Learn more about helmets

Not just another pretty face...

All helmets are basically made the same way, a female mold is gel-coated with either a clear or colored gel-coat then fibers are layed into the female mold, resin is applied and the material rolled out to remove as much air as possible. The part is then left to cure at either room temperature or it's heated to accelerate the cure. Although this is a good way to make a lot of helmets pretty quickly it does not result in a shell that offers much in the way of structural integrity compared to a high-pressure laminate. This is where ACC differs from the rest.

When talking about laminate structure and materials related to non-pressure versus high pressure laminating, the difference is that using high pressure versus no pressure controls the laminate and its compaction. Compacting the fiber and injecting exactly the right amount of resin results in a shell that far exceeds the shell produced with no pressure. And having exactly the right amount of resin versus fiber controls laminate structure. This is called fiber volume. In the very best wet lay-up hand laminated helmet the best resin content versus fiber volume is 50%. This means there are 50% resin and 50% fiber. Resin really has no strength in comparison to the fiber. So you need to control the resin content to a minimum versus fiber. Basically the resin is there to keep the fibers in place

ACC uses a modified resin transfer system, this process involves basically the same process as the non-pressure laminate, a female mold is sprayed with gel coat, Multiple layers of fiber are put in the mold but then pressure is applied at 75psi inside the mold. Resin is then injected in exactly the right amount and the helmet is heated to cure. By injecting the resin we can achieve a 40% resin to 60% Fiber ratio, which is optimum for helmet shells. The result is a laminate that yields all the structural integrity that the materials were meant to have.

Now that you know about the process you may be asking what's the difference between Fiberglass, Carbon Fiber and Kevlar. Everyone knows basically what fiberglass is, extruded glass. 95% of all helmets are made from fiberglass be it mat (random fibers) or woven fabric. They are all basically the same. One key factor is fiberglass is cheap. When talking about DOT and non-DOT helmets they are all basically made from Fiberglass. The non-DOT helmets being made cheaply and without the aid of high pressure.

Carbon fiber is made by superheating an acrylic fiber yielding high strength to weight and high stiffness to weight properties. When engineered properly Carbon Fiber composites can achieve the strength and stiffness of metals at a significant weight savings, these two factors are key to the manufacture of a helmet.

Kevlar is made by dissolving a polymer in a solvent and extruding the fiber and then spinning. While Kevlar has properties similar to Carbon Fiber it lacks compressive strength. The combination of 50% Carbon Fiber and 50% Kevlar results in a laminate with flexural strength about three times that of Kevlar alone.

Below is a comparison of typical fiber properties of some of the materials we use.

All this may be a bit confusing but it's important for you the customer to know what we are trying to achieve in our Non-DOT and DOT certified helmets

By using Carbon/Kevlar and our high pressure laminating process we can produce a helmet shell with far superior strength to weight ratio. The stiffness (42.3 MSI) of Carbon Fiber being a contributing factor to that strength and weight based on its density (1.78(g/cc)

DOT helmets must pass a battery of tests, one being a penetration test. This test is passed in DOT helmets by putting an inch or more of Styrofoam in the helmet. This is why DOT helmets are so big. In our new DOT helmet we have formulated a foam liner material that passes this same test but is only 5/8" thick resulting in a much smaller helmet. This new liner is so good we have applied for a patent on it.

Most Non-DOT helmets have a very cheap headliner material for the liner. We use an energy absorbing foam called Ensolite for our liner, while still being comfortable it offers energy absorbing properties that headliner material does not. Resulting in a small but safe helmet.

Advanced Carbon Composites is a Custom Helmet Manufacturer. We build each helmet by hand - one at a time. No compromise is ever made in the quality of the helmet.

We at ACC hope that this explanation will aid you in selecting our product. If you have any questions please free to call and we will be happy to answer any questions you have.