Henkel: Improved rinse-free adhesion promoter for metal pretreatment

Rising energy and water costs, stricter environmental regulations, and the shift to chrome-free processes are increasing the pressure on metalworking companies to make their pretreatment processes more cost-effective. With APNR 2.0 (Adhesion Promoter No Rinse), Henkel is introducing the next stage in the development of its adhesion promoter technology. According to internal evaluations, APNR 2.0 can reduce process water consumption by up to 50 percent and compressed air consumption by up to 20 percent compared to the previous generation. Actual savings depend on line design and operating conditions. APNR replaces the conventional passivation bath with a precisely metered spray application of the adhesion promoter at the end of the line. The solution is freshly prepared inline and applied as a thin film to the still-wet surface. A subsequent rinsing step is not required.

Less Water in Metal Pretreatment

Since its market launch in 2015, more than 100 APNR systems have been installed worldwide. The technology enables more compact line layouts and reduces water and chemical consumption while maintaining high corrosion protection and good paint adhesion. APNR can be retrofitted without major modifications, particularly in existing plants with limited space. For architectural aluminum, the technology also enables the transition from systems using hexavalent chromium to chromium-free alternatives. With APNR 2.0, Henkel is now introducing the new EcoFlex control unit. It combines an updated control architecture with a newly designed pump system, monitors conductivity, pressure, and tank levels, and can be integrated into digital systems. The goals are to further reduce media consumption, minimize downtime, and simplify operation.