PPG Industries and AkzoNobel each have begun distributing two new coatings for the aerospace industry, one an electrocoat primer and the other a chrome-free aircraft pretreatment.
The Aerocron primer from PPG’s aerospace coatings group is the first e-coat primer for airframe manufacturers and subcontractors, says Mark Cancilla, PPG’s global platform director for aerospace coatings. He adds that the product has better corrosion protection for metal parts because e-coating enhances part coverage over a conventional spray primer.
“As electrocoating was for the automotive industry, the process is truly revolutionary for aerospace primer application,” Cancilla says. “PPG developed Aerocron electrocoat primer to meet the application needs of airframe manufacturers as well as the operating and maintenance requirements of airlines and other aircraft operators.”
PPG’s Michael Pawlik told a conference at the Advanced Surface Engineering Technologies for a Sustainable Defense (ASETSDefense) a while back that a new generation of aircraft substrates combined with environmental regulations present challenges to developing new materials and processes for painting.
Immediate Part Handling
He particularly pointed to e-coat’s ability to allow for immediate part handling after thermal cure (30 min, 200°F), so there is no dry-to-touch, dry-to-tape or dry-to-fly restrictions.
Pawlik says Aerocron easily passed all its required military tests, including fluid resistance on test material Skydrol LD4, Jet A fuel and Turbo 2380 engine oil
Robin Peffer, PPG’s senior research chemist at the company’s Coatings Innovation Center in Allison Park, Pa., was instrumental in the development of Aerocron, Cancilla says.
“Aerocron electrocoat primer coats parts uniformly, even in the recessed areas of complex-shaped parts, and at reduced weight, which translates to long-term aircraft operation savings,” Peffer says.
Andreas Tolz, aerospace coatings technical projects manager for Europe, who is based at the company’s Gonfreville, France, aerospace coatings facility, leads the commercial introduction of Aerocron in Europe.
“Aerocron electrocoat primer is formulated to help applicators get the most from the electrocoat process, providing a real breakthrough for the aerospace industry in several ways,” Tolz says. “For aircraft manufacturers and subcontractors, the electrocoat process can be fully automated and offers increased material utilization, making it a good ‘green’ choice. For their customers, it adds value to finished aircraft by providing better corrosion protection and lighter weight.”
AkzoNobel and Pantheon
AkzoNobel’ Metaflex SP brand is a result of a two-year partnership between AkzoNobel Aerospace Coatings and Pantheon Enterprises, the maker of chrome-free aircraft pretreatments.
It was developed to meet the AMS3095 specification as part of a number of AkzoNobel Aerospace coatings systems, says Kevin Fleetwood, Airbus director at AkzoNobel.
“We decided to work with Pantheon following an extensive testing regime where we looked at the available technologies in the market and carried out a large benchmarking program,” he says. “We found that, in filiform corrosion testing especially, the Pantheon technology showed significantly better corrosion resistance in combination with our systems. This led to us deciding not to develop our own technology from scratch, but to work with Pantheon to develop a pretreatment that delivers what we consider to be superior corrosion resistance compared to anything else currently in the market.”
Laura Roberts, CEO of Pantheon Enterprises, said the development and commercialization of Metaflex was aimed at the AMS3095 specification.
“It represents a significant milestone in the painting industry,” she says.
Michela Fusco, market segment manager MRO for AkzoNobel Aerospace Coatings, says the big difference is that, where before permanently embedded contaminants in the pores of the metal would repel standard chromate conversion coatings resulting in frequent adhesion failures, the Metaflex SP technology promotes paint adhesion directly to permanently embedded contaminants.
“We are confident that, on top of giving superior corrosion resistance and reduced emissions from the painting process, we should be able to reduce process time for both Washprimer users and SolGel -type users in the aftermarket,” Fusco says.
For information on PPG’s Aerocron, please visit ppgaerospace.com. For information on AkzoNobel’s Metaflex SP, please visit anac.com.