The challenge

Before the painting process of car bumpers can begin, the plastic parts must go through a washing process in order to remove dirt, debris, residue and slight oil or grease contamination.

The conventional washing process involves many stages:

• Phosphoric acid wash,
• Different rinsing stages,
• Rinsing with deionised water.

The production of ultra-low conductivity water is very costly and there was no way to recuperate this water for reuse. Most of it was sent to drain. The company attempted to recycle this water, but after one year of operation, biofouling and biofilm had become a significant problem in the piping network.

Additional cleaning had been carried out in order to eradicate this problem, but it resulted in recontamination the next week.

The solution

The company introduced Huwa-San TR-50 in order to remove all biofilm to enhance the water quality. The disinfection procedure was carried out in 2 steps.

• The first step was to remove the biofilm from the pipes. A shock dosage of Huwa-San was advised, removing a considerable part of the built up biofilm in only a few hours’ time. When all of the biofilm and biofouling had been removed from the pipe system, water was produced in the correct quantity and quality.
• Second, after the shock treatment, Huwa-San TR-50 was dosed continually in the main tank at a contant dosage rate. The final rinse water could then be safely collected and pumped back to the water purification system for recleaning. It can then be reused as virgin deionised water.