Sandwich element for the sound-absorbing inner cladding of means of transport, especially for the sound-absorbing inner cladding of aircraft

Abstract

A sandwich element for sound-absorbing inner cladding of means of transport, especially aircraft, comprising a three-dimensionally constructed core disposed between two substantially parallel cover layers is provided.

Sound transmission passages are incorporated in the core, and/or in at least one cover layer. At least one sound absorption layer is in the area of a cover layer at least in parts. Passages in the cover layers and core provide good sound absorption and heat insulation. The passages allow transmission of sound. The through channels and the preferably inclined installation of the sandwich element allow foreign bodies to be flushed out by, for example, a cleaning liquid or condensation. Possibly sufficient sound absorption can be achieved without the sound absorption layer. Ventilation of the core prevents the long-term presence of condensation, which could cause corrosion and/or rotting. A fire-retardant layer including metal particles may increase fire protection and electromagnetic insulation.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 12 / 227,569, filed on Nov. 19, 2008 which is a national stage of PCT / EP2006 / 004944 filed on May 24, 2006, the disclosures of each of which are hereby incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The invention relates to a sandwich element for providing a sound-absorbing inner cladding of means of transport, especially for a sound-absorbing inner cladding of aircraft, comprising a three-dimensionally constructed core structure which is disposed between two cover layers which run substantially parallel to one another at a distance.[0003]Sandwich panels of fibre-reinforced plastic materials are generally used for the inner cladding of aircraft fuselage cells for reasons of saving weight and because of the high strength requirements. The sandwich panels used commonly have a honeycomb-shaped core structure which is provided with cover layers on b...

AI Technical Summary

Benefits of technology

[0027]As the core structure is coated with a layer of intumenscent material, this layer is not only hardly flammable but, furthermore, the intumescent material, upon fire impact, may partly or completely close the passages and channels provided by the core. Thus, the closed passages and channels may prevent or reduce stack-effects and may therefore slow down fire propagation.

[0028]According to a further exemplary embodiment of the invention the fire retardant layer comprises a glass forming material. Such glass forming material may be an oxide that may readily form a glass layer upon heating. This glass layer may coat and protect the underlying portion

Problems solved by technology

As a result of the honeycomb-shaped structure being covered with the cover layers on both sides, the sandwich panels have a plurality of repeated units which are closed in themselves, of small volume and therefore not capable of drainage.

However, providing the possibility for air exchange between the external environment and the inner region of a sandwich panel may involve the risk of foreign bodies being incorporated and the penetration of moisture.

The presence of foreign bodi

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