Method and system for splicing two sheets of material containing alkaloids

Abstract

A method for splicing two sheets of material containing alkaloids is provided, the method including: providing a first sheet of material containing alkaloids wound in a first bobbin; providing a second sheet of material containing alkaloids wound in a second bobbin; unwinding the first sheet wound in the first bobbin; evaluating one or more of the following parameters of the unwound first sheet: moisture, thickness, width, stickiness, and presence or absence of holes or tears; and depending on a value of the evaluated one or more parameters, unwinding the second sheet wound in the second bobbin, and splicing the first sheet and the second sheet. A system for splicing two sheets of material containing alkaloids is also provided.

Claims

1. A method for splicing two sheets of material containing alkaloids, the method comprising: providing a first sheet of material containing alkaloids wound in a first bobbin; providing a second sheet of material containing alkaloids wound in a second bobbin; unwinding the first sheet of material containing alkaloids wound in the first bobbin; evaluating one or more of the following parameters of the unwound first sheet of material containing alkaloids: moisture of the first sheet of material containing alkaloids, thickness of the first sheet of material containing alkaloids, width of the first sheet of material containing alkaloids, stickiness of the first sheet of material containing alkaloids, and presence or absence of holes or tears in the first sheet of material containing alkaloids; and depending on a value of the evaluated one or more parameters, unwinding the second sheet of material containing alkaloids wound in the second bobbin, and splicing the first sheet of material containing alkaloids and the second sheet of material containing alkaloids.

2. The method according to claim 1, further comprising rejecting the first bobbin after the splicing.

3. The method according to claim 1, further comprising buffering a given length of the first sheet of material containing alkaloids before the splicing.

4. The method according to claim 1, further comprising: capturing an image of the first sheet of material containing alkaloids; and determining, from the image, a width of the first sheet of material containing alkaloids or a presence or absence of holes or tears in the first sheet of material containing alkaloids.

5. The method according to claim 1, further comprising: impinging a light beam onto the first sheet of material containing alkaloids; and determining a width or a thickness of the first sheet of material containing alkaloids or a presence or absence of holes or tears in the first sheet of material containing alkaloids from a characteristic of the light beam transmitted through the first sheet of material containing alkaloids.

6. The method according to claim 1, further comprising: measuring a distance between the first sheet of material containing alkaloids and a first sensor; and determining, from the measured distance, a stickiness of the first sheet of material containing alkaloids.

7. The method according to claim 1, further comprising: measuring a force needed to unwind the first sheet of material containing alkaloids from the first bobbin; and determining, from the measured force, a stickiness of the first sheet of material containing alkaloids.

8. The method according to claim 1, further comprising interchanging a position of the first bobbin and a position of the second bobbin after the splicing.

9. A system for splicing two sheets of material containing alkaloids, the system comprising: a first shaft configured to hold, in a rotatable manner, a first bobbin of a first sheet of material containing alkaloids; a second shaft configured to hold, in a rotatable manner, a second bobbin of a second sheet of material containing alkaloids; one or more of the following first sheet sensors: a moisture sensor configured to measure a moisture of the first sheet of material containing alkaloids and to emit a signal on the basis of the moisture measurement, a thickness sensor configured to measure a thickness of the first sheet of material containing alkaloids and to emit a signal on the basis of the thickness measurement, a width sensor configured to measure a width of the first sheet of material containing alkaloids and to emit a signal on the basis of the width measurement, a stickiness sensor configured to measure a stickiness of the first sheet of material containing alkaloids and to emit a signal on the basis of the stickiness measurement, and an optical sensor or a sound sensor configured to detect a presence or absence of holes or tears in the first sheet of material containing alkaloids; a splicing unit configured to splice the first sheet of material containing alkaloids and the second sheet of material containing alkaloids, the splicing unit being located downstream of the one or more first sheet sensors; and a controller connected to the one or more sensors and to the splicing unit, and being configured to activate the splicing unit to splice the first sheet of material containing alkaloids and the second sheet of material containing alkaloids on the basis of the signal emitted by the one or more first sheet sensors.

10. The system according to claim 9, further comprising one or more of the following second sheet sensors: a moisture sensor configured to measure a moisture of the second sheet of material containing alkaloids and to emit a signal on the basis of the moisture measurement, a thickness sensor configured to measure a thickness of the second sheet of material containing alkaloids and to emit a signal on the basis of the thickness measurement, a width sensor configured to measure a width of the second sheet of material containing alkaloids and to emit a signal on the basis of the width measurement, a stickiness sensor configured to measure a stickiness of the second sheet of material containing alkaloids and to emit a signal on the basis of the stickiness measurement, and an optical sensor or a sound sensor configured to detect a presence or absence of holes or tears in the second sheet of material containing alkaloids.

11. The system according to claim 9, wherein the stickiness sensor is a distance sensor or a force sensor.

12. The system according to claim 9, wherein the width sensor is an optical sensor including a light source.

13. The system according to claim 9, further comprising a bobbin holder comprising the first shaft and the second shaft, the bobbin holder being configured to interchange a position of the first shaft and the second shaft.

14. The system according to claim 9, further comprising a buffer configured to buffer a variable amount of the first sheet of material containing alkaloids or of the second sheet of material containing alkaloids, the buffer being located downstream of the splicing unit.

Description

(1) Examples will now be further described with reference to the figures in which:

(2) FIG. 1 is a schematic lateral view of a system to splice a first sheet and a second sheet according to the invention;

(3) FIG. 2 is a schematic top view of a first sheet and a second sheet spliced by the system of FIG. 1;

(4) FIG. 3 and FIG. 4 are two schematic lateral view of two operative positions of the system of FIG. 1;

(5) FIG. 5 is a lateral view of a first sheet presenting a defect;

(6) FIG. 6 and FIG. 7 are two lateral views of a detail of an embodiment of the system of FIG. 1;

(7) FIG. 8 is a more detailed lateral view of a portion of the system of FIG. 1;

(8) FIG. 9 is a more detailed view of another portion of the system of FIG. 1;

(9) FIG. 10 is a top view of a first sheet;

(10) FIG. 11 is a top view of the first sheet of FIG. 10 in a phase of the method of the invention;

(11) FIG. 12 is a top view of a second sheet;

(12) FIG. 13 is a top view of the second sheet of FIG. 12 in a phase of the method of the invention;

(13) FIG. 14 is a top view of a processed first sheet of FIGS. 10 and 11 in a further step of the invention;

(14) FIG. 15 is a top view of a processed second sheet of FIGS. 12 and 13 in a further step of the invention;

(15) FIG. 16 is a top view of a further steps of the invention of the splicing of the first and the second sheet of FIGS. 14 and 15; and

(16) FIGS. 17 and 18 are top views of two further steps of the method of the invention applied to the spliced sheet of FIG. 16.

(17) With initial reference to FIGS. 1 and 8, a system to splice a first sheet and a second sheet of material containing alkaloids is globally indicated with 1.

(18) The system 1 comprises a first shaft 41 and a second shaft 31, on which a first bobbin 40 and a second bobbin 30 are respectfully inserted. The first shaft 41 and second shaft 31 are rotatable around their respective axis (not shown in the drawings). The first bobbin 40 supplies the first sheet of material 4 and the second bobbin 30 supplies the second sheet 3 of material. Preferably, the first sheet 4 and the second sheet 3 are homogenised tobacco sheets.

(19) In FIG. 8, the system 1 includes a rotatable bobbin holder 11. The rotatable bobbin holder 11 includes the first shaft 41 and the second shaft 31, extending from the bobbin holder 11. The bobbin holder 11 is thus provided with the two bobbins 30,40 carrying the two sheets 3,4.

(20) The system 1 further comprises a splicing unit 2, schematically indicated with a rectangle in FIGS. 1 and 8. The first sheet 4, which in FIGS. 1 and 8 is the sheet in use, is supplied to the splicing unit 2. The unwinding of the first sheet 4 from the first bobbin 40 and its supply to the splicing unit 2 takes place via guide pulley 22. The first sheet 4 is transported towards the splicing unit 2 and in the further processing stages along a transport direction which is indicated by the arrow 50.

(21) Downstream of the splicing unit 2, the system 1 comprises an acceleration unit in the form of two acceleration rollers 5 (visible in FIG. 8). The first sheet and second sheet (detailed below) being passed through the splicing unit 2 may be accelerated or slowed down by the acceleration unit 5. The first sheet 4 or second sheet 3 may be continuously accelerated upon passing between the two acceleration rollers 5 in order to secure a continuous velocity of the sheet. Preferably, for the splicing process, the sheet may be decelerated or stopped by the acceleration rollers 5. After a splicing process, the spliced sheet may be accelerated again to a process velocity.

(22) Downstream the acceleration rollers 5, the system 1 comprises a buffer system 6. The buffer system 6 comprises a plurality of rollers, all indicated with 7, such as a series of idler pulleys, where the first sheet 4 or the second sheet 3 is guided around and forms loops. Some of the idler pulleys 7 are arranged in a movable manner such as to enlarge or shorten a sheet loop in order to be able to further provide sheet material in a downstream direction, even when a supply from the splicing unit 2 or from the first bobbin 40 or second bobbin 30 is interrupted or reduced.

(23) Downstream of the buffer system 6 a pulling unit 8 (visible only in FIG. 8) pulls the first sheet 4 or the second sheet 3 out of the buffer system 6 to pass the sheet preferably at a constant velocity to further downstream arranged sheet processing units (not visible).

(24) Further elements and units may be included in the system 1, such as a crimper and a rod former (not shown in the drawings), both located downstream the buffer system 6 and pulling unit 8.

(25) Between the first shaft 41 and the splicing unit 2, along the path taken by the first sheet 4 along the transport direction 50, at least a first sheet sensor 9 is located in the system 1. Sensor 9 is schematically depicted as a rectangle in FIGS. 1 and 8. The sensor 9 may be a thickness sensor. The sensor 9 may be a width sensor. The sensor 9 may be a moisture sensor. The sensor 9 may be stickiness sensor. The sensor 9 may be a detector for the presence or absence of holes or tears in the first sheet 4.

(26) As example of first sheet sensor 9 is depicted in FIGS. 6 and 7. The sensor 9 is a stickiness sensor, comprising a distance sensor. In FIG. 6, the first sheet 4 is unwound from first bobbin 40. The first sheet defines a separation line 91 between the free end 92 of the first sheet which is already unwound from the first bobbin 40 and the remaining first sheet 93 still wound in the first bobbin 40. An angle 94 is formed between a vertical plane 95 passing through the rotational axis of the first shaft 41 and perpendicular to the same, and a plane 96 passing through the rotational axis of the first shaft 41 (and perpendicular to the same) and the separation line 91. With a given angle 94, the distance measured by sensor 9 has a given value. If the stickiness of the first sheet 4 changes, and in particular increases, the distance between sensor and sheet changes (as well as angle 94), as depicted in FIG. 7. In this way a change in stickiness of the first sheet 4 can be measured.

(27) Between the second shaft 31 and the splicing unit 2, along the path taken by the second sheet 3, at least a second sheet sensor 10 is located in the system 1, schematically depicted as a rectangle in FIGS. 1 and 8. The sensor 10 may be a thickness sensor. The sensor 10 may be a width sensor. The sensor 10 may be a moisture sensor. The sensor 10 may be stickiness sensor. The sensor 10 may be a detector for the presence or absence of holes or tears in the second sheet 3. First sheet sensor 9 and second sheet sensor 10 may be the same type of sensor. First sheet sensor 9 and second sheet sensor 10 may measure the same integrity parameter of the first sheet 4 and second sheet 3, respectively.

(28) System 1 further include a control unit 100. Control unit 100 is connected to first sheet sensor 9, second sheet sensor 10 and the splicing unit 2. Preferably, control unit is also connected to bobbin holder 11, buffer system 6, and acceleration unit 5 to command the same. Some of the connections are visible in the figures as dotted lines. Not all connections are depicted for clarity of the figures.

(29) With now reference to FIG. 9, the splicing unit 2 is shown in details. Sone parts of the system 1, such as the buffer system 6, are not shown in FIG. 9. Splicing unit 2 includes a cutting knife 20 to cut the first sheet 4 or the second sheet 3 or both. The splicing unit 2 further includes a dispensing unit 23 adapted to dispense water onto the first sheet 4 or second sheet 3. The splicing unit 2 also includes compressing rollers 24 to compress the spliced first sheet and second sheet. The splicing unit 2 comprises preferably also a heating unit 25, for example a hot air source or a heat radiating source, arranged downstream adjacent the compressing rollers 24.

(30) The functioning of the system 1 is as follow.

(31) In FIG. 1 the first tobacco sheet 4, unwound from the first bobbin 40, is in use and is passing in a substantially straight direction through the splicing unit 2. No processing takes place in the splicing unit. The first sheet 4 is then buffered for a given length in the buffer system 6 and it is further transported to sheet processing units arranged further downstream (not shown). Such processing units may for example be a crimping unit or a rod forming unit.

(32) While travelling towards the splicing unit 2, the sensor 9 evaluate one or more integrity parameters of the first sheet, at a given frequency, checking the surface of the first sheet while the first sheet travels along the transport direction 50. Signals representative of the integrity parameters are sent to the control unit 100 where they are elaborated, for example compared to a threshold.

(33) In this situation, the buffer system 6 is buffering a maximum length of the first sheet 4, as depicted in the configuration of the system 1 depicted in FIG. 3. The rollers 7 are distanced at the maximum distance one from the other. This distance can be along a horizontal direction (see FIG. 3) or a vertical direction (see FIG. 8).

(34) For example, the sensor 9 is a thickness sensor. The sensor 9 measures the thickness of the first sheet 4 at a given frequency. As shown in FIG. 5, where a section of the first sheet 4 is shown along a plane containing the transport direction 50, the sensor 9 measures a first thickness 81 in a first portion 42 of the first sheet 4 at a time t1. The thickness 82 is then compared by the control unit 100 with a threshold and it results within the acceptable range, such as in a green range. At a subsequent time t2, the first sheet 4 has moved and thus the sensor 9 can measure the thickness 82 of the first sheet 4 in a second portion 43. The thickness 82 is then compared by the control unit 100 with a threshold. For example, it is found that the results are not within the acceptable range, but not very far from the acceptable range. Then the control unit 100 considers the value to be in a yellow range. At a subsequent time t3, the first sheet 4 has moved again and the sensor 9 can measure the thickness 83 of the first sheet 4 in a third portion 44. The thickness 83 is then compared by the control unit 100 with a threshold. For example, it is found that the results are not within the acceptable range, that is, the value 83 is in a red range. This is considered to be a non-acceptable defect of the first sheet 4 and the control unit 100 commands the splicing unit 2 to start the splicing.

(35) The second sheet 3 from the second bobbin 30 is guided via guide pulley 22 and supplied to the splicing unit 2 (in FIG. 9, the second sheet 3 is supplied from below first sheet 4 in use). Both sheets 3,4 are arranged on top of each other and aligned on a support surface 21 of the splicing unit 2. They are then cut under a cutting angle by cutting knife 20 (depicted for example in FIG. 2). This operation is better detailed in FIG. 10 to FIG. 13. The first sheet 4 travelling along the transport direction 50 (see the top view of FIG. 10) is cut along a cut line 47, as shown in FIG. 11. The cut line forms an angle different from 0 degrees or 90 degrees with the transport direction. The second sheet 3 travelling along the transport direction 50 (see the top view of FIG. 12) is cut along a cut line 37, as shown in FIG. 13. The cut line forms an angle different from 0 degrees or 90 degrees with the transport direction. Cut lines 37 and 47 are preferably congruent when the first sheet and second sheet are overlapping. By the cut line 47, a clearly defined end portion 48 of the first sheet 4 and a waste portion 49 of the first sheet are defined, as shown in FIG. 14. By the cut line 37, a clearly defined waste portion 38 of the second sheet 3 and a head portion 39 of the second sheet 3 are defined, as shown in FIG. 15.

(36) The waste portion 49 of the first sheet 4 and the waste portion 38 of the second sheet 3 may be removed after cutting the sheets 3,4. While the cutting does not necessarily have to be performed with aligned sheets, the splicing process does. As can be seen in FIG. 16, the sheets 4, 3 that have been cut are then aligned above each other with their cutting lines 47, 37 to overlie each other. The cut line 47 in reality is not visible, however it is depicted in FIG. 16 as a dotted line to show the overlapping portion 36. In the overlapping portions, two surfaces 45, 35, belonging to the first sheet and second sheet, respectively, referred to as the cutting surfaces, are in contact to each other (shown in FIG. 17). While the cutting direction in FIG. 2 is inversed with respect to the cutting direction of the cutting knife 20 of FIG. 8, the splicing process is the same. The cutting angle is in both figures about 30 degrees.

(37) Water is dispensed onto the lower lying sheet 3 and onto the cutting face 35 by the dispensing unit 23. By a thin water layer (not visible in the drawings) applied to one sheet only, such as the second sheet 3, the water may soften the material of the sheets 3,4 at least in the area of the cutting surfaces 35, 45 to support a good interconnection of the sheets 3,4 in the overlapping area 36. However, the amount of water is small enough to not disintegrate the sheets.

(38) The so overlying and wetted sheets 3,4 are then guided through compressing rollers 24. The sheets are compressed upon passing between the compressing rollers, which securely fixes the two cutting surfaces 45,35 and the two sheets 3,4 to each other. The pressure applied by the compressing rollers 24 is indicated by an arrow 51 in FIG. 17. A short but firm connection is formed, as schematically shown in FIG. 18 or in FIG. 2. To support the joint formation, the heating unit 25 heats the combined sheets. By the heat, the connection is quickly dried such that the now spliced tobacco sheet may continue to be provided to further downstream arranged processing units.

(39) While the splicing takes place, due to the fact that the first sheet needs to be slowed down or stopped in order to perform the splicing, the first sheet 4 buffered in the buffer system 6 is used in the further processing steps. During the splicing therefore, the first sheet 4 in the buffer system 6 is used and the rollers 7 get closer to each other reaching a minimum distance, as depicted in FIG. 4.

(40) When the splicing is commanded by the control unit 100, before it has taken place, the first bobbin 40 is rotated in anti-clockwise direction (indicated by arrow in FIG. 8) by the bobbin holder 11 away from the splicing unit 2. Upon the same rotating movement, the second bobbin 30 has been moved closer to the splicing unit 2. The second tobacco sheet 3 from the second bobbin 30 is guided via guide pulley 22 into the splicing unit 2, where splicing may be performed. After cutting in the splicing unit, the then cut off first tobacco sheet 4 may be removed together with the first bobbin 40 from the first shaft 41 in the bobbin holder 11. It may be replaced by a new bobbin. As soon as the second bobbin 30 comes to an end, the process may be started again.

(41) By this process, a new bobbin is provided and prepared for the tobacco sheet on the new bobbin to being spliced with the tobacco sheet in use, while the tobacco sheet is continuously provided to the tobacco processing line.

(42) The bobbin holder 11 is preferably rotated such that a new sheet may be provided from above. This simplifies the positioning of the new sheet on the upper surface of the sheet in use to be joined therewith.

(43) An arrangement of mechanical dancer and pulley rolls 12,13 is provided on the bobbin holder 11 (see FIG. 8). They are arranged next to each of the respective first and second bobbins 30, 40. The tobacco sheets 3, 4 are guided over the rolls 12, 13 before being supplied into the splicing unit 2. By providing mechanical dancers and pulleys 12,13 a controlled guiding of the first or second tobacco sheet, as well as a constant tightening of the tobacco sheet may be achieved. This is especially favourable for tobacco sheet that tends to split or break upon large or irregular tearing or pulling forces. Especially, the rolls make up for varying pulling forces upon rotating the bobbins on the bobbin holder.

(44) The same splicing described above may take place if the control unit receives a signal from a further diameter sensor (not detected) signalling that the first bobbin is going to be depleted soon.

(45) For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term about. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A10 percent of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A represents. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.