DK155441B

DK155441B - Apparatus and process for producing fibre webs

Info

Publication number: DK155441B
Application number: DK141681A
Authority: DK
Inventors: Ii Cedric A Dunkerly
Original assignee: James River Norwalk Inc
Priority date: 1981-03-27
Filing date: 1981-03-27
Publication date: 1989-04-10
Also published as: DK141681A; DK155441C

Description

1 DK 155441B1 DK 155441B

OISLAND

Den foreliggende opfindelse angår et apparat og en fremgangsmåde til fremstilling af fiberbaner, såsom papir og lignende , specielt fremstilling af væv ved luftudlægning .The present invention relates to an apparatus and method for producing fibrous webs, such as paper and the like, in particular fabrication by air laying.

55

Ved fremstillingen af fiberbaner, såsom papir, ved' hjælp af luft .udlægnings metoden, må der drages omsorg for, at fordelingen af fibre på et formningstrådbånd bliver ensartet. Luft udlagte fiberbaner har en uønsket tendens 10 til at danne krusninger, som strækker sig på tværs af formningsbåndet, hvorved banen svækkes i fremføringsretningen.In the manufacture of fiber webs, such as paper, by means of the air laying method, care must be taken to ensure that the distribution of fibers on a forming wire band is uniform. Air laid fiber webs have an undesirable tendency 10 to form ripples which extend across the forming band, weakening the web in the feed direction.

Disse krusninget fremkommer, når der gøres forsøg på at arbejde med økonomiske, høje hastigheder af formningsbåndet, ud over en størrelsesorden på omkring 2,54 m/sek. - 2,79 15 m/sek. samt ved økonomiske lufthastigheder i en størrelsesorden på ca. 1,27 - 1,52 m/sek. gennem formningsbåndet. Der er ingen tendens til krusningsdannelse ved lavere hastigheder af formningsbåndet.These ripples appear when attempts are made to work at economical, high speeds of the forming band, in addition to an order of about 2.54 m / sec. - 2.79 15 m / sec. and at economic air velocities of the order of approx. 1.27 - 1.52 m / sec. through the forming band. There is no tendency for ripple formation at lower speeds of the forming band.

USA-patentskrift nr. 4.004.333, fig. 2, viser en 20 formningskanal 22A anbragt i en indfaldsvinkel B i forhold til en lineær, perforeret formningsflade 24A, hvorhos vinklen B er af størrelsesordenen omkring 10 - 30°, fortrinsvis ca. 20°. Ifølge patentet kan de forreste og bageste indvendige flader afvige fra hinanden ved en vinkel på ca.U.S. Patent No. 4,004,333; 2, shows a forming channel 22A disposed at an angle of incidence B relative to a linear, perforated forming surface 24A, where the angle B is of the order of about 10-30 °, preferably approx. 20 °. According to the patent, the front and rear inner surfaces may differ from each other at an angle of approx.

25 1 1/2°, men er fortrinsvis parallelle. Endvidere angives det, at formningsfladens hastighed kan være højere end 1,01 m/sek. Luftens hastighed gennem formningsfladen, den relative hastighed af fibrene i forhold til formningsfladen i dennes bevægelsesretning samt deres praktiske betydning 30 for en fordelagtig luftudlægning omtales ikke.1/2 °, but are preferably parallel. Furthermore, it is stated that the velocity of the forming surface can be higher than 1.01 m / sec. The velocity of the air through the forming surface, the relative velocity of the fibers relative to the forming surface in its direction of movement, as well as their practical significance 30 for advantageous air laying are not mentioned.

USA-patentskrift nr. 4.035.870 viser et fiberledningsrør 10 og en formningsklokke 14 anbragt koaksialt på linie langs en akse, som danner en spids vinkel med formningsfladen 16 af et bånd 17, så fibrene afsættes på 35 fladen 16 i en retning, som har en vektorkomposant, der falder sammen med fladen 16's bevægelsesretning.U.S. Patent No. 4,035,870 discloses a fiber conduit 10 and a molding bell 14 coaxially aligned along an axis forming an acute angle to the forming surface 16 of a strip 17 so that the fibers are deposited on the surface 16 in a direction which a vector component that coincides with the direction of movement of the surface 16.

OISLAND

2 DK 1554413 USA-patentskrift nr. 3.748.693 viser vinger 54 i en sugekasse 34 med øverste og nederste luftudstrømningsåbninger 38. Vingerne 54 strækker sig på tværs af bevægelsesretningen af et formningsbånd 30 og er selektivt ind-5 stillelige til differential begrænsning af luftstrømmen gennem båndet 30, således at banens tykkelse kan ændres.US Patent No. 3,748,693 discloses blades 54 in a suction box 34 with upper and lower air outlet openings 38. Blades 54 extend transversely to the direction of motion of a forming belt 30 and are selectively adjustable for differential air flow control through the band 30 so that the thickness of the web can be changed.

Det er formålet med opfindelsen at tilvejebringe et apparat og en fremgangsmåde til fremstilling af luftad-lagte fiberbaner, som i hovedsagen er fri for krusnin-10' ger. I det følgende beskrives midler til ensartet fordeling af fibermateriale på et formningsbånd i et apparat til fremstilling af fiberbaner.It is an object of the invention to provide an apparatus and method for manufacturing air-adapted fiber webs which are substantially free of ripples. The following describes means for uniform distribution of fibrous material on a forming band in a fiber web manufacturing apparatus.

Den foreliggende opfindelse tilvejebringer et apparat til fremstilling af fiberbaner, omfattende et organ til fordeling 15 af tørre fibre, et formningsbånd, hvoraf et plant afsnit er anbragt neden under fordelingsorganet og er lineært bevægeligt ved en forud fastsat, første hastighed, og en sugekasse anbragt neden under det plane afsnit af formningsbåndet til at trække luft gennem formningsbåndet med en forud fastsat, anden hastig-20 hed vinkelret på nævnte plane afsnit, hvilket apparat er ejendommeligt ved midler til meddelelse af en vandret hastigheds-komposant, som er mindre end den første hastighed, til fibrene i formningsbåndets bevægelsesretning, hvilke midler bevirker, at fibrene rammer formningsbåndet under dannelse af en vinkel 25 på 21 - 30° med dette, når den anden hastighed er højere end ca. 1,27 m/sek., og den første hastighed er højere end ca.The present invention provides an apparatus for making fiber webs, comprising a means for distributing dry fibers, a forming band, a flat section of which is disposed below the distributing means and is linearly movable at a predetermined first speed, and a suction box disposed below below the planar section of the forming belt for drawing air through the forming belt at a predetermined second velocity perpendicular to said planar section, which is peculiar to means for communicating a horizontal velocity component less than the first velocity , for the fibers in the direction of motion of the forming belt, which means causes the fibers to hit the forming belt to form an angle 25 of 21 - 30 ° therewith, when the second speed is higher than approx. 1.27 m / sec, and the first speed is higher than approx.

2,54 m/sek.2.54 m / sec.

Opfindelsen tilvejebringer desuden et apparat til fremstilling af fiberbaner, omfattende et fiberfordelingsorgan med en 30 bund, en vandret beliggende åbning, et formningsbånd, hvoraf et plant afsnit er anbragt neden under nævnte åbning og er lineært bevægeligt ved en forud fastsat, første hastighed, samt en sugekasse neden under nævnte plane afsnit til at trække luft gennem formningsbåndet med en forud fastsat, anden hastigheds-35 komposant vinkelret på formningsbåndet, hvilket apparat er ejendommeligt ved, at sugekassen delvis er dannet af parallelle forreste og bageste vægge, som strækker sig på tværs af formningsbåndets bevægelsesretning og skråt nedad i nævnte bevægel-The invention further provides an apparatus for producing fiber webs comprising a fiber distribution means having a bottom, a horizontally located aperture, a forming band, a flat section of which is arranged below said aperture and is linearly movable at a predetermined first speed, and a suction box below said planar section for drawing air through the forming belt with a predetermined second velocity component perpendicular to the forming belt, which is characterized in that the suction box is partly formed by parallel front and rear walls extending across the direction of movement of the forming belt and inclined downwardly in said movement.

OISLAND

3 DK 155441B3 DK 155441B

sesretning under dannelse af en vinkel på 21 - 30° med det vandrette plan, hvorhos en øverste kant af den forreste væg er anbragt i afstand bagudtil fra fordelingsorganets bundåbning, hvorved der dannes et mellemrum, som strækker sig 5 på tværs af formningsbåndéts bevægelsesretning, hvorhos en udstrømningsåbning er anordnet i et nederste område af sugekassen i nærheden af en nederste kant af den bageste væg, og en tætningsrulle strækker sig på tværs af formningsbåndets bevægelsesretning og delvis dækker nævnte mellem-10 rum. Herved meddeles luft og fibre en vandret hastigheds-komposant i formningsbåndets bevægelsesretning, som er mindre end nævnte første hastighed.viewing direction to form an angle of 21-30 ° with the horizontal plane at which a top edge of the front wall is spaced backwardly from the bottom opening of the distributor, thereby forming a gap extending 5 across the direction of movement of the forming band, wherein an outflow opening is provided in a lower region of the suction box in the vicinity of a lower edge of the rear wall, and a sealing roller extends transversely of the direction of movement of the forming belt and partially covers said space. Hereby air and fibers are communicated a horizontal velocity component in the direction of motion of the forming belt which is less than said first velocity.

! Endelig tilvejebringer opfindelsen en fremgangsmåde til fremstilling af fiberbaner, som i hovedsagen er fri for tvær-15 gående krusninger, hvilken fremgangsmåde er ejendommelig ved, at fibrene i en strøm føres til et plant afsnit af et formningsbånd, medens dette bevæges med en hastighed på mere end 2,54 m/sek., idet vinklen, hvorunder nævnte strøm rammer det plane afsnit, holdes på 21 - 30°, og idet der 20 opretholdes et trykfald gennem det plane afsnit ved at luft bringes til at strømme derigennem med en hastighed vinkelret på det plane afsnit på mere end 1,27 m/sek.! Finally, the invention provides a method of producing fiber webs which are substantially free of transverse ripples, characterized in that the fibers are fed in a stream to a flat section of a forming belt while moving at a rate of more than 2.54 m / sec, keeping the angle at which said current hits the planar section at 21-30 ° and maintaining a pressure drop through the planar section by causing air to flow therethrough at a speed perpendicular on the plane section of more than 1.27 m / sec.

Opfindelsen skal i det følgende beskrives nærmere under henvisning til tegningen, på hvilken 25 fig. 1 skematisk viser et lodret snit gennem dele af apparatet, fig. 2 en ændret udførelsesform for apparatet ifølge fig. 1, 30 fig. 3 en ændret udførelsesform for apparatet iføl ge opfindelsen, fig. 4 en ændret udførelsesform for apparatet ifølge opfindelsen, fig. 5 en ændret udførelsesform for apparatet iføl-35 ge opfindelsen, fig. 6 en ændret udførelsesform for apparatet ifølge opfindelsen, 4The invention will now be described in more detail with reference to the drawing, in which FIG. 1 is a schematic vertical section through parts of the apparatus; FIG. 2 shows a modified embodiment of the apparatus according to FIG. 1, 30 FIG. 3 shows a modified embodiment of the apparatus according to the invention; FIG. 4 shows a modified embodiment of the apparatus according to the invention; FIG. 5 shows a modified embodiment of the apparatus according to the invention; FIG. 6 shows a modified embodiment of the apparatus according to the invention; 4

OISLAND

DK 1:.5441 BDK 1: .5441 B

fig. 7 en ændret udførelsesform for apparatet i-følge opfindelsen, og fig. 8 en ændret udførelsesform for apparatet i-følge opfindelsen.FIG. 7 shows a modified embodiment of the apparatus according to the invention; and FIG. 8 shows a modified embodiment of the apparatus according to the invention.

5 Fig. 1 viser et apparat 10 til fremstilling af en bane af fibermateriale. Apparatet omfatter et sæt fordelingsorganer 11, som hver har et vingehjul, hvoraf et er vist ved 19. Vingehjulene 19 er anbragt oven over et vandret, plant afsnit af et formningsbånd 12, som understøttes 10 for bevægelse af passende anbragte ruller 13 og 14. Rullerne er drejelige for bevægelse af den øverste bane af formningsbåndet i retning af pilen A. Under driften bevæger formningsbåndet 12 sig med en forud fastsat hastighed V^. Sugekasser 15 er anbragt neden under formningsbåndet 12, og 15 begge er forsat ved deres højre bagkant i båndets fremføringsretning (dvs. i arbejdsretningen) i forhold til den tilsvarende kant af fordelingsQrgauet 11. Et par parallelle rand- eller sideplader er tilvejebragt langs siderne af formningsbåndet 12 ved hvert fordelingsorgan 11, 20 hvoraf kun en plade 20 af hvert par er vist. En blæser 16 har sin indgang 16a forbundet med sugekasser 15, og dens udløb 16b ender i atmosfæren. Blæseren 16 er virksom til dannelse af en luftstrøm nedad gennem det vandrette, øverste baneafsnit af formningsbåndet 12, idet luftstrømmen 25 er vinkelret herpå, og med en hastighed som er ca.FIG. 1 shows an apparatus 10 for producing a web of fibrous material. The apparatus comprises a set of distribution members 11, each having a wing wheel, one of which is shown at 19. The wing wheels 19 are arranged above a horizontal, flat section of a forming belt 12 supported 10 for movement of suitably arranged rollers 13 and 14. The rollers are rotatable for movement of the upper web of the forming belt in the direction of the arrow A. During operation, the forming belt 12 moves at a predetermined speed V ^. Suction boxes 15 are located below the forming belt 12 and both are positioned at their right rear edge in the conveying direction (ie in the working direction) relative to the corresponding edge of the distribution curve 11. A pair of parallel edge or side plates are provided along the sides of the forming belt 12 at each distributor 11, 20 of which only one plate 20 of each pair is shown. A fan 16 has its input 16a connected to suction boxes 15, and its outlet 16b ends in the atmosphere. The fan 16 is operable to form a downward flow of air through the horizontal upper web section of the forming belt 12, the airflow 25 being perpendicular thereto, and at a rate of about

1,27 m/sek. eller fortrinsvis derover.1.27 m / sec. or preferably above.

En række bueformede blade 17 strækker sig tværs over bundåbningen 11a af hvert fordelingsorgan 11 mellem pladerne 20. Bladene 17 i hver række er ensdannede, er anbragt 30 med samme indbyrdes afstand og stilling og strækker sig på tværs af formningsbåndets 12’s bevægelsesretning A. Hvert blad 17 er et 90° afsnit af en hul, lige, cirkulær cylinder og er således anbragt, at tangenten til den øverste kant står hovedsagelig vinkelret på åbningen 11a's plan, dvs.A series of arcuate blades 17 extend across the bottom opening 11a of each distributor 11 between the plates 20. The blades 17 in each row are uniformly formed, are spaced 30 at the same spacing and position, and extend across the direction of movement of the forming belt 12. is a 90 ° section of a hollow, straight, circular cylinder and is arranged such that the tangent to the upper edge is substantially perpendicular to the plane of the opening 11a, i.e.

er i hovedsagen parallel med strømmen af luft og fibre fra fordelingsorganet, og tangenten til den nederste kant er i hovedsagen parallel med formningsbåndets bevægelsesretning 35is substantially parallel to the flow of air and fibers from the distributor, and the tangent to the lower edge is substantially parallel to the direction of movement of the forming belt 35

OISLAND

5 DK 155441B5 DK 155441B

og er anbragt i en afstand på fortrinsvis 6,3 mm over dette. Bladene er anbragt i afstand fra hinanden, således at tangenten T til den øverste kant af et blad gennemskærer det nederste kantområde af det mod strømningsretningen 5 næste blad, dvs. det næste blad til venstre i fig. 1.and is spaced preferably 6.3 mm above it. The blades are spaced apart so that the tangent T to the upper edge of a blade intersects the lower edge region of the blade next to the flow direction 5, i.e. the next leaf to the left in fig. First

Ifølge opfindelsen er den bageste kant af sugekasserne 15's forsatte del, kombineret med formen og anbringelsen af bladene 17 således, at luften· samt de af luften medbragte fibre, som strømmer mellem fordelings-10 organerne 11's bundåbninger 11a og formningsbåndets 12's overflade via mellemrummene mellem bladene 17, tildeles en hastighedskompo'sant . Den omgivende luft, som trækkes ind ved S, forøger den vandrette komposant V^, medens den omgivende luft, som trækkes ind ved S* medvirker til at 15 fastholde banen på formningsbåndet. Dette vil være tilfældet for de forskellige udførelsesformer, hvor det er antydet.In accordance with the invention, the trailing edge of the suction boxes 15 is offset, combined with the shape and placement of the blades 17, such that the air · and the fibers carried by the air flow between the bottom openings 11a of the distribution means 11 and the surface of the forming belt 12 via the spaces between the blades 17, a speed component is assigned. The ambient air drawn in by S increases the horizontal component V1, while the ambient air drawn in by S * helps to maintain the web on the forming band. This will be the case for the various embodiments where indicated.

Den vandrette hastighedskomposant er mindre end hastigheden af formningsbåndet, idet denne fortrinsvis er over 2,54 m/sek. Det stykke, hvormed den er forsat er af en 20 sådan størrelsesorden, at der dannes en strøm af luft og tørre fibre (fra åbningerne 11a til formningsbåndet 12), som strækker sig nedad i en vinkel H på omkring 21-30°, målt fra den vandret forløbende, øverste bane af formningsbåndet. Den spidse vinkel, hvorunder fibrene rammer båndet 25 12, er baseret på en konstatering af, at der opnås en gun stig fiberbanedannelse, fri for krusninger på tværs af formningsbåndet (dvs. på tværs af dets bredde og på tværs af arbejdsretningen), hvis forholdet mellem den samlede tangentialhastighed i forhold til formningsbåndet 12 (dvs.The horizontal velocity component is less than the velocity of the forming band, preferably being above 2.54 m / sec. The piece with which it is set is of an order of magnitude to form a stream of air and dry fibers (from the openings 11a to the forming band 12) extending downwardly at an angle H of about 21-30 °, measured from the horizontally extending upper web of the forming band. The acute angle at which the fibers strike the band 25 12 is based on the finding that a gun rise fiber web formation is obtained, free of ripples across the forming band (i.e., across its width and across the working direction), if the ratio between the total tangential velocity relative to the forming band 12 (i.e.

30 V-^-V^) og den ved hjælp af sugekassen indførte gennemstrøm ningslufts hastighed vinkelret på formningsbåndet (dvs.30 V - V - V) and the velocity of the air flow introduced by means of the suction box perpendicular to the forming belt (i.e.

V2) ikke er større end 2,5:1, hvor 2,5 er cotangens af den spidse vinkel H, da^er lig med ca. 22°. Den på båndet 12 formede, ikke viste bane fjernes fra båndet 12 ved hjælp af et passende, ikke vist apparat, inden bandet bevæger sig hen over rullen 14.V2) is not greater than 2.5: 1, where 2.5 is the cotangent of the acute angle H since ^ is equal to approx. 22 °. The web, not shown, formed on the belt 12 is removed from the belt 12 by a suitable apparatus, not shown, before the belt moves over the roller 14.

35 635 6

OISLAND

DK 115441 BDK 115441 B

I den i fig. 2 viste udførelsesfonn, omfatter apparatet 110 fordelingsorganer 111, hvoraf kun ét er vist, under hvilket der findes et plant afsnit af et formnings^ bånd 112, som er bevægeligt i retningen A ved en forud fast-5 sat hastighed V^. Sugekassen 115 er anbragt direkte neden under båndet 112 og er ligeledes anbragt på linie med fordelingsorganet 111 ved sin i strømningsretningen bageste ende, men er forsat ved sin højre, i strømningsretningen bageste ende eller bagkant. Den Ønskede, fordelagtige vin-10 kelstrøm af fibre fra åbningen 111a ned på båndet 112 opnås ved hjælp af en række parallelle, med samme indbyrdes afstand anbragte, flade ledeplader 117, som strækker sig hen .over åbningen 111a i en retning på tværs af båndets bevægelsesretning A og under dannelse af en spids vinkel H med 15 det vandret forløbende formningsbånd, hvilken vinkel er ca. 21-30°. Pladerne 117 ér fortrinsvis således anbragt, at deres øverste ender lodret flugter med en flad del af en tilstødende plade. Denne anbringelse og dette vinkelforhold i kombination med hastigheden V2 af luft vinkelret på form-20 ningsbåndet 112 bibringer fibrene den ønskede, vandrette hastighedskomposant Vg som beskrevet ovenfor.In the embodiment shown in FIG. 2, the apparatus 110 comprises distribution means 111, only one of which is shown, below which is a flat section of a forming band 112 which is movable in the direction A at a predetermined speed V1. The suction box 115 is located directly below the belt 112 and is also aligned with the distributor 111 at its rear end in the flow direction, but is positioned at its right, rear end or rear edge. The desired advantageous angular flow of fibers from the aperture 111a down to the strip 112 is obtained by a series of parallel, spaced-apart flat baffles 117 extending across the aperture 111a in a direction transverse to that of the strip. direction of movement A and forming a pointed angle H with the horizontally extending forming band, which angle is approx. 21-30 °. The plates 117 are preferably arranged such that their upper ends are aligned vertically with a flat portion of an adjacent plate. This arrangement and this angular relationship in combination with the velocity V2 of air perpendicular to the forming belt 112 impart the fibers to the desired horizontal velocity component Vg as described above.

Det i fig. 3 viste apparat 210 indbefatter et fordelingsorgan 211, som har en udstrømningsåbning 211a anbragt på linie med sugekassen 215. Formningsbåndet 212 25 er. bevægeligt i retningen A som ved de ovenfor beskrevne udførelsesformer, og sideplader 220 strækker sig mellem fordelingsorganet og formningsbåndet. Denne udførelsesformer karakteriseret ved en ledeplade 215a, som strækker sig vandret fra den venstre, eller forreste kant af sugekassen 30 215 og hen over en del af den øverste, vandrette sugekasse- åbning 215b, som befinder sig neden under formningsbåndet. Ledepladen 215a strækker sig på tværs af båndet 212's bevægelsesretning A og er således dimensioneret i retningen A, at en linie, som gennemskærer den venstre kant E af åb-35 ningen 211a i fordelingsorganet 211 og den fri kant E' af ledepladen 215a danner en spids vinkel H med det vandrette plan til opnåelse af den ønskede vinkelluftstrøm. Den øn-The FIG. 3, a distributor 211 has a discharge port 211a arranged in line with the suction box 215. The forming belt 212 25 is. movable in the direction A as in the above-described embodiments, and side plates 220 extend between the distributor and the forming belt. This embodiment is characterized by a baffle 215a extending horizontally from the left or front edge of the suction box 30 215 and across a portion of the upper horizontal suction box opening 215b located below the forming belt. The guide plate 215a extends across the direction A of the belt 212 and is dimensioned in the direction A such that a line intersecting the left edge E of the opening 211a of the distributor 211 and the free edge E 'of the guide plate 215a forms a tip. angle H with the horizontal plane to obtain the desired angular air flow. The island

OISLAND

7 DK 1B5441 B7 DK 1B5441 B

skede, skrå luftstrøm fremmes yderligere ved anbringelse af en luftudstrømningsåbning P-2 i sugekassen 215 i et afgangsområde af denne.sheath, oblique air flow is further promoted by placing an air outlet opening P-2 in the suction box 215 in a discharge area thereof.

Endnu en udførelsesform for apparatet er vist 5 ved 310 i fig. 4 og indbefatter et fordelingsorgan 311 og sideplader 320 som beskrevet ovenfor, samt et formningsbånd 312, som er bevægeligt derunder i retningen A. En sugekasse 315 er anbragt neden under formningsbåndet, hovedsagelig på linie med fordelingsorganet. En lodret skil-10 levæg 315a strækker sig tværs over sugekassen neden under formningsbåndet 312 og er anbragt mod den forreste side af sugekassen i forhold til formningsbåndets bevægelse. Den øverste kant F af den lodrette ledeplade 315a er således anbragt, at en linie, som berører den og den forreste 15 kant F' af fordelingsorganets åbning 311a danner en spids vinkel H på omkring 30° med det vandrette plan. Udstrømningsåbningen P-3 er anbragt i den højre, i strømningsretningens bageste afdeling af sugekasse 315, så at strømningen af luft gennem udstrømningsåbningen til indstrømnings-20 åbningen i en ikke vist sugepumpe yderligere sikrer en opnåelse af den ovenfor beskrevne, ønskede skrå strøm af luft og fibre. En renseåbning C er tilvejebragt for at lette fjernelsen af eventuelle fibre eller støv, som falder ned i den døde zone mellem ledepladen 315a og den i strømningsretningen forreste væg af sugekassen 315.Yet another embodiment of the apparatus is shown 5 at 310 in FIG. 4 and includes a distributor 311 and side plates 320 as described above, and a forming belt 312 movable thereunder in the direction A. A suction box 315 is disposed below the forming belt, generally in line with the distributor. A vertical partition wall 315a extends across the suction box below the forming belt 312 and is positioned against the front side of the suction box relative to the forming belt movement. The upper edge F of the vertical baffle 315a is arranged such that a line touching it and the front edge F 'of the opening member 311a forms an acute angle H of about 30 ° with the horizontal plane. The outlet opening P-3 is located in the right, in the rear direction of the flow direction, of suction box 315, so that the flow of air through the outlet opening to the inlet opening of a suction pump not shown, further ensures the desired desirable oblique flow of air described above. fibers. A cleaning opening C is provided to facilitate the removal of any fibers or dust falling into the dead zone between the baffle 315a and the wall of the suction box 315 in the direction of flow.

En yderligere udførelsesform er vist ved 410 i fig. 5, og omfatter et formningsbånd 412, som er bevægeligt i retningen A neden under åbningen 411a i et fordelingsorgan 411, som er forsynet med sideplader 420. En sugekas-30 se 415 er anbragt neden under båndet 412 i flugt med fordelingsorganet 411. Sugekassen 415 har et endeløst bånd 415c, som er bevægeligt i retningen af pilen B overfortandede ruller R og R', og som er anbragt forrest set i båndets bevægelsesretning A, og det strækker sig på tværs af den-35 ne. En udstrømningsåbning P-4 i området efter båndet 415e fører til en indstrømningsåbning 416a i en sugepumpe til opnåelse af en uensartet strøm i en forud fastsat, ønsket spids vinkel H med det vandrette plan, hvilket tilvejebringes 8A further embodiment is shown at 410 in FIG. 5, and comprises a forming belt 412 which is movable in the direction A below the opening 411a of a distributor 411 provided with side plates 420. A suction box 415 is disposed below the belt 412 in flight with the distribution member 411. The suction box 415 has an endless belt 415c which is movable in the direction of the arrow B over-rolled rollers R and R ', which is positioned at the front as seen in the direction of movement of the belt A and extends transversely thereto. An outflow opening P-4 in the area after the belt 415e leads to an inlet opening 416a in a suction pump to obtain a uniform flow at a predetermined desired angular angle H with the horizontal plane, which is provided 8

DK Ir,5441 BDK Ir, 5441 B

OISLAND

ved båndet 415c's skærmvirkning. En roterende børste 418 er i kontinuerlig kontakt med båndet 415c's nederste bane til fjernelse af eventuelt støv eller fibre, som passerer gennem formningsbåndet 412 og lander på båndet 415c. En linie, 5 som berører eller passerer gennem den øverste kant af for- ! delingsorganets åbning 411a og tangerer den bageste ende af båndet, danner en vinkel H med det vandrette plan.by the screen effect of the tape 415c. A rotating brush 418 is in continuous contact with the lower web of the belt 415c to remove any dust or fibers passing through the forming belt 412 and landing on the belt 415c. A line, 5 which touches or passes through the upper edge of the front! the dividing member opening 411a and tangent to the rear end of the belt, forming an angle H with the horizontal plane.

Det ved 510 viste udførelsesform i fig. 6 svarer til den i fig. 5 viste udførelsesform i den henseende, 10 at den har sideplader 520 samt et formningsbånd 512, som er bevægeligt i den ved pilen A viste retning neden under åbningen 511a i et fiberfordelingsorgan 511. En sugekasse 515 er anbragt neden under formningsbåndet i flugt med for-delingsorganet 511. Sugekassen 515 har en udgangsåbning 15 P-6 i nærheden af den bageste side af sugekassen 515, som fører til en indgangsåbning 516a i en sugepumpe til opnåelse af en strømning gennem formningsbåndet 512 under dannelse af en forudbestemt, spids vinkel H med det vandrette plan. Et bånd 515a er bevægeligt over på tværs af formningsbåndet 20 anbragte kæderuller R" og fremmer afbøjningen af strømmen af fibre og luft mellem fordelingsorganet 511 og formningsbåndet 512. En roterende børste 515c renser båndets515a's nederste løb, idet den på hensigtsmæssig måde fjerner støv og fibre, som samler sig på båndet som følge af gennemstrøm-25 ningen gennem formningsbåndet.The embodiment shown at 510 in FIG. 6 is similar to that of FIG. 5 in that it has side plates 520 and a forming belt 512 which is movable in the direction shown by arrow A below the opening 511a in a fiber distribution means 511. A suction box 515 is arranged below the forming belt in flight with The suction box 51. The suction box 515 has an outlet opening 15 P-6 near the rear side of the suction box 515 which leads to an inlet opening 516a in a suction pump to obtain a flow through the forming belt 512 to form a predetermined, acute angle H with it. horizontal plane. A belt 515a is movable across chain rolls R "across the forming belt 20 and promotes the deflection of the flow of fibers and air between the distributor 511 and the forming belt 512. A rotating brush 515c cleans the lower bore of the belt 515 by appropriately removing dust and fibers. which accumulates on the belt as a result of the flow through the forming belt.

Den ved 610 viste udførelsesform i fig. 7 omfatter et fordelingsorgan 610 med sideplader og med en bundåbning 611a anbragt oven over et formningsbånd 612, som er bevægeligt i retning af pilen A. En sugekasse 615 er anbragt 30 neden under formningsbåndet, så at dens øverste åbning, som er lidt større end åbningen 611a, har sin forreste kant anbragt på linie med den tilsvarende kant af åbningen 611a, medens dens bagkant er anbragt lidt forbi åbningen 611a.The embodiment shown at 610 in FIG. 7 comprises a distributor 610 having side plates and having a bottom opening 611a disposed above a forming belt 612 which is movable in the direction of arrow A. A suction box 615 is placed below the forming belt so that its upper opening slightly larger than the opening 611a, its leading edge is aligned with the corresponding edge of the opening 611a, while its trailing edge is positioned slightly past the opening 611a.

En tætningsrulle 618 er anbragt til rotation på en akse, 35 som strækker sig på tværs af formningsbåndet, så at dens øverste, venstre kvadrant ligger tæt ved kanten af åbningen 611a, og dens nederste flade er i fuld berøring med en på båndet 612 dannet bane. I den viste konstruktion af sugekassen 615 er der et mellemrum mellem bagkanten af dens åbningA sealing roller 618 is arranged to rotate on an axis 35 extending across the forming belt such that its upper left quadrant lies close to the edge of the opening 611a and its lower surface is in full contact with a web formed on the belt 612 . In the shown construction of the suction box 615 there is a gap between the trailing edge of its opening

OISLAND

9 r~\ i v /i i' r ,·ι i'. <\ r~59 r ~ \ i v / i i 'r, · ι i'. <\ r ~ 5

UK ! :·0^Γ ! DUK! : · 0 ^ Γ! D

og rullen 618. Kassen 615 har hovedsagelig parallellogram-form set fra siden, og dens forreste og bageste vægge 615d og 615e strækker sig skråt nedad og i strømningsretning i en vinkel på ca. 30° med det vandrette plan. En udstrøm-5 ningsåbning P-7 er anbragt i et bageste hjørne af sugekassen. Konstruktionen og anbringelsen af denne udførelsesform er sådan, at luft og fibre vil ramme formningsbåndet 612 under dannelse af en spids vinkel H på ca. 30° med dette.and the roller 618. The box 615 has a substantially parallelogram side view, and its front and rear walls 615d and 615e extend obliquely downwards and in the direction of flow at an angle of approx. 30 ° with the horizontal plane. An outflow opening P-7 is located in a rear corner of the suction box. The construction and arrangement of this embodiment is such that air and fibers will hit the forming belt 612 to form an acute angle H of approx. 30 ° with this.

Den i fig. 8 viste udførelsesform omfatter et appa-10 rat 710 i lighed med det i fig. 7 viste, indbefattende konstruktionen af fordelingsorganet 711 og dettes åbning 711a, formningsbåndet 712 og dettes bevægelsesretning A, sidevægge 720, samt tilvejebringelsen af en tætningsrulle 718. Sugekassen 715 er i hovedsagen trapezformet og har en skrå 15 bagkant 715e, hvis øverste kant er anbragt lidt foran tæt-ningsrull’en 718. Sugekassen 715 har også en forreste, skråt forløbende væg 715d, hvis øverste kant er anbragt lidt bagved den forreste kant af åbningen 711a, idet denne væg udgør en skillevæg i kassen 715. Sugekassen 715 har også en forres= 20 te forlængelse defineret af en lodret væg 715f i kombination med væggen 715d samt en forlængelse parallel med 715c[ i sugekassens nederste væg. En renseåbning C-7 står i forbin-delse med sugekassens forlængelse, som i virkeligheden er et dødt rum, og anvendes kontinuerligt eller periodisk til 25 fjernelse af støv og fibre fra dette rum. En udstrømningsåbning P-8 er anbragt i et bageste hjjørne af sugekassen 715 og medvirker til, at fibrene rammer formningsbåndet 712 under dannelse af en vinkel S -på .2.1-30° med dette.The FIG. 8 illustrates a device 710 similar to that of FIG. 7, including the construction of the distributor 711 and its opening 711a, the forming belt 712 and its direction A, sidewalls 720, and the provision of a sealing roller 718. The suction box 715 is generally trapezoidal and has an inclined rear edge 715e, the upper edge of which is disposed in front of the sealing roll 718. The suction box 715 also has an anteriorly inclined wall 715d, the upper edge of which is located slightly behind the leading edge of the opening 711a, this wall constituting a partition in the box 715. The suction box 715 also has a front = 20 tea extension defined by a vertical wall 715f in combination with the wall 715d as well as an extension parallel to 715c [in the lower wall of the suction box. A cleaning opening C-7 is associated with the extension of the suction box, which is in fact a dead space, and is used continuously or periodically to remove dust and fibers from this space. An outflow opening P-8 is arranged in a rear corner of the suction box 715 and helps the fibers hit the forming band 712 to form an angle S of .2.1-30 ° therewith.

Selv om der ikke er vist tætningsmidler på de bage-30 ste sider af de i fig. 3, 4, 5 og 6 viste formningshoveder, vil en fagmand forstå, at sådanne tætningsorganer kan tilvejebringes som vist i fig. 1, 2, 7 og 8. Valget af egnede konstruktioner .foretages i hvert enkelt tilfælde efter, hvad der samarbejder bedst med apparatet iøvrigt. Tætningsorganer-35 jne i de i fig. 1 og 2 viste udførelsesformer er bladene 17 eller 117 anbragt på den bageste side af fordelingsorganet 11, 111.Although sealants are not shown on the trailing sides of the FIG. 3, 4, 5 and 6, those skilled in the art will appreciate that such sealing means can be provided as shown in FIG. 1, 2, 7 and 8. The choice of suitable structures is made in each case according to what works best with the apparatus. Sealing means in the FIG. 1 and 2, the blades 17 or 117 are arranged on the rear side of the distributor 11, 111.

Claims

An apparatus for making fiber webs comprising a means (11, 11a, 111, 211, 311, 411, 511, 611 or 5,711) for distributing dry fibers, a forming band (12, 112, 212, 312, 412, 512, 612 or 712), a flat section of which is disposed below the distributor and is linearly movable at a predetermined, first speed, and a suction box (15, 115, 215, 315, 415, 515, 615 or 715) 10 below the planar section of the forming belt to draw air through the forming belt at a predetermined second velocity perpendicular to said planar section, characterized by means for communicating a horizontal velocity component less than the first velocity , for the fibers in the direction of motion of the forming belt, which means causes the fibers to hit the forming belt to form an angle of 21-30 ° with this when the second velocity is higher than approx. 1.27 m / sec, and the first speed is higher than approx. 2.54 m / sec.

Apparatus according to claim 1, characterized in that the means for communicating a horizontal velocity competitor comprise a series of uniformly spaced / positioned blades (17) extending "across the plane section, wherein the blades are disposed between the distributor (11) and the planar section and each comprises a section of a hollow circular cylinder arranged such that a tangent to its upper edge is substantially parallel to the flow of air and fibers from and a tangent to its lower edge is substantially parallel to the planar section, wherein the blades (17) cooperate with the suction box (15) to direct the fiber flow from the distributor in the direction of movement of the forming belt (12) to form an acute angle with it. planar sections of this one.

Apparatus according to claim 1, characterized in that the means for communicating a horizontal speed component comprise a series of parallel, mutually spaced guide plates (117) extending over a bottom opening arranged in the distributor (111) in a direction transverse to the direction of movement of the forming band (112), each blade extending obliquely downwards in said direction of movement, forming an angle of 21-30 ° with the forming band.

Apparatus according to claim 1, characterized in that the means for communicating a horizontal velocity component comprises a guide member (215a) extending horizontally over the front area of an upper horizontally located opening (215b) arranged in the suction box (215) below the forming belt (212), wherein the guide member (215a) extends in a direction transverse to the direction of movement of the forming belt and includes a free edge portion facing in the same direction of movement, an imaginary line between an anterior edge of the the distributor (211) and the free edge portion of the guide member extend downwardly in the flow direction to form an angle of 21-30 ° with the forming band (212).

Apparatus according to claim 4, characterized in that the guide means is a plate or lip (215a) which extends in the flow direction and is placed at the top of one of the front sides of the suction box (215) and that the suction box has an opening (P 2) arranged in a front part of the suction box for connection with a suction device.

Apparatus according to claim 4, characterized in that the guide means is an endless band (415c or 515a) having an upwardly facing surface and arranged to move it below the forming band (412, 512), the apparatus further comprising a rotating brush 30 in contact with the lower barrel of said belt.

Apparatus according to claim 6, k characterized in that the endless belt (515a) is arranged to move its upwardly facing surface in a direction transverse to the direction of movement of the forming belt (512).

Apparatus according to claim 6, characterized in that the endless belt is arranged for movement of its upwardly facing surface in the direction of movement of the forming belt (412). o DK 1K5441B n

Apparatus according to claim 1, characterized in that the suction box (315, 715) has an inner guide plate (315a or 715d) spaced from a leading edge of the suction box, an outflow opening (P-3 or P-8) arranged in an area of the suction box behind the guide plate for connection with a suction device, wherein an imaginary line touching an upper edge of the guide plate (315a or 715d) and a leading edge of a lower outlet opening in the distributor (311 or 711) forms an angle of 21-30 ° 10 with the forming band (312, 712), so that the baffle in association with a suction effect supplied to the suction opening (P-2 or P-8) causes the fibers to hit the forming band to form an angle of 21-30 ° with this .

An apparatus for making fiber webs, comprising a fiber distribution means (611, 711) having a bottom, a horizontally located opening (611a, 711a), a forming band (612, 712), a flat section of which is disposed below orifice and is linearly movable at a predetermined first speed, and a suction box below said plane section to draw air through the forming belt with a predetermined second speed component perpendicular to the forming belt, characterized in that the suction box is partially formed by parallel anterior and posterior walls (615d, 615e and 715d) extending transversely of the forming PC's direction of motion and inclined downwardly in said direction of motion to form an angle of 21-30 ° with the horizontal plane at which an upper edge of the front wall (615e, 715e) is spaced posteriorly from the bottom opening (611a, 711a) of the distributor, thereby forming a space extending 30 across the direction of movement of the forming belt; wherein an outflow opening (P-7, P-8) is disposed in a lower region of the suction box near a lower edge of the rear wall (615e, 715e), and a sealing roll (618, 718) extends across the forming belt 35 direction of movement and partially cover said gap.

13 DK: 454-16 0

Apparatus according to claim 10, characterized in that an upper edge of the front wall (615d) is aligned with a front edge of the bottom opening (611a) in the distributor (611).

Apparatus according to claim 10, characterized in that an upper edge of the front wall (715d) is arranged behind a front edge of the bottom opening (711a) of the distributor (711).

A method of producing fiber webs which are substantially free of transverse ripples, characterized in that the fibers are fed in a stream to a flat section of a forming band while moving at a speed of more than 2.54 m / sec. . holding the angle at which said current strikes the plane section is maintained at 21-30 °, 15 and maintaining a pressure drop through the plane section by causing air to flow therethrough at a speed perpendicular to the plane section of more than 1.27 m / sec. 20 25 30 35