Polyurethane Hardness and Resilience
Polyurethane elastomers can be formulated to cover a wide hardness range, from 30 Shore A to 85 Shore D. The D scale is used to measure hardnesses greater than 95 Shore A. Most rubbers fall between 30 and 80 on the A scale and structural plastics begin at 55 on the D scale. Special formulations of open cast polyurethane can be prepared with resilience values as low as 2% or as high as 75%. Many polyurethane elastomers maintain their resilience with changing temperatures far better than other rubbers through the range from 0 degrees C to 150 degrees C. The table below illustrates Polyurethane bridges the rubber-plastic hardness range and therefore is suitable for a wide variety of applications.