Kranium Helmets with the Strength of Cardboard

Kranium helmet with carboard crush layer

Kranium helmet with carboard crush layer

Protecting your cranium is the goal of Kranium, a new technology developed for bicycle helmets where the crush layer between your head and the outer shell is constructed from interlocking corrugated cardboard ribs. Don't scoff, the material is extremely strong and the structure of the ribs was shown to absorb 4 times the impact energy as a standard cycling helmet. Unlike polystyrene which loses its effectiveness after one impact, the cardboard has been proven to pass impact tests 5 times in succession.

Another benefit is fit, where expanded polystyrene helmets must use all sorts of pads or straps to customize fit for each individual head, with this method, a user's head can be scanned and a custom template printed for the individual ribs that perfectly conform when assembled. A helmet that fits works far better than one that slides out of position when an impact occurs. Also, once scanned, if you do hit the helmet and want to replace the crush layer, the company can just replace the ribs for your custom helmet using the scanned measurements from the initial fitting.

Since the interlocking rib structure is very light, overall weight is held to a minimum.

Kranium helmet corrugated carboard crush layer

Kranium helmet corrugated carboard crush layer

Helmet technology seems to advance slowly; better aerodynamics, flashier graphics, faceshields easier to replace, but we've had polystyrene impact layers for quite a long time. Though this project is directed at bicycle helmets I see no reason it couldn't apply to some scooter or motorcycle helmets, too. Will any company look at this and adapt it for applications beyond bicycles?

A light shell, a cardboard layer for protection and a very light liner of some sort, with a nice graphic outer shell, no one will know the difference. No, it won't replace a $500 full face helmet, but it's far better than no helmet at all and maybe better than some currently out there. Interesting to think about.

Link: Kranium via Wired


    • MacKenzie says

      Point well taken regarding moisture. I would think that the most interesting thing about this design is the use of structure, not necessarily material, to provide the strength and shock resistance. No reason why the design could not be replicated in a less (H2O) absorbent material.


      • Paul Crowe - "The Kneeslider" says

        They make note on their site the cardboard is treated to make it waterproof.

  1. woolyhead says

    Large model airplanes have used cardboard for flying surfaces and fuselages…….thinned polyurethane varnish soaks in and provides waterproofing…..very cost effective for this prpose……

  2. B50 Jim says

    Good idea! Paper in all its forms has been used for a variety of purposes over the centuries; why not make helmet crush liners from it? Once the rider’s skull has been scanned and digitized, the company can send out any number of replacements for little cost. That way there would be no worries about degradation, as is common with traditional materials. Ride a month, replace your liner. Replace it before each race; why not? Once consumers got over the resistance to using cardboard, it would be a good seller. I predict eco-conscious bicycle riders will lead the charge on this, and motorcycle riders will follow in time.

  3. Dano says

    Corrugated is the proper terminology for this product. I know this as there are two companies here and there owners and managers get upset (and correct you) when their product is referred to as ‘cardboard’.
    They have used their product to make all sorts of items, ie. shipping pallets and a lot of packaging protection barriers, where poly foam isn’t allowed. These barriers are exactly like the product use here.

  4. todd says

    I would think any waterproofing additive would render this non-compostable. Still, anything that gets rid of polystyrene is a plus. This deserves some sort of design award. Hopefully it won’t cost more just because it’s a new idea.

    I was needing my head scanned anyway.


  5. Hawk says

    I can really see an application of this in motorcycle helmets but only if the existing helmet manufacturers get with the program. There is so much hype about MC helmets that just isn’t true. In most cases, a come-off means you fall from the seat to the road, perhaps 3 feet? The fact that the road may be passing you at a fair clip just means that the helmet needs to protect your noggin from bouncing on the pavement for a while.

    However, when you put your head against something solid, like a piece of concrete or an oncoming bumper, even the “best” thousand dollar hat can’t protect you from much more than a 10 mph impact. Remember, it’s not the speed, it’s the sudden stop that hurts.

    Polystyrene has a “one impact” life. This corrugated liner appears to have up to a five impact life. Pretty impressive!! Being light and good airflow will certainly improve the comfort level too. I think the problem will be selling the regulatory minions, who don’t ride, on the idea of “paper” helmets.

  6. GenWaylaid says

    I wonder if coroplast might be more suitable for higher-speed impacts? The structural arrangement seems to be more important than the material.

    I’ll bet there’s plenty of room to optimize the structure for better impact protection. They’re just using a simple square grid right now. Perhaps it should have multiple, progressively stiffer “crumple zones” in the front to handle faster impacts.

  7. Thure says

    Now where did I leave that exacto knife, I’m gonna make me one of those. As a matter of fact I’m in the market for a new helmet. Maybe I’ll just modify the old one. Seriously would like to see this in the market.

  8. JustThunkin says

    Missed points…
    1) In a motorcycle collision, the re-usability of the liner is rather moot. Having had my noggin spared on more than one occasion both on and off road, the helmet shell is almost always structurally unsound for further use.
    2) In a full face helmet, the wrap-around padding needs to give a bit when placing the helmet over the less than perfect shape of the human head. Or the helmet is just too loosely fitted for proper protection. The cardboard would need a better padding than found in a bicycle helmet to accommodate a proper fit and not crush from normal use.
    3) The technology for cutting the cardboard insert is not unique to this particular product, and not necessary for forming polystyrene. Interesting application and green product for the eco-bicyclist, however.
    4) Five (5) repeat uses for the impact liner? Hmmm, methinks the bike rider should perhaps be more concerned with improving riding skills unless performing in the X-game styled sports!
    But thanks to @Kneeslider for an interesting bit of “tech”.

    • Bjorn says

      Hey JustThunkin,

      I believe the 5 impacts would not necessarily be for 5 separate incidents, but for those big accidents when you go cartwheeling down the road/track with your head bouncing around like a pinball.
      I believe motorcycle helmets are tested in Australia to provide safe deceleration of the head during two impacts in the same place. The ability to survive these repeated impacts can mean the difference between walking away from an incident and a closed head injury (where your brain does the pinball thing inside your skull). So, a helmet that can continue to provide safe deceleration of your head for five impacts has got to be an improvement. You can’t predict whether you’ll need it in an incident, but it’s good to have.
      Your point about the liner is a good one; any liner would have to be well anchored and provide sufficient “give” to make for a proper fitting. Of course current liners do pretty much that anyway, so it would simply be a matter f an altered design to allow the liner to anchor to the ribbed corrugated medium.

  9. gildasd says

    Top of the range bicycle helmets use strips of fibre moulded into the polystyrene to maintain the helmet in one piece.
    With every generation we are getting more fiber and less polystyrene. So in fact, evolution is going in the direction of this “carboard” helmet. This is the logical development, skipping 10 years of slow evolution.

    • JustThunkin says

      I think you are confusing the outer shell construction with both the liner construction and the liner function.

      The shell needs the rigidity to resist cracking or penetration from the outside contact and stop any intrusion immediately. The liner needs the ability to absorb impact by allowing controlled compression (movement) to prevent that semi-solid mass inside the skull from turning to jelly from the same immediate shock.

      The cardboard construction can be made to perform both crush and structural rigidity…but not in the given configuration. It is nothing but rigidity with very little “absorption”. Far more important to the liner construction is the ability to sustain a controlled compression…quite the opposite of being able to be reused due to rigidity.

      The “sport activity rating” to which this lid was tested (British EN 1078) is a far cry from the very rigorous North American and European motorcycle certifications.

      You might also want to check the more detailed construction pictures @ . You’ll note that the sheer size and depth of the lattice frame structure is extremely deep to achieve even the “sport activity” rating. Using the same technique to construct anything that would pass DOT motorcycle standards would require a helmet twice the size, at least…regardless of weight, try pushing that mass through the air at highway speeds and then check in on your neck and upper back muscles.

      An advancement?? For eco friendly non-critical sport use, maybe. For serious consideration in the world of motor vehicles…well I guess that’s why it isn’t certified for such!

      It can either pass the DOT tests or not. And that has nothing to do with the mentality of politicians, and a lot to do about safety.

      • gildasd says

        For motorbikes, the lattice would probably be tighter and made of a fiber + resin (kevlar, boron, cellulose…), not just plain cardboard. Crash structures on combat helicopters are already done this way.

  10. Steve says

    . We could make the shell from paper mache, or maybe even mold it right on your head!
    Interseting concept. And it can be recycled when youre done with it!