Cardboard bike helmet better than plastic

June 9, 2011 7:43 AM

Kranium is a bike helmet that is made from cardboard and out performs the standard polystyrene-filled lids.
posted by jeffmac (41 comments total)

— unlike regular helmets which break on impact —

Bike helmets are designed to break on impact.
posted by nathancaswell at 7:44 AM on June 9, 2011 [9 favorites]

At least they look cooler than regular helm...

...oh wait.
posted by Defenestrator at 7:49 AM on June 9, 2011

So, umm, we're supposed to re-use helmets? No thanks!
posted by blue_beetle at 7:49 AM on June 9, 2011

I think this is an awesome idea. I think it does look cooler than a regular helmet, and would be nowhere near as hot and suffocating to wear, and looks like it would be cheaply replaceable. I hate the whole experience of bike helmets, but I would buy this one.
posted by limeonaire at 7:52 AM on June 9, 2011 [3 favorites]

So, I just mail my head in to have it scanned then? Perfect!
posted by orme at 7:53 AM on June 9, 2011 [2 favorites]

— unlike regular helmets which break on impact —

Bike helmets are designed to break on impact.

Right, but the point is that this one is engineered so it doesn't have to break on impact to be effective.
posted by limeonaire at 7:53 AM on June 9, 2011 [10 favorites]

I mostly just like the kurfluffle in the comment section of the linked page over what exactly "cardboard" and "corrugated" is.
posted by Windigo at 7:54 AM on June 9, 2011 [10 favorites]

Indeed, that's part of their design for absorbing the impact. Kranium helmets do, too, to a degree:

During a crash the force peak of the impact is absorbed by the ribs tending to flex and de-flex. The remaining amount of energy is then absorbed by the crumpling nature of the corrugated ribs.

blue_beetle: So, umm, we're supposed to re-use helmets? No thanks!

Not supposed to, but are able to. I figure it's more of a worst-case scenario type thing, though having your helmet utterly ruined by the impact is a greater incentive to replace it.

There is more information and design graphics on the Kranium site, including a picture of the template, giving you some idea of how much cardboard is used (it's only one of three or four sheets needed, counting the ribs on the helmet).
posted by filthy light thief at 7:56 AM on June 9, 2011

Also, think about this: This means helmets can now be made from mostly recycled materials, and may even be biodegradable to some degree over time. That's way better than the standard polystyrene and plastic.
posted by limeonaire at 7:58 AM on June 9, 2011 [5 favorites]

I've been wearing a cardboard hat for years, suffering all sorts of insults.

Perhaps my time has come. I hope so.
posted by TheAlarminglySwollenFinger at 7:58 AM on June 9, 2011 [12 favorites]

Could this be easily produced by a vending machine?
posted by Phalene at 8:03 AM on June 9, 2011

There seem to be some odd marketing claims in this project. For example

However, polystyrene does little to absorb impact energy but distributes it over the head.

A good polystyrene helmet should both absorb and distribute impact energy. Distributing impact energy is a good thing! The problem is that modern helmets have to trade off weight and ventilation with effective energy transferrence.

Furthermore, what is the point of the clear (acrylic?) or colored shells? They seem to reduce the airflow for what benefit? Just fashion?
posted by muddgirl at 8:04 AM on June 9, 2011 [3 favorites]

Also, if a single cardboard helmet is able to repeatedly meat safety standards it should protect from multiple impacts to the same location during the same accident, unlike regular helmets (if regular helmets indeed break upon impact).
posted by mapinduzi at 8:06 AM on June 9, 2011

if regular helmets indeed break upon impact

That's another odd marketing claim - polystyrene helmets work sort of like a solid airbag. Their purpose is to slow acceleration by providing a cushiony substance that deforms on impact. It's not that helmets "break" in the traditional sense of cracking or what-have-you - it's that material deformation is what they do, and once the material is deformed past a certain point it can't un-deform

Of course, the exact same thing is true for a cardboard helmet! The material may tolerate larger amounts of force before it is irreversibly deformed (and if it can accomplish this at a lower weight and with more ventilation, then that's a definite positive), but a cardboard helment "breaks" in the same way as a polystyrene one, as far as I can tell.
posted by muddgirl at 8:14 AM on June 9, 2011 [2 favorites]

meat safety standards?
posted by filthy light thief at 8:15 AM on June 9, 2011 [6 favorites]

Better than plastic. Worse for trees.
posted by punkfloyd at 8:17 AM on June 9, 2011 [1 favorite]

Furthermore, what is the point of the clear (acrylic?) or colored shells? They seem to reduce the airflow for what benefit? Just fashion?

So it would appear. They give none of the benefits of tin foil.
posted by The Bellman at 8:17 AM on June 9, 2011 [2 favorites]

This seems like it might actually work well in the testing lab. And maybe in the real world, too, at least until the "waterproof acrylic compound" protecting the cardboard cracks out of regular use/abuse or the manufacturing process misses one tiny spot in all of that surface area of corrugation. Then rain and/or sweat gets in there and suddenly you're wearing something on your head that has all the crashworthiness of the "Week In Review" section of the Sunday Times. (The cartoons, they do nothing!)

Also, factoring in the outer shell of plastic and all of the acrylics used to protect the cardboard, how much more recyclable is it really over a regular polystyrene skid lid?
posted by the painkiller at 8:20 AM on June 9, 2011 [3 favorites]

I'm a "spandex-wearing Lance ArmstrongRyder Hesjedal wannabe" and I'd wear one of these... not on my road bike though. I think the only reason a helmet like this is plausible now is because skater-style helmets with no ventilation are in vogue. Perhaps it'll take a bit more engineering for cardboard helmets, but high-end polystyrene helmets are a miracle of light weight and ventilation. Things you really appreciate grinding up huge hills in the summer time.

Still, around town? No reason why not.
posted by klanawa at 8:35 AM on June 9, 2011

Furthermore, what is the point of the clear (acrylic?) or colored shells? They seem to reduce the airflow for what benefit? Just fashion?

I sort of remember that years ago, when the plastic shells were becoming common on helmets, that they were supposed to be safer than the old ones of just polystyrene. The ideas was that plastic shells will slide on pavement, while the exposed foam will catch and add torsional force. I imagine it's the same with cardboard.
posted by hydrophonic at 8:35 AM on June 9, 2011 [2 favorites]

Yeah, I wonder about that issue. Bicycling helmets around the late 1980s often had removable spandex covers. I remember hearing that the covers should be left on so that in a sliding crash, the helmet wouldn't catch on a rough surface and cause a neck injury. I don't know if snagging like that ever caused any injuries, but this thing looks pretty prone to it.
posted by exogenous at 8:37 AM on June 9, 2011

Don't say it's made out of cardboard if you don't want "valkraider" to get all corrugated-knowledge-dropping on your ass. (see the comments below the Wired story).
posted by mr_crash_davis at 8:42 AM on June 9, 2011 [1 favorite]

So weird - what do they call corrugated aluminum or corrugated steel in the UK?
posted by muddgirl at 8:49 AM on June 9, 2011

A chazwuzzer.
posted by Threeway Handshake at 8:58 AM on June 9, 2011 [1 favorite]

Just fashion?

Just fashion? Did you say just fashion?

Fashion determines about 75 percent of what people do with bicycles. (And everything else you can buy.) If it isn't cool, if it isn't the latest style, if it won't put you one up on the other riders, it won't sell.
posted by pracowity at 9:16 AM on June 9, 2011

Nice, but I'll have a Hövding instead, thanks.
posted by urschrei at 9:49 AM on June 9, 2011 [3 favorites]

pracowity - didn't mean to demean fashion - I like fashion. I mean "just fashion" as in "fashion alone vs. a secondary function such as skid protection."
posted by muddgirl at 9:56 AM on June 9, 2011

This is one of those things where I am loathe to trust any "this is better than that" argument that depends on intuition or even controled tests rather than a big pile of real world data. There are t00 many seemingly small variables that can have a major effect when the rubber your head hits the road.
posted by Kid Charlemagne at 9:57 AM on June 9, 2011

didn't mean to demean fashion

I was just funnin.

Sort of. Because it's true.
posted by pracowity at 10:02 AM on June 9, 2011

Nothing better than getting to the office with a limp pile of sweaty cardboard on my head. And by nothing better, I mean nothing better at absorbing the impact of a crash.
posted by Barry B. Palindromer at 10:34 AM on June 9, 2011

haters gonna hate, players gonna wear cardboard hats.
posted by TheCoug at 11:07 AM on June 9, 2011

Furthermore, what is the point of the clear (acrylic?) or colored shells? They seem to reduce the airflow for what benefit? Just fashion?

maybe rain would turn the cardboard helmet into an mushy mess?
posted by troubles at 11:12 AM on June 9, 2011

It's sweat/rain resistant Barry B.

" What about rains and sweat? No problem. Surabhi’s helmets mix the cardboard with a “waterproof acrylic compound” which makes them just as rain-resistant as the helmet you have now. "
posted by Submiqent at 11:33 AM on June 9, 2011

What, you mean someone who spent a long time designing a bicycle helmet actually thought about making it moisture-resistant/water-proof? You mean that this person might not be an utterly irredeemable idiot?
posted by Mister_A at 12:34 PM on June 9, 2011 [1 favorite]

Because this is the internet. Everyone is an idiot.
posted by Mister_A at 12:35 PM on June 9, 2011 [1 favorite]

muddgirl writes "Furthermore, what is the point of the clear (acrylic?) or colored shells? They seem to reduce the airflow for what benefit? Just fashion?"

The shell helps protect against sliding damage and minor puncture damage. I think I'd rather go through a windshield with a shelled helmet than an open weave of cardboard.

I'd bet the open grid generates a lot of wind noise too.

The write up indicates that the helmet passes the standard testing but I wonder if that is an artifact of the testing process. Cause I can't see how an open grid can possibly result in equal point pressures compared to a nice flat piece of foam. The cardboard is going to concentrate the force at the webs whereas the foam spreads it more evenly to the skull. If the test only looks at the overall force delivered to the skull then the testing procedure might not be seeing the higher point loading.
posted by Mitheral at 12:47 PM on June 9, 2011

I bike a lot and sweat a lot so when I first saw cardboard I thought this had to be a joke, but if the acrylic is thick enough and doesn't crack then...

"Acrylic [has]... better impact strength, and better weatherablility than polystyrene"

Pure acrylic can be recycled, so can pure cardboard, but mixing them makes it AFAIK very unlikely to be recycled.

"Fibre-reinforced polymeric waste can be treated by pyrolysis" ... [alternatively] ... "Reprocessing of problematic plastic scrap ... by using mechanical methods like milling ... has been tried successfully"

So recycling post industrial fiber reinforced acrylic can be done, but post consumer recycling is a whole other ball game.

FWIW: Pyrolysis means you heat it up to beyond burning temperatures but without oxygen, and you get some some useful stuff out as well as some slag.
posted by ecco at 1:06 PM on June 9, 2011

ecco writes "'Acrylic [has]... better impact strength, and better weatherablility than polystyrene'"

It should be noted that ultimate strength is a fairly minor consideration when it comes to designing crash padding. By which I mean it's on the checklist so that your product is durable but one is much more concerned with how well a material absorbs shock rather than how much it resists damage. IE A plain 1/8th" steel shell formed to your skull would be very durable but would provide only puncture resistance in a crash, your brain would still experience the same gees and deceleration trauma from the impact as it would were you wearing no helmet.
posted by Mitheral at 1:21 PM on June 9, 2011

Yeah but a shiny metal helmet would look awesome.

I should have cut the impact strength part. I wanted to emphasize the weatherability. And making the helmet sweat proof means the helmet would be more plastic than cardboard. Making it a nightmare to recycle.
posted by ecco at 1:43 PM on June 9, 2011

The shell helps protect against sliding damage and minor puncture damage. I think I'd rather go through a windshield with a shelled helmet than an open weave of cardboard.

I agree, but it also reduces some of the benefits of the open-weave corrugated cardboard. I wonder if the impact tests were done with a full acrylic shell.
posted by muddgirl at 1:44 PM on June 9, 2011

Cool! Now I'll have a place to keep my bug collection.
posted by sneebler at 6:10 PM on June 9, 2011