Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
  • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
  • D21H23/22—Addition to the formed paper
  • D21H23/24—Addition to the formed paper during paper manufacture
  • D21H23/26—Addition to the formed paper during paper manufacture by selecting point of addition or moisture content of the paper
  • D21H23/28—Addition before the dryer section, e.g. at the wet end or press section
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
  • D21G9/00—Other accessories for paper-making machines
  • D21G9/009—Apparatus for glaze-coating paper webs
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/80—Paper comprising more than one coating
  • D21H19/84—Paper comprising more than one coating on both sides of the substrate
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
  • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
  • D21H23/22—Addition to the formed paper
  • D21H23/24—Addition to the formed paper during paper manufacture
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
  • D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
  • D21H23/22—Addition to the formed paper
  • D21H23/70—Multistep processes; Apparatus for adding one or several substances in portions or in various ways to the paper, not covered by another single group of this main group

Definitions

• the invention relates to a method for applying a liquid or pasty application medium to a running material web - in particular made of paper or cardboard according to the preamble of claim 1 and a paper machine with a device suitable for carrying out the method.
• US Pat. No. 5,152,872 is known from the prior art.
• a one-sided application is carried out directly on the fibrous web by means of a roller applicator in a single-wire wet section.
• the screen wraps around a roller that supports the application process.
• the fibrous web lies on the side of the screen facing away from the rollers.
• the roller applicator touches the fibrous web in the looping area of the supporting roller.
• the roller applicator is a device consisting of three rollers.
• the application roller surface is detached from the web surface, roughening or plucking occurs on the web surface.
• US Pat. No. 5,622,599 is known from the prior art.
• one-sided application is carried out from above directly onto the still wet fibrous web in the wire section of a paper machine by means of spray nozzles.
• the spray application takes place in the area of the straight course of the sieve, in which a sieve ripple can partially form transversely to the direction of the sieve running.
• the spray application can take place irregularly on the material web surface (seen transversely to the direction of wire travel).
• This construction also does not include the order in a twin wire zone.
• an application device in which the application medium is applied to the still wet material web in an area supported by a roller.
• the material web can lie between two sieves or on only one sieve. If the material web surface is covered by a sieve, the application device feeds the application medium to the material web surface, for example through the sieve.
• Another application option is the path to indirect application to the material web. With the help of the applicator, the medium is first applied to the roller surface supporting the screen. Due to the rotation of the roller, the application medium is then fed through the supporting sieve to the surface of the material web.
• This application method is used, for example, if the surface of the material web facing away from the roller is not covered by a sieve.
• the application media can be, for example, coating color, starch or other substances. The full content of the disclosure of the above-mentioned application is included in this application.
• the object of the invention is therefore to find a method and a device in which an improved anchoring of the application medium on the material web is achieved, so that its printability is improved and the technical complexity compared to the previous solutions is reduced as much as possible.
• the medium hooks up with fibers of the material web surface. Since there is still some water inside the material web, the medium does not penetrate into the middle of the material web, but mainly remains in the outer layers. The result is a steep distribution of the medium in the z direction of the paper sheet (i.e. over the flat cross section), which significantly improves printability.
• An applicator is used as the application device in the twin wire zone.
• This is a distribution pipe arranged transversely to the direction of wire travel with a slot nozzle also extending in this direction.
• the medium is pressed out of the slot nozzle by pressure of 0.05 to 0.5 bar, preferably 0.1 to 0.4 bar. Because this applicator is arranged near or in the immediate vicinity of elements supporting the screen surface (for example drainage strips or rollers), a screen ripple extending transversely to the screen running direction is eliminated.
• Such a smoothed screen surface enables the applicator to be positioned very close to the screen surface. It is even a direct one Can be placed on the screen surface.
• the order weight (dry mass of the application medium) is between 1 and 10 g / m 2 per side, depending on the application.
• auxiliaries that have a surface-consolidating effect.
• agents include, for example, starch, surface sizing agents, latex, and
• a main idea of the inventor is to make a residual addition of the auxiliaries in an area of the paper machine in which the material web already has a higher dry content. This leads to a higher retention of the auxiliary substances in the
• This combination of the split order can also save an additional size press or a coating machine.
• Another idea of the inventor is the application of fine fibers in the twin-wire zone of the wet part. This also achieves a surface consolidation of the material web. The fine fibers are unwantedly washed out during dewatering - predominantly from the surface of the material web. By recycling the fine fibers, they become the layer in the
• Figure 1 Partial view of a paper or board machine with exemplary locations of the
• FIG. 2a Detail from a twin wire zone of a wet end (further embodiment);
• Figure 3 Section of a single-tier dryer group
• Figure 4 Section of a two-tier dryer group.
• a deflection device F for example a forming roller
• the screens run towards one another in a wedge shape and the fiber suspension is subsequently enclosed between the screens.
• a first dewatering of the fiber suspension already takes place here and a fiber mat 38 (material web) is formed.
• the twin-wire zone begins at the deflecting device F and ends at the roller S, for example a wire suction roller.
• Further drainage elements 7, 8 and 9 can also be located in the twin-wire zone.
• the drainage element 7 can be a drainage box with fixed drainage strips.
• the drainage box 7 are then generally compliant, compressible
• Drainage strips 9 arranged opposite one another.
• the drainage element 8 can be a so-called screen suction box, for example.
• the area of the twin-wire zone can also have a curved course.
• an application medium can be introduced into the already partially dewatered material web 38 through the screens into the fiber structure of the material web.
• This application medium can contain coating color, starch, surface-consolidating media or fiber fine suspensions.
• the applicators 5 and 10 are preferably arranged in the vicinity of elements S, 7, 8 and 9 touching and thus supporting the screen webs 3 and 4.
• the sieves By supporting the sieves, one that is possibly transverse to the direction of the sieve run becomes
• the design of the applicators 5 and 10 is known from the prior art. They consist of a pressure chamber with the application medium, which has a slot-shaped opening in the application direction.
• the material web 38 After the first application of an application medium in the wet section 33, the material web 38 is fed to the press section 34 via the wire 4.
• An endless belt 12 transfers the material web 38 to the press section 34.
• Another - not shown here - Transfer device (for example a blowing device) guides the material web 38 either in the course shown as a solid line or as a dashed line through a first press 13. Now the material web 38 has a dry matter content which permits a further application of a medium which solidifies the web surface.
• the application devices 14, 16 and 17 of the press section 34 and also the subsequent application devices in the dryer section can be directed directly onto the web surface, since the material web 38 here may already have sufficient tensile strength and not must be constantly supported by felts and therefore not covered by felts or later drying fabrics.
• the application devices can, in addition to the applicators already mentioned, also be spray nozzles arranged in a row transversely to the wire running direction.
• the second application medium can be applied to the surface of the press roll by means of an application device. The medium is then transferred to the material web surface by the rotation of the press rolls.
• the material web 38 is also not shown by means of a Transfer device forwarded around the paper guide roller 37 to the dryer section 35.
• the drying cylinders 18, 19, 20, the drying wire 27 and the drying wire suction rolls 26 represent a single-row felted drying group.
• the area where the material web 38 lies open on the drying cylinder 18 - that is, it is not covered by the drying wire 27 - is a suitable place to arrange an application device 36, because here the material web is supported by the drying cylinder 18.
• the single-row dryer group there is only once the opportunity to carry out an order directly on the side of the material web 38 facing away from the drying cylinder. This is usually possible at the beginning or at the end.
• Dryer screen suction roller 26 the material web 38 lies on the outside of the dryer fabric 27 and is supported by the roller body. This position is also suitable for attaching a further application device 25 in order to apply surface-strengthening media to the web surface.
• the drying cylinders 21, 22, 23, 24, and the drying fabrics 29, 30, show a two-row drying group, shown in part. Here you can
• Arrange application devices 28, 31 and 32 in such a way between an upper and a lower drying cylinder that both surfaces of the material web are repeatedly treated alternately with application media can.
• the application devices can be used both in the start or end area of the drying group, in which the material web still rests on the drying cylinder and is therefore supported, as well as in the area where the material web is located in the transition between two drying cylinders, i.e. in the area of the free moves.
• FIG. 2 shows a twin-wire zone of a wet part that differs from FIG. 1.
• the material web 38 lies between the upper sieve 39 and the lower sieve 40.
• the arrow 41 indicates the running direction.
• the web of material is mutually dewatered by the drainage elements 42 and 43, which are only shown as examples.
• On the circumference of a first roller for example a forming roller FW
• a first applicator 44 with its slit-shaped nozzle 45.
• a second roller here a wire suction roller SSW Double screen area another applicator 46 may be arranged.
• FIG. 2a Another embodiment of a twin-wire zone of a wet part is shown in FIG. 2a.
• the double sieve consisting of the upper sieve 39 and the lower sieve 40, which carries the resulting paper web 38 between them, can be seen.
• the paper web 38 is in contrast to FIG. 2, in which it is not shown separately for better identification of the top and bottom sieves, shown in dashed lines.
• the two screens run over the first screen suction roll SSW1, one on the underside
• Application device 44 is arranged, which applies a medium to the underside of the paper web 38.
• the twin wire is then passed to the second wire suction roll SSW2, which is wrapped by the side of the lower wire, a second application device 46 being arranged on the side of the upper wire 39, which applies a second medium to the top of the material web 38.
• the twin wire is brought up to a subsequent deflecting roller which lifts the top wire 39 from the material web, after which the resulting paper web 38 is carried further lying on the lower wire 40.
• FIG. 3 shows an enlarged detail of the single-tier dryer group from FIG. 1.
• the material web 38 moves to the drying cylinder 18 after the paper guide roller 37 has been wrapped.
• the dryer fabric guide roller 49 is arranged so high that one side of the web lies freely on the cylinder surface. Sufficient space has thus been created that an application device 36 can be assigned to the web surface. For possible contamination on the part of the application device 36 to fix the surface of the drying cylinder 18, this is assigned a cleaning scraper 47.
• the application device 25 and possibly another application device 48 act on the surface of the material web 38 facing the cylinder surface.
• the lower dryer fabric 30 and an associated dryer fabric guide roller 50 of the subsequent two-row dryer group can already be seen.
• FIG. 4 shows an enlarged detail of the two-row dryer group from FIG. 1.
• the material web 38 comes from the single-row dryer group and initially wraps around the drying cylinder 21.
• the drying wire guide roller 51 is arranged high enough that the material web 38 lies partially open on the cylinder surface of the drying cylinder.
• An application device 28, which manages the application of the second medium, is the open area supported by the drying cylinder 22
• the application devices 52 and 53 can also be used.
• the Application device 31 is assigned an application device 53 opposite.
• Headbox screen guide roller screen screen application device (applicator) paper machine foundation dewatering element (dewatering box) dewatering element (screen suction box) dewatering element (dewatering ledges) application device (applicator) wire guide roller endless belt first press application device (applicator) application device (press) application device (applicator) application device (applicator) drying cylinder drying cylinder drying cylinder Drying cylinder drying cylinder drying cylinder Applicator means (applicator) sendsiebsaugwalze dryer fabric application device (applicator) drying drying application device (applicator) application device (applicator) wet section press section drying section of application device (applicator) paper roll web upper sieve bottom wire running direction dewatering element dewatering element application device (applicator) slot-shaped nozzle application device (applicator) cleaning blade applicator (applicator)fersiebleitwalze Drying wire guide roller Drying wire guide roller Application device (applicator) Application device (applicator) F deflection device (forming roller)

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• Paper (AREA)
• Coating Apparatus (AREA)

Applications Claiming Priority (7)

Publications (2)

Family

ID=27218355

Family Applications (1)

Country Status (7)

Families Citing this family (13)

Family Cites Families (17)

• 1998
  • 1998-10-22 WO PCT/DE1998/003096 patent/WO1999022067A1/fr not_active Ceased
  • 1998-10-22 EP EP98961031A patent/EP0948678B1/fr not_active Expired - Lifetime
  • 1998-10-22 JP JP52298999A patent/JP2001507090A/ja not_active Ceased
  • 1998-10-22 US US09/331,173 patent/US6383337B1/en not_active Expired - Fee Related
  • 1998-10-22 BR BR9806717-6A patent/BR9806717A/pt not_active IP Right Cessation
  • 1998-10-22 AT AT98961031T patent/ATE284467T1/de active
  • 1998-10-22 CA CA002275993A patent/CA2275993A1/fr not_active Abandoned

Non-Patent Citations (1)

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