Evonik Industries and SI Coatings have jointly developed a water-based primer for the pretreatment of steel prior to coating in the fluidized-bed process with VESTOSINT polyamide 12 powder.

Polyamide coatings on metal serve to protect against corrosion. Until now, large-area steel parts, especially concave surfaces, were pretreated with solvent-containing primers when exceptional adhesion was required, for example, in contact with water.

“Evonik has firmly anchored the idea of environmental compatibility in its corporate strategy. Therefore, for the processing of VESTOSINT we were looking for a partner with whom we could develop a water-based primer that is precisely matched to our polyamide powder. We found this partner in SI Coatings,” says Dr. Dominic Störkle, head of the Additive Manufacturing & Material Solutions product line at Evonik.

The result, the company says, is a reliable water-based primer that does not require any special work protection technology such as fume hoods. The product is label-free according to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS). The residual solvent content, reported as volatile organic compounds (VOCs), is less than two percent.

“Since we are a globally active company, we can offer the jointly developed primer to Evonik customers worldwide and also in small quantities,” says Managing Director Andreas Kunz of SI Coatings.

The new primer Si Coatings 100011-00L with water hazard class WGK1 has a shelf life of six months when stored frost-free. It can be applied by brushing, spraying, dipping or doctoring and baked at about 300 C during heating for the fluidized bed process with VESTOSINT. One possible application is cardan shafts, which are coated on both the outside and the inside.

Evonik markets the plastic polyamide 12 as a powder under the name VESTOSINT, for example, for coating dishwasher baskets, metals in household goods, the automotive industry or medical technology.

www.evonik.com