Coatings and Paints

The quality of the final finish of any coated or painted surface is determined by the level of particulate contamination found in the coating or the paint applied. If contamination is not prevented entering or removed during manufacture, storage, or transportation the final surface finish will be compromised, and the visual appearance diminished.

Uneven coating, cratering, and blemishes in the surface are common final finish issues, but contamination can also lead to blocking of paint spray nozzles, which causes downtime, delays to products and additional servicing costs for the paint or coating shop.

Both bag and depth filters can be used to prevent these problems without impacting the paint itself, by removing dispersed pigments and any particulate contamination. They will remove any coagulated pigments, even though these are gel like in nature and can extrude which makes them difficult to filter, but due to the torturous nature of the filtration path and the depth of the filtration media in bags for depth filters these are removed.

To guarantee the cleanliness of the entire process filtration is used as follows:

• Incoming raw materials (solvents, water)
• After paint mixing
• Before paint spraying
• Return loop to mixing tank

Dependent on paint type (solvent or water-based) and its quality, the material of construction of depth or bag filter will vary. Polypropylene is chosen for water-based and nylon for solvent-based paints, both being available in a wide range of micron ratings to suit the different chemistries possible.