Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F9/00—Complete machines for making continuous webs of paper
  • D21F9/003—Complete machines for making continuous webs of paper of the twin-wire type
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
  • D21F3/04—Arrangements thereof
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F3/00—Press section of machines for making continuous webs of paper
  • D21F3/02—Wet presses
  • D21F3/04—Arrangements thereof
  • D21F3/045—Arrangements thereof including at least one extended press nip
• • 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
  • D21F5/042—Drying on cylinders on two or more drying cylinders in combination with suction or blowing devices
  • D21F5/044—Drying on cylinders on two or more drying cylinders in combination with suction or blowing devices using air hoods over the 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
  • D21F5/182—Drying webs by hot air through perforated cylinders
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F7/00—Other details of machines for making continuous webs of paper
  • D21F7/08—Felts
  • D21F7/12—Drying

Definitions

• This invention relates to a machine for producing and / or refining a fibrous web, in particular paper according to the preamble of patent claim 1 and a method for producing fibrous webs.
• Wood-containing and wood-free fibrous materials are increasingly manufactured today with increasing web speeds. As a result, the load on the moist fibrous web increases.
• the content of the added fillers is increasingly increased in the production, with the result that the strength of the wet fibrous web decreases accordingly.
• the object of the invention is to propose a machine with improved runability for the production and / or further processing of fibrous webs with increased filler content at elevated web speeds, which is also cost-effective and space-saving. It is also the object of the invention to propose improved processes for the production of fibrous webs with increased filler content at elevated web speeds.
• the object is achieved by a machine according to claim 1 and by a method according to claim 19.
• the machine according to the invention for the production and / or further processing of a fibrous web has a press section and a dryer section, wherein the press section comprises only one press nip and at least the first and / or second dryer section of the dryer section comprises an air dryer.
• the fibrous web in the press section does not have to be transferred from one covering to another covering.
• An air dryer has a significantly higher drying capacity than conventional heated dryer cylinders.
• the dry content of the fibrous web is increased already at the beginning of the dryer section so that it is sufficiently strong and tear-proof, whereby the runability is also significantly increased.
• the press section with only one press nip is significantly more compact than conventional press sections with multiple press nips.
• the drying section with an air-flow drying unit at least in the first and / or second drying group is significantly more compact executable with the same drying performance than conventional dryer groups with heated drying cylinders. Accordingly, the machine according to the invention is designed significantly more compact than known machines for the production and / or further processing of fibrous webs.
• the fibrous web is dewatered in the former to a dry content of at least 18%, more preferably to a dry content of at least 20%.
• the machine according to the invention is preferably used for the production of fibrous webs with basis weights in the range between 35 g / m 2 and 120 g / m 2 and filler contents between 10% and 40% with web speeds up to 2400 m / min and more.
• Drying performance can be significantly increased if the first and second dryer sections of the dryer section include airflow dry ice. As a result, the runability is further increased. Furthermore, the spatial extent of the dryer section can be significantly reduced, so that the machine becomes more compact for the production and / or further processing of a fibrous web.
• At least one air-flow drying unit of the invention works according to the principle of für für Stromtrockung or TAD drying called.
• At least one air-flow drying unit operates according to the principle of impingement drying or impingement drying.
• a preferred embodiment of the invention provides that the fibrous web is not covered on the directed to the incoming air side with a string.
• the fibrous web is preferably guided through the two air-flow drying units in such a way that one side of the fibrous web is impinged with air in an air-flow drying unit and air is impinged on the other side of the fibrous web in the subsequent other air-flow drying unit , Due to the symmetrical treatment of the fibrous web in the dryer section, a symmetrical structure of the fibrous web, i. supports the same properties of the fibrous web on both sides.
• a further advantageous embodiment of the invention provides that the machine has a plurality of pairs of air flow drying units, wherein in the first air flow drying unit of the pair one side of the fibrous web is supplied with air and wherein in the subsequent second air flow drying unit of the pair, the other side of the fibrous web with Air is flown.
• each pair treated the fibrous web symmetrical - is on the one hand, a symmetrical structure of the fibrous web, i. supports the same properties of the fibrous web on both sides.
• the fibrous web to be dried partially wraps around the heated drying cylinders in a conventional drying group.
• a drying cylinder with a diameter of 3 meters or more, preferably 4 meters or more, ie the respective drying group is formed by only one such drying cylinder.
• the drying cylinder of the air flow drying device has a drilled lateral surface which can be vacuumed.
• the fibrous web is guided on a covering over the drying cylinder, wherein on the paper side of the covering a negative pressure, mediated over the drilled lateral surface of the evacuated drying cylinder.
• the air flow in the air-flow drying unit is produced by a hood surrounding the drying cylinder in the looping region of the fibrous web at least in sections, between which and the drying cylinder the fibrous web is guided.
• a compromise between good drying performance and reasonable stress on the fibrous web through the air flow drying unit leading stringing is achieved when the heated air in the air flow drying unit at a temperature of 15O 0 C or more, preferably from 18O 0 C or more, and more preferably from 22O 0 C or has more.
• the shoe press has a shoe length of 270 mm or more, preferably 300 mm or more, and more preferably 330 mm or more.
• a symmetrical drainage of the fibrous web is a prerequisite for a sym metric structure of the sheet properties and thus for good performance properties such as printability, print quality and dimensional stability.
• a further embodiment of the invention provides that the fibrous web is guided in a sandwich between an upper and a lower felt through the one press nip.
• the upper and / or lower felt has a length of 20 meters or more, preferably 30 meters or more.
• the life of the felts is increased because each area of a long felt, in contrast to short felts with the same production capacity has fewer passes through the press nip.
• the dewatering in the press section comprising only one press nip is particularly effective when at least one of the felts used has sufficient capacity to absorb the squeezed out water.
• a further preferred embodiment of the invention therefore provides that the upper and / or the lower felt has a weight per unit area of 1200 g / m 2 or more, preferably of 1500 g / m 2 or more.
• the machine for producing a fibrous web comprises a forming section with a gap former, which preferably dewaters substantially symmetrically.
• a symmetrical dewatering of the fibrous web is a prerequisite for a symmetrical structure of the sheet properties and thus for good performance characteristics such as printability, print quality and dimensional stability.
• the best properties are achieved when the fibrous web in all major sections, i. is treated symmetrically in the Formierpartie, the press section and the dryer section.
• a further particularly preferred embodiment of the invention provides that the fibrous web is guided without free draw from the forming section to the end of the second dryer section of the dryer section.
• the one nip press makes it necessary to monitor the condition of the felts and the web as accurately as possible, therefore, all amounts of water, for example. From gutters, tubs measured and recorded as a function of place and time. Likewise, the condition of the felts and web is measured and recorded by continuously traversing sensors. This is a prerequisite to optimize the life of the felts and the operation of the machine.
• the invention relates to a method for producing a fibrous web in which a fibrous web is pressed only once and is treated in the dryer section with air flow.
• the inventive method is used for the production of
• Fibrous webs with a basis weight in the range between 35g / m 2 and 120g / m 2 and a filler content between 10% and 40% and for production with a web speed up to 2400m / min and more. This preferably takes place the machine described above use.
• the inventive method is particularly preferably used for the production of fibrous webs having a basis weight between 35g / m 2 and 50g / m 2 and a filler content of between 10% and 25%, preferably between 15% and 18% with a web speed of 1600 m / min or more , preferably 2200m / min or more, and more preferably 2400m / min or more.
• the inventive method is preferably used for the production of fibrous webs having a basis weight between 50g / m 2 and 60g / m 2 and a filler content between 20% and 40%, preferably between 25% and 40% and with a web speed of 1600m / min or more, preferably 2000m / min or more and more preferably 2200m / min or more.
• the inventive method is preferably used for the production of fibrous webs having a basis weight between 60g / m 2 and 120g / m 2 and a filler content between 15% and 25%, preferably between 18% and 25% and with a web speed of 1500m / min or more, preferably 1900m / min or more and more preferably 2100m / min or more.
• Fig. 1 shows a detail of a machine according to the invention for producing a fibrous web in side view.
• the illustrated embodiment of a machine 1 according to the invention for producing a fibrous web has a forming section 2, a press section 3 and a dryer section 4.
• a Fasestoffbahn 5 is introduced in a gap former 6 through a headbox 7 in a gap formed from a top wire 8 and a bottom wire 9 and, for example, dewatered symmetrically to a dry content of 18%, 20% or more.
• the fibrous web 5 is transferred to a pick-up roller 10 from the lower wire 9 on an upper press felt 11 of the press section 3.
• a pick-up roller 10 When transferring between Formierpartie 2 and press section 3 no free train on the fibrous web 5, since this is constantly supported by a fabric 9, 11.
• the fibrous web 5 In the press section 3, the fibrous web 5 is guided in sandwich between the upper press felt 11 and a lower press felt 12 by only one press nip 13 formed by a shoe press 14 and thereby dewatered symmetrically.
• the upper felt 11 and the lower felt 12 have a basis weight of 1200 g / m 2 or more, preferably 1500 g / m 2 or more.
• the shoe press 14 in this case forms a press nip 13 with a length of 270 mm or more, preferably 300 mm or more and particularly preferably 330 mm or more.
• the fibrous web 5 is transferred to a pick-up roller 15 from the lower felt 13 onto a transfer belt 16.
• the drying section 4 has as first and second drying group two successively arranged air flow drying devices 19 and 20 and as a third drying group a conventional drying device 21 with heated
• the air drying device 19 is essentially formed by a drying cylinder 17, a hood 24 and a drying wire 25.
• the fibrous web 5 is guided in the air-flow drying device 19 as far as a roller 26 in a sandwich between the transfer belt 16 and the drying wire 25.
• the fibrous web is guided with one side on the dryer fabric 25 resting and with the other side freely between the drying cylinder 17 and the hood 24, which the drying cylinder 17 in the looping region of the fibrous web
• the air flow of the air flow drying unit 19 is generated by the hood 24.
• the air-flow drying unit 19 operates on the principle of impingement drying or impingement drying called.
• the drying performance in the air-stream drying unit 19 is increased since the fibrous web 5 to be dried is exposed directly to the incoming air.
• the drying cylinder 17 of the air-flow drying unit 19 has a drilled lateral surface. In the interior of the drying cylinder 17 there is a negative pressure, whereby the fibrous web is sucked over the air-permeable dryer fabric 25 in the wrap around to the drying cylinder 17.
• the drying cylinder 17 has a diameter of 4 meters.
• the fibrous web 5 After passing through the air-flow drying unit 19, the fibrous web 5 is transferred to the air-flow drying unit 20, which is essentially formed by a drying cylinder 18, two hoods 28 and a dryer 27.
• the fibrous web 5 is guided in an analogous manner to the air flow drying device 19 through the air flow drying device 20, with the difference that now the fibrous web 5 in the air flow drying unit 20 the side of the fibrous web 5 is supplied with air, which has shown in the air flow drying unit 19 to the dryer fabric 25, so it was not flown with air.
• the fibrous web 5 is treated symmetrically.
• the fibrous web 5 in all major sections i. in the Formierpartie 2, the press section 3 and the dryer section 4 are each treated symmetrically, which is a prerequisite for a symmetrical structure of the sheet properties and thus good performance properties such as printability, print quality and dimensional stability.
• the temperature of the air flowing in the fibrous web in the two Beerstromtrockenei units 19 and 20 is 15O 0 C or more, preferably 18O 0 C or more and more preferably 22O 0 C or more.
• the inventive machine 1 for producing a fibrous web is preferably used in processes for producing a fibrous web having a basis weight between 35g / m 2 and 50g / m 2 and a filler content between 10% and 20%, preferably between 15% and 18%, in which the fibrous web is produced at a web speed of 1600 m / min or more, preferably 2200 m / min or more, and more preferably 2400 m / min or more.
• the machine 1 finds use in processes for producing a fibrous web having a basis weight between 50 g / m 2 and 60 g / m 2 and a filler content of between 20% and 40%, preferably between 25% and 40%, at which the fibrous web at a web speed of 1600m / min or more, preferably 2000m / min or more, and more preferably 2200m / min or more.
• the machine according to the invention 1 is used in processes for producing a fibrous web having a basis weight between 60g / m 2 and 120g / m 2 and a filler content of between 15% and 25%, preferably between 18% and 25% in which the fibrous web at a web speed of 1500m / min or more, preferably 1900m / min or more, and more preferably 2100m / min or more.

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Applications Claiming Priority (3)

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• 2005
  • 2005-08-04 JP JP2007526446A patent/JP4906724B2/ja not_active Expired - Fee Related
  • 2005-08-04 US US11/660,574 patent/US7776185B2/en not_active Expired - Fee Related
  • 2005-08-04 EP EP05771987A patent/EP1778914B1/fr not_active Not-in-force
  • 2005-08-04 AT AT05771987T patent/ATE527410T1/de active
  • 2005-08-04 WO PCT/EP2005/053834 patent/WO2006018388A1/fr active Application Filing

Non-Patent Citations (1)

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