47033

E COAT Paint Ultra Filtration System Fouling [India] 

November 15, 2007

My name is Anil Shah, we are suppliers of Ultra Filtration Systems required for the E COAT Process in Automobile Industry. We face a typical problem with UF systems. They run well for the first year or two with excellent permeate flux stability, and also recovery of flux on system cleaning. However, subsequently permeate flux stability and recovery is a problem even with newly installed membranes.

I assume that this is possibly because the paint bath and its chemistry are good for the first year or so due to low production volumes, however, subsequently the chemistry is getting disturbed and is adverse to UF system operation.

The customer usually refers to the system supplier - however, we have limited understanding of paint chemistry. I will appreciate if some generic guidelines can be provided for testing of paint chemistry parameters which affect UF system performance.

ANIL Y. SHAH
Supplier - E Coat UF Systems - Mumbai, Maharashtra, INDIA

The answer, my friend is swirling in the tank!

If the quality of coating is perfect, the chemistry of the Ecoat tank is in perfect health. If the customer has severe coating problems, your UF membrane could be affected. Just walk around the shop floor and see the final coating quality. You will know whether it is safe to put in the new membrane or not.

UF membranes are certainly affected by ionic contamination. But in that case the coating is already being affected and there can also be generation of sludge in the tank.

Check if regular tests are being carried out on the tank.

Gurvin Singh Coatec India - Mohali, Punjab, India

We are car assemblers in Malaysia. Recently we switch to lead free E-coat paint for our Cathodic ED system. Since then we experience high fluctuation in the ED dip tank paint level. Some times abnormally low level or very high level, which force to stop production.

Seek your kind advice to solve this problem.

Thank you in advance.

JEYA ANAND
- Kuala Lumpur, Malaysia