Both flat rounded of socium silicate perlite insulation
Expanded Perlite granules can be bonded to form rigid shapes for a very wide range of applications. The most suitable binder for many purposes is a liquid sodium silicate similar to traditional “water glass.” The liquid sodium silicates are solutions of water soluble glasses manufactured from varied proportions of Na2C03 and SiO2, providing a wide range of chemical and physical properties.
Sodium silicates are widely used as high temperature adhesives and binders due to the following properties:
- Low Cost
- Easy to Handle
- Rapid Controlled Set
- High Strength
- Insolubility (when aired)
- Chemical Stability
Silicate-bonded Perlite makes an insulation material which is completely non-flammable, the refractory nature of the bond being a major advantage.
Potassium silicate is sometimes preferred for applications where heat insulation and fire resistance are the main objectives. This material has a slightly higher softening point than its sodium counterpart.
Sodium silicate is widely used as a binder for molding sand in foundries. The technology for Perlite/sodium silicate composite manufacture is based largely on this foundry industry experience.