EP2994277A1

EP2994277A1 - Method and apparatus for gluing chips, fibers or fiber-like material in the course of the production of material boards

Info

Publication number: EP2994277A1
Application number: EP14725391.8A
Authority: EP
Inventors: Helmut Bauser; Detlef Kroll; Gernot Von Haas
Original assignee: Dieffenbacher GmbH Maschinen und Anlagenbau
Current assignee: Dieffenbacher GmbH Maschinen und Anlagenbau
Priority date: 2013-05-06
Filing date: 2014-05-06
Publication date: 2016-03-16
Also published as: CN105228801A; WO2014180867A1; DE102013104652A1

Abstract

The invention relates to an apparatus and to a method for gluing chips (24) in a mixing apparatus (22) having pressure conditions corresponding substantially to the ambient pressure, or for gluing fibers (2) or for gluing fiber-like material in a transport pipe (1) loaded by a conveying means (20) having pressure conditions corresponding substantially to the ambient pressure, by using a binder (5) in the course of the production of fiber boards, MDF boards, HDF boards or fiber insulation boards, wood material or plastic boards, comprising a mixing apparatus, (22) or a transport pipe (1), and at least one nozzle (3), wherein the nozzle (3) can be connected via at least one opening (23) to the mixing apparatus (22) or a transport pipe (1) and at least one binder line (16) having a pump (32) for delivering and spraying binder (5), preferably from a supply line or supply tank, is arranged on the nozzle (3). According to the invention the apparatus has a further pump (33) having a hardener line (37), which pump (33) is arranged in operative connection and is preferably suitable to be controlled via the flow of the hardener (34) or of the binder (5).

Description

The invention relates to processes for the gluing of chips, fibers or. The invention relates to processes for gluing chips, fibers or fiber-like material

fiber-like material in the course of the production of material plates according to the preamble of claim 1 or 2 and a device for gluing according to the preamble of claim 8. The production of material plates from, for example, chips or medium-density fibers or other free-flowing materials are now automated

Processes and are already used in many countries for years. As is known, the compression of processed chips or fibers takes place either clock-bound or continuously. In addition to the many plant components before and after the press, the production of a spreading material mat using spreading machines plays a role here

outstanding role, since the quality of the grit mat created is an important factor in addition to the quality of the raw materials. In the large-scale industrial production of wood-based panels are continuously working presses, but sometimes still single or multi-day presses used. The urge to produce cost-effective material panels from natural raw materials and artificial

Produced binder forces producers to develop more and more efficient processes. Special emphasis is placed on energy costs, raw material and binder savings with consistent quality and technically optimized plant construction with low downtime and low wear.

The present elaboration refers to the area for the optimization of the

Binder consumption and, consequently, with the saving of

Energy costs. Because with optimum gluing with low moisture content not only lower costs result from binder consumption, but it also has less binder in the dryer on the chips / fibers are dried, which in turn saves energy and thus costs. Basically one understands under

Binder a so-called adhesive fleet, which consists in its main component of an adhesive. Depending on requirements, emulsion, hardener,

Formaldehyde scavengers, dyes, insect repellents and antifungal agents and others Added additives. It is also common to use the adhesive without additives. In this case, the hardener, if it is necessary, usually added separately in the mixing devices, so that the binder mixed together with the hardener.

The following are suitable as binders without any claim to completeness: isocyanates, MDI, melamine urea formaldehyde (MUF), urea formaldehyde (UF), MUPF or PF.

Basically underlying state of the art is therefore the gluing of chips or fibers by means of spray nozzles in production plants for chipboard or fiberboard. The nozzles shred the binder and spray it on moving chips or fibers. Here, a distinction is made between three methods of gluing, the spraying process on rotationally mixed chips, on falling or accelerated chips, or on fibers moving at high speed in a transport tube.

The chips are usually already delivered as chips or produced on site and fed to the gluing before or after drying. Fibers are made by Zerfaservorrichtung usually on site and conveyed after the defibration between two grinding discs through a transport tube (English: Blow Line) to a dryer. Depending on the size and structure of the system, the transport tube may have a length of up to 100m. During transport, which is preferably carried out at very high speed in a small diameter tube, the fibers are glued and then conveyed to a dryer for drying.

Subsequently, the chips or fibers are scattered on documents and pressed by pressing to sheets of material.

Usually, the necessary binder for gluing with nozzles in the transport tube or a mixing device (Beleimtrommel rotating and / or moving mixing elements) is introduced, which dissolve the binder during atomization as small as possible.

With DE 10 2008 059 877 A1 and later with DE 10 201 1 007 336 A1, methods and devices for gluing chips, fibers or fiber-like material have become known, with which the binder with steam before it leaves the nozzle be mixed. The high temperature of the steam as well as the extremely turbulent flow in the mixing chamber of the nozzle for an optimal resolution of the

Binders care. This is particularly advantageous in the case of high-pressure glueing since, given an existing pressure in the transport tube, a "blow-line" should preferably be injected at a higher pressure than in the transport tube

Pressure difference, but the optimal distribution within the transport tube or the mixing device are crucial criteria. It has been found that especially the binders, MDI, UF, MUF and PF in liquid or suspended (semi-liquid) or dispersed form for a spraying with present

Method or device are suitable.

In principle, these methods and devices have been proven, but it has been shown that the proposed introduction of an adhesive liquor, which is already mixed with a hardening agent, tends to harden before dissolution with steam and clog the supply lines of the adhesive liquor and cause business failures due to lack of gluing being able to lead. In particular, the steam can bounce back in the binder feed and contribute there to early curing. Also, it is problematic to provide an adhesive liquor with hardener near warm or hot

Equipment.

The alternative side, separate application of binder and hardener on the materials to be glued usually has the disadvantage that regular

Overdoses of one or the other component take place and that it may also happen that the components in the respective need (mixing ratio) do not find each other. So it can be to Ausplatzern

(Dampferuptionen) come after the press, if the binder is not cured in time because of lack of hardener and the plate is unable to withhold the steam for lack of internal strength. Pure hardener areas act as notches in later panels because there is no binder and therefore also lack the necessary internal bond. It is an object of the present invention to provide a method and an apparatus for gluing chips and / or fibers, which avoids the above disadvantages. The solution to this problem is for a method in that the hardener is metered by means of another pump supplied to the binder in the binder line or in the nozzle.

A second solution for the process for a vapor-based gluing is that the hardener for the binder in the steam line or in the mixing space of the nozzle, preferably flow-controlled, is metered.

The solution to this problem is for the device for gluing in that for the addition of hardener to the binder in the binder line or in the nozzle in operative connection with another pump with a hardening line is arranged, which is preferably suitable for the flow of the hardener or the Binders to be regulated.

Advantageously, it is now possible as a teaching of the invention that in the case of a short-term plant stop no immediate flushing of the binder lines is more necessary, preferably if the addition of the curing agent before the stop of the

Binder is stopped. Furthermore, it is now possible to adjust the dosage again more precisely, which is not so easy with a separate addition of binder and hardener. Hardener is usually mixed with separate addition additionally with water, which must be considered in the course of the production of material plates in terms of moisture fluctuations and actually not wanted, since it increases the drying effort, especially in the MDF production. Particularly preferably, the hardener should be mixed with the binder directly in the nozzle. In particular, it is preferred and advantageous if the hardener before the

Contact with the binder is already dissolved by steam and finely dispersed. Finally, it is also advantageous if the steam has already dissolved the binder or if these three individual elements, individually or combinatorially, are brought together in a mixing chamber. Preference is given to the individual shares regulated by the pressure and / or by their flow rates, in particular their proportions to each other.

In an annular gap nozzle according to FIGS. 1 and 2, it is particularly advantageous that a low steam consumption is necessary, the steam can be switched off and the nozzle can only be used as a pressure nozzle and the atomization pressure of the binder can be regulated via the adjustment of the annular gap or the opening.

Particularly preferred mixing blades are arranged in the mixing chamber, which mix in the sense of a static mixer, the flowing material.

It is also particularly preferred if pumps are used for the supply of the hardener and / or the binder, which can be driven pulsating, for example by a pulse generator. By using them in front of each nozzle, it is ensured that each nozzle can be supplied with a precise controllable amount of hardener or binder. This ensures that each binder droplet also has the correct and necessary amount of hardener.

A nozzle is advantageously designed so that the mixing space, which is suitable to produce the vapor-binder mixture, can be separated from the steam line or from the supply of the hardener.

In particular, it has surprisingly been found and it is now of advantage that the reaction time of the hardener with the binder can now be determined better in time and overall is uniform, so that now better board qualities can be achieved due to the uniform curing

It is also of direct advantage that said device in the nozzle area can be easily or automatically cleaned, in particular prophylactically. Also, blockages or jamming on the nozzle head are excluded or can be eliminated easily by the associated actuator. However, a self-cleaning effect is provided by the vapor flow or binder flow when it is turned on. In combination or as stand-alone further preferred embodiments: the binder and the hardener can be mixed in a mixing space, preferably by means of static mixing elements.

the metering or the flow rate of the hardener can be regulated as a function of the flow rate of the binder,

The hardener can be added pulsating.

the switching on and off of the hardener and / or the steam and / or the binder and / or the nozzle can be controlled or regulated by means of a control or regulating device.

- The binder or the binder line can be cooled at least from the addition of the curing agent.

For this purpose, it is preferably provided as a stand-alone feature or in combination that a mixing space, preferably with static mixing elements, is arranged in the binder line or in the nozzle.

that the pump is suitable to dose the hardener pulsating.

that cooling on the binder line at least from the supply of the

Hardener is arranged.

that at a nozzle with a steam line and a mixing chamber for

Mixing of the binder with steam a hardening line with associated

Pump is arranged in operative connection with the steam line and / or the mixing chamber.

The device is suitable for carrying out the method, but can also be used alone.

Further advantageous measures and embodiments of the subject matter of the invention will become apparent from the dependent claims and the following description with the drawing.

Show it:

Figure 1 shows a section through a device according to a first

Embodiment in the high pressure area with a transport tube and a nozzle proposed by way of example FIG. 2 shows an enlarged view of the transition from the mixing chamber into the transport tube according to FIG. 1,

3 shows a section through a device according to a second

Embodiment in the normal pressure range with a mixing device and an exemplary nozzle,

Figure 4 shows a simplified arrangement of a schematic nozzle, respectively

associated lines in a first embodiment,

FIG. 5 shows a further embodiment variant according to FIG. 4,

Figure 6 shows a further embodiment variant with an additional steam line after

FIG. 4,

FIG. 7 shows an exemplary cooling arrangement of a supply line without a nozzle in a

Transport pipe and

FIG. 8 shows a variant of the nozzle according to FIG. 1. Figures 1 and 2 show a fundamentally possible structure of a device, inter alia, for carrying out the method, consisting of a

Transport tube 1 with a wall 10, within which with a flowing

Conveyor 20, the fibers 2 are transported past at least one nozzle 3 over. On a representation of several nozzles 3 on the transport tube 1 has been omitted for clarity. Next, the relation of the size of the transport tube 1 to nozzle 3 or wall 10 is not reproduced to scale. The nozzle 3 has an adjusting device 4, which is in operative connection with a nozzle head 12, in the example via a plunger 11. The adjusting device 4 is thus able to regulate or close the size of the opening 23 via the nozzle head 12. The adjusting device 4 is not limited in its design and concerning the choice of many options (linear conveyor, crank, ball or rack and pinion, indirect drive ....) by the skilled person to design in detail.

It should be emphasized that in the nozzle 3, a mixing chamber 7 is arranged in the separated steam 6 via a steam line 17 and binder 5 via a

Binder line 16 can be supplied. Fluid and high pressure technical

Embodiments (high-pressure pumps, conveying means, steam production, steam line, non-return valves, pressure gauges) are likewise within the scope of the ability of a corresponding specialist who determines and installs those standard components which are possible or necessary according to the technical state of the art. During operation, in the mixing chamber 7, adjacent to the opening 23 and thus the transition to the transport tube 1, a vapor-binder mixture 15, which is preferably mixed under a predetermined pressure by a pressure preset 25 on the control or regulating device 9. The control or regulating device 9 controls or regulates the position of the nozzle head 12 via the adjusting device 4 and thus the size of the opening 23 on the basis of a pressure preset 25 or by means of a measurement result by the measuring device 8 or in the mixing chamber 7 Control or regulation, the device has a plurality of measurement points. For example, the pressure in the mixing chamber 7 with a

Measuring device 8 and / or the pressure in the binder line 16 with a

Measuring device 14 and / or the pressure in the steam line 17 with a

Measuring device 18 and / or the pressure in the transport tube 1 and in the

Mixing device 22 with a measuring device 13 determined. For further optimization of the method, the pressure in the mixing chamber 7 and / or the size of the adjustable opening 16 can be controlled or regulated as a function of the amount of binder 5 to be introduced into the transport tube 1 via a control or regulating device 4. In this regard, a corresponding dependence on the

Flow rate of the fibers 2 are set or regulated.

Preferably, the binder 5 can be supplied to the mixing chamber 7 with a lower pressure than the steam 6. This is advantageous in the resolution and

Expulsion of the binder from the mixing chamber 7 by the steam.

In order to mix the hardener 34 in terms of process technology favorably with the binder 5, a hardening line 37 is shown, which opens directly into the steam line 17 of the steam 6. The steam dissolves the hardener and the steam-hardener mixture is introduced into the mixing chamber 7, where further the binder 5 is dissolved. Alternatively or in combination, the hardener line can also directly into the

Mixing chamber 7 or open into the binder line 16.

In Figure 3 is a section through a device according to a second

Embodiment in the normal pressure range shown with a mixing device 22. The mixing device consists of a fixed drum 29 having an input for chips 24 on one side and an outlet for the glued chips 24 on the other side. The direction of the arrow shows the direction of passage of the chips 24, the mixing blades 27 on a mixing shaft 26, driven by a Motor 28 are mixed and conveyed in the mixing device 22. In the upper part of a nozzle 3 in section and on the back of the opening 23 of another nozzle 3 is shown. In dashed form, another set of nozzles 3 is shown. In the context of the invention, of course, only one nozzle 3, possibly also only in

Entrance area, be arranged. The nozzle head 12 defines the opening 23 of the nozzle 3 and is moved via the adjusting device 4.

Preferably, in a mixing device 22, the steam 6 is introduced into the mixing chamber 7 in the steam line 17 at 3 to 16 bar absolute. In another

Embodiment can be introduced into the mixing device 22 to promote the gluing in the mixing device 22 via an additional steam line 19 additional steam 21. The additional steam vapor line could also be injected from below into the drum 29 in order to stir up the chips.

Here, too, it is shown that a hardener line 37 is arranged on the nozzle 3 in order to mix the hardener 34 directly with the steam 6 and / or the binder 5.

Preferably, the connection and disconnection of the steam 6 and the position of the steam valve 30 is controlled or regulated via a predetermined pressure in the mixing chamber 7 via a control or regulating device 4. The pressure can be controlled or regulated in the mixing chamber 7 and / or the size of the adjustable opening 16 as a function of the amount of fibers 2 / chips 24 to be penetrated in the transport tube 1 or in the mixing device 22 via a control or regulating device 4. In particular, for measuring the pressures in or on the mixing chamber 7, a measuring device 8 and / or in or on the binder line 23, a measuring device 14 and / or in or on the steam line 17, a measuring device 18 and / or in or on the transport tube 1 and Mixing device 22 may be arranged a measuring device 13. It is also useful to control or regulate the size of the opening 23 and / or the steam valve 30 to arrange a control or regulating device 4. Also, in order to control or regulate the pressure in the mixing chamber 7 and / or the size of the adjustable opening 16 and / or the steam valve 30 for controlling the amount of steam in dependence on the amount of binder 5 to be introduced into the transport tube 1 or the mixing device 22, a control or control device 4 can be set up. Particularly preferred as a steam valve 30 in the steam line 17, a slide or a ball valve is arranged. The steam valve 30 the steam line 17 can be designed for direct separation at the mixing chamber 7 and / or at least in one piece with the nozzle 3.

In addition to the pressure control is a ratio control of steam, hardener and

Binder usually necessary so that any flow or flow meter are arranged. In particular, for adjusting the mixing ratio binder hardener to each other.

Figures 4 to 6 show alternative nozzle and line arrangements for

Mixing of the binder 5, which is conveyed via a pump 32 in the binder line 16. Static mixing arrangements 7 for the out of the hardener line 37 with the

Pump 33 metered hardener 34 are shown by dashed lines and optional. The hardener

Binder mixture finally passes into the nozzle 3 and is sprayed there.

According to FIG. 5, it can be provided that the hardener is also mixed and discharged directly in the nozzle, which is a preferred embodiment, with the binder, preferably in an optional static mixing space 7 (dashed line).

At 35, a pulse generator for the pump 33 is shown, which is a clocking or pulsed

Entry of the hardener 34 in the binder 5 should reach.

Figures 6, 7 and 8 are schematic overview drawings of

Embodiments are in which in a nozzle 3 and a device of the hardener

34 is mixed via a hardener line 37 with the other components.

If in the described preferred embodiments, the transport tube 1 for the gluing of fibers or fiber-like material and the mixing device 22 is provided for the gluing of chips, so this is not limiting, but there are a variety of devices or mixers or

Mixing devices that can benefit from an application of the proposed nozzle and the proposed method. 1458 List of Reference Numerals: P1458

1. transport tube 20. funding

2. Fibers 21. additional steam

3. Nozzle 22. Mixing device

4. Actuator 25 23. Opening

5. Binder 24. Chips

6. Steam 25. Pressure preset for 7

7. Mixing chamber 26. Mixing shaft

8. Measuring device 27. Mixing blades

9. Control device 30 28. Engine

10. Wall 29. Drum

1 1. ram 30. steam valve

12. nozzle head 31. cooling

13. Measuring device 32. Pump for 5

14. Measuring device 35 33. Pump for 34

15. Steam-binder mixture 34. Hardener

16. Binder line 35. Pulse generator for 33

17. Steam line 36. Mixing elements

18. Measuring device 37. Hardener line

19. Additional steam line

Claims

claims

1. A method for gluing chips, fibers or fiber-like material, in particular in a plant for the production of chips, fiber, MDF, HDF or Faserdämm-, derived timber products or plastic plates, wherein the binder (5) with a pump (32 ) is supplied to a nozzle (3) for spraying through a binder line (16), dad urch

geken nzeich net, that the hardener (34) by means of another pump

(33) metered into the binder (5) in the binder line (16) or in the nozzle (3) is supplied.

2. A method for gluing chips, fibers or fiber-like material with at least one nozzle (3), wherein the binder (5) in a mixing chamber (7) of the nozzle (3) with steam (6) to a vapor-binder mixture (15) is mixed and the vapor-binder mixture (15) in a transport tube (1) or a mixing device (22) via a, in particular adjustable, opening (23) dissolved and with the fibers (2) and / or the chips (24) in contact is brought, dad urch that the hardener

(34) for the binder (5) in the steam line (17) or in the mixing chamber (7), preferably flow-controlled, is metered.

3. Method according to claim 2 or 3, characterized in that the binder (5) and the hardener (34) are mixed in a mixing chamber (7), preferably by means of static mixing elements (36).

4. The method according to one or more of the preceding claims,

dadu rch gekennzeich net that the dosage or the flow rate of the curing agent (34) depending on the flow rate of the binder (5) is controlled.

5. The method according to one or more of the preceding claims,

dadu rch gekennzeich net that the curing agent (34) pulsating (33) is added.

6. The method according to one or more of the preceding claims ,, dadu rch geken net nets that the connection and disconnection of the hardener (34) and / or the vapor (6) and / or the binder (5) and / or the nozzle (3) is controlled or regulated via a control or regulating device (4).

7. The method of claim 1, dad urch in that the binder (5) or the binder line (16) at least from the addition of the curing agent (34) is cooled.

8. Apparatus for gluing chips (24) in a mixing device (22) with substantially the ambient pressure

Printing conditions or gluing of fibers (2) or gluing of fiber-like material in one with a conveying means (20)

acted upon transport tube (1) with substantially the ambient pressure exceeding pressure ratios with a binder (5) in the course of the production of fiber, MDF, HDF or Faserdämm-, derived timber products or plastic plates, consisting of a mixing device (22) or a transport tube (1) and at least one nozzle (3), wherein the nozzle (3) via at least one opening (23) with the mixing device (22) or a transport tube (1) is connectable and at the nozzle (3) at least one

Binder line (16) with a pump (32) for the passage and

Spraying of binder (5), preferably from a supply line or a tank, is arranged so that net for addition of hardener (34) to the binder (5) in the binder line (16) or in the nozzle ( 3) in operative connection with a further pump (33) with a hardener line (37) is arranged, which is preferably suitable to be regulated via the flow of the curing agent (34) or the binder (5).

9. Apparatus according to claim 8, characterized dad urch gekennzeich net that in the binder line (15) or in the nozzle (3) a mixing chamber (7), preferably with static mixing elements (36) is arranged.

10. Device according to claims 8 or 9, dad urch geken nzeich net, that the pump (33) is suitable for metering the hardener (34) pulsating.

11. Device according to one of claims 8 to 10, d a d u r c h

geken nzeich net that a cooling (31) on the binder line (15) is arranged at least from the supply line of the curing agent (34).

12. Device according to one of claims 8 to 11, dadu rch

that a nozzle (3) with a steam line (17) and a mixing space (7) for mixing the binder (5) with steam (6) a hardening line (37) with associated pump (33) in operative connection with the Steam line (17) and / or the mixing chamber (7) is arranged.