Zirconium Conversion Coatings
Formulated to replace traditional iron phosphate, these products require very little heat (80 ºF)to deposit an inorganic conversion coating. Conventional iron phosphate products, on the other hand, can require temperatures of 130-160oF. Another benefit of this new technology is usage; a maximum of about 2% by volume, for the stand-alone coater, is needed in the bath compared to approximately 2-4% by volume with conventional iron phosphates.
These types of coatings provide a microcrystalline surface in the nanometer (10-9m) range and require a short contact time of 15 to 30 seconds. Conventional iron phosphate coatings are usually in the micrometer (10-6m) range and require at least 45 to 60 seconds contact time. The "nanocrystals" formed increase the surface area of the substrate thus enhancing paint adhesion, corrosion protection and consequently salt spray results. These zirconium conversion coatings do not require a non-chrome post treatment seal to achieve high performance adhesion, under film corrosion and salt-spray resistance.
These new technology coatings also contain no regulated heavy metals and eliminate phosphate from the process bath. Sludge is also reduced to a minimum while waste treatment costs and other effluent issues are greatly diminished. Reduced sludge formation results in considerably lower maintenance costs since fewer bath dumps are needed and the incidence of plugged nozzles and other problems are reduced. Rinse water consumption is also reduced because of the lower amount of total dissolved solids present in these new coating baths. Lower total dissolved solids means less rinse water overflow is needed to maintain proper rinse integrity.

Advantages of Zirconium Conversion Coating
  • Increased Corrosion Resistance
    • Salt Spray Performance
  • Reduced Environmental Impact
    • Phosphate Free
    • No Regulated Heavy Metals
    • Reduced Carbon Footprint
    • Less Acidity than conventional Phosphates
  • Reduced Wastewater Treatment
    • No Phosphates
    • No Regulated Heavy Metals
    • Less Sludge
    • Easier to Neutralize
  • Improved Maintenance
    • Less Scale
    • Low Foaming
    • Minimal Nozzle Cleaning
    • Minimal Sludge
    • Less Frequent Dumping
    • Less Down Time
  • Reduced Operating Cost
    • Less Downtime
    • Low Operating Temperatures
    • Reduced Fines from Municipalities
    • Less Hazardous Waste
    • Lower Chemical Usage
Increased Corrosion Resistance
The corrosion resistance performance of these inorganic conversion coatings is compared below to conventional iron phosphate coatings (organic accelerator) with TGIC polyester and hybrid powder paint systems on cold-rolled steel and aluminum substrates.
Paint SystemSubstrateZirconium Conversion Coating
2% conc., 80F bath,
30 seconds contact time		Iron Phosphate Conversion Coating
4% conc., 140F bath,
60 seconds contact time		Salt-Spray Exposure
(ASTM B-117)
TGIC PolyesterCold Rolled Steel0.5mm creepage from scribe1.8mm creepage from scribe504 hours
TGIC PolyesterAluminum0.2mm creepage from scribe1.0mm creepage from scribe1008 hours
HybridCold Rolled Steel2.0mm creepage from scribe4.3mm creepage from scribe504 hours
HybridAluminum0.4mm creepage from scribe2.2mm creepage from scribe1008 hours
Test panels were prepared and tested according to ASTM B-117 and evaluated according to ASTM D-1654 Method 2. Ratings were taken of the average creepage failure from the scribe mark after a predetermined number of hours of exposure.
Reduced Environmental Impact
environmentThe Zirconium conversion coating greatly reduces the environmental impact over conventional iron phosphates. These products contain no phosphates, or regulated heavy metals. With lower operating temperatures these products decrease fuel consumption therefore reducing carbon dioxide emisions. Due to the technology, the acidity level is reduced requiring less neutralization. The solid content of these products compared to iron phosphate is minimal. This helps reduce the amount of total waste from the system. The iron phosphate sludge creates a lot of solid waste to be disposed of.
Reduced Wastewater Treatment
The Zirconium conversion coatings reduce the amount of wastewater treatment required to discharge spent bathes to sewer. There are no phosphates or regulated heavy metals to remove so the sludge volume is reduced due to the lack of these contaminates. Treatment cost and sludge volume generated is further reduced when inorganic coagulants are not required to remove these contaminates. This combination of lower solids in the washer bath and lower treatment requirements greatly reduces the chemical treatment cost and the cost of sludge disposal. The chemical treatment cost is lowered again since the alkalinity required to neutralize the waste stream is reduced due to the low acidity level of the bath.
Improved Maintenance
nozzles Scale and sludge are common problems with iron phosphates. Scale can clog nozzles (see picture) restricting water flow and causing improper coverage on the parts. The zirconium conversion coating provides a cleaner system. Customers have experienced minimal sludge and scale. There is less downtime of the washer, since operators do not have to clean nozzles as frequently, to clean the screen to the pumps. Our conversion coatings can be used over 1 year without dumping. These conversion coatings produce little to no foam.
Reduced Operating Cost
Another big advantage of this technology is it saves money. Lower fuel bills due to lower temperature, more production output due to less down time because of maintenance, less waste treatment needed, possibly lower fees from municipalities, and lower usage rate make these products reduce overall operating cost.
For more information about our products contact us at sales@enviroserveinc.com
Other Related Documents