Lufthansa Technik AG, Hamburg, worked to outfit luxury Boeing and Airbus aircraft with flame-retardant highgrade wood veneers that complied with the FAR 25.853 aviation standard. The spec dictates that materials (after 1 min of contact with flames) selfextinguish within 15 sec. And flames must also not exceed 15 cm in height. Flame retardants for wood, plastics, elastomers, and textiles already existed. But there were no halogen-free transparent coating systems available for Lufthansa's impending projects. The air carrier previously employed a TCEP-modified transparent coating that consistently met fire-protection requirements but wasn't free of halogens.
A solution to Lufthansa's quandary came from Alfred Clouth Lackfabrik GmbH & Co. in Germany whose specialties include developing polishable, flameretardant high-gloss varnishes for wood. Working with flame retardants from Lanxess Deutschland GmbH, the company concocted the right formulation from Lanxess's Levagard and Disflamoll line of halogen-free flame retardants. The resulting aircraft fittings employ glass fiber-reinforced honeycomb laminated with impregnated wood veneers. They are subsequently coated with an aliphatic, highly cross-linked polyurethane coating.
The Levagard and Disflamoll lines of halogen-free flame retardants can also be used on flexible PVC, phenolic resin, and synthetic rubbers. Disflamoll formulations as well find use in thermoplastics such as PC/ABS, cellulose acetate, and PUR foam.
Alfred Clouth Lackfabrik GmbH & Co., +49 69 890 07-0, clou.msg-at.net
Lanxess Deutschland GmbH, lanxess.com