We have observed how the density, thickness and structure of laboratory and commercial boards affect their sound absorption and insulation; so as the acoustic properties of panel systems composed of such boards. As for commercial construction and insulating materials, chipboard, OSB, fibre, veneer and insulation boards were used, as well as lightweight composite boards with a cote of paper honeycomb. We constructed 2 three-ply panel systems. In each, the external plate was made of the same material. The outside boards consisted of particleboard, construction, veneerboard and OSB board, while the core was made of a classic insulating plate and a laboratory cellulose board. The boards and systems were tested in a chamber divided into 2 spaces, whose interior was laced with plamfone. One area of the chamber contained the sound source and the other one the receiver. A panel system was tested in 3 steps. Firstly, we tested the first layer, then added the core and in the last step the last layer as well. We have found that the behaviour of the boards depends on their structure and density. The results are shown in relation to the low, medium and high frequency range. Boards with a dense outer layer are better at reflecting sound and worse at absorbing it. Less sound passes through denser, thicker and more homogenous boards (eg. veneer), while it spreads more easily through thin boards because of their lower rigidity. Less dense boards absorb sound more easily into the interior because the board surface is more porous and more susceptible to absorption. Good absorption of panel systems and thus good noise insulation is provided by thicker and less dense boards with uniform structures.
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