Device for applying a flowable substance to a substrate

Abstract

A device for applying a flowable substance to at least one substrate includes an applicator nozzle in the form of a slotted nozzle which has a stationary nozzle body with an inlet opening, a flow duct, and a nozzle slot, wherein the flowable substance is delivered through the applicator nozzle and passes from the inlet opening into the flow duct and from there to the nozzle slot, and is discharged through an outlet opening of the nozzle slot that is arranged in an outer region of the nozzle body, wherein the applicator nozzle further has a slide valve movable relative to the nozzle body in the longitudinal extent of the outlet opening and contacts the outer region of the nozzle body for modifying the covering of the outlet opening. The longitudinal extent of the flow duct is at least as great as the longitudinal extent of the nozzle slot.

Claims

1. A device for applying a flowable substance to at least one substrate, comprising: an applicator nozzle comprising a stationary nozzle body having an inlet opening, a flow duct, and a nozzle slot; wherein, with reference to an orthogonal coordinates system having a direction X, a direction Y and a direction Z, a cross-sectional area of the flow duct which extends in the direction Y is defined by a plane in the direction X and the direction Z, a width of the nozzle slot which extends in the direction Y is defined in the direction X, and a depth of the nozzle slot which extends in the direction Y is defined in the direction Z; wherein when the flowable substance is delivered through the applicator nozzle, the flowable substance passes from the inlet opening into the flow duct and from the flow duct to the nozzle slot, and is discharged through an outlet opening of the nozzle slot; wherein the outlet opening is arranged in an outer region of the nozzle body; wherein the applicator nozzle further has a slide valve operable to be moved relative to the nozzle body in the direction Y to define a longitudinal extent of the outlet opening for modifying a covering of the outlet opening; wherein a longitudinal extent of the flow duct in the direction Y is at least equal to a longitudinal extent of the nozzle slot in the direction Y; wherein the inlet opening is in fluid communication with the flow duct in the region of a first end of the flow duct and a second end of the flow duct is in the region of a first end of the nozzle slot; wherein the outlet opening is configured to be covered by the slide valve starting from a second end of the nozzle slot; wherein the cross-sectional area of the flow duct decreases in the direction Y from the first end of the flow duct to the second end of the flow duct, while a volume of the flow duct defined by the cross-sectional area from the first end of the flow duct to the second end of the flow duct remains constant; wherein the width of the nozzle slot is constant or increases over its progression in the direction Y from the second end of the nozzle slot to the first end of the nozzle slot and the depth of the nozzle slot is constant or decreases over its progression in the direction Y from the second end of the nozzle slot to the first end of the nozzle slot; and wherein the width of the nozzle slot and the depth of the nozzle slot are not both constant.

2. The device as claimed in claim 1, wherein at least one of the flow duct and the nozzle slot have an unmodifiable volume.

3. The device as claimed in claim 1, wherein an actuator for interrupting the flow of the flowable substance into the flow duct is arranged upstream from the inlet opening and is in a closed position when the slide valve is displaced.

4. The device as claimed in claim 1, wherein at least one of a change in the cross-sectional area of the flow duct over its length, a change in the width of the nozzle slot over its length, and a change in the depth of the nozzle slot over its length is non-linear.

5. The device as claimed in claim 1, wherein the cross-sectional area of the flow duct at the second end of the flow duct is no more than half as large as the cross-sectional area of the flow duct at the first end of the flow duct.

6. The device as claimed in claim 1, wherein the shape of the cross-sectional area of the flow duct is the same at the first end of the flow duct and at the second end of the flow duct.

7. The device as claimed in claim 1, wherein the nozzle body has a first nozzle body part and a second nozzle body part that are connected to each other to form the flow duct and the nozzle slot.

8. The device as claimed in claim 7, wherein at least one of the flow duct and the nozzle slot is formed exclusively by depressions in one of the first nozzle body part and the second nozzle body part.

9. The device as claimed in claim 6, wherein the cross-sectional area of the flow duct at the first end of the flow duct and at the second end of the flow duct has a semi-circular shape.

10. The device as claimed in claim 7, wherein the flow duct and the nozzle slot are formed in one of the first nozzle body part and the second nozzle body part, and wherein the inlet opening and a feed line to the inlet opening are formed in the other one of the first nozzle body part and the second nozzle body part.

11. The device as claimed in claim 1, wherein at least one of the outlet opening, the nozzle slot, and the flow duct is arranged horizontally or vertically with respect to the extent in the direction Y.

12. The device as claimed in claim 1, wherein the nozzle body is planar in the outer region and the slide valve has a planar portion for contacting the nozzle body in the outer region for sealing contact with pretensioning.

13. The device as claimed in claim 1, wherein the outlet opening is configured to be entirely covered by the slide valve.

14. The device as claimed in claim 1, further comprising a feed guide provided with a bearing surface arranged perpendicular to the longitudinal extent of the outlet opening and the slide valve has a bearing surface on a side facing the feed guide arranged parallel to the bearing surface of the feed guide, and wherein the bearing surface of the feed guide and the bearing surface of the slide valve each have surface regions which form converging insertion surfaces for the substrate.

15. The device as claimed in claim 1, further comprising a conveying device for moving the substrate over the nozzle body in the region of the outlet opening, and wherein the conveying device has an arrangement of transport clamps for clamping the substrate while the substrate is being moved.

16. The device as claimed in claim 1, wherein the flowable substance is flowable adhesive and the inlet opening, the flow duct, and the nozzle slot of the applicator nozzle are configured to deliver the flowable adhesive through the applicator nozzle.

17. The device as claimed in claim 1, wherein the flowable substance is hot melt adhesive and the inlet opening, the flow duct, and the nozzle slot of the applicator nozzle are configured to deliver the hot melt adhesive through the applicator nozzle.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) The invention is illustrated in the drawings with reference to exemplary embodiments in a schematic view, without being limited thereto.

(2) FIG. 1 shows an adhesive binder, shown for areas which are relevant in terms of a device according to the invention.

(3) FIG. 2 shows the adhesive binder according to the view in FIG. 1, in a detailed view in terms of part regions.

(4) FIG. 3 shows a book spine with applied adhesive.

(5) FIG. 4 shows an application station of the adhesive binder, illustrated in a three-dimensional view.

(6) FIG. 5 shows the application station in a view V according to FIG. 4.

(7) FIG. 6 shows the application station in a view VI according to FIG. 5.

(8) FIG. 7 shows the application station in a view VII according to FIG. 5.

(9) FIG. 8 shows the applicator nozzle used in the application station, shown for a first exemplary embodiment, illustrated with no slide valve, in a three-dimensional view.

(10) FIG. 9 shows the arrangement shown in FIG. 8 in a three-dimensional view, viewed from a different direction.

(11) FIG. 10 shows the arrangement according to FIG. 8 in a view X according to FIG. 8.

(12) FIG. 11 shows a view XI according to FIG. 10.

(13) FIG. 12 shows a view XII according to FIG. 10.

(14) FIG. 13 shows a section along the line XIII-XIII in FIG. 11.

(15) FIG. 14 shows a section along the line XIV-XIV in FIG. 11.

(16) FIG. 15 shows the arrangement in the view according to FIG. 10, with internal regions additionally illustrated by means of dot-dashed lines.

(17) FIG. 16 shows a section along the line XVI-XVI in FIG. 15.

(18) FIG. 17 shows a section along the line XVII-XVII in FIG. 15.

(19) FIG. 18 shows a section along the line XVIII-XVIII in FIG. 15.

(20) FIG. 19 shows a section along the line XIX-XIX in FIG. 15.

(21) FIG. 20 shows the applicator nozzle used in the application station, shown for a second exemplary embodiment, illustrated without a slide valve, in a view according to FIG. 15.

(22) FIG. 21 shows a section along the line XXI-XXI in FIG. 20.

(23) FIG. 22 shows a section along the line XXI I-XXII in FIG. 20.

(24) FIG. 23 shows a section along the line XXIII-XXIII in FIG. 20.

(25) FIG. 24 shows a section along the line XXIV-XXIV in FIG. 20.

(26) FIG. 25 shows an adhesive flow diagram for the adhesive binder.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

(27) FIG. 1 illustrates the installed situation of an adhesive binder 1 for intermittently applying a flowable adhesive to substrates, in the present case to book spines 2 of book blocks 3. The adhesive is, for example, polyurethane. This hot melt adhesive has a particularly high resistance to the sheets being pulled out, and moreover an optimum lay-flat behavior for book blocks 3.

(28) With reference to the view in FIGS. 1 and 2, with respect to the device 1, a pre-melter 4, a feed line 5 for the heated adhesive, a return line 6 for the heated adhesive, and an application station 7 for the heated adhesive are shown. The book blocks 3 are clamped in transport clamps 8 and are moved by a conveying device 9 in a direction of movement which corresponds to the illustrated coordinates X of an orthogonal system, over the application station 7, and to be precise an applicator nozzle 10 of the application station 7. The other coordinates Y and Z are illustrated. A rectangular outlet cross-section of the applicator nozzle 10, viewed in the plan view, in an opposite direction to the coordinate Z, has an adjustable longitudinal extent in the direction Y, and a constant widthwise extent in the direction X. The variable longitudinal extent of the outlet cross-section is matched to the respective width of the book block 3, wherein this width extends in the direction Y, and the applied length of the adhesive on the book spine 2 of the book block 3 results from the conveying movement of the respective book block 3 in the direction X when the applicator nozzle 10 is open. Depending on the conveying speed of the book spine 2 relative to the open applicator nozzle 10 and on the mass flow rate of the adhesive through the outlet cross-section of the applicator nozzle 10, a defined application thickness in the direction Z results on the book spines 2 (see in particular the view in FIG. 3).

(29) The adhesive is applied uniformly to the book spines 2 with the aid of a control device 12, an electric drive means 13, and a pump 14, which can be driven by means of the drive means 13, for conveying the flowable adhesive. The speed of the drive means 13 can be regulated. The pump 14 is a geared pump. The drive means 13 and the pump 14 are arranged underneath the pre-melter 4. The drive means 13 is connected to the pump 14 via a clutch.

(30) The respective transport clamp 8 has a front jaw 15 in the form of a plate and a rear jaw 16 also in the form of a plate. The jaws 15, 16 of the respective transport clamp 8 are moved synchronously in the direction X. The respective rear jaw 16 cannot move in the direction Y. Only the front jaw 15 can move in the direction Y and in the opposite direction such that the distance between the two jaws 15, 16 can be modified in order to clamp the book blocks 3 between the jaws 15, 16. The respective rear jaw 16 forms, on the side facing the front jaw 15, a plane spanned by the coordinates X and Z which essentially lies on the same plane, apart from slight deviations, as a bearing surface 17 of a fixed feed guide 18 of the application station 7. This feed guide 18 forms a guide for the book block 3 on an applicator head 19 of the application station 7.

(31) Actively connected to the control device 12 are a sensor 20 for detecting the transport speed of the book block 3 in the direction X, a sensor 21 for detecting the beginning and end of the respective book block 3, relative to the direction X, and an actuator 22, in the form of a valve, for feeding the flowable adhesive to the applicator head 19 and, if required, a pressure sensor 23 via a connection line 24. The flowable adhesive is fed from the pre-melter 4 via the feed line 5 by positive displacement from the pump 14, which is driven by means of the drive means 13, and controlled via the control device 12. Adhesive conveyed by the pump 14 is returned to the pre-melter 4 via the return line 6 during periods when no adhesive is being applied.

(32) FIG. 3 shows a schematic diagram of a book block 3 and its most important dimensions, and moreover an application of adhesive 29. The adhesive is applied to the book spine 2. The application thickness 30 of adhesive can be set within a range of 0.05 to 4 mm. The application thickness preferably lies within the range of 0.3 to 0.6 mm for PUR. The distance from the beginning of the application 31 to the front side 32 of the book block 3 and the distance from the end of the application 33 to the rear side 34 of the book block 3 can be set to be between −5 and 100 mm. These values preferably lie between 0 and 15 mm. The application width, i.e. the dimension in the direction Y, corresponds essentially to the book block thickness and lies within the range of 1 to 80 mm. The maximum production rate of the book block 3 to be expected can be set to be between 1000 per hour and approximately 6000 per hour. The system described can, however, also be used for significantly higher production rates. The change in the application width is then restricted by adjusting the slide valve 26 between two successive book blocks.

(33) FIGS. 4 to 7 illustrate details of the applicator head 19 with an adjusting mechanism 25 for adjusting the outlet cross-section of the applicator nozzle 10. A cover, which takes the form of a slide valve 26, covers the outlet cross-section to a greater or lesser degree. The slide valve 26 can be displaced in the direction Y and in the opposite direction by means of the adjusting mechanism 25. The respective book block 3 is moved linearly in the direction X over the applicator nozzle 10 in the form of a slotted nozzle. The flowable adhesive is thus transferred onto the book spine 2 via the outlet cross-section. The respective slide valve 26 is guided, with as little play as possible, by a linear guide 27 and is activated via the adjusting mechanism 25, which is driven by a drive means 28, and is in each case adjusted such that the length Y of the outlet cross-section corresponds essentially to the book block thickness.

(34) The specific structure of the applicator nozzle 10 in the form of a slotted nozzle is shown in FIGS. 8 to 19 for a first exemplary embodiment.

(35) The applicator nozzle 10 has a stationary nozzle body 36. The latter has an inlet opening 37, a flow duct 38, and a nozzle slot 39. When the adhesive is conveyed through the applicator nozzle 10, the flowable adhesive passes from the inlet opening 37 into the flow duct 38 and from there to the nozzle slot 39. The flowable adhesive is discharged through an outlet opening 40 of the nozzle slot, which opening defines the outlet cross-section. The outlet opening 40 is arranged in an outer region of the nozzle body 36. The applicator nozzle 10 moreover has the slide valve 26, which is in the form of a plate, and can be moved relative to the nozzle body 36 in the longitudinal extent of the outlet opening 40, over the latter, by means of the adjusting mechanism 25 and contacts the outer region of the nozzle body 36, in order to change the extent to which the outlet opening 40 is covered. In particular, the slide valve 26 is pushed, under the action of a spring force, against the nozzle body 36 in order to optimally seal the outlet opening 40 in its region covered in each case by the slide valve 26.

(36) The nozzle body 36 is designed such that the longitudinal extent LS of the flow duct 38 is at least as great as the longitudinal extent LD of the nozzle slot 39. In the exemplary embodiment, the value LS is slightly greater than the value LD. The inlet opening 37 is hereby in fluid communication with the flow duct in the region of one end 41 of the flow duct 38. The other end 42 of the flow duct ends in the region of one end 43 of the nozzle slot 39. The outlet opening 40 can be covered by means of the slide valve 26, starting from the other end 44 of the nozzle slot 39. In the region of the nozzle slot 39, the flow duct 38 has a cross-sectional area which changes continuously over the local length of the flow duct 38, wherein the larger cross-sectional area faces the inlet opening 37.

(37) The flow duct 38 and the nozzle slot 39 each have a volume which does not change.

(38) In detail, in the region of the nozzle slot, the flow duct 38 has a cross-sectional area which changes continuously over the local length of the flow duct 38. It must not change linearly and will normally be a curve of single curvature. This cross-sectional area of the flow duct 38 decreases toward the end 42 of the flow duct. The shape of the changing cross-sectional area of the flow duct is hereby identical. The cross-sectional area of the flow duct 38 has a semi-circular shape.

(39) Over its length, the nozzle slot 39 has a shape such that the width BD of the nozzle slot 39 between the flow duct 38 and the outlet opening 40 of the nozzle slot 39 is constant. The depth (extent in the direction Z) of the nozzle slot 39 decreases from the other end 44 to the first end 43. This depth can change along a curve of single curvature.

(40) The outlet opening 40 and the nozzle slot 39 are arranged horizontally, and the flow duct 38 is arranged so that it is slightly inclined with respect to the horizontal.

(41) The nozzle body 36 has two strip-like nozzle body parts 45, 46. The latter are rigidly connected to each other by means of screws 47 which pass through the nozzle body part 45 and are screwed into threaded bores 53 of the nozzle body part 46. The flow duct 38 and the nozzle slot 39 are formed between the two nozzle body parts 45 and 46. The flow duct 38 and the nozzle slot 39 are formed exclusively by depressions in the nozzle body part 45. Furthermore, the facing surfaces of the two nozzle body parts 45, 46 are designed so that they are flat such that, in the interconnected state, the nozzle body parts 45, 46 lie tight against each other in the region of these flat surfaces. A feed line to the inlet opening 37, this feed line being configured as an angled duct 48, is formed in the nozzle body part 46. The angled duct 48 opens into the flow duct 38 in the region of the end 41 of the flow duct 38 in a region remote from the outlet opening 40 of the nozzle slot 39.

(42) The bearing surface 17 of the feed guide 18 is arranged perpendicularly to the longitudinal extent of the outlet opening 40, to the side of the outlet opening 40. On its side facing the fed guide 18, the slide valve 26 has a bearing surface 49 which in a central region is parallel to a central region of the bearing surface 17 of the feed guide 18. This respective central region is connected at the sides to insertion and exit slopes of the bearing surfaces 17 and 49. The feed guide 18 and the slide valve 26 hence serve to guide the book block 3 when it is conveyed over the nozzle body 36. The insertion of the book block 3 is facilitated by virtue of the converging insertion surfaces—bearing surfaces 17, 49.

(43) The nozzle body part 46 is provided in the region of its remote end sides with stepped bores 50 for receiving screws 51 which can be screwed into threaded bores of a base 52 of the applicator head 19, for fastening the stationary nozzle body 36.

(44) The specific structure of the applicator nozzle 10 in the form of a slotted nozzle is shown in FIGS. 20 to 24 for a second exemplary embodiment. Reference should be made hereby with respect to the first exemplary embodiment to the embodiments in their entirety relating to FIGS. 1 to 15. The second exemplary embodiment according to FIGS. 20 to 24 differs only in the modified geometry of the flow duct 38 and the nozzle slot 39. It can be seen in FIGS. 20 to 24 that the flow duct 38 has, in the region of the nozzle slot, a cross-sectional area which changes continuously over the local length of the flow duct 38. The change must not be linear and will normally be a curve of single curvature. This cross-sectional area of the flow duct 38 decreases toward the end 42 of the flow duct. The shape of the changing cross-sectional area of the flow duct 38 is hereby identical. The cross-sectional area of the flow duct 38 has a semi-circular shape. The cross-sectional area of the flow duct 38 at the other end 42 of the flow duct 38 is no more than half as large as the cross-sectional area of the flow duct 38 at the first end 41.

(45) Over its length, the nozzle slot 39 has a shape such that the depth (extent in the direction Z) of the nozzle slot 39 is constant between the ends 43 and 44. The width BD of the nozzle slot 39, and hence the extent of the nozzle slot 39 in the direction X, increases from the other end 44 toward the first end 43. This width can change along a curve of single curvature. This width is, for example, 0.32 mm in the plane of section XXI-XXI, 0.35 mm in the plane of section XXII-XXII, 0.4 mm in the plane of section XXIII-XXIII, and 0.53 mm in the plane of section XXIV-XXIV, with a constant depth of the nozzle slot of 1 mm over its length.

(46) FIG. 25 shows the basic design of the adhesive binder 1. The transport clamps 8 of the adhesive binder are fastened to the pulling means 9 and are moved in the direction X at a defined speed. This speed generally remains constant during production. The book blocks 3 are clamped in the transport clamps 8 and moved together with the transport clamps 8. The speed of the book blocks 3 is detected by the sensor 20 and forwarded to the control device 12 for processing. The book front edge associated with the front side 32 and the book rear edge associated with the rear side 34 are detected by the sensor 21 and forwarded to the control device 12 for processing. The adhesive binder transmits the signals for the book block thickness in a suitable fashion to the control device 12 such that the latter can associate the book block thicknesses to be processed explicitly with the book blocks to be processed. The important thing here is that the control device 12 has the data for the speed and the book block thickness and can determine the time at which each application of adhesive starts and finishes. The manner in which the data required for this pass to the control device 12 can also take a different form to the one which has been shown or described.

(47) The adhesive is held ready in the pre-melter 4 in molten and flowable form. The pump 14 delivers the adhesive held ready in the pre-melter 4 via the feed line 5 and the actuator 22 or valve either to the applicator nozzle 10, during the application of adhesive to the book spines 2, or via the return line 6 back to the pre-melter 4. The pressure of the adhesive is detected by the optional pressure sensor 23 directly upstream from the actuator 22 and transmitted to the control device 12. The pressure sensor 23 is not strictly necessary for satisfactory functioning of the system and can be omitted for cost reasons or only installed temporarily.

(48) The slide valve 26 of the applicator nozzle 10 for adjusting the application width of adhesive is activated, adjusted, and set via the adjusting mechanism 25 and the drive means 28. The signal and the triggering of the drive means 28 can either be provided or take place by the control device of the adhesive binder or by the control device 12 of the device 1. The actuator 22 for feeding the adhesive to the applicator nozzle 10 is activated by the control device 12 in such a way that the beginning of each adhesive application and the end of each adhesive application correspond precisely to the previously determined values. The actuator 22 takes the form of a switching valve. In a first position of the actuator 22, the flow from the feed line 5 to the applicator nozzle 10 is free and the return line 6 is blocked. In a second position of the actuator 22, the feed of the adhesive to the applicator nozzle 10 is interrupted and the feed line 5 is connected to the return line 6 via a choke 35 integrated into the actuator 22. Instead of this choke being integrated into actuator 22, this choke or a choke element can also be installed in the return line 6 as a separate component. When the feed of adhesive to the applicator nozzle 10 is interrupted by means of the actuator 22, if required because the thickness of the book block has changed, the slide valve 26 is displaced to match the new book block thickness.

(49) The drive means 13 of the pump 14 is triggered with the aid of all the above described signals by the control device 12 in such a way that the application of adhesive to the book blocks 3 has a well-defined start, a well-defined end, and a uniform distribution over the length of the application. This is effected by the adhesive being delivered by means of the pump 14 working essentially in a positive displacement fashion. The theoretical volume flow of adhesive during the application is determined from the speed of the book blocks 3 being moved, from the application width, and from the application thickness of the adhesive on the book block 3. The application thickness must be fed to the control device 12 as a parameter. This is generally effected via an input terminal which is operated by the user of the device 1. As part of digital book production, the predefined value for the application thickness can also be fed to the control device 12 by the adhesive binder or from a higher-level control system. It is likewise conceivable for the signal for the book block thickness to be fed to the control device 12 from a higher-level control system. Whilst the application of adhesive to the book blocks 3 is interrupted and the actuator 22 is switched to recycle adhesive to the pre-melter 4, the pump 14 generally delivers a volume flow of adhesive which differs from the volume flow of adhesive of the applied adhesive. This volume flow of adhesive during the recycling to the pre-melter 4, i.e. during the circulation of adhesive, is of a magnitude such that the pressure of adhesive upstream from the actuator 22 is as uniform as possible, as it is during the application of adhesive to the book spines 2 via the applicator nozzle 10.