Classifications

• • 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
  • E04C2/30—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by the shape or structure
  • E04C2/34—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by the shape or structure composed of two or more spaced sheet-like parts
• • 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
  • B27N5/02—Hollow articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D24/00—Producing articles with hollow walls
  • B29D24/002—Producing articles with hollow walls formed with structures, e.g. cores placed between two plates or sheets, e.g. partially filled
  • B29D24/004—Producing articles with hollow walls formed with structures, e.g. cores placed between two plates or sheets, e.g. partially filled the structure having vertical or oblique ribs

Definitions

• the invention relates to a method for manufacturing structures, especially for manufacturing boards, having at least one, preferably a multiple of adjacent hollow longitudinal channels arranged between outer board portions.
• Said method comprises the steps of providing a compressible and suitably curable matrix material between outer press panels and arranging, for each hollow channel, a separate core press expander means into said curable matrix material, and further expanding said core press expander elements to correspond to the final sectional dimensions of said channels while compressing said press panels to obtain the final outer dimensions of said structure, i.e. said board.
• the invention also relates to an apparatus for the manufacturing of a board made of a compressible matrix material and having one or preferably several adjacent, essentially longitudinal channels therein, said apparatus comprising an arrangement of outer press panels as well as channel core press expander means located there between, said core press expander means comprising wall portions which are movable outwards in an essentially parallel disposition with respect to a central axis of said expander means, for compressing said matrix material to the final dimensions of said board.
• Hollow channel cement flake boards are excellent for many structural purposes, but in some case there is a demand for a wood based material which is easier e.g. to cut and fix together using normal carpenter's tools and methods. Therefore wood chip boards of all kinds have their established position among carpenters and other craftsmen.
• a common wood chip board comprises a mix of wood chips and a glue agent, and this matrix material is compressed between hot press panels to form a board having generally smooth opposite surfaces, the interior of said board being more or less compressed and coherent.
• the glue used for the production of wood chip board was earlier generally a formaldehyde based glue agent which was cured by heating, but nowadays less harmful glue components are used for the same purpose.
• Normally such wood fiber boards will have a thickness of 6 to 32 millimeters. Thicker boards constitute a problem since it is difficult to direct the impact of opposite press panels into the central portions of a relatively thick board, and thus a thick board will become structurally instable due to ins * - ⁇ fficient compression and bonding between the wood chips in the central portion of said board.
• the purpose of the present invention is to widen the range of board types by introducing a wood chip board having hollow channels extending in the longitudinal direction between said opposite board surfaces.
• This also and especially includes boards having a relatively long distance between said opposite board surfaces, say e.g. 100 to 300 millimeters.
• the object of the invention is achieved by using a method and an apparatus as described in the appended claims.
• the in ⁇ vention generally comprises a modification of the arrangement described the above mentioned said Finnish patent application so that a glue agent is used instead of said cement based binding agent, and by introducing heating means for rapidly curing said glue agent while compressing said matrix material to the final shape of said board.
• said curable matrix material comprises a heat curable glue agent and said method further com- prises the providing of a heat impact to said glue agent, for rapidly curing said glue agent prior to the removal of said core press expander means .
• Figure 1 shows a schematic view of an arrangement in accordance of one embodiment of the invention
• Figure 2 shows a sectional view of a board manufactured in an alternative embodiment, wherein the core press expanders have a triangular cross section
• FIG 3 shows one embodiment of a core press expander means for making triangular hollow portions in accordance with Figure 2
• Figure 4 shows how the core press expander means according to Figure 3 is located within the matrix material prior to extracting said expander from a manufactured board
• Figure 5 shows an alternative embodiment of a core press expander means
• Figure 6 shows the core press expander means in a retracted position within the matrix material.
• the inventive arrangement generally comprises a lower press element 1, an upper press element 2, and, suitably, side press elements 3, 3a, for pressing, between the surfaces of said elements 1, 2, 3 and 3a, a curable matrix material 4 to form a hollow core board 5.
• Figure 1 further generally discloses multiple adjacent core press expanders 6, 6a arranged within said matrix 4 to form, upon consolidation of said curable matrix material , hollow core portions 7, 8 extending essentially longitudinally through said board 5 (see also Figure 2 ⁇ .
• FIG. 1 comprises hollow core portions or channels of a generally rectangular sectional shape.
• An especially favorable embodiment of the invention comprises hollow channels 7, 8 having a generally triangular sectional shape, as disclosed in Figure 2.
• This triangular channel shape gives intermediate wall portions 9, 10 which are in pairs, respectively, inclined. The inclination of said wall portions 9, 10 actually gives the board an exceptionally high resistance against shearing, and thus such a board can advantageously be used for numerous structural purposes.
• said curable matrix comprises a basic material, which favorably is constituted of wood chips or the like material which preferably can be relatively easily worked with hand tools.
• a heat curable glue agent is mixed into said basic material and thereafter cured so as to form, with said basic material, a coherent material.
• the inventive curing procedure thus comprises the step of heating the glue and/or the basic matrix to a considerably high temperature, while simultaneously applying pressure to said matrix material, for bringing said wood chips or the like into a close mutual contact and simultaneously compressing said material to its final shape.
• the pressure is normally obtained by moving said upper press panel 2 towards said lower press panel 1.
• the press force generally corresponds to the forces normally used for manufacturing wood fiber boards.
• the reference to 'upper' and 'lower', respectively, is intended only to be a simplifying statement for better understanding of Figure 1, and in some embodiments the main press panels may actually be arranged and orientated in a different manner, for example vertically.
• said upper press panel 2 favorably is pressed towards said lower press panel 1 until it reaches side press panels 3, 3a. At this stage said side press panels 3, 3a are moved inwards to form, between them, the edge portion of said board 5.
• said board edges favorably comprise groove and tongue formations 11, 12 as known per se .
• the inner portion of said board obtains its hollow core structure using adjacent core press expander elements 6, 6a as known per se from said Finnish patent application No. 943519, but differing from said application the curing procedure now comprises heating at least said matrix material 4 to a considerably high temperature, for rapidly curing said glue agent interconnecting said wood chips.
• the heat applied would be in the range of 100 to 200 °C, preferably about 180 to 190 °C.
• the heat can be applied in different manners, most of which actually also comprise a heating of at least the surface portions of some of said press means 1, 2, 3, 3a and 6, 6a. Said heating should be applied essentially simultaneously with said pressing.
• the procedure actually is very rapid, usually about 5 to 10 seconds, favorably about 8 seconds, for each sectional millimeter of wall material.
• a board having comparatively thick wall portions i.e. a wall thickness of 32 millimeters, would demand a heating/pressing time only of about 3 minutes.
• one embodiment comprises heating means arranged in each of said press elements 1, 2, 3, 3a and 6, 6a.
• Said heating means are generally indicated by reference number 13 and may comprise electrical heating means, hot air blowing means or steam heating means or the like.
• One problem with the heating of only said pressure means 1, 2, 3, 3a and 6 is that external heating applied to said matrix material 4 also tends to dry up the matrix material and thus affect the consolidation of said glue agent in an unfavorable manner. Therefore an embodiment is preferred, wherein the necessary heat is applied by actually blowing a hot f--uid, for example hot air or steam, preferably supersaturated steam, into and preferably through said matrix material 4. This can be done, until the glue agent has set, suitably by pressing said fluid though the inner portions of at least every second core press expander 6 and suitably by retracting said fluid via the outer press elements and e.g. via the intermediate every second core press expanders 6a.
• said temperature can be kept at a high level, while simultaneously enabling the adding of a liquid, e.g. water or an activating agent necessary for the consolidation process of the glue agent .
• a liquid e.g. water or an activating agent necessary for the consolidation process of the glue agent .
• said matrix material constitutes, at the beginning of the process, mainly wood chips or the like easily compressible base material, while components vital for curing the glue agent, in certain embodiments even at least some components of the actual glue agent itself, is fed into said matrix material in connection with said heating fluid.
• Figures 3 to 6 show examples of embodiments of core press expanders used for small diameter core channels.
• the main interest resides not actually in a high pressing force but in an easy contractibility of said expander from said hollow core channel after the consolidation of the board material.
• Figure 3 discloses a triangular core press expander element comprising wedge means 14, 15 which interact with wall elements 16 and corner wedges 17.
• FIG. 3 further discloses channels 18 connecting the interior of said core expander element with the outside thereof. A fluid which is pressed into said interior, or extracted therefrom, will then pass through said channels 18. Since an absolute smoothness of the interior wall of the small size longitudinal hollow core channels 7, 8 of a board 5 usually is of minor importance there are, in accordance with one embodiment of the invention, generally longitudinal distribution channels 19 arranged at the outermost surface of said core press element.
• a central wedge beam 20 favorably also comprises a central bore and channels 21 interconnecting said bore to a space 22 between said wedges and said wall elements 16.
• Figure 4 shows the core press of Figure 3 as positioned in a matrix material 4.
• the core press is shown in a contracted state and ready for withdrawal from the board 5.
• This stage of the procedure appears when said matrix material 4 has been consolidated.
• said central wedge beam 20 has been moved longitudinally with respect to the general extent of the core press expander.
• the outermost parts are retracted from the inner walls constituting the hollow core portion 7, 8 of said board 5, as can be seen in the Figure.
• the retraction is facilitated by counter wedge means located suitably in connection with said wedges 15.
• the core press element disclosed in Figure 5 comprises, on the other hand, collapsible wall portions 23 which are interconnected via hinge means 24, 25 arranged at the corners and in the middle of the wall field. Said wall portions are slightly tiltable due to central rotatable eccentric means 26 acting e.g. directly on the inner surfaces of said wall portions 23, while flexible pushing means 27, for instance spring means or rubber bumpers, force said collapsible wall portions 23 to bend away from the hollow core walls when the eccentric pressing force is removed, thus facilitating the removal of said core press expander.
• This wall portion position is shown in Figure 6.
• Figure 5 discloses one embodiment wherein channels 28 connect the inner portions of the expander with the outer wall surfaces, thus facilitating the passage of heating and/or curing fluid from the inner of the core press expander to the surrounding matrix material, and, in a reverse direction, the passage of an overpressure generated e.g. by an adjacent core press expander into a core press expander having an underpressure. In the corner portions these effects are preferably achieved using generally loose fit hinge structures .
• the fluid is supplied through bores in the outer press panel elements 1, 2, 3 and 3a, the core press expanders acting as suction channels for maintaining underpressure conditions within the matrix material.
• the core press expanders acting as suction channels for maintaining underpressure conditions within the matrix material.
• said core press expanders can favorably be wrapped in a flexible socking made of rubber or the like material, for preventing any matrix material from entering into the press mechanism.
• the whole press apparatus is kept within hot overpressure conditions.
• the inventive concept will produce a quite new type of boards, which as such can be used especially for structural purposes like erecting walls, for floors, ceilings and the like.
• the invention avoids the need of connecting of separate simple two-dimensional boards to form generally three dimensional structures. Still the advantage of easy workability can be maintained .
• the board manufactured in accordance with the invention will also have a special advantage of high strength combined with light weight. Further, the dimensions of the board can be rather freely altered to suit the corresponding purpose. Thus, one favorable embodiment comprises a board which as such has the dimensions and strength directly adapted for a floor structure, the overall thickness being about 300 millimeters. Another board can, on the other hand, show dimensions suitable for general use as a wall element, wherein the thickness can be less than 100 mm.

Landscapes

• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Architecture (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Structural Engineering (AREA)
• Civil Engineering (AREA)
• Wood Science & Technology (AREA)
• Forests & Forestry (AREA)
• Dry Formation Of Fiberboard And The Like (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Laminated Bodies (AREA)
• Panels For Use In Building Construction (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8546424

Family Applications (1)

Country Status (6)

Families Citing this family (6)

Family Cites Families (3)

• 1996
  • 1996-07-23 FI FI962942A patent/FI101054B/fi active IP Right Grant
• 1997
  • 1997-07-23 CN CN 97198141 patent/CN1103846C/zh not_active Expired - Fee Related
  • 1997-07-23 JP JP10506612A patent/JP2000514739A/ja active Pending
  • 1997-07-23 EP EP97930548A patent/EP0914527A1/en not_active Withdrawn
  • 1997-07-23 WO PCT/FI1997/000457 patent/WO1998003747A1/en not_active Application Discontinuation
  • 1997-07-23 AU AU34465/97A patent/AU3446597A/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events