EP2684702A2 - Device for applying adhesive and method for operating such a device - Google Patents

Abstract

The apparatus has an application nozzle (1) for applying adhesive to a book block spine (4). The application nozzle is line-connected to an adhesive supplying system. The application nozzle comprises a chamber (10) for providing adhesive and arranged adjacent to the nozzle opening, and another chamber (12) is arranged between a nozzle opening (3) and the supplying system. A slide (6) is arranged in a region of the former chamber for changing width (8) of the chamber, and another slide (11) is arranged in a region of another chamber for changing the volume (21) of the latter chamber. An independent claim is also included for a method for adapting an adhesive application nozzle.

Description

The invention relates to a device for applying adhesive according to the preamble of claim 1, a method for adapting an adhesive application nozzle according to claim 5 and a further device for applying adhesive according to the preamble of claim 10.

State of the art

In book-making in the perfect binding method, adhesive is either applied to a book spine using roller applicators or alternatively with application nozzles. The adhesive is dispersion adhesives, hot melt adhesives or dispersion / hot melt adhesive combinations. In the past few years, the adhesive polyurethane (PUR for short) has been found to be a hotmelt adhesive, which has particularly good blade tear resistance and achieves particularly advantageous results in the book block 180 ° impact behavior, the so-called lay-flat behavior. This adhesive can also be advantageously used for poorer paper quality, for example coated papers in which the proportion of coating components outweighs the fiber content required for the strength, and which can also roughen poorer to expose the fiber for bonding.
The terms glue and glue are used synonymously below.

The problem with the use of PUR is the limited applicability for Walzenauftragswerke, since the relatively thin adhesive layers of a few 100 micrometers in a roll applicator are technically difficult to control, and the adjustment, operation and cleaning is very high. Moreover, the adhesive in contact with the environment releases harmful isocyanates, which also limits the usefulness of the PUR adhesive for roller applicators. In addition, the PUR cures prematurely in an oxygen atmosphere and under the influence of humidity especially in traditional roll coaters which have a large surface area to the atmosphere. This disadvantage of the Walzenauftragswerke is particularly evident in short runs and frequently changing paper types, as they are increasingly caused by digital printing.

To circumvent these disadvantages, nozzle application systems are increasingly being used, such as in US 4,667,879 . EP 1 033 262 and EP 550 913 shown. Common to all these publications is the search for ways to vary the width of the adhesive trace. This is important for nozzles, since, unlike in a roller application system, the adhesive outside the surface to be bonded can not flow back into the system and so contamination of the system or a higher-level device can not be avoided if the nozzle is set too wide.

The nozzles are positioned according to the desired adhesive thicknesses on the spine at a distance to this. Furthermore, the nozzle is adjusted to product thickness. From the dimensions of the product thickness, layer thickness and order length, the necessary adhesive application volume for a book block can be calculated. Since the adhesive application takes place in the passage of the book block, the necessary order volume per time is determined, which is e.g. can accurately feed a gear pump.

The setting of the application nozzle depending on the product thickness is realized by the release of a job slot by axially or radially moving slide. This releases a space under the slot and filled with adhesive, the width of which is proportional to the product thickness.

Solutions for adjusting the nozzle width, for example, are already known from the US 4,667,879 , of the DE 100 23 895 and the EP 1 033 262 ,

The EP 2 319 707 discloses a device for applying adhesive to a book block spine by means of a nozzle. To apply a finely-bound size film, the adhesive supply is clock-controlled. For this purpose, a controllable feed pump and a switchable valve are provided in the adhesive supply. In order to finish the adhesive supply faster and to break the glue film clean is between valve and nozzle placed an adhesive retractor. This adhesive retractor receives adhesive from the moment the glue application is completed on the book block.

With an inline linkage of one or more digital presses with an adhesive line, the profitability can be significantly increased if different batches can be manufactured with varying formats, without a production interruption is required (selective binding). Likewise, it must be ensured that the first product of a new lot is salable (edition 1). Thus, the so-called Einrichteausschuss is no longer acceptable.

When back gluing through a nozzle application system with slider in the adhesive chamber, there is the problem that when changing the product thickness, the adhesive level does not remain constant.

When enlarging the size of the adhesive level drops in the chamber of the application nozzle and the subsequent product is not supplied with adhesive in the front area.

With a size reduction, the adhesive will swell out of the die slot and cause smearing as the resulting product impacts this adhesive swell. The falling adhesive level at format enlargement can be relatively easily compensated by the pump nachfördert a defined amount of adhesive in the chamber.

task

The object of the present invention is to provide a device for applying adhesive and to describe a method for adapting an adhesive application nozzle, which overcome the disadvantages of the prior art and also allow for a conversion to a narrower book block back a clean adhesive application.

This object is achieved by a device for applying adhesive with the features of claim 1, by a method for adapting an adhesive application nozzle according to claim 5 and by a device for applying adhesive with the features of claim 10.

The device according to the invention serves to apply adhesive to a book block spine of a book block by means of an application nozzle. The application nozzle is conductively connected to an adhesive supply system and has a nozzle opening which is changeable and adaptable to the thickness of a book block to be processed. Advantageously, the application nozzle has a first chamber for providing adhesive which is adjacent to the nozzle opening and a second chamber which is arranged between the nozzle opening and the adhesive supply system. The term "chamber" here means a volume having space, channel o. .. The application nozzle further has a first slide in the region of the first chamber for varying the width of the first chamber and a second slide in the region of the second chamber for changing the Volume of the second chamber. The second chamber may have an elongated extent or have a round configuration. In the case of elongated extension of the slider can be moved translationally in the chamber. In the case of the round design, the slider can be moved in rotation. The second chamber thus provides a variable volume reservoir which can be used to hold excess adhesive when switching from a book block of greater thickness to a book block of lesser thickness, or to release additional glue from a book block of lesser thickness to a book block larger thickness is converted. This will ensure that excess adhesive will not cause an adhesive bead when changing the nozzle opening, which could either stick the applicator nozzle or contaminate the book block.

In a particularly advantageous and therefore preferred embodiment of the device according to the invention, a drive is assigned to the first and the second slide, both drives being connected to a common control unit in terms of data transmission, so that the drives can be controlled by the control unit. The data transmission can be done via cable or wirelessly, eg by radio. A respective drive can be designed, for example, as a stepper motor. It is particularly advantageous if the drives are controllable in such a way that when changing the width of the first chamber depending on the thickness of each book block to be processed, the sum of the volume of the first chamber and second chamber remains constant. In other words, such that the adhesive, which is displaced by the displacement of the first slider, is received by the second chamber. The second chamber thus represents a compensation reservoir.

According to a first variant of a development of the device according to the invention, the thickness of a respective book block to be processed is stored in the control unit. The book block thickness can be provided by an order management system. In an alternative development, the device has a measuring device for detecting the thickness of a book block to be processed, which is arranged upstream of the application nozzle and data transmission technology connected to the control unit.

In both cases, a very fast adjustment of the application nozzle is guaranteed so that so-called "selective binding" is made possible and books with "edition 1" in the required quality wetted with adhesive and can be produced without waste.

• In einem ersten Schritt wird der erste Schieber verschoben zur Veränderung der Breite einer ersten Kammer, in welcher Klebstoff an einer Düsenöffnung bereitgestellt wird. Die Verschiebung geschieht derart, dass die Breite der ersten Kammer an die Dicke eines jeweils zu verarbeitenden Buchblocks angepasst wird.

The invention also relates to a method for adjusting an adhesive application nozzle of a device for applying adhesive to a book block back, in particular as described above. The method is adapted to the thickness of a book block to be processed and has the following steps:

• In a first step, the first slider is displaced to vary the width of a first chamber in which adhesive is provided at a nozzle opening. The displacement takes place in such a way that the width of the first chamber is adapted to the thickness of a respective book block to be processed.

In a second step, which takes place at the same time, a second slide is displaced, which is assigned to a second chamber between the nozzle opening and an adhesive supply system. The displacement occurs in such a way that the sum of the volume of the first and second chamber remains constant. The displaced by the first slider adhesive volume is thus absorbed in the second chamber by a retreat of the second slider.

In an advantageous embodiment of the method according to the invention, the second step is performed only when the width of the first chamber is reduced, so when switching to a narrower book block. In this case, adhesive is displaced by the first slider, which should not escape through the nozzle opening of the application nozzle, since otherwise a bead of adhesive would be formed at the nozzle opening or on the book block back.

In an advantageous development of the method according to the invention, in an additional step, the second slide is returned to its starting position, in which the second chamber has its minimum volume. Starting from the starting position thus achieved, the second slide can subsequently be used again for the volume compensation in a further reduction of the width of the first chamber. It is particularly advantageous if the resetting of the second slider takes place in coordination with the activation of the adhesive supply system and / or if the resetting of the second slider takes place in a plurality of small steps. Both of the above approaches can be used to ensure that there is not too much glue on the nozzle opening at any moment which could not be picked up by the book block spine.

In an advantageous development of the method according to the invention, the ratio of the displacement speed of the first and second slides is inversely proportional to the ratio of the cross sections of the first and second slides. It is thereby achieved that the volume of the second chamber is reduced to the same extent, i. increases as quickly as the volume of the first chamber is reduced.

The invention also relates to an alternative apparatus for applying adhesive to a book block spine by means of an applicator nozzle, wherein the applicator nozzle is conductively connected to an adhesive supply system and wherein a nozzle opening of the applicator nozzle is changeable and adaptable to the thickness of a book block to be processed. According to the invention, the application nozzle has a chamber adjacent to the nozzle orifice and a diaphragm for volume balance of the chamber, the diaphragm being disposed adjacent to the chamber. Furthermore, a slider intended to change the width of the chamber. If adhesive is displaced during displacement of the slide to reduce the width of the chamber, the membrane is expanded and provides a compensation space in which the displaced adhesive can be accommodated. For this purpose, the membrane is made of an elastic material. This device has the advantage that only a small structural change of the application nozzle is required and with simple means an adhesive bead can be prevented due to superfluous adhesive.

The described invention and the described advantageous developments of the invention are also in any combination with each other advantageous developments of the invention.

With regard to further advantages and constructive and functional aspects of advantageous embodiments of the invention, reference is made to the dependent claims and the description of embodiments with reference to the accompanying drawings.

embodiment

Fig. 1

eine Klebstoffauftragsvorrichtung in einer Übersichtsdarstellung

Fig. 2a

die Klebstoffauftragsvorrichtung mit Einstellung für einen breiten Buchblockrücken

Fig. 2b

die Klebstoffauftragsvorrichtung mit Einstellung für einen schmalen Buchblockrücken

The invention will be explained in more detail with reference to preferred embodiments. It show in a schematic representation

Fig. 1

an adhesive applicator in an overview

Fig. 2a

the adhesive applicator with setting for a wide book block back

Fig. 2b

the adhesive applicator with setting for a narrow book block back

Corresponding elements and components are provided in the figures with the same reference numerals.

An adhesive application device 100 has an adhesive application nozzle 1, which carries an adhesive application head 2 with a nozzle slot 3, via which the adhesive 19 is transferred to the book block back 4 of a book block 22. The book block 22 is held by a clamp 23 and moved away in the transport direction T via the adhesive application device 1. The nozzle slot 3 is opened or collapsed according to the book block thickness 5 to be glued by means of a first slider 6. The slider has a defined cross-sectional area 7 and offers through the respective opening width 8, which corresponds to the book block thickness 5, a defined volume of adhesive 9 place.

From a premelter 18 will - as in Fig. 1 represented - the molten adhesive 19 pumped via a heating hose 14 to a first closed valve 15 and the heating hose 16 back into the premelter by means of pump 20. As soon as adhesive is to be applied to the spine 5, the valve 15 opens and the adhesive is pumped via the channel 17 into the chamber 10.

If the application width of the slit nozzle 3 is reduced because instead of a wide book block back 4 - as in Fig. 2a shown - now a narrow book block back 4 - as in Fig. 2b shown - is to be wetted with adhesive 19, the first slider 6 is displaced by a drive 25 as indicated by arrow a and he displaces the adhesive located in the first chamber 10 19. It is simultaneously from a further drive 25, a second slide eleventh in a second chamber 12 as indicated by arrow a so shifted that the total volume of the first chamber 10 and the second chamber 12 is maintained in the adhesive application head 2 and the excess adhesive 19 can escape via a channel 13 into the second chamber 12. That is, the volume 9 in the first chamber 10 is reduced to the same extent as the volume 21 in the second chamber 12 is increased. At this moment, the total volume is constant regardless of the position of the first slider 6 in the adhesive application head 2. Thus, the second slider 11 can be brought back to its standby position, in which the volume 21 is almost zero, the adhesive located in the second chamber 12 19 is pushed back in very small doses to the first chamber 10 and imperceptibly transmitted to the book block back 4. If, in this phase, an opening of the nozzle slot 3 is necessary because of a book block 4 with a larger book block thickness 5, the adhesive 19 is primarily provided from the second chamber 12 and the pump capacity of the pump 20 is increased only when necessary. This can be guaranteed that even with constant change between minimum and maximum product thickness 5, no excess adhesive 19 is provided on the nozzle slot 3 and applied to the book block back 4.

In the illustrated embodiment, the slide 6, 11 are arranged in parallel, one above the other and connected frontally via a channel 13. However, the second chamber 12 could also be at the same height as the first chamber 10, on the opposite side of the nozzle slot. 3

LIST OF REFERENCE NUMBERS

1

Klebstoffauftragsdüse

2

Glue gun

3

nozzle slot

4

Book block spine

5

Book block thickness

6

first slide

7

Cross sectional area of first slider

8th

opening width

9

Adhesive volume of the first chamber

10

first chamber

11

second slider

12

second chamber

13

intermediate channel

14

Airbag

15

Valve

16

Airbag

17

channel

18

Premelter

19

adhesive

20

pump

21

Adhesive volume of the second chamber

22

book block

23

Book block clamp

24

measuring device

25

drive

26

control unit

100

Apparatus for applying adhesive

T

Direction of movement of the book block bracket

a

Movement of the slide

Claims (10)

Device (100) for applying adhesive (19) to a book block spine (4) by means of an application nozzle, wherein the application nozzle (1) is conductively connected to an adhesive supply system (14, 15, 16, 17, 18, 20) and wherein a nozzle opening ( 3) of the application nozzle (1) is variable and adaptable to the thickness (5) of a book block (22) to be processed,
characterized,
in that the application nozzle (1) has a first chamber (10) for providing adhesive (19) adjacent to the nozzle opening (3) and a second chamber (12) arranged between the nozzle opening (3) and the adhesive supply system (14, 15 , 16, 17, 18, 20), and in that a first slide (6) in the region of the first chamber (10) for changing the width (8) of the first chamber (10) and a second slide (11) in the region the second chamber (12) for changing the volume (21) of the second chamber (12) is provided. Device for applying adhesive according to claim 1,
characterized,
in that each of the first (6) and second (11) slides is assigned a drive (25), both drives (25) being connected to a common control unit (26) in terms of data transmission technology. Device for applying adhesive according to one of claims 1 or 2,
characterized,
in that the drives (25) are activatable in such a way that when the width (8) of the first chamber (10) changes as a function of the thickness (5) of a book block (22) to be processed, the sum of the volume (9 + 21) of the first (10) and second (12) chamber remains constant. Device for applying adhesive according to claim 2 or 3,
characterized,
that in the control unit (26) to be processed, the thickness (5) of each Book block (22) is deposited or,
that the control unit (26) with a measuring device (24) for detecting the thickness (5) of a book block to be processed (22) is data-communicatively connected. Method for adapting an adhesive applicator nozzle (1) to a device (100) for applying adhesive (19) to a book block spine (4), in particular according to one of the preceding claims, to the thickness (5) of a book block (22) to be processed following steps: a) shifting (a) a first slide (6) for changing the width (8) of a first chamber (10) in which adhesive (19) is provided at a nozzle opening (3), such that the width (8) of the first chamber (10) is adapted to the thickness (5) of a book block (22) to be processed, b) simultaneous displacement of (a) a second slide (11) which is associated with a second chamber (12) between the nozzle opening (3) and an adhesive supply system (14, 15, 16, 17, 18, 20), such that the sum the volume (9 + 21) of the first (10) and second (12) chamber remains constant. A method for adjusting an adhesive application nozzle according to claim 5, wherein step b) is performed only when the width of the first chamber (10) is reduced. A method of adjusting an adhesive applicator nozzle according to any of claims 5 or 6, comprising the additional step c) returning (a) the second slide (11) to its initial position in which the second chamber (12) has its minimum volume. Method for adapting an adhesive application nozzle according to claim 7,
the resetting of (a) the second slider (11) in coordination with the Actuation of the adhesive supply system (14, 15, 16, 17, 18, 20) takes place and / or wherein the resetting (a) of the second slide (11) takes place in a plurality of smaller steps. Method for adapting an adhesive application nozzle according to one of claims 5 to 8,
wherein the ratio of the displacement speed of the first (6) and second (11) slides is inversely proportional to the ratio of the cross sections of the first (6) and second (11) slides. Device for applying adhesive (19) to a book block spine (4) by means of an application nozzle (1),
wherein the application nozzle (1) is conductively connected to an adhesive supply system (14, 15, 16, 17, 18, 20) and wherein a nozzle opening (3) of the application nozzle (1) changeable and to the thickness (5) of a book block to be processed (22 ) is customizable,
characterized,
in that the application nozzle (3) has a chamber (10) adjacent to the nozzle opening (3) and a membrane-like surface element for volume compensation of the chamber (10), wherein the membrane-like surface element is arranged adjacent to the chamber (10) and that a slide ( 6) is provided for changing the width of the chamber (10).

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