ZP-KOAT-50
SCOPE: -
ZP-KOAT -50 is an advance formulation for the process of Zinc Phospheting of the sheet metal Components. ZP-KOAT-50 is immersion type chemical. ZP-KOAT works efficiently at lower temp. And Gives crystalline zinc phosphate coating. ZP-KOAT-50 enhances corrosion resistance and paint film Adhesion to metal surface.
PROCESS: -
The articles to be processed in ZP-KOAT-50 should be free from impurities like grease, oil, and dust in order to remove oil grease form metal surface. The article to be treated with METACLEN-30 degreaser.
Prior to phosphating, the corrosion resistance of phosphated article is increased by treatment with Passivating solution.
APPLICATION: - (MAKE –UP): -
Fill the tank with water up to 3/4th of tank. ADD 40 Litters of ZP-KOAT -50 for every 1000.litters of Water. And make –up the level up to operating level with water. Heat the bath to the operating Temperature. Add 350 –ml. of Toner -6/12 for every 1000 litters of water.
BATH PARAMETERS: -
Temperature RT to 60 c
Total acidity 30+/-1
Free acidity 1.07=0.1
Toner concentration 10 to 15
CONTROL AND REPLENISHMENT
1) Total Acid Point age
Total acid pointage is the number of ml s. Acid point age pipette out 10ml of bath solution in a clean 250ml conical flask. Add 2 to 3 drops of phenolphthalein indicator and titrate with 0.1N sodium hydroxide Solution till pink colour appears. To increase total acid point age by 1 Points add 2 litters of ZP-KOAT -50
For every 1000 litters of water.
2) Free Acid Point age
Pipette out 10 mls of phosphating bath solution in a 250 ML conical flask. Add 2 to 3 drops of Bromophenol blue indicator and titrate with 01.N sodium hydroxide Solution will yellow colour turns to Blue violet.
3) Toner concentration
To check to Toner concentration in phosphate bath starch iodide paper is used. Dip starch iodide paper into ZP-KOAT – 50 Solution. The paper should turn blue. If paper Remains colourless, it indicates low concentration of Toner 6/12. In the increment of 100 MLS for every 1000 litters. Of ZP-KOAT – 50. until change of colour To blue occurs when starch iodide paper is dipped.