| DE2715747A1 | 1977-10-20 | |||
| GB1092052A | 1967-11-22 |
| 1. | Method for distributing fibers (1) in a layer, c h a r a c t e r i z e d in that the fiber layer (1) is exposed to a lowfrequency airborne sound field. |
| 2. | Method according to claim 1, c h a r a c ¬ t e r i z e d in that the sound field is emitted from a resonator (3). |
| 3. | Method according to claim 1 or 2, c h a r • a c t e r i z e d in that the fiber layer (1) is exposed to the sound field from below on an air per¬ meable support (2). |
| 4. | Method according to any of claims 1 to 3, c h a r a c t e r i z e d in that the propagation of the sound field is controlled to actuate different portions of the fiber layer (1) with sound fields of different strengths. |
| 5. | Method according to any of claims 1 to 4, c h a r a c t e r i z e d in that the fiber layer (1) is sprayed with an adhesive when being exposed to the sound field. |
The invention relates to a method for distributing fibers in a layer, the fibers possibly being filted at the same time.
- According to the invention, the distribution of the fibers is achieved by exposing the layer to a low- -frequency airborne sound field.
In order to illustrate the invention this will be described in more detail below, reference being made to the accompanying drawing, which shows a diagrammatic vertical cross-sectional view of an apparatus for practising the method. *
The fibers 1 are laid down onto an air permeable support 2 which is arranged in front of a sound emitter 4 located in a resonator 3. In the present case the resonator 3 comprises a Hel holtz resonator and the sound emitter 4 comprises an electric loud speaker of the diaphragm type, which is mounted in a wall of the resonator. The layer of fibers is exposed to 1 ow-
-frequency airborne sound from the sound emitter 4, and by the exposure to sound the fiber layer is fluidized and spreads uniformly over the support as indicated by a dash line 5. If the fibers 1 are of such character that they can be entangled with each other, or if the fibers during the fluidization are sprayed with an adhesive, there will be obtained in this way a bound fiber mat of uniform thickness. The exposure of the fiber layer to sound can also take place from the upper side of the layer.
If varying thickness of the layer is desired so that a definite profile is imparted to the layer as indicated by a dash and dot line 6, an accumulation of the fibers at one or more places as desired can be
obtained by controlling the propagation of the sound field such that different portions of the fiber layer are exposed to sound fields of different strengths.