26 Dec The monotony of drumming
Some people find that the monotonous noise produced by train wheels on the tracks makes them sleepy; others struggle to cut out external influences of this kind in order to sleep or work in a concentrated manner. Sound insulation and the reduction of structure-borne noise in rail vehicles to give passengers a relaxing journey is therefore a big challenge for engineers. Although some components can be produced from alternative materials, it is often not possible to avoid thin-walled sheet metal constructions, where significant vibration is unavoidable. This causes irritating background noises.
So that peace and quiet is not left by the wayside: a flame-retardant sound deadening solution which absorbs structure-borne noise in trains is essential to passenger comfort… It’s not only speed, comfortable seating and legroom that are important, so too does a feeling of spaciousness within the train compartment or aircraft cabin. Passengers who wish to work or rest undisturbed during their journey can choose quiet compartments in trains, where loud speaking, mobile phone use and other noisy activities are prohibited. In order to reduce the structure-borne noise of the rail carriages themselves and therefore to create the quietest-possible environment inside, many rolling stock manufacturers use sound deadening.
Structure-borne noise absorption
Large-scale sheet metal is often used in the manufacture of railway carriages. These vibrate when the train is moving, producing noise. This structure-borne noise spreads almost unhindered and without loss in metal vehicle components. These sound waves are then transmitted to the air so that the sound occurs as an audible noise inside the car. In order to prevent this noise generation, which can be irritating, homogeneous layers are placed between the individual elements for internal damping. The ideal layer penetrates the material to which it has been applied, the vibrational energy of the material is largely eliminated because it converts high-frequency vibrations into low-frequency ones. As a result, rail vehicle bodies emit less noise to the air in their interior space.
The metal sheets used in the interior construction of carriages – for cladding for example – are covered in sound-deadening materials to dampen the noise. And now paint and coating experts Griwecolor Gmbh have produced a coating classified as a non-flammable product, class A2, according to DIN EN 13501-1.
Decades of know-how in the noise reduction of rail vehicles and façade elements or windows, has inspired further development with regard to reduced smoke density and smoke gas toxicity as well as acoustic effectiveness and flame retardancy and the AN2-750/EU has been classified as a non-combustible product, class A2, in line with DIN EN 13501-1; it has also passed the toxicity and smoke gas density test in line with the DB Systemtechnik specifications without a hitch. It therefore meets the requirement set R1 for HL1, HL2 and HL3 for application in rail vehicles with regard to smoke development and toxicity. Like the two variants already on the market, the sound deadening solution based on aqueous synthetic resin dispersion is also hydrophobic and solvent-free.