ZINC PHOSPHATING (DIPPING APPLICATION)

Zinc phosphate (Zn₃(PO₄)₂) is an inorganic chemical compound used as a corrosion resistant coating on metal surfaces.

Phosphate salts is applied via spraying or immersion and chemically reacts with the surface of the part being coated to form a layer of insoluble, crystalline phosphates. Normal operation pH : 2.6 - 3.0

The operation should be controlled, to make best result :

- Temperature (if use Hot Temperature)

- Time

- pH

- Product concentration

- Free and Total Acid

  --Total acid is measure of total bath concentration/ Zn Content
  --Free Acid is maintain Zn solubility

The other chemicals should be add  in Zinc Phosphating are :
- Accelerator  (Dia Toner 20)
- Neutralizer (Dia Starter 40 - maintain pH, Free acid)

Advantage :

- Coating thickness 2.000 - 10.000 nm (usually 1.5 -  2.5 g/m2)

- High corrosion protection

Quality requirements on phosphate coating prior to painting :

- Uniform, small crystal

II. Zinc Phosphate, 2 kation (dipping application) :

Our Product : Diafos 2000-1 Alim, packaging : 30 Kg/can

DIAFOS 2000-1 chemicals are conversion coating agents formulated for treating mixed production of zinc-coated steel (either hot-dip or electro-galvanized) and steel.  Limited quantities of aluminum can be treated.  Cadmium must never be run through the solution because it will poison the bath.  Immersion application may be used.

The DIAFOS 2000-1 treatment converts the metal surface to a non-metallic, fine-crystal, zinc phosphate coating which inhibits corrosion and increase the adhesion and durability of paint finishes.  This substantial increase in the paint life results from the fact that the coating providers:

A.         A clean, grease-free surface

B.         A corrosion-inhibiting base for paint

C.         A non-conducting bond between the base metal and the paint

D.        A chemically inert surface which prevents reaction between the metal surface and the paint ingredients

Optimum process sequence of phosphating in Customer, Dipping application :

a. Degreasing

    Product : Diaclean H-280

    Concentration : 2 - 5%

    Temperature : 40 - 60°C
    Contact Time : 2 - 15 minutes (depending on the oil)

  Proses sederhana saat trial

 b. Rinsing, prevent contamination

    Product : City water

    Temperature : Room Temperature (RT), ambien

    Contact Time : 1 - 2 minutes

     (Proses sederhana saat trial)

 c. Activation

    Product : Dialene 80

    Concentration : 0.1 - 0.2%

    Temperature : Room Temperature (RT), ambien

    Contact Time : 1 - 2minutes

      (Proses sederhana saat trial)

d. Phosphating

    Product : Diafos 2000-1Alim 

    Concentration : 6.5 - 7%

    Temperature : 45 - 50°C

    Contact Time : 15 - 30 minutes  (depending on the thickness)

    

(Proses sederhana saat trial)

 e. Rinsing, (prevent contamination)

    Product : City water

    Temperature : Room Temperature (RT), ambien

    Contact Time : 1 - 2 minutes

     (Proses sederhana saat trial)

f. DI Water Rinsing, (prevent contamination)

    Product : Demineralize water (DI Water)

    Temperature :Room Temperature (RT), ambien

    Contact Time : 1 - 2 minute
    

(Proses sederhana saat trial)

Degreasing  -- Rinsing --  Surface Conditioning -- Phosphating -- Rinsing -- DI Water Rinsing -- drying

Result of coating with phosphating:

   

Crystal view with SEM (Scanning Electron Microscopy), aplication via immersion (Dipping), material steel :

Magnification 1000x, appearance : round shape crystal, small size, uniform particles 

For more details, please contact us :

PT. Aalen Chemicals Indonesia

Jl. Pulobuaran III Blok G3,

Kawasan JIEP Pulogadung

Tlp : 021-46830522
Website : www.aalen.co.id 
Email : aalen.chemicals@gmail.com, aalen@cbn.net.id