There are two main types of polyurethane: polyester and polyether. Both are highly effective in a diverse range of industries. Polyester urethane and polyether urethane are elastomers, meaning that they possess elastic properties, and both offer unique performance properties. What are the main differences between polyester and polyether urethanes?
Typically used in the softer urethanes, Polyesters have higher tensile strength and higher cut and tear resistance than polyether-based materials. Polyester has a high capacity for sliding abrasion resistance which makes it ideal for applications like scraper blades and chute liners. Typically the hardness of a polyester urethane is below 90A on the hardness scale, with “A” representing the rubbers. Polyester materials have poor resistance to moisture and have worse low temperature performance than polyether materials.
Moreover, Polyesters withstand high temperatures longer and are more resistant to heat aging. Compared with polyether, polyester is more resistant to attack from these harsh chemicals. For the polyester tubing, the fluid is air.
Typically the harder urethanes (above 90A), polyether materials have better moisture resistance and dynamic properties for its excellent hydrolytic stability. Polyether offers excellent impingement abrasion resistance which makes it the choice for sandblast curtains and bumpers that get hit head-on. Another advantage need to be mentioned, Polyethers are much less susceptible to dynamic heat build up. That is why they are the choice for high speed rollers where the rapid flexing creates heat. They also have better low temperature properties.
However, polyether materials have less abrasion resistance and are more likely to tear. Proven applications involving polyether based urethanes include bearings, idler rollers, elevator wheels and sprockets. For the polyether tubing, the fluid can be air and water.