WO1997047804A1 - A multilayer headbox for a papermaking machine - Google Patents
A multilayer headbox for a papermaking machine Download PDFInfo
- Publication number
- WO1997047804A1 WO1997047804A1 PCT/SE1997/000921 SE9700921W WO9747804A1 WO 1997047804 A1 WO1997047804 A1 WO 1997047804A1 SE 9700921 W SE9700921 W SE 9700921W WO 9747804 A1 WO9747804 A1 WO 9747804A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- stock
- slice chamber
- upstream
- downstream
- stiffness
- Prior art date
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Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F9/00—Complete machines for making continuous webs of paper
- D21F9/003—Complete machines for making continuous webs of paper of the twin-wire type
- D21F9/006—Complete machines for making continuous webs of paper of the twin-wire type paper or board consisting of two or more layers
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/02—Head boxes of Fourdrinier machines
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/02—Head boxes of Fourdrinier machines
- D21F1/028—Details of the nozzle section
Definitions
- the present invention relates to a multilayer headbox for ejecting stock into a forming section of a papermaking machine for forming a fibrous web.
- stock is ejected from a slice chamber of a headbox into a forming section of a papermaking machine.
- the forming section may comprise a single forming fabric, a forming fabric in combination with a felt, or a pair of forming fabrics.
- water drains from the stock through a forming fabric so that a fibrous web is formed.
- layer purity should be understood as the degree to which the separate layers of the fibrous web are able to retain their respective composition, i. e. the degree to which mixing of the layers is avoided, while coverage should be understood as the degree to which each layer of the fibrous web has a uniform basis weight in the cross machine direction.
- the formed web has a poor coverage, this will have an adverse effect on the uniformity of the layer purity, which will render the operation of the papermaking machine more difficult since a uniform layer purity is required during subsequent phases of the papermaking process, e. g. during creping when the creping doctor will be adjusted in accordance with the surface properties of the fibrous web on the side adhering to the drying cylinder.
- a uniform layer purity is required during subsequent phases of the papermaking process, e. g. during creping when the creping doctor will be adjusted in accordance with the surface properties of the fibrous web on the side adhering to the drying cylinder.
- chemicals are added to the process in order to facilitate creping and the quantity and composition of the chemicals will depend on the surface qualities of the fibrous web.
- a web of non-uniform layer purity will render impossible an optimization of the papermaking process since adjustment of the creping doctor and the adding of chemicals will depend on the surface qualities of the fibrous web.
- the paper web should have a uniform strength across the web (i. e. in the cross machine direction) and a web having poor coverage will not be of uniform strength across the web. Therefore, there is a need for a multilayer headbox which is able to produce a multilayered web which has a good and uniform layer purity and a good coverage and which is also free of flocculations and has a uniform basis weight.
- the slice chamber has a top wall, a bottom wall and two side walls. The top and bottom walls converge in the straight main direction of flow of the stock through the slice chamber.
- the headbox further comprises a tube bank located upstream of the slice chamber in the direction of flow of the stock.
- the tube bank comprises a plurality of straight tubes.
- the tubes of the tube banks are arranged in vertically spaced tube bank sections such that each tube bank section in the tube bank is arranged to feed stock exclusively intended for one layer of the fibrous web to be formed.
- the tubes are arranged in vertically spaced rows, the rows extending in a cross machine direction.
- the tube bank can thus be described as comprising a plurality of straight tubes where the tubes are arranged in separate vertically spaced rows.
- Each tube has an upstream inlet end and a downstream outlet end from which stock is intended to pass into the inlet of the slice chamber such that the tube bank with its tubes forms a passage through which stock is intended to pass from the upstream inlet end of the tubes to the inlet of the slice chamber.
- the passage has a straight main direction of flow of the stock which coincides with the intended straight main direction of flow of the stock in the slice chamber so that all the way from the upstream inlet end of the tubes to the downstream outlet of the slice chamber, the stock will flow in one and the same straight main direction of flow.
- the headbox comprises at least one, but possibly two or three, machine-wide separator vane or vanes in the slice chamber.
- the separator vane subdivides the slice chamber such that a multilayered fibrous web may be formed.
- the separator vane (or vanes) has an upstream end and a downstream end and extend in the intended direction of flow of the stock and has a thickness in the vertical dimension.
- elongate ledges are provided that extend in a cross machine direction and connect the tube bank sections to each other.
- the upstream end of the separator vane (or of each separator vane) is fastened to one of the elongate ledges interposed between the vertically spaced tube bank sections in the tube bank
- the headbox further compnses, in the slice chamber, a plurality of machine-wide turbulence generating elements extending in the direction of flow of the stock
- Each turbulence generating element has an upstream end and a downstream end
- the upstream end of each turbulence generating element is interposed between the vertically spaced rows of tubes in a tube bank section and fixed between the rows
- the turbulence generating elements can be realized in the form of vanes with uneven, 1. e rough surface but the inventors have found that also vanes with a smooth surface will have a turbulence generating effect which is sufficient for the purpose of the invention
- the separator vanes are made to have a certain minimum stiffness in the cross machine direction for at least 7/10 of the length of the separator vane
- the stiffness of the separator vane is chosen to be on average at least 36 Nm and on at least 7/10 of the length of each separator vane, at least 7 Nm
- the separator vane (or vanes) should have an average stiffness which is at least 180 times higher than the stiffness of a 1 mm thick reference sheet or reference plate of a material having a modulus of elasticity of about 2100 MPa and that for at least 7/10 of the length of the vane (or vanes), the stiffness should be at least 35 times higher than for the reference sheet or reference plate
- the separator vane (or separator vanes) is a homogenous element made of glass fiber reinforced epoxy resm and is tapered all the way from its upstream end to its downstream end such that its thickness decreases continuously from its
- the separator vane (or vanes) is divided into an upstream section of constant thickness in the vertical dimension and a downstream section which is tapered such that its thickness decreases in the direction of flow of the stock
- the upstream section will have an upstream end which is the same as the upstream end of the separator vane and a downstream end to which the downstream section is fixed
- the downstream section will have an upstream end fixed to the upstream section of the separator vane and a downstream end which is the same as the downstream end of the separator vane
- the downstream section At the point where the upstream section is fixed to the downstream section, l e at the transition between the upstream section and the downstream section, there is a machine-wide step due to the fact that at the point where the upstream section is fixed to the downstream section, the downstream section has a thickness in the vertical dimension which is less than the thickness in the vertical dimension of the upstream section
- the upstream section might be of steel while the downstream section is preferably of glass fiber reinforced epoxy resin In that embodiment of the invention where
- the tapered downstream section has surface smoothness, or R a value, which is smaller than or equal to 0.4 ⁇ m.
- the thickness in the vertical dimension of the separator vane is less than 0.7 mm at the downstream end of the separator vane(s).
- the thickness in the vertical dimension should be about 0.5 mm.
- the thickness in the cross machine direction will of course be subject to a degree of variation. The inventors have found that the thickness at the downstream end should not vary more than 0.05 mm. When the thickness of the separator vane is chosen to be 0.5 mm, this will therefore result in a separator vane which, at its downstream end, has a thickness of 0.5 mm ⁇ 0.05 mm or 0.45 mm - 0.55 mm.
- Providing a separator vane, or separator vanes, having a surface smoothness which is, at least at a downstream end of the separator vane(s), smaller than 0.4 ⁇ m and having a thickness at its downstream end which is less than 0.7 mm contributes to the achievement of a good layer purity.
- layer purity it can be desirable to make the downstream end of the separator vane (or vanes) even thinner.
- the inventors have found that when the tip of a vane (the downstream end of the vane) is thinner than 0.5 mm, this makes the tip to weak and to likely to be broken by fatigue. Therefore, the inventors have found that a thickness of about 0.5 mm is preferable. In order to achieve that the layer purity will also be uniform, it is necessary that the formed web will also have a good coverage.
- the passage formed by the tube bank has the same main direction of flow of the stock as the slice chamber such that, all the way from the inlet of the tubes in the tube bank to the outlet of the slice chamber, the stock will be able to flow in one and the same main direction of flow.
- the slice chamber comprises turbulence generating elements.
- the separator vane (or vanes) are stiff in the cross machine direction.
- the thickness variation of the separator vane at its downstream end is no more than 0.05 mm.
- the inventors have found that when the headbox is formed as a straight flow headbox, i. e. when the stock flows in one and the same main direction of flow all the way from the inlet end of the tubes in the tube bank to the outlet of the slice chamber, this will have an advantageous effect on the coverage of the subsequently formed fibrous web and that this advantageous effect can be reinforced by providing turbulence generating elements in the slice chamber.
- Headboxes are known, e g. from U. S. Patent No. 4,941,950 (Sanford), where the stock is forced to change its direction of flow when it enters the slice chamber.
- the inventors of the present invention have recognized that such a design will have a disadvantageous effect on the coverage of the fibrous web and therefore, the inventors have designed the headbox of the present invention as a straight flow headbox such that the stock will not change its direction of flow as it enters the slice chamber.
- the separator vane, or separator vanes should be stiff in the cross machine direction.
- the inventors have found that one important cause for poor coverage is insufficient stiffness of the separator vane(s) in the cross machine direction. If the stiffness of the vane(s) in the cross machine direction is insufficient, this may cause flexing of the vane(s) such that, in the cross machine direction, the layers of the subsequently formed web will not have a uniform basis weight in the cross machine direction, i. e. the coverage will be poor. It is also desirable that the stiffness in the machine direction is high if a fibrous web which is uniform in the machine direction is to be obtained.
- the separator vanes employed in the present invention are of such a design that their thickness decreases towards the tip of the vanes, i. e. the thickness of a vane is less at the downstream end of the vane than at the upstream end of the vane. For this reason, the stiffness of the vane is not uniform. Instead, the stiffness of each vane decreases towards the downstream end of the vane. Therefore, the stiffness of a separator vane according to the present invention has to be calculated at different locations of the vane. Bending stiffness per meter length of a plate having a thickness h, a modulus of elasticity £, can be calculated according to the formula where 5 is stiffness and v is the Poisson ratio.
- the stiffness definition which is used in the context of this patent application.
- the Poisson ratio will normally be about 0.3 while for glass fiber reinforced resin, the Poisson ratio can be given as about 0.15.
- the stiffness is thus proportional to the product of the modulus of elasticity and the plate thickness.
- the invention has two different embodiments and in both embodiments, the material or materials used for the separator vane (or separator vanes) is isotropic in the sense that it has the same properties in both the machine direction and the cross machine direction (but not necessarily in the vertical dimension). Therefore, the stiffness of a separator vane, such as stiffness is defined in the context of this application, will be the same in both the machine direction and the cross machine direction.
- the thickness of the vane(s) must be small, preferably less than 0.7 mm and preferably about 0.5 mm, in order to obtain good layer purity.
- the inventors have found that it is sufficient that an upstream part of the separator vane(s) is of high stiffness and that if only the downstream end of the separator vane(s) is of a smaller stiffness, the relatively small stiffness of the downstream end of the separator vane(s) will not be able to cause any significant reduction of the good coverage of the fibrous web.
- the material or materials used for the separator vane is isotropic in the sense that it has the same properties in both the machine direction and the cross machine direction. For this reason, the stiffness at any given location along the length of a separator vane, as stiffness is defined in the context of this application, will be the same in both the machine direction and the cross machine direction.
- different separator vanes have been compared with a 1 mm thick reference sheet or reference plate of a polycarbonate material having a modulus of elasticity of about 2100 MPa.
- the Poisson ratio of the material used for the reference sheet was about 0.3.
- the tests carried out by the inventors showed that when the 1 mm thick reference sheet was used as a separator vane, the formed fibrous web had unsatisfactory coverage.
- the separator vane(s) has a stiffness in the cross machine direction which, for at least 7/10 (70%) of its length is at least 35 times greater than the stiffness of a 1 mm thick reference sheet of a polycarbonate material having a modulus of elasticity of about 2100 MPa.
- the vanes that where found to give satisfactory results with regard to the coverage of the formed fibrous web had an average stiffness which was at least 180 times higher than the stiffness of the reference sheet.
- average stiffness should here be understood as the stiffness value which is obtained by choosing at least 11 points on the separator vane evenly spaced from each other in the machine direction, adding the stiffness values of the different points and dividing the result by the number of points.
- the expression "for at least 7/10 of its length....35 times greater than a 1 mm thick reference sheet of a material having a modulus of elasticity of about 2100 MPa” should here be understood as meaning that the stiffness at the upstream end of the separator vane(s) is much higher than a 1 mm thick sheet (or plate) of a polycarbonate material having a modulus of elasticity of about 2100 MPa and that the stiffness gradually decreases towards the downstream end of the separator vane(s) but that for at least 7/10 (70%) of its length, the vane(s) has a stiffness at least 35 times greater than a 1 mm thick reference sheet (or reference plate) of a polycarbonate material having a modulus of elasticity of about 2100 MPa so that no more
- a separator vane (or separator vanes) which is tapered such that its thickness decreases linearly from its upstream end to its downstream end.
- the material used for this vane is an isotropic glass fiber reinforced epoxy resin having a modulus of elasticity of 25,000 MPa.
- this vane may have a thickness of 3.8 mm. The thickness gradually decreases towards the tip (the downstream end of the vane) where the thickness will be about 0.5 mm.
- the Poisson ratio is 0.15.
- the stiffness gradually decreases but for 7/10 (70%) of the length of the separator vane, the stiffness is at least 7 Nm and thus at least 35 times higher than the stiffness of the 1 mm thick reference sheet.
- the average stiffness in this case will be about 36 Nm and thus at least 180 times higher than the stiffness of the 1 mm thick reference sheet.
- the upstream section will have a substantially constant stiffness all the way from the upstream end of the vane(s) to the point where the downstream section of the separator vane(s) is fastened to the upstream section.
- the downstream section will then have a gradually decreasing stiffness.
- the upstream section of constant thickness may be of steel and have a modulus of elasticity of 203,000 MPa and a thickness of about 12 mm.
- the Poisson ratio (v) in this case is about 0.3.
- the length of the upstream steel section may be around 500 mm.
- the downstream section has a linearly decreasing thickness which goes from 3.8 mm at its upstream end to about 0.5 mm at its downstream end.
- the material chosen for the downstream section is glass fiber reinforced epoxy resin having a modulus of elasticity of 25000 MPa and the Poisson ratio (v) is about 0.3.
- the length of the downstream section may be around 330 mm, giving the separator vane a total length of 830 mm.
- the stiffness of the upstream end of the downstream section as stiffness is defined in the context of this patent application, can be calculated as being 117.2 Nm.
- FIG 1 is a cross sectional view of a headbox according to one embodiment of the present invention
- FIG. 2 is a cross sectional view similar to FIG 1 showing in greater detail parts of a headbox according to a second embodiment of the invention
- FIG 3 is a cross sectional view of a multilayered fibrous web having good layer punty and good coverage.
- FIG 4 is a cross sectional view of a multilayered fibrous web having a poor layer punty
- FIG. 5 is a cross sectional view of a multilayered web having good layer punty but poor coverage
- FIG 6 shows a comparative study of the stiffness of two different separator vanes compared with the stiffness of a 1 mm thick reference sheet of a matenal having a modulus of elasticity of about 2100 MPa
- FIG 7 is a cross sectional view showing a separator vane according to a preferred embodiment of the invention
- FIG 8 is a cross sectional view showing a separator vane according to a second embodiment of the invention.
- FIG 9 is a cross sectional view similar to FIG 1 showing in greater detail some parts of the slice chamber
- a headbox 1 is shown
- the headbox has a slice chamber 2 which is limited by a top wall 3 and a bottom wall 4 and a pair of side walls (not shown)
- the slice chamber has an upstream inlet 5 and a downstream outlet 6 and du ⁇ ng operation, the stock will pass from the inlet 5 to the outlet 6 such that the slice chamber can be descnbed as having an intended straight main direction of flow from the upstream inlet 5 to the downstream outlet 6
- Upstream of the slice chamber in the intended direction of flow of the stock there is a tube bank 18
- the tube bank 18 comp ⁇ ses several sections 7, 8, 9 of tubes that are vertically spaced from each other
- Each tube bank section in the tube bank comp ⁇ ses a plurality of straight tubes 10, 11, 12, 13, 14, 15 and the tubes in each tube bank section are arranged in separate vertically spaced rows, the rows extending m a cross machine direction
- Each tube has an upstream inlet end 16 through which stock is intended to enter the tube and a downstream outlet end 17
- the stock will thus flow in one and the same main direction of flow all the way from the upstream inlet end of the tubes in the tube bank to the downstream outlet of the nozzle chamber.
- the inventors have found that the straight flow of the stock all the way through the tube bank and the slice chamber contributes to a good coverage of the fibrous web and thereby also to a greater uniformity of the layer purity such that the formed fibrous web will have a cross section similar to the one indicated in FIG. 3.
- FIG. 3 a cross section of a 3-layered paper web is shown where the top and bottom layers may consist of short fibers while the middle layer may consist of long fibers.
- FIG. 5 shows a cross section of a paper web where the layers are mixed together with each other such that layer purity is poor.
- the headbox At the inlet of the slice chamber 2, interposed between the vertically spaced rows of tubes in the tube bank and connecting the tube rows to each other, the headbox is provided with elongate ledges 19 that extend in a cross machine direction.
- the elongate ledges 19 make possible the attachment of machine-wide separator vanes 20, 21 that subdivide the slice chamber into separate channels for the production of a multilayered fibrous web.
- FIG. 1 two separator vanes are shown but it is to be understood that the invention could equally well be applied to a headbox having only one separator vane or possibly three separator vanes.
- the separator vanes 20, 21, extend in the intended direction of flow of the stock and each of the machine-wide separator vanes 20, 21 has an upstream end 22 and a downstream end 23 and the upstream end of each separator vane is fastened to one of the elongate ledges interposed between the vertically spaced rows of tubes in the tube bank 18.
- the separator vanes are given a stiffness which is, on average, at least 36 Nm and which is , on a part of the separator vane stretching from the upstream end of the separator vane up to at least 7/10 (70 %) of the length of the separator vane, has a stiffness which is at least 7 Nm.
- the separator vanes will thereby have a stiffness which is, on average, at least 180 times greater than a 1 mm thick reference sheet or reference plate of a polycarbonate material having a modulus of elasticity of 2100 MPa and which, on a part of the separator vane stretching from the upstream end of the separator vane up to at least 7/10 of the length of the separator vane, has a stiffness in the cross machine direction which is at least 35 times greater than the stiffness of a 1 mm thick reference sheet or reference plate of a polycarbonate material having a modulus of elasticity of 2100 MPa.
- each separator vane is made of glass fiber reinforced epoxy resin having a modulus of elasticity of about 25,000 MPa and has a thickness calculated to result in an average stiffness of the separator vane in the cross machine direction which is at least 180 times higher than the stiffness of a 1 mm thick reference sheet of a polycarbonate material having a modulus of elasticity of 2100 MPa and a stiffness which , from the upstream end of the separator vane over at least 7/10 (70%) of the length of the separator vane, is at least 35 times higher than the stiffness of a 1 mm thick reference sheet (or reference plate) of a polycarbonate material having a modulus of elasticity of 2100 MPa.
- curve 1 shows (as a reference) the stiffness of a 1 mm thick reference sheet (or reference plate) of a polycarbonate material having a modulus of elasticity of 2100 MPa
- curve 2 shows the stiffness of a tapered separator vane of glass fiber reinforced epoxy resin according to the prefened embodiment of the present invention as compared to that of the 1 mm thick reference sheet.
- the average value of the stiffness is, in this case, about 36.2 Nm and thus about 181 times higher than the reference value of the 1 mm thick reference sheet of a polycarbonate material having a modulus of elasticity of 2100 MPa and has, for 7/10 of the length of the vane, a stiffness of at least 7.1 Nm and thus 35.5 times higher than the stiffness of a 1 mm thick reference sheet of a polycarbonate material having a modulus of elasticity of 2100 MPa.
- the separator vane has a thickness at its upstream end of approximately 3.8 mm.
- each separator vane The thickness decreases linearly towards the downstream end of each separator vane, the length of which may be on the order of 800 - 850 mm, (the inventors envisage that 830 mm is a suitable choice of separator vane length) and at the downstream end of the vane, the thickness will be on the order of approximately 0.5 mm.
- the inventors have found that, in order to achieve good layer purity, the thickness of the vanes should not exceed 0.7 mm at the downstream end of the separator vanes.
- the inventors envisage that the thickness at the downstream end may be around 0.5 mm and that the variation in the thickness should be no greater than 0.05 mm.
- the thickness is chosen to be lower than 0.7 mm in order to achieve a good layer purity.
- a thickness of about 0.5 is preferred. With regard to the coverage, it is preferable that the thickness variation is no greater than 0.05 mm.
- the material used for the separator vanes is isotropic in the sense that it has the same mechanical properties in both the machine direction and the cross machine direction. It is to be noted that the mechanical properties in the vertical dimension are not necessarily the same as in the machine direction and the cross machine direction. The material used is therefore not necessarily isotropic in the sense that it has the same mechanical properties in all directions.
- each separator vane is composed of a machine-wide upstream section 31 and a machine-wide downstream section
- the upstream section 31 has an upstream end which is the same as the upstream end of the separator vane itself, and a downstream end 33 to which the downstream section 29 is fixed
- the upstream section is composed of a steel plate of constant thickness while the downstream section 29 is made of glass fiber reinforced epoxy resm
- the steel plate has a modulus of elasticity of 203,000 MPa and its thickness is 12 mm
- the stiffness of the upstream section as stiffness is defined in the context of this application, can thus be calculated as being 32123 Nm and therefore 160615 times higher than the stiffness of the 1 mm reference sheet
- the downstream section has an upstream end 30 and a downstream end 23 common with the downstream end of the separator vane itself
- the upstream end 30 of the downstream section 29 is fixed to the downstream end 33 of an associated upstream section
- the downstream section has, at its upstream end, a
- curve 3 shows the stiffness of a separator vane according to the second embodiment of the invention compared to the stiffness of a 1 mm thick reference sheet (or reference plate) of a polycarbonate material having a modulus of elasticity of 2100 MPa
- the separator vane composed of an upstream section of constant thickness and a downstream tapered section has, du ⁇ ng a first part of its length (the upstream section which has a constant thickness), a constant stiffness
- the tapered downstream section has a gradually decreasing stiffness towards its downstream end
- the average stiffness of this vane will be considerably higher than 180 times the stiffness of a 1 mm thick reference sheet of a polycarbonate matenal having a modulus of elasticity of 2100 MPa
- the average stiffness of this separator vane as stiffness is defined m the context of this patent application, will be
- the stiffness will be higher than 57.1 Nm and therefore more than 280 times higher than the stiffness of the 1 mm thick reference sheet of a polycarbonate material having a modulus of elasticity of 2100 MPa which has a stiffness of 2.1 Nm.
- the slice chamber 2 of the headbox is further provided with a plurality of machine-wide turbulence generating elements 25, 26, 27 as can be seen in FIG. 9.
- Each turbulence generating element is located in one of the separate flow channels formed either between the top wall 3 and a separator vane 20, 21, between two separator vanes 20, 21 or between a separator vane 20, 21 and the bottom wall 4.
- Each of the machine-wide turbulence generating elements extends in the direction of flow of the stock and each turbulence generating element has an upstream end 34 and a downstream end 28.
- the upstream end 34 of each turbulence generating element 25, 26, 27 is interposed between two vertically spaced rows of tubes in the tube bank and fixed between said rows.
- the invention achieves that a multilayered fibrous web can be produced which has a good layer purity and a good coverage which assures that the layer purity will also be uniform.
- the fibrous web will have uniform strength properties across the web.
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP50150598A JP3194967B2 (en) | 1996-06-12 | 1997-05-29 | Multi-layer headbox for papermaking machine |
AT97927534T ATE223534T1 (en) | 1996-06-12 | 1997-05-29 | MULTI-LAYER HEADBOX FOR A PAPER MACHINE |
DE69715236T DE69715236T3 (en) | 1996-06-12 | 1997-05-29 | MULTILAYER RETURN FOR A PAPER MACHINE |
EP97927534A EP0939842B2 (en) | 1996-06-12 | 1997-05-29 | A multilayer headbox for a papermaking machine |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE9602347A SE506931C2 (en) | 1996-06-12 | 1996-06-12 | Multilayer inbox for a paper machine |
SE9602347-8 | 1996-06-12 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1997047804A1 true WO1997047804A1 (en) | 1997-12-18 |
Family
ID=20403001
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/SE1997/000921 WO1997047804A1 (en) | 1996-06-12 | 1997-05-29 | A multilayer headbox for a papermaking machine |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0939842B2 (en) |
JP (1) | JP3194967B2 (en) |
AT (1) | ATE223534T1 (en) |
DE (1) | DE69715236T3 (en) |
SE (1) | SE506931C2 (en) |
WO (1) | WO1997047804A1 (en) |
Cited By (4)
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EP1236828A1 (en) * | 2001-02-14 | 2002-09-04 | Voith Paper Patent GmbH | Trailing element of a head box of a paper, board or tissu machine |
EP1428929A1 (en) * | 2002-12-04 | 2004-06-16 | Voith Paper Patent GmbH | Headbox for a paper or board machine |
US7785446B2 (en) | 2004-10-05 | 2010-08-31 | Toray Industries, Inc. | Flow sheet for paper machine and method of manufacturing the same |
EP2707542A1 (en) * | 2011-05-11 | 2014-03-19 | Hollingsworth & Vose Company | Systems and methods for making fiber webs |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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CN101622399B (en) * | 2007-03-01 | 2012-10-17 | 梅特索·佩珀·卡尔斯塔德公司 | Structural element for a functional member of a headbox in a web-manufacturing machine, functional member and headbox made thereof, and associated methods |
DE102008000564A1 (en) * | 2008-03-07 | 2009-09-10 | Voith Patent Gmbh | Device for producing and / or treating a fibrous web |
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CH672515A5 (en) † | 1987-02-02 | 1989-11-30 | Escher Wyss Gmbh | |
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DE4329810C2 (en) † | 1993-09-03 | 1997-02-06 | Voith Gmbh J M | Geometry of the slat end of a headbox |
DE4440079C2 (en) † | 1994-11-10 | 1997-10-02 | Voith Sulzer Papiermasch Gmbh | Multi-layer headbox |
-
1996
- 1996-06-12 SE SE9602347A patent/SE506931C2/en not_active IP Right Cessation
-
1997
- 1997-05-29 JP JP50150598A patent/JP3194967B2/en not_active Expired - Lifetime
- 1997-05-29 AT AT97927534T patent/ATE223534T1/en active
- 1997-05-29 EP EP97927534A patent/EP0939842B2/en not_active Expired - Lifetime
- 1997-05-29 DE DE69715236T patent/DE69715236T3/en not_active Expired - Lifetime
- 1997-05-29 WO PCT/SE1997/000921 patent/WO1997047804A1/en active IP Right Grant
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1995008023A1 (en) * | 1993-09-13 | 1995-03-23 | Valmet-Karlstad Ab | A multilayer headbox |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1236828A1 (en) * | 2001-02-14 | 2002-09-04 | Voith Paper Patent GmbH | Trailing element of a head box of a paper, board or tissu machine |
EP1428929A1 (en) * | 2002-12-04 | 2004-06-16 | Voith Paper Patent GmbH | Headbox for a paper or board machine |
US7785446B2 (en) | 2004-10-05 | 2010-08-31 | Toray Industries, Inc. | Flow sheet for paper machine and method of manufacturing the same |
CN101040082B (en) * | 2004-10-05 | 2011-07-27 | 东丽株式会社 | Flow sheet for paper machine and method of manufacturing the same |
EP2707542A1 (en) * | 2011-05-11 | 2014-03-19 | Hollingsworth & Vose Company | Systems and methods for making fiber webs |
EP2707542A4 (en) * | 2011-05-11 | 2015-04-08 | Hollingsworth & Vose Co | Systems and methods for making fiber webs |
Also Published As
Publication number | Publication date |
---|---|
JPH11514050A (en) | 1999-11-30 |
DE69715236T3 (en) | 2006-12-14 |
DE69715236T2 (en) | 2003-05-22 |
DE69715236D1 (en) | 2002-10-10 |
EP0939842B2 (en) | 2006-06-28 |
SE9602347D0 (en) | 1996-06-12 |
EP0939842A1 (en) | 1999-09-08 |
ATE223534T1 (en) | 2002-09-15 |
SE9602347L (en) | 1997-12-13 |
JP3194967B2 (en) | 2001-08-06 |
EP0939842B1 (en) | 2002-09-04 |
SE506931C2 (en) | 1998-03-02 |
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