New Aircraft Trim Panel Reduces Noise Level by 10 Decibels

Amazingly Better Acoustics

HAMBURG, Germany, April 6, 2011 - Aircraft noise is one of the biggest environmental concerns. But in the
interior of aircrafts, passengers and the crew also have to be relieved from
noise emissions. At the Expo 2011, the Pelzer Consult GmbH presented its
worldwide novel aircraft trim panel that reduces the noise level in the
interior by up to 10 decibels.

The supplier of VIP aircrafts will be excited about it: Thanks to the
high reduction of the noise level, the interior noise and speech
intelligibility has been appreciably improved. However, due to stricter
health guidelines, the new trim panels are also suitable for personnel rest
rooms or the First Class areas in commercial aircrafts.

In order to measure all important acoustic parameters, an acoustic test
bench was especially developed which was used to acoustically measure whole
exterior aircraft walls in every detail including interior trim panels. The
evaluation resulted in the concept of a novel aircraft trim panel, which
leaves behind substantially less noise energy.

Conventional trim panels use sandwich panels with closed covering layers,
which are a big acoustic drawback. Closed honeycomb sandwich panels will
result in an undesired loudspeaker effect: The rigid honeycombs link up those
covering layers prompting vibrations and radiating disruptive airborne noise.
"It is a paradox. The conventional closed sandwich panels make for ideal flat
loudspeaker diaphragms!", says Hans-Peter Keller, the Research and
Development manager of the Swiss Pelzer Consult. "We got rid of the
loudspeaker effect. For our panels, we use acoustically open covering layers.
This allows the sound to pass and to be better absorbed. An additional
decoupled sealing film will prevent, by the way, that airborne noise will
make it through our open honeycombs from the outer wall of the aircraft into
the interior. With the weight being the same, the acoustics is amazingly
better."

It is the first time that thermoplastic, 100% recyclable 3-D supporting
material has been used requiring only a fraction of the production time.

Aircraft Composites Consortium - a merger of the Swiss companies Plastika
Balumag AG and Pelzer Consult GmbH as well as the German Tubus Bauer GmbH -
is the only platform in the world that is able to mass produce the trim panel
for which a patent application has been filed.

    Contact

    Hans-Peter Keller
    Manager R&D
    Pelzer Swiss GmbH
    mobil +49-172-2744521
    keller@pelzerswiss.ch

Contact: Hans-Peter Keller, Manager R&D, Pelzer Swiss GmbH, mobil +49-172-2744521, keller at pelzerswiss.ch .