The PPG Coatings Services electrocoating (e-coat) process offers many advantages, starting with an appropriate pretreatment, followed by careful electrocoating, and finishing with precise thermal curing.
More industries than ever before are selecting electrocoating for their excellent finish quality, high productivity, cost-effectiveness, high-efficiency and versatile technology options.
Even better, electrocoating offers an "environomic" solution: no heavy metals, no HAPS and low VOCs.
How Electrocoating Works
Electrocoats readily conform to complex configurations and yet maintain engineered tolerances on parts ensuring intended operating functions. Some examples include internal surfaces, deep recesses, weldments, fasteners, small parts, large parts, and uniform coating (with no sags or runs).
The fundamental physical principle of this technology is that materials with opposite electrical charges attract one another. An electrocoat system applies a DC charge to a metal part immersed in a bath of oppositely charged paint particles. The paint particles are drawn to the metal part and paint is deposited on its surface, forming an even, continuous film over every curve, crevice and corner, until the electrocoat reaches the desired thickness.
At the desired thickness, the film insulates the part enough that the electrical attraction stops, and the coating process is complete. Depending on the polarity of the charge, electrocoat is classified as either anodic or cathodic.
The electrocoat process can be divided into four distinct steps:
- Step one is the pretreatment process, during which metals are cleaned and phosphated to prepare the surface for application of the electrocoat.
- In step two, the electrocoat bath is applied using ancillary and process control equipment. The electrocoat bath consists of 80% - 90% deionized water and 10% - 20% paint solids.
- Step three is the post-rinse, where excess paint solids are returned to the tank.
- Step four is curing in the electrocoated part in the bake oven. The minimum bake schedule is 20 minutes with a part temperature at 375°F for most electrocoat technologies.
Substrates Electrocoated: Cold Rolled/Hot Rolled Steel, Galvanized Steel, Iron Castings, Zinc Castings, Copper/Brass, Conductive Composites, Aluminum Extrusions and Castings, NiZn Plated Steel, Stainless Steel, Magnesium, and Chrome Plate.
Selecting the proper pretreatment is essential to success. PPG Coatings Services can deploy multiple technologies to meet most OEM specifications, including zinc- and iron-phosphating, impellers and air blasters, chrome conversion coatings, and chrome and non-chrome sealers.
The PPG Coatings Services Equipment Division designs, builds and installs the majority of its coating production and support equipment. We satisfy customer demands with
- Quick response times
- Specialized coatings systems and processes
- High production capability
- Versatile equipment options
- Large- and small-part coatings capability.
Electrocoating produces the ideal base for a variety of topcoats, yielding a “dual application advantage,” that results in demonstrably more decorative and durable finishes. As a premier applicator, PPG Coatings Services has the technology and technical expertise needed to pretreat and electrocoat virtually any metal substrate in-house.
Whatever the coating objective – if it can be met with electrocoating, powder coating, liquid painting or a combination of each – you can trust the protective coating specialists at PPG Coatings Services. To take advantage of the complete PPG Coatings Services process, from research and development to delivery, call 877-786-9670 today.