Polyester polyurethane foam, commonly referred to as “Ester”, is another type of urethane foam manufactured from a different set of raw materials. While similar in appearance to Ether, the Ester foams are superior in several ways. Ester foams have much higher strength and stretch properties. Tensile strength, elongation and tear strength values for Ester can be twice the values of Ether foams. Ester foams are more abrasion resistant as well as more resistant to degradation from exposure to alcohols and hydrocarbons. However, they are hydrolysable, which means it will have an adverse effect with water over long periods of time, so in high-humidity or wet environments are not recommended.

Ester foams are used for medical and acoustical applications, as well as for gasketing and sealing. With the higher strength properties, Esters hold up to sewing and are widely used in clothing and other fashion accessories, as well as, make-up sponges in the cosmetic industry and for filtration applications.

Ester foam densities range from 1.3 LB/FT3 to 6 lb./FT3. They tend to be firmer than Ether foams of the same density.

Sterling has a long history as a supplier for Ester Urethane foams. We have many grades of Esters for commercial applications. We also carry popular pore sizes of reticulated Esters. Whether you need case inserts or filter foam, Sterling can recommend and supply the needed answers.


No job is too hard or too big for us. If it needs foam then we can make it and send it anywhere in the world.