Poron is a protective foam product manufactured by Rogers Corporation (USA).
It’s made from a polyurethane (PU) foam and has the ability to absorb and dissipate a huge amount of energy during impacts. In fact, the harder you hit Poron, the harder it becomes. The same piece of Poron can be squished between your finger tips if you do it gently, like a camping mat, or it can deflect your hardest strike like a punch bag.
How does it do that? Well, frankly, the science is beyond us, but essentially it slows down the rate of energy travelling through it so that the force which you might hit it with in, say, a millisecond, is transferred through to the other side of it over a much longer time. This is achieved by the PU stiffening rapidly as it absorbs the energy, and softening again more slowly as it passes the energy onwards. It “holds” the energy as part of its physical change.
Poron has some advantages over other padding methods, and in particular that it doesn’t get thinner with prolonged use. Alternatives like EVA, Neoprene and Silicone all do suffer (especially in high temperatures).
Poron is used by many outdoor brands, including Outdoor Research, Giro, Bogs, Bauer and Fox.