WO2011009913A1 - Preventing glue buildup on a nozzle plate - Google Patents

Abstract

The invention relates to a device (1) for providing flat workpieces or webs with glue, comprising a nozzle plate (10) past which the workpiece or the web can be fed in a transport direction (x), and comprising a plurality of glue outlet openings. A plurality of glue valves (19) are disposed on or in the nozzle plate, by means of which a glue flow between a glue reservoir and/or glue feed lines (21, 22) and glue outlet openings (23) can be produced and interrupted, so that the glue can be applied to the surface of the workpiece (2) or the web to be glued in a desired format. At least one fluid outlet opening (30) is provided on or in the nozzle plate (10), through which a fluid can be fed.

Description

 UNDER-CONNECTION OF GLUE STORAGE TO A SHOWER PLATE

The invention relates to a device for providing workpieces or webs with glue according to the preamble of claim 1 and a method according to the preamble of claim 7.

In the production of single-layer or multi-layered paper sacks, adhesions have to be bonded in various production steps (hose production, base molding). The material of these sacks, here paper and / or plastic, is provided with glue, often starch glue, so that different components of the later sacks can be joined together. In this case, the gluing must be done according to a specified pattern in order not to cause unwanted gluing. For many years, format parts have been used for this purpose, which are fastened on rollers or which are designed like a roller and which are exposed to glue. The glue is then dispensed according to the format to be glued to the component of the workpiece or the web. However, the present invention is not limited to the production of paper bags or sacks, but may also be used in the processing of any workpieces or webs, especially in the field of packaging.

The Applicant has recently developed alternative devices which eliminate the need for the aforesaid format parts and associated rollers. Such a device comprises a nozzle plate, on which the workpieces or the webs can be guided along a transport direction. Most of the workpieces to be glued touch the nozzle plate. These has a first surface, which faces the workpieces to be glued. The nozzle plate comprises one or more glue stoma openings, from which glue emerges, which then adhere to the areas of the workpieces to be glued. Furthermore, glue reservoirs and / or glue lines are provided with which the required glue can be provided. In order to obtain a size-appropriate glue application, glue valves are provided between the glue reservoirs and / or glue lines and the glue ports. Each glue valve can be assigned a single glue outlet or a group of glue ports. With the glue valves, the glue flow between the glue reservoirs and / or glue lines and the glue outlet openings can be produced and interrupted. By selective control of the valves so a desired glue format can be applied directly to the workpiece to be bonded. The bringing together of the components to be bonded takes place in the transport direction behind the device just described and will not be described in detail here. In principle, however, the invention is not limited to devices with a nozzle plate. For example, individual nozzles can be fastened to a frame. These can then be arranged on a line which runs transversely to the transport direction of the workpieces. The nozzles can then, in contrast to the nozzle plate, be arranged contactlessly to the workpiece.

The Applicant of the present applications has already filed a number of patent applications disclosing portions of the described apparatuses. These patent applications have been published inter alia under the official file numbers DE 103 09 893 A1, DE 103 27 646 A1, DE 102 42 732 A1, DE 103 30 750 A1 and DE 103 30 751 A1. The content of these applications is hereby incorporated in this application. In particular, the first-mentioned patent application shows in its figure 11 a structure of such a device, but in which the nozzle plate between the first plane or the first surface on which the workpieces or the web are passed, and seen in the transport direction of the workpieces or the web rear, second surface approximately a right angle is provided. As can be seen, the edge between the two surfaces has a chamfer. In principle, however, the first and the second surface can also be arranged at another, arbitrary angle. Although the described devices have already proven themselves in practice, the shortcomings described below occur at times. When the glue has been applied to the material, it is initially in contact with the nozzle plate. In particular, at the rear edge - the so-called spoiler edge - this plate or on the adjoining this edge surface, the glue often stick and collects there. This glue accumulated there and even contaminated by foreign matter such as paper fibers can dissolve and unintentionally get onto a workpiece. This workpiece can no longer be glued properly. This process may, for example, result in leaks in the later bag or unintentional splices, so that the quality of such bags is considered to be impaired.

The object of the present invention is therefore to improve the described device so that the quality of the bags produced therewith is improved.

The object is achieved by a device which comprises in addition to the preamble features of claim 1 and its characterizing features. Accordingly, it is provided that at least one fluid outlet opening is provided on or in the nozzle plate. By means of this fluid outlet opening, a fluid can now be conducted with which the glue accumulation can be detached from the nozzle plate and / or with which it is avoided that a glue accumulation will ever occur. In this case, the fluid is provided in at least one fluid reservoir and directed in a suitable manner to the fluid outlet opening. The fluid outlet opening is advantageously arranged at the rear end of the nozzle plate, so that the fluid, which exits, for example, as a directed fluid jet from the at least one opening, can act directly on the Leimansammlung. A Glue collection can be removed very quickly, reliably and easily.

The at least one fluid port may be introduced into the nozzle plate, for example bored. But it can also be incorporated in a separate component, this component can then be attached to the nozzle plate in a suitable manner familiar to those skilled. But a Fluidusthttsöffnung can also be the end of a line, such as a hose. In an advantageous embodiment of the invention, at least one fluid line is provided, which connects the fluid outlet opening with a fluid reservoir. This fluid conduit may, for example, comprise one or more holes in the nozzle plate or be in a separate component which may be suitably secured to the nozzle plate. However, the fluid lines can also comprise further lines, such as tubes or tubes. The fluid reservoir can thus be arranged at a remote location, which offers sufficient space.

In an advantageous embodiment of the invention, at least one valve is provided with which the fluid outlet can be controlled or regulated. As a control or controlled variable here are about the amount and time and - take the fluid outlet. The at least one valve may accordingly be provided as a simple switching valve or as a control valve. The flow rate can also be adjusted via a controllable pump. For the construction of a control circuit, a suitable sensor, which measures the flow rates, can also be provided. With this embodiment, it is possible to ensure a just needed for the replacement or avoidance of Leimansammlung fluid application without wasting fluid. The number of valves can be chosen differently. In view of the costs, it may be advantageous to provide as few valves as possible. If, however, only a portion of the glue valves and glue outlet openings is used more frequently during the gluing of the workpieces, it may be advantageous to provide only cleaning in the region of these glue outlet openings. A higher number of valves would then be provided. Various formations and arrangements can be provided for the fluid outlet openings. It is advantageous, when viewed in the transport direction, in each case a fluid outlet opening is arranged in a line behind a Leimausthttsöffnung. It is to be expected that the glue accumulates particularly behind a glue outlet opening, so that an arrangement of a fluid outlet opening in this area enables easy cleaning. In another advantageous embodiment of the invention, the fluid outlet openings are arranged offset from the glue outlet openings, so that, for example, the area of two glue outlet openings can be cleaned with a fluid outlet opening.

In a further advantageous embodiment, the at least one fluid outlet opening is formed as a gap or slot, which or which extends transversely to the transport direction. This covers such a gap or such a slot several glue outlet openings or even almost the entire width of the nozzle plate. The big advantage of this arrangement is the fact that a homogeneous fluidity allows a very effective cleaning. A suitable configuration of the end regions of the fluid line is of course necessary in order to distribute the fluid evenly over the entire gap width.

It is advantageous if water, water vapor, air or anti-adhesive agents are to be provided as fluids. The device may be operable with one or more of these fluids. Thus, it may be provided to use an anti-adhesive agent before the start of production or even during production, so as to reduce the adhesion tendency of the glue. Such antiblocking agents may be, for example, silicone spray or Teflon spray. This procedure is particularly worth mentioning, as this prevents the onset of glue accumulation. The onset of a glue accumulation often acts as a germ on which further glue can easily accumulate. The growth of a glue collection therefore does not run linearly with time or with the number of glued workpieces, but has a greater dependence. It may thus be advantageous to continuously guide a fluid through the fluid outlet openings.

If such a Leimansammlung nevertheless occurred, it can be easily removed by applying, for example, water, water vapor and / or air. Other fluids are conceivable here. Such cleaning advantageously takes place when no workpiece or web is within the influence of the fluid. For this purpose, the current production can be interrupted. However, it can also be provided to carry out a cleaning during production when a certain area of the bag or the bag itself has just left the device and a not yet glued bag has not reached the area of influence of the fluid outlet opening. To free the nozzle plate, it is thus advantageous to allow the fluid to emerge from the fluid outlet openings at intervals (path or time).

Likewise, it is advantageous to combine the continuous passage and the intermittent passage of fluids through the fluid outlet openings with each other. In this way, for example, the number of production interruptions can be kept low. In this case, it may be advantageous to provide multiple fluid reservoirs, each containing a fluid. It can even be provided decoupled fluid outlet openings. This means that fluid outlet openings, lines, valves and other components associated therewith are uniquely associated with a fluid reservoir.

In a concrete embodiment of the method according to the invention it is provided that in operation, a gaseous fluid, preferably air, is passed through the fluid outlet openings and that in production interruptions, a gaseous or a liquid fluid, preferably water, is passed through the fluid outlet openings.

Further embodiments of the invention will become apparent from the description and the claims. The individual figures show:

Fig. 1 side view of a schematically illustrated, inventive

 Contraption.

Fig. 2 Enlarged view of the area of Figure 1, which is surrounded by a dashed right-hand corner, but with a slightly different arrangement of the lines.

Fig. 3 side view of another schematically illustrated

 Embodiment of the invention

Fig. 4 perspective view of a nozzle plate

Fig. 5 perspective view of another nozzle plate

Fig. 6 illustration of the cleaning process

Fig. 1 shows a device 1 for providing flat workpieces or webs with glue. In this figure, however, only individual workpieces and no webs are shown. In practice, these are, for example, pieces of hose 2. Generally, webs are provided with glue for forming hoses along longitudinal seams. Hose pieces can be provided with glue, for example, to glue on or stick on valve leaflet, inner latch or bottom cover sheets. The latter workpieces may also need to be provided with glue. In addition, the bonding of floor flaps can take place (so-called floor bonding). Even in the production of sacks, therefore, there are numerous applications for the device according to the invention. The tube pieces 2 are conveyed by an indicated transport device 3 in the transport direction x, which runs transversely to the main extension direction y of the tube pieces 2, through the device 1. The ends of the tube pieces 2, of which only one is shown, have been raised to form flaps and folded triangular pockets. This wound-up end forms an area that is orthogonal to the main extension direction of the tube piece 2 (direction z). The front of this surface, which is thus facing away from the main part of the hose piece 2, must be freely accessible for gluing with glue. So that during the gluing process the wound end does not yield back, the Back of the surface supported by a counter 5. In the illustrated embodiment, this counter-5 comprises an endless conveyor belt 6, which rotates about two cylinders 7 and 8, of which at least one is driven. The abutment may also comprise a rotating cylinder or even a fixed baffle.

On the front of the floors, a gluing head 9 is provided, which ensures the glue application according to the desired format. This gluing head 9 comprises a nozzle plate 10, which can be subdivided into a nozzle body 11 and a pressure plate 12. The two latter elements 11 and 12 are shown separately in the figure, but may also be integrally formed. The conveyor belt 6 facing first surface 13 of the pressure plate 12 may form a small angle with the conveyor belt 6, so that conveyor belt 6 and first surface 13 form an inlet funnel, d. H. the distance between the two surfaces decreases in the transport direction x. Thus, the piece of tubing can be pressed against the conveyor belt 6, without being kinked or damaged.

As seen in the direction of the hose pieces 2 at the rear end of the pressure plate 12, this is provided with an undercut 14. This means that the rear surface 16 slightly springs back relative to the rear edge 15. This has the consequence that a projection 17 is formed, which has a rear, second surface 18, which faces away from the hose piece 2.

The gluing head 9 comprises a plurality of valves 19, to which glue can be supplied from a glue reservoir, not shown, via the feed line 20, this glue being under an overpressure. With the valve 19, a glue flow can now be produced, which can be supplied via the glue lines 21 and 22 of the glue outlet opening 23. The direction of the glue flow is indicated by the arrow F. The glue lines 21 and 22 can branch, so that a plurality of glue outlet openings can be loaded with glue via a valve. The glue lines 21, 22 may be introduced as holes in the material. The glue line 22 extends obliquely in Transport direction of the hose pieces 2, where it opens exactly in the edge 15, which connects the surfaces 13 and 15.

Said projection 17 has advantages, since relatively little glue accumulates on its rear surface 18. Nevertheless, such Leimansammlungen can lead to the disadvantages mentioned above. The accumulating glue can be removed from time to time. For this purpose, the gluing head comprises a cleaning device 24. This comprises further valves 25 to which a cleaning fluid is provided via the supply lines 26. A valve 25 can now establish the connection to the fluid lines 27 and 28, so that the fluid can escape from the fluid outlet openings 30. The fluid line 28 is introduced into an extension piece 29, which, however, can also be designed in one piece with the nozzle body 11 and / or the pressure plate 12. The fluid line 28 is oriented so that the outflowing fluid can reach the rear surface 16 and from there flow along the rear surface 18, so that it peels off the glue accumulation. For this purpose, the axis of the fluid line 28 with the rear surface 18 at an acute angle, ie an angle between 0 and 90 degrees, preferably 10 to 80 degrees, a. The exit of the fluid from the fluid exit ports 30 may also serve to wet the surfaces 16 and 18 with a fluid having an anti-sticking property so that the tendency of the glue to adhere to the surface 16 and / or 18 is reduced. FIG. 2 shows a detail of FIG. 1 in an enlarged view, wherein, however, the fluid lines 27 and 28 are arranged differently in comparison with FIG. These are not performed in this embodiment by the nozzle body 11, but outside of the nozzle body 11. The fluid lines 27 and 28 may consist of suitable tubes or hoses.

FIG. 3 again shows a device 1 for providing flat workpieces or webs with glue, but in which the nozzle head has a different design compared with the device of FIG having. In this embodiment, no protrusion is provided with an undercut, so that this nozzle head comprises only a rear surface 16. This surface occupies an angle of approximately 90 degrees with the surface 13. The glue outlet openings 23 are now arranged in the surface 13. Compared to Figure 1, the cleaning device 24 is not changed in terms of their design and function. However, the according to FIG

2 modified cleaning device can with the embodiment of FIG.

3 combined. FIG. 4 shows a gluing head 9 according to FIG. 3 in a perspective view. In this view, the glue outlet openings 23 on the surface 13 are now clearly visible. The size of the glue outlet openings is shown exaggerated. In practice, they may be much smaller in relation to the area 13. The number of glue outlet openings 23 may be larger in practice than shown here. The fluid outlet opening is shown in this figure as a slot 31. In the simplest embodiment of this slot can be acted upon via a single valve 25 with a fluid. This embodiment is shown in FIG. Nevertheless, a plurality of valves 25 can also be provided, via which the wide slot 31 can be supplied with a fluid. Thus, two valves can be provided, one of which can connect a first fluid reservoir, with which a cleaning fluid can be provided, to the wide slot 31, and of which the other can connect a second fluid reservoir, with which an anti-adhesive fluid can be provided, to the wide slot 31. The wide slot 31 may be configured as a nozzle, so as to produce a directed fluid jet, which is directed against the rear surface 16.

FIG. 5 shows a further embodiment of the invention. Here, the fluid outlet openings 30 are designed circular, wherein the size and the number of these openings 30 may differ significantly in practice from the drawing. Each valve 25, the number of which is arbitrary in FIG. 5, may provide one or more openings 30 with fluid. FIG. 6 again shows sections from FIG. 3, the flow path of the cleaning fluid now being illustrated by short arrows 32. The fluid flow is directed against the surface 16 and deflected therefrom, so that the fluid enters the area between the surface 16 and the glue pool 33 and the glue pool 33, which has formed in the region of the tear-off edge 34, disengages from the surface 16 , This cleaning process can be carried out from time to time during a production standstill. Alternatively, such a cleaning process can also be carried out during production, if there is no hose piece 2 in the region of the glue outlet openings 23 or the area of the hose is not critical with regard to small soiling. In particular, when providing webs with glue, there is always a web section in the region of the device. There may be areas where cleaning does not have a detrimental effect. In this way, even small glue accumulations 33 can be removed before they continue to grow. Such a cleaning can for example be done after passing each piece of tubing, however, larger cleaning intervals may be advantageous. In the figures 1 to 6 advantageous features of the invention have been explained with reference to various embodiments. Although features are shown only in individual embodiments, so various features can be combined arbitrarily. Such combinations do not cause difficulties for the person skilled in the art.

Claims

claims 1. Device (1) for providing workpieces or webs with glue,  which comprises a nozzle plate (10), on which the workpiece or the web can be guided in a transport direction (x) and which comprises at least one glue outlet opening (23),  wherein a plurality of glue valves (19) are arranged on or in the nozzle plate, with which a glue flow between at least one glue reservoir and / or at least one glue supply line (21, 22) and the glue outlet opening (23) can be produced and interrupted, so that the glue is applied to the glue To be glued surface of the workpiece (2) or the web in a desired format can be applied.  characterized in that  on or in the nozzle plate (10) at least one fluid outlet opening (30) is provided, through which a fluid can be conducted. 2. Device (1) according to the preceding claim,  characterized in that  at least one fluid line (26, 27, 28) is provided, which connects the fluid outlet opening (30) with a fluid reservoir. 3. Device (1) according to one of the preceding claims, characterized in that for controlling or regulating the fluid outlet at least one valve (25) is provided. 4. Device (1) according to one of the preceding claims,  characterized in that  a plurality of fluid outlet openings (30) are provided, which are arranged in the transport direction (x) directly behind the glue outlet openings (23) or offset therefrom. 5. Device (1) according to one of the preceding claims,  characterized in that  the at least one fluid port opening is designed as a gap (31) or oblong hole, which or which extends essentially transversely to the transport direction (x). 6. Device (1) according to one of the preceding claims,  characterized in that  as fluid water, water vapor, air or an anti-adhesive agent is provided. 7. Method for providing workpieces (2) or webs with glue,  in which the workpiece or the web in a transport direction (x) on a nozzle plate (10) is passed over  wherein the glue is passed through glue exit openings (23) onto the workpiece or the web,  wherein by means of glue valves (19) which are arranged on or in the nozzle plate (10), a glue flow between a glue reservoir and / or Leimzuführleitungen (21, 22) and glue outlet openings (23) is made or interrupted, whereby the glue to be glued to the Surface of the workpiece (2) or the web is applied in a desired format,  characterized in that a fluid is passed through at least one fluid outlet opening (30) onto at least one outer wall (16, 18) of the nozzle plate (10). 8. Method according to the preceding claim,  characterized in that  the passage of the fluid takes place when no workpiece or web is provided with glue. 9. Method according to claim 7,  characterized in that  the passage of the fluid is permanent. 10. The method according to one of the three preceding claims,  characterized,  that during operation a gaseous fluid, preferably air, is passed through the fluid outlet openings and  that in production interruptions, a gaseous or a liquid fluid, preferably water, is passed through the Fluidusthttsöffnungen. 11. Method according to one of the four preceding claims,  characterized in that  Before the start of production a fluid with anti-adhesive properties is passed through the fluid outlet openings.