zinc flake coatings

Zinc Flake Coatings

The Anochrome Group is the UK’s largest independent specialist surface coatings service provider, offering expert zinc flake coating services to companies around the world. As zinc flake coatings are one of the most important types of corrosion protection systems available, Anochrome ensures they are at the cutting edge of the latest technologies.

The Anochrome Group offers zinc flake coatings at Wolverhampton Electro Plating Ltd, Anochrome Ltd & Anochrome Technologies Ltd in bulk.

These coatings are often used with a top coat that can improve corrosion resistance, give barrier protection, or act as a torque control or modifier, such as the Magni® System, Delta MKS® from Dörken®, and Geomet® from NOF® Metal Coatings (formerly Dacral®). Please click on the following for more information on these top coats:

Dorken MKS-System GmbH & Co. KG
Magni Coating
Geomet Coating
Dacromet Coating

Today’s zinc flake finishes are the result of many years of work and development around the world. The concept of taking zinc and adding this to an inorganic binder to create a material that is both functional in its performance and simple to apply has many advantages over more traditional plating systems – namely that component size, current density problems and embrittlement issues can be avoided.

Systems using zinc dust commonly around 3um in size are the most cost effective type of zinc enriched paints. Sometimes the zinc is supplemented or even replaced by aluminium to modify certain performance characteristics. There are a number of manufacturers of these systems including Trimite® and Schramm® who offer a comprehensive range of finishes and performances, most of which can be supplied by the Anochrome Group.

To achieve a good corrosion protection any zinc particle within the binder matrix must be in contact with its neighbouring particle. The contact area with zinc dust is not large, however if the zinc particles were platelets or flakes of zinc around 15µm in size, then the increased surface area allows the contact interface between particles to be improved. The result is a greatly enhanced performance in terms of corrosion resistance. This improvement, in turn, allows for an increase in binder to pigment ratio, resulting in a more durable zinc flake coating.

The Anochrome Group has a number of dip-spin coating lines, as well as automated spray coating lines and a manual facility for large or awkward items. The Groups laboratory and salt spray (ASTM B117) testing facilities offer a complete package to meet the ever increasing requirements of industrial and automotive corrosion protection specifications.

What are the key performance advantages of zinc flake coatings?

• Excellent resistance to atmospheric corrosion.
• Limited “white” rust (zinc corrosion products) or other corrosion products in service.
• Complex shapes and sizes, recesses and holes are coated with suitable equipment.
• Neutral salt spray corrosion resistance exceeds that of many other common surface finishes e.g. electro and mechanically plated zinc.
• Good resistance to “mild” chemicals and solvents including petrol and brake fluids but  not resistant to strong acids.
• No hydrogen embrittlement. It is a non-electrolytic process – most surface preparation is carried out by mechanical blasting.
• Has some degree of electrical conductivity.
• Galvanic protection by the zinc-rich coating ensures satisfactory performance at bimetallic contacts with steel, aluminium, zinc and cadmium in most situations.

What types of part are usually zinc flake coated?

• Threaded fasteners, particularly strength grades 10.9 and 12.9.
• Bolt, nuts, pressings, springs, clips, sub frames for automotive, wind energy, domestic appliances and building components.

We understand that a tailored approach to zinc flake coating is essential to your business. You can email us via the Contact page to discuss your individual requirements with an expert. We are also happy to provide you with further information on the zinc flake process by email, or alternatively you can call us on 01902 397333.