EP2674044A1 - Method and apparatus for detecting strand inhomogeneity of a rod of material of the tobacco processing industry - Google Patents

Abstract

The method involves inserting objects (72) into a material rod (71) at predetermined object positions, and conveying the material rod in a longitudinally axial manner through two strand measuring devices (30,40) operated with different frequencies. The measurement signals of the strand measuring devices in the object sections and the blank sections are evaluated with different evaluation processes. A position determination or quality control of the object is carried out in the object sections from the temporal variation of one of the measurement signals in an object algorithm (85a). The blank section algorithm (85b,85c) is applied in the blank sections, with which the strand inhomogeneity is detected, and the strand consistency or quantity of an additive in the material rod is determined. Independent claims are included for the following: (1) an apparatus for use in a rod machine, particularly tobacco rod machine or filter rod machine for detecting strand inhomogeneity of a material rod, particularly of the inserted objects, defective objects and foreign bodies in the tobacco processing industry; and (2) a software program with program code medium for detecting strand inhomogeneity of a material rod, particularly of the inserted objects, defective objects and foreign bodies in the tobacco processing industry.

Description

The invention relates to a method for detecting strand inhomogeneities of a material strand of the tobacco-processing industry, in particular of inserted objects, defective objects and / or foreign bodies, in which objects in a material strand, in particular a tobacco rod or a filter strand, are inserted at predetermined object positions and the material strand after the objects have been inserted longitudinally, at least two strand measuring devices operated at different frequencies are conveyed, which in particular are combined to form a combined strand measuring device, wherein the material strand is subdivided into object sections each containing one or more predetermined object positions and blank sections without predetermined object positions for evaluation of the measurement signals becomes.

The invention further relates to a device for detecting Stranginhomogenitäten a strand of material of the tobacco processing industry, in particular of inserted objects, defective objects and / or foreign bodies, with a Objektinlegevorrichtung by means of the material strand, in particular a tobacco rod or a filter strand, objects at predetermined object positions are inserted or inserted, wherein in the conveying direction at least two strand measuring devices operated or operable with different frequencies are arranged in the material strand downstream of the object insertion device, which are in particular combined to form a combination strand measuring device, by which the material strand is successively conveyed longitudinally or conveyed, wherein an evaluation device is formed, which is designed for the evaluation of Measuring signals of the strand measuring devices the strand of material in object sections, each containing one or more predetermined object positions, and in Leerabs Section without predetermined object positions to divide. Finally, the invention relates to an extrusion machine of the tobacco processing industry, a use and a software program.

The invention relates to the production and testing of a material strand, in particular a tobacco rod or filter rod, for rod-shaped articles of the tobacco-processing industry, in particular for filter cigarettes. The tobacco rod or filter rod is cut to length after its production into individual tobacco rods or filter rods. The filter strand or the cut filter rods or tobacco rods contain as an essential part of one or more objects that influence the smoke or filter properties.

In the case of filter rods or a filter strand, the objects are in particular capsules with a solid shell, which are filled with a liquid. The liquid contains in such Usually flavorings or fragrances, for example menthol. To use a smoker breaks the capsule before smoking by pressure on the filter and then ignites the cigarette. The pressure on the capsule in the filter releases the liquid so that the aroma of the liquid unfolds. This procedure offers a particularly intense or fresh taste experience. Corresponding capsules usually have a diameter of about 3.5 mm, but may also be smaller.

Alternatively, hard objects may also be used as objects in the context of the invention, as may smaller or larger particles, for example spheres or cylindrical objects made of activated carbon, extrudates or other filter materials or additives.

A corresponding object insertion device, with which objects can be inserted into a material strand at high speed, is described for example in German patent application no. 10 2011 017 615.2 the Applicant whose disclosure content is to be incorporated by reference in full in the present application. With this object insertion device, it is possible, even for material strands, are placed in the objects to achieve delivery speeds that are similar to those of material strands without inlaid objects. Thus, for example, a cigarette rod is produced by first chewing tobacco onto a strand conveyor, wrapping the tobacco rod with a wrapping paper strip and then cutting it from the tobacco rod into cigarettes of multiple use length. The forming of the tobacco or filter strand and the subsequent cutting or cutting of the strand takes place at high speed. Typical in today's cigarette and filter making machines strand speeds of 10 m / s, wherein at 100 mm section length, a cutting rate of 100 per second follows.

Furthermore, it is known to measure the strand properties of tobacco strands and filter strands contactless. For example, the moisture and density of the tobacco are measured in the cigarette rod, in particular to control the density. Furthermore, in the case of sudden and short-term signal fluctuations, the presence of foreign bodies is concluded, with the corresponding strand sections subsequently being rejected.

This is done in modern cigarette manufacturing machines with the aid of microwave measuring devices, which have at least one microwave resonator housing, through which the tobacco rod is passed. Also, the measurement of strand properties at much lower frequencies is known. That's how it is DE 10 2004 063 228 B4 a measuring device for determining a dielectric property, in particular the humidity and / or density, of a product, in particular of tobacco, cotton or another fiber product, with a measuring capacitor, a device for generating a high frequency field in the measuring capacitor, which is replaced by a product which is in a measuring volume of the measuring device is arranged, is known.

In the context of the present invention, the term "high frequency" or "HF" basically, as distinct from the microwave range, means frequencies below 300 MHz. As a rule, the frequency is more than 10 kHz, preferably more than 100 kHz. Further preferably, the frequency is at least 1 MHz, in particular for tobacco, more preferably more than 5 MHz, since at lower frequencies towards a sufficiently accurate measurement only in an increasingly limited measuring range is possible.

Examples of microwave strand measuring devices and capacitive HF strand measuring devices are also known from German patent applications no. 10 2011 083 049.9 and no. 10 2011 083 052.9 the applicant, the disclosure of which should be incorporated by reference in its entirety in the present application.

In view of this state of the art, the object of the present invention is to examine different aspects of the strand quality in the case of material strands of the tobacco-processing industry occupied with objects, and in particular to identify strand inhomogeneities with respect to inserted objects and foreign bodies.

This object underlying the invention is achieved by a method for detecting strand inhomogeneities of a strand of material of the tobacco-processing industry, in particular of inserted objects, defective objects and / or foreign bodies, in which a material strand, in particular a tobacco rod or a filter strand, objects predetermined object positions are inserted and the material strand is conveyed longitudinally after inserting the objects by at least two strand frequency measuring devices operated at different frequencies, which are in particular combined to form a combined strand measuring device, wherein the material strand in object sections, each containing one or more predetermined object positions for evaluating the measurement signals, and is divided into blank sections without predetermined object positions, which is further developed by the measurement signals of the strand measuring devices in the object sections and the Leerab each with different evaluation methods are evaluated, in the object sections in an object algorithm, a position determination and / or a quality control of at least one object from the temporal change of at least one of the measured signals is performed and in the empty sections at least one Leerabschnittsalgorithmus is used to recognize the strand inhomogeneities and / or a strand consistency and / or a quantity at least an additive in the material strand, in particular a plasticizer, is or will be determined.

The invention is based on the basic idea that the machine control with the machine cycle and the loading pattern of objects has information enabling an evaluation of microwave strand measuring device signals or capacitive RF strand measuring device signals which is separated into object sections with inserted objects and empty sections without inserted objects and thus also allows different analyzes. In the object sections in an object algorithm not only the presence of an object is checked, for example by exceeding a predetermined threshold level in the object section, but a further analysis is made with determination of the position of the object and optionally a deviation from a desired position. When the deviation of the position of the object from the desired position is exceeded, it can be provided that subsequently an affected strand section is excluded from further processing.

In the empty sections without objects, another evaluation scheme is applied, which is not about determining the exact position of objects, but to determine either the general strand consistency and / or a quantity of at least one additive in the material, in particular a plasticizer. The presence of foreign bodies in the empty section can also be detected. Also, an object that has been mistakenly inserted in a blank portion or that has fallen into an empty portion upon insertion would be recognized as foreign matter. Since an object is not provided in a blank section, it is also to be treated as a foreign body. Affected material strand sections can subsequently be excluded from further processing.

The material strand is preferably conveyed through at least one microwave strand measuring device and / or through at least one capacitive HF strand measuring device as strand measuring devices. This makes it possible to analyze the strand of material with at least two different frequencies, so that significantly different measurement signals occur in response to changes in strand consistency or the presence of foreign objects or objects. If, for example, a microwave strand measuring device and a capacitive HF strand measuring device are used, it is also possible, for example in empty sections, to determine the proportions of various components of the material strand, for example moisture and plasticizer input and the density of the strand, for example in the case of a filter strand.

Since the material strand passes successively through the two strand measuring devices, it is preferably provided that a time offset which occurs between the measuring signals due to a given in the strand conveying direction distance between the strand measuring devices depending on a current material strand conveying speed, by a time shift or a staggered evaluation at least one of the measuring signals is corrected. It is alternatively possible in each case to process the individual measurement signals individually and to correlate the measurement results with the corresponding strand section which has generated the corresponding measurement signals.

An empty-segment algorithm and an object algorithm also mean that different algorithms are used for the evaluation for the different measurement signals of the two strand measuring devices in the empty sections and the object sections. In particular, when using microwave strand measuring devices and capacitive HF strand measuring devices, an individual adjustment of the evaluation parameters will be indicated on the specific features of the microwave measurement signals and the RF measurement signals.

Advantageously, at least one of the strand measuring devices is operated at a variable frequency, wherein a different frequency is used and / or evaluated in the object sections than in the empty sections. In this way it is possible, for example, for the empty sections to achieve an optimization with respect to the measurement of the proportions of additives or moisture or density of the material strand and in the object sections an optimization with respect to the position measurement of the objects or their other parameters such as damage states, degree and size.

Preferably, a first strand measuring device, in particular a microwave strand measuring device, at least temporarily simultaneously with a second strand measuring device, in particular an HF strand measuring device operated, wherein the frequency of the first strand measuring device by a factor of 10 to 900 is greater than the frequency of the second strand measuring device. In this way, more information about the material strand and its Received content that serves to detect strand inhomogeneities or other strand material properties.

Preferably, in the empty sections, in particular in addition, a determination of a moisture and / or the amount of an additive, in particular a plasticizer. Thus, in the empty sections both a recognition of strand inhomogeneities, such as foreign bodies or slipped or incorrectly inserted objects, or droplet formation of plasticizers, which leads to a change in the structure of a filter strand and thus to its uselessness, and at the same time a determination of moisture and / or or a quantity of an additive. This can also be done in the context of two simultaneously exploited evaluation algorithms for the empty sections. For example, an inhomogeneity algorithm can only specify threshold values above which strand homogeneity exists and a known combination measurement takes place with respect to an ingredient measurement, from which the quantities of the various constituents of the material strand are determined, or this can be done together, wherein, for example, the threshold values for the detection of Stranginhomogenitäten also depends on the general consistency of the material strand in the blank section.

In addition, a determination of a missing, a density, a mass and / or a damage of an object preferably takes place in the object sections.

The object underlying the invention is also achieved by a device for detecting strand inhomogeneities of a material strand of the tobacco-processing industry, in particular of inserted objects, defective objects and / or foreign bodies, with an object insertion device, by means of which a material strand, In particular, a tobacco rod or a filter strand, objects at predetermined object positions are inserted or inserted, wherein in the conveying direction of the material strand downstream of the object insertion device at least two operated at different frequencies or operable strand measuring devices are arranged, which are in particular combined into a combination strand measuring device through which the material strand sequentially is longitudinally conveyed or conveyed, wherein an evaluation device is included, which is designed to evaluate the measurement of the strand measuring devices, the strand of material in object sections, each containing one or more predetermined object positions, and divided into empty sections without predetermined object positions, thereby is further developed that the evaluation device is formed, the measuring signals in the object sections and the empty sections, each with unterschiedl evaluate evaluation methods in the object sections in an object algorithm, a position determination and / or quality control of an object from the temporal change of at least one of the measured signals, and at least one empty section algorithm is used in the empty sections, are recognized with the strand inhomogeneities and / or a strand consistency and / or an amount of at least one additive in the material strand, in particular a plasticizer, is or will be determined.

Thus, the device is designed in particular for carrying out the method according to the invention described above. The advantages, properties and features mentioned for the method therefore also apply to the device according to the invention.

Preferably, at least one strand measuring device is a microwave strand measuring device and / or at least one strand measuring device designed as a capacitive RF strand measuring device.

Also advantageously, at least one of the strand measuring devices is designed to be operated at a variable frequency, wherein the one control device or the evaluation device is designed to operate the variable frequency driven strand measuring device in the object sections with a different frequency than in the empty sections. This makes it possible to optimally adapt the measurement with the frequency-variable strand measuring device to the desired measurement parameters for the object sections and the empty sections.

Preferably, the device is designed to carry out a method according to the invention described above.

The object underlying the invention is also achieved by a rod making machine of the tobacco-processing industry, in particular tobacco rod machine or filter rod machine, with a device according to the invention described above. The stranding machine thus has the same features, advantages and properties as the device described above and the previously described method.

The object underlying the invention is further solved by using at least two different evaluation algorithms for the evaluation of measurement signals from strand measuring devices in different sections of a material strand of the tobacco processing industry, are placed in the objects at predetermined object positions, the material strand for evaluation in object sections, the one or more predetermined each Object positions and is divided into empty sections without predetermined object positions, wherein in the object sections, an object algorithm is used in which a position determination and / or a quality control of an object from the temporal change of at least one of the measured signals takes place and in the empty sections at least one empty-section algorithm is used in which strand inhomogeneities and / or a strand consistency and / or an amount of at least one additive in the material strand, in particular a plasticizer, are or will be determined.

Finally, the object underlying the invention is achieved by a software program with program code means by means of which, when executed on an evaluation device, in particular a computer, in particular a microcontroller, a device according to the invention described above, an inventive method described above is performed.

The use and software program thus have the same inventive features, advantages, and features as the method and apparatus described above.

Further features of the invention will become apparent from the description of embodiments according to the invention together with the claims and the accompanying drawings. Embodiments of the invention may satisfy individual features or a combination of several features.

Fig. 1

eine schematische Darstellung einer Zigarettenherstellungsmaschine des Typs "PROTOS" der Anmelderin,

Fig. 2

eine schematische Querschnittsdarstellung durch ein Paar erfindungsgemäßer Strangmessvorrichtungen,

Fig. 3

eine schematische perspektivische Darstellung eines Paares erfindungsgemäßer Strangmessvorrichtungen,

Fig. 4

eine schematische Darstellung einer Signalverarbeitung,

Fig. 5

eine weitere schematische Darstellung einer erfindungsgemäßen Signalverarbeitung,

Fig. 6

eine schematische Darstellung einer erfindungsgemäßen Vorrichtung.

The invention will be described below without limiting the general inventive concept by means of embodiments with reference to the drawings, wherein with respect to all unspecified in the text details of the invention expressly referred to the drawings. Show it:

Fig. 1

a schematic representation of a cigarette making machine of the type "PROTOS" of the applicant,

Fig. 2

a schematic cross-sectional view through a pair of strand measuring devices according to the invention,

Fig. 3

a schematic perspective view of a pair of strand measuring devices according to the invention,

Fig. 4

a schematic representation of a signal processing,

Fig. 5

a further schematic representation of a signal processing according to the invention,

Fig. 6

a schematic representation of a device according to the invention.

In the drawings, the same or similar elements and / or parts are provided with the same reference numerals, so that apart from a new idea each.

In Fig. 1 For example, there is schematically illustrated a two-strand "PROTOS" cigarette making machine of the Applicant Company assembled in a "L-shaped" configuration from a two-strand machine 2 and a filter attachment machine 3. In Fig. 1 the machine 1 is shown with closed top plates, details are not shown for clarity.

In the following, some stations of cigarette production are presented clearly. The production process of two endless tobacco strands begins in the two-line machine 2 in a two-strand distribution unit 4 with a pre-distributor 5, which includes, inter alia, a steep conveyor and two storage chutes and other known components. Therein, loose tobacco material is conveyed to a first and a parallel second strand conveyor 6 and thrown from below onto the strand conveyors, so that two tobacco strands are formed, which are held by means of suction air on the strand conveyors. Hanging on the strand conveyors 6, the tobacco material is conveyed in the direction of a first and a second format unit 8. There, the still open tobacco strands are each wrapped in a wrapping paper unit 7 with wrapping paper strips, which are glued to a longitudinal edge. Subsequently, the tobacco strands in the two format units 8 are formed into two endless closed tobacco strands of circular cross section and the gluing of the wrapping paper strips is solidified.

After the tobacco rods have been formed, they are guided by a measuring device 9 with one or more measuring units for measuring properties of the respective tobacco material strand. For example, the wrapping paper is visually inspected and the moisture content and density are measured. The control of the two-line machine 2 takes place from a control console 11.

Output of the two-strand machine 2 is a knife and transfer unit 10, in which the strands are cut into individual tobacco rods multiple use length, the individual tobacco rods are deflected from a longitudinal axial to a transverse axial promotion and transferred to the filter attachment machine 3. The filter attachment machine 3 has, inter alia, a lining paper unit 12, peeled off from the tipping paper, cut and glued. Subsequently, the individual tipping paper leaflets are wrapped in designated areas around the tobacco rods and double filter plugs, which are thereby connected together. Finally, the double cigarettes produced in this way are cut in the middle and transported away one by one.

In Fig. 2 a combination strand measuring device 20 which can be used according to the invention is shown schematically in cross section. The combination strand measuring device 20 has a common housing 21, which is penetrated by a protective tube 23 through which a strand of material, such as a filter strand or a tobacco rod, is guided, wherein the strand of material first enters through a strand inlet tube 22 with conical inner diameter before passing through the Protective tube 23 passes.

The combination strand measuring device 20 has in the strand conveying direction sequentially a microwave strand measuring device 30 and a capacitive HF strand measuring device 40. The microwave strand measuring device 30 corresponds for example to a microwave strand measuring device, as described in the German patent application no. 10 2011 083 049.9 the applicant is described. This has a microwave resonator 31 in a microwave resonator housing 32. In the microwave resonator 31, a coupling-in antenna 33 and a coupling-out antenna 34 project for coupling and coupling-out of microwaves in the frequency range between 5 and 9 GHz. The microwave resonator 31 is substantially cylindrically shaped, wherein the protective tube 23 passes centrally through the cylindrical microwave resonator 31. In the center, around the protective tube 23 around, there are two conical collar 35, whose effect is also in the German patent application no. 10 2011 083 049.9 is described and their this disclosure content should be included in this application. In the strand direction downstream and upstream of the conical collar 35 are undercuts 36 whose inner diameter is widened again in relation to the tips of the conical collar 35, with the result that the microwave field in the axial direction, ie in the direction of the material strand, does not protrude far, and in particular does not enter the subsequent capacitive RF strand measuring device 40.

With regard to the microwave strand measuring device 30, the common housing 21 also contains a plurality of cavities with measuring, tempering and power electronics 37, which is thus integrated into the microwave strand measuring device 30. This has the further advantage that the power and measurement electronics have the same temperature as the microwave resonator 31 and thus results in a temperature control for the entire microwave strand measuring device 30.

The following capacitive RF strand measuring device 40 has a measuring capacitor 41 with a capacitor housing 42 and electrode surfaces 43, 44. An RF alternating voltage in the range between 10 MHz and about 500 MHz is applied to this. A corresponding capacitive RF strand measuring device is known from German patent application no. 10 2011 083 052.9 the applicant, the relevant disclosure of which should also be included by reference in the present patent application. Also, the capacitive RF strand measuring device 40 has with respect to the electrode surfaces 43 and 44 conical collar 45, with which the geometry of the measuring capacitor 41 is adapted to the geometry of the microwave resonator 31. The measurement signals of the microwave strand measuring device 30 and the capacitive RF strand measuring device 40 are thus also with respect to the geometry of the microwave resonator 31 and the measuring capacitor 41 and thus the electromagnetic alternating fields directly comparable. The conical collar 45 with the corresponding undercuts ensure that even in this case the RF fields in the axial direction of the material strand do not penetrate far out of the measuring capacitor 41 and, in particular, do not penetrate into the microwave resonator 31.

The capacitive HF strand measuring device 40 has integrated measuring, temperature control and power electronics 47 in cavities of the common housing 21. All power electronics, measuring electronics and the temperature control of the entire combination strand measuring device 20 is thus integrated in the combination strand measuring device 20.

In Fig. 3 is the combination strand measuring device 20 from Fig. 2 shown schematically in a perspective view. The observer looks at the front side of the combination strand measuring device 20 with the microwave strand measuring device 30 and the strand inlet tube 22 and the inside visible protective tube 23. Behind it is the capacitive RF strand measuring device 40. The individual housings are connected to a common housing.

In Fig. 4 a first aspect of a signal processing of measurement signals 51, 52 of a first strand measuring device and a second strand measuring device is shown. These may come from a variety of strand measuring devices or from two similar strand measuring devices operating at different frequencies. A first measurement signal 51 of a first strand measuring device, through which a section of a material strand initially passes through objects, has a signal course to which a second measurement signal 52 from a second strand measuring device, which is arranged downstream of the first strand measuring device, has a time offset Δt. For evaluation of these measurement signals, in an evaluation device, which is designed in particular as a digital signal processing system, in particular as a computer, this time offset is eliminated in a shift algorithm 53, so that after application of the shift algorithm 53, the two measurement signals 51, 52 match each other in time. These corrected measuring signals 51, 52 are then fed to an evaluation 54. The evaluation according to the invention will be further described below. The machine cycle 55 is used both for the evaluation and for the displacement or the correction of the time offset.

In Fig. 5 FIG. 2 shows the time profile of a measurement signal 51 whose amplitude is influenced by the presence or absence of objects in the material strand. Thus, high measurement signal amplitudes 63 correspond to the objects and low measurement signal amplitudes 64 correspond to the empty sections of the material strand. Since the machine control has information on which sections of the material strand objects should be present and in which sections this should not be the case, the measurement signal 51 is subdivided into object sections 61 and empty sections 62 for evaluation, wherein in Fig. 5 In the example shown, the object sections 61 each comprise two objects located therein, and the blank sections 62 comprise a portion of the gap between the object sections 61. The blank sections 62 in this case do not comprise the entire gap between the object sections 61, but those sections in which the residual effects of the objects on the measurement signal have subsided, so that a substantially constant signal course in the blank section 62 is to be expected. Therefore, the object portions 61 and the blank portions 62 have different boundaries 65-68. The large signal amplitude variations due to the objects are thus avoided in the blank sections 62. According to the invention, other evaluation algorithms are used in the empty sections 62 than in the object sections 61. This not only applies to the application of different limit values for the detection of strand inhomogeneities or consistency measurements of the material strip, but also to the concrete exact determination of the position of the inserted objects.

Fig. 6 schematically represents a device 80 according to the invention, by means of strand inhomogeneities can be seen. In this case, a strand of material 71 with inserted objects 72 by one, for example in the FIGS. 2 and 3 shown combination strand measuring device 20 with a microwave strand measuring device 30 and a capacitive RF strand measuring device 40 in the strand conveying direction 75 promoted. As additional inhomogeneity, a foreign body 74 is shown. In addition, an object 73 is defective. This may be, for example, a capsule that is damaged and has lost its fluid content. This would be done in a measurement waveform according to Fig. 5 produce a lower measurement signal amplitude in the peak than an undamaged object 72.

The device 80 has an input and display device connected to the machine controller 82. Among other things, the machine controller 82 receives a signal from a pulser, which may be a high accuracy encoder, angle encoder, or the like. The machine controller 82 also has a machine clock signal, which generally synchronizes the various string device components to the length of the machine cut material strand sections takes place.

An evaluation device 83 is provided which can also be integrated in the data processing system of the machine control 82. The evaluation device 83 is in particular a data processing system, ie in particular a computer, on which a software program is executed, which may have various algorithms, namely an object algorithm 85a, a strand consistency algorithm 85b and a foreign body algorithm 85c. Other algorithms may be used, for example, a shifting algorithm that uses the machine cycle. The latter is used continuously. In addition, an algorithm selection and switching 86 is provided, by means of which, depending on whether the strand section currently to be analyzed is an empty section or an object section, it is selected which evaluation algorithm is to be used for this section.

Algorithm selection and switching 86 is also connected to the pulse generator 88 on the one hand, and algorithm selection and switching 86, on the other hand, receives a control signal 90 for switching and a cut signal 91 from the machine controller 82 for precise timing for the object sections and the blank sections to determine. The switching control signal 90 includes information as to whether it is a blank portion or an object portion. Furthermore, the evaluation device 83 receives information about where items should be located. Thus, the object algorithm 85a may be used to verify that objects are located at the intended locations within tolerable limits.

The further algorithms 85b, 85c are used to detect foreign objects, in particular metal particles, slipped objects or droplets of plasticizers, or to carry out a consistency measurement with respect to density, moisture in a tobacco rod or a filter strand and, for example, plasticizer entry in a filter strand and check.

The position determination in the object sections and in the object algorithm 85a takes place by analyzing the time profile of one or both measuring signals of the strand measuring devices. Thus, as a measure, a temporal course of the measurement signal can be predetermined within certain limits, so that if the concrete measurement signal in the object section does not exceed the upper and lower limits, which are temporally variable and above and below a standard curve, they are recognized as standard-compliant so that the object position is determined in this way. Also a fast determination of the maximum of the signal is possible. Also, an analysis of the rising and falling edges of the corresponding measurement signal is possible to determine the object position. Corresponding methods are known. The initially described method with the predetermined course describing a course of the standard with a correspondingly changed upper limit and lower limit also takes into account the short-term and high-frequency fluctuations occurring in the case of corresponding measurement signals in the signal with a low fluctuation amplitude. The specification of the standard curve, which corresponds to or follows the actual course of a measurement signal for an ideally placed object in the material strand, thereby enables a position determination for the object that is not possible with a conventional application of a threshold value crossing comparison.

All the features mentioned, including the drawings to be taken alone as well as individual features disclosed in combination with other features are considered alone and in combination as belonging to the invention. Embodiments of the invention may be accomplished by individual features or a combination of several features.

LIST OF REFERENCE NUMBERS

1

machine

2

rod machine

3

filter attachment

4

distribution unit

5

preliminary distributor

6

line conveyor

7

Wrapping paper unit

8th

format unit

9

measuring device

10

Knife and transfer unit

11

control panel

12

Tipping paper unit

20

Combination leg metering device

21

common housing

22

Strand inlet pipe

23

thermowell

30

Microwave leg metering device

31

microwave

32

Mikrowellenresonatorgehäuse

33

Einkopplungsantenne

34

decoupling antenna

35

conical collar

36

undercut

37

Measuring, temperature control and power electronics

40

Capacitive HF strand measuring device

41

measuring capacitor

42

capacitor case

43, 44

electrode area

45

conical collar

46

undercut

47

Measuring, temperature control and power electronics

51

Measuring signal from a first strand measuring device

52

Measuring signal from a second strand measuring device

53

shift algorithm

54

evaluation

55

machine cycle

61

Property section

62

empty section

63

Measurement signal amplitude with object

64

Measurement signal amplitude without object

65, 66

Limits of an object section

67, 68

Limits of a blank section

71

material strand

72

inserted object

73

defective object

74

foreign body

75

Strand conveying direction

80

contraption

81

Input and display device

82

machine control

83

evaluation

85a

object algorithm

85b

Train consistency algorithm

85c

Foreign bodies algorithm

86

Algorithm selection and switching

88

pulse

90

Control signal for switching

91

cut signal

Claims (14)

Method for detecting strand inhomogeneities (72, 73, 74) of a material strand (71) of the tobacco processing industry, in particular of inserted objects (72), defective objects (73) and / or foreign bodies (74), in which a material strand (71 ), in particular a tobacco rod or a filter strand, objects (72) are inserted at predetermined object positions and the material strand (71) after inserting the objects (72) longitudinally through at least two with different frequencies driven strand measuring devices (30, 40) is promoted, in particular to a combination strand measuring device (20) are summarized, wherein for evaluating the measuring signals (51, 52) of the material strand (71) into object sections (61), each containing one or more predetermined object positions, and divided into empty sections (62) without predetermined object positions , characterized in that the measuring signals (51, 52) of the strand measuring devices (30, 40) in the object sections (61) and the empty sections (62) are respectively evaluated with different evaluation methods, wherein in the object sections (61) in an object algorithm ( 85a) a position determination and / or a quality control of at least one object (72) from the temporal change of at least one of the measuring signals (51, 52) takes place and in the empty sections (62) at least one empty section algorithm (85b, 85c) is used, with the strand inhomogeneities (72, 73, 74) are recognized and / or a strand consistency and / or an amount of at least one additive in the material strand (71) is or will be determined. A method according to claim 1, characterized in that the strand of material (71) by at least one microwave strand measuring device (30) and / or by at least one capacitive RF strand measuring device (40) is promoted as strand measuring devices. A method according to claim 1 or 2, characterized in that for evaluation, a time offset occurring between the measuring signals (51, 52) due to a given in strand conveying direction (75) distance between the strand measuring devices (30, 40) depends on a current material strand conveying speed, is corrected by a time shift or a staggered evaluation of at least one of the measurement signals (51, 52). Method according to one of claims 1 to 3, characterized in that at least one of the strand measuring devices (30, 40) is operated at a variable frequency, wherein in the object sections (61) a different frequency is used and / or evaluated as in the empty sections (62). Method according to one of claims 1 to 4, characterized in that a first strand measuring device, in particular a microwave strand measuring device (30), at least temporarily simultaneously with a second strand measuring device, in particular an HF strand measuring device (40) is operated, wherein the frequency of the first strand measuring device by a factor of 10 to 900 greater than the frequency of the second strand measuring device. Method according to one of claims 1 to 5, characterized in that in the empty sections (62), in particular in addition, a determination of a moisture and / or the amount of an additive, in particular a plasticizer takes place. Method according to one of claims 1 to 6, characterized in that in the object sections (61) additionally a determination of a missing, a density, a mass and / or a damage of an object (72). Device (80) for detecting strand inhomogeneities (72, 73, 74) of a material strand (71) of the tobacco processing industry, in particular of inserted objects (72), defective objects (73) and / or foreign bodies (74), with an object insertion device, by means of which in a strand of material, in particular a tobacco rod or a filter strand, objects (72) are inserted or inserted at predetermined object positions, wherein in the conveying direction (75) of the strand of material (71) downstream of the object insertion device at least two running at different frequencies or operable strand measuring devices (30, 40) are arranged, which are in particular combined to form a combined strand measuring device (20) through which the material strand (71) successively longitudinally conveyed or conveyed, wherein an evaluation device (83) is included adapted to evaluate measurement signals (51, 52) of the strand measuring devices (30, 40) the strand of material (71) in object sections (61), each containing one or more predetermined object positions, and in empty sections (62) without predetermined object positions to subdivide, characterized in that the evaluation device (83) is designed to evaluate the measurement signals (51, 52) in the object sections (61) and the empty sections (62), each with different evaluation methods, wherein for evaluation in the object sections (61) in an object algorithm (85a) a position determination and / or a Qualitä tskontrolle an object (72) from the temporal change of at least one of the measuring signals (51, 52) takes place and in the empty sections (62) at least one Leerabschnittsalgorithmus (85b, 85c) is used with the strand inhomogeneities (72, 73, 74) are detected and / or a strand consistency and / or an amount of at least one additive in the material strand (71) is or will be determined. Device (80) according to claim 8, characterized in that at least one strand measuring device (30, 40) as a microwave strand measuring device (30) and / or at least one strand measuring device (30, 40) is designed as a capacitive RF strand measuring device (40). Device (80) according to claim 8 or 9, characterized in that at least one of the strand measuring devices (30, 40) is designed to be operated at variable frequency, wherein the one control device (82) or the evaluation device (83) is designed to drive the variable frequency strand measuring device (30, 40) in the object sections (61) to operate at a different frequency than in the empty sections (62). Device (80) according to one of claims 8 to 10, characterized in that it is designed to carry out a method according to one of claims 1 to 7. Extrusion machine (2) of the tobacco-processing industry, in particular tobacco rod machine or filter rod machine, having a device (80) according to one of claims 8 to 11. Use of at least two different evaluation algorithms (85a, 85b, 85c) for evaluating measurement signals (51, 52) of strand measuring devices (30, 40) in different sections (61, 62) of a material strand (71) of the tobacco processing industry, in the objects ( 72) are inserted at predetermined object positions, wherein the material strand (71) is subdivided for evaluation into object sections (61) which respectively contain one or more predetermined object positions and into empty sections (62) without predetermined object positions, wherein in the object sections (61) an object algorithm (85a) is used, in which a position determination and / or a quality control of an object (72) from the temporal change of at least one of the measuring signals (51, 52) takes place and in the empty sections (62) at least one empty section algorithm (85b, 85c ), with strand inhomogeneities (72, 73, 74) and / or strand consistency and / or an amount of at least one additive in the material strand (71) is or will be determined. Software program with program code means, by means of which, when executed on an evaluation device (83) of a device (80) according to one of claims 8 to 11, a method according to one of claims 1 to 7 is carried out.

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