EE01233U1 - Method for producing laminate flooring boards with edges following the natural curvature of the wood material - Google Patents

Abstract

Present invention relates to a method of production of laminate floorboards with edges following the natural curvature of the wooden material. By the method a laminate floorboards, comprising veneer, which is glued onto the substrate, having edges, which correspond to the edges of the veneer, are obtained.

Description

TECHNICAL FIELD

The present invention relates to a method for manufacturing laminate floor planks with edges that follow the natural curvature of the wood material.

STATE OF THE ART

Several solutions for manufacturing floor planks or floor tiles or other tiles with edges that follow natural curvature are known from the prior art.

Swiss patent CH698020B1 (Peter Herzog-Schymura, publ. 30.04.2009) describes the production of solid wood panels from a number of adjacent wooden elements, which are joined side by side along the edges of these wooden elements along joint lines that follow the natural curvature of the edges as much as possible. The wooden panel to be produced is, for example, a tabletop, a floor element (i.e. a floorboard) or a flat furniture detail, etc.

European patent application EP2295215A1 (Rudolf Meyer, publ. 16.03.2011) describes a method and device for producing wooden panels from unedged planks. The device includes a detection device, such as a digital camera, with which the unedged planks are scanned and the data is stored in a database, and a calculation device, with which a suitable cutting line is calculated for an adjacent curved-edged plank based on the data stored in the database. The device also has a cutting device for cutting out the cutting lines and a corresponding processing station for joining the cut-out boards into panels.

German utility model DE29812919U1 (Willi Schmidt, publ. 17.12.1998) discloses panels made of several planks with curved edges, where in the case of two adjacent planks, one plank has a tongue and groove on the edge of the other plank.

From German patent application DE102007006631A1 (Dieter Karsten Herrmann, publ.

16.08.2007) is known for making floor, wall or ceiling coverings from planks with natural curvature. In this solution, each individual plank is also scanned and the resulting data is stored in a computer database. The data obtained during scanning includes, among other things, a full-size image of the plank. For example, using a CAD program, the images of the scanned planks are placed on the image of the surface of the floor to be covered and the cutting lines of the edges of the adjacent planks are generated either semi-automatically or fully automatically. Each individual plank is cut out using a CNC cutting machine according to the cutting lines.

ESSENCE OF THE INVENTION

The present invention includes a method for producing laminate floor planks with edges that follow the natural curvature of the wood material, comprising the following steps:

in step a) first the material required for the production of laminate floor planks is prepared, for which purpose, when using unedged sawn planks with natural curvature, the shape data of the sawn planks together with the images of the sawn planks are scanned into a computer database, whereby the data includes at least the data of the plank length, width, thickness and edge contours, and the sawn planks are cut lengthwise into plank veneers of the same thickness, or when using plank veneers with natural curvature, the shape data of the plank veneers together with the images of the plank veneers are scanned into a computer database, whereby the data includes at least the data of the plank length, width, thickness and edge contours.

In other words, according to the first preferred embodiment of the invention, in step a) the material required for the production of laminate floor planks is prepared on the basis of unedged sawn planks with natural curvature, for which the shape data of said unedged sawn planks together with the images of the sawn planks are scanned into a computer database, the data containing at least the length, width, thickness and edge contours of the plank, and then said sawn planks are cut longitudinally into plank veneers of the same thickness.

In other words, according to a second preferred embodiment of the invention, in step a) the material required for the manufacture of laminate floor planks is prepared on the basis of plank veneers with naturally curved edges, for which the shape data of the naturally curved unedged plank veneers together with the images of the plank veneers are scanned into a computer database, whereby the data includes at least the length, width, thickness and edge contour data of the plank.

In other words, according to the second preferred embodiment of the invention, in the first step a) instead of unedged sawn planks with natural curvature (according to the first preferred embodiment of the invention), plank veneers are used in step a), which are obtained, for example, from planed veneers cut sequentially from the same log (so-called lamella stack).

According to another preferred embodiment of the invention, the above-listed data additionally includes data on the contours of the bark, heartwood, sapwood and sapwood, and on wood defects.

According to another preferred embodiment of the invention, the computer database stores information about the origin of each plank's supply and other meta-information, such as the presence of an FSC certificate, etc.

Next (step b), a plank veneer pre-layout matrix is generated, which specifies the number of plank veneer rows to cover the floor and the preferred plank veneer width for each row.

In other words, in step b) for the floor surface to be covered (or other surface to be covered), a pre-layout matrix is generated for the selection of plank veneers in different rows on the floor based on the widths of the plank veneers in the computer database (which are derived from the shape data of the scanned sawn planks), which specifies the number of rows of plank veneers to cover the floor and the preferred width of the plank veneers for each row.

One of the tasks of this pre-layout matrix is to ensure that when laying the plank veneers in rows that follow the natural curvature, the rows do not become skewed, which in the worst case would mean that, for example, there would be a different number of plank veneer ends opposite one wall of the room floor and opposite that wall. In other words, this pre-layout matrix limits the direction of the plank veneer rows.

The preferred width or widths are selected according to the existing wood stock of plank veneers.

The actual width distribution, i.e. the widths of the plank veneers in stock (i.e. based on the scanned plank veneer data in the computer database) are divided into different groups (so-called width classes) according to width. In the plank veneer pre-layout matrix, the number of rows of plank veneers covering the floor surface and the width of the rows may also be selected based on technical limitations or technical considerations (for example, the location of doorways, posts, stoves, fireplaces, etc.) or, in addition, the preferences of the designer or client, or, for example, aesthetic preferences.

Whatever considerations are used to determine the number of rows and width preferences in the pre-layout matrix, this defines the technical parameters for the next stage, according to which plank veneers are selected for each row.

Next (step c) based on the shape data of the edge contours of the sawn plank veneers in the computer database, a set of plank veneers with naturally curved edges covering the given floor surface is generated, where when selecting plank veneers for each subsequent row of plank veneers according to the pre-placement matrix, its edge contour is matched to the edge contour of the previous row and to the pre-placement matrix within a given minimum and maximum overlap, and the ends of the plank veneers in each individual row are matched within a given minimum and maximum overlap, and these operations are repeated for each subsequent row of plank veneers until the entire given floor surface is covered.

Then (step d) a common cutting line is generated at the edges of the adjacent plank veneers in the overlap area of each adjacent row of plank veneers, and a common cutting line is generated at the ends of the consecutive plank veneers in the overlap area of the consecutive plank veneers in one row.

Next (step e), a substrate is generated for each plank veneer according to the cutting lines generated in step d), following the shape determined by the cutting lines of its edges and ends, whereby an additional piece of material is added to at least one longer and one shorter edge of the substrate, if necessary, to make a dowel pin.

In a preferred embodiment, in step e), a shape defined by the cutting lines of each plank veneer at its edge and ends is generated according to the cutting lines generated in step d).

the substrate in such a way that the substrate is slightly larger than the cutting lines generated on the plank veneer for the floor plank (i.e. the contour of the substrate is outside the area delimited by the cutting lines generated on the plank veneer), which takes into account, for example, the accuracy tolerances of placing the plank veneer on the substrate, whereby an additional piece of material is added to at least one longer and one shorter edge of the substrate to make a dowel pin, if necessary.

In the next step (step f), a substrate with the shape generated in step e) is cut out for each plank veneer.

Then (step g) the plank veneer and the corresponding cut-out substrate are glued together.

In the preferred embodiment, the veneer and its substrate are placed in the correct position relative to each other, aligned according to the contour of a laser or slide projector, for gluing together. Without this measure, the smaller substrate may end up in the wrong position under the larger lamella.

In the next step (step h), after gluing the plank veneer and its substrate together, the edges of each floor plank are cut so that the edge of the finished floor plank follows the cutting lines of the edges and ends of the plank veneer generated in step d), and a corresponding tongue and groove is cut into the substrate along the cutting lines of the plank veneer on all four edges of the floor plank to join the finished floor planks together along their cutting lines.

Preferably, plywood, fiberboard or laminated wood board is used as the substrate.

In a preferred embodiment of the invention, in step c) the ends of the plank veneers in each individual row are matched to a predetermined minimum and maximum overlap such that the joint between the ends of two plank veneers of the next row is no closer to the joint between the ends of two plank veneers of the previous row than the width of the abutting ends of the plank veneers of the previous row.

A fixed numerical value can also be used for this purpose, which is selected by the operator and which is generally equal to or greater than the average width of the ends of the plank veneers.

The same condition (but with a weaker restriction) also applies to the required minimum distance from the end joint of the plank veneers of the previous row. This prevents the joints of adjacent plank rows from coming too close together.

In a preferred embodiment of the invention, in step a) when scanning a computer database of shape data of unedged sawn planks or veneers with natural curvature, this data includes at least an image of the narrower side of the sawn plank or veneer, and in the most preferred embodiment an image of both sides of the sawn plank or veneer, which allows creating a 3D model and taking into account the edge and heartwood of both sides of the sawn plank or veneer.

Preferably, in step c), the generation of the set of plank veneers and the matching of the edge contours of the plank veneers of the following rows with the edge contours of the previous rows within a predetermined minimum and maximum overlap are performed automatically with the corresponding control program using a computing device (computer or computers).

Preferably, the process of selecting plank veneers into rows of plank veneers, which is automatically performed by the control program, has the possibility of manual intervention and, if necessary, the selection of one or more rows of plank veneers can be performed manually by an operator.

Preferably, the generation of a common cutting line in the edges of adjacent plank veneers in step d) is also performed automatically by means of a computing device (computer or computers) with a corresponding control program.

Preferably, there is a possibility for manual intervention in the process of cutting the veneers automatically performed by the control program and, if necessary, for changing the location and position of the veneers of two or more adjacent rows and for manually correcting the cutting lines of the edges by the operator.

BRIEF DESCRIPTION OF ILLUSTRATIONS

The method according to the invention is described below by way of example with reference to the accompanying schematic drawings, where:

FIG. 1 shows a floor laid from laminate floor planks according to the invention with edges following the natural curvature of the sawn planks;

FIG. 2 shows a pre-positioning matrix;

Figure 3 shows the heartwood (i.e. the outer contour of the sapwood represented by a thin line) and sapwood (inner contour represented by a thick line) contours created in the edges of the plank veneer;

Figure 4 shows the overlap corridors that arise in the overlap area (right in the figure) after three plank veneers (left in the figure) are placed side by side in an overlapping manner;

FIG. 5 shows the formation of a horizontal cutting line (double-dotted-dash line) along the longer side of the plank veneer in overlapping corridors of three plank veneers according to FIG. 4;

FIG 6 shows the formation of a vertical cutting line (double-dotted line) along the shorter side of the plank veneer in the overlap corridors. The left side of FIG 6 shows the contours of the separate plank veneers, which are shown as overlapping plank veneer contours on the right side of FIG 6. In addition, one difference is the free hand straight principle, where the vertical cutting line connecting the shorter sides of the plank veneer is a curved line, which, in order to achieve a natural appearance, gives the impression of a freely drawn straight line at first glance.

EXAMPLE OF IMPLEMENTATION OF THE INVENTION

The first step for implementing the first embodiment of the method according to the invention includes a stage of preparing unedged sawn timber, in which the bark is removed from the edges of the sawn timber, the end gaps are graded and the sawn timber is passed through a thicknesser. This is followed by grading and defecting of the sawn timber.

Next, the sawn planks are scanned, as a result of which the shape data of the sawn planks, together with the images of the sawn planks, are scanned into a computer database, whereby the data includes at least the length, width, thickness and edge contours of the plank, in addition to, for example, the contours of the bark, heartwood, sapwood and sapwood, and wood defects.

In addition to each plank, the computer database stores information on the origin of the supply and other metadata, such as the presence of an FSC certificate, etc.

The sawn planks are then cut lengthwise into plank veneers of uniform thickness.

Defect removal of sawn timber can also be done automatically after defects are detected by the scanner.

Each individual sawn log is marked for later identification and then the sawn logs are sorted into bundles, which are in turn marked for later identification.

The sawn timber sorted into bundles is cut, or in other words, sliced lengthwise into veneers or lamellas of uniform thickness. The veneers are marked and stored in bundles, which are also marked.

The first step for implementing the second embodiment of the method according to the invention includes scanning a stack of veneer lamellas, or planks, cut sequentially from the same log. In this case too, the data stored in the computer database during scanning includes at least data on the length, width, thickness and edge contours of the plank, in addition to, for example, data on the contours of the bark, heartwood, sapwood and sapwood, and wood defects.

The perimeter of the floor surface is drawn up, i.e. a predetermined floor surface is defined, which must be covered with plank veneers with naturally curved edges.

This is done on a computer, for example using a CAD program.

Then, additional restrictive parameters are specified, such as the type of wood (oak, maple, etc.), whether or not heartwood can remain on the edges of the plank veneers, the minimum and/or maximum width and/or length of the plank veneer, etc.

Minimum and maximum overlaps for the edges of two adjacent plank veneers and minimum and maximum overlaps for the ends of consecutive plank veneers are also specified. For example, a criterion for the allowable difference in end widths may also be specified.

Then, a distribution model of plank veneer width classes is generated for a given floor area based on the width classes of plank veneers in stock in a computer database or based on other, e.g. aesthetic, parameters.

For this, a so-called pre-placement matrix is formed, which is shown in FIG. 2.

In the next stage, based on the shape data of the edge contours of the sawn plank veneers in the computer database, a set of plank veneers with naturally curved edges covering the floor surface corresponding to the given floor surface is generated.

In doing so, a pre-placement matrix is taken into account, which specifies the primary preferred width of each individual row.

This is preferably done using a suitably adapted CAD program module, i.e. a control program, which searches a computer database for plank veneers that meet the specified narrowing parameters.

When selecting plank veneers for each subsequent row of plank veneers, its edge contour is matched to the edge contour of the previous row by a given minimum and maximum overlap, and the ends of the plank veneers in each individual row are matched by a given minimum and maximum overlap. These operations are again related to the pre-layout matrix, by means of which the preferred width and overlaps at the edges of each row are defined, as mentioned above.

In this stage, the plank veneers are selected and matched in the corresponding row in such a way that the joint between the ends of two plank veneers in the next row is no closer to the joint between the ends of two plank veneers in the previous row than the width of the ends of the abutting plank veneers in the previous row.

A fixed numerical value can also be used for this purpose, which is chosen by the operator, for example, its size is taken as 50 cm. Of course, its value can be any numerical value.

The same condition, but with a weaker restriction, also applies to the required minimum distance from the end joint of the plank veneers of the previous row.

Figure 6 shows the sizes a and b, the distance and width of the cutting lines of the ends, respectively.

These operations are repeated for each subsequent row of plank veneers until the entire specified floor area is covered.

Next, a common cut line is generated at the edges of the adjacent plank veneers in the overlap area of each adjacent row of plank veneers.

A cutting line is also generated in the overlap area of the ends of two consecutive plank veneers in one row.

The resulting set of plank veneers together with the generated cutting lines is displayed to the operator on a computer screen, and preferably, the result of the process of selecting plank veneers in rows of plank veneers, which is automatically performed by the control program, leaves the operator the opportunity to manually intervene and, if necessary, select one or more rows of plank veneers to perform the process manually.

The operator can also manually correct the shape and course of the automatically generated computer-generated cutting lines if necessary. The operator also has the option to correct the position of the cutting line at the ends of two consecutive plank veneers in the same row if necessary.

The possibility of manual operator intervention is necessary to enable the selection of plank veneers with a different shape from a computer database instead of the plank veneers selected by the control program, either based on other technical considerations (for example, doorways on the floor surface, chimneys, beams, etc.) or based on purely aesthetic appearance, in the case of more complex floor surface perimeter shapes.

Once the set of plank veneers with all the cutting lines has been set, the next step is to generate a substrate that follows the shape of each individual plank veneer based on these cutting lines.

In this case, an additional piece of material is added to at least one long and one short edge of the substrate to make a butt joint tenon. All cutting lines for the plank veneers and their substrates are saved for CAM processing.

Next, the substrate material is calibrated, for example by planing it and, if necessary, making compensation grooves on one side.

Then, a substrate is cut out for each plank veneer.

Next, the plank veneers and substrates are glued together by placing the plank veneer and its substrate in the correct position relative to each other, aligned according to the contour of the laser or slide projector.

Once the glue has dried, the edges of each glued plank veneer and its substrate are cut out on a CNC cutting machine according to the previously set cutting lines. In other words, when cutting glued plank veneer and its substrate, the edges of the plank veneer are cut in such a way that the finished floor planks can be assembled on the floor, while when cutting into the substrate part of each floor plank, a tongue is cut on one edge of the plank and a tongue pin on the other edge.

Each finished floorboard is marked.

After the floor plank set is cut, a so-called floor inspection can be carried out by unloading it onto a special tray or the floor of the corresponding production room. This also includes a quality inspection and, if necessary, a so-called post-filling (for example, to level out knots or other gaps that arise during the process).

This is followed by lifting and sanding the floor.

This is followed by wrapping and packing the finished floor planks for transport.

As an alternative, for example, the floorboards can be brushed and oiled for finishing, along with quality control, before being wrapped and packaged.

It will be apparent to a person skilled in the art that the invention is not limited to the described embodiment, but that many other embodiments of the invention are possible within the scope of the appended claims.

As will be clear to those skilled in the art, the invention is not limited to the embodiments described above, but many other embodiments are possible within the scope of the requirements.

Claims (5)

1. A method for producing laminate floorboards with edges following the natural curvature of the sawn boards, characterized in that it comprises the steps of: in step a) the material required for producing laminate floorboards is prepared, for which, when using unedged sawn boards with natural curvature, the shape data of the sawn boards together with the images of the sawn boards are scanned into a computer database, wherein the data includes at least data on the length, width, thickness and edge contours of the board, and the sawn boards are cut lengthwise into plank veneers of uniform thickness, or for which, when using plank veneers with natural curvature, the shape data of the plank veneers together with the images of the plank veneers are scanned into a computer database, wherein the data includes at least data on the length, width, thickness and edge contours of the plank veneer, in step b) a pre-layout matrix of plank veneers is generated by a computer, which specifies the number of rows of plank veneers to cover the floor and the preferred widths of the plank veneers for each row, in step c) based on the shape data of the edge contours of the sawn plank veneers in the computer database, a set of plank veneers with natural curved edges covering the floor surface corresponding to the given floor surface is generated by the computer, where when selecting plank veneers for each subsequent row of plank veneers according to the pre-placement matrix, its edge contour is matched to the edge contour of the previous row and to the extent of the pre-placement matrix, as well as the ends of the plank veneers in each individual row are matched to the extent of the pre-positioned minimum and maximum overlap, and the said operations are repeated for each subsequent row of plank veneers until the entire given floor surface is covered, in step d) a common cutting line is generated by the computer in the overlap area of each adjacent row of plank veneers, as well as a common cutting line is generated in the overlap area of the ends of two consecutive plank veneers in one row, in step e) according to the cutting lines generated in step d) above, a substrate following the shape determined by the cutting lines of its edges and ends, with an additional material part added to at least one longer and one shorter edge of the substrate to make a tongue-and-groove tenon, in step f) a substrate with the shape generated in step e) is cut out for each plank veneer, in step g) the plank veneer and the corresponding cut-out substrate are glued together, in step h) after gluing the plank veneer and its substrate, the edges of each floor plank are cut in such a way that the edge of the plank veneer at the edges of the finished floor plank follows the cutting lines of the edges and ends of the plank veneer generated in step d) and a corresponding tongue-and-groove tenon following the cutting lines of the plank veneer is cut into the longer edges of the substrate for self-joining the finished floor planks along their cutting lines. 2. The method according to the preceding claim, characterized in that plywood, fiberboard or laminated wood board is used as the substrate. 3. A method according to any preceding claim, characterized in that in step c) the ends of the plank veneers in each individual row are matched within a predetermined minimum and maximum overlap such that the joint between the ends of two plank veneers of the next row is no closer to the joint between the ends of two plank veneers of the previous row than the width of the abutting ends of the plank veneers of the previous row. 4. The method according to any preceding claim, characterized in that in step a) when scanning the shape data of unedged sawn planks with natural curvature together with the images of the sawn planks and storing them in a computer database, said data includes at least data on the length, width, thickness and edge contours of the plank, in addition to data on the contours of the bark, heartwood, sapwood and sapwood and wood defects. 5. The method according to any preceding claim, characterized in that in step a) when scanning the shape data of the naturally curved plank veneers together with the images of the plank veneers and storing them in a computer database, said data includes at least data on the length, width, thickness and edge contours of the plank veneer, in addition to data on the contours of the bark, heartwood, sapwood and sapwood and wood defects.