Quick answer: Coagulant and flocculant have different and complementary functions in paint booth water. coagulant First, it removes the stickiness of the ink that falls into the water and forms small particles. flocculant Next, it binds these particles into larger flakes, which rise or sink and can be removed as sludge. Without one or the other, the treatment is incomplete.
In wet paint booths, the water curtain captures the overspray. But this paint doesn't disappear: it remains in the water. Without proper treatment with coagulant and flocculant, the paint sticks to the walls, clogs nozzles and pumps, generates bad odors, and forces the booth to be shut down for cleaning. Below, we explain what each additive does and how to use them together.
Why does paint booth water need treatment?
In a wet spray booth, air containing a mist of paint passes through a curtain or water scrubber. The paint becomes trapped in the water, which circulates in a closed circuit and returns to the booth. Without additives, this paint remains sticky and causes a number of problems:
- Incrustation: The ink sticks to walls, tanks, pipes, and nozzles.
- Blockage: Pumps and nozzles lose flow, and the water curtain becomes weak.
- Foam and bad smell: The water is degrading and the environment is getting worse.
- Maintenance shutdowns: Manual cleaning takes hours and interrupts production.
- Higher disposal costs: The sludge is mixed with the water, providing more volume for treatment.
Treatment with coagulant and flocculant transforms this ink into a sludge that doesn't stick and is easy to remove. This allows the water to circulate for longer. If you are still choosing between systems, see... the differences between dry and wet cabins.
What is coagulant and what does it do in cabin water?
The coagulant is the first additive in the treatment. The paint particles in the water have a negative electrical charge and remain dispersed, without clumping together. The coagulant has positively charged components that attract these particles and neutralize their charge.
In practice, the coagulant does three things:
- Removes the stickiness of the paint. This process is also called denaturation or "non-adhesion." The paint stops sticking to walls, tanks, and pipes.
- It destabilizes the particles. Without the burden that kept them separated, they begin to get closer.
- It forms microflakes. They are still small and thin clumps, which on their own are difficult to separate from the water.
The coagulant is dosed continuously or regularly, according to the amount of ink that enters the water. ISOGOL 550 Coagulant Additive, from Koria's treatment line, is indicated for polyester, polyurethane and alkyd paints and promotes rapid coagulation, facilitating the maintenance of the water system.
What is flocculant and what does it do to the cabin water?
The flocculant is added after the coagulant. The microflocs formed during coagulation are still too scattered in the water to be removed. The flocculant acts as a "bridge" between them: it joins the microflocs into large, firm flocs.
With larger flakes, separation becomes simple:
- In systems of flotation, The flakes rise and form a layer of sludge on the surface, which is removed with a scraper or sieve.
- In systems of sedimentation, The flakes sink and accumulate at the bottom of the tank.
The result is cleaner water to return to the circuit and a more compact sludge, with less water, which reduces the volume for disposal.
THE Flocculant Additive Koria works with water-based and solvent-based inks and optimizes sludge removal in flotation and wastewater treatment systems.
How coagulant and flocculant work together
Order matters. The treatment follows this sequence:
- The ink falls into the water. carried away by the curtain or the cabin washer.
- The coagulant acts as: It removes stickiness and forms microflakes.
- The flocculant acts as follows: It joins the microflakes into large flakes.
- The dregs are separated by flotation or sedimentation.
- Clean water returns for the cabin circuit.
If flocculant is added without coagulant, there are no microflocs for it to bind, and the ink remains sticky. If there is only coagulant, the microflocs remain loose in the water and the sludge does not separate well. Therefore, coagulant and flocculant work as a team.
The performance of both also depends on water quality. Very hard water or water with foam reduces the efficiency of the treatment. In these cases, the Hardness Additive It helps stabilize the water and reduce foam.
Coagulant vs. flocculant: a comparison
| Coagulant | Flocculant | |
|---|---|---|
| When it acts | First, as soon as the ink falls into the water | After the coagulant |
| What it does | It removes stickiness and neutralizes the charge of the particles. | Join the microflakes into large flakes. |
| Result | Non-sticky microflakes | Flakes that rise or sink |
| Problem that solves | Encrustation, clogging, and stuck-on paint. | Separation of sediment and water clarity. |
| If missing | Sticky ink in the system | Thin, difficult-to-remove smudge |
Signs that the water treatment is not working correctly.
Be aware of these symptoms in the cabin:
- Paint sticking to walls, tanks, and nozzles: Lack of coagulant or dosage below the required level.
- Sticky sludge, difficult to remove: incomplete coagulation.
- Cloudy water with fine particles that do not separate: Lack of flocculant.
- Excess foam: Hard water, pH outside the range, or excess additive.
- Bad smell: Degraded water that needs treatment or replacement.
- Nozzles and pumps clogging frequently: Inadequate treatment overall.
Any of these signs indicates that it's time to review the coagulant and flocculant dosage and the water quality.
How to dose coagulant and flocculant in a paint booth.
The correct dosage depends on the volume of water, the quantity and type of paint applied, and the water conditions. Some good practices:
- Control the pH. Additives work best within a pH range specified by the manufacturer. Measure frequently and correct when it goes outside the range. Read more about this topic on the Koria blog, in the post about pH control in cabin water.
- Monitor the water hardness. Hard water hinders coagulation and promotes foaming.
- Use a calculator. THE Koria coagulant calculator It helps to estimate the amount of additive needed for your system.
- Follow the technical specifications. Each product has its own dosage and application point guidelines. The ISOGOL 550 technical data sheet is available at [website address]. product page.
- Choose automatic dosing. A dosing device maintains a constant quantity and prevents spikes in product shortage or excess.
To delve deeper into the coagulation process, Kluthe, a manufacturing partner of Koria, has a Technical article on ink coagulation in industry. (in English).
Conclusion: coagulant and flocculant are a pair.
The coagulant dissolves the ink, and the flocculant collects it. Used in the correct order and with the water under control, they keep the booth clean, reduce maintenance downtime, and decrease the volume of sludge for disposal.
Koria has a complete line of wet-process cabin treatments: coagulant, flocculant, and hardness additive, plus technical support to adjust the dosage to your process. Talk to our team and find the ideal combination for your cabin.
