Zinc powder (450x) Zinc paste (450x) Mode of action of Zinc flakes Apart from the cathodic corrosion protection provided by Zinc, Zinc flakes offer the additional advantage of excellent barrier protection. Cathodic corrosion protection is guaranteed by factors including conductive contact between Zinc and the steel surface and between the Zinc particles themselves. Whereas spot contact with relatively high resistance is achieved with Zinc dust particles, Zinc flakes have twodimensional contact which brings about a higher current density and hence a better anti-corrosive effect, though it can also lead to more rapid degradation of unprotected Production flowchart Zinc paste (Wet milling process) Raw material Zinc granules / Lubricant / White spirit Steel ball mill Batch production Milling down of zinc granules using steel balls Screening Separation of various particle sizes Filter press Drying until desired solvent content Phlegmatization (Mixer) Homogenization Final product Final test report / Packing Zinc flakes. To counteract this, fillers in flake form and/or additional anti-corrosive pigments are often incorporated in the formulation. Due to their platelet-like strukture, flakes have a markedly larger surface area than spherical Zinc dust. The correspondingly higher binder uptake allows formulations with a lower pigment volume concentration (PVC), which in turn leads to favourable application and paint properties. Paint properties, application and handling Especially the large surface area/high binder uptake, which means less need of Zinc in the formulation lead to a lot of advantages: · Greater flexibility · Better substrate and intercoat adhesion · Good overcoating properties · Low porosity and permeability · Smooth surface area · Metallic appearance · Lower settling tendency · Sediment easier to stir up · Less Zinc to store / to handle · Higher productiveness · Less Zinc need per m2 –> ecological advantage The use of Zinc flakes offers predominantly technical and ecological advantages without any economic drawbacks.
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