EP0050164A1 - Verfahren zum Herstellen von Bauteilen aus zusammengesetztem Holzmaterial - Google Patents

Verfahren zum Herstellen von Bauteilen aus zusammengesetztem Holzmaterial Download PDF

Info

Publication number
EP0050164A1
EP0050164A1 EP80106370A EP80106370A EP0050164A1 EP 0050164 A1 EP0050164 A1 EP 0050164A1 EP 80106370 A EP80106370 A EP 80106370A EP 80106370 A EP80106370 A EP 80106370A EP 0050164 A1 EP0050164 A1 EP 0050164A1
Authority
EP
European Patent Office
Prior art keywords
structural member
wood flakes
flakes
longitudinal axis
wood
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.)
Granted
Application number
EP80106370A
Other languages
English (en)
French (fr)
Other versions
EP0050164B1 (de
Inventor
Anders E. Lund
Gordon P. Krueger
Darrell D. Nicholas
Roy D. Adams
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.)
Michigan Technological University
University of Michigan Ann Arbor
Original Assignee
Michigan Technological University
University of Michigan Ann Arbor
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
Application filed by Michigan Technological University, University of Michigan Ann Arbor filed Critical Michigan Technological University
Priority to DE8080106370T priority Critical patent/DE3071187D1/de
Priority to EP80106370A priority patent/EP0050164B1/de
Publication of EP0050164A1 publication Critical patent/EP0050164A1/de
Application granted granted Critical
Publication of EP0050164B1 publication Critical patent/EP0050164B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00—Structural elongated elements designed for load-supporting
    • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/12—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members
    • E04C3/14—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members with substantially solid, i.e. unapertured, web
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27N—MANUFACTURE 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
    • B27N5/00—Manufacture of non-flat articles
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
    • E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
    • E04C2/10—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products
    • E04C2/16—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products of fibres, chips, vegetable stems, or the like
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00—Structural elongated elements designed for load-supporting
    • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/28—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of materials not covered by groups E04C3/04 - E04C3/20

Definitions

  • This invention relates to structural members made from a composite wood material comprised of wood flakes bonded together with a binder.
  • the wood particles are deposited so they are either randomly oriented relative to each other or oriented to cross each other.
  • structural members of 1-inch thickness or more produced by such processes generally have strength properties, particularly bending strength along the longitudinal axis, which are inferior to solid wood.
  • a structural member made from a composite wood material containing a binder characterised in that the wood material comprises elongate wood flakes bonded together with said binder, said wood flakes having a grain direction extending generally parallel to the longitudinal axis thereof and at least a majority being oriented such that the longitudinal axis of the flakes is generally parallel to the longitudinal axis of said structural member.
  • the present invention provides a method for making a structural member of a composite wood material which comprises admixing wood flakes with a binder, forming a mat of said mixture and applying pressure to said mat to bond the flakes together, characterised by the preliminary steps of providing elongated wood flakes having a grain direction extending generally parallel to the longitudinal axis thereof and, after admixture with said binder, forming a layered mat of the resulting mixture with at least a majority of the wood flakes oriented such that the longitudinal axis thereof is generally parallel to the axis of the structural member to be formed from the mat.
  • wood flakes having an average length of about 0.5 inch to about 3.5 inches, an average length to average width ratio of about 4:1 to about 10:1 and an average thickness of about 0.01 to about 0.05 inch are used.
  • a suitable binder such as a resinous particle board binder is admixed with the wood flakes and the resulting mixture or furnish is formed into a loosely felted melt with at least a majority, preferably about 90% or more, of the wood flakes oriented such that their longitudinal axis is generally parallel to the longitudinal axis of the structural member to be formed from the mat.
  • the resultant structural member usually has a density of about 38 to about 50, preferably about 42 to about 45 lbs/ft 3 .
  • the resulting structural member preferably contains about 5 to 12 weight % of the binder and, optionally, additives, such as wax, for waterproofing and preservatives for protection against decay fungi and insects.
  • additives such as wax, for waterproofing and preservatives for protection against decay fungi and insects.
  • Organic polyisocyanates are the preferred binder because of the higher strength properties provided thereby.
  • separate elongated structural components are formed and two or more are joined together in angular relationship with a suitable adhesive to form an elongated structural member having an I-beam, angle bar, channel bar, etc. configuration.
  • Fig. 1 Illustrated in Fig. 1 is an elongated structural member 10 made from a composite wood material in accordance with the invention and having a cross-sectional dimension corresponding to a standard lumber 2 X 4.
  • the structural member 10 is molded or pressed as a solid one-piece unit from a mixture of wood flakes 12 and a suitable [resinous particle] board binder as described in more detail below.
  • the wood flakes 12 illustrated at about 2 times normal size
  • Fig. 1 Illustrated in Fig. 1 is an elongated structural member 10 made from a composite wood material in accordance with the invention and having a cross-sectional dimension corresponding to a standard lumber 2 X 4.
  • the structural member 10 is molded or pressed as a solid one-piece unit from a mixture of wood flakes 12 and a suitable [resinous particle] board binder as described in
  • At least a majority of the wood flakes 12 making up the structural member 10 is oriented so that the planes thereof are coextensive or generally parallel to each other and their longitudinal axis 16 is generally parallel to the longitudinal axis 18 of the structural member 10.
  • the grain direction of the thus-oriented wood flakes extends generally parallel to the longitudinal axis 18 of the structural member 10 in a manner similar to a 2 X 4 of natural wood.
  • Figs. 1 and 2 fragmentarily illustrate multi-piece structural members 20 and 40 made from a composite wood material in accordance with the invention.
  • the structural member 20 illustrated in Fig. 2 has an I-beam configuration and includes separate elongate, generally flat, structural components 22, 24 and 26.
  • Each of the structural components 22, 24 and 26 is molded from a mixture of wood flakes 12 and a binder in the same general manner outlined above. That is, at least a majority of the wood flakes 12 making up each of the structural components is oriented so that their planes are coextensive or generally parallel to each other and their longitudinal axis 16 is generally parallel to the longitudinal axis 28, 30 and 32 of the respective structural components 22, 24 and 26.
  • the opposite longitudinal edges 34 and 36 of the intermediate component 24 are bonded to components 22 and 26 by a suitable high strength adhesive 38, such as resorcinol or isocyanate type adhesive or other adhesives suitable for bonding wood products.
  • the structural member 40 illustrated in Fig. 3 has an angle bar configuration and includes separate elongated, generally flat, structural components 42 and 44 which are molded from a wood flakes-binder mixture and bonded together with an adhesive as described above in connection with the I-beam structural member 30.
  • at least a majority of the wood flakes 12 making up the structural components 42 and 44 is oriented so that their planes are coextensive or generally parallel to each other and their longitudinal axis 16 is generally parallel to the longitudinal axis 46 and 48 of the structural components 42 and 44.
  • the process of the invention broadly includes the steps of comminuting small logs, branches or rough pulp wood into flake-like particles, drying the wood flakes to a predetermined moisture content, classifying the dried flakes to a predetermined size, blending predetermined quantities of a suitable binder, and optionally a liquid wax composition, preservatives and other additives with the dried and sized flakes, forming the resultant mixture or furnish into a loosely felted, layered mat (single or multi-layered) and applying sufficient pressure (with or without heat).on the mat to compress it to the desired thickness for the structural member or components therefor and to bond the wood flakes together.
  • Wood flakes used can be prepared from various species of suitable hardwoods and softwoods.
  • suitable woods include aspen, maple, elm, balsam fir, pine, cedar, spruce, locust, beech, birch, Douglas fir and mixtures thereof.
  • Wood exhibits directional strength properties with the strength along the grain being far greater than across the grain.
  • the wood flakes are prepared so that the grain direction is generally parallel to the major longitudinal axis thereof and the flakes are oriented or aligned during mat formation so that their planes are coextensive or generally parallel to each other and at least a majotity, preferably 90% or more, have their grain direction aligned with a predetermined axis of the structural member.
  • the grain direction of the flakes is aligned with the longitudinal axis of the structural members.
  • the wood flakes can be prepared by various conventional techniques. For example, pulpwood grade logs or so-called roundwood, can be converted into flakes in one operation with a conventional roundwood flaker. Alternatively, logs, logging residue with a total tree can be cut into fingerlings in the order of 0.5 to 3.5 inches long with a conventional device, such as the helical comminuting shear disclosed in U.S. Patent 4,053,004, and the fingerlings flaked in a conventional ring-type flaker. The woods preferably are debarked prior to flaking.
  • Roundwood flakes generally are preferred because the lengths and thickness can be more accurately controlled and the width and shape are more uniform. Also, roundwood flakes tend to be somewhat flatter which facilitates their alignment during mat formation. Roundwood flakes generally produce lesser amounts of . undesirable fines.
  • wood flakes should have an average length of about 0.5 inch to about 3.5 inches, preferably about 1 inch to about 2 inches, and an average thickness of about 0.01 to about 0.05, preferably about 0.015 Co about 0.025 inch and most preferably about 0.02 inch. Flakes longer than about 3.5 inches tend to curl which hinders proper alignment during mat formation and it is difficult to insure that flakes shorter than about 0.5 inch do not become aligned with their grain direction cross-wise. Flakes thinner than about 0.01 inch tend to require excessive amounts of binder to obtain adequate bonding and flakes thicker than about 0.05 inch are relatively stiff and tend to require excessive compression to obtain the desired intimate contact therebetween. In any given batch, some of the flakes can be shorter than 0.5 inch and some can be longer than 3.5 inches so long as the overall average length is within the above range. The same is true for the thickness.
  • the flakes should have a length which is several times the width, preferably about 4 to about 10 times. Using this constraint as a guide, the average width of the flakes generally should be about 0.1 to about 0.5 inch.
  • the flake size can be controlled to a large degree during the flaking operation, it is usually necessary to use some classification in order to remove undesired particles, both undersized and oversized, and thereby insure the averge length, thickness and width of the flakes are within the desired ranges.
  • Flakes from some green woods can contain up to 90% moisture.
  • the moisture content of the mat must be substantially less for the pressing operation.
  • wood flakes tend to stick together and complicate classification and handling prior to blending.
  • the flakes preferably are dried prior to classification in a conventional dryer to the moisture content desired for the blending step.
  • the moisture content to which the flakes are dried depends primarily on a particular binder used and usually is in the order of about 3 to about 20 weight % or less, based on the dry weight of the flakes.
  • the flakes can be partially dried prior to classification and then dried to the desired moisture content for blending after classification. This two-step drying can reduce overall energy requirements for drying flakes prepared from green woods when substantial quantities of improperly sized flakes must be removed during classification and, thus, need not be as thoroughly dried.
  • a known amount of the dried, classified flakes is introduced into a conventional blender wherein predetermined amounts of a binder, and optionally a wax, a preservative and other additives, is applied to the flakes as they are tumbled or agitated in the blender.
  • Suitable binders include those used in the manufacture of particle board and similar pressed fibrous products and other chemical bonding systems. Resinous particle board binders presently are preferred.
  • Suitable binders include thermosetting resins such as phenol-formaldehyde, resorcinolformaldehyde, melamine-formaldehyde, urea-formaldehyde, urea-furfural and condensed furfuryl alcohol resins, and organic polyisocyanates including those curable at room temperatures, either alone or combined with urea or melamine-formaldehyde resins.
  • thermosetting resins such as phenol-formaldehyde, resorcinolformaldehyde, melamine-formaldehyde, urea-formaldehyde, urea-furfural and condensed furfuryl alcohol resins
  • organic polyisocyanates including those curable at room temperatures, either alone or combined with urea or melamine-formaldehyde resins.
  • Particularly suitable polyisocyanates are those containing at least two active isocyanate groups per molecule, including diphenylmethane diisocyanates, m- and p-phenylene diisocyanates, chlorophenylene diisocyanates, toluene di- and triisocyanates, triphenylmethane triisocyanates, diphenyl ether-2,4,4'-triisocyanate, polyphenol- polyisocyanates, particulatly.diphenyl-methane-4,4'-diisocyanate.
  • binder The particular type binder used depends primarily upon the intended use for the structural member. For instance, structural members made with urea-formaldehyde resins have sufficient moisture durability for many uses which involve minimal exposure to moisture, but generally cannot withstand- extended outdoor exposure. Phenol-formaldehyde and melamine-formaldehyde resins provide the structural member with durable properties required for long-term exterior applications. Polyisocyanates, even in lesser amounts, provide greater strengths and resistant to weathering which is comparable to phenol-formaldehyde and melamine-formaldehyde resins. Polyisocyanates can be cured in about the same or less time as urea-formaldehyde resins. However, polyisocyanates are more expensive and may require the use of a mold release agent because of their tendency to stick to metal parts. These factors are balanced against each other when selecting a specific binder to be used.
  • the amount of binder added to the flakes during the blending step depends primarily upon the specific binder used, size, moisture content and type of wood flakes, and the desired properties of the resulting structural member. Generally, the amount of binder added to the flakes is about 5 to about 12 weight %, preferably about 6 to about 10 weight %, as solids based on the dry weight of the flakes.
  • the binder can be admixed with the flakes in either dry or liquid form.
  • the binder preferably is applied by spraying droplets of the binder in liquid form onto the flakes as they are being tumbled or agitated in the blender.
  • Moisture resistance of the structural member can be improved by spraying a liquid wax emulsion onto the flakes during the blending step.
  • the amount of wax added generally is about 0.5 to about 5 weight %, as solids based on the dry weight of the flakes.
  • a preservative for protecting the wood against attacks by decay fungi and insects is added to the wood flakes during or before the blending step. Any preservative which is compatible with the adhesive system be used.
  • Typical for examples include pentachlorophenol, creosote, chromated copper arsenate, ammonical copper arsenate and the like. It has been found that effective amounts of such preservatives, up to about 5 weight %, can be added to the wood flakes without producing an appreciable reduction in the structural strength of the resulting structural member, i.e., the loss in strength is about the same as solid wood treated with the same preservatives.
  • Other additives such as coloring agents, fire retardants and the like may also be added to the flakes during or before the blending step.
  • the binder, wax and other additives can be added separately or in any sequence or in combined form.
  • the moistened mixture of flakes, binder, wax, preservative, etc. or furnish from the blending step is formed into a loosely-felted, single or multi-layered mat which is compressed into a solid, one-piece structural member, such as structural member 10 illustrated in Fig. 1, or components for assembly of multi-piece structural members, such as the components for structural members 20 and 40 illustrated in Figs. 2 and 3.
  • the moisture content of the furnish after completion of blending should be about 5 to about 25 weight %, preferably about 10 to about 20 weight %.
  • the furnish is formed by suitable apparatus into a generally flat, loosely-felted mat, either single or multiple layers, and the mat is placed in a suitable press wherein it is compressed to consolidate the wood flakes into a structural member of the desired size and cross-sectional shape.
  • the furnish can be deposited on a plate-like carriage carried on an endless belt or conveyor from one or more hoppers spaced above the belt in the direction of travel.
  • a plurality of hoppers is used with each having a dispensing or forming head extending across the width of the carriage for successively depositing a separate layer of the furnish as the carriage is moved beneath the forming heads.
  • the mat In order to produce structural members having the desired strength characteristics, the mat should have a substantially uniform thickness and the flakes aligned during mat formation with the orientation discussed above.
  • the mat thickness can be controlled primarily by appropriately metering the flow of furnish from the forming head.
  • the fLakes can be aligned by using a laterally spaced baffling system or other suitable means located between the former heads and the carriage and arranged to guide the elongated flakes into the desired orientation as they are deposited on the carriage or previously deposited layer(s) of furnish.
  • the mat thickness will vary depending upon such factors as the size and shape of the wood flakes, the particular technique used in forming the mat, the desired thickness and density of the structural member or component and the pressing pressure used.
  • the mat thickness usually is about 5 to 6 times the final thickness of the structural member or component. For example, for a structural component having a 1-inch thickness and a density of about 40 lbs./ft. 3 , the mat usually will be about 5-6 inches thick. If the mat is thicker than about 25-30 inches, it usually must be partially pre-compressed to a reduced thickness, with rollers or the like, prior to introduction into the press.
  • Pressing temperatures, pressures and times vary widely depending on the thickness and the desired density of the structural member or component, size and type of wood flakes, moisture content of the flakes and the type of binder.
  • the pressing temperature used is sufficient to at least partially cure the binder and expel water from the mat within a reasonable time period and without charring the wood.
  • a pressing temperature ranging from ambient (for room temperature- curable binders) up to about 450°F can be used. Temperatures above 450°F can cause charring of the wood flakes.
  • a pressing temperature of about 250 to about 375°F is generally preferred for polyisocyanate binders which does employ a catalyst and a temperature of about 350 to about 425°F is generally preferred for phenolformaldehyde resin binders.
  • the pressure should be sufficient to press the wood flakes into intimate contact with each other without crushing them to the point causing a breakdown of fibers with a resultant degradation in structural integrity.
  • the pressure usually is about 325 to about 500 psi.
  • the pressing time is sufficient to at least partially cure the binder to a point where the structural member or component has sufficient integrity for handling.
  • the press cycle typically is about 2 to about 20 minutes; however, longer times can be used when pressure-curing binders are employed or when more complete curing of thermosetting binders is desired.

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Forests & Forestry (AREA)
  • Dry Formation Of Fiberboard And The Like (AREA)
EP80106370A 1980-10-20 1980-10-20 Verfahren zum Herstellen von Bauteilen aus zusammengesetztem Holzmaterial Expired EP0050164B1 (de)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE8080106370T DE3071187D1 (en) 1980-10-20 1980-10-20 Method of manufacturing structural members of composit wood material
EP80106370A EP0050164B1 (de) 1980-10-20 1980-10-20 Verfahren zum Herstellen von Bauteilen aus zusammengesetztem Holzmaterial

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP80106370A EP0050164B1 (de) 1980-10-20 1980-10-20 Verfahren zum Herstellen von Bauteilen aus zusammengesetztem Holzmaterial

Publications (2)

Publication Number Publication Date
EP0050164A1 true EP0050164A1 (de) 1982-04-28
EP0050164B1 EP0050164B1 (de) 1985-10-16

Family

ID=8186848

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80106370A Expired EP0050164B1 (de) 1980-10-20 1980-10-20 Verfahren zum Herstellen von Bauteilen aus zusammengesetztem Holzmaterial

Country Status (2)

Country Link
EP (1) EP0050164B1 (de)
DE (1) DE3071187D1 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0086899A1 (de) * 1982-01-29 1983-08-31 Anton Heggenstaller Verfahren und Vorrichtung zum Formpressen eines Formkörpers, insbesondere zur Bildung einer ein- oder mehrteiligen Palette, eines Tragriegels oder eines tragfähigen Balkenprofiles
EP0092298A1 (de) * 1982-01-25 1983-10-26 Marian B. Greer Verfahren zur Herstellung eines Komposit-Materials
DE19952903A1 (de) * 1999-11-03 2001-05-10 Wolfram Klingsch Holzbauteil für Gebäude oder Bauwerke

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH283661A (fr) * 1949-06-28 1952-06-30 Ferran Jose Pradell Procédé pour l'obtention d'éléments composés en bois pour la construction.
US3164511A (en) * 1963-10-31 1965-01-05 Elmendorf Armin Oriented strand board
CH533213A (fr) * 1969-07-14 1973-01-31 Formige Pierre Procédé de fabrication d'un élément de construction et élément obtenu par ce procédé
DE2307459A1 (de) * 1972-02-29 1973-09-13 Tor Noldus Nilsen Zusammengesetztes bauprofil, umfassend flansche und stege aus separaten teilen
US4195462A (en) * 1975-03-14 1980-04-01 Wood I Systems, Inc. Fabricated wood structural member
DE2831039A1 (de) * 1978-07-14 1980-01-24 John Adam Holman Brett aus kuenstlichem holz, insbesondere fuer bauzwecke, und verfahren zu seiner herstellung

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0092298A1 (de) * 1982-01-25 1983-10-26 Marian B. Greer Verfahren zur Herstellung eines Komposit-Materials
EP0086899A1 (de) * 1982-01-29 1983-08-31 Anton Heggenstaller Verfahren und Vorrichtung zum Formpressen eines Formkörpers, insbesondere zur Bildung einer ein- oder mehrteiligen Palette, eines Tragriegels oder eines tragfähigen Balkenprofiles
US4559195A (en) * 1982-01-29 1985-12-17 Anton Heggenstaller Pressed-material pallet cleat and method and mold for making same
DE19952903A1 (de) * 1999-11-03 2001-05-10 Wolfram Klingsch Holzbauteil für Gebäude oder Bauwerke
DE19952903B4 (de) * 1999-11-03 2012-04-26 Wolfram Klingsch Holzbauteil für Gebäude oder Bauwerke

Also Published As

Publication number Publication date
EP0050164B1 (de) 1985-10-16
DE3071187D1 (en) 1985-11-21

Similar Documents

Publication Publication Date Title
US4241133A (en) Structural members of composite wood material and process for making same
US5002713A (en) Method for compression molding articles from lignocellulosic materials
CA2406170C (en) Dimensionally stable wood composites and methods for making them
US3919017A (en) Polyisocyanate:formaldehyde binder system for cellulosic materials
US4440708A (en) Method for molding articles having non-planar portions from matted wood flakes
US5217665A (en) Phenol formaldehyde steam pressing of waferboard
US6511567B1 (en) Composite building components and method of making same
EP0049299B1 (de) Aus Holzschnitzeln geformte Artikel, wie z.B. Paletten, und Verfahren zum Formen solcher Artikel
US4337710A (en) Pallets molded from matted wood flakes
US6811731B2 (en) Methods of incorporating phosphate/borate fire retardant formulations into wood based composite products
US20030035921A1 (en) Manufacture of multi-layered board with a unique resin system
Papadopoulos Property comparisons and bonding efficiency of UF and PMDI bonded particleboards as affected by key process variables
US20040028934A1 (en) Methods of incorporating treatment agents into wood based composite products
US3790417A (en) Process for preparing fiberboard having improved dimensional stability
EP1858678A2 (de) Verfahren zur herstellung von holzwerkstoffen
US6569279B1 (en) Method for bonding composite wood products
EP0050164B1 (de) Verfahren zum Herstellen von Bauteilen aus zusammengesetztem Holzmaterial
AU731505B2 (en) Steam pre-heating in oriented strand board production
EP1575744B1 (de) Kombinationswerkstoff sowie verfahren zu seiner herstellung
EP1266730B1 (de) Verfahren zur Herstellung von feuchtebeständigen Span- und mitteldichten Faserplatten (MDF)
AU2004314464A1 (en) Hard wood strand products
CA1151388A (en) Structural members of composite wood material and process for making same
US6635208B2 (en) Method for forming narrow channels in a wood flake article
EP1048424A2 (de) Korkverbundplatte und Verfahren zur Herstellung einer solchen Verbundplatte
JPS5950509B2 (ja) 複合木材材料の構造部材およびその製造法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19810824

AK Designated contracting states

Designated state(s): DE FR GB IT SE

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE FR GB IT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 19851016

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19851030

REF Corresponds to:

Ref document number: 3071187

Country of ref document: DE

Date of ref document: 19851121

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: 732

REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19891025

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19891031

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19891130

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19901020

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19910628

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19910702

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST