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Kemphos - 325
(Light Zinc Calcium
Phosphating Chemical)
Product
description
Kemphos-325 is widely recommended for automobile, refrigerators,
furniture, air conditioners, electrical industries where single coat
of gloss paint required. Kemphos-325 is an accelerated warm Zinc
Phosphating process, which is specially formulated to produce fine
and smooth coating on steel and zinc surfaces. Smooth coating serves as
a good base for paint and reduces consumption of paint and retains
paint gloss. Fine micro crystals of phosphating coating increase paint
life and presents spread of rust even after the damage of paint film.
Thus, it prevents blistering of the paint film
Product
Specifications
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a.
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Colour
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Light Pale Yellow Liquid
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b.
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Chemical Composition
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Blend of Phosphates, Nitrates, Zinc, Activators,
etc.
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c.
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Odour
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Slightly Pungent
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d.
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Foaming Tendency
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Nil
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e.
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Reliability
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Good
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f.
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Handling
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Avoid Skin Contact
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g.
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Solubility
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Good
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h.
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pH
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Acidic Range
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I.
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Toxicity
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Nil
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j.
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Flash Point
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Nil
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k.
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Pollution Hazard
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Moderate
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Product Operating Data
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Concentration
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3 to 5 litres for 100 litres of bath
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Total Acidity
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18 22 at 3% strength 35 at 5% strength
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Temperature
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60 70 °C
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Accelerator
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20 gms/100 litres of
bath. If operated below 70oC
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Accelerator Pointage
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2 - 6ml
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Acid Ratio
Acid ratio of the phosphating bath should be maintained as per the
recommendation I.e. between 5 7. Acid ratio is determined as
follow:
Acid Ratio: Total Acidity (bath pointage)
Free Acidity
When Kemphos-325 bath operated accelerator (Kemphos-325) at a higher
temperature , aging of the bath should be carried out with degreased
steel wool.
Product Operating Procedure
The complete process for the application of Kemphos-325 solution by
immersion normally consists of the following steps
Degreasing
Running water rinse
Derusting/Descaling
Running water rinse
Surface Activation
Phosphating
Running water rinse
Passivation
Carryout the Following Operations in The Order Given
Determination the working volume of the tank fill the tank with 2/3
of water and heat it about 50°C. Add Kemphos-325 at 3 5 ltr.
Bath and stir it well. Raise the temperature to its operating
temperature 60 70°C and fill water to its operating level.
Add 20 gms. of accelerator dissolving in water per 100 ltr. Bath. Now
check the pointage of the bath solution and accelerator by Potassium
starch Iodide paper. Before starting production the bath should
matured and the colour of the solution will be milky white.
Product Application Equipment
Kemphos-325 tank should be fabricated with 3 to 4 mm thick M.S.
Plates with continuous current hating system.
Testing and Control Procedure:
Total
Acidity
Pipette out 10 ml. Of the solution
in a conical flask. Ass few drops of indicator Phenolphthalein and
shake it well. Titrate against N/10 NaOH until permanent pink colour
persists. The number of ML of N/10 NaOH added is the pointage of the
bath. Adjust the pointage by adding emphos-325 to the bath for each
one pointage less add 125 ml. Of Kemphos-325 per 100 litres of bath.
Accelerator
(Kemphos-002) test by starch Iodide Paper
Check the bath temperature. Dip a
piece of starch Iodide paper in the bath. After some seconds colour
will Indicator the concentration of bath.
Kemphos -002
(Accelerator)
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Starch Iodide Paper
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No Accelerator
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Remain White
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Insufficient
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Pale Mauve
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Optimum
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Blue to Dark Blue
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Excess
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Black
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It is essential to have correct
amounts of accelerator,excess addition of accelerator in the bath
causes sludge formation and wastage of Kemphos-325.
Titration
Test for (Accelerator 002) Concentration
Pipette
out 50 ml. Bath solution into flask. Add 5 ml of concentrated H2SO4
and mix it well. Titrate against O.I.N. KmnO4 solution to a pink
colour which persist for few seconds.
Note, the number of ml. of 0.1N KmnO4
added in the (Accelerator-002) concentration. Normal limit for
accelerator-002) titration is 2-6 ml. Lower limit is preferable.
Approximately 30 ml. Of 25%
Accelerator-002 solution in water should be added to increase the
(accelerator-002) pointage by 1 ml.
Ferrous
Iron Concentration
Pipette out 10 ml. Of bath solution
in 150 ml. Conical flask. Add 2 ml or 50% H2SO4 and titrate with N/10
KmnO4 (3.16 gms/ltr.) solution to pink end point persisting for 15
seconds. Multiply by the titration reading with 0.056, we get
percentage of Ions in the bath.
Chemical Replenishment
Since there is continuous sludge generation in phosphating bath due
to phosphating of ferrous metal surface, the bath should desludged
periodically and chemical concentration should be replenished by
adding chemical to achieve specified bath pointage.
Safety Measures
Kemphos-325 is an acidic liquid
material, and while handling proper care should be taken. Protect
eye, skin by means of goggles, gloves etc. It comes in contact with
skin and eyes wash thoroughly with flush off water and get medical
advice.
General
Information
Corrosion Resistance:
Good
Paint Adhesion: Good
Gloss Retention: Good.
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