Layer structure variants

Areas of application for zinc flake systems

The most widespread processing with zinc flake systems is the processing of bulk goods in the dip-spinning process, e.g. bolts, nuts, clamps, clips, springs, rivets, rivet nuts, smaller stamped/bent parts, etc. The application of zinc flake surfaces for rack goods is growing continuously. Components with complex geometries are also coated on a rack by dip-spinning or spraying processes. The great advantage of dip-spinning on a rack is that components with cavities, undercuts or double surfaces can be completely coated reliably with a very good surface quality.
Zinc flake systems
Various fastening elements with zinc flake coating

Features of zinc flake coatings

The coating of components with special requirements, partial coating or the production of different layer thicknesses on one component are all made possible by state-of-the-art, robot-assisted painting systems. Components, for example, are precisely coated rotating on robot-guided spray heads. Example: brake discs, complete wheel bearings or electrical motor components from the e-mobility sector. The most accurate possible adherence to the layer thicknesses in the respective required areas can be reliably reproduced with minimal fluctuations. In this way, elaborate masking can also be avoided in some cases.

Zinc flake systems are particularly attractive in composite and mixed construction and are an indispensable surface for lightweight construction strategies. On the one hand, a wide variety of material combinations present a major challenge in preventing contact corrosion. On the other hand, there are new steel alloys which make weight-reducing component design, e.g. in the chassis area, only possible if reliable active corrosion protection is applied. In comparison, partial damage due to assembly or during operation due to stone impact etc. must be avoided at all costs in the case of passive coatings, since corrosion occurs immediately and the component is massively damaged.

In summary, the characteristics of zinc flake coatings are as follows:

  • Thin layers, depending on requirements 7 – 25 µm
  • No hydrogen embrittlement in the process
  • Lowest hydrogen hazard potential during operation/under corrosive loading
  • Free of heavy metals
  • Best corrosion protection for lightweight construction strategies
  • Can be used on high-strength steels
  • Very good remote protection effect even with partial damage
  • Process-safe coating of cavities and double surfaces

Author: Peter Messing, Global Key Account Manager Zinc Flake Systems Aalberts Surface Technologies GmbH, Kerpen, Germany.

Aalberts Surface Technologies GmbH is a license partner of market-leading zinc flake suppliers and is represented with state-of-the-art application technology at locations worldwide.