WO2018215405A1

WO2018215405A1 - Device and method for manufacturing a mat and system for manufacturing material boards

Info

Publication number: WO2018215405A1
Application number: PCT/EP2018/063293
Authority: WO
Inventors: Thomas Bucher; Johannes Eckert; Werner Schneider
Original assignee: Dieffenbacher GmbH Maschinen- und Anlagenbau
Priority date: 2017-05-22
Filing date: 2018-05-22
Publication date: 2018-11-29
Also published as: DE102017111178A1

Abstract

The invention relates to a device for manufacturing a mat (1) on a conveyor belt (2), preferably consisting of chips, fibres and/or shreds of biomass, optionally with the addition of binders and/or plastics, during the manufacture of material boards, comprising: at least one scattering apparatus (3) for scattering a mat (1) of a material (14) onto a conveyor belt (2); at least one removal unit (4) for removing material from the mat (1) and levelling the mat (1), wherein the removed material is suctioned off via a suction channel, and a first measuring apparatus (6, 9) for determining at least one first measured value of the mat (1). The invention is characterised in that a second measuring apparatus (6, 9) is arranged for determining at least one second measured value of the mat (1). The invention further relates to a method for manufacturing a mat, and a system for manufacturing material boards.

Description

DEVICE AND METHOD FOR PRODUCING A MAT AND APPARATUS FOR MANUFACTURING MATERIAL PLATES

The invention relates to a device and a method for producing a mat and a plant for the production of material plates.

In the production of material slabs from scatterable materials, a material, usually a mixture of particles or fibrous materials and a binder, scattered to a grit on a forming or conveyor belt, the grit mat is then optionally supplied to a necessary pretreatment and finally a compression , The compression can be carried out continuously or discontinuously by means of pressure and heat. As a rule, these are chip, fiber or OSB boards. Scattering occurs in one or more layers as needed, with the need for multiple layers usually occurring in the production of thicker plates. But also in the production of thin plates, different layers may be desired, especially if specially differentiated requirements should exist between the middle layer and the outer layers.

It has emerged in recent years that several key factors define the cubic meter price of a material board to which the respective producer has little or no influence: these would be energy costs (electricity, oil, gas), material costs (wood and glue) and Plant costs (machines, personnel). In order to survive on the market, a material board manufacturer must minimize the rising energy costs and the rising cost of materials, if possible by making favorable purchases. With glue as well, the material plate producer usually depends on a few glue manufacturers who demand similar prices. Due to the increasing demand for raw materials on the world market in general and for wood in detail, these raw material costs are becoming ever more expensive. The producers are now forced to make the production process more cost-effective while keeping the costs as constant as possible for the customer. Incidentally, the material plate manufacturers are forced with their systems for economic reasons, not only to exhaust the maximum cost savings in plant costs and during operation, but also to offer the most flexible and high-quality production capabilities to fully utilize their manufacturing plant and a 24-hour / 7 To ensure days of operation. All this requires that a large-scale plant nowadays must have a high level of flexibility in order to be able to use its orders in the long term: - processing the widest possible range of raw materials, if possible from the immediate vicinity of the plant (wood, waste ....) , - production of small batches, niche products and special density profiles requested by the customer and, consequently, a fast and easy online conversion of the product range, - ensuring an optimal basis weight distribution over the length and width of the product and - an optimal thickness tolerance to avoid unnecessary finishing in the final production ,

The currently feasible in the industry with respect to an optimal basis weight distribution in mechanical scattering heads and the production of thin MDF boards of a thickness of 3 mm is in the low single-digit percentage range. The production of 8 mm thick floor panels results in a deviation of the basis weight distribution across the panel width of +/- 2.5%. In the standard production of 16 mm thick MDF boards, the result improves to +/- 2.0%. This data is based on 100 mm 100 mm samples, which corresponds to a grid dimension for an economically operable measuring device for the density or the relative basis weight across the width of a pressed material mat. The deviations are therefore in the lower range of points, but it must be noted that with a deviation of 2 to 3.5% there is a fluctuation margin of about 7%, which must be an incentive for every plant operator and hersteller to minimize this fluctuation , There are also significant problems due to the fluctuation range in the daily business, because in a rash up too much material is scattered, that in principle can be pressed without further ado, but with a daily output of nearly 2000 m ³ material plates results in a quasi loss of 60 m ³ compressed material per day in absolute extreme case. Converted to be spread to be crushed The compression results in 420 m ^{3 of} free-flowing material per day, which is uselessly processed. It is not only the material costs per se, but the investment and processing costs of wood chips to strewn chips includes not only the very expensive drying (energy expenditure) but also the use of expensive glue. Incidentally, the buyer of the material plates produced receives material of high density, which may later cause problems in logistics or sales.

From DE 10 2008 027 708 A1 it is already known that for measuring the actual value of the basis weight profile, and thus the relative weight per unit area, a measuring device between the scattering device and the press is arranged that a control device for comparing the actual value of the target value of the basis weight profile and is arranged for determining manipulated variables on at least one adjusting device within the scattering device and that the measuring device and at least one adjusting device are arranged within a distance relative to the length of the pressed material mat of less than 5 m. A further device is known from DE 10 2008 030 417 or DE 10 2013 002 259 A1, in which, after a pre-compaction of the press material mat, an adjustment device for the basis weight is arranged by means of a removal unit and a measuring device for determining the basis weight or the density of the press material mat ,

From DE 10 201 1 016 343 B4 a method for adjusting the basis weight of a scattered on a conveyor bulk material mat is also known, wherein the weight per unit area of the bulk mat in turn is measured by a separate device in front of a removal roller.

It has proved to be disadvantageous in the measuring devices, which use a radiation source and are used to determine the basis weight, that they have a high sensitivity to contamination, for example, soot or heavy metals from combustion, humidity fluctuations of the Starting material or have different starting material. This can lead to unnecessary corrections within the control or control loop, so that more material waste is generated. Based on the relative basis weight, these influences would be found out, since the material is usually formed homogeneously by such influences.

The invention is therefore based on the object to minimize the rejects of material.

It is a further object of the invention to produce a mat having the same characteristics regardless of the variations in the upstream processes.

As a solution, an apparatus for producing a mat on a conveyor belt in the course of the production of material plates is specified, wherein the mat preferably consists of chips, fibers and / or chips of biomass, possibly with admixture of binder and / or plastics, and wherein the Apparatus comprising: at least one spreader for spreading a mat of material onto a conveyor belt; at least one removal unit for removing material from the mat and / or leveling the mat, the removed material being sucked off via a suction channel, and a first measuring device for determining at least one first measured value of the mat. The invention is characterized in that a second measuring device is arranged for determining at least one second measured values of the mat.

Preferably, a measuring device for determining the relative scattering distribution of the mat transverse to the production direction and the further measuring device for determining the absolute basis weight of the mat is arranged. By arranging two measuring devices for measuring measured values of the mat, it is now possible to eliminate fluctuations in the production process and to allow a desired profile or a desired profile of the press mat without any reduction in the absolute basis weight of the mat.

A preferred embodiment is characterized in that the first measuring device is a radiation device, comprising a radiation source and a sensor. The radiation source is preferably an X-ray source or a gamma radiation source. The radiation device is particularly suitable for determining the scatter density or the relative basis weight of the mat transversely to the production direction. In particular, the measurement of the relative basis weight in tracks can be made possible with a transmission device. Relative basis weight indicates how much material in one lane is located relative to the material in another lane and is a measure of weight distribution. For example, in the mat there may be traces of more material at locations to which fasteners will later be introduced.

Alternatively or in combination, the second measuring device is a mechanical basis weight balance. The basis weight scale makes it easy to measure the absolute weight per unit area. The total area weight over the entire width is also an important measurement to check the suitability of the produced plate for certain applications.

Preferably, the first measuring device and then the second measuring device is arranged or vice versa. It is preferred to first determine the relative basis weight and then the absolute basis weight. As a result, the corresponding profile is first set and then the total weight of the mat aligned accordingly. Should the total weight be too low, the desired absolute basis weight can be achieved by uniformly spreading more material or adjusting the height of the removal unit. An alternative embodiment is characterized in that the removal unit comprises at least one removal roller, preferably a plurality of over the width transversely to the production direction extending Abtragwalzen, and more preferably one or more positioning tables, which are arranged below the Abtragwalze under the conveyor belt for lifting the mat. By arranging several removal rollers traces can be generated in the mat or local variations in the scattering of the mat can be removed selectively. Accordingly, the setting tables can be formed with the same width of the removal rollers, so that each removal roller can be assigned to a setting table. By the tables below the conveyor belt, the mat can be raised and thus an improved removal with the table opposite the Abtragwalze be achieved. In addition, the sampling depth can be increased within the mat.

Preferably, the removal rollers and / or the tables are controlled individually and / or the removal roller and / or the tables individually height adjustable executed. As a result, traces can be generated in the mat or local fluctuations can be selectively removed and, in particular, a relative basis weight can be set.

Alternatively or in combination, the distance between the first measuring device and the second measuring device is less than 5 m, preferably less than 3 m, particularly preferably less than 2 m. A short distance between the two measuring devices allows a short control time. But even larger distances less than 15m are still possible for effective control or regulation.

Preferably, the distance of the measuring devices closest to the removal unit to the removal unit is less than 10m, preferably less than 7m, more preferably less than 5m, most preferably less than 3m. Due to the small controlled system between the removal unit and the measuring device, swift fluctuations can be achieved be entered and the profile and the absolute basis weight of the mat adapted to the circumstances.

Preferably, a control unit for controlling or regulating the entry of material into the scattering station and / or the removal unit and / or the removal rollers in dependence on the measured values of the first measuring device and the second measuring device is arranged. The obtained measured values of the first and second measuring device can be compared with a predetermined desired value and be reacted accordingly in case of deviations. Thus, for example, due to the admixture of another type with a slightly different density to the material, an increased absolute basis weight can be measured, so that either more material should be removed by means of the removal unit or less material is supplied to the scattering device.

A further solution of the problem consists in a plant for the production of material plates, comprising a device as stated above and a press, preferably continuously operating press, for pressing the scattered mat to a material plate. In the press, the scattered mat is pressed under pressure and heat to the desired material plate with the desired profile and basis weight.

Preferably, the system further comprises a pre-press, which is arranged between the scattering station and the press. By a pre-press, the mat is vented in a first stage and compressed to a desired value. As a result, the retraction of the mat is improved in the press and, for example, blowouts from the mat can be avoided. In addition, the pre-compaction can improve the removal and leveling, then with a small movement of the removal roller or the setting table more material can be removed. In particular, in the production of fiberboard, the removal unit is arranged after the pre-press. More preferably, the first measuring device and / or the second measuring device are arranged in the production direction before or after the pre-press. In particular, in the production of fiberboard at least one, preferably both measuring devices are arranged after the pre-press, since there the mat has a much lower height. In particular, the removal unit is arranged after the pre-press. In the production of chip and OSB boards, a measuring device in the form of a basis weight scale in front of the pre-press and the further measuring device in the form of a jet unit can be arranged after the press.

Yet another solution to the problem consists in a method for producing a mat, preferably consisting of chips, fibers and / or chips of biomass optionally with the admixture of binder and / or plastics, on a forming belt in the course of the production of material panels comprising the steps: spreading a mat on a conveyor belt by means of at least one scattering station; Leveling with removal of the mat on a predetermined profile by means of a removal unit; Measuring a first parameter of the mat with a first measuring device; and measuring a second parameter of the mat with a second measuring device.

A preferred embodiment is characterized in that the scattering distribution is measured first and then the absolute weight per unit area or vice versa.

Alternatively, the material input into the scattering station and / or the removal unit is controlled or regulated as a function of the measurement of the first measuring device and the second measuring device and a predetermined desired value. The mat can thus be adjusted to the current conditions, such as a change in the composition of the material to achieve after pressing the mat, the desired material plate with appropriate profile and basis weight. Further advantageous measures and embodiments of the subject matter of the invention will become apparent from the following description with the drawings.

The invention is explained in more detail with reference to the drawings. Show it:

Fig. 1 shows schematically a plant according to the invention in a side view and

Top view;

Fig. 2 shows another embodiment of a system according to the invention in one

Side view and a top view;

Fig. 3 shows a further embodiment of a device according to the invention in one

Side view;

4 shows a variant of the embodiment from FIG. 3.

FIG. 1 shows a system according to the invention in a side view in the upper area and a corresponding plan view from above onto the installation in the lower area of the FIGURE. In addition to a press 12 and a pre-press 1 1 for pressing a scattered mat 1, the system comprises a device for generating ebendieser mat first A material 14, which comprises, for example, wood fibers or shavings, is fed to a spreading device 3, which spreads the material 14 to a mat 1, also referred to as fleece, onto a preferably endlessly circulating conveyor belt 2. Adjacent to the scattering device 3, a removal unit 4 for removing too much scattered material 14 from the mat 1 or for producing a desired profile of the mat 1 is arranged transversely to the production direction 13. The removal unit 4 preferably comprises a plurality of removal rollers 5, which are arranged transversely to the production direction 13 next to each other, as shown in dashed lines in the plan view in the lower portion of FIG. The removed material is sucked off by means of a suction channel, which is arranged above the removal rollers 5, and preferably fed back to the scattering process as material 14. To determine the entrance height of the mat 1, a button 16 is arranged in front of the removal roller 4. Due to the height of the button 16, the removal roller 4 is set to a desired height. Each of the removal rollers 4 is separately controllable and adjustable in height, so that this time deeper and sometimes less deeply penetrates into the mat 1 and removes material. To support a plurality of positioning tables 15 may preferably be arranged below the removal roller 4 under the conveyor belt 2, which can lift the mat 1 in the direction of the removal roller 4, so as to further increase the removal. The positioning tables 15 are preferably formed with a width corresponding to the removal rollers 4. The removal rollers 4 can also be offset and arranged in several rows one behind the other in the production direction 13.

In the further course, the mat 1 passes through a first measuring device 6, which in the present embodiment comprises a radiation source 7 and a sensor 8. Such a measuring device 6 can be used in particular for determining the relative basis weight or the profile of the mat 1 transversely to the production direction 13. The radiation source 7, which can be embodied as an X-ray emitter or gamma emitter, illuminates the mat 1, wherein the sensor 8 detects the residual radiation and can create an image of the profile of the mat 1 by means of a control unit 10.

In the further course, a second measuring device 9 is arranged in front of the pre-press 11, which serves to determine a further parameter of the mat 1. In particular, the second measuring device 9 can be designed as a basis weight scale for determining the absolute basis weight of the mat 1. Alternatively, the second measuring device 9 can also be arranged after the pre-press 11. After the mat 1 has now passed at least the measuring devices 6 and 9, this is a press 12, which is formed in the present example as a continuously operating press 12, fed and pressed into material plates such as chipboard, fiberboard or OSB boards.

Both the first measuring device 6 and the second measuring device 9 as well as the removal unit 4 and its components are in operative connection with a control unit 10. By means of the control unit 10, a specific profile and basis weight of the mat 1 and predetermined the entry of material 14 in the scattering unit 3 be adjusted accordingly. By means of the removal unit 4 can now the desired profile in the mat 1 are generated or the mat 1 are leveled. Via the first measuring device 6 with the radiation source 7, an actual value of the profile of the mat 1 can be detected and compared in the control unit 10 with the desired value or the desired profile. If deviations have resulted in the profile, for example, the individual removal rollers 5 or the setting tables 15 can be controlled accordingly and their height changed, so that more or less material is taken from individual tracks of the mat 1 and the corresponding profile is set. In addition to the first measuring device 6, the second measuring device 9 also supplies a further measured value, which is, for example, the absolute basis weight of the mat 1. Again, the measured value of the measuring device 9 can be compared with the target value and be changed at a deviation of the entry of material 14 and / or height of the upper part of the application unit 4 via the height adjustment 17, so that over the entire width of the mat. 1 Seen this more or less material is removed. In addition to the previously discussed measures, of course, the speed of the conveyor belt 2 or the material discharge from the scattering unit can be controlled or regulated accordingly.

FIG. 2 shows an alternative embodiment of FIG. 1, which differs from FIG. 1 in the arrangement of the measuring devices 6, 9. After the removal unit 4, the measurement of the absolute basis weight by means of the measuring device 9 takes place before the mat 1 in the pre-press 11 is precompressed. After the pre-press 1 1 follows the further measuring device 6, which includes a radiation source 7 and the sensor 8, for determining the profile or the relative weight per unit area of the mat 1 transverse to the production direction 13. By pre-compression in the pre-press 1 1 may be again slightly change the profile of the mat 1, since, for example, the edges of elevations in the mat 1 are easily washed out by the pressing. Thus, by the downstream measuring device 6 with the radiation source 7, the profile of the mat 1, better determined and better adjusted by the appropriate control means of the control unit 10. Another embodiment of the device according to the invention is shown in FIG. The material 14 is discharged by means of several scattering devices 3 to a mat 1 on a conveyor belt 2, wherein the scattered material 14 may differ in the individual scattering devices 3. Thus, for example, in the outer scattering devices 3, which may be embodied, for example, as Windtreukammern, fine material scattered to form a cover layer and in the two central scatterers 3 coarser material 14 are scattered to form a middle layer. When producing a mat 1 for OSB boards, the individual scattering devices 3 can be designed for oriented spreading of the material 14 with different orientations.

In contrast to the embodiment of FIGS. 1 and 2, the removal unit 4 is now arranged between two scattering devices 3, here between the two middle scattering devices 3. This has the advantage that the mat 1 is modeled or leveled only in a specific layer. The outer layers of the mat 1 are thereby not destroyed, so that the mat 1 can be coated, painted or laminated without any problems after being pressed. After the last scattering station 3, a first measuring device 6 with a radiation source 7 and a second measuring device 9, again embodied as a basis weight scale, is arranged again. The two measuring devices 6 and 9 allow the determination of the relative basis weight or the distribution transverse to the production direction 13 and the absolute weight per unit area of the mat 1 before it is fed to a press 12 (not shown). From the measurements of the two measuring devices 6, 9, a comparison with the set profile and basis weight in a control unit 10 and accordingly the height adjustment 17 of the removal unit 4 are changed to change the absolute basis weight or the height adjustment 18 of the individual discharge rollers 5 to change the relative Basis weight in one or more tracks in the mat 1 are operated. In addition to the height adjustment 17, 18 and the entry of material 14 in the scatterers 3 or only a part of the scatterers 3 are changed when, for example, a material accumulation before the removal unit 4 results or the individual discharge rollers 5 due to a low mat height no longer can set the appropriate profile. An alternative embodiment of Figure 3 is shown in Figure 4, wherein the removal unit 4 is arranged in front of the last scattering devices 3. Thus, it is always possible to achieve a fine surface of the mat 1 necessary for coating or painting. The desired profile or the leveling of the mat 1 can now take place before the last scattering devices 3 and thus can usually be set more precisely, since corresponding errors in the scattering devices 3 arranged in front of the removal unit 4 can be eliminated by means of the removal unit 4.

The invention has been fully described and explained with reference to the drawings and the description. The description and explanation are to be considered as illustrative and not restrictive. The invention is not limited to the disclosed embodiments. Other embodiments or variations will become apparent to those skilled in the art upon use of the present invention and upon a thorough analysis of the drawings, the disclosure, and the following claims.

In the claims, the words "comprise" and "with" do not exclude the presence of further elements or steps. The undefined article "a" or "an" does not exclude the presence of a plurality. A single element or unit may perform the functions of several of the units recited in the claims. The mere mention of some measures in several different dependent claims is not to be understood that a combination of these measures can not be used equally advantageous. Reference signs in the claims are not intended to be limiting. List of Reference P1571

1 mat

2 conveyor belt

3 spreading device

4 removal unit

5 removal roller

6 measuring device

7 radiation source

8 sensor

9 measuring device

10 control unit

1 1 pre-press

12 press

13 production direction

14 material

15 table

16 buttons

17 height adjustment

18 height adjustment

Claims

claims

1 . Device for producing a mat (1) on a conveyor belt (2),

preferably consisting of chips, fibers and / or chips of biomass optionally with admixture of binder and / or plastics, in the course of the production of material plates, comprising:

At least one spreading device (3) for spreading a mat (1) of a material (14) onto a conveyor belt (2);

at least one removal unit (4) for removing material from the mat (1) and / or leveling the mat (1), wherein the removed material is sucked off via a suction channel, and

a first measuring device (6, 9) for determining at least one first

Measurement of the mat (1), characterized in that a second

Measuring device (6, 9) for determining at least a second measured values of the mat (1) is arranged.

2. Apparatus according to claim 1, characterized in that a

Measuring device (6, 9), the relative scattering distribution of the mat (1) across the

Production direction (13) and a further measuring device (6, 9) the absolute basis weights of the mat (1) is determined.

3. Device according to one of the preceding claims, characterized

in that the first measuring device (6, 9) has a

Radiating device is, comprising a radiation source (7), preferably an X-ray source, and a sensor (8).

4. Device according to one of the preceding claims, characterized

in that the second measuring device (6, 9) is a mechanical basis weight balance.

5. Device according to one of the preceding claims, characterized

characterized in that first the first measuring device (6, 9) and then the second measuring device (6, 9) is arranged or vice versa.

6. Device according to one of the preceding claims, characterized in that the removal unit (4) at least one removal roller (5), preferably a plurality across the width transversely to the production direction (13) arranged Abtragwalzen (5), and more preferably one or more tables ( 15), which are arranged below the removal roller (5) under the conveyor belt (2) for lifting the mat (1) comprises.

7. Device according to one of the preceding claims, characterized

in that the removal rollers (5) and / or the positioning tables (15) are preferably individually controllable, and / or the removal roller (5) and / or the adjustment tables (15) are individually height-adjustable.

8. Device according to one of the preceding claims, characterized

in that the distance between the first measuring device (6, 9) and the second measuring device (6, 9) is less than 5 m, preferably less than 3 m, particularly preferably less than 2 m.

9. Device according to one of the preceding claims, characterized

in that a control unit (10) for controlling or regulating the entry of material (14) into the spreading station (3) and / or the removal unit (4) and / or the removal rollers (5) in dependence on the measured values of the first measuring device ( 6, 9) and the second measuring device (6, 9) is arranged.

10. Plant for the production of material plates, comprising a device according to one of claims 1 to 9; and

a press (12), preferably continuous press (12), for pressing the scattered mat (1) to a material plate.

1 1. Plant according to claim 10, further comprising a pre-press (11), which

between the scattering station (3) and the press (12) is arranged.

12. Plant according to one of Ansprüchel O to 1 1, characterized in that the first measuring device (6, 9) and / or the second measuring device (6, 9) in

Production direction (13) before or after the pre-press (1 1) is arranged.

13. A method for producing a mat (1), preferably consisting of chips, fibers and / or chips of biomass optionally with the admixture of binder and / or plastics, on a forming belt in the course of the production of

Material plates, comprising the steps:

Spreading a mat (1) or a fleece on a conveyor belt (2) by means of at least one scattering station (3);

Leveling with removal of the mat (1) to a predetermined profile by means of a removal unit (4);

Measuring a first parameter of the mat (1) with a first measuring device (6, 9); and

Measuring a second parameter of the mat (1) with a second measuring device (6, 9).

14. The method according to claim 13, characterized in that the scattering distribution is measured first and then the absolute basis weight or vice versa.

15. The method according to any one of claims 13 to 14, characterized in that the material input into the scattering station and / or the removal roller is controlled or regulated in dependence on the measurement of the measuring device and / or the basis weight scale.