A sound absorbent panel (10) consists of a sheet (12) of wood-based material comprising a core of compressed material (10) and balanced veneers (18,20) on two sides, and at least one sheet (14) of non-woven fabric made of sound absorbent material glued to one side. An improved sound absorbent effect superior to the effect that can be obtained with the two separate elements is achieved.
The invention relates to the field of furnishing panels. Known and already used are furnishing panels with through holes consisting of a high or medium density central layer of wood fibre or wood pulp or the like and a veneer on the two larger surfaces. One type of such panels is marketed by Locatelli Laminati SaS di Locatelli Uberto & C. These panels have a thickness of 6 mm or less. They are generally used for decorative purposes, for cupboard doors, room dividers and generally where it is wished to allow a certain passage of light and air and a partial vision.
Also known are sound absorbent materials in sheets, for example non-woven fabrics, foams and the like, whose sound absorbing power, however, is significant above 20 mm.
An object in the building field is to obtain increasingly good sound absorbing effects with a relatively small bulk and low weight.
The invention, as defined in claim 1, solves the problem posed above and provides excellent sound absorption with a little thickness and a good aesthetic appearance.
The new panel comprises a core layer of compressed wood material coated on each side with wood veneer, this layer having through holes, and a layer of sound absorbent material, comprising a sheet of non-woven fabric, glued to a veneered surface. The through holes can be square, rectangular or round in shape, preferably with a void to solid ratio of not less than 15%.
The invention achieves the above mentioned objects.
Examplary embodiments of the invention will be given below with reference to the appended drawings in which they are illustrated and in which.
The panel of the invention is indicated as a whole with reference numeral 10. It comprises a layer 12 of wood or wood type material and a layer 14 of sound absorbent material. The layer of wood material 12 comprises a core 16 of sound compact wood fibre or the like, that is to say, with a density from 500 to 1100 kg/m3 and two sheets of veneer on the larger surfaces, indicated respectively with 18 and 20. The layer 12 of wood material has an arrangement of through holes 22, in this case a regular arrangement of square holes with a void/solid ratio of about 25%. Obviously the shape of the holes can be different, for example round, polygonal, etc. The holes in the layer 12 are covered or closed, on one side of the wood layer, by the sheet of sound absorbent material 14.
The layer of wood is preferably 0.5 to 1 mm thick.
The sound absorbent material 14 can be a commercially available sheet material, for example a non-woven fabric in polyester, and/or cellulose, and/or polypropylene, etc. In addition to the sheet 14, a further sheet or plate 24 of sound absorbent material (Figure 3) can be applied to the panel to improve its performance. The sheet 14 and the sheet 24 can be applied in any known manner, for example by gluing.
It has been found that the sound absorbent panel thus created has particularly high levels of sound absorption, superior to that which might logically be expected from a combination of the two basic elements (panel with holes and sheet) and superior to those that can be obtained with known panels of the same thickness.