BigDipper, thanks for that info: that's a lot longer than I would have guessed. It makes me think of the fact that composites have been used in aircraft for more than 30 years, and the applications are expanding.
You have the right idea. Plus, there is a safety comment written on the box every helmet comes in, "Caution! There are some impacts from which this helmet cannot protect you." Let's face it if you head on a Peterbilt tractor at 80 mph it doesn't matter what helmet you are wearing. Regarding penetrations Snell has a penetration test that uses a specific size ball end. If the rider runs into a spear point it won't matter. The compromise made by helmet manufacturers is the stuff that Lawers love to litigate. We were at a point where California, the largest motorcycle state in the USA almost could not get helmets at all. It is a fine line to walk between making a helmet that will absorb most impacts and one that is so large that the aerodynamic drag is so high that the rider can't use it for more than an hour. I commend the makers that are still willing to do it.
To return at least close to topic, I would love to see some of our new lightweight plastics used in helmets. perhaps as Chas mentioned molded with air spaces? The strength is already there, just a careful evaluation of characteristics is needed. Once a molded shell could be made to work correctly it would be able to be sold for much less that fiberglass or carbon fiber which requires a lot of hand work.
I think I get what you're saying, BillFZ1. The styrofoam absorbs some of the impact. Thus the impact is not all delivered to the head inside. I would imagine you run a risk of some objects benefiting from that construction and penetrating the helmet entirely. Apparently the greater risk is not allowing the styrofoam to take some of the impact.
Uniquity, thanks for sharing your experience. That sounds like a fastener design/assembly problem, not a parts material problem: the durability, etc. of the plastic the clips are made of, and perhaps also their design, has not been properly matched to the characteristics of the plastic parts they fasten. Some fastener companies I've spoken to are developing new fasteners for these new plastic components.
Regarding plastic headlight covers, I saw some new plastics at NPE aimed at solving that problem.
You are correct that I said that the helmets require some controlled crush. Motorcycle helmets are intended to be a single use item. The shell is designed to prevent penetration of a sharp object but not to stop it cold. The thing is you can make a shell that stops just about anything, but if it transfers ALL the energy to the user you will pass along a concussion. Protecting humans is a tough job, and protecting humans HEADS is the toughest job of all. The helmets have a styrofoam inner shell that crushes to slow the energy transfer to your head. The Snell Memorial Foundation is a firm started to improve helmet safety. They have a series of design specs considered to be the best in the industry. Many racing organizations require the use of only Snell approved helmets. While I haven't checked lately, (7 or 8 years), to my knowledge no non fiberglass shell helmet has yet been Snell approved.
@uniquity: That's a real reality check. It got me thinking about all the kids toys, small appliances, and other household items that now have injection molded parts that I have lying around my house in various states of disrepair or juryrigged to work. I certainly wouldn't want that to be the case for my car which costs me tens of thousands of dollars. That is a design issue that definitely needs to be addressed if this type of lightweighting produces cars that consumers (the non-fix-it types like me) are going to readily accept.
I can understand how plastics will save weight in cars. However, I am concerned about a problem I am already running into with plastic parts in cars. I have an 2009 Toyota Matrix, and a 2010 Mazda5. Both of them use lots of plastic. In trim parts inside the car, and outside items like bumper covers that actually go up into the body. These parts use molded in plastic clips to attach the parts together and to the body. I have had a number of the clips break or come apart from normal use. My choices have been to either spend a fair amount of money to buy new parts or do what I can to come up with ways of using the parts on hand with my own solutions. So far I have chosen to fix them myself. While it works, it is not always the nincest looking result.
My fear is that with even more plastic in cars this problem will get worse. Will the car designers take this into account and come up with stronger and more reliable connections? Plastic headlight lenses save weight, but they loose clarity over time and must be polished in order to have a safe level of lighting.
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