EP2248598A1 - Device with multiple dry air nozzles and method for discharging an adhesive - Google Patents

Abstract

The device (10) has nozzle openings (11.1-11.4) formed at or in housings (13.1-13.4) and an adhesive channel for supplying an adhesive to the nozzle openings is provided in the housing. A flow chamber is arranged in the region of the nozzle openings. The flow chamber is arranged in a gas supply (17). An outlet is provided in a region of the nozzle openings and arranged such that the adhesive and the gas are discharged through the outlet during supply of gas in to the flow chamber through the gas supply and during supply of the adhesive to the nozzle openings through the adhesive channel (12). An independent claim is also included for a method for discharging an adhesive bead- or adhesive sheet.

Description

The invention relates to devices having a plurality of nozzle openings and switchable adhesive feeds, which is operable in a first operating mode or a second operating mode, wherein in the first operating mode through all nozzle openings adhesive (eg in the form of adhesive beads) are discharged and in the second mode of operation only by a smaller Number of nozzle openings adhesive (eg in the form of adhesive beads) are discharged.

There is a co-pending European Patent Application entitled "Multiple High Pressure Nozzle and Protective Chamber Apparatus and Method for Dispensing an Adhesive" filed the same day as the present application.

In particular, the present invention relates to an apparatus for applying a flowable moisture-curing medium (eg, adhesive or sealant) on a workpiece. In particular, it is about the use of 1-component PUR adhesive.

Background of the Invention, Prior Art

In numerous industrial machining processes adhesives, sealants and similar flowable media are used, which are applied or sprayed onto a workpiece in liquid form.

For economic reasons, the devices for this must be suitable for different applications or workpieces of different sizes to be bonded or sealed.

In part, there are devices having a series of nozzles, for example, in a common comb-like arrangement. Some of these nozzles can be closed with a slider or piston to adjust the application width. This type of device has the advantage that only those nozzles are actuated, which are actually required due to the dimensions of the workpiece. The other nozzles remain closed.

Such devices have some drawbacks that occur especially when processing media that are moisture-curing. In addition to the high design overhead, leaks, dehydration and inaccurate or inefficient application of the flowable medium must be cited.

There are devices that are equipped with several nozzles in one housing. By a common slide or piston, a part of the nozzles can be separated from the supply of the medium. But here, too, the constructional overhead is relatively large.

One-component adhesives are known which cure once they come into contact with moisture. These adhesives are partially too referred to as moisture-curing cold glue or moisture-curing adhesive. As soon as these adhesives come in contact with moisture, the crosslinking process begins, which ultimately leads to the curing of the adhesive. Once the adhesive has cured, it can no longer be converted into the liquid form, as is the case with hot glue, for example.

• Sehr gute Adhäsionseigenschaften;
• Geringes Einlaufen/Schrumpfen des Klebstoffs;
• Beständig gegen Mineralöle;
• Klebstofffilm mit wesentlich höherer mechanischer Festigkeit als PUR Heissleim;
• Kälte- und wärmebeständiger als PUR Heissleim, sowie ausgezeichnete Flexibilität auch bei niedrigen Temperaturen;
• Besonders gut für Flächenverklebungen und Keilverzinkungen im Holzbau geeignet;
• Minimale Auftragstärke von 0,1 bis 0,2 mm und demzufolge geringerer Klebstoffverbrauch als bei Heissleim.

Polyurethane (PUR) single-component adhesive (1K-PUR), for example, is widely used because this adhesive offers many advantages over other hot melt adhesives, as exemplified below:

• Very good adhesion properties;
• Low shrinkage / shrinkage of the adhesive;
• Resistant to mineral oils;
• Adhesive film with much higher mechanical strength than PUR hotmelt;
• More resistant to cold and heat than PUR hotmelt, as well as excellent flexibility even at low temperatures;
• Particularly suitable for surface bonding and finger-jointing in timber construction;
• Minimal application thickness of 0.1 to 0.2 mm and consequently lower adhesive consumption than hot glue.

Unfortunately, however, such moisture-curing adhesives are difficult to handle. Particularly critical is the cleaning of valves, nozzles and tools as the adhesive begins to harden after it has absorbed moisture.

Often, membrane-based application systems are used to deliver or apply such moisture-curing adhesives, as the diaphragm valves provide good sealing between the adhesive and the air. However, the membrane-based application systems have a number of disadvantages. Among other things, the diaphragm valves tolerate no pressures that are above 20 bar. In addition, the life is (calculated in number of valve lifts) relatively low and the diaphragm valves are expensive.

Especially when processing moisture-curing media has been shown that it comes with an individual or group-wise shutdown of individual nozzles for premature curing of the medium. As a result, supply lines, the nozzle mechanism or the nozzle openings are dirty or even completely blocked. Depending on the medium that was used, the cleaning effort can be enormous. During such cleaning, the device is necessarily out of service, which has an impact on the economy. In the mentioned membrane-based application systems, the frequent change of the diaphragm valves is added.

However, there has long been a need to provide application systems for moisture-curing media that allow a nozzle to material distance greater than 20 mm. In addition, the medium should enter into an intimate connection with the material as possible after dispensing on the material.

Against this background, the object was to provide a device for applying a flowable medium, which is adaptively adaptable to different large workpieces or job conditions and largely avoids the mentioned disadvantages of premature curing or soiling.

In addition, the object is to provide a device for applying a flowable medium, which allow working with a large distance between the nozzle and the material and which makes it possible that the medium forms an intimate connection with the material.

In addition, the task is to create a corresponding method.

The object is achieved by a device according to claim 1 and by a method according to claim 9.

A first device according to the invention is equipped with a plurality of nozzle openings and switchable adhesive feeders, each nozzle of the apparatus having a needle or piston valve (preferably electromagnetically driven). The apparatus may be operated in a first mode of operation and in a second mode of operation, wherein in the first mode of operation adhesive (e.g., in the form of adhesive beads) is dispensed through all nozzle openings. In contrast, in the second mode of operation, glue (e.g., in the form of adhesive beads) is dispensed only through a smaller number of the nozzle orifices. Each nozzle opening is formed on or in a housing in which an adhesive channel for supplying the adhesive to the nozzle opening is present. In addition, the housing comprises a flow chamber in the region of the nozzle opening and a gas supply, which is connected to the flow chamber. The device has an outlet opening in the region of the nozzle opening, which is arranged so that upon supply of gas through the gas supply into the flow chamber and the supply of adhesive through the adhesive channel to the nozzle opening, through the outlet opening simultaneously adhesive and gas is discharged.

The gas stream that exits with the adhesive has two main functions. On the one hand, the gas stream prevents the settling or depositing of adhesive residues at the nozzle opening or in its surroundings. On the other hand, the gas stream provides a gas jacket, which prevents the curing of the adhesive in the region of the nozzle opening. As a result, it is possible to realize devices whose nozzle openings can be switched on or off as required without premature drying or curing of the adhesive.

The invention is particularly suitable for moisture-curing (moisture-curing) adhesives. In this case, a dry gas (eg, a dried air stream) is used to coat the adhesive as it leaves the nozzle orifice. If a nozzle is in In an operating mode is not used, so gas continues to flow through the outlet opening of this nozzle to protect the nozzle or its environment from hardening of the adhesive even when switched off.

This embodiment is particularly advantageous, since the device can be configured as required by switching individual nozzles on or off, without premature curing of the adhesive taking place.

Polyurethane adhesive (PUR) has been used as a special adhesive for some time. PUR has the disadvantage that moisture, e.g. Ambient moisture that causes crosslinking or curing. This leads to various problems. An example is the great cleaning effort of the components of the device. PUR adhesives are also problematic because toxic fumes can form during processing. These vapors can cause, for example, respiratory or skin diseases. For this reason, certain maximum workplace concentrations (MAK value) must be adhered to. By providing a gas jacket at the exit of the adhesive beads is also provided for protection against the vapors. The protective effect can be improved by using a suction device in the area of the device to absorb the gas and the vapors.

• Generell bringt eine erfindungsgemäße (Auftrage-)Vorrichtung folgende Vorteile:
• die Düsen sind je nach Abmessungen des Werkstücks variabel ansteuerbar.
• Es können auch punktuelle Applikationen des fließfähigen Mediums realisiert werden.
• Düsen, die sich nicht im Einsatz befinden, trocknen nicht aus und verstopfen nicht.
• Mit entsprechenden Sensorsteuerungen ist eine laufende Adaption an unterschiedlich große Werkstücke realisierbar.Es können hohe Drücke oberhalb von 30 bar, vorzugsweise in einem Bereich zwischen 35 bar und 100 bar, erreicht werden. Die Selbstdichtheit der einzelnen Hochdruckdüsen mit Nadel- oder Kolbenventil liegt entsprechend oberhalb von 30 bar.
• Es können Distanzen zwischen Düse und Material M erzielt werden, die grösser sind als 20mm.
• Es können Strahlgeschwindigkeiten des abgegebenen Mediums erreicht werden, die größer sind als 4 m/s und die vorzugsweise zwischen 4 m/s und 12 m/s liegen.
• Durch den Einsatz der Strömungskammer im Bereich der Düsenöffnung ist keine austrittsseitige Reinigung mehr erforderlich.
• Falls die Vorrichtung mit einer Schutzkammer und einem Schutzmedium ausgestattet ist, reduziert sich auch dadurch der Wartungsaufwand deutlich.

In a particularly preferred embodiment, needle or piston valves are used in the device, which can be operated at pressures above 30 bar, preferably in a range between 35 bar and 100 bar. According to the invention, so-called high-pressure nozzles with needle or piston valve are used. Such devices have, unlike the membrane-based application systems mentioned above, the advantage that they reach a jet velocity of the discharged medium which is greater than 4 m / s and which is preferably between 4 m / s and 12 m / s.

• In general, an applicator device according to the invention has the following advantages:
• the nozzles are variably controllable depending on the dimensions of the workpiece.
• It can also be realized point applications of the flowable medium.
• No-use jets will not dry out or clog.
• With appropriate sensor controls a continuous adaptation to different sized workpieces is feasible. It can high pressures above 30 bar, preferably in a range between 35 bar and 100 bar, can be achieved. The self-tightness of the individual high-pressure nozzles with needle or piston valve is correspondingly above 30 bar.
• It can be achieved distances between nozzle and material M, which are greater than 20mm.
• It can jet velocities of the discharged medium can be achieved, which are greater than 4 m / s and which are preferably between 4 m / s and 12 m / s.
• The use of the flow chamber in the region of the nozzle opening means that no cleaning on the outlet side is required.
• If the device is equipped with a protective chamber and a protective medium, thereby also reduces the maintenance significantly.

In the subclaims further advantageous embodiments of the invention are listed.

pictures

Fig. 1

eine schematische Perspektivansicht einer ersten Ausführungsform der Erfindung;

Fig. 2A-2C

schematische Draufsichten einer weiteren Ausführungsform der Erfindung in verschiedenen Betriebszuständen;

Fig. 3

einen Schnitt durch einen Teil einer weiteren Ausführungsform der Erfindung;

Fig. 4

eine Ansicht eines Teils einer weiteren Ausführungsform der Erfindung;

Fig. 5

einen Schnitt durch einen Teil einer weiteren Ausführungsform der Erfindung;

Fig. 6

einen Schnitt durch einen Teil einer weiteren Ausführungsform der Erfindung.

In the following, further details and advantages of the invention will be described in detail by means of embodiments and partly with reference to the drawing. All figures are schematic and not to scale, and corresponding structural elements are given the same reference numerals in the different figures, even if they are designed differently in detail. Show it:

Fig. 1

a schematic perspective view of a first embodiment of the invention;

Fig. 2A-2C

schematic plan views of another embodiment of the invention in different operating conditions;

Fig. 3

a section through a part of another embodiment of the invention;

Fig. 4

a view of a part of another embodiment of the invention;

Fig. 5

a section through a part of another embodiment of the invention;

Fig. 6

a section through a part of another embodiment of the invention.

Detailed description of the embodiments

The principle of the invention will be described below with reference to a first embodiment. In Fig. 1 is a device 10 with a plurality of nozzle openings 11.1 - 11.4 arranged in a row and with switchable adhesive feed lines 12. This device 10 is operable in a first operating mode or a second operating mode. In the first operating mode, the Fig. 1 is shown through all the nozzle openings 11.1 - 11.4 through adhesive (here adhesive beads) KR delivered. In the second mode of operation, only a smaller number of the nozzle openings (eg only the nozzle openings 11.1 and 11.2, as in FIG Fig. 2B shown) adhesive (here adhesive beads) KR delivered.

Each of the nozzle openings 11.1 - 11.4 is formed on or in a housing 13.1 - 13.4. The housing / s 13.1 - 13.4 have an adhesive channel 15 (see, eg Fig. 3 ) for supplying the adhesive K to the nozzle opening 11.1 - 11.4. In Fig. 1 is indicated that the adhesive K is supplied via hoses or tubes 12 to the adhesive channel 15 or the adhesive channels 15. In addition, according to the invention in or on the housing 13.1 - 13.4 a flow chamber 16 in the immediate region of the nozzle opening 11.1 - 11.4 arranged. Details are the Fig. 3 refer to. It is Furthermore, a gas supply 17 is connected to the flow chamber 16. In Fig. 1 this gas supply 17 is indicated schematically by a thin line. In practice, this gas supply 17 has a larger diameter because of the required gas flow, or it is per nozzle opening 11.1 - 11.4 own gas supply 17 available.

The device 10 each comprises an outlet opening 14.1 - 14.4 (see, for example Fig. 3 ) in the region of each of the nozzle openings 11.1 - 11.4. The outlet openings 14.1 - 14.4 are arranged so that when supplying gas G through the gas supply 17 into the flow chamber 16 and the supply of adhesive K through the adhesive channel 12 to the nozzle opening 11.1 - 11.4 through the outlet opening 14.1 - 14.4 at the same time adhesive KR and gas G are deliverable. The exiting gas G and the outlet openings 14.1 - 14.4 are in Fig. 1 not recognizable.

Fig. 1 shows the following exemplary further details. In the example shown, a plurality of adhesive beads KR are dispensed parallel to one another onto a material M (also called a material) with the device 10. It is provided for this purpose, a relative movement V between the device 10 and the material M.

In Fig. 1 It can be seen that one housing or housing part 13.n can be provided per nozzle opening 11.n. But it is also conceivable that all nozzle openings are housed 11.n in a common housing. If a housing or housing part 13.n is provided per nozzle opening 11.n, then an adhesive feed 12 and / or a gas feed 17 is preferably also provided per nozzle opening 11.n.

According to the invention, the individual flow chamber 16 and the outlet openings 14.1-14.4 are arranged with respect to the respective nozzle openings 11.1-11.4 so that the gas G forms a gas jacket around the adhesive KR. This principle is in Fig. 3 indicated schematically, where it is shown that a leaking adhesive bead KR is surrounded by a slightly conical gas jacket G.

The device 10 is designed in such a way that all the nozzle openings 11.1 - 11.4 can always be supplied with the gas G through the gas supply 17 both in the first operating mode and in the second operating mode. For this purpose, a sufficiently powerful gas source 20 must be used, which is able to permanently provide a gas volume flow of sufficient size. Preferably, the device 10 operates with a pressure tank 21 as a buffer between the gas source 20 and the flow chambers 16. The pressure tank 21 is optional.

In Fig. 2A another device 10 of the invention is shown in a schematic plan view. The device also comprises four nozzle openings 11.1 - 11.4 arranged in a row here. That is to say, the nozzle openings 11.1 - 11.4 sit along a common line L. The nozzle openings 11.1 - 11.4 can, however, also be grouped in a different arrangement (eg staggered relative to one another). In the Fig. 2A shown device 10 is operated in the moment shown in the first mode of operation. In this mode, adhesive beads KR are delivered through all the nozzle openings 11.1-11.4. This results in a first application width transverse to the movement V of the material M, which is designated here by B1.

In Fig. 2B the same device 10 of the invention is shown in a schematic plan view. In the Fig. 2B shown device 10 is operated in the moment shown in the second mode of operation. In this mode, less than four nozzle openings 11.1 - 11.4 (here the nozzle openings 11.1 and 11.2) are supplied with adhesive K. Therefore, only two adhesive beads KR are produced. This results in a second application width transverse to the movement V of the material M, which is designated here by BB. B2 is smaller than B1.

In Fig. 2C the same device 10 of the invention is shown in a schematic plan view. In the Fig. 2C shown device 10 is operated in the moment shown in a third mode of operation. In this mode, less than four nozzle openings 11.1 - 11.4 (here the nozzle openings 11.1, 11.2 and 11.4) are supplied with adhesive K. Therefore, only three adhesive beads KR are produced in this example. This results in an order width transverse to the movement V of the material M, which corresponds to the application width B1, but the distance between two of the adhesive beads KR is greater.

Fig. 3 shows a section through a part of a further embodiment of the invention. It is the section through a housing 13.1 shown with a nozzle opening 11.1. The adhesive K is guided from the right through an adhesive channel 15 into a nozzle chamber 18 of the housing 13.1. In this nozzle chamber, a nozzle needle 19 can be moved up and down to open or close the nozzle opening 11.1. In the example shown, the individual flow chamber 16 surrounds a lower portion of the nozzle 24 at 360 degrees. That is, the flow chamber 16 is arranged rotationally symmetrically around the nozzle 24 around. This can be achieved by placing or attaching a cap-like housing 22 to the lower region of the nozzle 24. In order to be able to connect the housing 22 tightly to the nozzle 24, a sealing ring 23 may be arranged in the upper area, as in FIG Fig. 3 indicated. Laterally (here from the right), the gas stream G is blown through a gas supply 17 into the flow chamber 16. The gas stream G circulates around the nozzles 24 as it enters the flow chamber 16, where it leads to a cooling effect if cold gas G is introduced. If you want to prevent premature cooling, the gas G is preheated.

Fig. 4 shows a view of a part of another embodiment of the invention. It is a view of a housing 13.n shown with a nozzle 24 with nozzle opening 11.n. The nozzle 24 and the nozzle opening 11.n are shown in dashed lines, since they are surrounded by a cap-like housing 22 having a sealing ring 23 or a rubber-like sealing collar at the top.

The gas flow G is injected at such a pressure in the flow chamber 16 that there is an overpressure. As a result of this overpressure, gas G, together with the adhesive KR, exits downwards through an outlet opening 14.1. The gas G encases the adhesive bead KR as indicated.

Preferably, the housing 22 is designed so that the outlet opening 14.1 is formed in the housing 22. However, the outlet opening 14.1 can also be provided on the housing 13.1 of the nozzle 24.

Preferably, each nozzle opening 11.n is individually switchable, which can be achieved, for example, with an electromagnetically movable nozzle needle 19 in a nozzle chamber 18.

Preferably, a cap-like housing 22 made of a plastic material or rubber material is used, which can be inserted by hand over the nozzles and replaced if necessary.

Preferred is an embodiment of the cap-like housing 22, which is suitable for retrofitting existing devices 10. In this case, the cap-like housing 22 may have a side gas port 17 for connection to a gas source 20, as in FIG Fig. 4 shown.

The adhesive supply and / or the gas supply can be completely controlled by a controller 30 (clocked switched on and off). The controller 30 is in Fig. 1 indicated schematically.

A device 10 according to the invention can be equipped with various control and control elements in order to be able to monitor the method according to the invention. These control and control members may e.g. be controlled by the controller 30.

The mentioned gas source 20 and / or the pressure tank 21 is / are preferably provided in the various embodiments with a sensor 32 which, like a hygrometer, measures the moisture content of the air. The dried gas (preferably in the form of dried air) preferably has a relative humidity in a range of 0-0.5%, preferably 0.45%.

Particularly preferred is one of the previously described devices 10, but which is designed so that the gas stream G, from the Outlet opening 14.n outlet has a dew point (or dew point) of 40 ° C atm.

Preferably, in the various embodiments, the gas source 20 and / or the pressure tank 21 are designed so that exits per nozzle opening 11.n between 1 and 1.5 standard liters of gas per minute through the outlet opening 14.n. Per day and nozzle opening 11.n you need about 40 m ^{3 of} dry gas. By providing the individual flow chambers per nozzle, the consumption of dry gas can be kept relatively small.

In a device 10 with twenty nozzle openings 11.1 - 11.20, the gas source 20 must thus be able to produce about 20 to 30 standard liters of gas per minute.

In one of the previously described particularly preferred embodiments, the nozzle orifices 11.n, which are not needed, are immersed in a liquid bath containing a liquid which prevents the adhesive from curing. In this case, no gas G must be supplied to the respective nozzles 24 as soon as the nozzles 24 are immersed in the liquid.

Preferably, a compressed air refrigerant dryer or an adsorption dryer is used as the gas source 20. Also suitable as gas source 20 are membrane or disk dryers.

The use of a gas flow, as mentioned, has the advantage that also no dirt particles (for example paper abrasion) can adhere to the nozzles 24.

In one of the previously described particularly preferred embodiment, the device 10 in addition to the flow chamber 16 per nozzle on a protective chamber 40 with a protective medium SM. The protective chamber 40 is arranged in the rear region of the needle or piston valve so that the needle or the piston 19 of the valve penetrates the protective chamber 40. The protection chamber 40 together with the protective medium SM, the is statically in the protection chamber 40 (see Fig. 5 ) or the protective chamber 40 (dynamic) flows through (see Fig. 6 ), form a barrier against air. It has been shown that in high-pressure valves, which are operated at pressures above 30 bar and have to complete a large number of strokes, small amounts of adhesive K can escape backwards along the needle or the piston 19. This adhesive K hardens or clogs. Without special countermeasures valve seals are damaged, which means that often manual intervention for the maintenance of the device 10 would have to be made.

In Fig. 5 FIG. 2 shows the example of an embodiment of a device 10 equipped with a protective chamber 40 containing the protective medium SM (here a liquid). The needle or the piston 19 of the valve has at its output end here a spherical shape 44. However, it may also have a different shape. At the rear end of the needle or piston 19, it penetrates a chamber 40, as shown. The needle or piston 19 is enclosed by sealing elements (eg, sealing rings) to prevent or reduce the backward leakage of adhesive K. Preferably, seals 41, 42 are disposed immediately below and above the protection chamber 40. Laterally, a channel 43 or a reservoir for the protective medium SM is provided, as in Fig. 5 to recognize. Should during an up and down movement (in Fig. 5 represented by the double arrow P1) of the needle or the piston 19 adhesive from the region 18 to the rear, this adhesive residue is absorbed in the protective chamber 40 from the protective medium SM. During the up and down movement P1 opens and closes the valve, since the ball 44 comes in a lower position in a valve seat 45 for tight fitting.

In Fig. 6 the example of an embodiment of a device 10 is shown, which is equipped with a protective chamber 40, in which the protective medium SM (here a liquid) is introduced via a feed channel 43.1 and removed via a discharge channel 43.2. The needle or the piston 19 of the valve has a slightly pointed shape at its output end here. But it can also have a different shape. At the rear end of the needle or the piston 19, this penetrates one Chamber 40, as shown. The needle or piston 19 is enclosed by sealing elements (eg, sealing rings) to prevent or reduce the backward leakage of adhesive K. Preferably, seals 41, 42 are disposed immediately below and above the protection chamber 40. Laterally, a reservoir may be provided for the protective medium SM, which in Fig. 6 can not be seen. Should during an up and down movement (in Fig. 6 represented by the double arrow P1) of the needle or the piston 19 adhesive K from the area 18 to the rear, this adhesive residue is absorbed in the protective chamber 40 from the protective medium SM. During the up and down movement P1, the valve opens and closes, as the needle or plunger tip comes in a lower position in a valve seat to dense concern.

Particularly preferred is an embodiment in which a liquid is used as the protective medium SM. Particularly suitable is a solvent liquid which serves as a solvent for the adhesive K, which is processed in the device 10. If smaller adhesive residues should escape to the rear, these residues in the protective chamber 40 are virtually dissolved by the solvent. There is therefore no lumping and damage to the seal (s). Ruetasolv (from RKS GmbH, Germany) has proven to be particularly suitable as a solvent for 1-K PUR adhesive, since this solvent is also used as a softener in this adhesive.

Particularly preferred is an embodiment in which the protective medium SM is moved in the protective chamber 40, that is, is conveyed, as by means of an exemplary embodiment in FIG Fig. 6 shown. For this purpose, a small pumping system, which keeps the protective medium SM in motion so that never a supersaturation of the protective medium SM can occur with adhesive residues.

The solutions that are equipped with the protection chamber 40 and the protective medium SM, show a much lower maintenance requirements, since both the wear of valve seals as well as the contamination or blockage can be prevented or reduced by adhesive residues.

The described devices 10 have a long service life and can easily complete significantly more than 100,000 strokes of the nozzle valves without maintenance. It can even be reached 1'000'000 strokes.

The present invention is particularly suitable for use in the wood industry, where, for example, load bearing roof beams with high reliability.

Preferably, distances L between the nozzle and material M which are larger than 20 mm and preferably up to 50 mm can be made possible. However, the solution according to the invention can also be used in the "near range" e.g. between 2 and 5 mm distance.

The invention enables a precise and intimate wetting of the material M, since the adhesive K is discharged at a high exit speed. The measures described, the maintenance costs compared to conventional devices is significantly lower.

Claims (13)

Device (10) with a plurality of nozzle openings (11.1-11.4) and switchable adhesive feeds (12, 15) which can be operated in a first operating mode or a second operating mode, wherein in the first operating mode through all nozzle openings (11.1-11.4) adhesive (KR) is discharged and in the second mode of operation only by a smaller number of the nozzle openings (11.1 - 11.2) adhesive (KR) is discharged, wherein: - Each nozzle opening (11.1 - 11.4) on or in a housing (13.1 - 13.4) is formed in which an adhesive channel (15) for supplying the adhesive (K) to the nozzle opening (11.1 - 11.4) is present, - A flow chamber (16) in the region of the nozzle opening (11.1 - 11.4) is arranged, a gas supply (17) is connected to the flow chamber (16), - The device (10) has an outlet opening (14.1 - 14.4) in the region of the nozzle opening (11.1 - 11.4), which is arranged so that when supplying gas (G) through the gas supply (17) in the flow chamber (16) and when supplying adhesive (K) through the adhesive channel (12) to the nozzle opening (11.1 - 11.4), adhesive (KR) and gas (G) at the same time through the outlet opening (14.1 - 14.4) can be dispensed through. Device (10) according to claim 1, characterized in that the flow chamber (16) and the outlet opening (14.1-14.4) are arranged with respect to the nozzle opening (11.1-11.4) such that the gas (G) forms a gas jacket around the adhesive ( KR) around. Device (10) according to claim 1 or 2, characterized in that all the nozzle openings (11.1 - 11.4) both in the first operating mode and in the second operating mode always by the gas supply (17) through the gas (G) can be supplied. Device (10) according to claim 1 or 2, characterized in that it comprises a gas source (20) which is designed during the operation of the Device (10) to permanently provide and supply a gas volume, so that all the nozzle openings (11.1 - 11.4) in both the first operating mode and in the second operating mode always by the gas supply (17) through the gas (G) can be supplied. Device (10) according to one of the preceding claims, characterized in that the flow chamber (16) is formed by a cap-like housing (22). Device (10) according to any one of the preceding claims, characterized in that it comprises per nozzle opening (11.1 - 11.4) a high-pressure needle or piston valve. Device (10) according to claim 6, characterized in that it comprises a protective chamber (40) in the rear region of the needle or piston valve, which sealingly surrounds a needle or a piston (19) of the needle or piston valve. Device (10) according to claim 7, characterized in that the protective chamber (40) is filled or filled with a liquid or with dry air as a protective medium (SM). Method for dispensing a plurality of parallel adhesive beads or webs (KR) through a plurality of nozzle openings (11.1-11.4) onto a material (M), comprising the following steps: Providing dry gas (G), Introducing the dry gas (G) into individual flow chambers (16) arranged in the region of each nozzle opening (11.1-11.4), Selecting a first operating mode or a second operating mode, wherein in the first operating mode adhesive (KR) is dispensed through all nozzle openings (11.1-11.4) and in the second operating mode adhesive (KR) only by a smaller number of nozzle openings (11.1-11.2) is dispensed - Incorporation of adhesive (K) in individually switched on and off Nozzle chambers (18), wherein
o the adhesive (K) in the form of adhesive beads or webs (KR) exits through those nozzle openings (11.1 - 11.4), which are switched on by selecting the operating mode,
o the dry gas (G) forms a gas jacket around the adhesive beads or webs (KR), and
o whereby also from the shut off nozzle openings (11.1 - 11.4) dry gas (G) flows out. A method according to claim 9, characterized in that a part or all nozzle openings (11.1 - 11.4) are immersed in a liquid, if a part or all the nozzle openings (11.1 - 11.4) are not in operation. A method according to claim 10, characterized in that a gas source (20) per nozzle opening (11.n) provides between 1 and 1.5 standard liters of gas per minute. Method according to one of claims 9, 10 or 11, characterized in that the adhesive beads or webs (KR) after emerging from the nozzle openings (11.1 - 11.4) have a jet velocity which is greater than 4 m / s and preferably between 4 m / s and 12 m / s. A method according to claim 9, characterized in that high-pressure needle or piston valves are used, which are operated with an internal pressure above 30 bar, preferably in a range between 35 bar and 100 bar.

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