Headbox for Paper Machine

Abstract

An object of the present invention is to provide a headbox for a paper machine in which correction of the fiber orientation of paper is possible over the entire width of the C/D direction, regardless of the slice width, and in which the fiber orientation in the direction of paper thickness can be corrected over the entire thickness of the paper. A headbox (1) for a paper machine according to claim (1) of the present invention discharges paper raw material onto a wire as a raw material jet gj from a slice (5) which is supplied with the paper raw material, and comprises orientation correcting means (h3) for correcting the pulp fiber orientation by supplying paper raw material, which is extracted from a taper header (2) in which paper raw material for a main flow is stored, or from a correction-only taper header (2s) in which paper raw material for correcting the pulp fiber orientation is stored, as a correction flow to a single location in a central portion of the slice (5) via at least one flow control valve (b3).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1( a) and (b) are a schematic top view of a headbox for a non-concentration controlling type paper machine of a first embodiment according to the present invention, and a schematic view seen from the direction of an arrow C, showing the interior of the headbox in FIG. 1(a).

FIGS. 2( a) and (b) are a schematic top view of a headbox for a non-concentration controlling type paper machine of a second embodiment according to the present invention, and a schematic view seen from the direction of an arrow D, showing the interior of the headbox in FIG. 2(a).

FIGS. 3( a) and (b) are a schematic top view of a headbox for a non-concentration controlling type paper machine of a modified example of the second embodiment according to the present invention, and a schematic view seen from the direction of an arrow E, showing the interior of the headbox in FIG. 3(a).

FIGS. 4( a) and (b) are a schematic top view of a headbox for a concentration controlling type paper machine of a third embodiment according to the present invention, and a schematic view seen from the direction of an arrow F, showing the interior of the headbox in FIG. 4(a).

FIGS. 5( a) and (b) are a schematic top view of a headbox for a concentration controlling type paper machine of a modified example of the third embodiment according to the present invention, and a schematic view seen from the direction of an arrow G, showing the interior of the headbox in FIG. 5(a).

FIGS. 6( a) and (b) are a schematic top view of a headbox for a concentration controlling type paper machine of a fourth embodiment according to the present invention, and a schematic view seen from the direction of an arrow H, showing the interior of the headbox in FIG. 6(a).

FIGS. 7( a) and (b) are a schematic top view of a headbox for a concentration controlling type paper machine of a fifth embodiment according to the present invention, and a schematic view seen from the direction of an arrow I, showing the interior of the headbox in FIG. 7(a).

FIGS. 8( a) and (b) are a schematic top view of a headbox for a concentration controlling type paper machine of a sixth embodiment according to the present invention, and a schematic view seen from the direction of an arrow J, showing the interior of the headbox in FIG. 8(a).

FIGS. 9( a) and (b) are a view showing an example of the disposal of pulp fibers ps in relation to the flow direction of a raw material jet of the paper manufactured by the paper machine, and an enlarged sectional view showing in detail the thickness direction of the paper.

FIGS. 10( a) and (b) are a schematic top view of a headbox for a conventional non-concentration controlling type paper machine, and a schematic view seen from the direction of an arrow A, showing the interior of the headbox in FIG. 10(a).

FIGS. 11( a) and (b) are a schematic top view of a headbox for a conventional concentration controlling type paper machine, and a schematic view seen from the direction of an arrow B, showing the interior of the headbox in FIG. 11(a).

DESCRIPTION OF REFERENCE SYMBOLS

1, 20, 21, 30, 31, 41, 51, 61 headbox

2, 2′, 32a, 32a′ taper header

5, 5′, 35, 35′ slice

2 s, 2 s′, 32a1, 32b1, 32a1′, 32b1′ correction-only taper header

b1, b2, b3, b21, b22, b23, b31, b32, b33, b41, b42, b43, b5, b6, kb5, kb6, b7, b81, b82, b83, b91, b92, b93, b101, b102, b103, b111, b112, b113, kb101, kb102, kb103, kb111, kb112, kb113, b121, b122, b123, kb121, kb122, kb123 flow control valve

gj raw material jet

h1, h2, h21, h22, h23, h31, h32, h33, h5, h6, h81, h82, h83, h91, h92, h93, h3, h41, h42, h43, h7, h121, h122, h123 correction flow pipe (the orientation correcting means of claim 1)

h101, h102, h103, h111, h112, h113 correction flow pipe (the orientation correcting means of claim 3)

h21, h22, h23, h31, h32, h33, h41, h42, h43, h81, h82, h83, h91, h92, h93, h101, h102, h103, h111, h112, h113, h121, h122, h123 correction flow pipe (paper thickness direction correcting means)

r1, r2, r3, r21, r22, r23, r31, r32, r33, r41, r42, r43, r5, r6, r7, r81, r82, r83, r91, r92, r93, r101, r102, r103, r111, r112, r113, r121, r122, r123 flowmeter

Claims

1. A headbox for a paper machine which discharges paper raw material onto a wire as a raw material jet from a slice which is supplied with the paper raw material, comprising orientation correcting means for correcting the pulp fiber orientation by supplying the paper raw material, which is extracted from a taper header in which paper raw material for a main flow is stored or from a correction-only taper header in which paper raw material for correcting the pulp fiber orientation is stored, as a correction flow to a single location in a central portion of the slice via at least one flow control valve.

2. A headbox for a paper machine which discharges paper raw material onto a wire as a raw material jet from a slice which is supplied with the paper raw material, comprising orientation correcting means for correcting the pulp fiber orientation by supplying the paper raw material, which is extracted from a taper header in which paper raw material for a main flow is stored or from a correction-only taper header in which paper raw material for correcting the pulp fiber orientation is stored, as a correction flow to a plurality of locations on the slice, other than the two end portions thereof, via at least one flow control valve.

3. The headbox for a paper machine according to claim 1, further comprising orientation correcting means for correcting the pulp fiber orientation by supplying the paper raw material extracted from said taper header or said correction-only taper header as a correction flow to the two end portions of the slice via the flow control valve.

4. The headbox for a concentration controlling type paper machine according to claim 1, wherein at least one of said orientation correcting means comprises a plurality of paper thickness direction correcting means overlapping in the direction of paper thickness for correcting the pulp fiber orientation in the paper thickness for correcting the pulp fiber orientation in the paper thickness direction by supplying a correction flow via respective flow control valves.

5. The headbox for a paper machine according to claim 1, wherein said orientation correcting means use concentration-controlled paper raw material when said correction flow flows to a location which is to become an end product in the direction of paper width.

6. The headbox for a paper machine according to claim 1, wherein said orientation correcting means use concentration-controlled paper raw material.

7. The headbox for a paper machine according to claim 1, wherein said orientation correcting means comprise a flowmeter on a pipe provided with said flow control valve, said headbox further comprising:a fiber orientation sensor for measuring the pulp fiber orientation of the manufactured paper; andcontrol means for controlling said flow control valve on the basis of pulp fiber orientation data for the manufactured paper obtained by said fiber orientation sensor, and data from said flowmeter.