In spray painting workshops, the water curtain booth is the core equipment for intercepting paint mist. But many operators have encountered this scenario: a thick layer of foam floats on the surface of the water curtain flow, and the foam carries paint residue as it overflows the circulation tank, not only dirtying the floor but also causing the water pump to draw in air and cavitate, sharply reducing spray effectiveness. Even more troublesome, foam accumulates in the paint residue separation area, preventing paint residue from settling properly, accelerating water quality deterioration, and ultimately forcing frequent shutdowns for water changes.
The root causes of this kind of problem usually lie in two aspects: first, the surfactants and resin components contained in the paint generate stable foam under circulation shear; second, the circulating water lacks effective foam-breaking substances. Many defoamers on the market are either not durable, with foam reappearing just a few hours after addition, or they cause oil slicks to drift and, in turn, contaminate the paint surface.
The water curtain booth water treatment defoamer launched by Chemi Tech is not simple physical defoaming but is based on the principle of interfacial regulation. The product can rapidly reduce the elasticity of the liquid film and destroy the bimolecular film structure of the foam, causing bubbles to collapse at the initial stage of formation. In addition to defoaming speed, it places greater emphasis on the persistence of foam suppression: under normal circulation conditions, a single addition can maintain a low-foam state for more than 8 hours.
The specific implementation steps are divided into three:
1. Measure the current circulating water volume and bubble conditions. Take the water curtain booth with the same number and record the foam layer thickness and water color.
2. At a ratio of 200-300 mL per cubic meter of water, add the defoamer directly into the circulating water tank or at the water curtain inlet. The initial dosage can be close to the upper limit; observe the foam subsidence after 1 hour, and if small localized bubbles remain, add another 50-100 mL.
3. Establish a dosing standard. Check the foam condition once per shift (8 hours), and when the foam layer again covers more than one third of the water surface area, add 30-50 mL of defoamer. At the same time, regularly clean the residue collection tank to avoid secondary foaming caused by accumulated paint residue.
Take a furniture manufacturer as an example. The factory has 6 water curtain booths, and its spray painting line runs 16 hours a day; in the past it needed to completely change the water twice a week, with each shutdown lasting 3 hours. After using the Chemi Tech defoamer, the water change cycle was extended to once every two weeks, reducing downtime by 6 hours per week, and a single piece of equipment saved more than 8,000 yuan per year in labor and wastewater treatment costs. Moreover, because the foam was effectively controlled, the moisture content of paint residue dropped by about 20%, and the cost of recycling dry residue was accordingly reduced.
If you are currently troubled by water curtain booth foam and have tried other products without good results, you may wish to start with this solution. Chemi Tech provides free samples and on-site application evaluation; you only need to provide operating condition parameters and a water quality sample to receive targeted dosage recommendations.