Ultrafiltration is a pressure-driven membrane process capable of separating soluble components on the basis of molecular size and shape. Under an applied pressure difference across an ultrafiltration membrane, solvent and small solute species pass through the membrane and are collected (permeate) while larger solute species are retained by the membrane and recovered as a concentrated Retentate.
In Electrocoat paint systems, the ultrafiltration permeate contains water and paint solubilizers.
The Permeate is used in the paint line rinse section. This recycling method provides a closed loop rinse system for recovering paint solids (drag-out). The Permeate can also be diverted to drain to reduce conductivity of the paint.
The filtrate capacity refers to the membrane cartridge surface area at a certain paint recirculation capacity and is known as the “specific filtrate capacity”. It depends on the type of paint used and must be determined from case to case by way of measurement.
Flushing Parts after leaving the UF Rinsing tank
