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CLOUDY LIKE APPEARANCE ON CHROME PRINTED CYLINDER

OUR COMPANY HAD ENCOUNTER PROBLEM IN CHROMING WE USED A CURRENT DENSITY OF 80 A/dm2. WHEN WE CHROME PRINTED CYLINDER WITH DIAMETER OF 570 MM THE APPEARANCE WAS CLOUDY WHICH LEADS TO SMEARING DURING PRINTING PROCESS

RICHARD TAN
PLANT MANAGER - QUEZON CITY, PHILIPPINES
February 3, 2009

Cloudy is normally the same as milky and is normally too low an amperage for the temperature. The resultant chrome tends to be soft.

James Watts
- Navarre, Florida
February 5, 2009

DEAR SIR,I SHOULD WANT TO SHARE YOU BASE OF MY EXPERIENCE ABOUT DECORATIVE OR HARD CHROME PLATING,NORMALLY COLOR OF CHROME FINISH IS A BLUE-ISH FINISH BUT IF YOU ENCOUNTERED CLOUDY THE ONE CAUSES OF THIS IS HIGH OF CHROMIC ACID SALT.TRY TO ADJUST THE DENSITY LEVEL BEFORE YOU ADJUST THE SULFURIC ACID LEVEL.DONT USED HEATER IF YOU HAVE BECAUSE HEATER IS FOR HIGH TRIVALENT CHROMIUM. I AM A TECHNICIAN AS MY WORK HERE AND THE FIRST FILIPINO WHO KHOWS ABOUT PLATING IN PLASTIC.

LUDIVECO G PEREZ
- SHARJAH UAE
February 20, 2009

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February 20, 2009

I will politely disagree with the previous post. Texts give massive ranges of chrome concentration that work. The major factor is maintaining about a 100:1 ratio with the sulphate.

Chrome should be analyzed and not by using color or baumé or SG as a given since dissolved iron and other metals causes huge changes from the truth.

If you consult a good book on chrome, you will find a diagram of temperature vs amperage to get bright plate. For my uses, a heater was absolutely needed until the heat generated by the plating process would maintain it. In one place that I worked, we had to use cooling coils about mid day because of the heat generated. Chrome plating is a very inefficient process.

James Watts
- Navarre, Florida

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I generally find that a milky appearance in a chrome plated surface stems for poor rinsing prior to the chrome tank. I also agree with the previous posting the ratio, temp, and the chrome concentration is critical to the plating process.

Do any of the previous steps (rinses or chrome activation) have air agitation running during the plating operation?

Will Kirkendall
- Belding, Michigan, USA
March 10, 2009