Glass Flakes

Glass Flakes are thin, platelet-shaped particles of chemically resistant glass produced by the controlled attrition or milling of glass formed into thin sheets or fibres. The resulting platelets have a very high aspect ratio, typically 50:1 to 200:1 for commercial grades, with individual flake thicknesses of 1 to 5 µm and diameters ranging from tens of micrometres to several millimetres depending on the grade.

The primary glass types used are C-glass (chemical glass) and E-glass (electrical glass). C-glass has a higher silica content and superior resistance to acidic and alkaline chemical environments, making it the preferred choice for anti-corrosion coating applications. E-glass offers good electrical insulation properties and is used where dielectric performance is important.

The functional performance of Glass Flakes in coatings and composites is governed by their high aspect ratio and the ability of the platelets to align parallel to the substrate surface during application. When incorporated into an anti-corrosion coating at loadings of 10 to 30% by weight, the aligned glass flakes create a tortuous diffusion path that significantly increases the effective path length that water, oxygen, and corrosive ions must travel to reach the substrate. This barrier effect reduces the rate of moisture vapour transmission and chloride ion diffusion through the coating, extending the service life of the protective system.

Glass Flakes are available in grades differentiated by flake diameter, glass type, and surface treatment. Silane-treated grades are available for improved adhesion to polymer matrices in composite applications. ROCC Global sources Glass Flakes from specialist producers in Asia Pacific and Europe.

Glass Flakes are used primarily as a functional reinforcement and barrier filler in heavy-duty anti-corrosion coatings for marine, offshore, and industrial infrastructure. In epoxy, vinyl ester, and polyester anti-corrosion coatings applied to steel structures including ship hulls, offshore platforms, storage tanks, pipelines, and bridges, Glass Flakes provide a tortuous path barrier that significantly reduces the rate of moisture and chloride ion diffusion through the coating, extending the time to corrosion initiation and the overall service life of the protective system. High-build glass flake coatings applied at dry film thicknesses of 500 to 2000 µm are widely specified for immersion service and splash zone applications where conventional thin-film coatings would be rapidly degraded. In glass fibre reinforced plastics and vinyl ester composites used for chemical storage tanks, pipes, and process equipment, Glass Flakes improve the chemical resistance and barrier performance of the laminate. In thermoplastic compounds, Glass Flakes improve stiffness, dimensional stability, and surface quality in injection-moulded components, providing reinforcement with lower warpage than glass fibres due to their isotropic in-plane orientation.