EPS foam’s superior ability to absorb impact energy and its extreme light weight make it the best material for use in bicycle helmets and an excellent choice for protective safety devices such as child car seats and sports pads.
The physics of helmet safety and the protection delivered by EPS foam is not as simple as it might seem. EPS foam performs several functions in a crash that ultimately result in protecting the rider from serious physical harm. EPS foam’s ability to absorb energy is more accurately thought of as energy management. The laws of thermodynamics tell us that energy can neither be created nor destroyed. EPS foam used in safety devices converts, channels and dissipates crash energy, thus preventing the energy from reaching the brain or body.
Unlike other types of padding, EPS foam does not bounce back after a compressing impact. This actually provides greater protection than softer padding. When rubbery padding is compressed, the material bounces back and delivers energy to the very area which you were trying to protect. Although that nice soft padding may feel like it would protect you better, the spring of that bounce back re-delivers the impact energy to your body.
EPS foam is not only superior for helmets but also delivers these same protective functions when used in child safety seats and other protective safety devices. EPS foam remains the choice for most bike helmets because it performs well in hard impacts and it is light, cheap, durable in use, reliable to manufacture and easy to ventilate.