WO2010128019A1

WO2010128019A1 - Device comprising several dry air nozzles and method for dispensing an adhesive

Info

Publication number: WO2010128019A1
Application number: PCT/EP2010/055989
Authority: WO
Inventors: Beatus Michael Ineichen
Original assignee: Robatech Ag
Priority date: 2009-05-07
Filing date: 2010-05-03
Publication date: 2010-11-11
Also published as: EP2248598A1; EP2248598B2; EP2248598B1

Abstract

The invention relates to a method and a device for dispensing a moisture-curing adhesive (K). The device (10) comprises several nozzle openings (11.1 - 11.4) and switchable adhesive supply lines (12). The device (10) can be operated in two operating modes, wherein, in the first operating mode, adhesive (K) is dispensed through all nozzle openings (11.1 - 11.4) and, in the second operating mode, adhesive (K) is dispensed only through a smaller number of nozzle openings (11.1 - 11.2). Each nozzle opening (11.1 - 11.4) is formed at or in a housing (13.1 - 13.4) which comprises an adhesive duct (15) for supplying the adhesive (K) to the nozzle opening (11.1 - 11.4). For each nozzle opening (11.1 - 11.4), there is one flow chamber (16) disposed in the area of the nozzle opening (11.1 - 11.4). A gas supply (17) is connected to the flow chambers (16). The device (10) comprises outlet openings (14.1 - 14.4) in the area of the nozzle opening (11.1 - 11.4), which are arranged in such a manner that adhesive (K) and gas (G) can be dispensed simultaneously through the outlet opening (14.1 - 14.4) during operation.

Description

Device with several dry air nozzles and method for dispensing an adhesive

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 the nozzle openings adhesive (eg in the form of adhesive beads) are discharged and in the second operating mode only be given by a smaller number of nozzle openings adhesive (eg in the form of adhesive beads).

It becomes the priority of the European patent application EP 09 159

657.7 entitled "Apparatus with Multiple Dry-Air Nozzles and Method for Dispensing an Adhesive" filed on 7.5.2009 with the European Patent Office.

There is a parallel European priority

Patent application entitled "Device with several high-pressure nozzles and protective chambers and method for dispensing an adhesive", which is on the same Day was filed as the European patent application EP 09 159 657.7. There is also an international subsequent application filed on the same day as the present international subsequent application for this parallel priority European patent application.

The present invention particularly relates to a device for

Applying a flowable moisture-curing medium (e.g., adhesive or sealant) to a workpiece. In particular, it is about the use of 1-component PUR adhesive.

Background of the Invention, Prior Art

[005] In many industrial machining processes come

Adhesives, sealants and similar flowable media are used, which are applied or sprayed onto a workpiece in liquid form.

The devices for this must be suitable for different applications or different sized to be bonded or sealed workpieces for economic reasons.

In part, there are devices which have a number 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 disadvantages that occur especially when media are processed 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 a plurality of nozzles in a 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.

There are known one-component adhesives that cure as soon as they come in contact with moisture. These adhesives are sometimes 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.

Polyurethane (PUR) one-component adhesive (IK-PUR), for example, is frequently used, since this adhesive offers numerous advantages compared to 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;

- Minimum 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. Frequently, membrane-based application systems are used to deliver such moisture-curing adhesives, respectively, to apply, since the diaphragm valves provide a good seal 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 (calculated in number of valve strokes) is relatively low and the diaphragm valves are expensive.

Especially in the processing of 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 distance between the nozzle and material that is 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 task was to provide a device for applying a flowable medium, which is adaptively adaptable to different large workpieces or job conditions and avoids the mentioned disadvantages of premature curing or soiling as far as possible.

In addition, the task is an apparatus for applying a flowable medium to create, working with a large Allow distance between nozzle and material and makes it possible that the medium forms an intimate connection with the material.

In addition, the task is to provide 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 device 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 exiting with the adhesive has two major 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. This makes it 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 (e.g., a dried air stream) is used to coat the adhesive as it leaves the nozzle orifice. If a nozzle is not needed in an operating mode, gas continues to flow through the outlet opening of this nozzle in order to protect the nozzle or its surroundings from curing of the adhesive, even when switched off. This embodiment is particularly advantageous because the device can be configured as required by the connection or disconnection of individual nozzles, without causing the premature curing of the adhesive.

Polyurethane adhesive (PUR) has been used as a special grade of 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.

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 at the beginning, the advantage of 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 controlled 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 can be realized. 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.

- By using the flow chamber in the region of the nozzle opening, no exit-side cleaning 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 In the following, further details and advantages of the invention will be described in detail by means of embodiments and in part 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 is a schematic perspective view of a first

Embodiment of the invention; 2A-2C are schematic plan views of another embodiment of the

Invention in different operating conditions; 3 shows a section through part of a further embodiment of the invention; Fig. 4 is a view of a part of another embodiment of the

Invention; 5 shows a section through part of a further embodiment of the invention; Fig. 6 is a section through a part of another embodiment of the invention.

Detailed description of the embodiments

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

Each of the nozzle openings 11.1 - 11.4 is on or in a housing 13.1 - 13.4 trained. 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 it 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 on this are shown in FIG. 3. Furthermore, a gas supply 17 is connected to the flow chamber 16. In Fig. 1, this gas supply 17 is schematically indicated 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 apparatus 10 each comprise 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 escaping gas G and the outlet openings 14.1 - 14.4 can not be seen in Fig. 1.

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 per nozzle opening 11. n a housing or housing part 13. n can be provided. However, it is also conceivable that all nozzle openings 11. 11 are accommodated in a common housing. If a housing or housing part 13. N is provided per nozzle opening 11. 1, an adhesive feed 12 and / or a gas feed 17 is preferably also provided per nozzle opening 11. According to the invention, the individual flow chamber 16 and the outlet opening 14.1 - 14.4 arranged in relation to the respective nozzle opening 11.1 - 11.4 that the gas G forms a gas jacket around the adhesive KR around. This principle is indicated schematically in FIG. 3, where it is shown that an emerging adhesive bead KR is surrounded by a slightly conical gas jacket G.

The device 10 is designed so that all the nozzle openings 11.1 - 11.4 are always supplied through the gas supply 17 with the gas G 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 the nozzle openings 11.1-11.4 are seated along a common line L. The nozzle openings 11.1-11.4 may, however, also be grouped in a different arrangement (e.g., offset from one another). The device 10 shown in FIG. 2A is operated in the moment shown in the first operating mode. 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 Bl.

In Fig. 2B, the same device 10 of the invention is shown in a schematic plan view. The device 10 shown in Fig. 2B 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 Bl. In Fig. 2C, the same device 10 of the invention is shown in a schematic plan view. The device 10 shown in Fig. 2C 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 application width transverse to the movement V of the material M, which corresponds to the application width Bl, but the distance between two of the adhesive beads KR is greater.

Fig. 3 shows a section through 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 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 connect the housing 22 tightly with the nozzle 24, a sealing ring 23 may be arranged in the upper region, as indicated in Fig. 3. 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 caterpillar 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 that 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 shown in FIG. 4.

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 indicated schematically in FIG.

A device 10 according to the invention may be equipped with various control and control members to monitor the inventive method can. 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 with a sensor 32 in the various embodiments, 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, which, however, is designed so that the gas stream G exiting from the outlet opening 14. n has a dew point (or dew point) of 40 ⁰ 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 particularly preferred embodiments described above, 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 no dirt particles (eg paper abrasion) can settle on 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, which is statically located in the protection chamber 40 (see FIG. 5) or which flows through the protection chamber 40 (dynamically) (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, the example of an embodiment of a device 10 is shown, which is 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 can be seen in FIG. If during an up and down movement (shown in FIG. 5 by the double arrow Pl) of the needle or of the piston 19, adhesive from the area 18 penetrates to the rear, this adhesive residue is absorbed by the protective medium SM in the protective chamber 40. In the up and down movement Pl 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 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 provided for the protective medium SM, a reservoir, which is not visible in Fig. 6. If, during an up and down movement (represented by the double arrow P1 in FIG. 6) of the needle or of the piston 19, adhesive K from the region 18 penetrates to the rear, this adhesive residue is absorbed by the protective medium SM in the protective chamber 40. In the up and down movement Pl opens and closes the valve, since 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 moves in the protective chamber 40, that is, is conveyed, as shown in an exemplary embodiment in Fig. 6. 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 occur with adhesive residues can.

The solutions that are equipped with the protective 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 100'0OO strokes of the nozzle valves without maintenance. It can even be reached l'000'OOO strokes. The present invention is particularly suitable for use in the wood industry, where, for example, supporting roof beams are to be bonded with high reliability.

Preferably, distances L between nozzle and material M can be made possible, which are larger than 20 mm and preferably can be up to 50 mm. However, the solution according to the invention can also be used in the "near range", for example 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 outlet speed. The measures described, the maintenance costs compared to conventional devices is significantly lower.

Claims

claims:

1. Device (10) having 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.

2. 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) that the gas (G) a gas jacket around the Forming adhesive (KR) around.

3. Device (10) according to claim 1 or 2, characterized in that all 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.

4. Device (10) according to claim 1 or 2, characterized in that it comprises a gas source (20) which is designed during the operation of 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.

5. Device (10) according to any one of the preceding claims, characterized in that the flow chamber (16) by a cap-like housing (22) is formed.

6. 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.

7. 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.

8. 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).

9. A method for dispensing a plurality of parallel adhesive beads or webs (KR) through a plurality of nozzle openings (11.1-11.4) on 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) through those nozzle openings (11.1 - 11.4) emerges through

Selection of the operating mode are turned on, o the dry gas (G) around the adhesive beads or webs (KR) around forms a gas jacket, and o wherein also from the shut-off nozzle openings (11.1 - 11.4) dry gas (G) flows out.

10. The method according to claim 9, characterized in that a part or all the nozzle openings (11.1 - 11.4) are immersed in a liquid, if a part or all nozzle openings (11.1 - 11.4) are not in operation.

11. The 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.

12. The method according to any one of claims 9, 10 or 11, characterized in that the adhesive beads - or webs (KR) after exiting the nozzle openings (11.1 - 11.4) have a jet velocity which is greater than 4 m / s and the preferably between 4 m / s and 12 m / s.

13. The 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.