New aircraft trim panel reduces noise level by 10 decibels / Amazingly better acoustics

Hamburg (ots) - 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