CN113874182A

CN113874182A - Device for gluing particles in the production of material boards and method for operating the device

Info

Publication number: CN113874182A
Application number: CN202080039057.6A
Authority: CN
Inventors: K·彭斯基
Original assignee: Dieffenbacher GmbH Maschinen und Anlagenbau
Current assignee: Dieffenbacher GmbH Maschinen und Anlagenbau
Priority date: 2019-05-26
Filing date: 2020-05-26
Publication date: 2021-12-31
Anticipated expiration: 2040-05-26
Also published as: WO2020239727A1; DE102019114039A1; CN113874182B; EP3976332A1

Abstract

The invention relates to a device for gluing particles at least partially consisting of fibres and/or chips suitable for producing a material board, comprising: a drop chute (10) having a wall (3) defining the drop chute (10); a dosing device (2) for introducing the particles (1) into the downer (10) and at least one nozzle (6) for applying a binder (11) to the particles (1). The invention mainly comprises the following steps: in the case of a single-layer wall (3), the plastic is arranged as this layer (4), or in the case of a multi-layer wall (3), the plastic is arranged as a first layer (4) on the side of the particles (1) to be glued.

Description

Device for gluing particles in the production of material boards and method for operating the device

The invention relates to a device for gluing particles consisting at least partly of fibres and/or chips suitable for producing material boards according to the preamble of claim 1.

The invention also relates to a method for operating a device for gluing particles, which particles are at least partially composed of fibers and/or chips suitable for producing material boards, according to the preamble of claim 18.

The production of material boards from e.g. chips or medium density fibres or other loose materials is now an automated process and has been used for many years in many countries. As is known, the pressing of the prepared chips or fibers is carried out either periodically or continuously. In addition to the various plant parts before and after the press, the production of a spread mat by means of a spreader also plays a prominent role here, since the quality of the resulting spread mat is an important factor in addition to the quality of the raw material. The pursuit of low cost material boards from natural raw materials and artificially produced binders has forced manufacturers to develop more and more efficient processes. Particularly low downtime and low wear are of particular importance here.

The present description relates to the field of gluing particles with adhesives. Basically, a binder is understood to be a so-called binding material liquid (klebstuffflow), the main component of which consists of the binding material (glue). Emulsion, curing agent, formaldehyde scavenger, dye, insect and mildew preventive and other additives are additionally added according to the needs. It is also common to use adhesive materials that do not contain additives. By way of non-exhaustive example, the binder may be: isocyanate, MDI, Melamine Urea Formaldehyde (MUF), Urea Formaldehyde (UF), MUPF or PF.

Gluing is usually carried out: the bulk material or granulate is introduced into the downer by means of a dosing device and the binder is applied to the bulk material or granulate by means of a nozzle arranged in or upstream of the downer. In most cases, the glued spread is treated and/or further glued in a drum located downstream of the downer with a rotating conveyor means (mechanical mixer), then spread into a spread mat, then immediately pressed, after which the glue hardens. Alternatively, the spread may not be passed through a mechanical mixer, but rather introduced directly into the spreading apparatus to spread the spread mat and then pressed.

Such a device is known, for example, from DE 102010064339 a 1. In these devices, in most cases, the adhesive and the particles glued with the adhesive accumulate at the inner wall of the descending chute, so that the descending chute tends to become dirty over time. This makes it necessary to clean the downer periodically. EP 2563558B 1 discloses an apparatus and a method for cleaning a drop chute, wherein a scraper cleans the inner side of the drop chute. It is also disclosed that the downer is implemented as a double (layer) wall, with cooling liquid passing between the walls to prevent caking of the binder.

Corresponding supply and discharge lines are therefore provided for the cooling liquid, which lines have sufficient conveying capacity. In order to supply the cooling liquid to the walls of the rotating downer and/or to the rotating wiper, corresponding fluid-conducting coupling devices must be provided, which enable the cooling liquid to be transferred from the stationary part of the apparatus to the rotating downer walls and/or the rotating wiper. The mechanical construction required for this may be costly and it may be difficult to achieve a durable, effective seal.

EP 2922670B 1 further proposes an apparatus and a method in which an internally located scraper for cleaning the walls in the descending material path is periodically subjected to a joint cleaning by means of a second cleaning apparatus.

These technical conversions result in high maintenance costs and significantly increase the risk of failure of the device. The above-described solution, which is also basically simplified to a rotationally symmetrical drop chute, cannot always be used in the course of retrofitting a plant for producing material plates with such a drop chute, in particular if corresponding, existing connections or transitions cannot be adapted as appropriate. However, these adaptations again require geometric concessions, which significantly increase the risk of caking.

It is therefore an object of the invention to propose an apparatus which is able to reduce effectively the formation of accretions inside the descending chute. Another object of the invention is to propose a device which can be adapted to various geometries and thus customized at low cost and which can be easily integrated into an already implemented plant.

Furthermore, it is desirable to reduce the downtime during cleaning as much as possible or, where possible, to avoid it completely, particularly preferably at low cost.

An apparatus for gluing particles which are at least partially composed of fibers and/or chips suitable for producing material boards proceeds from an apparatus having: the device comprises a descending channel, a wall defining the descending channel, a dosing device for introducing the granules into the descending channel, and at least one nozzle for applying the binder to the granules.

The object of the invention is achieved for a device in that:

in the case of a single-layer wall, the plastic is arranged as this layer,

or

In the case of a multilayer wall, the plastic is arranged as a first layer on the side (facing) the particles to be glued.

The invention is to be understood as meaning a descending material duct as a hollow body which is open on two opposite sides, wherein the particles can fall through it from top to bottom. In the downer, the particles may also be guided, braked or accelerated by suitable means, for example by means of a rotating spike roller.

The downer is preferably hollow cylindrical, conical or substantially similar in cross-section, having an inner side, and at least one region of the inner side or wall may be in contact with the binder or fibers having the binder.

By "wall" is herein understood a bounding wall surrounding the inner space of the downer, which may have a homogeneous or heterogeneous layered structure, wherein in the case of heterogeneous multilayers the layers are placed next to each other and thereby form a composite.

It can thus be provided that the wall is formed by an inner plastic layer which is particularly well suited to avoid blocking by means of adhesives or glues. The second, outer layer can also be a plastic, for example, which has greater rigidity or toughness than the first, inner layer.

For example, according to the invention, a layer separated by air or by a fluid is to be construed as a multiple of a wall, for example in the case of a double wall, with a fluid passing through for cooling.

The following features may be used cumulatively or alternatively to further improve the device according to the invention.

Here, the plastic may be an elastic polyurethane, an elastomer, or a silicone. These plastics preferably have a low adhesion with respect to the adhesive. At the same time, it has surprisingly been shown that despite the abrasive action of the falling particles, these plastics can nevertheless have sufficient stability for continuous operation.

Preferably, in the case of a multi-layer embodiment, one or the outer layers can be arranged to support the first inner layer of the wall substantially statically. In the case of a two-layer wall embodiment, it is particularly preferred if the outer layer is made of a hard or fiber-reinforced plastic or metal.

Alternatively or cumulatively, the plastic, preferably for a wall with one layer, is arranged with a wall thickness of at least 10 mm. Particularly preferably, the structure of the single-layer wall has the advantage of reducing the electrostatic charge generated by the falling particles.

Particularly advantageously, an exciter, preferably a rapper or a vibrator, is arranged at the wall in order to introduce shocks and/or vibrations. Advantageously, the vibration or shock may prevent the glued particles or adhesive from sticking, thereby avoiding agglomeration.

In a preferred embodiment, the means for coupling the exciter can be arranged non-positively, materially or positively on the wall. Such a coupling improves the stability of the wall or the downer.

In a further alternative or additional development, the device for coupling the exciter can be cast into the wall and/or into the plastic. In this case, a plate, a ring or a housing is particularly preferably arranged as the device. The hoop or housing according to the present invention means a cage which encloses the cross section of the downer or the wall, thereby enabling the wall to vibrate or vibrate uniformly.

In a further preferred alternative or additional embodiment, the plastic can be given or cast with antistatic additives. Advantageously, static charges during operation can thereby be avoided or at least reduced.

In this case, it is advantageous to use a plastic with a wall thickness of 2mm to 10mm, preferably 4mm to 8mm, most preferably 5mm to 7 mm. In this case, important design aspects are the blanking height of the chute, the cross section, the static load-bearing capacity of the plastic and the material to be glued.

In order to increase the strength of the plastic, a fiber-reinforced plastic can be arranged as at least one layer.

The cross section of the downer may decrease in the direction of falling of the material, so that the material is mixed again during falling and is fed specifically into the mixer.

Alternatively or cumulatively, the cross section of the downer may be embodied here, for the reasons mentioned above, to be substantially circular when the particles enter and substantially rectangular when the particles leave.

The invention further provides that the one-piece wall, in which the downer is arranged, is preferably cast or injection-molded from plastic.

If useful or necessary, a scraper can be arranged in the downcast for cleaning the wall located inside. At the scraper blade there may be arranged a knife-like cutting member, preferably made of metal or plastic, or a plastic or rubber lip in contact with the inner layer for cleaning. It is thereby ensured that the surface of the wall or of the inner layer made of plastic is not subjected to excessive loads or scratched. The scraper can be embodied movable and/or the downer or its wall can be embodied movable.

In a particular embodiment, a sliding mechanism can be arranged for the descending chute for actively or passively moving the descending chute from the operating position into the cleaning position and vice versa. Depending on the design configuration, the downer according to the invention can be arranged here as a main downer and/or as a secondary downer.

Thus, the drop chute according to the invention can be used as a replacement drop chute when the main drop chute is cleaned.

Alternatively, the drop chute according to the invention can be used as a complete drop chute if the self-cleaning effect by means of plastic, in particular in combination with the excitation, proves to be sufficient, and if necessary, an alternative drop chute can even be arranged in the same embodiment. Advantageously, the user can save on highly complex cleaning and cooling systems when using a low cost down chute made of plastic.

For this reason, it can also be considered as a replacement or spare part, which is replaced at predetermined time intervals.

To this end, in a further development, it is advantageous to provide a crane or hoist for hoisting the drop shaft into or out of the installation. In a factory, it is not always possible to quickly bring a device for lifting a component out or in to the site.

A solution to the operating method of a device for gluing particles, which particles are at least partly composed of fibres and/or chips suitable for a sheet of material, comprises a descending chute of this type and consists in: the downer is used, wherein in the case of a single-layer wall, plastic is used as this layer, or in the case of a multi-layer wall, plastic is used as the first layer on the side of the (facing) particles to be glued, and wherein the downer is replaced at predefined time intervals or in the case of being too dirty. For example, contaminants or cleaning process substances may damage the inner wall of the downer. In this respect, it seems sensible to provide the drop shaft as a replacement module and not only to clean it regularly, but also to replace it. Especially if a mold for the original equipment already exists for this purpose.

In this case, it may be advantageous for the method if, during the replacement, the first drop shaft is lifted out of the machine frame against the falling direction, the second drop shaft is lifted into the machine frame in the falling direction. In particular, a corresponding frame device is preferably provided in the device, in which the descending material path can be suspended at a predetermined and mechanically fixed position.

Further advantageous measures and embodiments of the subject matter of the invention are set forth in the dependent claims and in the following description with the drawings.

The figures show:

figure 1 shows a schematic side view of the dosing device, the downpipe and the mixer in a cross-sectional view,

fig. 2 shows part II in an enlarged view of a single-layer wall according to fig. 1, an

Fig. 3 shows a section III in an enlarged view of the multilayer wall according to fig. 1.

An apparatus for gluing pellets, which may consist essentially of chips and/or fibres, and which are subsequently pressed for producing boards of material or similar mouldings is illustrated. In the factory for producing material boards, the granules 1 arrive here in a dosing device 2, which dosing device 2 is embodied according to the present embodiment as an endless circulating conveyor belt. Means (not shown) may be provided which adjust or regulate the discharge of the granules 1 per unit of time, for example a discharge roller. In the downer 10, after the particles leave the dosing device 2, a particle curtain 5 is formed, which particle curtain 5 is sprayed with a binder 11 by means of a nozzle 6.

There are other features in the prior art that can significantly improve the present embodiment. In particular, according to the prior art, the descending chute 10, or at least the lower part below the nozzle 6, can be moved, so that cleaning is easier. In this case, it may also be useful to provide another drop shaft 10 instead.

In the further course, after the binder 11 has been sprayed by means of the nozzle 6 at the lower end, the granules 1 leave the downer 10 and are transferred for other use or, as in this embodiment, directly to the mixing device 7. Such a mixing device 7 is embodied here as a horizontal mixer with mixing tools 8 at a rotating shaft 9 and the particles 1 are discharged correspondingly mixed at the other end.

In order to avoid the need for cleaning a new descending material path regularly, the walls 3 of the descending material path are activated at predetermined time intervals or continuously by means of the activator 14. The excitation may be transmitted directly to the wall 3 of the downer 10 or, as shown, to the wall 3 by means 15 for introducing pulses or vibrations. Particularly preferably, the means for introducing the excitation can be embodied circumferentially along the wall 3, so that the impact or shock is distributed uniformly over the circumference. At the level of the downer 10, a plurality of positions for introducing excitation can also be provided.

In another embodiment according to fig. 2, which shows an enlarged section II according to fig. 1, the means for introducing the excitation from the exciter 14 are integrated into the layer 4 of the wall 3, preferably into the plastic of the wall 3. In this exemplary embodiment, the wall 3 is embodied as a single layer and has a wall thickness 13.

Particularly preferably, the means for introducing the excitation are embodied circumferentially along the wall 3, so that the impact or vibration is distributed uniformly over the circumference. A plurality of positions for introducing excitation can also be provided in the height of the downer 10.

In a third example according to fig. 3, showing an enlarged portion III according to fig. 1, the wall 3 is shown as a multi-layer embodiment, here two layers, wherein the inner layer 4 consists of plastic and the outer layer 12 consists of another solid material, a second plastic or a metal plate. Advantageously, the metal sheet no longer has to be made of an expensive and corrosion-resistant material, such as stainless steel, but can also be made of an inexpensive tool steel. Here too, a wall thickness 13 is present, which is formed by the thicknesses of the

layers

4 and 12.

List of reference numerals: 1600

1. Granules

2. Dosing device

3. Wall(s)

4. Layer (inside of 3)

5. Particle curtain

6. Nozzle with a nozzle body

7. Mixing device

8. Mixing tool

9. Shaft

10. Descending material channel

11. Binder

12. Layer (outer)

13. Wall thickness

14. Exciter

(for introduction) device

Claims

1. An apparatus for gluing particles, which particles are at least partly composed of fibres and/or chips suitable for producing a material sheet, comprising a descending chute (10) having a wall (3) delimiting the descending chute (10); -dosing means (2) for introducing particles (1) into the downer (10); and at least one nozzle (6) for applying a binder (11) to the particles (1),

in the case of a single-layer wall (3), the plastic is arranged as this layer (4); or

In case of a multilayer wall (3), the plastic is arranged as a first layer (4) on the side of the particles (1) to be glued.

2. The device of claim 1, wherein an elastic polyurethane, elastomer, or silicone is disposed as the plastic.

3. The apparatus as claimed in one of the preceding claims, characterized in that, in the case of a multi-layer embodiment, the outer layer (12) is arranged to support the first inner layer (4) of the wall (3) substantially statically.

4. Device according to any of the preceding claims, characterized in that the plastic, preferably for a wall (3) with one layer (4), is arranged with a wall thickness (13) of at least 10 mm.

5. Device according to any of the preceding claims, characterized in that an exciter (14), preferably a rapper or a vibrator, is arranged at the wall (3) for introducing shocks and/or vibrations.

6. The device as claimed in any of the preceding claims, characterized in that the means (15) for coupling the exciter (14) are arranged force-fittingly, material-fittingly or form-fittingly in the wall (3) or at the wall (3).

7. The device according to any one of the preceding claims, characterized in that the means (15) for coupling the exciter (14) are cast into the wall (3) and/or into the plastic, and preferably consist of a plate, a ring or a housing.

8. The apparatus as claimed in any one of the preceding claims, wherein the plastic has an antistatic additive.

9. The device according to claim 8, characterized in that the plastic is arranged to have a wall thickness (13) of from 2 to 10mm, preferably 4 to 8mm, particularly preferably from 5 to 7 mm.

10. The device as claimed in any of the preceding claims, characterised in that fibre-reinforced plastic is arranged as at least one of the layers (4, 12).

11. The apparatus according to any of the foregoing claims, characterised in that the cross-section of the downer (10) decreases in the falling direction of the material (1).

12. The apparatus according to any of the foregoing claims, characterised in that an integral wall (3) of the downer (10) is arranged, which is preferably cast or injection moulded from plastic.

13. The apparatus according to any of the foregoing claims, characterised in that the cross-section of the downer (10) is embodied so as to be substantially circular when the particles enter and substantially rectangular when the particles leave.

14. The apparatus according to any of the preceding claims, characterized in that a scraper made of metal or plastic is arranged in the downer (10) for cleaning the wall (3) located inside, wherein preferably the scraper is arranged with a blade-like cutting member made of metal or plastic and/or, most preferably, a plastic or rubber lip is arranged at the scraper in contact with the layer (4) for cleaning.

15. The apparatus according to any of the foregoing claims, characterised in that a sliding mechanism for the downer (10) is arranged for active or passive movement from an operating position into a cleaning position, and preferably that the downer (10) is arranged as a main and/or as a secondary downer.

16. The apparatus as claimed in any one of the preceding claims, characterized in that the downer is arranged to be replaceable, preferably by means of a quick clamping device.

17. An apparatus according to any one of the preceding claims, wherein a crane or hoist is arranged for hoisting the downer into or out of the apparatus.

18. A method of operating an apparatus for gluing particles, which particles are at least partly composed of fibres and/or chips suitable for producing a material sheet, the apparatus comprising: a drop chute (10) having a wall (3) defining the drop chute (10); -dosing means (2) for introducing particles (1) into the downer (10); and at least one nozzle (6) for applying a binder (11) to the particles (1),

it is characterized in that the preparation method is characterized in that,

using a drop chute (10), wherein, in the case of a single-layer wall (3), plastic is used as this layer (4), or

In the case of a multi-layer wall (3), plastic is used as the first layer (4) on the side of the granules (1) to be glued, and wherein the descending chute (10) is replaced at predefined intervals or in the case of being too dirty.

19. The method of claim 18,

the first drop chute (10) is lifted out of the machine frame against the falling direction and the second drop chute (10) is lifted into the machine frame in the falling direction.