EP2456569B1 - Apparatus for applying glue to workpieces or webs - Google Patents

Description

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

Such a device is off US5540801 known.

For example, in the production of single-layer or multi-layered paper sacks adhesions must be made in various production steps. Thus, first the side edges of webs are wrapped and processed into a tube, wherein at least one side edge is acted upon with adhesive. The tube is singulated into pieces of tubing, to which subsequently formed soils and / or other workpieces are attached. 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, which are fastened on rollers or which are designed like a roller and which are exposed to glue. The glue is then delivered to the component to be glued according to the format. However, the present invention is not limited to the production of paper bags or sacks, but can 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 along a transport direction are passed over. Most of the workpieces to be glued touch the nozzle plate. This has a first surface, which faces the workpieces to be glued. The nozzle plate comprises a plurality of glue outlet 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 outlet openings. Each glue valve can be assigned a single glue outlet opening or a group of glue outlet openings. 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.

The Applicant of the present application has already filed a number of patent applications disclosing portions of the described apparatuses. These patent applications are inter alia under the official file number 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 been published.

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 is provided approximately a right angle. As can be seen, the edge between the two surfaces has a chamfer.

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. At the back edge of this plate, the glue often sticks and collects there. This glue accumulated there and even contaminated by foreign matter such as paper fibers can dissolve and get onto a workpiece. This workpiece can no longer be glued properly. This can, for example, result in leaks in the subsequent bag, so that the quality of such bags can be regarded as 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 the first surface and the second surface at an angle to each other, which is smaller than 90 degrees. The first surface is the surface on which the workpiece to be provided with glue or the web can be guided past. This first surface is thus facing the workpiece or the web. In this case, the second surface is a surface arranged on the rear end seen in the transport direction of the workpieces or the web and does not touch the workpiece. Both surfaces can be connected by a common edge, which often represents a so-called trailing edge, at which the workpiece loses contact with the nozzle plate. The second surface may be followed by other surfaces, in particular one which is perpendicular to the first surface. As a result, an area set back relative to the spoiler edge, ie a free space, can arise. The edge, that is to say the transitional area between the first and the second surface, can be designed in various ways. Thus, instead of a sharp edge, a chamfer may also be provided with a rounding or a small intermediate surface, these being very small in their extent with respect to the surfaces mentioned.

The angle between said first surface and said second surface is preferably substantially less than 90 degrees, for example 45 degrees. In other words, at the rear edge of the nozzle plate, a projection, which may also be referred to as nose, provided.

The advantage of such a design of the nozzle plate is the fact that the glue now does not accumulate directly on the edge, but on the second surface, which is not in contact with the workpiece or the web. Due to the angle of less than 90 of the accumulating glue is no longer or at least not so strong in contact with the workpieces, so that the risk that dissolves this Leimansammlung, compared to devices of the prior art is significantly reduced.

A further advantage of the invention is that deposits less dirt particles on the side facing away from the workpieces, since the potential contact surface for the glue is now smaller. Glue accumulations grow thereby slower than those in devices of the prior art.

In prior art devices, however, it has already been possible to interrupt production at regular intervals to remove the accumulated glue. However, frequent interruptions would have resulted in very low productivity. Of cleaning interruptions was therefore often ignored. In a device according to the invention, the cleaning can now take place in very large time intervals, so that a significant loss of productivity due to regular cleaning is avoided. Regular cleaning can therefore be carried out.

In a further embodiment of the invention, it is provided that the glue outlet openings are arranged in the transition region between the two surfaces. If, for example, this transition region is designed as a chamfer, the glue outlet openings can open at least partially in this chamfer. In other words, the glue outlet openings are arranged directly on the tip of the projection or the nose. In order to it is achieved that the glue after leaving the glue outlet openings as possible no longer comes into contact with the nozzle plate. Thus, the rate of growth of the glue pool is significantly reduced, which greatly restrains the number of low-quality bags or, with regular cleaning of the device, reduces the number of breaks in production for the purpose of cleaning.

It is advantageous if the end regions of the feed lines which supply the glue to the glue outlet openings are arranged at an acute angle to the surface region with which the workpiece or the web can be guided (guide surface). This angle can, for example, approximately halve the angle between the two surfaces, ie between the guide surface and the projection or nose bridge surface.

In an advantageous embodiment of the invention, the second surface is at least partially provided with a coating. In particular, a non-stick coating is provided. Non-stick materials that can be used at this point are known. For example, PTFE, known under the brand name "Teflon", can be provided if the glue is a water-based glue. PTFE is strongly hydrophobic. The advantage here is that the sticking tendency of the glue on this surface is greatly reduced by this measure, so that per unit of time even less glue adheres.

Another advantageous embodiment of the invention comprises further media outlet openings which are arranged in the region of the undercut and which are directed onto the surface of the undercut facing away from the workpieces. The media outlet openings can also be arranged in the nozzle plate. However, even independent media lines with media outlets are conceivable. In this embodiment, the cleaning of the nozzle plate of glue collections is now greatly simplified. This leads to an acceleration of the cleaning process, so that the time period for a cleaning cycle is shortened, which increases the productivity of the device.

Advantageously, these media outlet openings can be acted upon by medium lines with medium. The exit direction can therefore be directed directly onto the side of the projection which faces away from the workpieces, that is to say the second surface. Alternatively, however, the direction may also be directed to an adjacent surface, so that the medium is deflected when hitting the rear surface. By this arrangement, the medium can get between the second surface and the glue accumulation adhering to it, so that the Leimansammlung is detached.

It is advantageous if valves are arranged in the media lines, with which the media flow can be produced and interrupted.

Furthermore, it is provided that the medium is exposed to a higher pressure than the ambient pressure. In particular, in connection with the provision of valves so effective cleaning can be achieved.

As a medium water, water vapor or air is advantageously provided. In particular, with steam good results could be achieved in experiments. The effects of moisture in connection with the air flow allowed quick dissolving of glue accumulations.

Fig. 1

Seitenansicht einer schematisch dargestellten, erfindungsgemäßen Vorrichtung.

Fig. 2

Vergrößerte Darstellung des Bereiches der Figur 1, der mit einem gestrichelten Rechtseck umgeben ist.

Further embodiments of the invention will become apparent from the description of the drawings. The figures show:

Fig. 1

Side view of a schematically illustrated, inventive device.

Fig. 2

Enlarged view of the area of the FIG. 1 which is surrounded by a dashed right-sided.

Fig. 1 and Fig. 2 show a device 1 for providing flat workpieces or webs with glue. In this figure, however, only individual workpieces are shown. In practice, these are, for example, pieces of hose 2. Generally, webs are used to form hoses along Longitudinal seams provided with glue. Hose pieces may be provided with glue, for example, to glue on or stick on valve leaflets, inner latches or ground cover sheets. Also, the bonding of floor flaps done (so-called soil bonding). Even in the production of bags, 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-up end does not yield back, the back of the surface is supported by an abutment 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 the 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, ie 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.

The surface 13 can also be regarded as limited in the transport direction x by the lines A and B. The lines are in the FIG. 1 out of the drawing plane so that they are only recognizable as dots in the figure.

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. Said undercut 14 can be produced, for example, by a machining method such as milling.

The rear, second surface 18 is in the FIG. 1 bounded by the lines B and C. The surfaces 13 and 18 enclose an angle α which may be between 0 and 90 degrees, for example at 45 degrees. Also the line C stands on the drawing level and can be like the lines A and B in the FIG. 1 only be shown as a dot.

The invention can also be defined in another way. Thereafter, as seen in the transport direction x, the line C is arranged in front of the line B.

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 deserves special attention. This runs obliquely in the transport direction of the hose pieces 2, where they exactly in the edge 15, which connects the surfaces 13 and 15, opens. The angle of the glue line 22 is advantageously as large as the angle between the surface 13 and the bisector between the surfaces 13 and 18. The axis of the glue line can lie on or parallel to said bisecting line.

The advantageous embodiment of the gluing head described in the two preceding paragraphs combines further advantages in itself: The described undercut 14 allows the glue, which is not taken along by the hose piece 2, to collect on the rear surface 18, so that the probability of this glue accumulation is taken by a contact with a piece of tubing 2 and so leads to contamination, is reduced. The described arrangement of the glue outlet openings 23 also contributes to the fact that the leaked glue barely makes contact with the outer surfaces of the gluing head 9 so that the glue does not adhere to these surfaces. The amount of glue that collects on the gluing head is thus greatly reduced.

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.

In summary, the described embodiment shows a device with which the contamination of the tube pieces 2 is greatly reduced and can be easily cleaned. LIST OF REFERENCE NUMBERS 1 Device for providing flat workpieces or webs with glue 2 hose Connector 3 transport device 4 End of the hose piece 2 5 counter support 6 conveyor belt 7 cylinder 8th cylinder 9 Beleimungskopf 10 nozzle plate 11 nozzle body 12 pressure plate 13 Surface of the pressure plate 14 undercut 15 rear edge 16 rear surface 17 head Start 18 rear surface 19 Valve 20 feed 21 glue line 22 glue line 23 glue outlet 24 cleaning device 25 valves 26 supply lines 27 fluid line 28 fluid line 29 extension 30 Fluid outlet opening A line B line C line F Leimflussrichtung x Transport direction of the hose pieces 2 y Main extension direction of the hose pieces 2 Z Direction orthogonal to the xy plane α Angle between the first plane 13 and the second plane 18th

Claims (8)

1. Apparatus (1) for applying glue to workpieces or webs, which apparatus comprises a nozzle plate (10) past which the workpiece (2) or the web can be conducted in a transport direction (x) and which comprises at least one glue outlet opening (23), wherein at least one glue valve (19) is arranged on or in the nozzle plate (10), with which glue valve a flow of glue between a glue reservoir and/or glue supply lines (20) and the at least one glue outlet opening (23) can be produced and can be interrupted such that the glue can be applied in a desired format to that surface of the workpiece (2) or of the web which is to be glued,
   wherein the nozzle plate comprises a first surface (13) which faces the workpiece or the web, and a second surface (18) which is arranged at the rear end of the nozzle plate, as seen in the transport direction (x), wherein the first surface (13) and the second surface (18) take up an angle (α) which is less than 90 degrees with respect to each other,
   characterized in that further media outlet openings (30) are arranged in the region of the rear end of the nozzle plate.
2. Apparatus (1) according to Claim 1, characterized in that the glue outlet openings (23) are arranged in the transition region between the first surface (13) and the second surface (18).
3. Device (1) according to either of the preceding claims, characterized in that at least end regions of the supply lines (22) which supply the glue to the glue outlet openings (23) are arranged at an acute angle to the first surface (13) with which the workpiece (2) or the web can be conducted.
4. Apparatus (1) according to one of the preceding claims, characterized in that the media outlet openings (30) can be charged via media lines (26, 27, 28) with medium which can be conducted onto the at least one surface (16, 18).
5. Apparatus (1) according to the preceding claim, characterized in that valves (25) with which the flow of the medium to the media outlet openings can be produced and can be interrupted are arranged in the media lines.
6. Apparatus (1) according to either of the two preceding claims, characterized in that the medium is exposed to a higher pressure than the ambient pressure.
7. Apparatus (1) according to one of the three preceding claims, characterized in that the medium is water, water vapour or air.
8. Apparatus (1) according to one of the preceding claims, characterized in that at least the second surface (18) and/or the first surface (13) are provided at least in regions with a coating, in particular a non-stick coating.

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