Wide pattern nozzle

Abstract

The invention relates, inter alia, to a device (10) for applying a plurality of threads (17) of a fluid, such as adhesive or lotion, to a moving web-like substrate (11), having a plurality of outlet openings (15a, 15b, 15c, 15d, 15e) for the threads of fluid (17, 17a, 17b, 17c), wherein each outlet opening is disposed between a pair of flow openings (16a, 16b, 16c, 16d, 16e), through which a flow fluid (21), in particular compressed air, flows in order to achieve thread oscillation. The special feature consists, inter alia, in that the outlet openings are disposed along a curved path (22, 22).

Claims

1. A device for applying a plurality of threads of a fluid to a moving web-like substrate, having a plurality of outlet openings for the threads of fluid, wherein each outlet opening is disposed between a pair of flow openings, through which a flow fluid flows in order to achieve thread oscillation, characterized in that the outlet openings and the flow openings are disposed along a common curve, wherein each outlet opening and each flow opening are bound by a plurality of fingers, each finger having a free end, wherein the free end of each finger is disposed on the common curve, and wherein a cross section of the flow openings increases toward the edge.

2. The device as claimed in claim 1, characterized in that the device is constructed substantially mirror-symmetrically.

3. The device as claimed in claim 1, characterized in that the two outer outlet openings enclose between themselves an angle of more than 20.

4. The device as claimed in claim 1, characterized in that all the outlet openings have an identical or similar cross section.

5. The device as claimed in claim 1, characterized in that the application width (B) exceeds the distance (W) of the two outer outlet openings from each other.

6. The device as claimed in claim 1, wherein the fluid is an adhesive or lotion.

7. The device as claimed in claim 1, wherein the flow fluid is compressed air.

8. A device for applying a plurality of threads of a fluid to a moving web-like substrate, having a plurality of outlet openings for the threads of fluid, wherein each outlet opening is disposed between a pair of flow openings, through which a flow fluid flows in order to achieve thread oscillation, characterized in that the outlet openings are disposed along a curved path, characterized in that two flow openings are disposed outside the respective outer outlet opening.

9. The device as claimed in claim 8, wherein the fluid is an adhesive or lotion.

10. The device as claimed in claim 8, wherein the flow fluid is compressed air.

11. A method for applying a plurality of threads of a fluid to a moving web-like substrate, wherein the fluid for the threads of fluid emerges from a plurality of outlet openings formed in a plate and disposed along a curved path, wherein each thread of fluid is flanked by two air streams discharged from respective flow openings formed in the plate and disposed along the curved path in such a way that the threads of fluid fall onto the substrate in the manner of a fan-like curtain, and wherein a cross-sectional area of a laterally outwardly positioned flow opening of the flow openings is greater than a cross-sectional area of a laterally inwardly positioned flow opening of the flow openings.

12. The method as claimed in claim 11, characterized in that the fan-like curtain spans an angle of more than 20.

13. The method as claimed in claim 12, characterized in that the fan-like curtain spans an angle of more than 30.

14. The method as claimed in claim 12, characterized in that the fan-like curtain spans an angle of more than 40.

15. The method as claimed in claim 12, characterized in that the fan-like curtain spans an angle of more than 50.

16. The method as claimed in claim 12, characterized in that the fan-like curtain spans an angle of more than 60.

17. The method as claimed in claim 11, characterized in that, in order to adjust the application width, the distance between the substrate and the outlet openings is varied.

18. The method as claimed in claim 11, wherein the fluid is an adhesive or lotion.

Description

(1) Further advantages of the invention emerge from the subclaims not cited and also from the description which now follows of the exemplary embodiments illustrated in the drawings, in which:

(2) FIG. 1 shows a first exemplary embodiment of a device according to the invention during operation, in a schematic, perspective view,

(3) FIG. 2 shows a detail view of a plate-like element as a constituent part of a nozzle module of the device from FIG. 1 to illustrate the arrangement of the outlet openings along a curved path,

(4) FIG. 3 shows a schematic illustration of an extract from the plate-like element,

(5) FIG. 4a shows, in an illustration according to FIG. 3, an exemplary embodiment modified with respect thereto,

(6) FIG. 4b shows a further exemplary embodiment in an illustration according to FIG. 4a,

(7) FIG. 5 shows a perspective view of an exemplary embodiment of a nozzle module of the device from FIG. 1 in a detailed illustration,

(8) FIG. 6 shows, in an illustration according to FIG. 5, a further exemplary embodiment of a nozzle module according to the invention having a higher number of outlet openings,

(9) FIG. 7 shows, in an illustration according to FIG. 2, a further variant of a nozzle plate analogous to the illustration of FIG. 4b,

(10) FIG. 8 shows a further exemplary embodiment of a nozzle module according to the invention in an illustration similar to that of FIG. 3, and

(11) FIG. 9 shows a further exemplary embodiment of a nozzle module according to the invention.

(12) The device according to the invention is designated in its entirety by 10 in the figures. For reasons of clarity, identical or mutually comparable parts or elements, even to the extent that different exemplary embodiments are involved, are designated by the same designations, partly with the addition of small letters.

(13) According to FIG. 1, the device 10 according to the invention is illustrated perspectively and schematically. For reasons of clarity, important parts of the device have been left out.

(14) The device 10 comprises a module 12, which is arranged above a substrate 11. The substrate 11 is in web form and has a substrate width S. The substrate is moved in the direction of movement X by drives, for example rollers, not illustrated. The nozzle module 12 is arranged in a stationary manner.

(15) Not illustrated is the holder for the module 12. Load-bearing rods or similar stand arrangements can be provided for the holder, which advantageously permit the module 12 to be displaced in a direction Y transversely with respect to the direction of movement X, and also permit locking of the selected position of the module 12 relative to the substrate.

(16) In one variant of the invention, provision can also be made in the device 10 according to the invention that a change can be made in the distance A between module 12 and substrate surface 19 or, strictly speaking, between the outlet openings 15 and the substrate surface 19.

(17) The module 12 is supplied with compressed air via a line, not illustrated, and with hotmelt adhesive or with another fluid via a further line, not illustrated.

(18) On account of a specific geometry of the outlet openings, which will be described in more detail later, the adhesive emerges from the nozzle module 12 through a plurality of outlet openings 15 as threads. Each outlet opening 15 is flanked by a flow opening 16, through which compressed air passes. As will be explained further later by using FIG. 3, the outlet openings 15 and the flow openings 16 are disposed along a curved path 22. The module 12 includes fingers 25, the fingers 25 bounding the outlet openings 15 and the flow openings 16, such that each outlet opening 15 and each flow opening 16 is bound by a pair of fingers 25.

(19) If the compressed air is switched on and the adhesive feed is open, then, in the exemplary embodiment of FIG. 1, seven threads of adhesive 17a, 17b, 17c, 17d, 17e, 17f, 17g emerge through the seven outlet openings 15. Each thread of adhesive is flanked by two lateral air flows. Because of the air flows, movements, in particular pendulum-like or oscillation-like movements, of the thread 17 occur. As soon as the thread 17 strikes the surface 19 of the substrate 11, this thread is deposited in wavy lines and the result is the coating pattern of the surface 20 illustrated schematically in FIG. 1. Because of the wavy deposition, the threads are able to form an overall very homogeneous network structure on the surface 19 of the substrate 11.

(20) As already emerges from FIG. 1, the outlet pattern of the seven threads of adhesive from the nozzle module 12 is like a starburst overall, so that the result is an adhesive thread curtain which is formed in the manner of a fan.

(21) The two air flow regions assigned respectively to each thread 17 of adhesive form and define residence regions 18a, 18b, 18c and so on for the threads of adhesive. Although this illustration should be understood as only schematic, the technical principle basically applies.

(22) As already emerges from FIG. 1, the two outermost threads of adhesive enclose between themselves an angle .sub.5. This angle is designated .sub.1, .sub.2, .sub.3 or .sub.4 in the other exemplary embodiments; it is also possible for the angle to be chosen differently if different exemplary embodiments are involved.

(23) On the basis of the choice of the relatively large angle between the two outermost threads of adhesive or between the outermost outlet openings 15, starting from a central nozzle module 12, coating is achieved not only of those regions of the surface 19 of the substrate 11 which run directly underneath the module 12, but also regions spaced apart laterally are also covered. The application width B of fluid on the substrate surface 19 which can be achieved according to FIG. 1 considerably exceeds the external dimensioning W of the nozzle module 12.

(24) For reasons of completeness, it should be pointed out at this point that the dimension W, strictly speaking, describes the distance between the two outermost outlet openings 15 for the adhesive.

(25) Depending on the choice of the distance A, the achievable application width B can be more than 1.5 times the distance W, advantageously more than 2 times, further advantageously more than 2.5 times, further advantageously more than 3 times, the distance W.

(26) In order to achieve such a fan-like formation of an adhesive thread curtain, as best emerges from the schematic sketch of FIG. 3, the adhesive outlet openings 15g, 15h and so on are disposed along a curved path 22.

(27) The curved path 22 replaces the straight line known according to the prior art.

(28) The curved form of the path 22 leads to the adhesive outlet openings 15g, 15h being aimed at the substrate surface 19 at different angles. The fan-like formation of the spray curtain according to FIG. 1 therefore arises.

(29) FIG. 3 is merely intended to illustrate schematically how a nozzle plate 13e according to the exemplary embodiment of FIG. 2, and as it is used in a device according to FIG. 1, is constructed with respect to the sequence of outlet openings 15 and flow openings 16. Here, it should be noted that FIG. 3 shows a schematic cross-sectional illustration, whereas FIG. 2 and FIG. 7 merely describe plate-like elements which merely indicate the outlet openings 15 and the flow openings 16.

(30) As indicated by FIGS. 5 and 6, a nozzle arrangement 12 is assembled in the manner of a sandwich from a plurality of plate-like elements.

(31) In the exemplary embodiment of FIG. 3, flow openings 16j, 16k and 161 and fluid outlet openings 15g, 15h and so on alternate in each case. This means that, in each case between two outlet openings 15g, 15h there is arranged exactly one flow opening 16k and between two flow openings 16j, 16k there is arranged exactly one fluid outlet opening 15g.

(32) However, the invention also covers devices according to FIG. 4a, in which each fluid outlet opening 15g is flanked by two flow openings 16f, 16g or by more flow openings and, furthermore, provision being made for two flow openings 16g, 16h to be disposed between two fluid outlet openings 15e, 15f in each case.

(33) In the exemplary embodiment of FIG. 4a, at the left-hand edge of this figure, it is indicated, merely by way of example, that the flow openings 16 do not necessarily have to run in parallel relative to the outlet opening 15 but, for example, can also be disposed at an acute angle .sub.1, .sub.2 to the outlet opening 15. In some exemplary embodiments, this can permit an advantageous flow around the adhesive thread 17.

(34) Of course, in some exemplary embodiments of the invention, flow openings 16 and outlet openings 15 oriented exclusively parallel to one another can be provided. In other exemplary embodiments of the invention, there are exclusively flow openings 16 which are not arranged parallel to the respective outlet openings. Finally, there are exemplary embodiments in which flow openings 16 and outlet openings 15 disposed in parallel and also at acute angles to one another are provided.

(35) As is revealed by the two different embodiments of FIGS. 5 and 6, for example, a nozzle module 12 can be assembled in the manner of a sandwich from various plates 13. For instance, the exemplary embodiment of FIG. 5 has a plurality of plates 13a, 13b, 13c, 13d, 13e, 13f, 13g which are held together by fixing screws 14a, 14b, 14c, 14d, 14e. To avoid repetitions, reference should hereby be made to the disclosure content of EP 0 835 952 A1, the content of which is hereby included in the content of the present patent application. The document cited already describes how precise steering of adhesive and compressed air is achieved on the basis of a sandwich structure of different plates.

(36) The plate 13e, which is significant for the invention, is shown by FIG. 2. This plate replaces the plate illustrated in FIG. 3a of EP 0 835 952 A1, it being clear to those skilled in the art that, in order to achieve a nozzle arrangement 12 according to FIGS. 5 and 6, further plates are provided, which have undergone appropriate modifications.

(37) FIG. 2 shows a plate 13k which can be used in the exemplary embodiment of FIG. 6. FIG. 6 corresponds, in terms of the basic principle, to the exemplary embodiment of the nozzle module 12a of FIG. 5, the number of outlet openings 15 having been increased in order to achieve a greater application width.

(38) While the exemplary embodiment of FIG. 5 has seven glue outlet openings 15, the exemplary embodiment of FIG. 6 has sixteen glue outlet openings. By contrast, the exemplary embodiment of FIG. 2 shows 29 glue outlet openings.

(39) The number of outlet openings depends on various parameters, such as the speed of the substrate, the desired application pattern, the type of adhesive, the available flow pressure of the compressed air and other factors. In particular, the desired application width also plays a major role.

(40) The exemplary embodiment of FIG. 4b also shows a further special feature as compared with the exemplary embodiment of FIG. 3: here, it can be seen that not just one flow opening but two flow openings are disposed outside the respective outermost fluid outlet opening 15i and 15w. Thus, a first flow opening 16n and a second flow opening 16o are disposed outside the fluid outlet opening 15i, and a first flow opening 16q and a second flow opening 16p are disposed outside the fluid outlet opening 15w. Therefore, a fluid thread 17 at the side edge, i.e. located maximally on the outside, can be drawn upward by an additional flanking applied flow, based on the image of FIG. 1. To this extent, the force of gravity is counteracted. This permits the achievement of a uniform coating of the substrate with adhesive.

(41) In a further refinement of the invention, provision is made for the flow openings 16 to have different cross sections. For instance, provision can advantageously be made in particular for a variation in the opening cross section to be made in some of the flow openings arranged on the outside, in such a way that the cross section of the flow opening increases toward the outside. The force of gravity can also be counteracted in this way and an evened-out coating can be achieved.

(42) It becomes clear to those skilled in the art that the adhesive threads which are arranged at the side edge have to cover the longest path to the substrate and, to this extent, are most intensely subjected to the influences of the force of gravity. Here, with additional flow forces, it is possible for the threads not to be deflected too much on their long path toward the substrate. As a result, this leads to a uniform application of fluid.

(43) The exemplary embodiment of FIG. 7 shows a plate 13e which is modified with respect to exemplary embodiment 2 and in whichin a way analogous to the described embodiment of FIG. 4badditional flow openings 16o and 16p are provided at the side edges.

(44) In the method according to the invention, provision can be made for the distance A between outlet openings 15 and substrate surface 20 to be varied, in order to adjust or to change the application width B.

(45) With respect to FIGS. 3 to 4b, it should further be noted that straight arrows describe the course of the flow of the compressed air or of the alternatively suitable flow fluid, whereas the wavy arrows are intended to indicate the emergence of adhesive.

(46) With respect to the figure description overall, it should be noted that this relates only to exemplary embodiments in which adhesive emerges as fluid. Other devices according to the invention, in which lotions or other fluids are used, can be operated in the same way.

(47) From FIGS. 3 to 4a and also 2 and 7 it becomes clear that the outlet openings 15 are disposed along a curved path 22 or 22. Strictly speaking, it is a matter of disposing the opening regions M of the outlet openings 15 along a curved path. In this regard, FIG. 2 shows that opening regions M.sub.1, M.sub.2, M.sub.3 and so on are disposed along the curved path 22. However, since this curved path 22 corresponds to the curved path 22 or exhibits the same curvature, the arrangement according to the invention of the outlet openings 15r, 15s, 15t can be described both by a curved path 22 and by a curved path 22.

(48) In addition, reference should now be made to the exemplary embodiments of FIGS. 8 and 9:

(49) FIG. 8 shows an exemplary embodiment of the invention in which a large number of outlet openings 15a, 15b, 15c, 15d, 15e and flow openings 16a, 16b, 16c, 16d, 16e are disposed along a curved path 22 in an alternating sequence, comparable with the exemplary embodiment of FIG. 3. The outlet openings 15 and the flow openings 16 are, however, disposed along straight sections 23a, 23b, 23c. Strictly speaking, to this extent this is a polygon. The outlet openings 15 and the flow openings 16 are disposed in this exemplary embodiment in such a way that the arrangement of these openings 15, 16 merely approximates a curved path 22.

(50) In the exemplary embodiment of FIG. 9in a way similar to that in the illustration of FIG. 8once more a polygon-like structure of the arrangement of the outlet openings 15 is made. Here, five sections 23d, 23e, 23f, 23g, 23h running in a straight line are provided, which provide an arrangement of the outlet openings 15 along a curved path 22 once more. These exemplary embodiments are also covered by the teaching according to the invention.