EP2101970B1 - Installation for applying glue to fibers for the production of fiberboard - Google Patents

Description

The invention relates to a system according to claim 1 for gluing fibers for the production of fiberboard, especially MDF boards or the like wood-based panels, with a Faserzuführeinrichtung with at least one acted upon with conveying air for the fiber transport fiber feed line, which z. B. an arcuate Faserumlenkleitung opens into a fiber outlet tube, with a downstream of the fiber outlet tube chute, with a z. B. arranged between the fiber outlet tube and the chute gluing device with spray nozzles for spraying emerging from the fiber outlet tube and entering the chute fibers with glue drops and with a chute downstream collecting device with a transport device for collecting and optionally discharging the fibers and a suction device for suction Air from the chute through the conveyor belt. - The transport device is preferably as an air-permeable conveyor belt, z. B. screen belt, is formed, wherein the suction device is arranged below the conveyor belt. Furthermore, a jacket air supply device is preferably provided below the gluing device and consequently in the upper region of the chute with one or more jacket air ducts for generating a jacket air flow surrounding the fiber flow in the chute. By means of the suction device, both the conveying air and the jacket air are sucked through the air-permeable conveyor belt. Consequently, there is a pneumatic supply of the fibers, which enter from the usually vertically arranged fiber outlet tube in the region of the gluing device. There they are treated by means of the spray nozzles with glue drops. The fibers then fall through the chute to the arranged below the chute conveyor belt. Come on this conveyor the glued fibers to rest. Optionally in the chute sinking unused glue reaches the arranged on the conveyor belt fibers, so that a complete Leimausnutzung is ensured and contamination of the system can be reliably avoided by unused glue. MDF boards means medium density fiber boards.

Beleimen for fiber for the production of fiberboard of the type described above are for example from the DE 102 47 412 A1 . DE 102 47 413 A1 . DE 102 47 414 A1 and DE 10 2004 001 527 A1 known. In the known systems, the spray nozzles are arranged on at least one nozzle ring surrounding the fiber stream emerging from the fiber outlet pipe or they form a nozzle ring surrounded by the fiber stream. The angle of attack of the spray nozzles against the fiber flow and / or the distance of the spray nozzles from the fiber flow is adjustable. In addition, the spray nozzles can be changed in position, z. B. slidably disposed on the nozzle ring. Thus, the known system allows an adjustment of the spray nozzle position to the requirements. The extent known measures have proven in principle, but they are capable of further development.

The invention has for its object to provide a system of the type described above, with which fibers for the production of fiberboard MDF boards in particular can gleam properly in a rational and economical manner. In particular, soiling of the system should be avoided and proper operation guaranteed.

To solve this problem, the invention teaches in a generic system for gluing fibers for the production of fibreboard of the embodiment described above, that the spray nozzles or at least some of the spray nozzles from a waiting position in a working position for gluing the fibers are convertible and vice versa. For this purpose, the spray nozzles (or some of the spray nozzles) are preferably attached to pivot levers and can be pivoted with these pivoting levers from the waiting position into the working position and swung out of the working position into the waiting position.

The invention is based on the recognition that a perfect gluing is guaranteed and, above all, soiling and system dysfunctions can be reliably avoided if it is ensured that the spray nozzles are not "permanently" arranged in the gluing area, but the possibility exists of the spray nozzles only if necessary in the Beleimungsbereich and consequently in the working position. Thus, in the context of the invention, the possibility that the spray nozzles are usually positioned as the starting position in their waiting position and are only pivoted into the working position, when actually fibers from the fiber outlet tube enter the chute and thus must be glued. If, for structural reasons, the risk exists that outside the gluing operation glue from the nozzles penetrates, z. B. drips, the invention ensures that such unwanted glue drops do not enter the Beleimungsbereich and in particular not in the chute or on the downstream conveyor belt, but can be collected outside the actual Beleimungsbereiches. Moreover, the arrangement of the spray nozzles in a waiting position that easy and proper maintenance or repair of the nozzles is possible because they can be moved out of the work area in a simple manner and thus easily accessible for repair or maintenance. In this connection, the invention proposes that each spray nozzle is fastened individually to a pivoting lever, wherein the individual pivoting levers can be pivoted in and out individually or together or in groups. In this way, there is the possibility that the operation of the majority of the spray nozzles is pivoted at their pivoting levers in the working position and only individual spray nozzles with their Swing levers remain in the waiting position, so that maintenance or repair can take place even during operation of the system. Because within the scope of the invention preferably a plurality of spray nozzles are arranged on the nozzle ring, z. B. 10 to 20 spray nozzles. The arrangement is preferably made so that, taking into account the spray characteristics of the spray nozzles, a complete spraying over the entire circumference takes place, with excessive overlaps of the individual sprays to be avoided.

In an advantageous embodiment, the invention proposes that the pivot levers are pivotable by means of rotary actuators, preferably each individual pivot lever is associated with a separate pivot drive, it is expedient if each individual pivot drive is controlled separately. These part-turn actuators can be used as pneumatic or hydraulic drives, eg. B. be designed as linear actuators, which are connected to the rotatably mounted pivoting lever. For this purpose, it is expedient if the pivot levers each have at least one pivot arm and at least one articulation arm. To the swivel arm z. B. the end of the spray nozzles connected, while at the Anlenkarm a corresponding pivot drive is connected. The pivot lever may be formed as a substantially L-shaped pivot lever. The part-turn actuators, z. As the pneumatic linear actuators or pneumatic cylinder piston assemblies can be suspended even pivotally or movably on a corresponding frame.

Of particular importance is - as already explained - that in case of a "dripping" of the glue nozzles can be reliably prevented that this glue gets into the chute. In this context, it is expedient if the spray nozzles are associated with one or more drip pans, which are arranged in the waiting position below the respective spray nozzle. It may be appropriate, every single spray nozzle its own Assign catch tray, but it can also be provided drip pans for multiple spray nozzles. In any case, there is no possibility to collect the glue leaving the spray nozzles outside of the gluing operation in the drip pans and to remove it and if necessary to reuse it. In this way, contamination of the system are particularly reliably avoided. In addition, a particularly high Leimausnutzung done.

In a preferred embodiment, the invention proposes that the spray nozzles are connected to a control device which pivots the spray nozzles in the glueing operation from the waiting position to the working position and (automatically) swings out of the working position in the waiting position when interrupting the gluing operation. For this purpose, at least one fiber sensor detecting the gluing operation can be connected to the control device, which is arranged in the region of the fibers entering the chute from the fiber outlet tube. This fiber sensor can be designed as an optical sensor. The invention is based on the recognition that it is expedient to first hold the spray nozzles in the waiting position and only to permit pivoting into the working position, even if fibers from the fiber outlet tube actually enter the chute through the gluing area. A corresponding signal for the control device, which indicates the gluing operation, can in principle be tapped from any area of the installation, it only being necessary for this signal to contain the information that fibers are being transported. It is particularly useful, however, to work with the described sensor.

The spray nozzles are formed in a conventional manner as two-fluid nozzles and connected to a glue supply line and to a first compressed air line for the atomizing air. According to a further proposal of the invention it is now provided that the spray nozzles at least have a movably guided cleaning pin, which is preferably guided movably within the outlet opening of the nozzle, so that by actuation of this pin, a clogging of the nozzle opening can be prevented or additions can be broken. For this purpose, a second compressed air line is provided at the nozzle, which supplies control air for this cleaning pen.

Fig. 1

eine erfindungsgemäße Anlage zum Beleimen von Fasern in vereinfachter schematischer Darstellung,

Fig. 2

einen vergrößerten Ausschnitt aus dem Gegenstand nach Fig. 1,

Fig. 3

einen Längsschnitt durch den Gegenstand nach Fig. 1 in vergrößerter Darstellung,

Fig. 4

einen Schnitt A-A durch den Gegenstand nach Fig. 3 und

Fig. 5

einen Ausschnitt aus dem Gegenstand nach Fig. 3 im Bereich einer Sprühdüse.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment. Show it

Fig. 1

a plant according to the invention for gluing fibers in a simplified schematic representation,

Fig. 2

an enlarged section of the object after Fig. 1 .

Fig. 3

a longitudinal section through the object Fig. 1 in an enlarged view,

Fig. 4

a section AA through the object after Fig. 3 and

Fig. 5

a section of the object after Fig. 3 in the area of a spray nozzle.

In the figures, a plant for gluing fibers 1 for the production of fiberboard, in particular MDF boards is shown. The system is set up for continuous operation and has a fiber feed device 2 with a fiber feed line 3 which can be charged with conveying air F for fiber transport and which opens into a fiber outlet tube 5 via an arcuate fiber deflection line 4. Further, a chute 6 is provided, which is downstream of the fiber outlet pipe 5. Between the fiber outlet pipe 5 and the chute 6 is a gluing device 7 with a plurality of spray nozzles 8 for spraying the emerging from the fiber outlet tube 5 and entering the chute 6 fibers 1 arranged with glue drops. In the exemplary embodiment, 16 spray nozzles are provided, which form a nozzle ring surrounding the fiber stream. The chute 6 is a collecting device 9 with a transport device 10 for collecting and optionally discharging the fibers 1 and a suction device 11 for sucking air from the chute 6 are arranged. The transport device 10 is an air-permeable conveyor belt, z. B. screen belt 10 is formed. The suction device 11 is arranged below the conveyor belt 10 so that it sucks the air out of the chute 6 through the conveyor belt 10. The fibers are for gluing means of conveying air F or transport air on the substantially vertically arranged straight fiber feed line 3 and the adjoining arcuate Faserumlenkleitung 4 and finally on the fiber outlet tube 5, which is also formed substantially perpendicular and straight, in the Beleimungsbereich between Fiber outlet pipe 5 and chute 6 blown. The glued by means of gluing device 7 fibers then fall through the chute 6 on the conveyor belt 10 and are discharged with this. The chute 6 has a downwardly widening cross section. Incidentally, it can be seen in the figures that a jacket air feed device 12 is provided below the glueing device 7, wherein this sleeve air feed device 12 generates a plurality of fan air ducts 13 for generating a fan air flow M surrounding the fiber flow in the chute. Consequently, by means of the suction device 11, both the conveying air F and the jacket air M as well as any ambient air U entering or entering the chute 6 are extracted.

In the Fig. 2 and 3 It can now be seen that the spray nozzles 8 according to the invention can be transferred from a waiting position into a working position for gluing the fibers and vice versa. Each spray nozzle is on one Pivoting lever 14 attached. With these pivoting levers 14, the spray nozzle 8 can be pivoted from the waiting position into the working position and swung out of the working position into the waiting position. In the Fig. 2 and 3 are the spray nozzles 8 with their pivot levers 14 in the working position. The waiting position is dash-dotted only indicated. Each spray nozzle 8 is individually attached to a separate pivot lever 14, wherein the individual pivot lever 14 individually or jointly and are swinging out. Further shows in particular Fig. 3 in that the pivoting levers 14 can be engaged and disengaged by means of swivel drives 15. These rotary actuators 15 are designed as pneumatic linear actuators, namely pneumatic cylinder piston assemblies, which are connected to the rotatably mounted pivot lever 14. In principle, rotary drives can be connected to the pivot lever 14. As a linear drives and a spindle drive or the like could be used. These embodiments are not shown in the figures.

Each pivot lever 14 has, on the one hand, a pivot arm 14a and, on the other hand, a pivot arm 14b. At the pivot arm 14a the spray nozzles 8 are connected end. The pneumatic cylinder piston arrangements are connected to the articulated arms 14b as drives 15, the pivoting levers 14 consequently having a substantially L-shaped form. The pneumatic linear drives 15 are hinged on the one hand to the pivot lever 14, namely to the pivot arm 14b and on the other hand to a suspension 16 on a frame or housing 17 pivotally. Furthermore, each spray nozzle 8 is associated with a collecting trough 18, which is arranged in the waiting position below the respective spray nozzle 8.

According to the invention, a control device, not shown, is provided, which is connected to the spray nozzles or the rotary actuators 15, wherein said control device swings the spray nozzles 8 in Beleimungsbetrieb from the waiting position to the working position and the interruption of the Beleimungsbetriebes automatically pivots from the working position to the waiting position. Furthermore, this control device can control the spray nozzles 8 themselves and consequently the glue outlet. It is provided that the control device pivots the spray nozzles 8 exclusively during the gluing operation in the working position. In this way, in particular contamination of the system is avoided, since possibly dripping glue outside the operating times can not penetrate into the chute 6, but is collected in the waiting position of the drip pans 18. For this purpose, it is expedient if in the area of the fiber jet, z. B. between the fiber outlet tube 5 and chute 6, a fiber sensor 19 is arranged, which z. B. may be formed as an optical sensor and generates a signal that depends on whether fibers 1 exit from the fiber outlet tube 5 or not. This fiber sensor 19 is also connected to the control device.

According to Fig. 5 the spray nozzles 8 are formed as two-fluid nozzles and to a glue supply line 20 and a first compressed air supply line 21 is connected, which supplies the atomizing air. According to the invention, the spray nozzles 8 also have a non-illustrated, movably guided cleaning pin with which the nozzle opening 23 of the spray nozzle can be cleaned or avoids soiling. To control this cleaning pin, a second compressed air line 22 is provided, which supplies control air for the cleaning pen.

Finally, the figures show that the shell air M is introduced via a throttle ring construction with adjustable throttle ring 24 and a shell air deflection in the chute. For this purpose, an inner shell ring 25 is disposed within the chute 6, which is connected to form a sharp edge K to a bottom plate or a bottom ring 26 of the gluing space. In this way, a strong turbulence of the shell air M is generated. This leads surprisingly in the chute 6 Particularly stable conditions and contamination of the chute walls are reliably avoided. Sharp edge means in the context of the invention in particular a non-rounded edge with an edge angle β between shell ring 25 and bottom ring 26 with β ≤ 120 °, preferably β ≤ 90 °.

Claims (12)

1. A plant for the glueing of fibres (1) for the manufacture of fibreboards, in particular MDF boards, or timber material boards of that kind, with a fibre feed unit (2) with at least one fibre feed conduit (3) to which feed air (F) can be supplied for purposes of transporting the fibres, which conduit leads via, e.g., a curved fibre deflecting conduit (4), into a fibre exit pipe (5),
   with a chute (6) arranged downstream of the fibre exit pipe (5),
   with a glueing device (7) with spray nozzles (8) for purposes of spraying the fibres exiting the fibre exit pipe (5) and entering the chute (6) with glue droplets, and
   with a collector device (9) arranged downstream of the chute (6) with a transporting device (10) for purposes of collecting and, as required, removal of the fibres, and a suction device (11) for purposes of sucking the air out of the chute through the transporting device,
   characterised in that,
   in the glueing operation the spray nozzles (8), or at least some of the spray nozzles (8), can be transferred out of a standby position into an operating position for purposes of glueing the fibres, and, in the event of an interruption of the glueing operation, can be transferred out of the operating position into the standby position.
2. The plant in accordance with Claim 1,
   characterised in that,
   the spray nozzles (8), or some of the spray nozzles (8), are attached to pivoting levers (14), and with these pivoting levers (14) can be pivoted out of the standby position into the operating position, and can be pivoted out of the operating position into the standby position.
3. The plant in accordance with Claim 2,
   characterised in that,
   each spray nozzle (8) is individually attached to a pivoting lever (14), wherein
   the individual pivoting levers (14) can be pivoted in and out of position individually or collectively, or in groups.
4. The plant in accordance with Claim 2 or 3,
   characterised in that,
   the pivoting levers (14) can be pivoted in and out of position with pivot drives (15).
5. The plant in accordance with Claim 4,
   characterised in that,
   the pivot drives (15) are designed as pneumatic or hydraulic drives, which are connected onto the pivoting levers (14), which are mounted such that they can rotate.
6. The plant in accordance with Claim 5,
   characterised in that,
   each of the pivoting levers (14) has at least one pivot arm (14a), on which the spray nozzles (8) are arranged, and at least one link arm (14b), to which the pivot drive (15) is connected.
7. The plant in accordance with one of the Claims 1 to 6,
   characterised in that,
   one or a plurality of collecting troughs (18) are assigned to the spray nozzles (8), which troughs in the standby position are arranged underneath the respective spray nozzle (8).
8. The plant in accordance with one of the Claims 1 to 7,
   characterised in that,
   the spray nozzles (8), are connected with a control device, which in the glueing operation pivots the spray nozzles (8) out of the standby position into the operating position, and in the event of an interruption of the glueing operation pivots them out of the operating position into the standby position.
9. The plant in accordance with Claim 8,
   characterised in that,
   at least one fibre sensor (19) recording the glueing operation is connected to the control device.
10. The plant in accordance with Claim 9,
    characterised in that,
    the fibre sensor (19) is designed as an optical sensor.
11. The plant in accordance with one of the Claims 1 to 10, wherein
    as two-substance nozzles, the spray nozzles (8) are connected to a glue feed line (20) and to a first compressed air line (21) for the atomisation air,
    characterised in that,
    the spray nozzles (8) have at least one flexibly guided cleaning pin (23), to which control air is supplied via a second compressed air line (22).
12. The plant in accordance with one of the Claims 1 to 11,
    characterised in that,
    the glueing device (7) is arranged between the fibre exit pipe (5) and the chute (6).

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