Cardboard helmet
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That can't help but make me think of this video......
http://www.bikemag.com/videos/video-nope-not-all-helmets-are-equal/
http://www.bikemag.com/videos/video-nope-not-all-helmets-are-equal/
Why not plastic cardboard so sweat and rain would not be an issue?
http://www.alibaba.com/product-gs/554653777/Plastic_Polypropylene_PP_Cardboard.html?s=p
http://www.alibaba.com/product-gs/554653777/Plastic_Polypropylene_PP_Cardboard.html?s=p
yeah why not make something good for the environment out of an oil product oO
americans...
bad idea. corrugate yields under load in a much different manner than expanded foams do. corrugate doesn't deform under load until within about 5-10% of its maximum strength. up until that point it just transfers the load without absorbing any of it.
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that, and the fact that it is designed as ribs is another major flaw. the point of a helmet is to dissipate and absorb impact force. by using ribs instead of a vented shell, you're drastically decreasing the surface area, which in turn concentrates the impact force in the areas of contact.
You act like a friggin' expert on cardboard. As if......PFffffftttt!
You know I'm a package engineer right?You act like a friggin' expert on cardboard. As if......PFffffftttt!
Is that what you say to all the guys?You know I'm a package engineer right?
If you are actually dumb enough to buy that you might as well sh!t in your hands and clap.
What about bubble wrap? Packing peanuts?
Perhaps a empty bucket and a can of expanding spray foam insulation?
i prefer to just wear two beanies. if i am doing dh runs, then i wear a full face ski mask.
i just like the title of the thread...it sounds like a song title 
F'ing brilliant.
absolutely no oil was used in connection with the production of paper products. go make yourself a recycled soy organic hemp fair trade reclaimed paper hockey puck.
Am I actually about to just agree with something you've said..no....can't....do ...it...I'll just say I don't disagree instead..
I learned it from a book... you can agree with the book
Empirical data dude. Decades of it. It's why boxes are made of corrugate and the items inside it are cushioned with expanded foam, not the other way around.
And yes, not all my books are coloring books
It would be better the not deform until buckling begins from a head impact point of view. It is better to have a square wave deaccelleration verses time curve assuming limited distance because the peak deaccelleration is lower.
I'm sure the ribs are there to promote buckling. Other than that, I can't comment on the safety of this helmet without data. Is there something to keep it waterproof?
Indeed it would be useful to not expend any potential energy absorption until a certain deemed acceleration is reached for the skull, BUT, buckling is an unstable phenomenon, once it buckles, it offers almost no resisting force=no energy absorption.
So there'll be no energy absorption before it buckles (no movement, no energy expended), then it'll buckle during which there'll be a very quick transient in force, then it'll come right back up again as your skull bangs the inside of compacted cardboard while your still in the process of banging in to the ground.
What I'd really like to see is the acceleration/time graph from their tests, that's really what matters.
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I agree, I would like to see the graphs.
However, column buckling is one of the best methods of absorbing energy without mechanical storage of that energy. The absorber needs to be designed to continuously buckle rather than one buckle.
That's essentially what foam does I suppose, lots of local instabilities. A cardboard rib seems to just have a global buckling mode.
You won't get actual proper column buckling, the fluting doesn't function independently. It will buckle all at once, not continuously.
Also, let's not forget we're discussing a helmet designed by an art student
Which only illustrates the problems with the test standards.
Go try one out and report back to us, assuming you still have the cognitive function for speech.
part of the problem here is in the test standards. Current test standards were developed around the materials helmets have historically been made out of - expanded foams (which is a bit of a cart before the horse approach, but that's besides the point). The impact force testing focuses on meeting/exceeding a max spec (at least the test standards I've read), and pretty much ignore the min end of the spectrum. so the overall range isn't really being evaluated. they've been able to get away with it because expanded foams provide a pretty good range of impact force absorption, and by focusing on the upper end of the spectrum they're still providing a pretty good range of protection. not really the ideal way of evaluating things, but that's another discussion.
this creates an issue because you're using a test spec that was designed around one material (expanded foams) on another material (corrugated paperboard) which has drastically different physical characteristics. as was mentioned previously, corrugate yields under load in a much, much different manner - and only really yields within a small range of its maximum strength. so what its doing is creating a helmet that's only good for very high impact forces, and little else.
this creates an issue because you're using a test spec that was designed around one material (expanded foams) on another material (corrugated paperboard) which has drastically different physical characteristics. as was mentioned previously, corrugate yields under load in a much, much different manner - and only really yields within a small range of its maximum strength. so what its doing is creating a helmet that's only good for very high impact forces, and little else.
Every time I have "used" my helmets I have had local bruising and abrasions. The cardboard helmet seems to have some pads but during a crash that thing would chew your head up something awefull.
LOL So lots of head injuries eh?....... I'm beginning to understand now.
You've not noticed my Barbie in a box jokes over the years? I'm gonna need to be a little less subtle.You know I'm a package engineer right?
Try not to be so transparent with your jealousy.
I'd just assume not wearing a helmet over the false securities that this might give you.
...and how many of these can you buy before the ecological footprint has surpassed a standard helmet, considering that you'll be replacing this after every ride if you sweat.