US20070284070A1 - Paper Manufacturing Process - Google Patents

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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
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/06—Paper forming aids
  • D21H21/10—Retention agents or drainage improvers
• • 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
  • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
• • 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
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
  • D21H17/24—Polysaccharides
  • D21H17/25—Cellulose
  • D21H17/26—Ethers thereof
• • 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
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
  • D21H17/24—Polysaccharides
  • D21H17/31—Gums
  • D21H17/32—Guar or other polygalactomannan gum
• • 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
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/37—Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates
  • D21H17/375—Poly(meth)acrylamide
• • 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
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/42—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups anionic
  • D21H17/43—Carboxyl groups or derivatives thereof

Definitions

• the present invention relates to a method for manufacturing a web comprising wood-based fibres and man-made fibres.
• man-made fibres i.e. synthetic fibres or regenerated fibres
• wood-based fibres While the wood-based fibres used have an average fibre length of 1.2 mm, the fibre length of man-made fibres used is usually in the order of 5 mm.
• problems are caused by different fibre lengths and also various other fibre properties.
• One problem is the flocculation of the fibres in the headbox, resulting in poor formation of the web. Long fibres adhere to each other, and they also capture short fibres in the fibre bundles of the long fibres.
• the flocculation tendency can be alleviated by reducing the consistency of the pulp, but the production parameters may thus become such that the production is not possible with conventional machinery and/or the machine speeds must be dropped so low that the production is not profitable.
• Attempts have also been made to manufacture multi-layered paper, wherein diluted pulps can be run at a relatively high speed.
• paper qualities of similar types have been shifted to be manufactured by wet web formation with machinery for non-woven fabrics. To sum up, it has been problematic to run webs comprising man-made fibres in paper machines, and attempts have been made to solve this problem for about 30 years.
• the method according to the invention is characterized in that a polymer is added to a fibre suspension comprising wood-based fibres and man-made fibres, to improve the web formation and to slow down the removal of water in the wire section of the paper machine.
• the above-mentioned problems can be reduced or eliminated by using a polymer mixed in the pulp to improve the web formation and to slow down the removal of water in the wire section of the paper machine.
• the web can be manufactured by utilizing a normal paper machine construction, because there is no need to lower the consistency of the pulp, and thus the size of the slice is sufficient for dosing the pulp onto the wire.
• the consistency is about 1% and the normal running speed is 800 m/min.
• the improvement in the web formation is manifested by the smoothness of the web.
• mechanical means can be used to have an effect on the placement of the fibres in the web.
• the mechanical means include, for example, the intrinsic improvement in the web formation during dewatering, due to the nature of the dewatering, because the fibres tend to move to locations with lower flow resistance and shear forces due to the speed difference between the headbox discharge and the wire.
• Other possible improving mechanisms include shearing forces generated by shaking of the wire and/or oscillation of the surface of the pulp layer.
• Further mechanical means include the effect of suction boxes underneath the forming wire, or it is possible to use a roll on the upper surface of the forming wire to prevent the formation of fibre bundles.
• the polymer to be used in the method according to the invention has a high molecular weight and is relatively unbranched.
• the polymer is preferably anionic.
• Suitable polymers to be used include, for example, anionic polyacrylamide, CMC, guargum, or compounds of these.
• An anionic polyacrylamide suitable for the purpose has a molecular weight of at least 10,000,000 g/mol and an electric charge density of about 30%, and it is dosed 0.2 to 2 kg per ton of fibre.
• CMC has a molecular weight of at least 750,000 g/mol, and it is dosed 2 to 8 kg per ton of fibre.
• the dosage of the polymer can be reduced, because the polymer hardly adheres to the fibre and is thus returned to use.
• the pH value, at which the method works, is neutral or alkaline.
• the pH of the fibre suspension is adjusted to at least 6.5, for the polymer to function in the process.
• the polymer does not function at too high a pH value either.
• the polymer is added either into the pulp mixing tank, before the machine screen, or after the machine screen.
• the method according to the invention is used primarily in the manufacture of wallpaper, particularly in connection with so-called paste-the-wall wallpapers (the adhesive agent is applied onto the wall to be papered and the dry wallpaper is placed onto the adhesive).
• the content of man-made fibres with a typical fibre length of 5 mm is often 10 weight-%, but in a wallpaper made by the method according to the invention, the content may be 15 to 50 weight-%.
• the man-made fibre to be used is polyester, because it has a density suitable for manufacturing with pulp fibres.
• the method is cost-efficient, as the paper can be made according to the conventional paper machine concept.
• the method according to the invention can be applied in products which are presently made by the wet web formation technique, such as filter papers, dust bags for vacuum cleaners, wet-strength towels, bed sheets and linen papers.
• FIG. 1 illustrates the formation (Ambertec formation) as a function of the consistency in the headbox.
• the dosage of anionic polyacrylamide was 1 to 2 kg per ton of fibre.
• the dosage of CMC was 5 to 10 kg per ton of fibre.
• the pH of the fibre suspension in connection with acrylamide was from 7 to 8.
• the pH of the fibre suspension in connection with CMC was from 7 to 8.

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• Paper (AREA)
• Dry Formation Of Fiberboard And The Like (AREA)

Abstract

Description

Claims (6)

Applications Claiming Priority (3)

Publications (1)

Family

ID=32104260

Family Applications (1)

Country Status (7)

Families Citing this family (1)

Citations (17)

Family Cites Families (1)

• 2004
  • 2004-04-14 FI FI20045132A patent/FI20045132A/en unknown
• 2005
  • 2005-04-14 US US11/578,584 patent/US20070284070A1/en not_active Abandoned
  • 2005-04-14 WO PCT/FI2005/050118 patent/WO2005100689A1/en active Application Filing
  • 2005-04-14 EP EP05736333A patent/EP1735497A1/en not_active Withdrawn
  • 2005-04-14 CA CA002561033A patent/CA2561033A1/en not_active Abandoned
  • 2005-04-14 CN CNA200580011274XA patent/CN1942630A/en active Pending
  • 2005-04-14 JP JP2007507808A patent/JP2007532792A/en active Pending

Patent Citations (17)

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