METHOD AND PLANT FOR THE MANUFACTURING OF MATERIAL SHEETS

Description

[0001] The invention relates to a method for producing material plates, in which particles are pressed in a continuous press between two circulating belts under the application of heat to form a composite strand and in which the composite strand emerging from the continuous press is subsequently cut into material plates of the desired size and provided with a profiling process to achieve a non-rectangular material plate cross-section.

[0002] The invention also relates to a plant for producing material plates with a heatable continuous press, a cutting device for producing material plates from a composite strand of pressed particles emerging from the continuous press and a profiling device for achieving a non-rectangular material plate cross-section.

[0003] Material boards primarily refer to wood-based panels that have already been produced in a preferably continuous press and subsequently cut with saws. Examples of suitable materials include particle boards, MDF boards, or OSB boards, whereby the particles mentioned in the introduction are then essentially wood fibers or wood chips that have been provided with a binding agent. More recently, other lignocellulosic materials, such as the fibers of annual plants (e.g., rice straw), have also been used to press material boards. Material boards within the meaning of the invention can also be insulation boards, plasterboards, plastic boards, or other material boards whose particles have been pressed by means of circulating belts in a continuous press with the application of heat. Such a press is marketed by the applicant under the name ContiRoll.Binders are usually added to the particles before the continuous press to ensure the material sheets are highly stable. The composite strand of the aforementioned possible particles produced in this way in the continuous press and emerging from the continuous press is, of course, significantly flat in cross-section due to subsequent cutting processes during the production of material sheets. Typically, the height of the composite strand emerging from the press is less than a hundredth of its width.

[0004] The profiling process referred to in the generic term primarily involves contouring, particularly at the edge of a material plate, which can be achieved using cutting or milling tools. However, within the scope of the invention, profiling is not intended to be limited to the edge.

[0005] This profiling is useful, for example, when the particles in the composite strand emerging from the continuous press straighten up at the edge, resulting in a thicker edge than the center of the composite strand. This leads to problems with subsequent painting or coating with paper or foil. For illustrative purposes, various standardized edge shapes are also known for plasterboards, where the edges are beveled and / or rounded (DIN EN 520).

[0006] But coatings are also common on particleboard and MDF boards. Examples include coatings made of (resin-impregnated) paper, linoleum, or plastic films. The finished boards often have similar edge shapes. Such boards can be found, for example, in the furniture industry, where, depending on customer requirements, such edge shapes are incorporated into the boards using cutting or milling tools.

[0007] Nowadays, however, this always occurs after the material sheets have been completed, after they have largely cooled down. This means that the composite strand, cut into individual sections, is first cooled in large star-shaped mills, such as those known from DE 10 2015 107 376 A1, before the edge profiling is performed. Finally, the material sheet is coated with paper or film in a laminating or laminator, which requires waiting until the profile edge is created. This results in a very lengthy manufacturing process overall.

[0008] WO2004089585A2 discloses the preamble of claim 1.

[0009] The invention aims to simplify the process for producing profiled material panels.

[0010] The problem is solved procedurally by the features of the first claim.

[0011] This results in enormous time savings in the production process of the material sheets. Surprisingly, it was discovered that the profiling of the edges of the composite strand, which will later be cut into material sheets, can be carried out before the material has cooled down. This means that after the dividing cut, the material sheets at least do not have to be re-profiled on the side that was previously the long side of the composite strand. Between the exit point from the continuous press and the profiling unit, there may only be a trimming device to produce the desired sheet width. In this case, the trimming device and the profiling device can be combined into a single processing unit. A profiling module, which is common today, can be eliminated entirely or at least made significantly smaller.

[0012] According to the invention, the profiling process takes place before the material plates have cooled to the average temperature between the temperature of the composite strand at the outlet of the continuous press and the ambient temperature.

[0013] This significantly reduces the size of the system required to produce a material sheet. It has been found that profiling of the composite strand can be carried out without difficulty even at temperatures above the temperature between the exit temperature of the composite strand from the continuous press and the ambient temperature, without causing undesirable stresses to develop later in the material sheets.

[0014] It is preferred if the profiling process is carried out between the exit of the composite strand from the continuous press and a saw for dividing the composite strand into individual sections.

[0015] The individual sections, which often already correspond to the final material sheet size, then already have two profiled edges and no longer need to wait for the cooling process, for example, in a star-shaped mill, before being profiled. The time savings enable either faster production or fewer post-processing machines.

[0016] Preferably, the profiling process comprises a partial round milling of the side edge of the composite strand.

[0017] Partial round milling in particular is much more complex afterwards than if it is carried out directly behind the continuous press or a trimming device.

[0018] It is particularly advantageous if the composite strand is coated on at least one side between the profiling process and the division of the composite strand into individual sections.

[0019] Because the profiling takes place before the composite strand is divided into individual sections, for example on a diagonal circular saw, coating can also be carried out in a way that simplifies the process before the composite strand is divided into individual sections.

[0020] It is even possible for the composite strand to be coated on both sides between the profiling process and the division of the composite strand into individual sections.

[0021] The coating is preferably carried out with a paper or film lamination, wherein the paper or film is connected, in particular glued, to at least one side of the composite strand.

[0022] A side refers to the top or bottom of the flat composite strand. The coating material (paper or film), for example, can be unwound from a roll and pressed onto the respective side. It is then sprayed with an adhesive, for example. The new arrangement of processing steps has the particular advantage that the composite strand is still warm, which can have a very beneficial effect on the bonding process.

[0023] The object is finally achieved in terms of the system by the features of claim 7 and in particular by the fact that the profiling process is carried out by a profiling device which is arranged a maximum of 20 m behind the exit point of the composite strand from the continuous press.

[0024] The advantages are analogous to those of the method according to the invention already described. This ensures that profiling can be carried out very quickly while the composite strand is still warm.

[0025] It is advantageous if only one conveyor track is arranged between the exit point of the composite strand from the continuous press and the profiling device.

[0026] This eliminates or significantly reduces the need for a separate profiling device after dividing the composite strand into individual sections. The profiling device can be combined with the trimming device downstream of the press.

[0027] It is therefore useful if the profiling device is arranged between the exit point of the composite strand from the continuous press and a saw for dividing the composite strand into individual sections.

[0028] It is preferred if the profiling device already includes a rounding cutter.

[0029] For example, if you take the standardized edge of a plasterboard as a basis, this can be produced before the saw.

[0030] This makes it advantageously possible to arrange a coating device between the profiling device and the saw.

[0031] It is preferred if the coating device comprises a one- or two-sided unwinder for papers or films that can be connected to the composite strand as a coating.

[0032] The invention will be explained in more detail below with reference to an exemplary embodiment of the drawings. Fig. 1 a plant for producing a material plate according to the invention in a plan view (for reasons of clarity, a straight transport path in two rows is shown), Fig. 2a side view of the coating device Fig. 1 and Fig. 3 an example of a coated edge profiling Fig. 4 an example of a profiling in the middle area of ​​the composite strand.

[0033] Fig. 1 shows a plant for producing a material plate 1 in a top view. For reasons of clarity, neither the composite strand nor the cut material plate are shown. The deflection arrows indicate that the plant in the upper row continues into the lower row.

[0034] On the left side of the top row, the end of a continuous press 2 can be seen. Such a press, which is marketed by the applicant under the name ContiRoll, is sufficiently well known and needs no further description. Between two rotating press belts, a composite strand is produced by compacting a mat of scattered particles, which are usually moistened with a binder, under pressure and heat. The particles are often lignocellulosic fibers or wood chips, but are not intended to be limited to these within the scope of the invention. The mat emerges compacted as a composite strand at the outlet of the continuous press 2a at a temperature T2 and is transported via a single conveyor track 3 (shown here as a roller conveyor) to a trimming device 4, where uneven edges or the desired width are cut using a trimming cutting tool 5.The composite strand retains its rectangular, flat cross-section up to this point. In a single assembly with the trimming device 4, the profiling device 6 follows, in which, according to the invention, the composite strand is profiled, particularly at the edges, so that the composite strand no longer has a rectangular cross-section. In the exemplary embodiment, a partial rounding cutter 7 is provided for the edge 20. This profiling takes place according to the invention well before the composite strand, which exits the press at a temperature T2, has reached the ambient temperature T1. Spatially, the distance between the press outlet 2a and the profiling device is at least less than 20 m and is always located upstream of a dividing saw, here in the form of a diagonal saw 11.During profiling, the composite strand may even be so warm that it is even above the average temperature between the temperature at the outlet T2 from the continuous press 2a and the ambient temperature T1.

[0035] The profiled composite strand is transported via a bridging conveyor 8 to a coating device 9. In the exemplary embodiment, one can see, in particular, when considering the Fig. 2 at least one unwinding roll 12a with an upper coating material 18a, and alternatively or jointly at least one unwinding roll 12b for the lower coating material 18b. A replacement or spare roll 15, which can also be used in a flying change if necessary, is merely indicated.

[0036] Films or (resin-impregnated) paper are common and applicable coating materials. In the illustrated embodiment according to the Figure 1 and 2an upper paper web (upper coating material 18a) and a lower paper web (lower coating material 18b) are pulled off the unwinding rolls 12a, 12b, coated with adhesive by an adhesive supply 13 each and finally glued to the upper and lower sides of the composite strand via pressable and, if necessary, heatable pressure rollers 14.

[0037] This is followed by a finishing device for the coating 10, in which, for example, a wider upper coating web 18a is deflected around a rounded edge of the composite strand, for example, and the end is glued to the underside of the composite strand, for example overlapping the lower coating material 18b. Such a design is often seen in simple office desks, where the front edge is created in this way. However, according to the invention, this is done for the first time in a continuous process before cutting into individual panels at the diagonal saw 11.

[0038] Such a (usually circular) saw moves at an angle over the continuous composite strand in order to achieve a cut that is perpendicular to the feed direction.

[0039] Fig. 3shows a typical embodiment of a plasterboard panel in section, with the figure focusing on the design of the edge 20, i.e., the profiling. It also shows how an upper coating paper 18a and a lower coating paper 18b are bonded to the composite strand 16. In the finishing device for coatings 10, the upper coating paper 18a is guided around the milled edge 20 to the underside of the composite strand 16, overlapping the lower coating paper 18b on the underside. The edge 20 itself was previously created in the profiling device 6 using a milling cutter 7, which is suitable for producing the desired curves 17 and bevels.

[0040] However, the profiling must - as Fig. 4shows - not necessarily only at the edge. With a curved V-shaped milling 19 in the composite strand 16, two sections are created, for example with edges that have rounded sections 17. List of reference symbols 1 Plant for producing a material plate 2 Continuous press 2a Exit from the continuous press 3 conveyor track 4 Trimming device 5 Trimming cutting tool 6 Profiling device 7 Partial round milling cutter 8 Bridging conveyor 9 Coating device 10 Finishing facility for coating 11 saw, diagonal saw 12a Roll of upper coating material on unwind station 12b Roll of lower coating material on unwind station 13 Adhesive supply 14 pressure roller 15 Replacement roll of coating material 16 Composite strand 17 Rounding 18a Upper coating material 18b Lower coating material 19 Milling 20 edge T1 Ambient temperature T2 Temperature of the composite strand at outlet 2a

Claims

1. Method of producing composite material boards in which in a continuous press, particles are pressed between two circulating belts, while heat is being supplied, to form a composite material sheet and the composite material sheet exiting from the continuous press (2) subsequently is cut into composite material boards of the desired size and is provided with a profiling process to achieve a non-rectangular composite material board cross-section, characterised in that the profiling process takes place in a profiling machine (6) before the composite material boards have cooled to the mean temperature between the temperature (T2) of the composite material board at the exit (2a) of the continuous press (2) and the ambient temperature (T1).

2. Method according to claim 1, characterised in that the profiling process is carried out in a profiling machine (6) between the exit (2a) of the composite material sheet from the continuous press (2) and a saw (11) for separating the composite material sheet into individual sections.

3. Method according to any one of claims 1 or 2, characterised in that profiling process in a profiling machine (6) includes partial round cutting of the lateral edge of the composite material sheet.

4. Method according to any one of claims 2 or 3 characterised in that between the profiling process in a profiling machine (6) and the separation of the composite material sheet into individual sections by way of the saw (11), at last one-sided coating of the composite material sheet takes place in a coating installation (9).

5. Method according to claim 4, characterised in that between the profiling process in a profiling machine (6) and the separation of the composite material sheet by way of the saw (11), two-sided coating of the composite material sheet takes place.

6. Method according to any one of claims 4 or 5, characterised in that the coating takes place with a paper or film covering, wherein the paper or the film is bonded, more particularly adhered, to one side of the composite material sheet.

7. Installation for the production of composite material boards in accordance with a method according to any one of claims 1 to 6, with a heatable continuous press, a cutting device for producing composite material boards from a composite material sheet of pressed particles exiting from the continuous press and a profiling machine for achieving a non-rectangular composite material board cross-section, wherein the profiling process is carried out by a profiling machine (6) that is arranged at a maximum of 20 m behind the exit point (2a) of the composite material sheet from the continuous press (2).

8. Installation according to claim 7, characterised in that only one conveyor is arranged between the exit point of the composite material sheet from the continuous press and the profiling machine.

9. Installation according to claim 7 or 8, characterised in that the profiling machine (6) is arranged between the exit point (2a) of the composite material sheet from the continuous press (2) and a saw (11) for separating the composite material sheet into individual sections.

10. Installation according to any one of claims 7 to 9, characterised in that the profiling machine comprises a rounding cutter (7).

11. Installation according to any one of claims 9 or 10, characterised in that a coating installation (9) is arranged between the profiling machine and the saw (11).

12. Installation according to claim 11, characterised in that the coating installation (9) comprises a one or two-sided unwinding roller (12a, 12b) for papers or film that are attachable to the composite material sheet (16) as a coating (18a, 18b).