Claims
- 1. An apparatus for the dry production of non-woven uniform webs comprising: first means for the formation of an initial aerated, homogeneous and isotropic layer of particles with more than 95% empty space, and second means for reducing the thickness of the layer while maintaining the homogeneous and isotropic nature thereof, said first means including a conveyor belt with a specific direction of movement, a particle discharge unit, and means below the discharge unit for distributing the particles from the discharge unit onto the conveyor belt at a vertical speed less than free fall speed and in a manner achieving isotropic orientation of the particles, said means for distributing the particles comprising a cowl having an upper end directly communicated with the particle discharge unit, and an enlarged lower end overlying the conveyor belt along a length of the conveyor belt, said cowl including a pair of walls spaced along the conveyor belt in the direction of movement thereof, said walls extending transversely of the conveyor and flaring outward relative to each other toward the lower end of the cowl, the inclination of the walls in relation to the horizontal being between 60.degree. and 90.degree., said means for distributing the particles further including turbulence inducing means for providing zones of local turbulence within said cowl.
- 2. An apparatus according to claim 1, wherein said turbulence inducing means includes upwardly directed air injection means.
- 3. An apparatus according to claim 2, wherein each of said walls is provided with means for removing air from said cowl above said air injection means.
- 4. An apparatus according to claim 1, wherein each of said walls is provided with means for removing air from said cowl.
- 5. An apparatus according to claim 1, wherein the height of the cowl is between 1 and 10 m.
- 6. An apparatus according to claim 1, wherein the height of the cowl is between 4 and 6 m.
- 7. An apparatus according to claim 1, wherein said second means for reducing the thickness the layer while maintaining the homogeneous and isotropic nature thereof includes peak removal means downstream of the cowl, in the direction of movement of the conveyor belt, said peak removal means comprising a rotatable peak removal device overlying the conveyor belt and means for blowing air oriented toward the peak removable device so as to insure the cleaning of the peak removal device.
- 8. An apparatus according to claim 7, including suction means downstream of said cowl and oriented below the conveyor belt for a downward drawing of air through the conveyor belt and an extraction of air from the overlying layer of particles, mechanical pressure applying means overlying the conveyor in a general alignment over the downstream portion of the suction means for subjection of the layer of particles to a combined downward suction of air therefrom and a mechanical pressure thereon, subsequent to the initial subjecting of the layer to suction alone.
- 9. An apparatus according to claim 8, including a layer calendering means downstream of the suction means and oriented for engagement with the layer of particles.
- 10. An apparatus according to claim 1, wherein the means for distributing the particles onto the conveyor belt at a vertical speed less than free fall comprises only means acting against the free fall of the particles, said discharge unit comprising at least one cyclone separator fed by a mixture of air and particles which effects the separation of the air from the particles to release particles with an initial speed of fall which is substantially zero.
- 11. An apparatus according to claim 10, wherein the means for distributing the particles effects a distribution thereof at a superficial volume rate of less than 2,000cm.sup.3 /m.sup.2 /min.
- 12. An apparatus for the dry production of non-woven uniform webs comprising means for the formation of an initial aerated, homogeneous and isotropic layer of particles with more than 95% empty space, said means including a horizontally travelling conveyor belt with a specific direction of movement, a particle discharge unit for releasing particles for free fall, and means below the discharge unit for distributing the particles from the discharge unit onto the conveyor belt and subjecting the particles to flow of air acting solely against, and without enhancing, the free fall of the particles onto the conveyor belt; and means for reducing the thickness of the layer subsequent to the initial formation thereof on the belt and while maintaining the homogeneous and isotropic nature thereof, said means for reducing the thickness of the layer including suction means underlying said horizontally travelling belt solely downstream of the means for distributing the particles from the discharge unit onto the conveyor belt, said suction means acting through said belt for a downward extraction of air from the formed layer, and mechanical pressure means overlying said horizontally travelling belt for engagement with said layer, said pressure means being aligned over a downstream portion of the suction means for a combined extraction of air and mechanical pressure on said layer subsequent to an initial downward extraction of air from said layer, and additional mechanical pressure means positioned for engagement with said layer downstream of the first mentioned mechanical pressure means.
Priority Claims (1)
Number |
Date |
Country |
Kind |
75 08312 |
Mar 1975 |
FRX |
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Parent Case Info
This is a division of application Ser. No. 653,665, filed Jan. 30, 1976.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
349,465 |
Nov 1960 |
CHX |
Divisions (1)
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Number |
Date |
Country |
Parent |
653665 |
Jan 1976 |
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