US3403073A

US3403073A - Paper-forming method and apparatus

Info

Publication number: US3403073A
Application number: US368843A
Authority: US
Inventors: Moran James
Original assignee: Time Inc
Current assignee: TI Gotham Inc
Priority date: 1964-05-20
Filing date: 1964-05-20
Publication date: 1968-09-24
Anticipated expiration: 1985-09-24

Description

J. MORAN PAPER-FORMING METHOD AND APPARATUS sept. 24, 1968 j 2 Sheets-Sheet l Filed May 20, 1964 o o IE w l INVENTOR,

JAMES MORAN ATTORNEYS,

Sept. 24, 1968 .1. MORAN PAPER-FORMING METHOD AND APPARATUS 2 Sheets-Sheet 2 Filed May 20, 1964 m m rml @m mm a JAMES MORAN BY g gvM/M/l" )L /rbb, GLM 4, rwd

his ATTORNEYS United States Patent O 3,403,073 PAPER-FORMING METHOD AND APPARATUS James Moran, Norwalk, Conn., assignor to Time, Incorporated, New York, N.Y., a corporation of New York Filed May 20, 1964, Ser. No. 368,843 6 Claims. (Cl. 162--203) This invention relates to paper-forming methods and apparatus and, in particular, to novel and highly-effective methods and apparatus facilitating the removal of water from a paper stock to form a paper web and the disposal of the water so removed.

Paper-forming apparatus typically comprises a pair of rolls and 1a foraminous stock-and-web-transporting element such as a Fourdrinier wire trained about the rolls and adapted to receive paper stock from a slice, facilitate removal of water from the stock so that the stock felts to form a web of paper, and transport the web to a press section for further processing. Conventional paper-forming methods and apparatus provide inadequate water-disposal capacity during high-speed operation and permit excessive loss of clay and fines from the stock and frequent disruption and other malformation of the web during the critical initial phases of the forming process. For all their shortcomings, convention-al paper-forming methods and apparatus also involve considerable expense.

A principal object of this invention is to remedy the problems outlined above. In particular, an object of the invention is to provide improved means for making paper, including paper of the highest quality. More particularly, an object of the invention is to provide means for gently removing large quantities of water from a paper stock in such a way `as to prevent excessive loss of clay and fines from the stock and dis-ruption and other malformation of the resulting paper web. Another object of the invention is to provide means for disposing of the water as quickly as it is removed from the web. A further object of the invention is to provide paper-forming apparatus and methods involving relatively little expense.

These .and other objects are accomplished by providing, in an exemplary embodiment of the invention, for an undulating movement of successive portions of -opposed forming wires through a forming zone, which undulating movement facilitates removal ofthe water from the stock, and for disposal of the removed water without substantially reducing its speed.

An understanding of further particulars of the invention may be obtained from a consideration of the following detailed description of several representative embodiments thereof in conjunction with the accompanying figures in the drawings, of which:

FIG..1 is a simplified or somewhat schematic side elevational view, partly in section, of a portion of paperforming apparatus constructed in accordance with the invention;

FIG. 2 is a sectional side elevational enlargement of a portion of FIG. 1;

FIG. 3 is a View, on a somewhat reduced scale, taken approximately along the line 3 3 of FIG. 2 and looking in the direction of the arrows; and

FIG. 4 is a View, on a further reduced scale, taken approximately along the line 4-4 of FIG. 3 and looking in the direction of the arrows.

The novel paper-making apparatus shown in FIG. l comprises first and second foraminous wires 11 and 12, respectively, and training means for training a portion of the first Wire 11 along a first reach and for training a portion of the second wire 12 .along a second reach. The word wire as used herein is generic not only to a Fourdrinier wire in a strict sense but also to other permeable or foraminous forming members adaped to `convey paper stock 3,403,073 Patented Sept. 24, 1968 ICC* and drain water therefrom to form a paper web. The portions of the wires 11, 12 which are trained along the first and second reaches are, respectively, the portions extending from an upstream region 14 immediately upstream of and adjacent to the upstream end 15 of a first sc-raper blade 16, past the first scraper blade 16 and second, third, and fourth scraper blades 17, 18, 19, and to a downstream region 20 immediately downstream of and adjacent to the downstream end 21 of the fourth scraper blade 19. One or more conventional vacuum boxes V may be placed downstream of the region 20 to facilitate further dewate-ring of the web.

The first reach along which the portion of the first wire 11 is trained is opposed and substantially parallel to and closely space-d apart from the second reach along which the portion of the second wire 12 is trained. A jet of stock 25 from a slice 26 is introduced between the portions of the wires 11 and 12 extending along the first and second reaches.

Drive means 27 is provided for rotating

breast rolls

28, 29 about their respective axes 28', 29 in the directions shown by the arrows. The drive means 27 may, of course, be connected to other rolls (no shown) instead of the

breast rolls

28, 29. Inasmuch as the wires 11, 12 are trained about the

rolls

28 and 29, respectively, suc cessive portions of the first wire 11 are driven along the first reach and successive portions of the second wire 12 along the second reach from the upstream region 14 to the downstream lregion 20. The drive means 27 is adjusted so that the wires 11, 12 move along the reaches at substantially the same speed and in substantially the same direction. The reaches define a paper-forming zone wherein water is removed from the paper stock 25 moving with the wires 11, 12 between the reaches to form a paper web. The word paper as used herein is generic not only to paper in a strict sense but also to paperboard and similar products.

In accordance with the invention, the training means mentioned above includes means 30 supported by framework F and imparting an undulation to the movement of the successive portions of the wires 11, 12 along the respective reaches. The means 30` in turn comprises a number of scraper blades such as the

blades

16, 17, 18, and 19. The scraper -

blades

16, 17, 18, 19 are of special construction, as will presently appear.

The first scraper blade 16 is mounted at the paperforming zone adjacent to the first wire 11 and on the side of the first wire 11 opposite the second wire 12 for skimming off water passing from the paper stock 25 through the first wire 11, expressing through the second wire 12 a quantity of water exceeding the quantity of water it expresses through the first wire 11, and facilitating the formation of the web of paper. The scraper blade 16 presents to the first wire 11 a smooth and convex surface 33 substantially impervious to water and having an extent in a direction transverse of the direction of web movement at least substantially as great as the width of the web.

The second scraper blade 17 is between the first blade 16 and the downstream region 20 and presents to the second wire 12 a smooth and convex surface 40 substantially impervious to water and having an extent in a direction transverse of the direction of web movement at least substantially as great as the width of the web. The blade 17 -skims off the water expressed by the blade 16 through the second wire 12 and, being impervious, expresses additional water through the first wire 11. The first and second scraper blades 16, 17 are spaced apart from each other in the direction of web movement and held firmly against the outer sides of the wires 11 and 12, respectively, to impart an undulation to the movement of the successive p-ortions of the first and second wires 11, 12 along the respective reaches.

The means 30 shown in FIG. 1 further comprises the third scraper blade 18 mounted at the paper-forming zone adjacent to the first wire 11 on the side of the first wire 11 opposite the second wire 12 and between the second scraper blade 17 and the downstream region 2t) for skimming `off water passing from the paper stock through the first wire 11 and facilitating the formation of the paper web. The third scraper blade 18 presents to the first wire 11 a smooth and convex surface 41 substantially impervious to water and having an extent in a direction transverse of the direction of web movement at least substantially as great as the width of the web. The blade 18 skims off the water expressed by the blade 17 t-hrough the first wire 11 and, being impervious, expresses additional water through the second wire 12.

The means 30 further comprises the fourth scraper blade 19 mounted at the paper-forming zone adjacent to the second wire 12 on the side of the second wire 12 opposite the first wire 11 and between the third scraper blade 18 and the downstream region 20 for skimming off water passing from the paper stock 25 through the second wire 12 and facilitating the formation of the paper web. The fourth scraper blade 19 presents to the second wire 12 a smooth and convex surface 45 substantially impervious to water and having an extent in a direction transverse of the direction of web movement at least substantially as great as the width of the web. The blade 19 skims off the water expressed by the blade 18 through the second wire 12 and, being impervious, expresses additional water through the first wire 11. The first, second, third, and

fourth scraper blades

16, 17, 18, 19 are held firmly against the outer sides of the

wires

11, 12, 11, and 12, respectively, to impart an undulation to the movement f the successive portions of the wires 11, 12 along the respective reaches.

The number of blades 16-19 constructed in accordance with the invention which should be used in a particular case may range between one and five or more, depending on the grade of paper being made and other factors, as those skilled in the art will readily understand. When an even number of blades 16-19 constructed in accordance with the invention is used, the first being mounted above the upper wire 11, as shown in the drawings, a conventional scraper blade B may be mounted between the downstream blade 19 and the vacuum box V to skim off the water expressed through the wire 11 by the blade 19. The blade B is, of course, connected to suitable water-disposal means (not shown).

FIG. 2 shows an exemplary construction of the scraper blades 16-19 in greater detail. All of the scraper blades 16-19 are preferably of the same construction except as regards the way in which their convex wire-contacting surfaces are curved; accordingly, only one of them, the blade 16, is illustrated in FIG. 2.

The blade 16 is formed with a sharp edge 35 facing the upstream region 14 and guiding the first wire 11 against the stock 25 to express water from the stock 25 through the first wire 11 as shown by the arrows and along the side 36 of the blade 16 opposite the convex surface 33. From to 20% of the water removed by the blade 16 is expressed through the wire 11 and passes along the side 36 of the blade 16. The remainder of the water removed by the blade 16 is removed largely downstream of the upstream edge 35 of the blade 16. Such water is expressed through the wire 12, inasmuch as no water can pass through the impervious surface 33. The water expressed without interruption through successive portions of the wire 12 as they traverse the part of the forming zone adjacent to the surface 33 is filtered not only by the wire 12 but also by the inchoate web on the wire 12. The filtration thus achieved results in better retention of clay and fiber `fines than is possible by means of conventional methods and apparatus.

The position and orientation of the blade 16 may be adjustable as a whole, and jack screws may be provided for adjusting the curvature of the surface 33. The generally-convex surface 33 of the blade 16 may be made of stainless steel, in which case it is adapted for use with a nylon or similar forming wire, or it may 'be provided with a smooth and abrasion-resistant 1/16 coating 33 of a substance such as Rockide C, which is a trademark of Norton Company for a chrome loxide which can be applied by spraying to a back-up plate.

In any case, the

surface

33 or 33 of the blade 16, though preferably not of the other blades 17, 18, .19, as will presently appear, includes a rst portion 50 curved .about a first axis parallel to the surface and a second portion 5.1 curved about a second axis parallel to the surface and the first axis. The first and second portions 50, 51 are continuous and curved smoothly one into the other. The second axis is substantially more distant from the surface 33 than is the first axis, and the second portion 51 is substantially larger than the first portion 50.

In accordance with a preferred embodiment of the scraper blades, the second axis is approximately two to three times as distant from the surface 33 as the first axis, and the second portion 51 is approximately twice the size of the first portion 50. More particularly, the second axis, or the axis about which the portion 51 is curved, may be approximately 24 feet from the surface 33, and the first axis, or the axis about which the portion 50 is curved, may be approximately 9 feet from the surface 33. The second portion may describe an arc of about 9 inches in length, i.e. in the direction of web movement, and the first portion 50 may describe an arc of about 5 inches in length.

The convex surfaces 40, 41, 45 of remaining blades 17, 18, 19 are preferably curved about single axes 24 feet distant from the respective surfaces.

The method of making paper in accordance with the invention comprises the steps of introducing the layer of paper stock 25 between the endless forming wires 11, 12 and moving the wires 11, 12 at substantially the same speed and in substantially the same direction along an undulating path facilitating the removal of water from the stock .alternately from opposite sides thereof.

In accordance with a preferred method 0f the invention, the wires 11, 12 describe at least one full wave in the forming zone. That is, at least two of the blades are employed, namely the blades 16, 17. In accordance with another embodiment of the invention, at least two f-ull waves .are described in the forming zone, all four of the blades .16, 17, 18, 19 being employed.

The invention also comprises water-disposal means mounted adjacent to the wires for disposing of water removed from the paper stock 2S. Water-disposal means 60, 61, 62, and 63 are shown in FIG. 1. The water-disposal means 60, 61 62, and 63 may be similar or identical, and only one, the water-disposal means 60, need be described in detail.

The water-disposal means 60, shown best in FIGS. 2, 3, and 4, comprises the previously-described scraper means 16 for skimming off water passing from the paper stock 25 through the first wire 11 and moving generally parallel to the successive portions of the wire 11 passing along the first reach. The water-disposal means 60 also includes means 65 (FIG. 3) for altering the direction of flow of the water to a direction generally transverse of the direction of movement of the successive portions of the wire 11 along the first reach without substantially reducing the speed of the water, which is thus disposed of while moving at a speed substantially equal to the speed of the stock at the slice.

The means 65 comprises a plurality of curved vanes or blades 66 (see also FIG. 4) mounted in spaced-apart relation to each other substantially across the width .of the sheet of water skimmed off by the scraper means 16. The varies 66 are curved through an angle for altering the direction of fiow of the water. Preferably, the direction of flow of the water after it has been altered is generally transverse of the direction of movement of the successive portions of the wire 11 along the first reach.

The water-disposal means 60 also comprises a ow chamber 70 (FIG. 2) having an entrance passage 71 for admitting to the chamber 70 a sheet of whitewater of given depth and flowing 'in a first direction tangent to the sheet, i.e. in the plane of the sheet rather than at an angle thereto. The chamber 70 is further provided with an exit passage 72 for releasing the whitewater from the chamber 70 to a transverse chamber 73 and an exit duct 74 as a fiuid flowing in a second `direction forming an angle with the first direction.

Each of the vanes 66 has a first edge 75 adjacent to the entrance passage 71 and facing oppositely to the direction of movement of the water as it enters the passage 71 and a second edge 76 adjacent to the exit passage 72 and facing in the direction of movement of the water as it leaves the passage 72. Each vane 66 is curved smoothly from the first edge 75 to the second edge 76 through ,an arc substantially equal in angular measure to the angle formed by the direction of movement of the fluid as it leaves the water-disposal means 65 with the direction of movement of the whitewater as it enters the chamber 70 in the form of a sheet. Each vane 66 has an extent normal to the sheet at least as great as the depth of the sheet. The cross-sectional flow area of the whitewater is maintained substantially constant during its passage through the water-disposal means 60. In particular, the back wall 73 of the chamber 73 is tapered so that the area of the chamber 73 increases towards the left side of FIG. 4 in accordance with the amount of water which must be accommodated. The taper of the wall 73 also facilitates the change in the direction of motion of the whitewater while maintaining its high velocity.

By virtue of this construction, the change in direction of the movement of the water is accomplished without substantially reducing the speed of the water, and the disposal of the water is therefore accomplished with maximum speed and efficiency. This means 60 (and 61,'62, and 63) for disposing of the removed water is particularly adapted for use in combination with the novel means for withdrawing the water from the web.

Thus there is provided in accordance with the invention novel and highly-effective apparatus for and methods of removing the water from a paper stock in a paperforming zone without removing appreciable amounts of clay and fines along with the water and without disrupting the stock as it felts to form a web of paper. As compared to prior-art apparatus, the novel paper-forming apparatus of the invention achieves a substantial reduction in the length of the forming zone and, simultaneously, a significant increase in the forming speed. The apparatus is, nevertheless, inexpensive to manufacture and repair, eliminating the need for table rolls and reducing the requirements for suction boxes.

Many modifications and form in detail of the representative embodiments of the invention disclosed herein will readily occur to those skilled in the art. Accordingly, the invention is to be construed as including all of the modifications which fall within the scope of the appended claims.

I claim:

1. Paper-forming apparatus comprising first and second endless forming wires, training means for training a portion of said first wire along a first reach and for training a portion of said second wire along a -second reach, said first reach being opposed and substantially parallel to and closely spaced apart from said second reach and said first and second reaches extending from an upstream region to a downstream region, and drive means for driving successive portions of said first wire along said first reach and for driving successive portions of said second wire along said second reach at substantially the same speed and in substantially the same direction from said upstream region to said downstream region, said portions defining a paper-forming zone wherein water is removed from a paper stock moving with said wires between said reaches to form a paper web of given width, said training means comprising a first scraper blade mounted at said paperforming zone adjacent to said first wire and on the side of said first wire opposite said second wire for skimming off water passing from the paper stock through said first wire, expressing through said second wire a quantity of water exceeding the quantity of water passing through said first Wire, and facilitating formation of the paper web and said scraper blade presenting to -said first wire a smooth and convex surface substantially impervious to water and having an extent in a direction transverse of the direction of web movement at least substantially as great as the Width of the web.

2. Apparatus as defined in claim 1 in which said training means further comprises a second scraper blade mounted at said paper-forming zone adjacent to said second wire and on the side of said second wire opposite said first wire for skimming off water passing from the paper stock through said second wire and facilitating formation of the paper web, said second scraper blade presenting to said second wire a smooth and convex surface substantially impervious to water and having an extent in a direction transverse of the direction of web movement at least substantially as great as the width of the web, said first and second scraper blades being spaced apart from each other in the direction of web movement and imparting an undulation to the movement of said successive portions along said respective reaches, said undulation facilitating the removal of the water.

3. A scraper blade adapted to be mounted adjacent to a reach along which a portion of an endless forming wire of a paper-making machine is trained and, when so mounted, to skim off water passing from a paper stock through said wire and facilitate formation of a paper web of given width, said blade having a generally cylindricallyconvex surface including a first portion curved about a first axis parallel to said surface and a second portion curved about a second axis parallel to said surface and said first axis, said first and second portions being continuous and curving smoothly one into the other, said second axis being substantially more distant from said surface than said first axis, said second portion being substantially larger than said first portion, and said surface having an extent parallel to said axes at least substantially as great as the width of the web.

4. Paper-forming apparatus comprising first and second endless forming wires, training means for training a portion of said first wire along a first reach and for training a portion of said second Wire along a second reach, said first reach being opposed and substantially parallel to and closely spaced apart from said second reach and said first and second reaches extending from an upstream region to a downstream region, drive means for driving successive portions of said first wire along said first reach and for driving successive portions of said second wire along said second reach at substantially the same speed and in substantially the same direction from said upstream region to said downstream region, said reaches defining a paper-forming zone wherein water is removed from a paper stock moving with said wires between said reaches to form a paper web, and water-disposal means mounted adjacent to said first wire for disposing of water removed from said paper stock, said water-disposal means comprising scraper means for skimming off water passing from the paper stock through said first wire and moving generally parallel to said successive portions and means for alterning the direction of flow of the water to a direction generally transverse of the direction of movement of said successive portions without substantially reducing the speed of the water.

5. Water-disposal apparatus adapted to be mounted adjacent to a reach along which successive portions of an endless forming wire of a paper-making machine are trained and moved and, when so mounted, to skim oi Water passing as a sheet from a paper stock through said Wire and moving generally parallel to said successive portions, the apparatus comprising a plurality of curved vanes mounted in spaced-apart relation to each other substantially across the width of said sheet for altering the direction of ow of the water to a direction generally transverse of the direction of movement of said successive portions While maintaining the cross-sectional low area of the water and thus the speed of the water substantiallyconstant.

6. A method of making paper comprising the steps of transporting a layer of paper stock in contact with an endless forming wire, expressing through said wire water from said paper stock to form from said paper stock a paper web, said water expressed through said wire moving generally parallel to said wire, and altering the direction of ow of the water to a direction generally transverse of the movement of the wire while maintaining the cross-sectional ow area of the water and thus the speed of the water substantially constant.

References Cited UNITED STATES PATENTS 2,141,393 12/1938 Hutchins 162-203 2,225,435 12/1940 Kellee 61 a1. 162-352X 2,881,676 4/1959 Thomas 162-203 3,066,068 11/1962 Calehuff etai 162.*208 3,102,066 8/1963 Justus 162-374X 3,201,305 8/1965 Webster 162-203 DONALL H. SYLVESTER, Primary Examiner.

ALBERT C. HODGSON, Assistant Examiner.

Claims

1. PAPER-FORMING APPARATUS COMPRISING FIRST AND SECOND ENDLESS FORMING WIRES, TRAINING MEANS FOR TRAINING A PORTION OF SAID FIRST WIRE ALONG A FIRST REACH AND FOR TRAINING A PORTION OF SAID SECOND WIRE ALONG A SECOND REACH, SAID FIRST REACH BEING OPPOSED AND SUBSTANTIALLY PARALLEL TO AND CLOSELY SPACED APART FROM SAID SECOND REACH AND SAID FIRST AND SECOND REACHES EXTENDING FROM AN UPSTREAM REGION TO A DOWNSTREAM REGION, AND DRIVE MEANS FOR DRIVING SUCCESSIVE PORTIONS OF SAID FIRST WIRE ALONG SAID FIRST REACH AND FOR DRIVING SUCCESSIVE PORTIONS OF SAID SECOND WIRE ALONG SAID SECOND REACH AT SUBSTANTIALLY THE SAME SPEED AND IN SUBSTANTIALLY THE SAME DIRECTION FROM SAID UPSTREAM REGION TO SAID DOWNSTREAM REGION, SAID PORTIONS DEFINING A PAPER-FORMING ZONE WHEREIN WATER IS REMOVED FROM A PAPER STOCK MOVING WITH SAID WIRES BETWEEN SAID REACHES TO FORM A PAPER WEB OF GIVEN WIDTH, SAID TRAINING MEANS COMPRISING A FIRST SCRAPER BLADE MOUNTED AT SAID PAPERFORMING ZONE ADJACENT TO SAID FIRST WIRE AND ON THE SIDE OF SAID FIRST WIRE OPPOSITE SAID SECOND WIRE FOR SKIMMING OFF WATER PASSING FROM THE PAPER STOCK THROUGH SAID FIRST WIRE, EXPRESSING THROUGH SAID SECOND WIRE A QUANTITY OF WATER EXCEEDING THE QUANTITY OF WATER PASSING THROUGH SAID FIRST WIRE, AND FACILITATING FORMATION OF THE PAPER WEB AND SAID SCRAPER BLADE PRESENTING TO SAID FIRST WIRE A SMOOTH AND CONVEX SURFACE SUBSTANTIALLY IMPERVIOUS TO WATER AND HAVING AN EXTENT IN A DIRECTION TRANSVERSE OF THE DIRECTION OF WEB MOVEMENT AT LEAST SUBSTANTIALLY AS GREAT AS THE WIDTH OF THE WEB.