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The present invention relates to a method for determining the conformance of an embossing on a web of material, in particular, tipping paper, intended for forming a rod-shaped, multisegment article.
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The present invention further relates to a combiner or filter tip attachment machine, in particular configured to carry out the aforesaid method.
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It is known that in the production of rod-shaped, multisegment articles, it is particularly important for the articles to conform to a required quality and/or dimensional standard. Therefore, the need to inspect the articles for checking the conformance thereof is particularly felt in such a situation.
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In particular, to date, the need is strongly felt to inspect the embossing made on the tipping paper of such articles so as to evaluate the conformance thereof. Indeed, such an embossing must comply with predetermined dimensional, positional and/or quality standards.
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Furthermore, in the production of rod-shaped, multisegment articles, to date, the need is felt to manufacture articles which are particularly aesthetically appealing as well as easily recognizable, i.e., having an appearance that, to the consumer's eye, immediately recalls the article of a particular type and/or brand.
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Therefore, in such a context, the need exists for the embossing to conform to a predetermined and desired embossing type in addition to being correctly made in terms of size and/or position.
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To date, in order to check the embossing, it is known to pick one or more of these articles after the tipping paper has been enfolded around the respective rod-shaped, multisegment articles to carry out a visual inspection, in particular offline.
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In more detail, one or more rod-shaped, multisegment articles are randomly extracted from the stream of articles and inspected to check that the embossing is made correctly.
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In particular, it is known to perform an optical inspection of such articles, e.g., by means of cameras. In such a situation, light sources are used to illuminate the article and cameras are used to detect the light reflected by the article itself. Data on qualitative properties of the embossing, such as type or size, for example, can be derived based on such a detection. Alternatively, the inspection is done with the aid of an operator who, after having picked the article from the stream, inspects it by means of appropriate manual tools to detect the embossing parameters. Disadvantageously, random checks on the rod-shaped, multisegment articles do not ensure conformance of all produced articles. Therefore, such checks are rather unreliable because it do not ensure the detection of all defective articles.
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Furthermore, the fact of checking the embossing conformance when the embossed tipping paper has already been applied to the articles results in that, if such a check reveals defects, all corresponding defective articles will have to be rejected.
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Hence, it is the technical task of the present invention to provide a method for determining the conformance of the embossing on a web of material and a combiner or filter tip attachment machine which are capable of overcoming the drawbacks arising from the prior art.
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In particular, it is the object of the present invention to provide a method for determining the conformance of an embossing on a web of material that is accurate and reliable.
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Therefore, it is the further object of the present invention to provide a method for determining the conformance of an embossing on a web of material which allows greatly decreasing the number of defective formed articles. It is a further object of the present invention to provide a reliable and efficient combiner or filter tip attachment machine.
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In the scope of such a technical task, the Applicant found that using a laser detector, in particular a 3D laser scanner, it is possible to perform a three-dimensional reconstruction of the embossing profile (whether planar, thus detected on the paper prior to enfolding, or curved, detected on already formed articles), such a reconstruction giving rise to a virtual 3D model which can be processed to obtain the desired quality information. Moreover, this allows for online and nondestructive checks of articles, allowing the inspection of the entire production.
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The specified technical task and objects are substantially achieved by a method for determining the conformance of an embossing on a web of material and by a combiner or filter tip attachment machine comprising the technical features set out in one or more of the appended claims. The dependent claims correspond to possible embodiments of the invention.
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In particular, the specified technical task and objects are achieved by a method for determining the conformance of an embossing on a web of material, in particular tipping paper, intended for forming a rod-shaped, multisegment article.
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The method comprises a step of feeding a web of material, in particular tipping paper or "cork" paper, along a feed path.
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The method further comprises a step of making a succession of embossings on the web of material.
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The method comprises a step of making a succession of rod-shaped, multisegment articles by means of at least one portion of the web of material so that each article is provided with at least one respective embossing. The method thus comprises a step of detecting, by means of an inspection module comprising a laser detector, at least one embossed portion of one or more of the embossings.
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Preferably, the laser detector is a 3D laser scanner.
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Preferably, the step of detecting at least one embossed portion of one or more of the embossings is carried out on the web of material.
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Alternatively, the step of detecting at least one embossed portion of one or more of the embossings is carried out on one or more multisegment articles. Preferably, in such a situation, the step of detecting at least one embossed portion of one or more of the embossings is carried out offline.
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Alternatively, the step of detecting at least one embossed portion of one or more of the embossings is carried out online.
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According to a possible embodiment, the method comprises a first step of detecting, by means of a first inspection module comprising a laser detector, at least one embossed portion of one or more of the embossings on the web of material, and a second step of detecting, by means of a second inspection module comprising a laser detector, at least one embossed portion of one or more of the embossings on one or more multisegment articles.
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Even more preferably, the method comprises a step of comparing the first and second detections, associated with the same embossed portion, and of determining, based on the comparison, the variation in embossing quality between the first and second detections.
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Based on the detection (whether single or double), the method comprises a step of reconstructing a virtual 3D model of the embossed portion by means of a processing unit.
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The method comprises a step of processing the 3D model to generate at least one signal identifying one or more of the following conditions:
- embossing of quality conformant or non-conformant with a reference quality for the current process;
- embossing correctly or incorrectly positioned;
- embossing of a type conformant or non-conformant with a type of embossing expected for the current process.
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Preferably, the step of processing the 3D model comprises a step of checking a condition of deterioration of the embossed portion, in particular the presence of tears and/or holes. In such a situation, if such a presence is detected, the method preferably comprises at least one of the following steps:
- generating an alarm signal for an operator;
- generating a stop signal to discontinue the process of forming the multisegment articles;
- generating a rejection signal for one or more multisegment articles corresponding to the deteriorated embossed portion.
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Preferably, the step of processing the 3D model comprises a step of determining at least one dimensional or positional parameter of the embossing.
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According to an embodiment, in such a situation, the signal identifies the conformant or non-conformant quality condition and the parameter is a dimensional parameter of the embossing, in particular the embossing height.
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Preferably, if the generated signal identifies an embossing of non-conformant height, the method comprises at least one of the following steps:
- generating an alarm signal for an operator;
- generating a stop signal to discontinue the process of forming the multisegment articles;
- generating a command signal identifying a corrective action to be performed, preferably automatically, during the step of making the embossings.
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According to another embodiment, the signal identifies the condition of correctly or incorrectly positioned embossing. In such a situation, the method comprises a step of detecting one or more signs and/or markings and/or end edges of the web of material. Doing so, the determination of the condition of correctly or incorrectly positioned embossing is carried out by determining the position of the embossed portion with respect to the one or more signs and/or markings and/or end edges.
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Alternatively to the aforesaid two embodiments, the signal identifies the conformant or non-conformant type. In such a situation, the step of processing the 3D model comprises a step of comparing the 3D model, or one or more projections thereof, with a reference 3D model or with one or more reference images.
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Preferably, if a signal identifying an embossing of non-conformant type or an incorrectly positioned embossing is generated, the method comprises at least one of the following steps:
- generating an alarm signal for an operator;
- generating a stop signal to discontinue the process of forming the multisegment articles.
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The specified technical task and objects are also achieved by a combiner or filter tip attachment machine, in particular configured to carry out the method described above.
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The machine comprises at least two feed lines for feeding rod-shaped segments. At least one of the segments is a filter segment.
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In the case of a combiner machine, the segments conveyed by the at least two feed lines are filter segments.
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In the case of a filter tip attachment machine, one of the segments is a filter segment while the other one is a tobacco segment.
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The machine comprises a conveyor drum arranged downstream of the feed lines and configured to feed a succession of groups of rod-shaped segments. Each group comprises at least two segments. The conveyor drum is a combiner drum or is arranged downstream of a combiner drum. The machine comprises a feed line for feeding a web of material, in particular tipping paper, configured to feed the web of material along a feed path.
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The machine comprises an embossing unit arranged along the feed path and configured to make a succession of embossings on the web of material. The machine comprises an applicator unit, configured to divide the web of material into connecting strips so that each connecting strip comprises at least one embossing and apply each connecting strip in a flag-like manner to a respective group of segments supported by the conveyor drum.
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The machine comprises a rolling unit in which each connecting strip is enfolded around the respective group of segments to obtain a multisegment article.
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The machine comprises at least one inspection module comprising a laser detector and configured to detect at least one embossed portion of one or more of the embossings.
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Preferably, the at least one inspection module is arranged along the feed path of the web of material.
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Alternatively, the at least one inspection module is arranged downstream of the rolling unit.
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The machine further comprises a processing unit configured to determine, on based on the detection, the reconstruction of a virtual 3D model of the embossed portion by means of a processing unit and process the 3D model to generate at least one signal identifying one or more of the following conditions:
- embossing of quality conformant or non-conformant with a reference quality for the current process;
- embossing correctly or incorrectly positioned;
- embossing of a type conformant or non-conformant with a type of embossing expected for the current process.
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Further features and advantages of the present invention will become more apparent from the indicative, and thus non-limiting, description of an embodiment for determining the conformance of an embossing on a web of material and a combiner or filter tip attachment machine.
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Such a description will be set out below with reference to the accompanying drawings, provided for indicative and thus non-limiting purposes only, in which:
- Figure 1 is a diagrammatic view of a filter tip attachment machine of the present invention operating according to the method of the present invention;
- Figure 2 is a diagrammatic view of a combiner machine of the present invention operating according to the method of the present invention.
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A method for determining the conformance of an embossing on a web "N" of material, in particular tipping paper, intended for forming a rod-shaped, multisegment article object of the present invention will be described below. The method comprises a step of feeding a web "N" of material along a feed path.
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The method further comprises a step of making a succession of embossings on the web "N" of material.
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Preferably, the embossings are made in an embossing unit 100 comprising at least one pair of embossing rollers 100a, 100b mutually meshing and appropriately spaced apart to define a passage gap for the web "N" of material. In such a situation, the web "N" of material, while feeding through the passage gap, is embossed, i.e., is deformed by the embossing rollers 100a, 100b.
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The method then comprises a step of making a succession of rod-shaped, multisegment articles by means of at least one portion of the web "N" of material so that each article is provided with at least one respective embossing.
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Preferably, after the step of making a succession of embossings on the web "N" of material, the method comprises a step of cutting the web "N" of material thus embossed to obtain a plurality of discrete embossed portions, e.g., embossed connecting strips.
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Preferably, after the step of cutting, the method comprises a step of enfolding in which each discrete embossed portion is enfolded around a respective article so that each article has at least one respective embossing. The method further comprises a step of detecting, by means of an inspection module 200 comprising a laser detector 201, at least one embossed portion of one or more of the embossings.
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Preferably, the laser detector 201 is a 3D laser scanner.
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According to an embodiment, the step of detecting at least one embossed portion of one or more of the embossings is carried out on the web "N" of material.
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In other words, the detection step is carried out along the feed path "P" of the web "N" of material, i.e., when the web "N" of material has a flat configuration and is continuous, i.e., it is not yet divided into discrete portions.
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According to a further embodiment, the step of detecting at least one embossed portion of one or more of the embossings is carried out on one or more multisegment articles.
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In other words, the detection step is carried out after the step of making a succession of rod-shaped, multisegment articles. In such a situation, once the portion of the web "N" of material has been enfolded around the respective article, the inspection module 200 detects the embossing on such a portion.
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In such a situation, the step of detecting at least one embossed portion of one or more of the embossings can be carried out offline.
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Doing so, the rod-shaped, multisegment articles are diverted from the feed or working path "P" to be inspected.
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Alternatively, the step of detecting at least one embossed portion of one or more of the embossings can be carried out online, i.e., while the rod-shaped, multisegment articles are fed along the normal feed or working path "P".
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According to a further embodiment, the method comprises a first step of detecting, by means of a first inspection module comprising a laser detector, at least one embossed portion of one or more of the embossings on the web "N" of material, and a second step of detecting, by means of a second inspection module comprising a laser detector, at least one embossed portion of one or more of the embossings on one or more multisegment articles.
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In such a situation, the method further comprises a step of comparing the first and second detections, associated with the same embossed portion, and of determining, based on the comparison, the variation in embossing quality between the first and second detections.
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The comparison between the first and second detections is useful to understand whether there were moments when the embossing suffered "damage", e.g., was crushed, the paper tipping was torn and the like, along the feed path "P", and in particular between the point in which the first detection is performed and the point in which the second detection is performed.
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Thus, in use, by determining the variation in embossing quality between the first and second determinations, it is possible to determine if there are moments during the manufacturing of the rod-shaped, multisegment article when the embossed web "N" of material and/or a discrete embossed portion thereof have been damaged.
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Based on the detection (whether carried out on the succession of embossings made on the web "N" of material and/or on the embossed portions of the web "N" of material enfolded around the respective articles), the method comprises a step of reconstructing a virtual 3D model of the embossed portion by means of a processing unit "U".
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In other words, a digital three-dimensional reconstruction of the "scanned" embossed portion can be obtained by virtue of the detection carried out by the inspection module 200. Therefore, such a digital three-dimensional scan reproduces the shape, size and other features peculiar to the embossed portion just detected, i.e., it faithfully reproduces the embossed portion digitally.
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After the reconstruction step, the method comprises a step of processing the 3D model to generate at least one signal identifying one or more of the following conditions:
- embossing of quality conformant or non-conformant with a reference quality for the current process;
- embossing correctly or incorrectly positioned;
- embossing of a type conformant or non-conformant with a type of embossing expected for the current process.
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According to a possible embodiment, the step of processing the 3D model comprises a step of determining at least one dimensional or positional parameter of the embossing.
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If a dimensional parameter is determined, the signal identifies the conformant or non-conformant quality condition.
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In particular, the dimensional parameter determined can be the embossing height. In such a situation, the embossing height is measured when the 3D model is processed.
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The term "embossing height" refers to the distance between a peak and a corresponding valley of the embossing.
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If such a height is approximately equal to the expected and desired height (or otherwise its value deviates from the desired value by an acceptable amount, i.e., it is within a range of acceptable values), the conformant quality condition is derived. Conversely, if such a height deviates unacceptably from the desired height (i.e., the value is outside the range of acceptable values), the non-conformant quality condition is derived.
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Preferably, if the signal identifying the embossing of non-conformant height is generated, the method comprises at least one of the following steps:
- generating an alarm signal for an operator. In such a situation, the alarm alerts the operator who, for example, stops feeding the web "N" of material and/or manually adjusts the distance between the embossing rollers 100a, 100b so that the embossing made from then on has a height conformant with that desired;
- generating a stop signal to discontinue the process of forming the multisegment articles. In such a situation, the production of articles is stopped so as to avoid enfolding such articles with portions of embossed web of material in which the embossing does not have the desired height. Doing so, the production of non-conformant articles (and thus to be rejected) is avoided;
- generating a command signal identifying a corrective action to be performed, preferably automatically, during the step of making the embossings. In such a situation, once the signal identifying a non-conformant height embossing is generated, the command signal identifying a corrective action to be taken is derived. In the preferred embodiment, the command identifying a corrective action identifies a mutual approaching or distancing movement of the embossing rollers 100a, 100b. In such a situation, the embossing height is adjusted by means of a feedback control based on the incorrect height detected by processing the 3D model.
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In other words, when it is derived that the embossing height does not conform to the expected one, the embossing rollers 100a, 100b are moved closer or farther apart from each other to make an embossing of desired height based on the detected embossing height.
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On the other hand, if a positional parameter is determined, the signal identifies the condition of correctly or incorrectly positioned embossing.
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In such a situation, the method comprises a step of detecting one or more signs and/or markings and/or end edges of the web of material. In such a situation, the determination of the condition of correctly or incorrectly positioned embossing is carried out by determining the position of the embossed portion with respect to the one or more signs and/or markings and/or end edges.
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By way of non-limiting example, a cutting line can be detected in the aforesaid detection step, along which the web "N" of material must be cut, after embossing, to define the discrete embossed portions. In such a situation, the position of the embossed portion with respect to such a cutting line is derived. If the embossing is sufficiently distant from such a cutting line (i.e., its distance falls within a predetermined range of acceptable values), then the condition of correctly positioned embossing is obtained. Conversely, if the embossing is too close to the cutting line or even has been made above the cutting line, then the condition of incorrectly positioned embossing is obtained.
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In the latter case, i.e., if the signal identifying an incorrectly positioned embossing is generated, the method comprises at least one of the following steps:
- generating an alarm signal for an operator. In such a situation, the operator can, for example, stop the step of making a succession of embossings on the web "N" of material and/or the step of making a succession of rod-shaped, multisegment articles;
- generating a stop signal to discontinue the process of forming the multisegment articles. In such a situation, the production of multisegment articles with incorrectly embossed portions, i.e., multisegment articles to be rejected, is avoided.
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According to a possible embodiment, additionally or alternatively to the determination of at least one dimensional or positional parameter of the embossing, a signal identifying the conformant or non-conformant type is generated from the step of processing the 3D model.
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In such a situation, the step of processing the 3D model comprises a step of comparing the 3D model, or one or more projections thereof, with a reference 3D model or with one or more reference images.
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Preferably, at least one qualitative indicator, e.g., a congruence percentage level, is derived from such a comparison, which indicates how similar or equal the 3D model (or an image thereof) is to the reference 3D model (or an image thereof).
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For example, if an embossing having a sawtooth profile is desired, the reference 3D model is a model in which the embossing has such a profile. At the time of comparison, the generated 3D model is compared with the reference 3D model. If, from such a comparison it is noted that the generated 3D model has the same profile as the sawtooth profile, the indicator will indicate the complete congruence between the profiles. If, from such a comparison, it is noted that the generated 3D model has a profile similar to the sawtooth profile, the indicator will indicate the percentage of congruence between the profiles. If, from such a comparison, it is noted instead that the generated 3D model has a totally different profile from the sawtooth profile, the indicator will indicate the total incongruence of the profiles. In such a situation, an embossing identification signal of non-conformant type is derived. If such a condition is derived, the method comprises at least one of the following steps:
- generating an alarm signal for an operator. In such a situation, the operator can stop the step of making a succession of embossings on the web "N" of material and/or the step of making a succession of rod-shaped, multisegment articles;
- generating a stop signal to discontinue the process of forming the multisegment articles. In such a situation, the production of multisegment articles with incorrectly embossed portions, i.e., multisegment articles to be rejected, is avoided.
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According to an aspect of the present invention, the step of processing the 3D model further comprises a step of checking a condition of deterioration of the embossed portion.
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In particular, the presence of tears and/or holes is checked in such a step. If such a presence is detected, the method preferably comprises at least one of the following steps:
- generating an alarm signal for an operator;
- generating a stop signal to discontinue the process of forming the multisegment articles;
- generating a rejection signal for one or more multisegment articles corresponding to the deteriorated embossed portion.
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The present invention further relates to a combiner machine "M" (figure 2) or filter tip attachment machine (figure 1), in particular configured to carry out the method as described above.
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The machine "M" comprises at least two feed lines "L1", "L2" for feeding rod-shaped segments. At least one of the segments is a filter segment.
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In the case of the embodiment in figure 1, the two feed lines "L1," "L2" feed a double-length filter segment and a double-length aerosol generation segment, respectively.
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Preferably, double-length aerosol generation segments are fed by a maker machine "K" and then transferred to a cutting and spreading station "T" were they are cut so as to obtain aerosol generation segments of unitary length and mutually spaced apart.
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In the case of the embodiment in figure 2, instead, the feed lines "L1," "L2" feed respective filter segments.
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The machine "M" further comprises a conveyor drum 300 arranged downstream of the feed lines "L1", "L2". The conveyor drum 300 is a combiner drum or is arranged downstream of a combiner drum.
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The conveyor drum 300 is configured to feed a succession of rod-shaped segment groups. Each group comprises at least two segments.
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In the case of the embodiment in figure 1, the group preferably comprises at least two unitary-length aerosol generation segments deriving from the cutting and spreading station "T" and at least one double-length filter segment interposed between the two aerosol generation segments.
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In the case of the embodiment in figure 2, the group preferably comprises at least two filter segments.
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The machine "M" comprises a feed line for feeding a web "N" of material, in particular tipping paper, configured to feed the web "N" of material along a feed path "P".
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Along the feed path "P", the machine "M" then comprises an embossing unit 100 configured to make a succession of embossings on the web "N" of material.
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Preferably, the embossing unit 100 comprises at least one pair of embossing rollers 100a, 100b mutually meshing and appropriately spaced apart to make the aforesaid embossings.
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The machine "M" further comprises an applicator unit 400 configured to divide the web "N" of material into connecting strips (i.e., discrete portions) so that each connecting strip comprises at least one embossing.
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The applicator unit 400 is further configured to apply each connecting strip in a flag-like manner to a respective group of segments supported by the conveyor drum 300.
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The machine "M" further comprises a rolling unit 500 in which each connecting strip is enfolded around the respective group of segments to obtain a multisegment article. In such a situation, the multisegment article has the embossed connecting strip enfolded therearound.
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In the case of the embodiment in figure 1, the connecting strip is enfolded around the multisegment article which is formed by at least two single-length aerosol generation segments between which a double-length filter segment is positioned.
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In such an embodiment, downstream of the rolling unit 500, the machine "M" comprises a cutting station "C" in which double-length articles are cut so as to obtain articles of unitary length, each formed by at least one filter segment and one tobacco-generating segment.
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In the case of the embodiment in figure 2, the multisegment article consists of at least two filter segments enfolded by the connecting strip.
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Preferably, even in the case of the embodiment in figure 2, downstream of the rolling unit 500, the machine "M" comprises a cutting station "C" to cut the multisegment articles.
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The machine "M" further comprises at least one inspection module 200 comprising a laser detector 201 and configured to detect at least one embossed portion of one or more of the embossings.
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Preferably, the laser detector 201 is a 3D laser scanner.
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According to a possible embodiment, the at least one inspection module 200 is arranged along the feed path "P" of the web "N" of material. Alternatively, the at least one inspection module 200 is arranged downstream of the rolling unit 500.
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Alternatively, the machine "M" comprises a first and a second inspection module 200 each comprising a respective laser detector 201. The first and second inspection modules are located along the feed path "P" of the web "N" of material and downstream of the rolling unit 500, respectively.
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The machine "M" then comprises a processing unit "U" configured to reconstruct a virtual 3D model of the embossed portion, based on the detection of the inspection module 200 (or on the detections of the first and second inspection modules).
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The processing unit "U" is further configured to process the 3D model generating at least one signal identifying one or more of the following conditions:
- embossing of quality conformant or non-conformant with a reference quality for the current process;
- embossing correctly or incorrectly positioned;
- embossing of a type conformant or non-conformant with a type of embossing expected for the current process.
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Preferably, the processing unit "U" processes the 3D model to determine at least one dimensional or positional parameter of the embossing.
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In such a situation, if the derived identification signal identifies the conformant or non-conformant quality condition, the parameter is a dimensional parameter of the embossing, in particular the embossing height.
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Alternatively, in such a situation, if the signal identifies the condition of correctly or incorrectly positioned embossing, the parameter is a positional parameter of the embossing.
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In particular, the inspection module 200 detects one or more signs and/or markings and/or end edges of the web "N" of material so that, during the process by the processing unit "U" of the 3D model, the determination of the condition of correctly or incorrectly positioned embossing occurs by determining the position of the embossed portion with respect to the one or more signs and/or markings and/or end edges.
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According to a possible embodiment, when the processing unit "U" processes the 3D model and generates the at least one identification signal, such a signal identifies the conformant or non-conformant type. In such a situation, in order to determine if the type is conformant or non-conformant, a comparison of the 3D model, or of one or more of the projections thereof, with a reference 3D model or reference image(s) is made during the process by the 3D model processing unit "U".
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The present invention achieves the intended objects by eliminating the drawbacks of the prior art.
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In particular, the method of the invention allows performing accurate, reliable and non-invasive (without contact with the web of material or articles) check of the embossing conformance.
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The method of the invention allows simultaneously checking qualitative, dimensional and positional aspects of the embossing.
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The method of the invention allows significantly decreasing defective articles.
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The machine of the invention is efficient and reliable.