Method and an apparatus for distributing a disintegrated material onto a layer forming surface

Abstract

A method and an apparatus for distributing loose fibers or particles onto a moving web in an even layer thereon preparatory to production of a non-woven sheet of the fiber or particle material. The material is filled into a container having a generally V-shaped screen bottom extending crosswise over the moving web, and whipping members are rotated in the bottom space so as to whip the material adjacent the interior surface of the screen by a whipping movement causing the fibers or particles to be slung against the screen and the material to move in a flow lengthwise along the bottom surfaces, whereby when suction is applied to the outside of the screen bottom through the web the fibers or particles will get dispensed through the screen and deposited on the web. The combined shipping and slinging of the material contributes to a high capacity of the distribution.

Description

This is a continuation of application Ser. No. 717,384, filed Aug. 24, 1976, now abandoned.

The present invention relates to a method of distributing loose fibres or particles onto a carrier surface constituted by a carrier web, by filling the fibre or particle material into a container having a screen wall portion located adjacent one side of said carrier web, agitating the material violently and creating an air flow through the material and through the said screen and web by sucking air from the other side of the web so as to cause the fibres or particles to gradually penetrate the screen and get deposited in a layer on the moving carrier web.

A method of this type and an apparatus for carrying out the method is disclosed in the British patent specification No. 1,207,556 (corresponding to U.S. Patent No. 3,581,706). continuous operation during a longer period of time parts of the screen may be clogged up or choked by fibres or foreign matters, whereby a thinner zone of the sheet may be produced. This can be counteracted by means of the individually operable gate sections and may be controlled by automatic means. It will be appreciated that this method of controlling the thickness of a sheet material formed by suction not only is suitable for correcting the uniformity of the cross section of the sheet, but also can be used advantageously as a control means for the thickness of the sheet in general. This thickness control means may further be used in connections other than that of the present invention, i.e. where a submatters of a material is deposited on a forming surface by means of suction.

It should be noted that the slanting screen walls should preferably be provided with the perforations showing free openings as seen in the direction of the centrifugal forces of the rotor members, thus facilitating the penetration of the fibres through the screen. A minor disadvantage of this would be that some fibres were directed directly towards the inner surface of the exterior wall plate 50, so as to build up upon these and give rise to the risk of clumps of articles falling down upon the the sheet of fibres, but this risk is counteracted by means of the scavenging current through the channel 52. Another way of overcoming this problem could be the substituting of the wall plate 50 by a horizontal roller covering with part of its surface the triangular space between the screen 16 and the web. In this way the fibres deposited upon the roller surface can be continuosly removed and the scavenging channel 52 and the sluice 56 may be omitted.

Claims

1. Apparatus for depositing and distributing loose fibres or particles onto a surface of a moving carrier web comprising:

(a) a housing having inlet and outlet ends;

(b) a moving carrier web having a surface positioned adjacent the outlet end of said housing;

(c) screen means within said housing between said inlet and outlet ends, at least part of said screen means being arranged so as to extend in a manner which is transverse and non-parallel with respect to the surface of the moving carrier web;

(d) agitator means within said housing for creating a flow of said particles or fibres about an axis extending between said inlet and outlet ends, and for directing said particles or fibres outwardly against and through said part of said said screen means; and

(e) means for directing particles or fibres passing through said screen means to said moving carrier web whereby said particles or fibres are deposited in a layer upon said moving carrier web.

2. Apparatus according to claim 1, wherein said agitator means includes a plurality of agitating members, said agitating members being positioned in spaced areas along the screen means for causing said material to move in a flow, relatively slowly, with respect to the speed of the agitating members, from one area to an adjacent area.

3. An apparatus according to claim 2, in which the housing is elongated crosswise of said moving carrier web and is provided with one row of said agitating members, the part of the screen means which extend transversely and non-parallel with respect to the moving carrier web being located at both sides of said row.

4. Apparatus according to claim 2, characterized in that the whipping is effected by whip members which are rotated in a plane of rotation which intersects said part of the screen means which is transverse and non-parallel to the carrier web.

5. An apparatus according to claim 4, wherein the agitating members are mounted in a stationary row along the screen means and are provided with thin whip elements, the outermost portions of which pass closely along portions of the transversely and non-parallel extending part of said screen means and move in a plane of rotation which is non-parallel to the respective screen portions, all whip members being rotated in a uniform direction of rotation.

6. An apparatus according to claim 5, in which the whip elements project radially from shafts of the agitating members and in which at least some of the whip members of two adjacent agitators are axially offset from each other and mounted so as to rotate in overlapping circular paths.

7. An apparatus according to claim 5, in which the whip elements are constituted by radially projecting rods of flat cross section.

8. An apparatus according to claim 7, in which the rods have opposed surfaces which taper towards each other at least adjacent leading edges of the rods.

9. Apparatus according to claim 1, characterized in that said agitating members are rotary whip members which are rotated in a plane of rotation which intersects said part of the screen means which is transverse and non-parallel to the carrier web.

10. Apparatus according to claim 9, wherein said agitating members have plural whipping elements which whip said fibres or particles, as they rotate about a respective axis, in a manner causing disturbance of the fibres or particles without to any substantial degree causing the material to move with the whipping elements about their respective axis of rotation.

11. An apparatus according to claim 1, wherein said screen means is provided with a bottom having a lower flat portion located above and parallel with the moving carrier web and outer inclined side portions, and wherein the agitator means includes whip members arranged so as to form a correspondingly frusto-conical pattern.

12. An apparatus according to claim 1, in which the housing includes wall portions arranged so as to confine a space between said part of the screen means and the moving carrier web, said space communicating with air intake means for external air.

13. Apparatus according to claim 1, wherein said agitator means comprises a plurality of whip members spaced radially and axially along a rotatable shaft, said whip members being positioned within said container so as to enable all of said whip members to pass in close proximity to said screen.

14. Apparatus according to claim 1, wherein said means for directing comprises a wall member of said housing arranged about said screen means so as to form a space communicating an air intake with said carrier web externally of said screen.

15. Apparatus according to claim 1, wherein said means for directing comprises suction means for drawing the fibre or particle material through said screen means.

16. Apparatus according to claim 15, wherein said moving carrier web is foraminous and said suction means includes a suction box disposed on a side of said moving carrier web which is opposite from the surface adjacent said housing outlet.

17. A method for depositing and distributing loose fibre or particle material onto a surface of a moving carrier web comprising the steps of:

(a) feeding the loose fibre or particle material into a housing having inlet and outlet ends, the outlet end being positioned adjacent a surface of a moving carrier web;

(b) agitating said material within said housing by creating a flow of said material about an axis extending between the inlet and outlet ends of the housing and directing said material outwardly against a screen means which is located in said housing and at least in part extends in a manner which is transverse and non-parallel to said surface of the moving carrier web and through said part of said said screen means; and

(c) directing material passing through the screen means to said moveable carrier web so that said material is deposited in a layer upon the surface of the moving carrier web.

18. A method according to claim 17, wherein the step of agitating is performed by a plurality of rotary agitating members positioned along spaced areas of the screen means and wherein the material is caused to move in a flow, relatively slowly in comparison to the speed of the agitating members from one area to an adjacent area.

19. A method according to claim 18, wherein the step of agitating is performed by causing a disturbance of the material without to any substantial degree causing the material to move with the rotary agitating members about their respective axis of rotation.

20. A method according to claim 18, wherein the material is directed through the screen means at least in part by suction.

21. A method according to claim 20, wherein the step of directing the fibre of particle material through said screen means by suction is performed by a suction box disposed beneath said carrier web drawing air through said housing, screen means, and carrier web.

22. Apparatus for distributing and depositing loose fibers or particles onto a surface of a moving carrier web comprising:

(a) a foraminous moving carrier web;

(b) a distributor housing having an outlet positioned above said carrier web;

(c) screen means within said housing for screening a flow of said fibers or particles therethrough prior to their being discharged from said outlet onto said carrier web;

(d) flow producing means within said housing, upstream of said screen means, for creating a flow of fibers or particles circulating within said housing and as a whole traveling transversely across said screen means and a line of movement of the moving carrier web and for creating said flow of fibers or particles through said screen means outwardly therefrom; and

(e) suction means below said carrier web for drawing said fibers or particles from said outlet onto said carrier web. 23. Apparatus according to claim 22, wherein said flow producing means is an agitator means. 24. Apparatus according to claim 23, wherein said agitator means comprises at least one shaft mounted for rotation about a substantially horizontal axis and a plurality of impellors extending therefrom, some of said impellors being shaped to create a flow longitudinally relative to said shaft for producing said flow transversely across said screen means. 25. Apparatus according to claim 22 or 24, wherein said flow producing means comprises a plurality of agitator means, a first of said agitator means producing said flow transversely across said screen means in a first direction and a second of said agitator means producing said flow transversely across said screen means in an opposite direction, and together said agitator means acting to cause said flow transversely across said screen means to circulate in a path around in said housing. 26. Method for distributing and depositing loose fibers or particles comprising the steps of:

(a) feeding loose fibers or particles into a distributor housing having an outlet positioned above a foraminous moving carrier web;

(b) creating a flow of said particles or fibers circulating within said housing and as a whole traveling transversely across both a screen means positioned for screening a flow of said particles and fibers outwardly therethrough and a line of movement of said carrier web, and applying outwardly directed forces to said transverse flow for creating said flow through said screen means; and

(c) drawing said fibers or particles, flowing outwardly through said screen means, onto said carrier web so as to be deposited in a layer thereon. 27. Method according to claim 26, wherein said creating steps are performed by agitator means within said housing upstream of said screen means. 28. Method according to claim 27, wherein said agitator means is caused to rotate about a substantially horizontal

axis. 29. Apparatus for distributing and depositing loose fibers or particles onto a surface of a moving carrier web comprising:

(a) a foraminous moving carrier web;

(b) a distributor housing having an outlet positioned above said carrier web;

(c) screen means within said housing for screening a flow of fibers or particles therethrough prior to their being discharged from said outlet onto said carrier web said screen means being elongated in a direction substantially parallel to with the surface of the moving carrier web;

(d) flow producing means within said housing, upstream of said screen means, for creating a flow of fibers or particles circulating within said housing and as a whole traveling transversely across said screen means in said direction of elongation substantially parallel to the surface of the moving carrier web and for creating said flow of fibers or particles through said screen means outwardly therefrom; and

(e) suction means below said carrier web for drawing said fibers or particles from said outlet onto said carrier web. 30. Apparatus according to claim 29, wherein said flow producing means is an agitator means. 31. Apparatus according to claim 30, wherein said agitator means comprises at least one shaft mounted for rotation about a substantially horizontal axis and a plurality of impellors extending therefrom, some of said impellors being shaped to create a flow longitudinally relative to said shaft for producing said flow transversely across said screen means in said direction of

elongation. 32. Apparatus according to claim 31, wherein said shaft extends in said direction of elongation and each of said impellors rotates in a plane that intersects said screen means. 33. Apparatus according to claim 29 or 30, wherein said flow producing means comprises a plurality of agitator means, a first of said agitator means producing said flow transversely across said screen means in a fist direction of elongation and a second of said agitator means producing said flow transversely across said screen means in an opposite direction of elongation and together said agitator means acting to cause said flow transversely across said screen means to circulate in a path around in said housing. 34. Apparatus according to claim 29, wherein said housing is provided with outer wall portions disposed on an exterior side of portions of said screen means that extend in a generally non-parallel manner with respect to the surface of the moving carrier web, said outer wall and screen means portions defining an air duct having an upper air intake end and a lower end communicating with said housing outlet, whereby both said outward flow of fibers or particles and a scavenging air flow pass through said air duct. 35. Method for distributing and depositing loose fibers or particles onto a surface of a moving carrier web comprising the steps of:

(a) feeding loose fibers or particles into a distributor housing having an outlet positioned above a foraminous moving carrier web;

(b) creating a flow of said particles or fibers circulating within said housing and as a whole traveling across a screen means that is elongated in a direction substantially parallel the surface of the moving carrier web and positioned for screening a flow of said particles and fibers outwardly therethrough in said direction of elongation parallel to the surface of said carrier web, and applying outwardly directed forces to said transverse flow for creating said flow through said screen means; and

(c) drawing said fibers or particles, flowing outwardly through said screen means, onto said carrier web so as to be deposited in a layer thereon. 36. Method according to claim 35, wherein said creating steps are performed by agitator means within said housing upstream of said screen means. 37. Method according to claim 36, wherein said agitator means is caused to rotate about a substantially horizontal axis. 38. Method according to claim 37, wherein said agitator means comprises a plurality of rotary shafts each having a plurality of impellors, some of said impellors on each shaft being shaped to create a flow longitudinally of said shaft, said agitator means being operated to cause said flow transversely across the screen means to circulate in a path around in said housing. 39. Method according to claim 28, wherein said agitator means comprises a plurality of rotary shafts each having a plurality of impellors, some of said impellors on each shaft being shaped to create a flow longitudinally of said shaft, said agitator means being operated to cause said flow transversely across the screen means to circulate in a path around in said

housing. 40. An apparatus for distributing loose fibers or particles onto a moved foraminous sheet, comprising:

A distributor container located overhead said foraminous sheet and having an inlet for fiber or particle material to be distributed and a perforated outlet wall portion, through which the material is dispensable to a space outside an exterior side of the outlet wall portion,

means for creating a flow of air through the foraminous sheet, by suction from beneath the sheet, in an area generally underneath the said space outside of the outlet wall portion to thereby cause the material as dispensed through said outlet wall portion to be carried towards and be deposited on the foraminous sheet,

said perforated outlet wall portion being elongate generally in a first direction, which is substantially parallel with the surface of the foraminous sheet;

agitator means located inside said distributor container for agitating the material and keeping it air fluidized therein,

means for creating a unidirectional, primary flow of the air fluidized material along the interior side of the outlet wall portion substantially in said first direction thereof, from an upstream end to a downstream end of the wall,

means for continually guiding said flow of air fluidized material back from said downstream end to said upstream end of the outlet wall portion along a path spaced from said primary flow for recirculation of the material flow,

said inlet of the distributor container communicating with the path of said material flow to enable supply of material thereto; and

deviator means, forming part of said agitator means, located inside said container operable to impart to the said primary material flow or selected portions thereof a velocity component directed outwardly through said outlet wall, thereby to promote material dispensing through said outlet wall. 41. An apparatus according to claim 40, in which said deviator means comprise power driven impeller members located in one or more rows extending along the outlet wall portion in said first direction thereof, each of said impeller members rotating in a plane intersecting the outlet wall portion.