Glassflakes are high aspect ratio platelets that impart isotropic reinforcement in contrast to fibres which typically give anisotropic reinforcement. This isotropic reinforcement is evidenced under a number of test regimes; from warpage evaluations to heat deflection temperature values. This change to the composite behaviour under strain is due to the high surface area of the glassflake used, restricting the free movement of polymer chains over the surface of the flakes. As glass flakes are synthetic with a controlled composition they have very low impurities - as such they are suitable for inclusion in materials for food contact and medical and dental applications.
All glassflake is available with silane surface treatments or 'sizings' - these are especially important for use in plastics where this aids in both the manufacturing process and end application. Similarly to other glass and mineral fillers, organo-functional silanes are used, providing a silicon end to bind to the glass surface and organic functional group to interact with the surrounding polymer chains. The silane is readily bonded to the glass flake surface aiding wet out, and facilitates dispersion in the polymer. The effect on physical properties will be determined by the degree of interaction between the silane, glass flake and polymer. E glassflake is also available in an agglomerated form, using an epoxy resinous binder to facilitate easier processing and handling.