EP1156931B1 - Adhesive application station for printed products - Google Patents

Abstract

The adhesive-applicator unit incorporates an applicator-head (12) for the adhesive and a slide surface (16) for the printed products (10). A thrust piece (22,28) for the printed products is situated on each side of the slide surface. A slot-shaped nozzle for the adhesive extends over the entire width of the slide surface. An adhesive-accumulator is in the form of a pressure compartment. At least one side thrust piece (22,26,32) inside a narrow tolerance range of different thicknesses for the stacked printed products is in the form of side guide surfaces. A movable thrust piece (26,32) always covers the outlet slit (20) of the slot-shaped nozzle.

Description

The invention relates to an adhesive application station for binding stacked Print products by means of a flowable or liquefiable Adhesive, which application station has an application head for the adhesive a sliding surface for the printed products, on both sides of this sliding surface one stop for these printed matter and one over the whole Width of the sliding surface extending slot nozzle for the adhesive, a as Pressure chamber trained adhesive storage and means for generating a Includes pressure in the adhesive store.

All kinds of printed matter are used for the production of books, magazines, Brochures and the like are initially stacked and fixed in a holder. Then the So-called back surface milled flat and roughened at the same time. So can the adhesive subsequently applied can be better absorbed. at insufficient adhesive absorption, the binding quality is bad, the bound Printed matter falls apart or individual sheets when used dissolve. However, the applied adhesive layer does not only have to be every single one Bind firmly, but also be so elastic that in the bound Printed products can be browsed easily.

The originally practiced application of an adhesive with a brush or an equivalent mean has been simplified with advancing development so that the prepared back surface of a stack over at least one in an adhesive bath immersed roll can be pulled. This open system However, it also has the disadvantage that, for example, in the case of a moisture-reactive Polyurethane glue due to the action of air and heat change the chemical and physical properties. Same or similar Problems can arise with all known adhesives, which can be used as cold glue, hot glue or hot melt (thermoplastic adhesive). Have been advantageous from economic and ecological considerations e.g. aqueous polyurethane dispersions, which are PU dispersions for short to be named. PU is a group of high-molecular materials which by polyaddition of diisocyanates and bi- or multifunctional Hydroxyl compounds are prepared. They are in their molecules Basic building blocks connected by the urethane group (-NH-COO-). Depending on the The chemical nature of the starting compounds used can be polyurethanes obtained with linear, branched or cross-linked macromolecules. Linear polyurethanes are thermoplastic materials that have a wide range of uses have found. Only cross-linked, elastomeric polyurethanes are of interest here, which are suitable as elastic, water and heat resistant glue are.

Glue application stations are known which work with slot nozzles. The prepared back surface of a stack of printed matter is between two stops over a sliding surface with an exit slot for the adhesive drawn. The slot nozzle releases adhesive during this short time. Although successively stacks with the same number of printed matter pulled through, they are not exactly the same width. The different In special cases, stack widths can deviate by up to ± 1 mm. Even in the area of one and the same stack, width differences in the Range of a few tenths of a millimeter. This results in the problems in practice, for example with glue cords on the bound print product.

EP, A1 0550913 describes an adhesive application station with two different ones Stacking heights manually adjustable, which are the side guide jaws form. With slightly different stack heights at least adjusted a screw or clearance between jaws and stack in Purchase. This has a greater effort or education of ugly glue lines. To overcome these drawbacks one sealing block each is inserted in the jaws.

The invention is therefore based on the object of an adhesive application station for binding stacked printed products of the type mentioned at the beginning to create, which eliminates the problems with the different stack widths.

The object is achieved in that at least one side Stop as different within a narrow tolerance range Thicknesses of the continuous stacked printed products automatically compensating lateral guide surface is formed, and in this tolerance range traceable movable stop always sealing on an outlet slot the slot nozzle for the adhesive lies in the sliding surface. Specific and further embodiments of the adhesive application station are the subject of dependent claims.

Since a stack always has the same number of printed products, which are made up of are cut out of the same print carrier web, are the tolerance ranges experience shows that it is very tight. Even in large stacks they are in usually at a maximum of approximately ± 0.5 mm, in exceptional cases at a maximum of approximately ± 1mm.

In practice, the most economical solution is to have an order header with a fixed stop and a resilient stop within the tolerance range for the stacked printed products to be bound. The Feeding the stack is preferably facilitated by the fact that the guide surfaces narrow in the direction of insertion up to the area of the slot nozzle. This can be in the form of bevels, but also of curved ones Areas.

• Nach einer ersten Variante kann ein geführter Schlitten als ganzes federnd auf einem Düsenblock des Auftragskopfs in Richtung des Austrittsschlitzes verschiebbar sein und mit seiner Führungsfläche einen federnden Anschlag bilden.
• Nach einer weiteren Variante kann eine in einem positionierbaren Halter in Schlitzrichtung verschiebbare, zweckmässig zylindrische Rolle mit zur Gleitfläche rechtwinkliger Achse, Führungsfläche sein.
• Nach einer Variante ist ein in Schlitzrichtung geführter Schieber mit einer entsprechend ausgebildeten stirnseitigen Führungsfläche ausgebildet. Der Schieber ist in Richtung des Führungsschlitzes, beispielsweise gegen den Widerstand einer Feder oder gegen einen pneumatischen Druck, verschiebbar und in einem exakt positionierbaren Niederhalter angeordnet.
• Nach einer letzten hier erwähnten Variante ist eine Blattfeder auf einem bereits erwähnten positionierbaren Halter stirnseitig so angeordnet, dass sie eine in Schlitzrichtung um etwa ± 1 mm elastisch verformbare Führungsfläche bildet. Es sind verschiedene Arten von Blattfedern geeignet, welche gleichzeitig im Toleranzbereich von etwa ± 1 mm den Austrittsschlitz abdecken.

The stop resilient in the slot direction with a guide surface can be designed according to different variants, regardless of whether a fixed stop is designed or both stops are resilient:

• According to a first variant, a guided carriage as a whole can be displaceably resilient on a nozzle block of the application head in the direction of the outlet slot and can form a resilient stop with its guide surface.
• According to a further variant, a suitably cylindrical roller, which can be displaced in the slot direction in a positionable holder and has an axis perpendicular to the sliding surface, can be a guide surface.
• According to a variant, a slide guided in the slot direction is formed with a correspondingly designed front guide surface. The slide is displaceable in the direction of the guide slot, for example against the resistance of a spring or against pneumatic pressure, and is arranged in a hold-down device that can be positioned exactly.
• According to a last variant mentioned here, a leaf spring is arranged on the end face of a positionable holder already mentioned in such a way that it forms a guide surface which is elastically deformable in the slot direction by approximately ± 1 mm. Different types of leaf springs are suitable, which simultaneously cover the outlet slot in the tolerance range of approximately ± 1 mm.

As already indicated, the movable stop, preferably by spring force, automatically traceable. In the same way, the movable stop be pneumatically cushioned. Since the necessary tolerance range, such as also mentioned, is very narrow and usually only a fraction of a millimeter the movable stop must be able to be positioned exactly.

Furthermore, the movable one resting on the outlet slot for the adhesive must be Cover this so well that the bound stack of printed matter no glue lines arise. Since the stops with the side Guide surface, apart from the variant with a leaf spring, anyway are solidly trained, this is basically not a problem. A short one Use or a thickening in a leaf spring can also serve this purpose fulfill

In the interaction of the outlet slot for the adhesive with an immediate dosing shaft arranged underneath, which e.g. a continuous one has diagonal longitudinal slot, the slot nozzle is formed. The The metering shaft in turn limits an adhesive store designed as a pressure chamber, which is arranged in or below the application head and in direct connection with an adhesive dispenser, for example a pressure barrel. This has the advantage that was previously not possible, that the adhesive from the pressure barrel to the outlet slot in the application head never Air contact has what the chemical and physical mentioned above Changes prevented.

For the generation of the necessary pressure in the adhesive store is after a preferred variant, a directly acting printer stamp Pressure cylinder provided in a pneumatic pressure accumulator. The necessary However, pressure can also be hydraulic, electromagnetic or with a Spindle are generated.

The pressure can and should change in relation to the machine speed become.

For the use of a hot glue, especially a hot melt, is in the glue storage arranged at least one heating cartridge, which is useful is sensor controlled. With the help of a temperature sensor, the adhesive on the temperature required for the optimum viscosity.

Each time adhesive is dispensed through the exit slot, there is one per se known automatic pressure compensation, which in the system with the pneumatic Pressure accumulator is integrated.

All stops with the guide surfaces for the stacks to be bound by Printed matter preferably consists of wear-resistant, polished material, because the print medium, especially paper, drawn over it, like a Emery cloth works. Special steels, hard metals, ceramic materials or Cermets are suitable materials for guide surfaces.

• Fig. 1 eine Prinzipskizze des Bindebereichs eines Auftragskopfs eines Kleberauftragssystems in Draufsicht,
• Fig. 2 eine Prinzipskizze eines Drucksystems mit Druckausgleich im Schnitt,
• Fig. 3 eine Draufsicht auf eine Kleberauftragsstation,
• Fig. 4 eine Ansicht von Fig. 3,
• Fig. 5 eine Seitenansicht von Fig. 3 (von links),
• Fig. 6 einen Auftragskopf in Draufsicht,
• Fig. 7 einen Düsenblock von Fig. 6,
• Fig. 8 eine Seitenansicht von Fig. 6 (von rechts),
• Fig. 9 einen Fixanschlag,
• Fig. 10 einen Niederhalter in Draufsicht,
• Fig. 11 eine Seitenansicht von Fig. 10 (von links),
• Fig. 12 eine Schieberplatte in Draufsicht, auseinander gezogen,
• Fig. 13 eine Einstellschraube für einen Niederhalter,
• Fig. 14 einen Führungsblock für die Einstellschraube, und
• Fig. 15 eine Dosierwelle.

The invention is explained in more detail with reference to exemplary embodiments shown in the drawing, which are also the subject of dependent claims. They show schematically:

• 1 is a schematic diagram of the binding area of an application head of an adhesive application system in plan view,
• 2 is a schematic diagram of a printing system with pressure compensation in section,
• 3 is a plan view of an adhesive application station,
• 4 is a view of FIG. 3,
• 5 is a side view of FIG. 3 (from the left),
• 6 is an application head in plan view,
• 7 shows a nozzle block from FIG. 6,
• 8 is a side view of FIG. 6 (from the right),
• 9 is a fixed stop,
• 10 a hold-down device in plan view,
• 11 is a side view of FIG. 10 (from the left),
• 12 is a slide plate in plan view, pulled apart,
• 13 an adjusting screw for a hold-down device,
• Fig. 14 is a guide block for the adjusting screw, and
• 15 shows a metering shaft.

Fig. 1 shows the basic principle of binding stacked printed products 10 on an application head 12 of an adhesive application station 14 (FIGS. 3 to 5). A Sliding surface 16 of a nozzle block 18 of the application head 12 is from one in Longitudinal exit slit 20 for an adhesive 52 (FIG. 2) penetrated. In the present case, the slot width s is the exit slot 20 at about 0.2 mm. This slot width is usually not changeable, it can also be adjustable.

The sliding surface 16 is laterally from a fixed stop 22 with a first guide surface 24, including a guide 24a, and a hold-down device 26 with a second guide surface 28, including a guide 28a for a printed product 10, limited The hold-down 26 is in the direction of Double arrow 30, which runs parallel to the outlet slot 20, and exactly positionable. The hold-down 26 guides a slide 32, which within a narrow tolerance range t in the direction of the also parallel to the outlet slot 20 extending double arrow 34 against a resilient force can be pressed into the hold-down device 26. The slide 32 has a third guide surface 36 for stacked printed products 10, likewise with a guide 36a. Both this third guide surface 36 and the first guide surface 24 are angled and widen as a guide 24a, 36a against the insertion direction E for stacked printed products 10 on. The narrow tolerance range t for the slide which can be traced by spring force 32 is through a bore 38 in the holding-down device 26 and one in this bore limited by the slider 32 projecting bolt 40.

For the time being, the hold-down device is used to bind stacked printed products 26 with the slider 32 corresponding to the minimum thickness d of the stacked Printed products 10 positioned and e.g. set with a screw. at a tolerance range of, for example, 0.5 mm for the thicknesses d of the stacked Printed products, the width g of the sliding surface 16 to the distance d + t set, provided the slide 32 is at maximum tolerance t pressed in flush with the second guide surface 28. Impression of the Slide 32 takes place when stacked printed products 10 are introduced, if this along guides 24a, 36a of the first and third guide surfaces 24, 36 can be pushed. When the exit slot 20 is reached the adhesive application is mechanical, electronic or sensor controlled and is terminated when the printed product 10 reaches the area of the exit slot 20 leaves.

Both the hold-down 26 and the slide 32 seal the exit slot 20 if and where they rest on the sliding surface 16.

When guiding the stacked printed products 10 over the outlet slot 20 these are pressed by the slide 32 onto the first lateral guide surface 24. The second guide surface 28 does not act as such in the present case, the stacked printed products 10 slide along the third guide surface 36 with guide 36a. When binding according to Fig. 1 there are differences regarding the thickness d of the stacked printed matter 10 both automatically balanced within the same batch as well as from batch to batch, an adhesive leak next to the printed products 10 cannot occur, causing not only a loss of glue, but also the formation is avoided by ugly glue lines.

According to a variant of the basic principle, not shown, the slide 32 omitted and the hold-down 26 itself as resilient in the tolerance range movable stop be formed. In this case, the stacked ones slide Printed products 10 along the second guide surface 28 with a guide.

The functional description of Fig. 1 is drawn by the reverse Fig. 2 added. A slot nozzle 42 is outlined in the application head 12, which the exit slot 20 shown in Fig. 1 and one in a bore of the application head Includes 12 guided metering shaft 44 with a diagonal slot 46. This extends over the length of the outlet slot 20.

Below the metering shaft 44, which is rotatable in the direction of the double arrow 48, is a arranged as a pressure chamber adhesive store 50 which with a dissolved or melted adhesive 52 is filled. In a pressure accumulator 54 a pressure cylinder 56 with a pressure stamp 58 is arranged, which can be moved in the direction of the double arrow 60 and into the adhesive store 50 protrudes.

The printing system for the adhesive application shown in FIG. 2 is in the middle position. The diagonal slot 46 communicating with the adhesive is closed.

Are stacked printed products 10 (Fig. 1) along the over a guided inclined insertion ramp 62 extending sliding surface 16, switches the Control the metering shaft 44 immediately when it reaches the outlet slot 20 in the working position shown in dashed lines, the diagonal slot 46 of the In this position, the metering shaft 44 connects the adhesive store 50 to the Exit slot 20. Immediately after the stacked printed matter 10 den Have left the area of the outlet slot 20, the sensor-controlled conducts Electronics turn the metering shaft 44 into the rest position, the glue supply to the exit slot 20 is prevented.

The pressure loss that occurs due to the release of adhesive in the adhesive store 50 is automatically compensated by the pressure stamp 58 accordingly is pushed deeper into the adhesive store 50. The pressure in the adhesive store 50 is determined by the cross-sectional ratio of the impression cylinder 56 to the pressure stamp 58 and the pressure in an antechamber 64 of the pressure accumulator 54 determined. The pressure in this antechamber is in the range of, for example 0.7 to 0.8 bar.

Of course, the binding process for the stacked printed products can 10 can also be done manually or semi-automatically.

A basic design principle of an adhesive application station 14 is shown in FIG. 3 to 5 shown. The functional division into application head 12, adhesive storage 50 (pressure chamber) and pressure accumulator 54 can be seen. The essential Individual elements of the application head 12 are shown in detail in FIGS. 6 to 15 shown.

The application head 12 comprises a nozzle block 18 as a carrier, which as a profile trained or milled or drilled out of a solid block.

At the one end of the nozzle block 18 there is a fixed stop 22 with the first lateral stop Guide surface 24 attached. This fixed stop is within the limits a short slot 66 can be positioned without fine adjustment.

A hold-down 26 is over the area of a much larger elongated hole 68 positionable. The end of the hold-down device 26 is the second lateral guide surface 28 trained. On the opposite of the fixed stop 22 A front end of the nozzle block 18 is screwed to a guide block 72, which for precise positioning of the hold-down 26 by an adjusting screw 74 is reached. This adjusting screw 74 also includes a knurled nut 76 an adjustment scale 78, which can also be designed as a vernier. Of course can, according to further, not shown variants of the hold-down 26 can also be automatically positioned using other means known per se be, for example with a linear motor, stepper motor, hydraulic or pneumatic means.

In a corresponding bore of the nozzle block 18 is one with the outlet slot 20 the slit nozzle 42 forming metering shaft 44 which via a pivotable lever 80 is manually or automatically operated by machine.

The application head 12 is directly with a separate, designed as a pressure chamber Adhesive reservoir 50 screwed and sealed. A filler neck 82 for the adhesive store 50 has an external thread and can thus directly with an interchangeable, larger adhesive reservoir can be connected, for example a barrel pump. This means that the adhesive is absolutely free of air guaranteed. The prevention of the Contact of adhesive with air has been reached.

The pressure accumulator 54 is connected to the adhesive accumulator via four spacer tubes 84 50 connected. In Fig. 4, a bore 86 for compressed air is indicated, which includes the usual connection fittings not shown. The print medium is guided into an anteroom (64 in FIG. 2) and acts on one with a broken line indicated pressure cylinder 56, which multiplies the pressure proportional to the area transfers into the adhesive store 50 via a pressure stamp 58.

6 shows an application head 12 in plan view, it essentially corresponds - but reversed - Fig. 3. For clarity especially the fixing screws for the fixed stop 22 and the hold-down 26, there are only the holes 88.90 for bolts in the Elongated holes 66, 68 can be seen.

6 shows not only the outlet slot in the longitudinal direction 20 for the adhesive, but also longitudinal guide elements. The sliding surface 16 is angled slightly downward along an edge 92 and thus forms an inclined insertion ramp 62 for easier insertion of the stacked printed matter. A hardly noticeable first gradation 94 and a larger gradation 96 also serve for easier attachment the hold-down 26, the fixed stop 22 and the guide block 72.

The width g of the sliding surface 16 is practically at the maximum possible value set. You could add a little by moving the fixed stop 22 can be enlarged. The minimum width g of the sliding surface 16 is due to the Length of the elongated holes 66 and in particular 68 limited.

A set screw 98 can be seen in the hold-down device 26. With this, the spring force of the slide 32 guided by the hold-down device 26 (FIG. 1) become.

7 shows a nozzle block 18 without additional elements. It corresponds essentially Fig. 6. However, it is not a first step 94 as a guide element educated. This ensures an improved sliding surface 16. The bore 100 with an internal thread serves to receive a fastening screw for the guide block 72.

The side view of FIG. 6 shown in FIG. 8 (from the right) shows hatched lines the end face of the nozzle block 18. Below the guide block 72 with the Knurled nut 76 is part of the adjustment plate 70 and at the bottom part of the Hold-down 26 visible.

In the reinforced face of the nozzle block 18, the is pivotable mounted metering shaft 44 recognizable, its pivot lever (80 in Fig. 4) is the Clarity omitted.

There is also a heating cartridge 102 and a temperature sensor in the nozzle block 18 104 supported, which is the setting of the correct adhesive temperature in the application head 12 serve.

In a recess 106 electrical cables, distributors and the like can be electrical Components are stored.

A hold-down 26 with an integrated slide 32 is shown in FIGS. 10, 11 and 12. 10 shows the slider 32 projecting approximately 0.4 mm with the third lateral guide 36, which according to FIG. 1 with formation of the third guide 36a is slightly angled. The slide 32 can against the resistance of a coil spring 106 is pressed into the hold-down device 26 until the second guide surface 28 with the third guide surface 36 runs flush. The stroke restriction of the slide 32 is as already mentioned ensured by the bolt 40 in the bore 38. The hold-down 26 is penetrated in the longitudinal direction by a bore 108, which free space for the adjusting screw 70 creates.

The second guide surface 28 of the hold-down device 26 is visible in FIG. 11. The second guide surface 28 is around an edge 110 to form a guide 26a slightly angled together with the guide 24a of the first guide surface 24 of the fixed stop 22 (FIG. 9) results in a wider insertion opening for the stacked printed products. The slider 32 or its third guide surface 36 is also angled to a shifted Edge 112. For better guidance in the hold-down device 26, the slide 32 a flat longitudinal groove 114 of shallow depth.

As shown in Fig. 12, the slide 32 has a bore 116 with an internal thread into which a spiral spring 116 and a corresponding ball 118 be pushed. The spring can be preloaded with a set screw 98 become.

13 and 14 is an adjusting screw 74 with knurled nut 76 and Classification 78 together with the associated guide block 72 with a corresponding one Hole 120 shown with internal thread. A shaft lock 122 is also hinted at.

A metering shaft 44 shown in FIG. 15 has a shaft lock at one end 122 equipped and another is a swivel lever 80 for manual or mechanical application of a torque attached. An Allen screw 126, which with its tip in a conical recess of the Metering shaft 44 is secured prevents the lever 80 from turning empty.

In the left area of the metering shaft there is a longitudinal groove, which is functional corresponds to a diagonal slot 46 (FIG. 2). There is also a radial channel 124 provided, which with the dosing shaft in the working position Secures glue supply.

Claims (10)

1. Adhesive application station (14) for binding stacked printed products (10) by means of a liquid or liquefiable adhesive (52), where the application station (14) comprises

   an application head (12) for the adhesive (52) with a slip surface (16) for the printed products (10), and on both sides of this slip surface (16) a stop (22, 26) for these printed products (10) and a slot nozzle (42) extending over the entire width (g) of the slip surface (16) for the adhesive (52),

   an adhesive reservoir (50) formed as a pressure chamber, and

   means for generating a pressure in the adhesive reservoir (50),

   characterised in that
   at least one side stop (22, 26, 32) is formed as a side guide surface (24, 24a, 28, 28a or 36, 36a) which automatically compensates within a narrow tolerance range (t) for different thicknesses (d) of the stacked printed products (10) passing through, and a stop (26 or 32) returnably movable within this tolerance range (t) always lies tightly sealing on an outlet slot (20) of the slot nozzle (42) for the adhesive (52) in the slip surface (16).
2. Adhesive application station (14) according to claim 1, characterised in that the tolerance range (t) is up to around ± 1 mm, preferably around ± 0.5 mm.
3. Adhesive application station (14) according to claim 1 or 2, characterised in that a fixed stop (22) and a stop (26 or 32) resilient within the tolerance range (t) are formed, preferably with side guide surfaces (24, 28, 36) tapering in the introduction direction (E) of the printed products (10) as deflectors (24a, 28a, 36a).
4. Adhesive application station (14) according to any of claims 1 to 3, characterised in that the stop (26 or 32) resilient in the slot direction with the guide surface (28, 28a, 36, 36a) is a carriage guided mechanically or pneumatically as a whole on a nozzle block (18), a roller guided in a positionable holder, a slide (32) guided in a positionable retainer (26) or a leaf spring guided in a positionable holder.
5. Adhesive application station (14) according to claim 4, characterised in that the stop is returnably movable with preferably adjustable spring force or pneumatically.
6. Adhesive application station (14) according to any of claims 1 to 5, characterised in that the width (s) of the outlet slot (20) is adjustable.
7. Adhesive application station (14) according to any of claims 1 to 6, characterised in that the slot nozzle (42) comprises a manually or mechanically controlled rotatable metering shaft (44) directly below the outlet slot (20) with a longitudinal slot (46) which extends over the entire length of the outlet slot (20) and in the working position of the metering shaft (44) connects the outlet slot (20) with the directly-connected adhesive reservoir (50).
8. Adhesive application station (14) according to claim 7, characterised in that an integral accumulator (54) is formed with means acting on the adhesive reservoir (50) arranged directly in or below the application head (12) and thus guarantees automatic pressure compensation after every adhesive discharge.
9. Adhesive application station (14) according to claim 8, characterised in that a pressure cylinder (56) acts by means of the accumulator (54) by way of a plunger (58) directly on the adhesive (52) in the adhesive reservoir (50).
10. Adhesive application station (14) according to any of claims 1 to 9, characterised in that in the application head (12) and/or in the adhesive reservoir (50) is arranged at least one sensor-controlled heating cartridge (102).

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