PU foam (polyurethane) is created in a basic chemical reaction of a Polyol and Isocyanate, and the final product is determined by the addition of other chemicals but also by the actual polyol type determines the 2 basic family types.
- Polyether PU Foam (ether foam) – These tend to be the softest of grades and used in many retail and low cost applications. Densities range from 15 – 30 Kg/m³ as standard but others are available. The foams are prone to “blow holes” due to the foaming process.
- Polyester PU Foam (ester foam) – Mainly of improved physical properties, and controlled cell structure. Densities in general are from 20 – 60Kg/m³ Used where better performance is required and more technical characteristics.
PU foam is also known as Sponge, because early grades were developed that gave the look of Natural Sea Sponges, and are used for car sponges or bath sponges. AK Foamtech has the ability to create shapes from these grades for bespoke applications.
Compared to most foams, Flexible Polyurethane PU Foams are of low density with a variety of inbuilt properties designed for specific applications.
There are also some grades of sponge and foam that have been developed with Hydrophilic properties, used for absorbing water e.g. in the Pottery Industry for removing water from pots before firing.
Technical Grades exist, which are derivatives of the above 2 family types:
