BE384935A

BE384935A -

Info

Publication number: BE384935A
Authority: BE
Priority date: 1930-09-24
Also published as: FR716969A; DE600996C; NL34827C

Description

       

  "Perfectionnements apportés aux revêtements de cloisons 

  
absorbant les sons". 

  
On a déjà utilisé, comme revêtement absorbant

  
les sons, des matières fibreuses, telles que la laine 

  
d'asbeste, la laine de bois ou matières analogues, et

  
cela comme garniture pour des briques creuses avec paroi

  
extérieure perforée ou en les introduisant dans un inter-

  
valle laissé entre la cloison et des plaques d'appui

  
perforées rendues solidaires de ladite cloison. Dans

  
les deux cas, il est nécessaire de prévoir des moyens

  
auxiliaires pour maintenir les matières fibreuses en

  
place. 

  
Conformément à la présente invention on évite

  
 <EMI ID=1.1> 

  
des matières fibreuses cimentées ou mastiquées et qui

  
ne reçoivent aucun enduit. De la laine de bois cimentée l'aide de ciment Sorel a donné des résultats particulièrement avantageux.

  
On peut fabriquer sur place le revêtement en se servant d'un coffrage approprié ou on peut également le constituer à l'aide de plaques, fabriquées à l'usine,

  
 <EMI ID=2.1> 

  
former une surface continue. Le revêtement, obtenu selon l'invention, peut être établi d'une manière bien plus économique que les revêtements connus; il peut être plus aisément mis en place et est, en outre, plus efficace du fait que les moyens de soutien, qui influencent l'absorption du son, n'existent pas.

  
De plus, les matières fibreuses cimentées con-

  
 <EMI ID=3.1> 

  
larges pores alors que de telles matières, quand elles ne sont pas reliées entre elles, tassent après un certain temps.. 

  
L'effet fortement amortisseur du son, obtenu à l'aide d'un revêtement non enduit et constitué par de la laine de bois cimentée, résulte du fait que le matière comporte de larges pores dans lesquels peuvent pénétrer les ondes sonores. Les quelques ondes sonores, qui viennent frapper les fibres extérieures, ne sont pas réfléchies dans la direction d'incidence, mais sont dirigées vers toutes les directions possibles du fait que des fibres de bois ne sont généralement pas parallèles à; la surface des plaques, A l'intérieur des plaques, les ondes sonores viennent frapper les fibres entremélées et qui sont inclinées suivant différents angles. Elles

  
 <EMI ID=4.1> 

  
tions et viennent toucher d'autres fibres de bois qui

  
les renvoient vers d'autres directions.à l'intérieur de  la plaque. Comme chaque réflexion réduit l'energie des ondes, ces réflexions répétées conduisent à la suppres&#65533;  sion complète du son.

  
Pour l'absorption de l'écho, il est essentiel

  
qu'une partie aussi faible que possible de la surface-

  
soit unie: Dans ce sens le revêtement selon l'inven- 

  
tion est notablement supérieur à celui obtenu à l'aide

  
de matières fibreuses qui ne sont pas cimentées du fait

  
que les parois qui doivent soutenir ces dernières ont

  
un. effet aplanisseur. 

  
Il est en outre nécessaire que la structure de

  
la surface soit irrégulière et à larges pores, c'est-à- ' dire macroscopique. Les dimensions des saillies et des creux doivent se trouver dans la zone des ondes sonores.

  
 <EMI ID=5.1> 

  
 <EMI ID=6.1> 

  
 <EMI ID=7.1> 

  
uni ou lisse pour des ondes lumineuses malgré que de telles surfaces polies montrent, à l'examen microscopique,' une forte rugosité ou inégalité. Pour cette raison les

  
 <EMI ID=8.1> 

  
nues &#65533; l'aide des fibres fortement tassées de la canne à sucre, n'ont aucun effet absorbant pour les sons. Ce n'est

  
 <EMI ID=9.1> 

  
fisamment grands, qu'on crée une inégalité de surface



  "Improvements to partition coverings

  
absorbing sound ".

  
We have already used, as an absorbent coating

  
sounds, fibrous materials, such as wool

  
asbestos, wood wool or the like, and

  
this as a filling for hollow bricks with wall

  
perforated exterior or by inserting them into an inter-

  
valle left between the partition and the support plates

  
perforated made integral with said partition. In

  
both cases, it is necessary to provide means

  
auxiliaries for keeping the fibrous materials in

  
square.

  
In accordance with the present invention,

  
 <EMI ID = 1.1>

  
cemented or masticated fibrous materials which

  
do not receive any coating. Wood wool cemented with Sorel cement has given particularly beneficial results.

  
The cladding can be fabricated on site using a suitable formwork or it can also be made using sheets, manufactured at the factory,

  
 <EMI ID = 2.1>

  
form a continuous surface. The coating obtained according to the invention can be established in a much more economical manner than the known coatings; it can be more easily put in place and is, moreover, more efficient because the support means, which influence sound absorption, do not exist.

  
In addition, the cemented fibrous materials con-

  
 <EMI ID = 3.1>

  
large pores whereas such materials, when they are not connected together, settle after a certain time.

  
The strong sound damping effect, obtained by means of an uncoated coating consisting of cemented wood wool, results from the fact that the material has large pores in which sound waves can penetrate. The few sound waves, which strike the outer fibers, are not reflected in the direction of incidence, but are directed in all possible directions because wood fibers are generally not parallel to; the surface of the plates, Inside the plates, the sound waves strike the intermingled fibers which are inclined at different angles. They

  
 <EMI ID = 4.1>

  
and touch other wood fibers which

  
send them back to other directions. inside the plate. As each reflection reduces the energy of the waves, these repeated reflections lead to the suppres &#65533; complete zion of sound.

  
For echo absorption it is essential

  
that as small a part of the surface as possible

  
is plain: In this sense the coating according to the invention

  
tion is significantly higher than that obtained using

  
of fibrous material which is not cemented due to

  
that the walls which must support the latter have

  
a. flattening effect.

  
It is further necessary that the structure of

  
the surface is irregular and large-pored, ie macroscopic. The dimensions of the protrusions and depressions must lie in the area of the sound waves.

  
 <EMI ID = 5.1>

  
 <EMI ID = 6.1>

  
 <EMI ID = 7.1>

  
plain or smooth for light waves despite such polished surfaces showing, on microscopic examination, 'a strong roughness or unevenness. For this reason the

  
 <EMI ID = 8.1>

  
naked &#65533; using the tightly packed fibers of sugar cane, have no sound absorbing effect. It's not

  
 <EMI ID = 9.1>

  
large enough, that we create an inequality of surface

Claims

necessary for sound absorption. However, it is obvious that plates thus perforated, because of their regular structure, are much less effective than the plates obtained according to the invention.

To increase the inequality of the surface we give the; section of wood fiber, which is generally rectangular 'and has dimensions of 6 x 0.4 mm, a shape which more closely resembles the square shape by having <EMI ID = 10.1>

a similar shape for the section, it becomes impossible to lay the wood fibers flat during molding and they retain the twisted shape they received

The coating can be covered with a paint plaster to increase the decorative effect. As particularly suitable, there may be mentioned the bronze colors, because they reduce the. roughness of the fibers which are on the surface and thus make the deposition of dust more difficult. At the moment, as visible in fig. 1 of the attached drawing, applied

hanging 2, the joints between the plates disappear.

Along with these bands, sleepers 3 can be used which are twice as wide as said bands and subdivide the surface of the plates so as to give the impression of a continuous ordinary coating. By using different colors for the panels, patterns pleasing to the eye can be obtained.

Another way to give the coating an aesthetic appearance is to lay the plates not

<EMI ID = 13.1> like the wooden floor boards by arranging them so that they make an angle between them. The narrower edges butt against the wider edges of the other plates. The two lateral edges of the plates have, as a result of the mode of constitution of these by section.

J.

which helps to improve the absorbent effect,

can bevel the edges of the outer face of the plate, Figs.3 and 4 show respectively such a plate in elevation and in section. The main reason

CLAIMS.

1) Coating for sound absorbing partitions,

example of lightly pressed wood wool and treated with Sorel cement, materials which are not provided

coated by uncoated sheets consisting of wood or similar fibrous material cemented.

characterized in that the transverse dimensions' of. the. Wood wool or the like fibers are chosen in the proportions of 1: 1 to 4: 1 to increase their stiffness in a transverse direction and thus to prevent their flat arrangement during molding.

<EMI ID = 22.1> characterized in that the edges of the outer face of the plates are bevelled.,