Alfipas 7816 - One product for three applications
The ENVIROX SG process is a chromium-free corrosion protection process that can be used for the pretreatment of steel and aluminium surfaces as well as for hot-dip galvanised substrates prior to powder coating. Alfipas 7816 is used here, which covers the treated metal surfaces with a firmly adhering, three-dimensional network (gel protective film) and thus offers excellent corrosion protection for final coating.
Advantages:
Multifunctional application on Fe, Al and Zn
Visible yellowish layer on Fe, colourless on Al and Zn
Cost-effective integration into existing systems; suitable for evaporator technology
Fully-fledged, sludge-free substitute for iron phosphating in steel pretreatment
Approved for Al pretreatment according to Qualicoat (No. A-70) and GSB International (No. 303c)
Analytical layer determination by quick test and quantitative, photometric measurement method
Temperature-resistant layer up to at least 170 °C (annealing of Zn is possible)
Simple waste water treatment by precipitation using lime milk
Application and process sequence
Example of a process sequence for Al, Fe and Zn pretreatment with Alfipas 7816 in a plant (see right diagram).
Alfipas 7816 can be used both in spraying systems and in dipping processes. Rinse with deionised water before using Alfipas 7816.
The process sequence and the type of pretreatment depend on the individual surfaces and the prevailing plant options. When pretreating aluminium and hot-dip galvanised surfaces we recommend an alkaline (etching and) degreasing followed by acid etching. In the case of mixed operations (Al +Zn), the zinc content in the acid etching bath should be carefully monitored.
Steel substrates are also cleaned in the alkaline process bath (1st zone) before being rinsed and treated with Alfipas 7816.
After the ENVIROX SG process, the fabric is again briefly sprayed with deionised water before being transferred to the dryer.
Corrosion protection ratings which can be obtained under ideal conditions
Material | Test criteria | Result |
|---|---|---|
Steel panel | NSS, 1000 h DIN EN ISO 9227 | Infiltration 1 mm |
Hot-dip galvanised panel | NSS, 500 h DIN EN ISO 9227 | Infiltration 2 - 3 mm |
Aluminium panel | AASS, 1000 h DIN EN ISO 9227 | Meets the specifications of the Qualicoat and GSB International (quality associations) |
DI = fully demineralised water
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