Modern paint and coating systems require quality Paint Booths to ensure a high quality coating finish. Manufacturers rely on the technology of spray painting and paint booths to satisfy the needs of present-day consumers for surface finish quality. However, paint booth systems need significant attention to maintenance to ensure booth performance and final paint quality. A decline in system performance will result in an increase maintenance costs and negative impact to the performance of the paint booths.
The effects of sludge deposition on booth equipment
The operations of the paint booth are compromised by the presence of sludge in the equipment and the booth itself. Buildup of sludge on flood sheets will affect water distribution and can lead to open gaps where overspray can make its way into scrubbing chamber and up the stacks. Booth balance will be severely affected and can potentially impact on the quality of coating finish. A buildup of sludge in the piping system will restrict water flow. Paint sludge when it reaches the stacks is a signal that the balance of the paint booth has been compromised and sludge will eventually exit the stacks to negatively impact on the nearby environment. The ultimate result will be the need to shutdown the system, clean out the sludge and dispose of it according to local environmental regulations.
The importance of water chemistry in paint booths
Many paint booths are operated using the water-based systems to remove overspray. To ensure that the system will run efficiently, there must be a fully functional and properly designed sludge handling equipment as well as an application of a booth chemical program that matches with the equipment. If certain key parameters are overlooked even the best chemical program is bound to fail. The key parameters that have to be given attention include pH, alkalinity, total dissolved solids, conductivity, turbidity and suspended solids.
pH is the measure of acidity of an aqueous solution and in order to maintain pH within a prescribed range, there must be paintdetackification and sludge conditioning polymers. If pH is outside of the optimum range it can increase the amount of suspended solids or result into loss of sludge dryness and increased foaming. Total alkalinity is the amount of acid necessary to bring the pH of a sample to 4.2. In many cases pH and alkalinity are related in maintaining an alkalinity level otherwise the same issues will be present if there is an out of range level of alkalinity.
Not all paint booths are the same and at some point, high conductivity in the paint booth water can have the same impact as total dissolved solids in increasing suspended solids, paint deposition, watery sludge and the potential for foaming. Conductivity is also affected by temperature; the warmer the temperature the higher will be conductivity. High conductivity can increase the potential for corrosion in the metal surfaces of the system.
High levels of turbidity caused by solids suspended in water can lead to less paint sludge being removed during the process. High turbidity will also trigger formation of high levels of foam.