A material’s resistance to localized deformation
Polyurethane delivers excellent performance across a hardness range that spans from approximately athletic shoe sole (low hardness) to bowling ball (high hardness). Polyurethane’s hardness range straddles typical rubber and plastic hardnesses. Many applications – from shock absorbers to wheels to wear pads – take advantage of polyurethane’s unique combinations of performance and hardness.
Hardness is an indicator of a material’s modulus. But hardness alone is not a good specifier of a polyurethane’s overall performance. Different polyurethane formulations can have the same hardness, yet have a very different set of performance properties. So don’t rely on just hardness to specify a polyurethane.
Urethane’s hardness has a wide range from very soft, like a gel bicycle seat (~25 Shore OO), to very hard, like a bowling ball (~75 Shore D). But the sweet spot for many of its performance properties occurs from 55 Shore A to 75 Shore D.
Hardness vs Density vs Abrasion
| # | Product | Hardness | Density | Abrasion |
|---|---|---|---|---|
| 1 | PU Bumper 01 | 70 ShoreA | 300 kg/m3 | 250 – 300 mm3 |
| 2 | PU Bumper 01 | 70 ShoreA | 600 kg/m3 | 150 – 200 mm3 |
| 3 | PU Bumper 01 | 70 ShoreA | 1100 kg/m3 | < 50 mm3 |
