Autophoretic Coating Process is a waterborne process in which organic polymeric emulsion gets chemically deposited on the surface of a clean metal substrate. Basics of Autophoretics: Also known as autodeposition, A-coat or AP. It is a waterborne process which depends on chemical reactions between a ferrous. AUTODEPOSITION is a waterborne process which depends on chemical reactions to achieve 5 — [email protected] Chemical Coating. Stage No. 6 — Plant.
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Autophoretic Coating Process
This process has been in commercial use since Since its inception, this unique process has been employed to coat billions of square feet of surface. Presently, there are numerous installations in operation, both captive and job-shop, coating a variety of fabricated steel parts for the orocess and general industry markets.
The bath viscosity is close to that of water with little or no organic solvents in the coating bath. The mildly acid bath liberates a small amount of iron from the steel parts being immersed, causing an immediate surface reaction that releases iron ions.
These ions interact with the latex in solution causing coating deposition on the surface of the steel parts. Prcess newly deposited organic film is adherent yet quite porous.
Description of Autophoretic®
This allows the chemical activators to diffuse rapidly in the film and etch the surface of the metal. The continuous formation of coating provides a film with a high degree of surface protection and corrosion resistance.
The coating thickness of the autodeposited film is time and temperature related. Initially, the deposition process is quite rapid, but slows down as the film increases in thickness. Typically, film thickness is controlled from 0.
This allows the coating dispersion to flow into and around the most complex shapes. Unlike coating processes that require a charge to deposit the coating i.
This diffusion control leads to a uniform coating thickness on complex shapes procfss in recessed areas. Latex films form by coalescence.
On leaving the bath, the coating consists of two layers; one is a very cohesive reacted layer; while the other is composed of undeposited excess polymer and activator from the bath. The chemical reaction continues in the second layer, which results procesa film deposition and increased film thickness instead of solids loss to dragout. This unusual feature strongly limits carryover of coating chemicals into the rinse tanks and greatly reduces the demand for waste treatment. The elimination of proceess stages leads to considerable savings in required floor space, energy, and operating costs, as well as the total elimination of toxic metals from the process.
Considerably lower temperatures are required to cure the autodeposited parts.