Method for producing laminate floorboards having edges following the natural curvature of the wooden material

Abstract

The present invention relates to a method for producing laminate floorboards having edges following the natural curvature of veneer planks cut from timber planks with natural curvature. With the method laminate floorboards are obtained, each floorboard comprising a veneer plank glued onto a substrate, the contour of the substrate and the veneer corresponding with each other.

Claims

1. A method for producing a laminate floorboard with edges following the natural curvature of timber planks, the method comprising: in step a) scanning contour data and images of the timber planks into a computer database, wherein unedged timber planks having natural edge curvature are used, said data comprising at least the length, width, thickness, and edge contours of the timber planks and step a) further comprises cutting the timber planks lengthwise into veneer planks having equal thickness, in step b) generating a preliminary layout array of the veneer planks defining a number of rows of veneer planks to cover a floor area and a preferred width of the veneer planks for each row, in step c) generating on the basis of the contour data of the edges of the veneer planks a set of veneer planks with edges having natural curvature for covering the floor area, wherein the edge contour of each row of veneer planks is matched with the edge contour of a previous row according to a minimal and maximum overlap determined by the preliminary layout array, and wherein ends of the veneer planks in each row are matched according to the minimal and maximum overlap, in step d) generating a common cutting line on the edges of adjacent veneer planks in an overlap area of each adjacent row of veneer planks while the adjacent veneer planks are disposed adjacently in an overlapping manner, and generating a cutting line on the ends of the veneer planks in each row of veneer planks in an overlap area of the ends of two consecutive veneer planks, in step e) generating for each veneer plank a substrate that follows the contours of the veneer plank determined by the cutting lines on the edges and the ends of the veneer plank, and adding an additional material into at least one longer edge and at least one shorter edge of the substrate for forming a tongue-and-groove joint, in step f) cutting a substrate for each veneer plank having the shape generated in step e), in step g) gluing together each veneer plank and the corresponding cut-out substrate to create the laminate floorboard, and in step h) cutting the edges of each laminate floorboard so that the edges of the veneer plank follow the cutting lines on the edges and ends generated in step d) and cutting into the longer edges of the substrate a corresponding tongue and groove following the cutting line of the substrate for mutual joining of laminate floorboards along their cutting lines.

2. The method according to claim 1, wherein plywood, fibreboard, or chipboard are used as the substrate.

3. The method according to claim 1, wherein in step c) in each row the ends of the veneer planks are matched according to the minimal and maximum overlap so that a junction of the ends of the veneer planks in a next row is not closer to a junction of the ends of the veneer planks in a previous row than a width of butting ends of the previous row of the veneer planks.

4. The method according to claim 1, wherein in step a) said data further comprises the contour of bark, pith, heartwood, and wane of the timber planks and wood defects.

5. The method according to claim 1, wherein in step a) the length, width, thickness and contour of the timber planks includes bark, pith, heartwood, wane, and defects of the timber planks.

6. The method according to claim 1, wherein veneer planks having natural edge curvature are used in step a) and step a) comprises scanning the contour data and images of the veneer planks into the computer database, said data comprising at least the length, width, thickness, and edge contours of the veneer planks.

7. The method according to claim 1, wherein step b) is repeated for every row of veneer planks until the floor area is covered.

8. The method according to claim 1, wherein each of the timber planks cut lengthwise in step (a) comprises a sapwood region around a periphery of the timber plank and a heartwood region disposed within the sapwood region, and wherein the cutting lines generated in step (d) is within an overlap region where respective heartwood regions of adjacent veneer planks overlap.

9. A method for producing laminate floorboards with edges following the natural curvature of timber planks, the method comprising: scanning contour data of at least the length, width, thickness, and edge contours of timber planks into a computer database, generating a set of digital timber planks with edges having natural curvature for covering a floor area, wherein the edge contour of each row of timber planks is matched with the edge contour of a previous row according to a minimal and maximum overlap determined by a preliminary layout array, and wherein ends of the timber planks in each row are matched according to the minimal and maximum overlap, generating a common cutting line on the edges of adjacent digital timber planks in an overlap area of each adjacent row of timber planks while the adjacent digital timber planks are disposed adjacently in an overlapping manner, and generating a common cutting line on the ends of the timber planks in each row of timber planks in an overlap area of the ends of two consecutive timber planks, cutting the edges of each timber plank so that the edges of the timber plank follow the cutting lines on the edges and ends.

10. The method according to claim 9 further comprising, prior to the step of generating a common cutting line, generating a preliminary layout array of the timber planks defining a number of rows of timber planks to cover a floor area and a preferred width of the timber planks for each row based on an inventory status of the timber planks in the computer database according to at least one parameter comprising width classes of the timber planks and aesthetic parameter of the timber planks.

11. The method according to claim 9, wherein each of the timber planks cut lengthwise comprises a sapwood region around a periphery of the timber plank and a heartwood region disposed within the sapwood region, and wherein the cutting lines generated are within an overlap region in which respective heartwood regions of adjacent veneer planks overlap.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Next the method according to the present invention is described with the help of the exemplary embodiment with references to the attached schematic drawings, where:

(2) FIG. 1 shows a floor covered according to the invention by the laminate floorboards with the edges following natural curvature of the timber planks;

(3) FIG. 2 shows a preliminary layout array;

(4) FIG. 3 shows a veneer plank having at the edges contours of the pith (i.e. the outer contour of sapwood shown by a thin line) and heartwood (the inner contour shown by a thick line);

(5) FIG. 4 shows three veneer planks (on the left) which after being placed adjacently in an overlapping manner (on the right) create overlap areas;

(6) FIG. 5 shows formation of the horizontal cutting line (double point dashed line) into an overlap area of three adjacent veneer planks according to FIG. 4 at their longer edges;

(7) FIG. 6 shows formation of the vertical cutting line (double point dashed line) along the shorter edge into an overlap area of veneer planks. The contours of veneer planks are shown separately on the left of FIG. 6 whereas on the right of FIG. 6 these are shown as overlapping contours of veneer planks. Additionally a free-hand-straight principle can be seen as a characteristic feature, when the cutting line connecting the shorter sides of the veneer planks is a curve, which at first glance looks like a freely maid straight line to achieve a natural look.

MODE(S) FOR CARRYING OUT THE INVENTION

(8) First step for implementing the method according to the first embodiment of the invention comprises a step for preparing the unedged timber planks, which involves removing bark from the edges of the timber planks, crosscutting the split ends and feeding timber planks through a thicknessing machine, to be followed by crosscutting and rejecting of the timber planks on the basis of defects.

(9) Next the contour data with the images of the timber planks are scanned into the computer database, comprising at least the data of the length, width, thickness and edge contours of the plank, additionally, for example, data about bark, pith, heartwood and wane contours as well as wood defects.

(10) Delivery and origin information and other metadata for instance the existence of FSC certificate etc. for every single plank are also stored in the computer database.

(11) Then timber planks are cut lengthwise into veneer planks in equal thickness.

(12) Rejection of defective timber planks can be implemented automatically after the defects have been identified by the scanner.

(13) Every single timber plank is labelled for later identification whereupon these are sorted into bunches, which also are labelled for later identification.

(14) The timber planks sorted in bunches are cut, in other words they are sliced lengthwise into veneer planks or lamellae in equal thickness. Veneer planks are labelled and stored as bunches, which are also labelled.

(15) A first step for implementing the method according to the second embodiment of the invention comprises scanning of veneer lamellae or in other words veneer planks sliced consecutively from the same trunk. In this case the scanned data stored into the computer database also comprises at least the data of the length, width, thickness and edge contours of the plank, additionally for example data about bark, pith, heartwood and wane contours and wood defects.

(16) The perimeter of the floor area is recorded, that is the floor area to be covered with veneer planks with the edges following natural curvature is defined.

(17) This is done in a computer with the help of the CAD program, for example.

(18) Then additional limiting parameters are specified, such as a type of wood (oak, maple, etc.), whether the pith wood is allowed at the edges of the veneer planks or not, the minimal and/or maximum width and/or length of a veneer plank, etc.

(19) Also the minimal and maximum overlap of the edges of two adjacent veneer planks and minimal and maximum overlap of the ends of two consecutive veneer planks are specified. The allowed difference between the widths of the ends can also be specified, for instance.

(20) Subsequently a distribution model according to width classes of the veneer planks for the predetermined floor area is generated on the basis of the inventory status of the veneer planks in the computer database according to their width classes or on the basis of other parameters, for instance on aesthetic parameters.

(21) For this purpose a so-called preliminary layout array is formed, which is shown on FIG. 2.

(22) In the next step on the basis of the edge contour data of the veneer planks of the timber planks in the computer database, for covering the predetermined floor area, a set of veneer planks with the edges following natural curvature is generated.

(23) In doing so, a preliminary layout array is taken into account, specifying a preferred initial width for every row.

(24) This is implemented with the help of the customized CAD program module, i.e. a control program, which searches from the computer database the veneer planks which correspond to the predetermined limiting parameters.

(25) When selecting veneer planks for every next row, the edge contour of the given row is matched with the edge contour of the previous row according to the predetermined minimum as well as maximum overlap and every single row ends of the veneer planks are matched according to the predetermined minimum as well as maximum overlap. Those operations are related with the preliminary layout array, which specifies, as mentioned above, for every single row its preferred width and overlap at the edges.

(26) In this step the selection and matching of veneer planks for the corresponding row is performed so that the end joint of two veneer planks in the next row is not closer than the width of the butting ends of the veneer planks in the previous row.

(27) For this purpose a fixed value of variable can be used, which is selected by the operator, this could be 50 cm, for instance, or any other numerical value.

(28) Same criterion with less strict limitation applies to the required distance from the end joint of two veneer planks in the row before the previous row.

(29) FIG. 6 shows values a and b, which indicate the distance and width of the cutting lines respectively.

(30) Said operations are repeated for every next row of the veneer planks until the whole floor area is covered.

(31) Next for every overlap area of the adjacent veneer planks on the edges of adjacent veneer planks a common cutting line is generated.

(32) For the overlap area of the ends of two subsequent veneer planks in the same row a common cutting line is also generated.

(33) The acquired set of veneer planks with the cutting lines generated is displayed for the operator on the screen who preferably has an option to intervene manually in the results of the automatic selection process of veneer planks for the rows and when required, for one or more rows make the selection of veneer planks for the process manually.

(34) If need be, the operator can also manually correct the shape and path of the automatically generated cutting lines. When required, the operator can also manually correct the position of cutting line of the ends of two subsequent veneer planks in the same row.

(35) The opportunity of manual intervention by the operator is necessary to enable in case of a more complex shape of the floor perimeter to choose veneer planks with a different shape instead of the veneer planks selected automatically by the control program either for the purpose of other technical considerations (for example the position of the door openings, chimneys, posts, etc.) or for purely aesthetic aspect.

(36) When the set of veneer planks with all the cutting lines is determined, next for every single veneer plank substrate is generated in the shape corresponding to the cutting lines of the veneer plank.

(37) Thereby for forming a tongue-and-groove joint an additional material portion is added at least into one longer edge and into one shorter edge of the substrate. All the cutting lines for the veneer planks and for their substrates are stored for CAM processing.

(38) Thereafter the substrate material is calibrated, for example, by planing and to one side of the substrate a compensating groove is made when needed.

(39) After that for every veneer plank a substrate is cut out.

(40) The corresponding veneer planks and substrates are subsequently glued together by placing a veneer plank and its substrate in the correct position in relation to each other with the help of the contour from the laser or image projector.

(41) When glue has set, the edges of every single veneer plank and its substrate glued together is cut in the CNC cutting machine according to the previously determined cutting lines. In other words, the edges of a veneer plank and its substrate glued together are cut in such a way that the obtained floorboards are ready to be assembled on the floor, and in the course cutting of the substrate part of every floorboard into one edge of the substrate a tongue and into the other edge a groove is cut.

(42) Every ready floorboard is labelled.

(43) After the set of floorboards has been cut and ready, optionally a so-called floor inspection is performed by laying floorboards on a special base or on the floor of the corresponding manufacturing space. Simultaneously a quality checking and when needed also so-called post-puttying is performed (for example to smooth knot spots or other gaps revealed in the process).

(44) Thereafter the laid floor is disassembled and polished.

(45) This is followed by wrapping ready floorboards into the plastic film and packaging for transport.

(46) Optionally, prior to wrapping by film and packaging, in order to touch up the floorboards, brushing and oiling thereof along with a quality checking takes place.

(47) It is obvious to the person skilled in the art that the invention is not limited to the exemplary embodiments described above, but within the scope of the attached claims many other embodiments of the inventions are conceivable.

(48) It is clear to the person skilled in the art that the invention is not limited to the exemplary embodiments described above, but within the scope of the attached claims many other embodiments of the inventions are possible.