The article “Pretreatments: The Next Generation” in this issue discusses the technology, advantages and limitations of non-phosphate or low-phosphate chemistries for paint and powder coating pretreatment operations.
Most of these emerging technologies contain similar key components, coupling zirconium, vanadium, titanium or silicon-based compounds with an organic polymeric component to produce a finish equal to or better than that obtained using conventional iron phosphate pretreatments. And, they do it at ambient or reduced temperature, with minimal sludge generation.
Those are some pretty impressive operating benefits, but reduced environmental impact was the key driver when izzydesign, a manufacturer of office furniture located in Spring Lake, MI, switched its pretreatment process from a conventional phosphate to Houghto-Prep ZP from Houghton International (Valley Forge, PA). The company says it’s committed to manufacturing responsibly and to creating a safe and sustainable workplace environment for its customers as well as its own employees.
Houghto-Prep ZP is a proprietary zirconium phosphate, iron-rich conversion coating chemistry designed to promote paint adhesion and corrosion resistance. The material is said to reject oil extremely efficiently, allowing for continuous and complete removal with any oil removal system. It cleans and pretreats across a range of temperatures from ambient to 115°F. The company says no system heat is required in most cases. It is also said to exhibit low water usage requirements, including minimal rinsing, and can be made up with most water without need for reverse-osmosis or deionization. At izzydesign, the chemistry replaced the entire pretreatment process, from cleaning through conversion coating and sealing.
Because the solution works effectively at room temperature (versus the 140°F temperature required by the previous pretreatment product), izzydesign is also saving on energy costs. The company estimates energy savings of $20,000–$25,000 per year.
The reduced-phosphate chemistry also has cut izzydesign’s hazardous discharge to a level so low that water discharged from its treatment tank no longer requires federal, state or local water quality review. Prior to implementing the new pretreatment, the company was compliant with all local, state and federal discharge statutes. Local water and sewer authorities required a twice-yearly monitoring and reporting, but discontinued the practice after the pretreatment switch.
Similarly, the state of Michigan Department of Environmental Quality no longer requires the company to file a storm water permit. Water is discharged to a retention pond in front of the company’s headquarters, which provides a habitat for wildlife.