Jan.2017. Acoustic advantages
The break of thermal bridge, is distinguished by improving the thermal transmittance of its system in addition to being a key element in the processes of powder coating and anodizing. However, the market is constantly in motion and in the process, trends are emerging that drive the industry to be in continuous search for improvements or ways to adapt to new regulations. One of these tendencies leads us to a relatively new area for polyamide strips: acoustic (since 04/04/2009 it is mandatory to meet the DB-HR: 'Noise protection' of the CTE).
Technoform Bautec has carried out a project to satisfy this new need of the market. The project, carried out by the technical team of the different Technoform branches in Europe, together with Ensatec, for the validation of the data obtained, has elaborated a comparative study on the effect of the strips of PA66 GF25 on acoustic attenuation of window. For this, comparative tests of acoustic insulation to aerial noise obtained between different panels with cold aluminum and aluminum with thermal break of polyamide 6.6 reinforced with 25% of glass fiber were carried out.
In order to carry out these tests, panels of dimensions 1x1 meters were tested in accordance with the standard UNE EN ISO 10140-2: 2011.
The comparison of results is as follows:
The Rw (C; Ctr) weighted sound reduction index gives approximate values:
RA = RW + C (Considering the pink noise or railway or train noise)
RAtr = RW + Ctr (Considering traffic noise - cars or aircraft)
Considering that the higher the value of RAtr the greater the sound insulation will have the window or door.
The data of this test conclude that a window of aluminum with rupture of thermal bridge, with Technoform Bautec strips of polyamide 6.6 reinforced with 25% of glass fiber, improves the acoustic behavior to the traffic noise of a window compared to the one that would have a window of cold aluminum in a range that goes between 3dB up to 5dB.
These results are based on tests performed exclusively with Technoform Bautec strips, therefore the scope of these values is limited to this brand.
The acoustic behavior of the window also influences other parameters such as air permeability or embedded glass. The greater the permeability, and the better glass the window has, the better acoustic attenuation is obtained in the set.
This data can be used to decide on the use of (thermal bridge break) in the system, and therefore improve its performance.