After the alkaline spray cleaning line heats up, foam in the tank accumulates along the spray pump suction; the nozzle pressure gauge needle keeps dropping, workpiece drag-out thickens, and both coating adhesion and cleaner addition come under pressure.
Chemi Tech offers the KM-502 series defoamer for alkaline spray-cleaning systems in hardware pretreatment; the dosage can be adjusted flexibly according to bath alkalinity and spray pressure. This grade is a silicone defoamer that resists strong alkali and acts fast, breaking foam without decay under the shear of the spray cycle. Combined with measured nozzle pressure and workpiece drag-out data, the suitable dosage of the KM-502 series can be determined.
Advantages of Chemi Tech Defoamer
Chemi Tech's KM-502 series defoamer is configured for alkaline spray cleaning lines. It acts fast — foam is broken the instant it re-enters the spray pump return; alkali resistance is outstanding, holding break capability as bath alkalinity rises; shear-stable, with anti-foam not decaying under spray-pressure fluctuations; compatibility with the cleaning-agent system is excellent, with no oil separation or wall fouling, keeping nozzles and filter screens clear; no residue interference on the rinse section, with an even water film on the workpiece surface; the dosage is economical, graded by bath alkalinity, and cleaner addition falls in step.
Industry Pain Points and Solutions
The foam problem in spray cleaning mostly stems from the combined effect of high-temperature alkaline liquor and high-speed spray-pump shear, ultimately concentrating in two places: nozzle pressure loss and workpiece drag-out.
After the spray pump suction draws in foam, the outlet pressure gauge needle keeps dropping, nozzle impact is insufficient, and oil in blind holes stays behind. The dosage of KM-502, graded by bath alkalinity, lets foam break first in the return tank.
Workpiece drag-out thickens, and the burden on the rinse section and electroplating pretreatment rises together. KM-502 acts fast, and the rinse-tank foam disperses before the workpiece enters.
Cleaner addition and waste-liquid treatment ultimately count into the per-piece treatment cost. Combined with changes in bath alkalinity and spray pressure, the dosage can be narrowed to an accountable range, directly lowering addition and neutralisation spend.
Typical Conditions and Verification
Customer case: a hardware electroplating enterprise in Zhejiang, applied to the pre-plating alkaline spray cleaning line.
After the line heated up, the nozzle pressure gauge needle dropped nearly a notch. Workpiece drag-out dripped along the edges, and the rinse-tank foam lingered for hours. The adaptation point was set by bath alkalinity: KM-502 as the line's defoamer, with the dosage graded step by step by alkalinity. Thereafter, nozzle pressure recovered stable; workpiece drag-out narrowed; the rinse-tank foam dispersed before entering, and coating-bond inspection no longer reworked.
FAQ
Once the line's alkalinity is raised, will the defoamer leave an oil film on tank walls and lines?
This has to be checked along two lines: component compatibility and wall-fouling tendency. KM-502 has completed comparative trials of nozzle pressure and workpiece drag-out on alkaline spray-cleaning conditions; within the recommended range it does not separate oil or foul walls, keeping filter screens and nozzles clear. The actual dosage is based on bath alkalinity, with spray pressure and bath temperature as corrections; Chemi Tech determines the suitable dosage by comparing nozzle pressure against drag-out volume.