Masking paints for airbus

Citation

(2008), "Masking paints for airbus", Aircraft Engineering and Aerospace Technology, Vol. 80 No. 5. https://doi.org/10.1108/aeat.2008.12780ead.028

Masking paints for airbus

Article Type: Materials From: Aircraft Engineering and Aerospace Technology: An International Journal, Volume 80, Issue 5

RELIUS, part of BASF’s Coatings Division, provides a special masking paint to shave millimetres off Airbus parts.

The large aluminium parts used in aircraft construction, which are thin to begin with, are generally slimmed down through etching with chemical solutions. In order to ensure that only the desired spots are chemically “milled”, the experts at RELIUS have specially developed a solvent-free two-component masking paint for the Airbus plant in the northern German city of Nordenham. The paint reportedly hardens quickly. It is said to protect the aluminum substrates as the parts are dipped in sodium hydroxide solution. Weight is reduced only on the surfaces that have not been coated with the special paint.

RELIUS’ two-component masking paint is applied prior to the chemical milling process. A special spray unit is used to completely coat the airplane parts with masking paint. After 30 min of drying time, a computer-operated laser cuts the dried coating following a pre-determined geometric pattern. The cut edges of the groove serve as a natural seal, eliminating complicated sealing work. The paint on the laser-cut spots can be stripped off easily by hand.

Then the entire part takes a dip in a sodium hydroxide solution. The uncoated areas are etched by the solution and thinned down precisely to the millimetre. With this method, the aluminum is reduced from a starting thickness of 6 mm to a mere 2 mm. All other areas are said to be safely protected with the two-component masking paint, retaining their original thickness. Once the chemical milling process has been completed, the masking paint is removed from the part completely.

The method involving masking paint to chemically mill aluminium has been around for over 35 years. So what makes RELIUS’ two-component masking paints so unique? “What’s special about our masking paint is that it’s solvent-free and hardens quickly,” explains Dieter Hohnholz, head of New Technologies at RELIUS, who played a major role in the development of the product. “There’s no other product like it on the market.” The paint film can be stripped off completely, without leaving any traces, and it does not have to be disposed of separately as special waste. On top of that, the Airbus plant in Nordenham has been able to completely shut down its solvent recovery unit.

The masking paint consists of two components: base paint and hardener. They are delivered separately and are mixed in a special two-component spray unit just before application. The new RELIUS paint is said to require just one spraycoat, as opposed to the two or three spraycoats needed when conventional masking paints are used. The short hardening time of 12-3 s means that vertical and round components can also be coated easily. After a total drying time of just 30 min, the next step in the production process can be started. This innovation saves valuable time - taking just a fraction of the four hours that used to be required.

The long development period of eight years has paid off. The Airbus plant in Nordenham is using the innovative product on the fuselage of the A380, the world’s largest commercial airliner. Every week, RELIUS ships two containers of masking paint and hardener to Nordenham.

For further details please contact: BASF Coatings AG, Tel.: +49 2501 3160, Fax: +49 2501 14 3750.