Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
• • 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
  • D21H17/28—Starch
• • 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
• • 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
  • D21H21/50—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 characterised by form
• • 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
  • D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
  • D21H11/16—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only modified by a particular after-treatment
  • D21H11/18—Highly hydrated, swollen or fibrillatable fibres
• • 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
  • D21H21/14—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 characterised by function or properties in or on the paper
  • D21H21/18—Reinforcing agents
• • 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
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
  • D21H27/30—Multi-ply

Definitions

• the present invention relates to a process for production of a paper or paperboard product comprising a furnish which comprises starch and microfibrillated cellulose.
• fillers also improve the opacity and printability properties of the product.
• large amount of fillers in the product decreases the strength.
• there is a desire to produce a strong but yet low density product When increasing the strength of a paperboard the density normally increases. There is thus a balance between the desired strength and the density of the paperboard product.
• the predominant treatment for improving paper or paperboard strength has so far been to add a strength agent, preferably cationic starch, to the furnish prior to the sheet forming operation.
• a strength agent preferably cationic starch
• Cationic starch molecules added to the furnish can adhere to the naturally anionic pulp fibers by electrostatic attraction and thus be retained in the wet fiber mat and remain in the final paper or paperboard.
• cationic starch molecules tend to saturate the anionic charge on the cellulose fibers, thus setting a limit to the amount of cationic starch which can be added to the slurry. If an excess of cationic starch is added, only a portion of the starch added will be retained in the sheet, and the rest will circulate in the paper or board machine white water system.
• a second problem is that fibers which are made cationic by excessive cationic starch addition will not be able to adsorb other cationic additives which are commonly added to the pulp slurry, such as sizing agents and retention aids.
• high amounts of starch often cause problems with runnability, microbiology and foaming during the production process.
• the present invention relates to a process for producing a paper or paperboard product which process comprises the steps of; providing a furnish comprising fibers, adding starch to the furnish, adding microfibrillated cellulose to the furnish and conducting the furnish to a wire in order to form a web, wherein the starch and microfibrillated cellulose is added separately to the furnish.
• a product comprising both starch and microfibrillated cellulose (MFC) increases the strength of the product since the amount of starch can be increased without increasing the density of the paper or paperboard product.
• the furnish comprises 2-15% by weight of starch and 1-15% by weight of microfibrillated cellulose.
• the amount of starch is preferred.
• the web being formed by said furnish comprising starch and
• microfibrillated cellulose preferably forms a layer of the paper or paperboard product.
• the paper or paperboard product is preferably a multilayer product which comprises at least two layers. It may be preferred that the product comprises at least three layers and that the layer located in the middle of the product comprises furnish comprising starch and microfibrillated cellulose, i.e. the web being formed by the furnish that comprises starch and MFC, forms a middle layer of the paper or paperboard.
• the invention relates to a process for production of a paper or paperboard product comprising a furnish which comprises starch and microfibrillated cellulose.
• the furnish comprises starch in an amount of 2-15% by weight, preferably between 3-5% by weight. Consequently, the product thus comprises starch of an amount of 2-15% by weight, preferably between 3-5% by weight.
• the furnish preferably comprises cellulosic fibers.
• the cellulosic fibers may be hardwood and/or softwood fibers.
• the cellulosic fibers may be mechanically, chemimechanically and/or chemically treated.
• the fibers may also be bleached or unbleached.
• the weight of the product will be decreased which will reduce costs during transportation and handling.
• Microfibrillated cellulose (also known as nanocellulose) is a material made from wood cellulose fibers, where the individual microfibrils have been partly or totally detached from each other. MFC is normally very thin ( ⁇ 20 nm) and the length is often between 100 nm to 10 pm. However, the microfibrils may also be longer, for example between 10-100 pm but lengths up to 200pm can also be used. Fibers that has been fibrillated and which have microfibrille on the surface and microfibrils that are separated and located in a water phase of a slurry are included in the definition MFC.
• MFC can be produced in a number of different ways. It is possible to mechanically treat cellulosic fibers so that microfibrils are formed. The production of nanocellulose or microfibrillated cellulose with bacteria is another option. It is also possible to produce microfibrils from cellulose by the aid of different chemicals and/or enzymes which will break or dissolve the fibers.
• MFC One example of production of MFC is shown in WO2007091942 which describes production of MFC by the aid of refining in combination with addition of an enzyme.
• microfibrillated cellulose before addition to the furnish. In this way it is possible to change its interaction and affinity to other substances. For example, by introducing more anionic charges to MFC the stability of the fibril and fibril aggregates of the MFC are increased. How the modification of the microfibrillated fibers is done depends, for example on the other components present in the furnish.
• the furnish comprises 2-15% by weight of starch, preferably between 3-5% by weight, and it is preferred that the furnish further comprises MFC in an amount of 1 -15% by weight.
• the chosen amount of starch respectively MFC added to the furnish depends on the final product produced and the desired properties of the product. Higher amounts of starch will increase the strength of the product.
• the paper or paperboard product is preferably a multilayer product comprising at least two layers. It may be preferred that the product comprises at least three layers and that the layer located in the middle of the product comprises furnish comprising starch and microfibrillated cellulose. However, it is also possible that at least one outer layer of the product or even all layers of the product comprises furnish comprising starch and MFC. For some products it might be advantageous that at least one of the outer layers comprises furnish comprising starch and MFC. In this way it is possible to increase the strength and/or the bulk of this layer. Consequently, depending on the end use of the product, it is decided which and how many of the layers that will comprise furnish comprising starch and MFC.
• the entire furnish in a layer of the paper or paperboard product comprises starch and MFC, but it is preferred that the starch and MFC is added to the majority of the furnish of the layer.
• the layer may also comprise other components, such as broke pulp which does not comprise starch and MFC.
• the furnish may also contain various amounts of fillers to increase for example runnability and cost-efficiency of the process and the produced substrate.
• Other commonly used additives used in the production of paper or paperboard can also be added.
• the paperboard product is preferably a high quality paperboard product, such a liquid packaging board, graphical board or food service board.
• the paper product is preferably a high quality paper, such as copy paper of grades A or B, graphical papers, LWC, SC or news paper for high speed printing machines.
• the process for producing a paper or paperboard product which process comprises the steps of providing a furnish comprising fibers, adding starch to the furnish, adding microfibrillated cellulose to the furnish and conducting the furnish to a wire in order to form a web.
• the addition of starch and MFC is preferably done in the machine chest or before the fan pump. It may also be possible to do the addition to the circulation water which later on is added to the furnish.
• starch and MFC all practical points of addition for the starch and MFC can be used as long as there is enough time and mixing of the starch and MFC with the furnish before it is conducted to the wire.
• the starch and MFC is added separately. It is preferred to first add starch followed by addition of MFC. It could be possible to mix the starch and MFC before addition to the furnish, however the result is then not as good as when starch and MFC is added separately. It is then possible to mix starch and MFC before addition to the furnish by cooking them, preferably by the use of a jet-cooker. It has been shown that by cooking the mixture of starch and MFC, the MFC shows less tendency to flocculate. Furthermore, by altering the charge and charge density of e.g.
• starch different degrees of flocculation can be obtained and it would thus be possible to neutralize the charge of MFC. This might affect dewatering and retention of the fibers and eventual fillers in the product. It may also be possible to add a layer of starch on the MFC and then add this mixture to the furnish, i.e. a multilayering effect can be created.
• BCTMP Bleached chemothermomechanical pulp
• Microfibrillated cellulose was prepared by refining bleached hardwood sulphite pulp of 4% consistency with edge load of 2 Ws/m to 28 SR. The pulp were thereafter enzymatically treated with Endoglucanase (Novozym 476) with the activity of 0,85 ECU/g. The enzymes were dosed to the pulp and which thereafter was treated at 50°C for 2 hours, at pH 7. After the enzymatic treatment, the pulp was washed and enzymes were
• Starch used was cationized starch, Raisamyl 70021 , Ciba (now BASF).
• C-PAM used was Percol 292 NS, Ciba (now BASF).
• BMA used was Eka NP495, Eka Chemicals.
• Example 1 BMA used was Eka NP495, Eka Chemicals.
• the dried BCTMP were soaked in water over night and then dispersed in hot water.
• the BCTMP suspension was thereafter diluted to a
• the produced MFC was also diluted to a concentration of 0.3% and dispersed using a kitchen mixer.
• a formette sheet former was used to prepare the sheets for testing.
• the sheets were prepared according to the following procedure; Pulp suspension measured to produce a 150gsm sheet was added to the stock tank. During agitation, starch if used, and MFC if used, was added. After 30 seconds, 500g/t C-PAM was added and after another 30 seconds was 300g/t BMA added to the stock and the sheet forming was thereafter started. The formed sheet was wet pressed and dried while the shrinkage was constrained. The dried sheet was tested for structural density according to SCAN P 88:01 , z-strength according to SCAN P 80:88 and tensile strength index according to ISO 1924-3.
• the MFC and cationic starch were well mixed before addition to the stock.
• cationic starch was first added and well mixed with the stock for 5 minutes followed by addition of MFC.
• MFC in an amount of 25 kg/t and cationic starch in an amount of 20 kg/t were added in both samples, both the pre-mixed and the separately added.
• a formette sheet former was used in the same manner as described in Example 1 .

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Nanotechnology (AREA)
• Physics & Mathematics (AREA)
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• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Materials Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
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Citations (5)

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• 2009
  • 2009-12-03 SE SE0950930A patent/SE535014C2/sv not_active IP Right Cessation
• 2010
  • 2010-11-30 BR BR112012013447A patent/BR112012013447A2/pt not_active Application Discontinuation
  • 2010-11-30 JP JP2012541974A patent/JP2013513037A/ja not_active Abandoned
  • 2010-11-30 US US13/513,410 patent/US20120241114A1/en not_active Abandoned
  • 2010-11-30 WO PCT/SE2010/051322 patent/WO2011068457A1/en active Application Filing
  • 2010-11-30 RU RU2012127561/05A patent/RU2012127561A/ru not_active Application Discontinuation
  • 2010-11-30 CN CN2010800545291A patent/CN102639788A/zh active Pending
  • 2010-11-30 EP EP20100834832 patent/EP2507432A4/de not_active Withdrawn
  • 2010-11-30 CA CA2782342A patent/CA2782342A1/en not_active Abandoned
  • 2010-11-30 AU AU2010327382A patent/AU2010327382A1/en not_active Abandoned
  • 2010-11-30 NZ NZ600151A patent/NZ600151A/xx not_active IP Right Cessation
• 2012
  • 2012-05-22 ZA ZA2012/03737A patent/ZA201203737B/en unknown
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