|SURFACE TREATMENT TECHNOLOGIES|
Contrary to what is beleived, passivation in phosphate coating lines is not for corrosion protection with itself. Passivation is effective when made prior to paintings. It improves adhesion of paint particles and prepares the surface for following applications to have enhenced corrosion protection.
Passivation treatment eliminates unwanted ionic elements which is coming with water rinsing or after zinc/iron phosphate coatings. These type of water hardening ions have poteintial of producing salts under paint film which can cause blistering or tear of paintings. For all these reasons, use of passivation chemicals improves corrosion protection of painted, especially, powder coated metal parts.
Chromium passivation treatment is used under conditons of % 0,2 - 0,3 chemical concentration and at ambient temperatures. The treatment solution includes hexavalent chromium ions, hence it must be converted to trivalent chromium while discharging.
PHORYL PAS 15 - Chromium Passivation
It is an effective passivation chemical available for both spray and immesion applications after zinc phosphate or iron phosphate coatings. Treating time varies in the range of 45 - 60 seconds at ambient temperature. Use concentration is around % 0,3. Hexavalent chromium must be converted to trivalent form while discharging.
PHORYL PAS 17 - Chrome-free Passivation
It is a zirconium based chrome free passivation product used after iron phosphate or zinc phosphate coatings. Immersion and spray applications are available. Passivation treatment can be run at ambient temperature with a time duration of 45 - 60 seconds. Product concentration is around %0,3. pH of the solution must be kept in the range of 4 - 6.
PHORYL PAS 18 - Neutralisation
PHORYL PAS 18 is a immersion application mid alkaline neutralization product used after zinc phosphate coating in wire and tube drawing operations. Zinc phosphated metal wire or tube goes into neutralization solution and after that it is generally goes into reactive soap solution. In zinc phosphate coating lines without reactive soap, neutralisation provides corrosion protection itself and deposites a carrier film on phospahte coating which has good holding ability of dry soaps. The treatment is made under conditions of %0,4 - 1,5 chemical concentration, 60 - 70 °C degree temperature and 1 -28 minutes of treating time.
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