Geomet zinc flake technology opens new horizons for corrosion protection

Large R&D resources in NOF Metal Coatings Europe, winner of European Responsible Care Award 2010, have been allocated in the recent years to the development of the range of Geomet applications. These developments open new possibilities of industrial applications in the field of protection against corrosion, the company said. Examples are high performing black coatings and coatings lasting the required life on chassis components. At the same time, NOF said its R&D team succeeded in developing Geomet chemicals that allow the VOC content of these water-based products to be reduced substantially. 

Black corrosion protective coatings for threaded parts and other metal components are requested for design reasons by the automotive industry as well as in other industrial fields. NOF Metal Coatings Group, a specialist in thin corrosion protective coating materials, offers two families of black coatings: Geoblack ML and Geoblack 500M obtained by addition to the Geomet basecoat Plus Black topcoat.

The Geoblack KT family is a new development with basecoat Geomet and topcoat Geokote Black. This topcoat ensures a high resistance against all chemicals including strong acids and solvents.

In order to obtain a life lasting zinc-based coating on chassis components in the automotive industry, it is necessary to apply a sufficient thickness of coating material, according to the company. Depending on the application, a range of 15 µm to 30 µm will give the appropriate protection. As the usual thickness of Geomet for bulk parts is six to ten µm, ways for increasing the thickness had to be studied, the company said.

A specific product, Geomet 900, has been developed, which enables the application of 15 µm to 30 µm in one or two coats. The product development has been completed together with the application process development. After alkaline degreasing and without phosphating, the components are dipped in the Geomet tank and drawn out at a controlled speed. As the product is non-drip and non-saggging, the drying and curing cycle can start immediately.

Practical trials over two-years and with components of various types and shapes have proved the potential of this development, the company said. Fuel filler tubes for instance can be coated with one coat of Geomet 900 by this process while a black top-coat can be sprayed on the outside part for the color requirement and for additional protection.