Converting to potted Koch KPAK ultrafiltration (UF) membrane in the automotive electrodeposition paint process from the drop-in style process can lead to greater flux stability over time and lower system downtime, says filtration and water purification solutions company Sagisa sales engineer Kamren Munsamy.

The function of the Koch KPAK UF membrane in the automotive sector is to create higher, stable UF permeates.

Munsamy explains that the Koch KPAK UF membrane takes feed of the excess paint from the E-coat bath into two streams. Stream 1 is the concentrate, containing paint solids and pigments, which is returned directly to the E-coat bath. Stream 2 is the UF permeate, which contains UF water and paint solvents.

He adds that, in Stream 2, the UF permeate is used to rinse the excess paint off vehicles in multiple steps to ensure that the paint is returned to the E-coat bath and, therefore, is not wasted.

“If the UF permeate flow is not high enough, the automaker can end up with improper rinsing and wasted paint, which may lead to defects on the body of a vehicle,” he points out.

Recently, Sagisa has supplied the Koch KPAK UF membrane to vehicles distributor Toyota South Africa Motors, in Durban; automaker Ford Motors, in Silverton; and metal pressings producer Malben Engineering, in Nigel.

Meanwhile, Munsamy says the company will work on an oil emulsion concentration project – the UF degreaser system – using tubular UF membrane to achieve oil removal in the automotive degrease steps during a paint pretreatment process.

“The UF degreaser system is installed to condition and maintain the high quality of the degrease tanks that are used for the initial degreasing and cleaning of vehicle bodies and parts before painting.”

He explains that current technology causes difficulty when removing the oil from degrease tanks; however, because these tanks are discarded or cleaned only yearly, they do deteriorate over time and, subsequently, cause vehicle parts to carry defects because of ineffective parts washing and oil carry-over in downstream processes.

Further, excessive maintenance could be required to assess whether oil must be removed. The tank content can cause many effluent upsets.

Munsamy states that the UF degreaser system will successfully concentrate oil for settling and removal, for reuse or discard, and maintain high-quality degrease tanks. Subsequently, better-quality water in tanks downstream can also be maintained, further reducing dump rates and conserving water.