CA1295441C - Process for the production of pulped cellulose material, in particular wood fibers, for the production of fiberboard and products produced - Google Patents

Process for the production of pulped cellulose material, in particular wood fibers, for the production of fiberboard and products produced

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Publication number
CA1295441C
CA1295441C CA000574708A CA574708A CA1295441C CA 1295441 C CA1295441 C CA 1295441C CA 000574708 A CA000574708 A CA 000574708A CA 574708 A CA574708 A CA 574708A CA 1295441 C CA1295441 C CA 1295441C
Authority
CA
Canada
Prior art keywords
wood
steam
wood fibers
resin
process according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA000574708A
Other languages
French (fr)
Inventor
Henricus J. Lanters
Jacobus J.M. Bremmers
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hoechst AG
Original Assignee
Hoechst AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=6334325&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=CA1295441(C) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Hoechst AG filed Critical Hoechst AG
Application granted granted Critical
Publication of CA1295441C publication Critical patent/CA1295441C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N1/00Pretreatment of moulding material
    • B27N1/02Mixing the material with binding agent
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N1/00Pretreatment of moulding material

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Dry Formation Of Fiberboard And The Like (AREA)
  • Paper (AREA)
  • Absorbent Articles And Supports Therefor (AREA)
  • Prostheses (AREA)
  • Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
  • Removal Of Floating Material (AREA)
  • Photoreceptors In Electrophotography (AREA)

Abstract

Abstract of the Disclosure A process is provided for the production of pulped cellulose material, preferably wood fibers, in particular up to a fiber length of 20 mm, with a high proportion of thermocurable resin, the process being suitable, in particular, for the production of fiber-containing moldings. In this process, the thermocurable resin, in aqueous, preferably alkaline solution, is added to a mixture of fiber particles and steam, and the steam is removed from the resin-coated fiber particles in a drier. The steam is removed from the mixture of steam and fiber particles after addition of the resin, and the fiber particles are subsequently dried in a drying stage to a moisture content of less than 12% by weight, in particular 3 to 10% by weight.

Description

1295~ ~1 PROCESS FOR THE PRODUCTION OF PULPED CELLULOSE
NATERIAL, IN PARTICULAR WOOD FIBERS, FOR THE
PRODUCTION OF FIBERBOARD AND PRODUCTS PRODUCED

Background of the Invention The present invention relates to a process for the production of pulped cellulose material, in particular wood fibers, up to a fiber length of 20 mm, with a high proportion of thermocurable resin.
The coated wood fibers are suitable for the production of decorative moldings, where they are initially shaped to form a fiber mat and then compressed at high temperature.
The process according to the present invention proceeds from known processes in which wood chippings are initially softened using steam and subsequently comminuted, for example, between two grinding disks,to for~ wood fibers having a length of up to 20 mm. An aqueous alkaline solution of a thermocurable resin is then applied to the moist wood fibers, and the coated ~ 20 wood fib-rs are dried, for example, using hot air, to : , 12954~1 a residual moisture content of less than 15% by weight (see European patent application No. 00 81 147). When carrying out this known process, however, there is the danger of the resin-coated particles sticking to the drying tube wallduring drying and, in an extreme case, blocking the drying tube, which can easily cause autoignition.
It is also known to transport the wood fibers after the pulping station in a steam/air stream, to remove the major part of the steam stream from the wood fibers before applying the resin, to apply the aqueous resin solution to the fiber particles carried by the residual steam stream in a blow plant, and then to dry the coated wood fibers tsee German Offenlegungsschrift No. 3,609,506). Although this process has the advantage that relatively little energy is necessary during drying, due to the previously reduced proportion of steam, there is a danger in this process of the resin solution mixing insufficiently with the wood fibers and of undesired pre-compression occurring, which can cause problems during further processing of the coated wood fibers.
For example, poor mixing of wood fibers with the resin can result in the formation, by drying resin drops, of glue nests in the finished board.
These nests result in undesired reductions in the ; optical and technical quality. These disadvantages of the known process are particularly serious if relatively large amounts of resin, relative to the amount of wood fibers, are to be employed, as is : ; proposed, for example, in European patent application No. 00 81 147. A further disadvantage is that, with the use of large amounts of resin in accordance with .

1;Z954 ~1 the aforesaid patent application, the line labeled 28 in the figure of Offenlegungsschrift No. 3,609,506 would become blocked with resin and fiber particles.

Summary of the Invention It is therefore an object of the present invention to provide a process which ensures uniform mixing of the fiber particles with the resin, even when large amounts of resin are used, relative to the amount of the fiber particles, and which obviates the danger of blockage (and consequent autoignition) of the drying tube by fiber particles adhering to one another.
It is also an object of the present invention to provide a process which entails inexpensive transport of the fiber particles, i.e., the process can be carried out at low equipment cost, and the energy expense is relatively low, only small amounts of steam being necessary in spite of the large amount of added resin. The combination of all these advantages has hitherto not been achieved by any process.
In accomplishing these objects, there has been provided, in accordance with one aspect of the present invention, a process for producing pulped wood fiber material, comprising the steps of (A) treating wood chippings with steam to soften the chippings, (B) thereafter comminuting said chippings to form wood fibers, (C) providing a mixture of said wood fibers with steam and adding to said mixture an aqueous solution containing a thermocurable resin, such that said wood fibers are coated with said ' ... . .

lZ9~4~

resin, and (D) then removing steam from said mixture and drying said wood fibers to a moisture content of less than 12% by weight. In a preferred embodiment, the wood fibers are dried to a moisture content of 3 to 10% by weight.
According to another aspect of the invention, there has been provided a process for producing a board, comprising the hot compressing of cellulose material, such as wood fibers, coated with thermocurable resin as described above.
There has also been provided, in accordance with yet another aspect of the present invention, a decorative board comprising a core layer and a single or double-sided decorative layer, in which board the core layer comprises the fiber particles produced in accordance with the process described above. The board is a sheet-like object whose surface form and surface structure are matched to the purpose of application and which can also, for example, have a curved shape. The board is preferably an object having an essentially planar surface. Its thickness is, in particular, in the range of about 0.5 to 30 mm. Boards of this general type are described, in particular, in European patent application No. 00 81 147. The board according to the present invention expediently has a scratch-proof surface, as described in European patent applications No. 01 66 153 and No. 02 16 269.
Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description ~ and the specific examples, while indicating preferred il~
;, ~ -4-.

i.,, ~. ... ,, ,, ~ , ~25~54~

embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Brief Description of the Drawings The present invention is illustrated in greater detail below by reference to the figure. The figure is a schematic representation of process within the present invention.

Detailed Descri~tion of the Preferred Embodiments Pulped cellulose material is taken to mean, in particular, fibrous wood particles. They are produced from types of wood which allow pulping, for example from softwood, such as spruce or pine, or hardwood, such as chestnut or beech. Furthermore, cellulose fibers and industrial wood, paper and cellulose waste, for example, sawdust or ground pulp, can be used in addition to the wood fibers; waste from wood-processing workshops is also suitable. It is also possible to replace part of the wood fibers, the cellulose fibers or the wood waste, preferably up to 20% by weight, by plastic waste, for example in the form of fibers or granules. The wood is washed in order to remove traces of metal, stones or sand and then comminuted in a mill to form wood chippings.

~29~4`~1 With reference to the figure, wood chippings are fed continuously with approximately an equal amount by weight of water into a vessel 1 and are treated with hot steam in the kettle 2. After a residence time of a few minutes, the softened chippings are transported on to a refiner 3, where they are comminuted between two grinding disks to form wood fibers. The wood fibers are passed on using hot steam in a blow plant 4 into which thermocurable phenol-formaldehyde resin is sprayed in aqueous alkaline solution via the resin injector 5.
In the subsequent part, the blow plant 4 is cooled externally using water (cooling jacket 6). The mixture obtained comprising steam and resin-coated wood fibers then passes into a cyclone separator 7 under atmospheric pressure. Here, the steam is removed and fed back via the line 8 to the chippings vessel 1 in order to heat the wood particles. The resin-coated or impregnated wood fibers are fed, for the remaining drying, through a star feeder 9 into a drying tube 10, which they leave with a residual moisture content of 7% by weight. The wood fibers are transported on by the drier air into a cyclone separator 11 and passed through a star feeder into a shaping station 12, where they are deposited on a belt and pre-compressed to form a fiber mat.
The wood chippings are softened in a digester (steam kettle) using steam under a steam pressure of 1 to 10 bar for a few minutes and subsequently comminuted, for example between two grinding disks in a refiner, to form wood fibers.
The wood fibers digested in this way have a length of 0.3 to ~0 mm, a mean length of 0.5 to 3 mm .

~ i~......

12954 ~1 and a mean diameter of 0.025 to 0.05 mm. The diameter range is between 0.01 and 1 mm, depending on the raw wood used and the pulping conditions. The length and cliameter of the cellulose fibers used are in the same range of dimensions.
The fiber particles emerging from the pulping machine are transported on in the hot steam stream in a blow plant under increased pressure preferably at 2 to 10 bar, in particular 4 to 6 bar, in turbulent flow.
The addition of the thermocurable resin takes place in aqueous solution, preferably an alkaline aqueous solution, which is sprayed into the blow plant. Due to the turbulent flow, caused by appropriately small dimensions of the blow line and a pressure difference applied over the length of the blow line, optimum mixing takes place between the resin and the fiber particles, even in the case of very large amounts of resin, which can amount to 200 20 to 1000 g, in part~cular 300 to 600 g, per 1000 g of dry fibers. The thermocurable resin is preferably a phenol-formaldehyde resin, as is customary in the production of decorative building board (see European patent application No 00 81 147).
It has proven particularly advantageous to cool the blow plant externally in the region downstream of the resin addition, preferably as far as the removal of steam, so that a thin film of condensed water deposits on the inner wall of the blow plant. For this purpose, it is sufficient for the temperature of the blow plant wall to be reduced by a few degrees, and a temperature reduction of 5 to 20C has proven expedient. Adhesion of the resin-. .

1295~ ~1 coated fiber particles to the inner wall of the blow plant is thus effectively prevented.
The mixture of steam and resin-coated fiber particles is transported by the blow plant to a unit where the steam is removed from the resin-coated fiber particles. In this stage the steam is preferably removed completely. After this, the fiber particles still have a w~ter content of 15 to 35% by weight, in particular 18 to 25% by weight. This stage is advantageously carried out in a cyclone separator at atmospheric pressure, in particular without supply of energy, but other equipment with which systems comprising solid particles, such as, for example, dust and gases can be separated from one another is, in principle, also suitable. Such equipment is, for example, an apparatus which operates on the principle of gravity or centrifugal force and/or is constructed from filters or mechanical separators. See "Dust Collector Design"
ln PERRY'S CHEMICAL ENGINEERS' HANDBOOK 20-81 to 20-89 (6th ed. 1985), McGraw-Hill Book Company. For energy-saving reasons, the steam removed is fed back into the process and expediently used for warming and softening the wood chippings still to be pulped. It is also possible to remove excess curable resin together with the steam and re-use it.
In the subsequent drying stage, the final moisture content of less than 12% by weight, in particular 3 to 10~ by weight, is reached. For this purpose, the fiber particles are expediently blown through a drying tube heated with warm air, the particles being finely divided by the air stream.
The warm air preferably has a temperature from 60 to . .. . . .

1295~1 110C. The dried fibers leave the drying stage, for example, via a further cyclone separator or similar equipment and are processed further, in particular for the production of decorative building board, as described, for example, in European patent application No. 00 81 147.
The process of the present invention exhibits a combination of advantages in a surprising manner.
Thus, the presence of steam in the drier is substantially prevented, which means that the energy requirement is relatively low. The danger of fire is also significantly reduced. There is no danger of the function of either the blow plant or the drier being impaired by adhering material. The process does not require great equipment expenditure, and additional units for mixing and/or transporting the fiber particles are not necessary. The fibers obtained after the drying stage are not agglomerated, which means that they can easily be molded into compressible fiber mats.

,, .. ~ ~ ~ . .. ..

Claims (15)

1. A process for producing pulped wood fiber material, comprising the steps of (A) treating wood chippings with steam to soften the chippings, (B) thereafter comminuting said chippings to form wood fibers, (C) providing a mixture of said wood fibers with steam, and adding to said mixture an aqueous solution containing a thermocurable resin, such that said wood fibers are coated with said resin, and (D) then removing steam from said mixture and drying said wood fibers to a moisture content of less than 12% by weight.
2. A process according to claim 1, wherein said wood fibers are dried to a moisture content of 3 to 10% by weight.
3. A process according to claim 1, wherein said wood fibers are dried during step (D) with warm air at a temperature between about 60°C and 110°C.
4. A process according to claim 1, wherein said aqueous solution is an alkaline aqueous solution containing said thermocurable resin.
5. A process according to claim 1, comprising the steps of transporting said wood fibers in a steam stream to a mixing zone, adding said resin to said mixture to coat said fibers, and conveying said mixture through an externally cooled transport line where the steam is removed, and thereafter drying said wood fibers.
6. A process according to claim 5, wherein the steam stream transporting said wood fibers is conveyed under pressure in turbulent flow.
7. A process according to claim 6, wherein said pressure is in the range of 2 to 10 bar.
8. A process according to claim 1, wherein the amount of resin (dry weight) during step (C) is 200 to 1000 g per 1000 g of wood fiber (dry weight).
9. A process according to claim 1, wherein steam removed during step (D) is recirculated and used to soften untreated wood chippings.
10. A process as claimed in claim 1, wherein step (D) comprises drying said wood fibers with dry air and then separating wood fibers from the dry air.
11. A process according to claim 1, comprising comminuting said wood chippings under steam pressure to a maximum fiber length of 20 mm to produce fiber particles, thereafter transporting said fiber particles with steam under pressure to a mixing zone and spraying said aqueous solution into the mixing zone to coat said wood fiber particles with resin.
12. A wood fiber material produced by the process of claim 1.
13. A method of producing a board, comprising the step of hot compressing wood fiber material produced by the process of claim 1.
14. A board produced by the method of claim 13.
15. A decorative board comprising a core layer and at least one decorative surface layer, said core layer being the product of the process of claim 13.
CA000574708A 1987-08-22 1988-08-15 Process for the production of pulped cellulose material, in particular wood fibers, for the production of fiberboard and products produced Expired - Fee Related CA1295441C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEP3728123.2 1987-08-22
DE19873728123 DE3728123A1 (en) 1987-08-22 1987-08-22 METHOD FOR THE PRODUCTION OF FRINGED CELLULOSE MATERIAL, IN PARTICULAR WOOD FIBERS, FOR THE PRODUCTION OF FIBER PANELS

Publications (1)

Publication Number Publication Date
CA1295441C true CA1295441C (en) 1992-02-11

Family

ID=6334325

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000574708A Expired - Fee Related CA1295441C (en) 1987-08-22 1988-08-15 Process for the production of pulped cellulose material, in particular wood fibers, for the production of fiberboard and products produced

Country Status (10)

Country Link
US (1) US4937100A (en)
EP (1) EP0304764B1 (en)
JP (1) JPS6471704A (en)
AT (1) ATE86166T1 (en)
AU (1) AU601868B2 (en)
CA (1) CA1295441C (en)
DE (2) DE3728123A1 (en)
DK (1) DK167428B1 (en)
FI (1) FI883833L (en)
NO (1) NO170465C (en)

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DE3891143T1 (en) * 1987-12-16 1990-09-20 Sunds Defibrator METHOD AND DEVICE FOR PRODUCING FIBER PANELS
US5432000A (en) 1989-03-20 1995-07-11 Weyerhaeuser Company Binder coated discontinuous fibers with adhered particulate materials
US5498478A (en) 1989-03-20 1996-03-12 Weyerhaeuser Company Polyethylene glycol as a binder material for fibers
US5230959A (en) * 1989-03-20 1993-07-27 Weyerhaeuser Company Coated fiber product with adhered super absorbent particles
US5064689A (en) 1989-03-20 1991-11-12 Weyerhaeuser Company Method of treating discontinuous fibers
AU665532B2 (en) * 1991-04-26 1996-01-11 Enviroflex Pty. Ltd. Insulation pellets and a process for producing same
WO1993012282A1 (en) 1991-12-17 1993-06-24 Weyerhaeuser Company Hopper blender system and method for coating fibers
DE19515734A1 (en) * 1995-05-03 1996-11-07 Schenkmann & Piel Verfahrenste Process for the production of wood fibers
DE19746383A1 (en) * 1997-10-21 1999-04-22 Hofa Homann Gmbh & Co Kg Fiber panel, manufacturing plant and process
IE990100A1 (en) 1998-10-30 2000-05-03 Masonite Corp Method of making molded Composite articles
DE10037983B4 (en) * 2000-08-03 2006-04-13 Stefan Zikeli Polymer composition and molded articles containing it containing alkaloid
US7410687B2 (en) * 2004-06-08 2008-08-12 Trex Co Inc Variegated composites and related methods of manufacture
DE102004062649C5 (en) 2004-12-21 2013-06-06 Kronotec Ag Process for the production of a wood fiber insulation board or mats and wood fiber insulation boards or mats produced by this process
WO2006092603A1 (en) * 2005-03-02 2006-09-08 University Of Wales, Bangor Treatment of long fibres in a high pressure gas stream
DE102008026677B3 (en) * 2008-06-04 2009-10-22 Kronotec Ag Drying lignocellulose fibers, for fiberboard production, has a separator to detach fibers from a steam flow for drying with recovered steam for heating the wood chip start material
DE102008056650A1 (en) * 2008-11-10 2010-05-12 Martin Dreisman Composition and method of making a wood or fiberboard
AT509429B1 (en) * 2010-01-20 2016-09-15 Erema METHOD FOR PRODUCING A POLYMERIC MATERIAL FILLED WITH LONGER FIBERS
IT1399772B1 (en) 2010-04-30 2013-05-03 Imal Srl APPARATUS FOR THE INJECTION OF CHEMICAL COMPONENTS IN A FLOW OF NON-INCORRENT WOODEN MATERIAL
US9061437B2 (en) * 2010-10-01 2015-06-23 Kronoplus Technical Ag Method and apparatus for gluing wood particles
WO2013178287A1 (en) * 2012-06-01 2013-12-05 Dieffenbacher Gmbh Maschinen Und- Anlagenbau Bend for introducing a steam-and-fibers stream into a dryer or a pulp chest of a fibers-processing plant, blow line with a bend, and fibers-processing plant with a blow line
AT514329B1 (en) * 2013-08-01 2014-12-15 Andritz Ag Maschf Plant and method for processing fibrous materials
AT514330B1 (en) * 2013-08-01 2014-12-15 Andritz Ag Maschf Plant and method for processing fibrous materials

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2817617A (en) * 1953-03-19 1957-12-24 Hugh R Rogers Process of manufacturing board-like articles
DE3147989A1 (en) 1981-12-04 1983-06-16 Hoechst Ag, 6230 Frankfurt DECORATIVE, IN PARTICULAR PLATE-SHAPED MOLDED PART, METHOD FOR THE PRODUCTION THEREOF AND THE USE THEREOF
DE3418282A1 (en) * 1984-05-17 1985-11-21 Hoechst Ag, 6230 Frankfurt DECORATIVE PLATE WITH IMPROVED SURFACE PROPERTIES
DE3609506A1 (en) * 1985-03-25 1986-10-30 Koppers Co., Inc., Pittsburgh, Pa. Process for producing a composition from cellulose particles and resin for the production of fibre boards
DE3533737A1 (en) * 1985-09-21 1987-03-26 Hoechst Ag DECORATIVE PLATE WITH IMPROVED SURFACE PROPERTIES

Also Published As

Publication number Publication date
FI883833A7 (en) 1989-02-23
NO170465B (en) 1992-07-13
EP0304764B1 (en) 1993-03-03
DE3728123A1 (en) 1989-03-02
FI883833L (en) 1989-02-23
DK465988A (en) 1989-02-23
ATE86166T1 (en) 1993-03-15
EP0304764A2 (en) 1989-03-01
NO883735D0 (en) 1988-08-19
US4937100A (en) 1990-06-26
AU601868B2 (en) 1990-09-20
NO883735L (en) 1989-02-23
NO170465C (en) 1992-10-21
DK465988D0 (en) 1988-08-19
FI883833A0 (en) 1988-08-18
DK167428B1 (en) 1993-11-01
EP0304764A3 (en) 1989-11-29
JPS6471704A (en) 1989-03-16
AU2107488A (en) 1989-02-23
DE3878785D1 (en) 1993-04-08

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