Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
  • D21B1/00—Fibrous raw materials or their mechanical treatment
  • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
  • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
  • D21B1/30—Defibrating by other means
  • D21B1/32—Defibrating by other means of waste paper
  • D21B1/322—Defibrating by other means of waste paper coated with synthetic materials
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21J—FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE
  • D21J1/00—Fibreboard
  • D21J1/16—Special fibreboard
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/64—Paper recycling

Definitions

• This invention relates to a method for manufacturing fiber boards, comprising the steps of desintegrating a fiber raw mate ⁇ rial while exposing individual fibers out of the same, diluting the fibers in water while forming a beating material which is distributed on an endless wire and dewatered in order to form a substantially uniformly thick fiber web in which the fibers are held together at least provisionally in a comparatively fluffy network, dividing said fiber web into sequential individual sheets intended for forming boards, and transferring said fiber sheets to a drying station in which they are subjected to a heat treatment in order to evaporate further water and provide an in- timate binding of the fibers in said network so as to get the sheet to form a board having a stiff nature.
• wood is used as the raw material source; usually in the form of chips or shavings which is delivered as surplus materials or by-products from saw mills after gaining sawn elements out of round timber.
• This chip or- shaving material is treated in the board factory by pre-conditioning with hot-water, steaming (e.g. at 120°C) and possibly a chemical impregnation treatment. Thereafter, the material is passed through a defibrator having a grinding sta ⁇ tion resulting in the individual fibers of the softened chip or shaving bodies being exposed. These exposed fibers are diluted in water while forming a beating material, which is then treated in the manner generally described above.
• the boards are produced in two different de ⁇ signs, namely on one hand a porous variant, and on the other hand a hard or semi-hard variant.
• porous boards are produ ⁇ ced
• the fiber sheets obtained from the wire of the take-up machine are dried in a pressure-free or relaxed condition in a relatively short period of time (1-2 hours) and under temperatu ⁇ res in the range of 170-180°C.
• the fiber sheets are additionally subjected to a treatment in a high pressure press, preferably a multiple ope ⁇ ning press.
• the sheets are pressed between plates provided with pressing wires under a pressure in the order of 35-40 kg/cm 2 at the same time as they are subjected to a tempe- rature of, for example 200°C. Thereafter the sheets are heat- hardened at temperatures within the range of 160-215°C for a time of, for example 5 to 7 hours, so that a compact, strong and water-resistant board is achieved, the thickness of which (most commonly 2-9 mm) is normally quite thin compared to the thick- ness of the porous boards (most commonly 9-25 mm) .
• the natural content of lignin and resin products of the wooden material which is exposed during defibration of the chips or shavings is used as the sole binding agent between the fibers of the board.
• the present invention is based on the surprising realiza ⁇ tion that not only is it possible, but that it is extra-ordina- rily advantageous to use, as a fiber raw material, packaging capsules made from thermoplastic-coated paperboard instead of, or as a complement to, the conventional wood raw material in the form of chips or shavings.
• Thermoplastic-coated paper board is mainly produced from one or several layers of a fiber pulp. At least one of these layers of fiber pulp is made from a semi-che- mical pulp and at least one of the surface layers of the finished paper board is coated with a thermoplastic in the form of polyethylene. The thermoplastic coating gives the paper board a good resistance against fluids.
• Polyethylene-coated paper board may therefore advantageously be utilized in packaging cap- sules for retaining fluids such as drinks, e.g. milk, juice, fruit-syrups, etc.
• fluids such as drinks, e.g. milk, juice, fruit-syrups, etc.
• the interior surface of the paper board included in such capsules is provided with an interior coating in the form of an aluminium foil (usually present in connection with capsules for retaining juice) .
• Such capsules which are distributed daily in extremely large quantities in today's so ⁇ ciety, have previously been regarded chiefly as an environmental problem rather than as a resource of raw material.
• a common way of making the material included in paper board capsules useful has previously been to simply burn the capsules so as to profit on the energy content of the material.
• the fibers of the paper board cannot be used as recovery fibers for the production of paper unless the same are first carefully separa ⁇ ted from the plastic and metal foil materials. This separation calls for a rather complicated cleaning process which is diffi ⁇ cult to control and very expensive to carry out. Consequently for economical reasons, recovery of paper board fibers for the purpose of paper production is impossible in practice.
• a content of approxi ⁇ mately 15 % of polyethylene plastic in conventional recovery pa ⁇ per board capsules forms a quantity of binding agent which, when properly used, gives a stronger binding or so called cross-lin ⁇ king of the fiber structure than lignin.
• the polyethylene plastic included in the recovery paper board capsu ⁇ les should not be regarded as a source giving rise to difficul ⁇ ties, but rather as a truly advantageous resource which gives the finished boards properties which at least in certain respects, namely in respect of modulus of elasticity, hydrophobi and liquid resistance, are improved in comparison with corres ⁇ ponding properties of conventional wooden fiber boards. It has been shown that any aluminium foil accompanying the capsules can be automatically desintegrated in connection with the paper board defibration, and may accompany the fibers in the beating material as well as in the sheets without giving rise to nega ⁇ tive consequences.
• Fig 1 is a digrammatic, extremely simplified perspective view illustrating a board manufacturing plant of type conven ⁇ tionally used for the production of wooden fiber boards,
• Fig 2 is an enlarged perspective view of a desintegrator inclu ⁇ ded in the plant according to Fig 1, and
• Fig 3 is a schematic illustratation of a station included in the plant for treatment of incoming raw material in the form of recovery paper board capsules.
• reference numeral 1 generally designates a desin ⁇ tegrator or desintegrator station in which fibrous raw material is taken from a supply 2 via a conveyor 3, e.g. of the type including one or more feed screws.
• Reference numeral 4 generally designates a take-up machine which in a conventional manner includes an endless wire 5, at least one beating or stock regu ⁇ lating box 6 and one or more presses 7 as well as a cutting de ⁇ vice 8.
• the cutting device 8 cuts a fiber web fed forwardly on the wire into individual sheets. Behind the cutting device 8 is a roller table 9. Downstreams of said cutting device is a mul ⁇ tiple opening press 10, which also serves as a drying station.
• each incoming fiber sheet may, depending on requirements, on one hand be pressed with the desired pressure, and on the other hand be subjected to the heat treatment at the desired temperature.
• the treated fiber boards to be hardened are transferred by a car ⁇ riage 11 to a hardening chamber 12.
• the hardening chamber 17 is followed by a moistening or conditioning chamber 13 and by an unloading station 14.
• FIG. 2 illustrates the design of the desintegrator station 1 in an enlarged scale.
• a hopper 15 in which fiber raw material can be received from the conveyor 3.
• a screw feeder 16 connected to the bottom outlet of the hopper 15, feeds the raw material to a column-shaped preheater 17.
• a pipe ⁇ line 18 is connected to the preheater 17 for the supply of steam.
• an agitator 19 At the bottom of the preheater is an agitator 19. Fiber raw material fed into the preheater is wetted and subjected to heat treatment by way of the steam supplied through the pipeline 18, whereby the raw material is softened in order to initiate defibration.
• the raw material is further con ⁇ veyed by a second screw feeder 20 to a defibrator generally de- signated by reference numeral 21.
• a beater or grinder is inclu ⁇ ded in the defibrator 21.
• the raw material is sub ⁇ stantially completely defibrated or desintegrated while forming a pulp of mainly individual fibers.
• From the defibrator 21 the fiber pulp is forwarded through a third screw feeder 22 in which a steam separator is included. Finally the pulp is fed through an outlet 23 which in turn is connected to a stock chest 24 (see Figure 1) .
• Water may be added to the pulp through a water supply pipe 25, in order to dilute the fiber pulp in the water while providing a beating material having a suitable dryness (e.g. within the range of 0,5-2,0, preferably about 1 %) .
• the plant illustrated in Fig 1 and 2 as above described is the same in all essential elements as previously known plants designed to make possible the usual production of fiber boards from wooden raw material, preferably in the form of chips and/or shavings.
• such used and recovered packaging capsules which were initially made from plastic-coated paper board, particularly such paper board which has been coated with polyethylene or other similar thermoplas ⁇ tic, are used instead of the wooden raw material or as a comple ⁇ ment thereto.
• the capsules have to be coarsely decomposed and washed in a first step.
• Figure 3 illustrates how a decomposer device 26 (schematically shown) for the coarse decomposition is included in a station upstream of the receiving hopper 15 of desintegra ⁇ tor 1 together with a washing device or tank 27 and suitably also a pressing machine 28 by means of which decomposed and washed paper board pieces can be pelletized or shaped and comp ⁇ ressed into pellet or briquette like bodies which can be trans ⁇ ported through the screw feeder to the desintegrator 1 easier than differently shaped paper board pieces.
• a strainer 29 arranged to dewater the washed paper board pieces.
• the capsules 31 may constitute "source-sorted" (sorted at the source) , milk, juice or fruit drink packages of the type distributed in great quanti ⁇ ties through everyday commerce, and which, after consumption of the contents, are thrown by the consumer.
• source-sorted sorted at the source
• milk, juice or fruit drink packages of the type distributed in great quanti ⁇ ties through everyday commerce, and which, after consumption of the contents, are thrown by the consumer.
• packages which are interiorly coated with a metal foil, usually an aluminium foil may be included.
• the decomposer device 26 may be any known or arbitrary de- vice, e.g. a screw desintegrator, which is suitable to effecti ⁇ vely tear or destroy great quantities of paper board.
• Washing device 27 preferably operates with water as a washing agent. Chemical cleaning agents may be added to the wash water in order to achieve an optimum cleaning effect . It is important that the washing device 27 be located downstream of the decomposer 26 in order to make possible a washing of the decomposed, relatively small paper board pieces which have their outer surface as well as their inner surface exposed to the washing liquid.
• the paper board material will automati ⁇ cally be dewatered when the same is agglomerated and compressed in the pressing machine 28, whereby said material will be given the desired dryness when it reaches the preheater 17 of desin- tegrator 1.
• a cleaning basin 33 is also included in the station shown in Figure 3. From the cleaning basin 33 the wash water can be returned to the washing tank 27 via a recirculation piping sys ⁇ tem 34. From the supply 35 of pellets fed out from the pressing machine 28 the material can be forwarded to the desintegrator station 1 by the conveyor 3 shown in Figure 1.
• recovery paper board capsules as a fiber raw material according to the invention can be realized in a number of alternative ways.
• said material can be used as the single fiber raw material in each individual board.
• the quantities of paper board recovery fibers in the finished board are within the range of 80-100 %.
• the proper production of fiber boards from paper board recovery fibers as the single or partial fiber raw material is carried out substantially in the same manner as in the conventional pro ⁇ duction by means of fibers from wooden raw material.
• the fiber mass is fed from desintegrator 1, in the form of a beating material, out on the wire 5 of the take-up machine.
• the fiber mass is dewatered to form a substantially evenly thick, conti ⁇ nuous fiber web in which the fibers are held together at least provisionally in a comparatively fluffy network.
• the fiber web is divided, by the cutting device 8, in sequential individual sheets which are transferred to the drying station 10.
• the individual sheets are subjected to a heat treatment and also may be subjected to pressing in order to eva- porate further water and provide an intimate binding of the fibers in the network to make the individual sheet forming a board of a stiff nature.
• a treatment in hardening chamber 12 and moistening chamber 13 takes place.
• a heating of the fibers to at least 150°C occurs, whereby the thermoplastic deposited on the fibers is melted.
• the melted plastics flows out and forms diminutive points of connection between individual fibers in the network while securing an extremely strong cross-linking.
• thermoplas- tic is included in the starting material in such great quanti ⁇ ties, such as about 15 %, a very large number of bindings will be created, whereby not only is strong cross-linking achieved, but also a far-reaching hydrophobation of the finished board is achieved, i.e. the board will have very good resistance to water.
• another advantage of the large con ⁇ tent of thermoplastic in the fiber raw material is as follows . The plastic will be softened already in connection with the treatment in station 1, whereby the plastic tends to bind to the lumen of the fiber such fibrils which would otherwise during the subsequent dewatering on wire 5 render the penetration of the water through the fiber web more difficult.
• thermoplastic due to the relatively great quantity of thermoplastic, a beating material is obtained which can easily be dewatered on the wire.
• Tests performed have shown that a semi-chemical pulp in a pure condi- tion (i.e. without thermoplastic) gives a dewatering degree of about 40° chopperriegler, while a corresponding pulp having about 15 % thermoplastic included in the mixture will give a dewate ⁇ ring degree in the order of 10° chopperriegler.
• the advantages of the invention are obvious. Recovery paper board capsules for various forms of drinks are present in large quantities and may after sorting at the source be collec ⁇ ted at a low cost for the board manufacturer.
• this material is not only possible to use this material as a fiber raw material, but there are technical advantages sin the form of an improved dewatering degree, increased modulus of elasticity in the finished board as well as improved water resistance and increa ⁇ sed strength in comparison with corresponding boards made from wooden raw material only. Moreover, the invention makes it pos ⁇ sible for the packaging manufacturer to fulfill existing requi ⁇ rements on re-utilization of the packaging material in a simple and economically effective manner.

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Mechanical Engineering (AREA)
• Dry Formation Of Fiberboard And The Like (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20391621

Family Applications (1)

Country Status (5)

Cited By (2)

Family Cites Families (1)

• 1993
  • 1993-11-03 SE SE9303619A patent/SE9303619L/sv unknown
• 1994
  • 1994-10-19 GB GB9608836A patent/GB2298435B/en not_active Expired - Fee Related
  • 1994-10-19 WO PCT/SE1994/000983 patent/WO1995012711A1/en active Application Filing
  • 1994-10-19 AU AU10367/95A patent/AU1036795A/en not_active Abandoned
  • 1994-10-19 DE DE19944498494 patent/DE4498494T1/de not_active Withdrawn

Non-Patent Citations (3)

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