EP3572197A1 - Device and method for dispersing a fleece on a forming web - Google Patents

Abstract

The present invention relates to a device for scattering a nonwoven fabric (11) on a continuous forming belt (12) underneath the device (10), in particular in the course of producing material plates of free-flowing material (1) such as fibers or chips, wherein the device ( 10) comprises: - an upper inlet opening for feeding the material (1) and a lower outlet opening for dispensing the material (1) onto the forming belt (12), - at least one distribution roller (14) and a spreading roller (15) transversely to the transport direction ( 13) of the forming belt (12) and a discharge device (2) for removing portions of material (1), wherein on the discharge device (2) transversely to the transport direction (13) a plurality of adjustable in size openings (3) are arranged to the Deposition of material (1) from the device (10) with a conveying device (21) for the through the openings (3) passing material (1) are operatively connected. The invention consists in particular in that in the discharge device (2) a cover plate (4) and a plurality of slides (5) are arranged with an opening (6), wherein for adjusting the size of the opening (3) the cover plate (4) the aperture (6) partially covers and the cover plate and / or the slide (5) by means of at least one actuator (17) are arranged displaceably.

Description

The present invention relates to a device for scattering a nonwoven on a forming belt, in particular in the course of the production of material plates, according to the preamble of claim 1. Furthermore, the invention relates to a method for scattering a nonwoven on a forming belt according to the preamble of claim.

In the production of material plates from spreadable material, a mixture of particles or fibrous materials and a binder is scattered to a nonwoven on a forming or conveyor belt. This grit mat is then fed to a possibly required pretreatment of a continuous or discontinuous pressing, which can be done by means of pressure and / or heat. For example, in this type of material plates such as MDF (medium-density fiberboard) or OSB (Oriented Strand Board or chipboard) can be produced. The compression takes place mostly in a continuous belt press, in which a spreading material mat by means of a circulating flexible belt, in particular a steel strip, the compression is supplied. Typically, a plurality of press cylinders apply a pressing pressure across the belt to the grit mat while the grit mat is heated by hot plates. Between the belt and the press cylinders rolling rods are usually arranged to reduce friction and pressure transfer.

One of the fundamental challenges of this technology for decades has been the optimal production of nonwovens, also called pressed goods or spreading material mats, on said forming belt. It is important to ensure that given surface weights in width and length are optimally adhered to by a To avoid over- or under-scattering. Overscattering results in unnecessary loss of material for the producer; undercutting does not reach the standard values of the product. Due to current raw material developments and legal requirements, plate producers are now required to use as little material as possible while retaining the same characteristics. In addition to a very accurate and uniform scattering, there is the possibility to adjust given density profiles longitudinally and transversely in the continuously moving nonwoven fabric in order to be able to produce, for example, a lightweight material plate with predetermined high-density edges or particularly suitable regions of higher density for fittings.

Suitable methods and apparatus for producing such nonwovens are with EP 0 069 162 B1 . EP 0 230 483 B1 and EP 0 292 581 B1 known. All these disclosures are the same that a device is arranged between a metering device and a nonwoven receiving the web, in which the material flow emerging from the metering device is distributed and stored by means of suitable machine elements on the forming belt to form a nonwoven. Furthermore, discharge devices are disclosed in these devices, which selectively divert material from the flow of material during the production of the nonwoven and with an adjustable profile across the width of the endlessly circulating forming belt in order to achieve the predetermined density properties of the nonwoven. In some cases, these discharge devices also have options for metering the discharged material to the fleece, preferably at another location or evened out.

It has now been found that the devices and the proposed methods are no longer able to meet the requirements of the manufacturing industry for material plates.

The present invention has for its object to improve the adjustability of the device for producing a nonwoven over the prior art. In an extension of this task, it should be avoided, in particular, that the material to be extracted accumulates in front of the openings of the discharge devices or obstructs one another and in particular makes it difficult to regulate.

The invention is based on a device for scattering a nonwoven on a continuously circulating below the device forming belt, especially in the course of the production of material plates of free-flowing material such as fibers or chips, the device having an upper inlet opening for the task of the material and a lower outlet opening for Dispensing of the material on the forming belt, at least one distribution roller and a scattering roller transversely to the transport direction of the forming belt and a discharge device for removing portions of material comprises, wherein on the discharge device transversely to the transport direction a plurality of adjustable in size openings are arranged, for the deposition of material the device is operatively connected to a conveying device for the material passing through the openings.

The solution of the task for the above-mentioned device is that in the discharge a cover plate and adjacent a plurality of sliders are arranged with an opening, wherein for adjusting the size of the opening, the cover plate partially covers the breakthrough and the cover plate and / or Slider are arranged displaceably by means of at least one actuator.

This solution is based in particular on the finding that it is advantageous if the adjustable openings increase in the fall direction of the material, ie preferably has an upper fixed boundary and an expanding opening opens downward in the direction of the forming belt. Conversely, to reduce the size of the opening, the lower boundary (forming belt side) will move upwards away from the forming belt. Particularly preferably, an opening will be arranged in the device such that a material stream which impinges on the discharge device or the openings makes an opening with its upper region and the lower region of the material stream is diverted downwards in the direction of the forming belt.

In an advantageous embodiment, the lower end of the cover plate is arranged as the upper boundary of the opening and the opening of a slider as the lower boundary of the opening in the direction of fall of the material. This is in Entry direction of the material in the discharge device, the cover plate in front of the slide.

In a further advantageous embodiment, in a fixed cover plate for adjusting the opening of the slide with its breakthrough substantially against the material flow direction in the device (ie from top to bottom in the direction of the forming belt) arranged to reduce the opening and in the material flow direction to increase the opening movable ,

Alternatively or cumulatively, at least one nozzle for pneumatic cleaning of parts of the discharge device, in particular of the openings, can be arranged in the discharge device.

As an alternative to a cover plate, the cover plate may also have an opening and preferably be arranged in a size that substantially covers the range of movement of the slider. Thus, the slide is substantially covered and caking between the slide and cover plate can be scraped by moving each other.

Alternatively, another cover plate may be arranged opposite the first cover plate relative to the openings, wherein preferably the further cover plate releases the region of the adjustable openings but covers the wider area of the slides. Again, a cleaning effect can be realized, at the same time over the width of the forming belt and starting from the discharge a predetermined lower fall edge is provided on which the material which remains in the device and is guided in the direction of the forming belt. This results, as in the past compared to the prior art, no irregular discharge edges at the lower end of the discharge device on the form side.

Preferably, for adjusting the position or the position of the openings in the device, the discharge device can be movable. In particular, it may also be arranged vertically adjustable with respect to the forming belt. This serves for improved regulation as a function of the type and / or density of the material or of the material mixture. Meanwhile, reinforced material mixtures are used with a high proportion of recycled wood, which another throw and Distribution characteristic may have in the device. Changes in the particle size distribution may also make it necessary to arrange the discharge device at a different position or to change the angularity of the discharge device relative to the distribution rollers.

A preferred control or regulating device will provide a measuring device for the basis weight or the density distribution of the web at a predetermined distance from the device and change the device respectively the position of the discharge device and / or the slide / cover plates to each other via the measurement result or a Regelalgorhythmus interpret the measurement result to reach the specified setpoint.

A generic method for scattering a nonwoven on a below a device for scattering material endlessly circulating mold belt, especially in the course of the production of material plates of free-flowing material such as fibers or chips, consists essentially in that through an upper inlet material into the device and The material is guided onto the forming belt via a lower outlet opening and the material is essentially distributed by a distributing roller in the device and is applied to the forming belt by means of at least one scattering roller and taken in sections by a discharge device in the device transversely to the transport direction of the endless forming belt is made by several adjustable in size openings feed the material passing through a conveyor for removal from the device.

The invention for the method is that the adjustable openings of the discharge device are formed by a cover plate and a plurality of slides with openings, wherein the opening of a slide to reduce the opening is partially covered by the cover plate by means of at least one actuator, the cover plate and / or the slides are moved to each other.

In this case, the lower end of the cover plate is preferred as the upper boundary of the opening and the breakthrough of a slider than the lower in the direction of the material Limitation of the opening used.

To adjust the opening, the slide with its opening is particularly preferably displaced substantially counter to the material flow direction for reducing the opening and in the material flow direction for enlarging the opening.

In order to avoid clogging, at least one nozzle for the pneumatic cleaning of parts of the discharge device, in particular the openings, can be used in the discharge device.

Alternatively, the cover plate may also have an opening and preferably be used in a size which allows to substantially cover the range of movement of the slider.

On the other hand, another cover plate may lie opposite the first cover plate relative to the openings, wherein the further cover plate releases the region of the adjustable openings but covers the lower area of the slides.

Alternatively or cumulatively, for adjusting the position or the position of the openings in the device, the discharge device can be arranged to be movable, in particular height-adjustable with respect to the forming belt.

It is particularly preferred that the stream of material striking the discharge device is guided onto the openings in such a way that the upper part of the stream facing away from the forming belt is guided into the opening and the lower region of the stream is deflected depending on the size of the opening, for example stopped by the slider and guided down towards the forming belt.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Fig. 1

einen Längsschnitt durch die Vorrichtung gemäß der Erfindung entlang der Transportrichtung des Formbandes und

Fig. 2

eine vergrößerte Darstellung der Austragsvorrichtung.

The invention will be described in more detail below with reference to some selected embodiments in conjunction with the accompanying drawings and explained. Show it:

Fig. 1

a longitudinal section through the device according to the invention along the transport direction of the forming belt and

Fig. 2

an enlarged view of the discharge.

In FIG. 1 In a longitudinal section through the device 10 along the transport direction 13 of the endlessly circulating forming belt 12, the material flow of the material 1 through the device and the production of the fleece 11 on the forming belt 12 are shown schematically. The material 1 passes in the direction of fall 9 through an upper opening in the device 10, is therein by at least one distribution roller 14 in the device and distributed and passes on optional rake 7 finally on at least one scattering roller 15, which the material 1 on the forming belt 12 stores. The optional rakes 7 serve to divert a portion of the material and pass a portion in the throw or fall direction to allow for a predetermined distribution within the device.

In the device 10, at least one discharge device 2 is arranged, which in an exemplary position in the device 10 in FIG FIG. 1 is shown and in FIG. 2 is explained in detail by an enlarged view. In the device 10 14 different material flows are formed by the direction of fall and / or the distribution rollers 14, which can be. If necessary, also be controlled by the optional rake 7 accordingly. If a part of the material 1 now strikes the discharge device 2 as material flow, the material flow is diverted downwards in the direction of the forming belt 12 or the scattering rollers 15 and another part is conveyed through the openings 3, if they are open, in the discharge device 2 a conveyor 21 which removes the material 1 from the device 10. As a conveying device 21 can along an axis 16 transverse to the forming belt 12, a screw conveyor (not shown) in a material 1-catching screw trough 19 may be arranged, which transports the material 1 in the screw trough.

According to one embodiment, the opening 3 is formed by an opening 6 in a slide 5 and covered to adjust the size of the opening 3 by means of a cover plate 4. If an opening 3, which are across the width of the device 10, respectively transversely to the transport direction 13 of the forming belt 12, arranged in a variety are changed in size, the corresponding slide 5 with its opening 6 and / or the corresponding to This cover associated cover 4 are moved. The more the cover plate 4 covers the opening 6 of the slider 5, the smaller the opening 3 will be.

It has surprisingly been found by experiments that the adjustability of the device 10 can be significantly improved if the opening 3 is formed from two different sliding plates, which together form an adjustable opening 3.

In operation, the adjustability is then ensured outstanding if the upper boundary of the opening 3 is arranged substantially at the level of the incoming material 1, and only the lower boundary of the opening 3 is adjusted in height, the material 1 preferably only to the lower boundary of the opening 3 bounces and is deflected in the direction of the forming belt 12. This avoids that above the opening 3 impinging material 1 falls down and obstructs the passage of the material 1 in the direction of passage 8 at the height of the opening 3 or even blocked.

In the exemplary embodiment, an actuator 17 is shown with a connection 18 to a slider 5 to move the slider 5. The opening 3 is reduced by the movement of the slider 5 from bottom to top and vice versa correspondingly increased when the slider 5 is moved by the actuator 17 down.

In a further embodiment, a further cover plate 4 'may be arranged, which covers the lower region of the slide 5 and at the same time prevents material 2 from entering the interior (outside of the screw trough 19) of the discharge device 2. The further cover plate 4 'can also be arranged on the other side of the slider 5, in order to provide the slider 5 on slipping material 1 no unnecessary friction point.

A pneumatic nozzle 20 can be arranged within the discharge device 2, in order to convey in particular clogging material 1 back into the device 10 or into the screw trough 19.

List of numbers P1588:

1

material

2

discharge

3

opening

4

cover sheet

5

pusher

6

breakthrough

7

rake

8th

Passage direction

9

falling direction

10

device

11

fleece

12

forming belt

13

transport direction

14

distribution roll

15

spreading roller

16

axis

17

actuator

18

Connection 5/17

19

screw trough

20

jet

21

conveyor

Claims (15)

Device for scattering a fleece (11) on a forming belt (12) running endlessly beneath the device (10), in particular in the course of producing material plates of free-flowing material (1) such as fibers or chips, the device (10) comprising: an upper inlet opening for discharging the material (1) and a lower outlet opening for dispensing the material (1) onto the forming belt (12), - At least one distribution roller (14) and a scattering roller (15) transversely to the transport direction (13) of the forming belt (12) and - A discharge device (2) for the partial removal of material (1), wherein the discharge device (2) transversely to the transport direction (13) a plurality of adjustable in size openings (3) are arranged for the deposition of material (1) from the Device (10) with a conveying device (21) for the passing through the openings (3) material (1) are operatively connected,
characterized in that
in the discharge device (2) a cover plate (4) and a plurality of slides (5) are arranged with an opening (6), wherein for adjusting the size of the opening (3), the cover plate (4) partially covers the opening (6) and the cover plate and / or the slide (5) by means of at least one actuator (17) are arranged displaceably. Apparatus according to claim 1, characterized in that in the direction of fall (19) of the material (1) the lower end of the cover plate (4) as the upper boundary of the opening (3) and the opening (6) of a slider (5) as the lower boundary the opening (3) is arranged. Device according to claims 1 or 2, characterized in that in a fixed cover plate (4) for adjusting the opening (3) of the slide (5) with its opening (6) substantially against the material flow direction to reduce the opening (3) and in the material flow direction to increase the opening (3) is arranged movable. Device according to one or more of the preceding claims, characterized in that in the discharge device (2) at least one nozzle (20) for pneumatic cleaning of parts of the discharge device (2), in particular the openings (3) is arranged. Device according to one or more of the preceding claims, characterized in that the cover plate (4) also has an opening and is preferably arranged in a size which substantially covers the range of movement of the slide (5). Device according to one or more of the preceding claims, characterized in that a further cover plate (4 ') the first cover plate (4) opposite to the openings (3) is arranged, wherein preferably the further cover plate (4') the region of the adjustable openings (3) releases but covers the wider area of the slide (5). Device according to one or more of the preceding claims, characterized in that for adjusting the position or the position of the openings (3) in the device (10) the discharge device (2) movable, in particular with respect to the forming belt (12) is arranged vertically adjustable. Method for scattering a fleece (11) on a forming belt (12) endlessly revolving below a device (10) for scattering material (1), in particular in the course of producing material plates from free-flowing material (1) such as fibers or shavings,
wherein material (1) is guided into the device (10) through an upper inlet opening and the material (1) is guided onto the forming strip (12) via a lower outlet opening is and the material (1) substantially distributed by a distribution roller (14) in the apparatus and is transported by means of at least one scattering roller (15) on the forming belt, and
wherein by a discharge device (2) in the device (10) transversely to the transport direction (13) of the endless forming belt (12) piecewise material (1) is removed by several adjustable in size openings (3) the material passing through (1) Feed device (21) for removal from the device (10), characterized in that the adjustable openings (3) of the discharge device (2) by a cover plate (4) and a plurality of slides (5) are formed with openings (6), wherein the opening (6) of a slider (5) for reducing the opening (3) is partially covered by the cover plate (4) by means of at least one actuator (17) the cover plate (4) and / or the slide (5) move become. Method according to the preceding method claim, characterized in that in the falling direction (19) of the material (1) the lower end of the cover plate (4) as the upper boundary of the opening (3) and the opening (6) of a slider (5) as the lower Limitation of the opening (3) is used. Method according to one of the preceding method claims, characterized in that for setting the opening (3) the slide (5) with its opening (6) substantially against the material flow direction to reduce the opening (3) and in the material flow direction to increase the opening (3 ) is moved .. Method according to one of the preceding method claims, characterized in that in the discharge device (2) at least one nozzle (20) for the pneumatic cleaning of parts of the discharge device (2), in particular the openings (3) is used. Method according to one of the preceding method claims, characterized in that the cover plate (4) also has an opening and is preferably used in a size which allows the Movement range of the slide (5) substantially to cover. Method according to one of the preceding method claims, characterized in that a further cover plate (4 ') lies opposite the first cover plate (4) to the openings (3), wherein the further cover plate (4') releases the region of the adjustable openings (3) but the lower portion of the slide (5) covered. Method according to one of the preceding method claims, characterized in that for adjusting the position or the position of the openings (3) in the device (10) the discharge device (2) movable, in particular with respect to the forming belt (12) is arranged vertically adjustable. Method according to one of the preceding method claims, characterized in that the stream of material (1) impinging on the discharge device (2) is guided onto the openings (3) such that the upper part of the stream facing away from the forming belt enters the opening (3). is guided and, depending on the size of the opening (3) of the lower portion of the slider (5) stopped and down in the direction of the forming belt (12) is guided.

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