Aircraft manufacturer uses nitrogen to produce carbon fiber wings
Herrsching, 24. September 2020
On site generated nitrogen prevents fires in the manufacture of wings in autoclaves
One of the world's leading aircraft manufacturers produces wings for a family of passenger aircraft in its plant. These are made of CFRP (carbon fiber reinforced plastic) materials at almost 200 degrees Celsius in ovens, so-called autoclaves. To prevent the materials from igniting at these high temperatures, nitrogen is introduced into the furnace. The low-reaction, inert protective gas is generated in the required quantity directly in the factory using an INMATEC nitrogen generator PNC 9600.
The immense competitive pressure in the aviation industry is forcing airlines to cut operating costs. The aircraft industry has adapted to this and increasingly offers energy-saving and lighter aircraft models. The use of CFRP materials enables the production of ultra-light and at the same time extremely stable components. The finished CFRP components save enormous weight in modern aircraft and thus save large amounts of fuel. Therefore, CFRP is used in particular in the production of wings.
For this purpose, robots put numerous layers of fiber ribbons on top of each other, which are impregnated with resin. After the fibers have been deposited, the wing shell is pushed into the autoclave, which is more than 30 meters long, using a low-loader. Here the carbon fiber reinforced component hardens under heat and pressure for several hours. At the high temperatures of around 200 degrees Celsius, there is a risk of the materials igniting. To prevent this, nitrogen is pressed into the furnace as a protective gas. An oxygen-reduced atmosphere with a nitrogen content of approx. 84% or an oxygen content below 15% efficiently prevents fires.
In order to avoid production downtimes, the required amount of nitrogen must be available at all times. An INMATEC nitrogen generator PNC 9600 produces up to 655 m3 of nitrogen per hour with a purity of 95%, depending on requirements. After a successful test phase lasting several months, the manufacturer decided to purchase the Inmatec generator. At the moment, two more PNC 9800 generators are in production at Inmatec, which will produce a further 1200 m3 / h of nitrogen for the inertization of the autoclaves after delivery at the customer's plant.
