous black sheet of fabric,
Speaker 1: but that fabric is actually carbon fiber. So that fabric
Speaker 1: is five times stronger than steel and lighter than steel,
Speaker 1: and more more, it can be stiffer than steel if
Speaker 1: you apply the resin to it. I mean, it's it's
Speaker 1: interesting to think that something that looks like cloth could
Speaker 1: have these properties. Now, see the web is sandwich between
Speaker 1: sheets of paper to have a resin coating on them.
Speaker 1: Sounds familiar, right, got a lot of resin in this process.
Speaker 1: But these sheets are pulled through a high temperature pair
Speaker 1: of rollers. So think of the ringers we talked about
Speaker 1: with the washing machines, same sort of thing. You're putting
Speaker 1: this whole thing. Those those rollers are are at a
Speaker 1: high temperature. They're pressed together really tightly. And what this
Speaker 1: does is you get this protective layer over that that
Speaker 1: carbon fiber sheet, and then you remove the two pieces
Speaker 1: of paper. They just peel away because part of the
Speaker 1: material in there is kind of like a nose stick coating,
Speaker 1: sort of like teflon. And so you pull the paper
Speaker 1: away and you roll the the carbon fiber material, like
Speaker 1: the big sheet of material onto giant, giant spools. You
Speaker 1: do have to put a little polyvinyl coating on them
Speaker 1: so that way it's actually like to itself exactly. But
Speaker 1: they look like, and I am not the only one
Speaker 1: to have used this comparison enormous fruit roll ups, and
Speaker 1: like enormous fruit roll ups, they have that little plastic
Speaker 1: coating to keep it from sticking to it or fruit
Speaker 1: leather if you prefer, let's proprietarily yeah, um, but but yeah,
Speaker 1: that that that resin job there reminds me a lot
Speaker 1: of if you, as a child ever made ever preserved
Speaker 1: leaves or flowers and wax paper by by ironing it
Speaker 1: down so that so that you've got that thin layer
Speaker 1: of wax similar to similar, very similar. So now this
Speaker 1: entire process, Uh, does have some downsides to it. Not
Speaker 1: the flower pressing thing. No, no, no, no, carbon fiber
Speaker 1: if you're not careful, the flower pressing thing too. But no,
Speaker 1: I'm specifically talking about creating carbon fiber and not just
Speaker 1: the carbon fiber sheets. I'm just talking about the whole
Speaker 1: process of carbon fiber in general. One of those is
Speaker 1: that it tends to give off a lot of dangerous gases,
Speaker 1: including carbon monoxide. So the smokes and tars that are
Speaker 1: given off in this process are not necessarily poisonous, but
Speaker 1: can contribute to serious health issues with prolonged exposure. So
Speaker 1: one of the things that's really important in the facilities
Speaker 1: that make carbon fibers is that they have really good
Speaker 1: ventilation so that the people who work inside them don't
Speaker 1: get sick over time, sure, and really good collections so
Speaker 1: that you're not polluting the environment. Yeah, So this is
Speaker 1: a process that could potentially be harmful to the environment
Speaker 1: just through the production process. Now, we talked in the
Speaker 1: last podcast about how the fact that it's lighter and
Speaker 1: stronger than steel means that using it for vehicles means
Speaker 1: you use less fuel for that vehicle, which efficient. Yeah,
Speaker 1: and it makes it environmentally friendly from a fuel consumption process.
Speaker 1: But like all things, you have to look at the
Speaker 1: enormous picture, which you know. It's one of those things
Speaker 1: where every time I start getting really excited about technology,
Speaker 1: thinking oh, clean energy, and then I start looking beyond
Speaker 1: about how do you make the clean energy? And then
Speaker 1: I think, yeah, there needs to be a magic button.
Speaker 1: That's all I'm saying. But anyway, you you classify this
Speaker 1: stuff according to the tent sile modulus of the fiber
Speaker 1: tent file modulus. It's a measure of how stiff the
Speaker 1: fiber is. Yeah, but that's that's the term within the
Speaker 1: industry is tensile modulus. And I bet because because of
Speaker 1: the way the world works, there is both an English
Speaker 1: system and an international system for dealing with this. Yeah,
Speaker 1: you are absolutely correct. So the English them would be
Speaker 1: pounds of force per square inch of cross sectional area
Speaker 1: also known as p S I PI, and then the
Speaker 1: international system of units would be the PASCAL, which is
Speaker 1: also known as force per unit area. So one pascal
Speaker 1: is one newton of force per square meter, meaning that
Speaker 1: it is interesting to try and convert between the two. Fortunately,
Speaker 1: the the various sources we looked at spelled it all
Speaker 1: out for us, so we didn't have to see, we
Speaker 1: didn't have to do Yeah, we didn't have to worry
Speaker 1: about being the ones who messed up a conversion. So
Speaker 1: if these conversions are just let Google do that for me.
Speaker 1: Not the Google usually messes up conversion. If I mess
Speaker 1: up a conversion, it's because I accidentally didn't realize I
Speaker 1: put the wrong unit in on one side of the conversion.
Speaker 1: Uh So fortunately this case, we didn't have to worry
Speaker 1: about that. So low modulus carbon fiber have a tensile
Speaker 1: modulus below thirty four point eight million p s i
Speaker 1: or two hundred forty million k p a that's kilo pascals.
Speaker 1: And on the other end of the spectrum is the
Speaker 1: ultra high modulus. There's a tensile modulus of seventy two
Speaker 1: point five to one forty five million p s i
Speaker 1: or five hundred million to one billion kilo pascals. Now,
Speaker 1: in between those two extremes are levels like standard modulus,
Speaker 1: intermediate modulus, and high modulus. And if you wanted to
Speaker 1: compare it to steel, yeah, yeah, so for you know,
Speaker 1: for baseline comparison, right, because often that's what we like
Speaker 1: to look at right, carbon fiber versus steel. I mean,
Speaker 1: otherwise why use carbon fiber at all if steel were better.
Speaker 1: So steel has a tensile modulus of around twenty nine
Speaker 1: million p s i or two hundred million kilo pascals,
Speaker 1: so close, but but not even reaching the low modulus. Yeah. Yeah,
Speaker 1: the low modulus was thirty four point eight million p
Speaker 1: s i or two d forty million kilo pascals. So
Speaker 1: that means that if you go with the strongest carbon fibers,
Speaker 1: you get ten times the strength of steel, right, the
Speaker 1: tin style modulus if you want to be really picky,
Speaker 1: but yes, strength is how we usually call it. So
Speaker 1: steel is five times heavier than carbon fiber, and carbon
Speaker 1: fibers ten times stronger than steel. Yeah, if you're using
Speaker 1: the ultra high version. So that's pretty cool, and that
Speaker 1: is I mean again one of the big reasons why
Speaker 1: everyone is is really excited by this this particular type
Speaker 1: of material. Oh absolutely, but but okay, So aside from
Speaker 1: those pollution related drawbacks that we mentioned earlier, there are
Speaker 1: unfortunately some others with this material. We touched on them
Speaker 1: briefly in the previous episode, but let's go a little
Speaker 1: bit further into them. However, before we do so, let
Speaker 1: us take a quick break to thank our sponsor. I
Speaker 1: like saving the negative stuff for after the sponsor break.
Speaker 1: Let's talk about some drawbacks. All right. So we mentioned
Speaker 1: earlier in our first episode in fact, that carbon fiber
Speaker 1: is expensive, and we mean really expensive. It's like ten
Speaker 1: dollars a pound on the low end, whereas steel is
Speaker 1: something like a dollar per pound. Now we should say
Speaker 1: this is an improvement from twenty years ago. In right,
Speaker 1: carbon fiber back then cost a hundred and fifty bucks
Speaker 1: a pound, So the prices dropped precipitously, one might say,
Speaker 1: since the nineties, still more expensive than steel. Yeah, and
Speaker 1: and the price is because of that really intricate manufacturing
Speaker 1: process that we've just talked through. Um, the raw materials
Speaker 1: are more like four dollars per pound, which, to be fair,
Speaker 1: is still four times what steel costs. Yeah, I mean,
Speaker 1: you're you. And that's just to make those raw materials
Speaker 1: I mean, or by those raw materials before you put
Speaker 1: them through the carbon fiber process. So what exactly is
Speaker 1: making the process expensive? Okay? First off, those furnaces, uh,
Speaker 1: not the original furnaces, but the carbonization, right, they run
Speaker 1: around or even an excess of a thousand degrees celsius,
Speaker 1: which is over eighteen hundred degrees fahrenheit, meaning you've got
Speaker 1: a really big power bill. I always worry if I've
Speaker 1: let the oven on. Yeah, the process uses some five
Speaker 1: times more energy than steel production. Okay. Also, venting the
Speaker 1: waste materials safely is expensive. We talked about how carbon
Speaker 1: monoxide is one of the big things that's led out
Speaker 1: in this process, right right, Um, and weaving the stuff
Speaker 1: for maximum safety is expensive. You have to use a
Speaker 1: lot of fibers to compensate for for potential imperfections in
Speaker 1: the weave that could cause strain and eventual breakage within
Speaker 1: the fabric. Um. Also, it takes longer to create a
Speaker 1: piece than it does to just stamp out a piece
Speaker 1: of steel. You know. It's it's this huge three part process. Um.
Speaker 1: It takes an hour to cure the resin alone. So
Speaker 1: we're talking we're talking about bunches of time. Okay, But
Speaker 1: all right, I see here you actually looked more into
Speaker 1: the reson itself. I'm really interested in this process, right Okay.
Speaker 1: So if you make it with the most common resin,
Speaker 1: which is thermos set resin, it's in that shape forever. UM.
Speaker 1: It's it's really difficult to reef or melt down or
Speaker 1: recycle thermo set resin carbon fiber. UM. If you do
Speaker 1: try to recycle this stuff, that the resulting carbon fiber
Speaker 1: is weaker, it's too weak to be used, for example,
Speaker 1: in a car body for for safety standards. So there's
Speaker 1: greater potential for waste in both manufacturing and the post
Speaker 1: consumer market. I mean, if if you set this thing wrong,
Speaker 1: it's I mean you've basically just wasted this huge, expensive process.
Speaker 1: So if your molds are off even by a little bit,
Speaker 1: then you're you're stuck with the shape that you've got,
Speaker 1: and you can't easily break it down and just make
Speaker 1: a new one because it's going to be less strong.
Speaker 1: It'll be too weak to really possibly depending upon what
Speaker 1: the application was. Yeah. Yeah, so that that's a big draw. Yeah. UM.
Speaker 1: There are some possible solutions to this that the industry
Speaker 1: is looking into other than the manufacturing streamlining that Jonathan
Speaker 1: was talking about earlier. UM, and those are using strong
Speaker 1: acrylics in place of carbon fibers, or perhaps in combination
Speaker 1: with carbon fibers. UM. They're experimenting with heating the stuff
Speaker 1: with plasma instead of the thermal furnaces that are currently
Speaker 1: in use. You know, I love plasma furnaces. They're pretty
Speaker 1: they're pretty cool. Not literally length about plasma furnaces, so
Speaker 1: um or or possibly using re multiple thermoplastic resins in
Speaker 1: place of the permanent thermoset resins that are currently in use.
Speaker 1: Now that's interesting. Now, obviously with that particular approach, you
Speaker 1: would have to make sure whatever application you are using,
Speaker 1: uh the carbon fiber for wasn't going to bring it
Speaker 1: into contact with temperatures too high. So obviously, like exactly
Speaker 1: that would be. That would be one where I think
Speaker 1: the permanent thermo set would definitely be the way to
Speaker 1: go because they undergo such extremes and temperature that anything
Speaker 1: that could potentially weaken the the structure would be a
Speaker 1: big negative for that particular application. Sure, one more downside
Speaker 1: before we get onto happier news though, Um, the a
Speaker 1: lot of the precursor materials are petroleum based and so
Speaker 1: you know which which obviously, petroleum is an expensive and
Speaker 1: non renewable resource unless you've got a few billion years
Speaker 1: to play with. Yeah, if you don't mind you know,
Speaker 1: stretching out your lifespan too. Beyond what is conceivable, then
Speaker 1: you're fine. But otherwise you could reach a point where
Speaker 1: in years we're gonna have the singularities. That's true, that's true.
Speaker 1: So I guess millions of years. I guess it's really millions,
Speaker 1: not billions of years. I apologize, guys, hundreds of millions
Speaker 1: of years. So it's fine. I was overstating things exaggeration
Speaker 1: in order to make a point. But but so researchers
Speaker 1: are looking into renewable precursors like lignant, which is a
Speaker 1: would by product that would be really useful. So it's
Speaker 1: kind of funny too, because in a way, it's look
Speaker 1: back to the earliest days of carbon fibers where we
Speaker 1: were using cotton and bamboo to create carbon fiber. Time
Speaker 1: for another quick break, and we'll be right back. Now.
Speaker 1: Let's talk about some of the other benefits when when
Speaker 1: you treat this carbon fiber with the right resin ends
Speaker 1: up being resistant to corrosives, which makes it an ideal
Speaker 1: material for pipes that tend to carry corrosive liquids, and
Speaker 1: their fatigue properties are better than any metal. So by
Speaker 1: having these pipes, you don't have to worry about them
Speaker 1: wearing out a quickly. They're not going to corrode based
Speaker 1: upon whatever materials moving through them, and they are themselves
Speaker 1: in nerts, so you don't have to worry about chemical
Speaker 1: reactions going on in there. So that would be one
Speaker 1: of the big benefits if we were able to make
Speaker 1: enough of it to be used in that kind of infrastructure. Sure. Also,
Speaker 1: that strength really is impressive. Formula one race cars are
Speaker 1: made all of carbon fiber. Well, I guess not all
Speaker 1: of carbon fiber. I mean, you know they've got pieces, right,
Speaker 1: but the body is uh, and that's more as a
Speaker 1: safety regulation than anything else. So so if we could
Speaker 1: bring down the cost of the manufacturer, it could potentially
Speaker 1: save lives. Sure yeah, yeah, you know, you end up
Speaker 1: making even basic car designs much stronger just by switching
Speaker 1: the materials they're made out of. And then, uh, something
Speaker 1: kind of cool that I read before we started, uh
Speaker 1: really getting into this podcast. It was just a neat
Speaker 1: little little news item, and uh, I encourage folks are
Speaker 1: interested to go and look up the Mark one three
Speaker 1: D printer. It's built as the world's first three D
Speaker 1: printer designed to print continuous carbon fiber. So it uses
Speaker 1: a process called composite filament fabrication or CFF, which embeds
Speaker 1: continuous strands of fibers in a thermoplastic matrix, So you
Speaker 1: could actually print carbon fiber pieces like you could print
Speaker 1: various components in carbon fiber, right with that thermoplastic that
Speaker 1: I was talking about being being remultiple and remultiple, And
Speaker 1: so you might be thinking, hey, how much would one
Speaker 1: of these things run me? So if you want to
Speaker 1: pre order one of these, because they don't they haven't
Speaker 1: been out on the market yet, you can pre order one.
Speaker 1: Uh the cost is a lowly four thousand nine dollars,
Speaker 1: which you know, printers really isn't that expensive. I mean,
Speaker 1: if you're looking at at three D printers that are
Speaker 1: printing in UH an a BS plastic, which is typically
Speaker 1: what other three D printers use, those tend to be
Speaker 1: less expensive, but ABS plastic is not as strong. In fact,
Speaker 1: the print of material materials are supposed to be up
Speaker 1: to twenty times stiffer and five times stronger than a
Speaker 1: BS plastic parts. So if you are building things that
Speaker 1: have a lot of wear to them over time, this
Speaker 1: could be a good solution because it means you don't
Speaker 1: have to print replacements as frequently. Sure, although I mean
Speaker 1: I imagine that the cash to purchase the materials to
Speaker 1: put into your printer. Yeah, it might be more expensive
Speaker 1: to get the actual like quote unquote the toner than
Speaker 1: a BS, So that is something else to take into consideration.
Speaker 1: But yeah, so this material has has a huge amount
Speaker 1: of current use and future promise. Yeah. In fact, I
Speaker 1: remember some people even going so far as to look
Speaker 1: into the use of carbon fibers as a potential tether
Speaker 1: material for space elevator. But as it turns out when
Speaker 1: you do the math, it looks like, uh, carbon fibers
Speaker 1: wouldn't be strong enough. It wouldn't have the tin stile
Speaker 1: strength to withstand the forces. Yeah, because it's not quite
Speaker 1: as strong as carbon nanotubes. I mean, the problem with
Speaker 1: carbon nano tubes being there that you know, you can't
Speaker 1: get them as long as you can carbon. Yeah, producing
Speaker 1: carbon nanotubes is a big problem right now. Like, while
Speaker 1: we're getting closer and closer to to really efficient means
Speaker 1: of making carbon fiber more plentiful due to the manufacturing
Speaker 1: process improvements over time, we're a long way with carbon nanotubes.
Speaker 1: I mean, we've seen some promising develop elements, but you
Speaker 1: know it's still gonna be a while. I hope you
Speaker 1: enjoyed that classic episode of tech Stuff. We're going to
Speaker 1: uh take another look at carbon fiber soon. I think
Speaker 1: I was considering it earlier. I think I'm pretty firm
Speaker 1: on that. If you have suggestions for things I should
Speaker 1: tackle in future episodes of tech Stuff, reach out to me.
Speaker 1: The best way to do that is over on Twitter.
Speaker 1: The handle for the show is text Stuff H s
Speaker 1: W and I'll talk to you again really soon. Text
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