Product Categories / Metal Treatment / Steel Treatment / Zinc Phosphating

Duraphos 642

Product description

  • Duraphos 642 is nitrite accelerated dicationic zinc Phosphating product. It produces uniform crystalline zinc phosphate coating on Steel, Iron, and G.I substrate.

Feature:

  • Duraphos.642 is especially suitable to give paint adhesion process.
  • Coating weight per unit area is about 2-4 gm/ m².
  • Duraphos.642 is made for spray application and can be used in dip application.
  • Duraphos 642 contains an additive especially formulated to reduce the sludge in the zinc phosphating tank.
  • Duraphos 642 contains more nickel to improve durable pre-treated surface.

Applications

Duraphos 642 is a specially formulated product most suitable for steel, galvanized and micro galvanized steel.

Physical & Chemical Properties:

Appearance : Liquid.
Color : Green.
PH (1%) at   25°C : 2.4 ± 0.2
Sp. gr. at   25°C : 1.4 ± 0.05
Free acid point (1%) : 1.7 ± 0.2
Total acid point (1%) : 8 ± 0.3

Equipment:

The main process tank can be fabricated from Stainless Steel or acid resistance material tank is recommended for durability. Pumps & nozzles must be of S.S. Grade 316 or PVC.

Operating Parameters:

Concentration (v/v %) : 2.0 to 4.0
Temperature (°C) : 50 to 60
Time (min) : 1 .0 to 3.0
Nozzle pressure : 1 to 1.5 bars
Free acid point : 0.8 to 1.5
Total acid point : 14 to 28
Acceleration Point : 3 to 6 (for steel), 2 to 4 (for GI steel)

Initial Preparation :

  • Add 20 to 40 lit of Duraphos.642 per 1000 lit of operating volume.
  • Add Duradd 14 periodically and slowly while thoroughly mixing, till free acid point adjusted.
  • Free acid point adjusted for different line applications and different type of steel, optimum work Pointage is 0.8 to 1.5.
  • Add 500 to 1500 ml Duradd 13 per 1000 lit of operating volume (To be added just before starting the line).

Process Sequences:

  • Cleaning & Degreasing with Duraclean products.
  • Water Rinse.
  • Water Rinse.
  • Refining and activation with Duradd 5
  • Zinc Phosphating with Duraphos 642
  • Water Rinse.
  • Passivation with Durapass products
  • Drying

Precautions

  • Carry over should be avoided as much as possible
  • Oil should be skimmed regularly from the degreasing tank.
  • Total acid point, free acid point, and accelerator point should be checked at least twice in a shift and especially before replenishment.
  • Rinsing water should be changed frequently.
  • Temperature of Zinc Phosphating tank should be maintained all the time.
DOWNLOAD