Patent EA-000255-B1 (EA)
Title: Apparatus for papermaking
Inventor: NEUN JOHN A
IPC: D21F1/40
Filed: 1996-08-23
Abstract: 1. A paper-making apparatus comprising a forming fabric for transporting paper stock, a portion of said forming fabric passing over a first liquid-filled cavity bounded on a lower surface by a flexible non-rigid membrane, and further including first means for exciting said first liquid-filled cavity via said membrane to disperse the paper stock. 2. A papermaking apparatus of Claim 1wherein said lower surface of said cavity is made as said flexible lower membrane. 3. The papermaking apparatus of Claim 1, wherein said lower surface of said cavity is made as a synthetic fiber. 4. The papermaking apparatus of Claim 1, wherein first means for exciting said first liquid-filled cavity comprises means for periodically exciting said lower surface. 5. The papermaking apparatus of Claim 4 wherein said means for periodically exciting said lower surface is oriented directly below said lower surface. 6. The papermaking apparatus of Claim 5 wherein said means for periodically exciting includes at least one roll journaled for rotation, said roll including protrusions about a circumference thereof. 7. The papermaking apparatus of Claim 6 wherein said at least one roll is journaled for rotation about a horizontal axis which is substantially perpendicular to a direction of travel of said forming fabric. 8. The papermaking apparatus of Claim 7 wherein said protrusions are spaced regularly about a circumference of said at least one roll. 9. The papermaking apparatus of Claim 6 wherein a horizontal position of a rotational axis of said roll is adjustable. 10. The papermaking apparatus of Claim 6 wherein a vertical position of a rotational axis of said roll is adjustable. 11. The papermaking apparatus of Claim 1 further including a second liquid-filled cavity over which said forming fabric passes and further including second means for exciting said second liquid-filled cavity to disperse the paper stock. 12. The papermaking apparatus of Claim 1 wherein a leading edge and a trailing edge of said first liquid-filled cavity include sinusoidal surfaces with a wavelength corresponding to an expected wavelength of oscillation of said membrane. 13. The papermaking apparatus of Claim 1 wherein a leading and a trailing edge of said first liquid-filled cavity are formed as surfaces of first and second foils. 14. The papermaking apparatus of Claim 1 further comprising a drainage means located beneath said first liquid-filled cavity such that water is drained from said paper stock subsequent to dispersal of the paper stock. 15. The papermaking apparatus of Claim 1 further including a second liquid-filled cavity over which said forming fabric passes and further including second means for exciting said second liquid-filled cavity to disperse the paper stock. 16. The papermaking apparatus of Claim 1 wherein a leading edge and a trailing edge of said first liquid-filled cavity include sinusoidal surfaces with a wavelength corresponding to an expected wavelength of oscillation of said membrane. 17. The papermaking apparatus of Claim 1 wherein said lower surface is inclined. 18. The papermaking apparatus of Claim 17, wherein a lower portion of said lower surface is downstream of a remaining portion of said lower portion, and said lower portion has an increased permeability from said remaining portion of said lower surface. 19. The papermaking apparatus of Claim 1 or 2 wherein said lower surface has a variable tension in a direction of travel of the forming fabric, variable across said direction. 20. A papermaking apparatus comprising a forming fabric for transporting paper stock, wherein a portion of said forming fabric passing over a flexible non-rigid membrane substantially free of clearance therefrom, and further including means for exciting said membrane to disperse the paper stock.