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"Need uniform ED coat in CED process in the recess areas"
Hello sirs I humbly feel that it's really a great time to interact with you wizards. in our CED process, we are encountering a major paint problem poor E'coat deposition (dipping process) defect in the sill outer panel of the car body because of "rust" in the non-coverage area of coating. this is not occurring in the sill outer panels we use which are provided with wax holes.
I'm really baffled whether the problem is with the process parameter settings or the mechanical alignment or settings .
the process parameters settings we use in our CED process are :
%NVM = 18.7
pH = 5.94
CONDUCTIVITY = 1827 uS
P/B RATIO = 0.16-0.25
BATH TEMPERATURE = 30.7
APPLIED VOLTAGE = INLET POINT = 0 V
OUTLET VOLTAGE = 100 V
MAIN BUS = 235 V
CURRENT = INLET = 0/350 amps
MAIN = 950 amps
when we change the inlet voltage, paint defect "hash marks" start appearing in the car bodies . we are planning to increase the %NVM or the inlet voltage , WILL IT SOLVE THE PROBLEM !
generously give me your valuable suggestions .
ED = electrodeposition ["e-coating", "electropainting"]
CED = cathodic electrodeposition
NVM = non-volatile material
P/B ratio = binder-pigment ratio
C Nanda Kumar graduate engineer - Chennai, India ^
April 12, 2009
TRY TO ADJUST THE CONDUCTIVITY IN RANGE OF 1200 ~1300. P/B RATIO IS IN MUCH HIGHER RANGE IF You HAVE 6TH GENERATION PRODUCT THEN THIS SHOULD BE IN LOWER RANGE AS NEAR BY .13.
DINESH MAURYA - jamshedpur, India ^
July 10, 2010
1. If possible try to increase the number of anodes
2. increase the solvent content of bath.
Ravish Singh - New Delhi, India ^
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