Basic production hygiene is essential to ensure that biofilms, incrustations, adhesions or other residues on the walls of the rinsing zones or in the ETL tank do not disrupt the coating process or even lead to production downtime. As modern coating systems can promote bacterial growth, FreiLacke recommends basic cleaning, intermediate cleaning and continuous measures.
System cleaning once a year
According to the paint manufacturer's recommendation, a complete system cleaning should be carried out once a year. This involves pumping the ETL tank into the counter tank and removing sludge, residues and other impurities from the tank. The rinsing zones are drained and incrustations and residues are thoroughly removed using suitable methods such as high-pressure cleaners. Subsequent preservation using suitable biocides is important.
Mechanical and chemical intermediate cleaning
During the course of the year and independently of basic cleaning, it is advisable to take preventive measures for system hygiene at an early stage. FreiLacke recommends draining and cleaning the UF rinsing zones at regular intervals. The rinsing tunnel and the collecting trays of the rinsing zones should also be treated intensively mechanically and then chemically. The interval depends on the degree of production capacity utilization, the age of the system and the general degree of soiling. According to the company, an interval of one to three months has proven successful for many customers.
Implement continuous measures
As bacterial infestation can occur despite all measures, the bath values should be determined daily. The weekly routine also includes monitoring the bacterial situation using suitable dip and dish culture media. DipSlides have proven their worth here as they are easy to use and offer a wide range of bacteria. Sampling should take place at least in the paint tank, in the ultrafiltrate and in the last rinse before the ETL.
Modern coating systems contain significantly fewer solvents
New, more environmentally friendly coating systems contain significantly fewer solvents and can therefore be more susceptible to bacterial growth. Experience in recent years has shown that the ultrafiltrate rinsing zones and DI rinsing zones before the ETL were often the starting point for bacterial infestation. Weekly preservation of the UF rinsing zones can significantly extend the service life of the ETL tanks and prevent rapid infestation.