Device and method for separating pressed material mats

Abstract

Device for separating a press material mat (2) formed from chips, fibers or shreds on a transport device (4) in front of a press (3) for producing material sheets with at least one brush (9) that can be lowered from a ready position (20b) and rotated and a suction device (11), characterized in that the brush (9) is located at least partially in a suction bell (11) belonging to the suction device (10), which can also be lowered from a ready position (20g) to a working position (21g), wherein the movements of the brush (9) and the suction bell (11) can be controlled independently of each other.

Description

[0001] The invention relates to a device for separating a pressed material mat formed from chips, fibers or shreds on a transport device in front of a press for the production of material sheets, with at least one brush that can be lowered from a ready position and driven by a rotary mechanism and a suction device.

[0002] The invention further relates to a method for separating pressed mats using such a device.

[0003] Examples of the aforementioned material panels include chipboard, OSB panels, lightweight panels, multi-layer panels, HDF or MDF panels.

[0004] The spreadable material (essentially glued wood shavings in connection with this invention) scattered onto the transport device will hereinafter be referred to as a pressed material mat. These pressed material mats can have thicknesses ranging from a few millimeters to one meter. Modern spreading stations are capable of varying the amount of material spread both in the conveying direction of the transport device, which is usually designed as a conveyor belt, and in the transverse direction, using one or more serially connected, metering-adjustable spreading stations. Several serially connected spreading stations allow for the formation of different layers, such as top and middle layers.

[0005] The conveying system, usually one or more conveyor belts, transports the pressed material mat to a press. In the invention, this press, typically a double-belt press, applies pressure and heat to the pressed material mat, which is fed in a conveying direction via the conveyor belt. Devices designed in this way are frequently used for two purposes. Firstly, they produce solid products from pressed chips or fibers. The invention focuses on the production of particleboard or fiberboard. The pressed material mat is thus compacted and pressed by the pressure.

[0006] On the other hand, the addition of heat allows moisture to evaporate and binders to harden.

[0007] The choice of material for the bristles or brush head of the brush can vary considerably depending on the material being pressed. While some empirical data exists, the most suitable material for a specific application can be quickly determined through trials. Natural fibers, synthetic fibers, or wire are all possibilities. In this description, "bristles" refers to any form of brush head, including, for example, elastic lamellae. Preferably, the bristles are mounted around the circumference of a roller, which extends at least across the width of the pressing mat.

[0008] It is essential to prevent unwanted foreign materials from entering the press. Therefore, the pressing mat is detected for foreign objects, and if necessary, a section of the mat is cut off and disposed of at a recycling station.

[0009] Patent literature contains numerous publications dealing with the topic of removing foreign materials from pressed material mats or fiber mats. Examples include EP 1 782 933 B1 and DE 10 2006 049 087 B4. After the removal of unwanted components or after restarting the system, the material mat is typically cut straight across to ensure the continuous press's (steel) belts are loaded as evenly as possible. This creates entry edges facing the press, running vertically across the entire height of the material mat.

[0010] With conventional methods, the negative experience has been that a large part of the chips and fibers are stirred up during the cutting process, causing contamination of machines, halls and the surrounding air.

[0011] It has also been shown that feeding the mat into a continuous double-belt press with a vertical edge can be detrimental. At the moment of entry, the mat delivers an impulse or impact to the lower and / or upper belt of the continuous press. This impact is transmitted across the entire width of the mat to the rollers supporting the belts and the chain links guiding them. With the wide and high mats commonly used today, this impact is so significant that it leads to accelerated wear.

[0012] The invention therefore aims to create a separating device and a separating process in which a press inlet-friendly mat edge is produced while avoiding dust generation.

[0013] The problem is solved with regard to the device with the features of claim 1 and in particular by the fact that the brush is located at least partially in a suction bell belonging to the suction device, which can also be lowered from a standby position to a working position, wherein the movements of the brush and suction bell can be controlled independently of each other.

[0014] The suction bell can thus adapt to the current position of the brush, or vice versa. This means that as soon as the brush begins to remove chips, fibers, or shreds from the mat, the suction bell can be moved into the correct "suction position." Alternatively, the suction bell can be moved into a working position immediately before the brush enters the pressing mat. The extracted material at the separation point can then be conveyed, for example, via pipelines for recycling. A control unit allows the lifting and lowering movements of the brush and suction bell to be controlled independently. This enables coordination between the two units, resulting in a separation process that is as dust-free as possible.

[0015] As the brush enters the compaction mat, it creates a convex edge. This means that, in longitudinal section, the mat has a pointed leading edge at the bottom, which gradually recedes towards the top. When a double-belt press is used for compaction, the mat enters with a flat layer that gradually increases in height. This moderately increases the pressure on the surrounding pressure belts and prevents excessive pressure pulses.

[0016] It is advantageous if the lowering process of the brush and suction bell begins with the suction bell.

[0017] This offers the advantage of allowing the suction bell to be moved very close to the surface of the pressing mat before the rotating brush makes contact with it. This prevents any turbulence into the surrounding area.

[0018] Preferably, the suction bell can be lowered to a few millimeters above the surface of the pressing mat.

[0019] This prevents the suction bell from coming into contact with the pressing mat. On the other hand, the remaining gap is large enough to allow a necessary amount of suction air to be drawn into the extraction device, which can carry the chips, fibers, or shreds stirred up inside the suction bell into the extraction device's discharge pipes.

[0020] Advantageously, the suction device includes an ejector that has an evacuation time of less than 2 seconds to generate the required vacuum in the suction bell.

[0021] This ensures that the shavings, fibers, or chips removed by the brush can be vacuumed up immediately. It also prevents shavings, fibers, or chips that never came into contact with the brush from being lifted from the surface of the mat due to a slow build-up of negative pressure.

[0022] It is preferable to have a free space above the brush in the suction bell.

[0023] This clearance not only allows the extracted chips, fibers, or shavings unimpeded access to the extraction device. The extraction device is preferably implemented by several suction tubes arranged across the width of the press mat on the suction bell, which are connected elsewhere to a central suction line or a fan. The clearance also allows the suction bell to begin its downward movement towards the press mat unimpeded by the brush.

[0024] Preferably, the brush has the shape of a hyperboloid with a horizontal axis of rotation.

[0025] The immersion of the brush in the pressing mat simultaneously creates a curved edge. This further reduces the stress on the circulating press belts of the subsequent continuous press.

[0026] It is advantageous if the device is located near a disposal station.

[0027] From DE 10 2006 049 087 84 it is known how the transport devices create an opening immediately after a separation point in the pressed material mat in order to tip the mat rejects into the disposal device. The separation points in the mat, which define the mat section to be rejected, are achieved by two inserts of the device according to the invention.

[0028] Preferably, the bristles of the brush are arranged offset on the circumference and / or in an axial direction on the surface of a roller.

[0029] This allows for larger gaps between individual bristles, thus simplifying brush manufacturing and increasing its strength. In principle, this is achieved, for example, by creating several combs arranged radially and axially around the circumference of the brush roller, with their elastic tines offset from each other in the circumferential direction. It is also advantageous that a scraper or other cleaning element for the brush can be arranged within the suction cup.

[0030] Preferably, the brush drive is suitable for changing the direction of rotation.

[0031] If the brush's rotation direction is reversible, this allows for influencing the edges of the pressed material mat. For example, the beginning of a pressed material mat can be produced differently than the end of a rejected piece. The direction of the "chip flight" can also be particularly advantageously influenced by reversing the direction of rotation.

[0032] The problem is solved with regard to the method for separating pressed material mats with the aforementioned device according to one of claims 1 to 9 with the features of claim 10 and in particular by the fact that for separating the pressed material mat - the suction bell is lowered until it is close to the surface of the pressing mat, - a vacuum generation is activated and - which dips into the pressing mat and stirs up the chips or fibers or shreds within the suction bell so that they are sucked up, - and then lift the brush back from the pressing mat.

[0033] The claim to the method clarifies that the brush's insertion into and removal from the compaction mat should occur very quickly to avoid having to suction up too much material. Preferably, the brush's insertion and removal from the compaction mat takes place in less than one second, and even more preferably in less than 0.5 seconds. At a compaction mat speed of 1 m / sec, the suctioned distance is then less than 50 cm. Such a wide separation area (especially compared to a saw cut) simplifies the control of the transport device when opening and closing the gap to a disposal station.

[0034] Preferably, a first separation of the pressed material mats with the brush takes place shortly before or after opening a gap in the transport device towards a disposal device, and a second separation takes place shortly before closing the gap.

[0035] This process makes it possible to discard the section of compressed material mat to be removed and then to convey the new section of mat to the press via the transport device. The relative term "short" here depends on the distance between the separating device and the disposal station. Assuming that the mat moves along its transport device at a speed of at least 1 meter per second, a period of less than five seconds is considered "short".

[0036] Alternatively, it is preferred that two brushes positioned one behind the other in the direction of conveyance separate out a portion of the pressed material mat to be disposed of.

[0037] There are therefore two brushes, one of which creates the beginning of the section of the compacted material mat to be disposed of, and the other the end. This section of mat falls into the disposal station, which is opened at the appropriate time and must be closed again precisely before the next section of compacted material mat reaches the end, so that it can be conveyed on the transport device.

[0038] The invention is explained in more detail below with reference to the drawings.

[0039] This shows Fig. 1 a schematic side view of the device for separating and an indicated inlet into a continuous press, Fig. 2 to Fig. 10 the step-by-step process of removing a section of pressed material mat to be separated using the device according to the invention for separating, Fig. 11 a brush with a roller with staggered bristles, and Fig. 12 a special type of brush

[0040] In the Fig. Figure 1 illustrates the feeding of a press mat 2 to a continuous press 3 during the production of material panels, e.g., MDF panels. This system, in its basic configuration, includes a transport device 4, which in this embodiment is designed as a belt conveyor with an endless circulating conveyor belt. A press mat 2 is applied to this transport device 4, e.g., by continuous spreading. Within the scope of the invention, the term "press mat" therefore refers specifically to an "endless" strand of mat material, which is pressed into a sheet strand in a continuous press 3. Such a pressed sheet strand is then typically cut into individual panels downstream of the continuous press 3. Furthermore, the system includes an intermediate conveyor 16, which is arranged between the transport device 4 and the continuous press 3, which is only indicated.The intermediate conveyor 16 can also be designed as a belt conveyor. This intermediate conveyor 16 typically extends into the inlet opening of the continuous (double belt) press 3, thus feeding the press mat 2 into the press 3. For the purpose of diverting excess material into a disposal device 8, the transport device 4 has a transfer nose 17 that is movable along the conveying direction F and is connected to the intermediate conveyor 16 in a transfer position. This transfer position is shown in . Fig. 1 shown.

[0041] From this transfer position, the transfer nose 17 can be moved into a discharge position that releases a disposal device 8, so that mat parts that are, for example, contaminated, can be disposed of. This arrangement and this process are known from DE 10 2006 049 087 B4 and are described in the invention in the Fig. Points 2 to 10 will be explained again.

[0042] In the area of ​​the transport device 4, or above the transport device 4, a device for separating the pressed material mat 5 transversely to the conveying direction F is provided. In the exemplary embodiment according to all figures, this device for separating the pressed material mat 5 comprises a rotatably driven brush 9 and a suction device 10 with a suction bell 11 at least partially surrounding the brush 9, one or more suction pipes 22, and a vacuum generator, here in the form of an ejector 13.

[0043] With the aid of actuators not shown, such as pneumatic differential cylinders, both the suction bell 11 and the brush 9 can be adjusted independently in height by the actuators, for example, acting on the ends of the components and being controlled by a control unit also not shown.

[0044] There is therefore a ready position for both the brush 9 and the suction bell 11 above the pressing mat 2. These two positions are designated by reference numerals 20b for the brush and 20g for the suction bell. Furthermore, there is a working position for the brush 9 and the suction bell, designated 21b and 21g in the following figures. In this position, the suction bell is positioned close to, that is, a maximum of 5 to 10 mm above, the surface of the pressing mat 2, and the brush 9 is immersed in the pressing mat 2.

[0045] In this embodiment, the brush 9 has a roller body 7 extending across the width of the pressing mat 2, which is provided with bristles 6. The material of the bristles 6 depends on the material of the pressing mat 2 and can be made of natural fibers, synthetic fibers, or wire. Lamellas can also be provided instead of bristles. The roller body is driven rotaryally by a motor (not shown).

[0046] With the Fig. In sections 2 to 10, the process of separating and disposing of the press mat part 19 to be disposed of is shown step by step in its chronological sequence.

[0047] Fig. Figure 2 shows the separating device 5 and the suction device 10 in the described ready position of suction bell 11 and brush 9 above the pressing mat 2. The gap 14 between transport device 4 and intermediate conveyor 16 is still closed.

[0048] In the Fig. Figure 3 shows how the first separation takes place in the pressing mat 2. The suction bell is in its working position 21g close above the pressing mat 2 and the brush 9 is already immersed in the pressing mat in its working position 21b.

[0049] Fig. Figure 4 shows in the continuous sequence how the brush 9 and, in this example, also the suction bell 11 have returned to their ready positions 20b and 20g. The separation point 18 of the compressed material mat created by the brush 9 moves towards the gap 14.

[0050] Fig. Figure 5 shows how the gap 14 opens upon reaching the press mat separation point 18. For this to happen, the transfer nose 17 moves back against the conveying direction F. The inlet edge 15 tilts into the disposal station 8.

[0051] According to Fig. 6. The separating device, as before, now creates a second separation point. Thus, the length of the compacted material mat section 19 to be disposed of is defined by the two separation processes. A foreign object, for example, was previously detected in this section of the compacted material mat. Alternatively, it would also be possible to provide two separation devices, one of which creates the beginning and the other the end of a compacted material mat section to be disposed of.

[0052] In Fig. Figure 7 shows the second separation point 18 of the compressed material mat, which limits the end of the compressed material mat part 19 to be disposed of, according to Fig. 8 is also moved to the gap 14. The brush 9 and the suction bell 11 have returned to their ready position.

[0053] In Fig. Figure 9 shows how the gap 14 is closed the moment the new inlet edge 15 of the pressing mat 2 reaches it. This makes it possible to see, as can be seen in Fig. 10 recognizes that the inlet edge 15 has now passed onto the intermediate conveyor 16.

[0054] The new inlet edge 15, which is conveyed to the continuous press 3, has a noticeably concave shape. This prevents the press belts 23 of the continuous press 3 from being subjected to sudden impact loads. Instead, the pressure on the pressing mat 2 builds up gradually, which increases the service life of the press belts 23.

[0055] Fig. Figure 11 indicates that the brush 9 can consist of a roller 7 whose bristles 6 are not arranged symmetrically. For example, they are arranged offset around the circumference of the roller 7. This reduces the number of bristles 6 required. In this example, when the roller 7 rotates, the bristles at the top and those at the bottom would comb the chips, fibers, or shreds from the pressing mat 2, which would then be extracted by a suction bell.

[0056] Fig.Figure 12 shows a special design of the brush 9. It has a hyperboloid shape. When the brush 9 enters the pressing mat 2, the inlet edge 15 is curved across the width of the pressing mat in addition to its concave shape. This means that after the portion of the pressing mat located between the new inlet edge 15 (created by the brush lowering) and the press has been removed by the disposal devices 8 before entering the continuous press, the new inlet edge 15 does not have to bear the entire width of the pressing mat between the press belts 23. Instead, the pressure on the press belt spreads slowly and gently across the width of the pressing mat 2. Reference symbol: 1 Plant for the production of material panels 2 Pressed material mat 3 Continuous Press 4 Transport equipment 5 Device for separating the pressed material mat 6 bristles 7 roller 8 disposal stations 9 brush 10 Extraction device 11. Suction cup 12 Free space 13 Ejector, vacuum generator 14 columns 15 Inlet edge 16 intermediate conveyors 17 Transfer nose 18 Pressed material mat separation point 19. Pressed material mat section to be disposed of 20b Ready position brush 20g standby position suction cup 21b Working position brush 21g working position suction cup 22 Suction pipe 23 Press band of the press 24 Deflection roller for press belt F Conveyor direction

Claims

[1] Device for separating a press material mat (2) formed from chips, fibers or shreds on a transport device (4) in front of a press (3) for producing material sheets, comprising at least one brush (9) that can be lowered from a ready position (20b) and rotated, and a suction device (11), characterized by that the brush (9) is at least partially located in a suction bell (11) belonging to the suction device (10), which can also be lowered from a standby position (20g) to a working position (21g), wherein the movements of the brush (9) and the suction bell (11) can be controlled independently of each other. [2] Device according to claim 1, characterized by , that the lowering process of brush (9) and suction bell (11) begins with the suction bell (11). [3] Device according to claim 1 or 2, characterized by , that the suction bell (11) can be lowered to within a few millimeters above the surface of the pressing mat. [4] Device according to any one of claims 1 to 3, characterized by , that the suction device (19) includes an ejector (13) which has an evacuation time of less than 2 seconds to generate the required vacuum in the suction bell (11). [5] Device according to any one of claims 1 to 4, characterized by , that a free space (12) is present above the brush (9) in the suction bell (11). [6] Device according to any one of claims 1 to 5, characterized by , that the brush (9) has the shape of a hyperboloid with a horizontal axis of rotation. [7] Device according to any one of claims 1 to 6, characterized by , that the device is located near a disposal station (8). [8] Device according to any one of claims 1 to 7, characterized by , that the bristles (6) of the brush (9) are arranged offset on the circumference and / or in an axial direction on the surface of a roller (7). [9] Device according to any one of claims 1 to 8, characterized by , that the drive of the brush (9) is suitable to change the direction of rotation. [10] Method for separating a pressed material mat (2) according to any one of claims 1 to 9, characterized by , that to separate the pressed material mat (2) - the suction bell (11) is lowered until it is close to the surface of the pressing mat (2), - a vacuum generator (13) is activated to generate a vacuum inside the suction bell (11) and - the brush (9) is immersed in the pressing mat and the chips or fibers or shreds are stirred up inside the suction bell (11) so that they are sucked up, - and then lifts the brush (9) away from the pressing mat (2). [11] Method according to claim 10, characterized by that the brush enters and re-emerges from the mat in a period of less than one second. [12] Method according to claim 10 or 11, characterized by, that a first separation of the press material mats with the brush (9) takes place shortly before or after the opening of a gap (14) in the transport device (4) towards a disposal device (8) and a second one takes place shortly before the closing of the gap (14). [13] Method according to any one of claims 10 to 12, characterized by , that two brushes (9) arranged one behind the other in the direction of conveyance (F) separate out a portion of the pressed material mat (19) to be disposed of.

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