PRODUCTION MACHINE FOR PRODUCING ROD-SHAPED PRODUCTS FROM AN END-LESS STRAND OF A STRIP ADHESIVELY BONDED TO FORM A TUBE

Abstract

The invention relates to a production machine for producing rod-shaped products from a continuous strand of a continuous strip adhesively bonded to form a tube, comprising a device for applying a glue track to a strip, a format portion, in which the continuous strip into the continuous strand by shaping and adhesive bonding, and a cutting device which cuts the rod-shaped products from the continuous strand at a predetermined length, wherein the device for applying the glue track is formed by a device which applies the glue intermittently to form glue-free portions arranged at regular intervals, and a sensor apparatus is provided, which is directed towards the continuous strip or the continuous strand and generates a signal depending on the passage of a glue-free portion, and the device for applying the glue track is designed to change the length of the glue-free portions in the longitudinal direction of the glue track.

Claims

1. A production machine for producing rod-shaped products from a continuous strand of a continuous strip adhesively bonded to form a tube, comprising: a device for applying a glue track to a strip, a format portion, in which the continuous strip can be formed into the continuous strand by shaping and adhesive bonding, and a cutting device which cuts the rod-shaped products from the continuous strand at a predetermined length, wherein the device for applying the glue track is formed by a device which applies the glue intermittently to form glue-free portions arranged at, in particular regular, intervals, and a sensor apparatus is provided, which is directed towards the continuous strip or the continuous strand and generates a signal depending on the passage of a glue-free portion, and the device for applying the glue track is designed to adjust and/or change the length of the glue-free portions in the longitudinal direction of the glue track.

2. the production machine according to claim 1, wherein the device for applying the glue track has a controller for adjusting and/or changing the duration of the interruption of the glue application.

3. The production machine according to either claim 1, wherein the device for applying the glue track has a nozzle, the distance of which from the glue track to be applied can be changed.

4. The production machine according to claim 3, wherein the device for applying the glue track has a rotationally driven roller, to which the nozzle applies the glue track and which further applies the glue track to the continuous strip.

5. The production machine according to claim 4, wherein the nozzle has an edge portion delimiting the outlet opening and protruding in the direction of the roller, which edge portion is arranged on the edge of the outlet opening that is arranged downstream with respect to the direction of rotation of the roller.

6. The production machine according claim 4, wherein the nozzle is arranged such that the centre of the outlet opening is eccentric to the axis of rotation of the roller, counter to the direction of rotation of the roller.

7. The production machine according to claim 4, wherein the roller is provided so as to be rotationally drivable in the opposite direction with respect to a transport direction of the continuous strip.

8. The production machine according to claim 4, wherein the glue has a viscosity greater than 230 mPas.

9. The production machine according to claim 1, wherein the sensor apparatus is arranged between the format portion and the cutting device.

10. The production machine according to claim 9, wherein the sensor apparatus is a high-frequency sensor apparatus.

11. The production machine according to claim 1, wherein the sensor apparatus is arranged between the device for applying the glue track and the format portion.

12. A method for operating a production machine according to claim 1, wherein the device for applying the glue track is controlled depending on the signal from the sensor apparatus in order to adjust and/or change the length of the glue-free portions.

13. The method according to claim 12, wherein the length of the glue-free portions can be adjusted and/or changed by adjusting and/or changing the duration of the interruption of the glue application and/or by adjusting and/or changing the distance of the device for applying the glue track on the strip, and/or wherein the production machine is designed such that the device for applying the glue track has a rotationally driven roller, to which the nozzle applies the glue track and which further applies the glue track to the continuous strip, and the adjustment and/or the change of the length of the glue-free portions is controlled by changing the speed of the roller.

14. The method according to claim 12, wherein the strip is transported at a transport speed of more than 100 m/min.

15. A rod-shaped product cut from a continuous strand of a continuous strip adhesively bonded to form a tube, wherein the strip is adhesively bonded to form the tube using an adhesive seam interrupted by glue-free portions, and the product is cut from the strand by a cut through one of the glue-free portions.

16. The rod-shaped product according to claim 15, wherein the adhesive seam is formed from a highly viscous glue having a viscosity of more than 230 mPas.

17. The rod-shaped product according to claim 15, wherein the product is made of a food-grade material.

18. The rod-shaped product according to claim 17, wherein the product is a drinking straw.

19. The production machine according to claim 1, wherein the device for applying the glue track applies the glue intermittently to form glue-free portions arranged at regular intervals.

20. The rod-shaped product according to claim 15, wherein the glue has a viscosity greater than 1,000 mPas.

Description

[0028] The invention will be explained below on the basis of preferred embodiments with reference to the accompanying drawings, in which:

[0029] FIG. 1 is a schematic view of a device according to the invention, and

[0030] FIG. 2 shows an enlarged detail of the device with a view of the strand, and

[0031] FIG. 3 is an enlarged sectional view of the device for applying the glue.

[0032] FIG. 1 is a schematic view of the production machine 1 according to the invention, to which a continuous strip 2, for example in the form of a paper strip, is supplied. The strip 2 is guided past a device 15 for applying a glue track 13, which can only be seen in FIGS. 2 and 3. After the glue track 13 has been applied, the strip 2 is introduced into a format portion 10 in which the edges of the strip 2 are turned up, placed on top of one another and finally connected to one another via the glue track 13 to form an adhesive seam and fixed in shape to form a continuous tubular strand 9. The format portion 10 is followed by a drying section 11 which can be provided with additional drying units, for example heat sources. Depending on the nature of the glue and the transport speed of the strand 9, the drying section 11 is designed in such a way that, after exiting the drying section 11, the adhesive seam is dried to such an extent that it can then no longer be released. After exiting the drying section 11, the shape-fixed, tubular strand is guided past a cutting device 4 which cuts rod-shaped products 3 from the strand 9 at a predetermined length. The cutting device 4 comprises a rotating blade carrier having one or more radially projecting blades 8 which cut through the strand 9 at defined time intervals due to the rotary movement of the blade carrier and thereby cut the products 3 from the strand 9 at a predetermined length, taking into account the transport speed of the strand 9. Such products 3 can be, for example, drinking straws, prefabricated products 3 from the tobacco processing industry or prefabricated products 3 from “heat-not-burn” products or electronic cigarette products. In this respect, the production machine 1 corresponds to a production machine 1 known in the prior art.

[0033] The production machine 1 according to the invention differs from the prior art in that the device 15 for applying the glue track 13 is designed as an intermittent application device, and in that at least one sensor apparatus 7 is additionally provided, which, as will be explained in more detail below, is directed towards the strip 2 or the strand 9.

[0034] The strip 2 with the device 15 for applying the glue track 13 can be seen from above in FIG. 2. The device 15 applies the glue track 13 to the edge of the strip 2 intermittently, i.e. to form glue-free portions 14 of a predetermined length. The strip 2 is then folded over and adhesively bonded to form the tubular strand 9, the glue track 13 with the glue-free portions 14 connecting the two edges of the strip 2 in the tubular strand 9 to one another by means of a regularly interrupted adhesive seam.

[0035] The device 15 can apply the glue track 13 in different widths, up to a glue application over the entire surface of the strip 2, depending on how the adhesive bonding of the strip 2 to form the tubular strand 9 is to be implemented. A plurality of strips 2 can also be adhesively bonded in multiple layers to form a strand 9. Furthermore, a sensor apparatus 7 is provided, which is either arranged between the format portion 10 and the device 15 for applying the glue track 13 and is directed towards the edge of the strip 2 provided with the glue track 13, or is alternatively arranged between the format portion 10 and the cutting device 4 and is directed towards the adhesive seam in the strand 9. The sensor apparatus 7 is designed in such a way that it generates a signal which is dependent on the passage of a glue-free portion 14 in the glue track 13 or in the adhesive seam and allows the length of the glue-free portion 14 to be inferred. Furthermore, the sensor apparatus 7 is in a fixed spatial association with the cutting device 4, such that, taking into account the transport speed of the strip 2 or the strand 9, it is also possible to infer when the detected glue-free portions 14 pass the cutting device 4.

[0036] As can be seen in FIG. 1, a control unit 12 is also provided on the production machine 1, to which the signals from the sensor apparatus 7 are supplied. In addition, the control unit 12 is also connected in terms of signalling to the device 15 for applying the glue track 13 and the cutting device 4 and to a drive apparatus (not shown) of the strip 2 or the strand 9. The control unit 12 can also comprise a display apparatus and an input unit, which allow the display of the determined parameters and the input of corresponding control commands.

[0037] The operator can adjust the production machine 1 in a one-off adjustment process or an adjustment process which is to be repeated regularly. In this case the operator can recognize the point in time at which the glue-free portions 14 pass the cutting device 4 using the signals determined by the sensor apparatus 7, which are indicated by means of an evaluation taking into account the transport speed. The operator then adjusts the production machine 1 in such a way that the glue-free portions 14 pass the cutting device 4 precisely when the cutting device 4 cuts through the strand 9 with the blade 8. In another embodiment, the adjustment can also be made online in a fully automated closed-loop control process, i.e. during operation of the production machine 1, such that manual intervention or manual control is not required to trigger the adjustment process. The length and position of the glue-free portions 14 in the glue track 13 are adjusted by controlling the device 15, as will be explained in more detail below.

[0038] FIG. 3 is an enlarged view of a section through the device 15 for applying the glue track 13 with the strip 2 guided past said device. The device 15 comprises a nozzle 5 having an outlet opening 17, from which the glue emerges, and a roller 6 which is rotationally driven to rotate in the direction of the arrow and onto which the glue discharging from the outlet opening 17 is applied in the form of a glue track 13. This glue track 13 is then applied or rubbed onto the edge of the strip 2 by the roller 6. The roller 6 is driven counter-clockwise in the illustration, while the strip 2 is moved vertically downwards. This results in opposite movements of the strip 2 and the roller 6 on the right-hand edge of the roller, i.e. on the edge of the roller 6 along which the strip 2 is guided. The relative speed between the strip 2 and the circumferential surface of the roller 6 thus results from the sum of the transport speed of the strip 2 and the circumferential speed of the roller 6, and the glue is applied to the strip 2 with a correspondingly increased relative speed.

[0039] In order to control the lengths and positions of the glue-free portions 14 in the glue track 13, the intermittent device 15 can be controlled in such a way that the duration of the interruption in the glue supply and the start and end of the interruption in the glue supply are changed, while the remaining parameters remain constant.

[0040] The nozzle 5 is arranged such that the centre of the outlet opening 17 is eccentrically offset by the dimension E with respect to the axis of rotation of the roller 6 upstream of the rotational movement of the opposite circumferential surface of the roller 6, i.e. counter to the transport direction of the strip 2. Furthermore, the nozzle 5 has, on the edge 18 thereof which is the lower edge in the illustration, i.e. arranged downstream with respect to the circumferential movement of the roller 6, an edge portion 16 protruding in the direction of the roller 6, by means of which the distance A between the edge 18 of the outlet opening 17 and the roller 6 is reduced and a constriction is formed. By means of this constriction, the glue is applied to the circumferential surface of the roller 6 in a glue track 13 with a correspondingly reduced thickness and is removed by the roller 6 before it is applied to the strip 2 as a glue track 13.

[0041] Due to the reduced distance A, the glue discharging from the outlet opening 17 is accumulated in a glue reservoir 19 before it is removed via the constriction. This deliberately formed glue reservoir 19, in combination with the intermittent glue supply through the nozzle 6, has the advantage that the length of the glue-free portions 14, in particular when using highly viscous glues having a viscosity of 230 mPas and in particular of 1,000 mPas and more, can be reduced to a length of 4 mm and less, which would otherwise not be possible at the high transport speed of the strip 2 with such a highly viscous glue. This is achieved by the glue reservoir 19 first being deliberately constructed during the glue supply. From the point at which the glue supply is interrupted, the glue then continues to be applied from the glue reservoir 19 to the roller 6 and via the roller to the strip 2 until the glue reservoir 19 is also emptied. Only then does the application of glue to the strip 2 end, such that the temporal and spatial start of the glue-free portion 14 on the strip 2 can be deliberately delayed further with respect to the interruption of the glue supply. This time delay in turn depends on the volume of the glue reservoir 19, which in turn can be changed by reducing or increasing the distance A. Since the roller 6 is mounted in a stationary manner with the axis of rotation thereof and the strip 2 is arranged at a constant distance from or in constant contact with the strip, there is also a change in the distance between the nozzle 5 and the strip 2. If the glue track 13 is applied directly to the strip 2 by the nozzle 5, the start and the length of the glue-free portions 14 can also be achieved in the same way by forming and changing the glue reservoir 19, which is formed directly between the nozzle 5 and the strip 2.

[0042] The volume of the glue reservoir 19 and thus the time delay in the interruption of the glue application can be controlled by the glue reservoir 19 being accumulated to a greater volume by reducing the distance A. Alternatively or additionally, the volume of the glue reservoir 19 and the glue application, and thus the length of the glue-free portions 14, can be controlled directly by changing the speed of the roller 6.

[0043] Controlling the length of the glue-free portions 14 by changing the distance A between the nozzle 5 and the roller 6 in particular has the advantage that the length of the glue-free portions 14 can be reduced to lengths of less than 4 mm, in particular to 2-3 mm, thereby, which at the high transport speeds of the strip of 100 m/min and more, in particular more than 400 m/min, is not possible solely by controlling the temporal interruption for mechanical reasons, due to the inertia of the closing mechanism in the intermittent device 15.

[0044] However, a glue application via the shown roller 6 has the additional advantage that the nozzle 5 does not or cannot come into contact with the strip 2 and therefore is not subject to closure. This is particularly advantageous because the nozzle 5 is a comparatively expensive component, and the costs for maintaining the production machine 1 can therefore be reduced since the required replacement intervals for the nozzle 5 can be lengthened considerably.

[0045] Furthermore, the application of glue via the roller 6 also makes a clean application of glue to very porous papers possible, and undesired penetration of the glue through the paper can in particular be prevented. Furthermore, the glue is applied by the nozzle 5 to the roller 6 in a contactless manner, such that, in terms of height and width, any amount of glue can be applied to the roller 6 and then further applied by the roller 6 to the strip 2. For example, an amount of glue of 150 g/500 m can be applied to the strip 2, which is not possible with the desired quality by a direct glue application via the nozzle 5 to the strip 2.

[0046] Furthermore, the application of the glue track 13 with the glue-free portions 14 counteracts the tendency for glue drips to form on the nozzle 5, since the nozzle 5 is practically “cleaned” at the outlet opening thereof at regular time intervals, due to the regular interruption of the glue supply as a result of the glue reservoir 19 “emptying”.

[0047] The glue track 13 can be very narrow and applied to one of the edges, such that the products 3 are only adhesively bonded by a very narrow adhesive seam in a thin edge portion of the overlapping edges. If a stronger adhesive seam or a stiffer product 3 is to be produced, the glue track 13 can also be applied so as to be wider up to the entire width, i.e. in an application over the entire surface, and the products 3 can in this case be fixed in shape by placing the edges on top of one another and adhesively bonding same with wider edge portions to provide greater dimensional stability with a smaller diameter.