SACRIFICIAL PLASTIC DEFORMATION

CONVERTING ENERGY FROM AN IMPACT

With Koroyd, energy from an impact is converted through plastic deformation,
a little bit of heat and a little bit of noise. Read on to learn more.

LARGE COMPRESSION VOLUME

Koroyd can use up to 78% of the material’s thickness for maximum energy absorption.

Because of this large compression volume, the structure can endure multiple impacts within one accident and still have material left to absorb energy. 

For example, if you crash and roll on rocks, roots or tarmac, your head may hit the ground multiple times.

Important to note, after one accident involving a head impact, your Koroyd helmet (or any helmet) should be replaced and not used again.

FOAM IS LESS EFFECTIVE

Traditional materials stiffen during compression and solidify when up to 60% of the material is compressed, therefore reducing the thickness of the liner that can be utilised to absorb energy in an impact. This can result in forces being transferred to the head and brain.

EPS Foam Liner Oblique
Mountain Biker Crashing

THE RISK OF REBOUND

Koroyd has significantly less elasticity than EPS foam (expanded polystyrene).

For sacrificial energy-absorbing materials, a lower elasticity may correlate with a lower risk of injury.

When the initial compression of any energy-absorbing material is unloaded (after an impact), it gives back a bit of energy due to elastic behaviour (rebound).

So even after an energy absorber has fully compressed to the point of densification, the absorbed energy can still pose a risk to the helmet wearer. This risk is greater with EPS foam.

TECH TAKEAWAYS

PLASTIC DEFORMATION

With Koroyd, energy from an impact is converted through plastic deformation, a little bit of heat and a little bit of noise.

MINIMAL REBOUND

Because Koroyd has less elasticity compared to EPS foam, there is less risk of a second pulse from the energy absorbed during the loading phase (less rebound).

Koroyd Full Liner

LARGE COMPRESSION VOLUME

Koroyd can use up to 78% of the material thickness to absorb energy from an impact.

EPS FOAM LIMITATIONS

EPS foam densifies when around 60% of the material thickness is compressed, limiting its performance and potentially resulting in more energy being transferred to the head and brain.