plating, anodizing, & finishing Q&As since 1989
CED low bath turnover
July 15, 2010
%NV (15-16%) AND % ash (20-21%) are dropping due to low bath turn-over, how can we increase this in terms of equipment usage....does shutting-off of UF system affect it?Warren Ty
product engineer - Cebu, Phillipines
July 29, 2010
NVM will only drop when paint is consumed by the coating process or paint settles down due to improper circulation or draining of the bath from the tank.
If you can identify the reason for the drop in NVM, it will be straight forward to solve it.
I hope that fresh paint addition is being done with production to maintain the NVM! We do not expect the E-coat bath to produce NVM on its own.
Improper circulation will show up as paint deposit at the tank bottom. A dip stick with a metal plate at the bottom can be used after disconnecting the rectifier completely to investigate settling.
Do you have a drain valve? Is the permeate loop complete? Is the permeate rinse water coming back into E-coat in the closed loop? There can be quite a few ways to lose E-coat bath NVM!
Hope this helps.
Mohali, Punjab, India