Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
  • D21G1/00—Calenders; Smoothing apparatus
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F11/00—Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines
  • D21F11/02—Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines of the Fourdrinier type
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F5/00—Dryer section of machines for making continuous webs of paper
  • D21F5/02—Drying on cylinders
  • D21F5/04—Drying on cylinders on two or more drying cylinders
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F5/00—Dryer section of machines for making continuous webs of paper
  • D21F5/18—Drying webs by hot air
  • D21F5/181—Drying webs by hot air on Yankee cylinder
• • 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
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
  • D21G1/00—Calenders; Smoothing apparatus
  • D21G1/006—Calenders; Smoothing apparatus with extended nips

Definitions

• the invention relates to a machine for producing a fibrous web, in particular a paper or board web, with a headbox, a forming unit, a press section, a pre-dryer section, a MG smoothing and / or Yankee cylinder, a smoothing device, a coater and a reel. It also relates to a method for producing a fibrous web, in particular paper or board web, in particular using a machine of the type mentioned, in particular for the production of single-side coated special paper.
• the paper web is guided after the press section over a large, steam-heated cylinder, a so-called MG-smoothing or Yankee cylinder.
• a so-called MG-smoothing or Yankee cylinder serves on the one hand to dry the paper web.
• the paper web is smoothed on its side facing the MG smoothing or Yankee cylinder by the long contact with the smooth and hot surface of the MG smoothing or Yankee cylinder.
• MG machine glazed
• One-side coated special papers (C1 S) are currently produced on such machine tools. These machines have only a Glättzylinder (GZ) to dry the fibrous web.
• the production capacity or speed of these machines is limited by the size or dry capacity of the Yankee.
• the maximum raw paper capacity is about 35 t / m, d for a Yankee cylinder with a diameter of 6 m and a gas-heated hood and a raw paper weight of 30-60 g / m 2 .
• d is aimed for a pre-drying section in front of the Yankee cylinder and a Yankee cylinder with the largest possible diameter needed.
• the Yankee cylinder is overhead, ie in contact with the lower side of the track.
• SpeedSizer is usually the precoat applied to the smooth bottom and strength on the back. The order of the
• Top coat is done with a so-called BladeCoater, and the curl control with a so-called LAS (Liquid Application System), ie a special application unit with associated roller or a nozzle moistener for wetting the web.
• Calendering is also carried out online with two to four or more soft- ners with a line force of up to 350 N / mm using thermo rolls with a surface temperature in the range of 150 ° to 200 ° on the underside.
• a currently used high-performance machine is designed for raw paper with a basis weight of 28 - 40 g / m 2 for a speed of 1200 m / min.
• Such a machine includes a hydraulic headbox with dilution water technology, a wire with a hybrid former and a shaker, one
• DuoCentri NipcoFlex press with three press nips at least one of which is intended as a shoe press nip, or a tandem NipcoFlex press with two web press nipples arranged one behind the other in the web running direction, a one and / or two row pre-dryer section, a smoothing cylinder with a diameter of 6.4 m, a post-dryer section with a variable number of double-row dryer cylinders, a film press, a BladeCoater and a soft calender with a five-roll stack and four nips.
• a disadvantage of these hitherto conventional high-performance machine tools is the one-sided drying of the web in the pre-dryer section on the Yankee side, which results in a moisture gradient of the web with higher dry content on the side of the web which is pressed against the Yankee cylinder. For optimum gloss and smoothness results, however, the moisture on the Yankee side should be as high as possible.
• Another disadvantage of such a conventional MG machine is the application of the web to the Yankee cylinder with a conventional press roll.
• the MG cylinder is operated with different vapor pressure depending on basis weight and production.
• the line force of the press nip against the MG cylinder can vary within a wide range depending on the quality requirements.
• the different deformation behavior of the smoothing cylinder jacket can not be adequately followed by a conventional pressure roller and even a steel jacket deflection roll, resulting in a different line force progression across the width and uneven quality properties, particularly thickness, smoothness and gloss over the web width.
• the invention has for its object to provide a machine and a method of the type mentioned, in which the aforementioned disadvantages are eliminated and the most efficient production of high quality papers, especially one-side coated special papers allow.
• the inventive machine for producing the fibrous web comprises a headbox, a forming unit, a press section, a pre-drying section, a MG smoothing and / or Yankee cylinder, a coater, a smoothing device and a winding.
• the machine comprises a calender unit with a multi-roll softnip calender with at least one elastic nip and / or a shoe calender with a smooth press cover. Due to the design according to the invention, the machine is particularly suitable for the online production of single-side coated specialty papers (C1 S), while ensuring efficient production of high-quality papers.
• the multi-roll soft-nip calender preferably comprises an elastic nip formed between a soft roll and a hard roll, the softwalt being preferably arranged on the side of the fibrous web facing away from the MG-smoothing and / or Yankee cylinder.
• the shoe calender preferably comprises a shoe press roll having the smooth press cover and a heated counter roll, wherein the shoe press roll is preferably arranged on the side of the fibrous web facing away from the MG smoothing and / or Yankee cylinder.
• the shoe length of such a shoe calender in particular in a range of 60 mm to 160 mm and its line force in particular in one
• the temperature of the surface of the heated mating roll can be in particular in a range of 160 ° C to 250 ° C.
• the moisture of the fibrous web at the inlet into the shoe calender can be in particular in a range between 5% and 7%. In certain cases, it may be sufficient if the calender unit comprises only one shoe calender.
• the calender unit preferably comprises a multi-roll soft-nip calender with at least one and a maximum of four roll nips and / or a shoe calender.
• a smoothing and compression of the web is achieved by means of high compressive stresses in the roll nip, whereby the micro-roughness or Bekk smoothness is correspondingly improved.
• the macro roughness or PPS roughness is improved.
• a multi-roll softnip calender having only one roll nip may comprise, for example, a two-roll stack and a four-nip multi-roll softnip calender, for example, a five-roll stack or two three-roll stacks.
• the shoe calender can be arranged in the web running direction before or after the roll nips.
• the multi-roll softnip calender comprises a soft-iron calender with a stack of three rolls and two nips.
• the pre-drying section comprises a drying group with vertically successive, in particular steam-heated drying cylinders for drying the web side of the fibrous web remote from the MG smoothing and / or Yankee cylinder.
• the drying group With the drying group with successive, in particular steam-heated drying cylinders in the vertical direction, a change of the drying from the underside to the top and a displacement, that is a change in the drying direction, occur. Increasing the moisture gradient on the underside of the fibrous web. Optimum gloss and smoothness values thus result on this side of the web, while smoothing of the back of the web is at least substantially avoided.
• the drying group preferably comprises two to four drying cylinders with successive drying cylinders in the vertical direction.
• the pre-drying section additionally comprises at least one single-row drying group. In the pre-drying section thus a completely closed web guide is maintained.
• the diameter of the MG smoothing and / or Yankee cylinder is advantageously greater than 6 m, in particular greater than 6.6 m and preferably greater than 7 m.
• the cylinder diameter can be 7.3 m, for example.
• the MG smoothing and / or Yankee cylinder can be assigned at least one, in particular gas, preferably steam-heated hood, in particular high-performance hood.
• Such a smoothing and / or Yankee cylinder ensures a high drying capacity and high production.
• the fibrous web is guided, starting from the end of the press section to the MG smoothing and / or Yankee cylinder supported by the machine, resulting in a correspondingly reduced risk of tearing the fibrous web.
• the headbox expediently comprises a hydraulic headbox with dilution water technology, with which first-class basis weight profiles can be achieved.
• the headbox can be provided transversely to the web running direction, for example with a pitch ⁇ 50 mm.
• the forming unit preferably comprises a wire with a hybrid former and preferably a screen shaker, whereby a good formation as well as a lower tenacity ratio l / q and thus a high dimensional stability or low wet transverse elongation are achieved.
• the press section comprises at least one shoe press, preferably a Single NipcoFlex press with only one Schuhpressnip, a DuoCentri NipcoFlex press with two roll nips and a shoe press nip or a Tandem NipcoFlex press with two in the web running direction successively arranged Schuhpressnips, with a high dry solids content and a high initial wet strength are achieved and it is ensured that there is no or at most a minimal open draw.
• a shoe press preferably a Single NipcoFlex press with only one Schuhpressnip, a DuoCentri NipcoFlex press with two roll nips and a shoe press nip or a Tandem NipcoFlex press with two in the web running direction successively arranged Schuhpressnips, with a high dry solids content and a high initial wet strength are achieved and it is ensured that there is no or at most a minimal open draw.
• the transfer of the fibrous web to the MG smoothing and / or Yankee cylinder takes place, in particular, in the region of a pressure roller resting against the MG smoothing and / or Yankee cylinder, preferably a shoe press roll or a deflection compensating roll with an elast jacket which is, for example, a So-called NipcoFullFlex roller, ie a deflection roll can act with a FullFlex sheath, which represents a composite sheath that is much more flexible than a steel or cast iron jacket and the contour of the MG Smooth Yankee cylinder can follow better.
• the press cover is much more flexible than a steel or cast iron jacket and can follow the contour of the MG cylinder better.
• a NipcoFullFlex roll stands out from a shoe roll, among other things, in that no concave shoe is used as a support source, but several along the length of the roll (or width of the machine) closely spaced, adjacent convex support sources.
• the jacket is composed of a CFRP jacket with an outer coating of polyurethane. Such a jacket is more flexible than a steel or cast shell, so that it can better adapt to a changing contour of the mating element, such as, for example, the MG smoothing Yankee cylinder.
• the smoothing device comprises a pre-calender, in particular a soft-smoothing unit with a stack comprising two rollers, a hard nip or a belt calender.
• a Softglätttechnik especially a uniform compression and thickness calibration is achieved.
• the machine comprises a film press for a surface treatment of the fibrous web.
• a film press for a surface treatment of the fibrous web.
• the machine includes a BladeCoater for non-contact application of a top coat to the fibrous web.
• a top coat with profiling is possible.
• With such a blade Coaters are guaranteed in particular a uniform order and a good smoothness.
• the machine also includes one or more cooling cylinders with associated steam box for curl control.
• one or more cooling cylinders with associated steam box for curl control.
• the press section comprises a DuoCentri-NipcoFlex press with two roll nips and a shoe press nip against a central roll, a NipcoFlex press with only one shoe nip and especially upper felt and lower transfer belt or double weft or a tandem NipcoFlex press with two consecutive shoe pressings .
• the press section can also comprise a so-called NipcoFullFlex roller with a press roll having a composite jacket.
• the composite shell of such a NipcoFullFlex roller is significantly harder than conventional polyamide sheaths.
• the wear layer is wear-resistant and temperature-resistant.
• the MG smoothing and / or Yankee cylinder is in contact with either the lower or the upper side of the fibrous web.
• the MG smoothing and / or Yankee cylinder is provided at the top or bottom.
• the successively drying cylinders of the preceding preceding drying group preferably contact the upper side of the fibrous web, while MG smoothing and / or contacting the upper side of the fibrous web Yankee cylinder the vertically successive drying cylinder of the preceding preceding drying group prefers the bottom Contact fibrous web.
• at least one single-row dryer group may be provided in front of it.
• the MG smoothing and / or Yankee cylinder is preferably associated with at least one, in particular gas, preferably steam-heated hood.
• a after-dryer section with at least one single- and / or double-row drying group can advantageously be provided.
• the machine comprises a water film application device and / or a nozzle moistener with a subsequent drying group.
• the inventive method for producing a fibrous web, in particular paper or board web is provided in particular for the production of single-side coated special papers, wherein it can be carried out in particular using a machine according to the invention.
• a pulp suspension supplied by means of a headbox is dewatered in a forming unit to form a fibrous web, the fibrous web further dewatered in a press section, pre-dried in a pre-drying, smoothed in a MG smoothing and / or Yankee cylinder and a smoothing device, painted in a coater and wrapped in a reel.
• the fibrous web is calendered by means of a calender unit having a multi-roll soft-nip calender with at least one elastic nip and / or a shoe calender with a smooth press cover.
• the fibrous web is fed to the drying group with vertically successive drying cylinders having a solids content in the range of 45% to 55%.
• the fibrous web is led out with a dry content in the range of 50% to 60% from the dryer group with successive drying cylinders in the vertical direction.
• the steam-heated drying cylinders of the drying group with the successive drying cylinders in the vertical direction are preferably each operated with a vapor pressure in the range from 2.0 bar to 6.0 bar.
• the fibrous web or paper or board web is preferably produced with a raw paper weight in the range from 20 g / m 2 to 120 g / m 2 .
• a one-sided line in the range of 5 g / m 2 to 30 g / m 2 is applied to the MG-smoothing and / or Yankee cylinder side facing the fibrous web.
• the fibrous web or paper or board web is advantageously produced with a finished paper weight in the range from 20 g / m 2 to 150 g / m 2 and in particular in the range from 30 g / m 2 to 90 g / m 2 .
• the fibrous web or paper or board web is produced with a maximum paper machine speed in the range of 1500 m / min.
• the fibrous web is produced with a breaking length ratio ⁇ 2.0: 1, in particular ⁇ 1, 6: 1 and preferably ⁇ 1, 5: 1. It is also advantageous if the fibrous web to be produced is passed through the production machine at least to a dry content in the range of 60% in a closed train. Preferably, the fibrous web is generated with a roughness value ⁇ 0.6 ⁇ on the coated side.
• FIG. 1 a) and 1 b) is a schematic representation of an exemplary embodiment of a machine according to the invention for producing a fibrous web.
• FIG. 2 shows a schematic partial representation of an exemplary embodiment of the machine according to the invention without a drying group with drying cylinders successive in the vertical direction compared with the machine according to FIGS. 1 a) and 1 b)
• Fig. 3 is a partial schematic representation of a relative to the machine of FIG. 2 modified another exemplary embodiment of the machine according to the invention.
• 1 to 3 show different exemplary embodiments of a machine 10 according to the invention for producing a fibrous web 12, in particular paper or board web.
• the machine 10 can be provided in particular for producing single-side coated special papers (C1 S).
• the machine 10 comprises in each case a headbox 14, a forming unit 16, a press section 18, a pre-drying section 20, a MG smoothing and / or Yankee cylinder 22, a smoothing device 24, a coater 26 and a winding 28.
• the pre-drying section 20 comprises a drying group 30 with vertically successive, in particular steam-heated, drying cylinders 30 ', 30 "for drying the MG smoothing and / or Yankee cylinders 22 opposite web side of the fiber web 12th
• the drying group 30 with successive drying cylinders in the vertical direction can in particular comprise two to four drying cylinders, wherein in the present case it has, for example, two such drying cylinders 30 ', 30 ".
• the pre-drying section 20 can comprise at least one single-row drying group 32 arranged in the web running direction L in front of the drying group 30 with vertically successive drying cylinders 30 ', 30 " it is in particular greater than 6.6 m and preferably greater than 7 m.
• the fibrous web 12 is guided from the end of the press section 18 to the MG smoothing and / or Yankee cylinder 22 supported by the machine 10.
• the headbox 14 may in particular comprise a hydraulic headbox with dilution water technology. It can be provided transversely to the web running direction L with a pitch of in particular ⁇ 50 mm.
• the forming unit 16 can, as shown, a fourdrinier wire 34 with a hybrid former 36 and preferably a Sieb thoroughlyelung include, in the present case, a shaking of a breast roll 38 is provided.
• the press section 18 can comprise at least one shoe press 40, preferably a single NipcoFlex press with only one shoe press nip, a DuoCentri NipcoFlex press with two roll nips and a shoe press nip or a tandem
• NipcoFlex press with two in the web running direction L successively arranged shoe press nips.
• the transfer of the fibrous web 12 to the MG smoothing and / or Yankee cylinder 22 can take place in the region of a pressure roller 42 resting against the MG smoothing and / or Yankee cylinder 22, in particular a shoe press roll or a deflection compensating roll with an elast jacket.
• the smoothing device 24 may comprise a pre-calender, in particular a soft smoothing system with a stack comprising two rolls, a hard nip or a belt calender.
• a film press 44 may be provided for a surface treatment of the fibrous web 12.
• the coater 26 may include a BladeCoater for applying a topcoat to the fibrous web 12.
• a BladeCoater for applying a topcoat to the fibrous web 12.
• one or more cooling cylinders 46 may be provided with associated steam blower box 48.
• the machine 10 has a calender unit 50, which may in particular comprise a multi-roll soft-nip calender 52 with at least one elastic nip and / or a shoe calender 45 with a smooth press jacket.
• the multi-roll soft-nip calender 52 may include a soft-ware with a three-roll, two-nip stack.
• the press section 18 may, for example, a DuoCentri-NipcoFlex press with two roll nips and a shoe press nip against a central roll or a NipcoFlex press with only one Schuhpressnip and especially upper felt and lower transfer belt or double Befilzung or a tandem NipcoFlex press with two in the web running direction one behind the other arranged shoe press nips include.
• a press section 18 with a NipcoFullFlex roller with a press roll having a composite jacket is also conceivable.
• the MG smoothing and / or Yankee cylinder 22 is in contact, for example, with the lower side of the fibrous web 12, the MG smoothing and / or Yankee cylinder 22 being arranged on the upper side or the fibrous web 12 pointing upwards to the MG web. Smoothing and / or Yankee cylinder 22 is performed.
• the drying cylinders 30 ', 30 "of the drying group 30 following one another in the vertical direction contact the upper side of the fibrous web 12 in the present case.
• the MG smoothing and / or Yankee cylinder 22 may be associated with at least one gas-heated, in particular steam-heated, hood 56.
• a drying section 58 with at least one single- and / or double-row drying group can be provided.
• a water film applicator and / or a nozzle moistener with a downstream drying group can be provided.
• the particular provided as a shoe press roll or deflection compensating roll with an elastomeric jacket pressure roller 42 is disposed within the loop of a transfer belt or press felt 60 through which the fibrous web in the machine 10 as shown in FIGS. 1 a) and 1 b) of the fibrous web over the vertical direction successive drying cylinder 30 ', 30 "of the drying group 30 leading fabric or dryer fabric 62 is adopted.
• FIG. 2 shows a part of an exemplary embodiment of the inventive machine 10 without a drying group with successive drying cylinders in the vertical direction compared to the machine according to FIGS. 1 a) and 1 b), in which the fibrous web 12 is from a further transfer belt 64, which is the fibrous web 12 is supplied from the single-row dryer group 32, to which in its loop the pressure roller 42 containing transfer belt or press felt 60 is passed.
• the machine according to FIG. 2 can at least essentially be designed again like the machine illustrated in FIGS. 1 a) and 1 b).
• the further exemplary embodiment of a machine 10 according to the invention which is only partly shown in FIG. 3 differs from that according to FIG. 2 at least substantially only in that the fibrous web 12 is transferred directly from the transfer belt 60 containing the pressure roller 42 in its loop Last drying cylinder 66 of the preceding single-tier dryer group 30 is removed.

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• 2017
  • 2017-08-10 DE DE102017118222.5A patent/DE102017118222A1/de active Pending
• 2018
  • 2018-06-08 WO PCT/EP2018/065105 patent/WO2019029863A1/de unknown
  • 2018-06-08 CN CN201880051885.4A patent/CN110998021B/zh active Active
  • 2018-06-08 EP EP18729960.7A patent/EP3665325A1/de active Pending

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