METHOD AND MACHINE FOR DETECTING AT LEAST ONE PROPERTY OF ARTICLES OF THE TOBACCO INDUSTRY HAVING AN AT LEAST PARTLY METALLIC COATING

Technical field

This invention relates to a method and a machine for detecting at least one property of articles of the tobacco industry having an at least partly metallic coating.

More specifically, the object of this invention is to inspect a semi-finished product of the tobacco industry consisting of a continuous rod wrapped in a tube of wrapping material, where the wrapping material is at least partly metallic. Background art

In many different situations in the tobacco industry, it is necessary to wrap a suitable semi-finished product in a wrapping material to make a continuous rod which, at later stages in the production process, is divided into separate segments to form the finished product to be made.

A strongly felt need in the industry is that of being able to efficiently check some of the properties of the semi-finished product, such as weight or density, so as to ensure that the production process of the rod, and ultimately of the finished product, complies with one or more quality parameters associated with the properties measured.

This need is normally satisfied by taking measurements of the rod after the rod has been formed; that is to say, when the semi-finished product has been wrapped completely in a web of wrapping material, in order to check that it has been filled correctly.

Measuring is performed by non-invasive and/or contactless measuring means such as sensors which use electromagnetic waves that are capable of passing through the continuous rod to measure one or more properties of the semi-finished product.

This solution is not, however, applicable in some production contexts: for example, if the web of wrapping material has metallic or at least partly metallized portions because these interfere with the measuring process by screening or distorting the radiation and thus preventing measurements from being taken correctly through the thickness of the semi-finished product.

This problem is all the more evident in the following example of machines for the production of continuous rods of tobacco.

Generally speaking, machines for making continuous rods of tobacco involve the use of a substantially vertical duct which is fed from below with a continuous flow of tobacco particles and at the top end of which there is a suction belt on which a continuous mass of tobacco is formed.

The suction belt is adapted to feed the semi-finished, continuous mass of tobacco along a predetermined path defined by the suction belt itself to a preforming device, which produces a continuous stream, and then to a station for forming a continuous tobacco rod where a web of wrapping material is wrapped around the continuous tobacco stream to form a continuous rod or cylinder of the tobacco industry, such as a cigarette rod, which is then cut into segments by a suitable cutting device.

More specifically, before being sent into the forming channel of the forming beam, the continuous stream of tobacco is suitably preformed and progressively compacted by the preforming device.

In this context, to ensure that the articles resulting from this production process have the right amount of tobacco in them, it is essential to measure the quantity of tobacco that is transferred into the infeed end of the forming channel.

It is obvious that the properties of the semi-finished product cannot be measured in the manner mentioned above if the paper used to wrap it comprises metal components.

In this specific context, machines are known in the prior art in which the detection station is disposed along the suction belt.

This feature guarantees that the continuous mass of tobacco can be measured without interference from metallic components applied to the web of wrapping material.

The Applicant has found, however, that this solution has considerable operational disadvantages which make it very inefficient in the performance of its functions.

In particular, this solution is not capable of providing an accurate measurement of the quantity/weight of the mass of tobacco which is transferred to subsequent production steps because some of the tobacco measured continues to be held by suction on the suction belt and falls off the belt by gravity or on account of the mechanical vibrations before being actually transferred to the processes downstream.

For this reason, even a measurement that indicates a correct amount of tobacco might result in a finished product that is not properly filled.

The material held by the suction belt is, in effect, a "suspended" mass and produces a level of uncertainty which negatively affects measurement precision.

Generally speaking, this problem also affects other tobacco industry production processes in which a continuous rod is formed by wrapping a semi-finished product, such as a mass of tobacco fibre, a stream of filter material, a uniform or non-uniform succession of segments of filter material, of aerosol-generating material or of flavour-generating material, or a stream of homogenized or regenerated tobacco, in a web of wrapping material comprising metallic particles.

Aim of the invention

In this context, the technical purpose which forms the basis of this invention is to overcome at least some of the above mentioned drawbacks of the prior art by proposing a method and a machine for detecting at least one property of articles of the tobacco industry having an at least partly metallic coating.

In particular, this invention has for an aim to provide a method and a machine for detecting at least one property of articles of the tobacco industry having an at least partly metallic coating, allowing the properties of the product to be correctly measured using an electromagnetic wave detector even when the products made are wrapped in material which is at least partly metallized or which contains metallic parts.

The technical purpose indicated and the aims specified are substantially achieved by a method and a machine for detecting at least one property of articles of the tobacco industry having an at least partly metallic coating, comprising the technical features set out in one or more of the accompanying claims.

This invention discloses a method of detection for articles of the tobacco industry having an at least partly metallic coating, comprising the following steps:

- forming a continuous rod of material of the tobacco industry, defined by a semi-finished product of the tobacco industry, wrapped in a tube defined by a web of wrapping material;

- detecting, with an electromagnetic detector, at least one property of at least one portion of the continuous rod; more specifically, the step of detecting is performed after the web of wrapping material has been completely wrapped around the semi-finished product;

- after the step of detecting, applying an at least partly metallic or metallized coating on the continuous rod in such a way as to make it unsuitable for combustion.

Advantageously, the present method allows ensuring that the properties of the semi-finished product being processed are correctly assessed by removing the risk, on the one hand, of metallic particles possibly interfering with the electromagnetic detector and, on the other, of obtaining false measurements on account of possible accidental variations which the semi-finished product might undergo immediately after being measured.

This invention also has for an object a machine for making a continuous rod of the tobacco industry and comprising a forming station, a detection station and a processing station.

The forming station is adapted to receive a web of wrapping material and a semi-finished product of the tobacco industry from respective feed means and comprises a forming beam on which the semi-finished product is placed on top of the web of wrapping material.

The forming station is configured to progressively wrap the web of wrapping material round the semi-finished product, thereby defining a continuous rod of material of the tobacco industry.

The detection station located downstream of the forming beam comprises at least one electromagnetic detector to detect one or more properties of the continuous rod.

The processing station is located downstream of the detection station and is configured to apply an at least partly metallic or metallized coating on the continuous rod.

Advantageously, the present machine provides an efficient and effective inspection tool for accurately assessing the structural integrity and inherent properties of the semi-finished product being processed, thus guaranteeing that the end product made using that semi-finished product attains an optimum quality level.

The dependent claims, which are incorporated herein by reference, correspond to different embodiments of the invention.

Brief description of the drawings

Further features of the invention and its advantages are more apparent in the non-limiting description below, with reference to a preferred but non exclusive embodiment of a device for inspecting smoking articles, as illustrated in the accompanying drawings, in which:

- Figure 1 is a schematic view of a machine suitable for implementing the method of this invention.

Detailed description of preferred embodiments of the invention

The numeral 100 in the accompanying drawings denotes in its entirety a machine for making at least one continuous rod of the tobacco industry. The machine 100 comprises a forming station 10, adapted to receive a web of wrapping material 1 1 from means for feeding the web of wrapping material 1 1 and a semi-finished product 12 of the tobacco industry from means for feeding the semi-finished product, located preferably upstream of the forming station 10.

The forming station 10 in turn comprises a forming beam 13 on which the semi-finished product 12 is placed on the web of wrapping material 1 1 , preferably to rest thereon.

In the context of this invention, the semi-finished product 12 may comprise a continuous stream of tobacco fibre, a stream obtained by crimping a web of tobacco, a stream of filter material, of aerosol-generating material or of flavour-generating material, or more generally speaking, a preferably continuous stream intended to be wrapped in the web of wrapping material 1 1 .

In other words, the forming station 10 is configured to receive the web of wrapping material 1 1 and the semi-finished product 12 in such a way that these are fed together to the forming beam 13, specifically with the semi finished product 12 placed on top of the web of wrapping material 11.

The forming beam 13 is configured to progressively wrap the web of wrapping material 1 1 round the semi-finished product 12 to define a continuous rod "B" of material of the tobacco industry.

It is stressed that the web of wrapping material 1 1 is made of materials that do not in any way generate any interference, distortion or noise in the electromagnetic signals used to inspect the properties of the semi-finished product 12, even after the latter has been wrapped completely in the web of wrapping material 11. The machine 100 also comprises a detection station 20 located downstream of the forming beam and comprising at least one electromagnetic detector 21 to detect one or more properties of the continuous rod "B".

By "property" is meant one or more features of interest, depending on the type of filling material being measured.

These properties may comprise, for example, those in the following, non- exhaustive list: weight, density, humidity, correct inclusion of additional elements.

The term "electromagnetic detector" 21 is used to denote any detector capable of performing a non destructive measurement through the thickness of the semi-finished product 12 using electromagnetic waves, specifically electromagnetic waves whose frequency is such as to be susceptible of interference from, or to be masked/distorted by, interaction with metallic particles.

For example, the electromagnetic detector 21 is a microwave detector operating at a wavelength of between 10 ⁹ and 10 ¹² Hz.

Preferably, the detection station 20 is located immediately downstream of the forming station, that is to say, without other processing units being interposed between them.

The machine 100 also comprises a processing station 30 configured to apply an at least partly metallic or metallized coating on the continuous rod "B".

More specifically, the processing station 30 is located downstream of the detection station 20 and is thus configured to receive the continuous rod "B" therefrom and to apply the coating on the rod.

In other words, the machine 100 comprises the forming station 10, the detection station 20 and the processing station 30 in sequence.

The forming station 10 receives the web of wrapping material 1 1 and the semi-finished product 12 and, by means of the forming beam 13, wraps the web of wrapping material 1 1 completely round the semi-finished product 12 to make the continuous rod "B" which is then fed into the detection station 20.

In the detection station 20, the electromagnetic detector 21 performs a non-destructive measurement on the continuous rod "B" to detect/measure one or more of its characteristic properties and then sends it on to the processing station 30.

Lastly, in the processing station 30 another coating, which is at least partly metallic or metallized, is applied on the continuous rod "B".

Advantageously, the machine 100 for making at least one continuous rod of the tobacco industry of this invention allows overcoming the drawbacks of prior art devices because it can accurately and precisely measure the properties of the continuous rod "B" without the risk of the measurement being influenced or distorted by the presence of metallic particles and performing the measurement only after it is certain that the semi-finished product 12 will not undergo unwanted/unpredictable variations.

Preferably, the processing station 30 is located immediately downstream of the detection station 20, that is to say, without other processing units being interposed between them.

It is not, however, excluded that the processing station 30 and the detection station 20 may be separated from each other by the presence of further processing units of the tobacco industry adapted to subject the continuous rod "B" to further processes before the coating is applied by the processing station 30.

For example, the detection station 20 and the processing station 30 might be separated from each other by an intermediate processing unit configured to cut the continuous rod "B" into a plurality of segments which are then fed into the processing station 30 where the coating is applied on each individual segment.

In a possible preferred embodiment, illustrated in the accompanying drawing, the processing station 30 is adapted to receive a web of an at least partly metallic or metallized overwrapping material 31 from means for feeding the web of overwrapping material and the continuous rod "B" from the detection station 20.

The processing station 30 also comprises a forming beam 32 on which the continuous rod "B" is placed on the web of overwrapping material 31 and which progressively wraps the continuous rod "B" in the web of overwrapping material "31 ".

In other words, in this particular embodiment, the processing station 30 performs a function similar to that of the forming station 10 in that it wraps the semi-finished product 12 in a wrapping material, specifically a second web of overwrapping material 31 which is at least partly metallic or metallized.

As a result, the forming station 10 and the processing station 30 are provided with respective forming beams 13, 32 which, as shown in detail in Figure 1 , may be adjacent to each other and separated only by the detection station 20 so that the latter receives the continuous rod "B" immediately after the semi-finished product 12 has been wrapped completely in the web of wrapping material 1 1 and feeds the rod to the processing station 30 immediately after one or more of its characteristic properties have been detected.

In a further possible embodiment, the processing station 30 is a spraying station configured to spray an at least partly metallic or metallized varnish on the continuous rod "B" to coat the latter at least partly.

This invention also has for an object a method of detection for articles of the tobacco industry having an at least partly metallic coating.

The method comprises forming a continuous rod "B" of material of the tobacco industry; as described above, the continuous rod "B" is defined by a semi-finished product 12 of the tobacco industry, wrapped in a tube of wrapping material 1 1.

Once the continuous rod "B" has been formed, an electromagnetic detector 21 is used to detect at least one property of at least one portion of the continuous rod "B". It is stressed that the step of detecting is performed after the web of wrapping material 1 1 has been completely wrapped around the semi finished product 12.

After the step of detecting, an at least partly metallic or metallized coating is applied on the continuous rod "B" in such a way as to make it unsuitable for combustion.

In other words, the method disclosed herein allows dividing the process of wrapping the semi-finished product 12 into two or more distinct steps separate from the measuring process.

This technical feature ensures obtaining a precise and accurate measurement of the properties of the semi-finished product 12 because the measurement is performed before the metallic particles are applied, thus eliminating the risk of the metallic particles interfering with the electromagnetic detector 21 , and after wrapping in a first web of wrapping material 1 1 which does not interfere with measuring operations, thus substantially eliminating the risk of the semi-finished product 12 undergoing unwanted, unpredictable changes/variations after being measured.

The method of this invention is directed to performing measurements on semi-finished products of the tobacco industry such as: a mass of tobacco fibre, a stream of filter material, a uniform or non-uniform succession of segments of filter material, aerosol- or flavour-generating material, a stream of homogenized or regenerated tobacco.

The measuring process is performed by an electromagnetic detector 21 such as, for example, a microwave detector, preferably configured to operate between 10 ⁹ and 10 ¹² Hz.

Advantageously, use of the electromagnetic detector 21 makes it possible to obtain multiple data values of interest regarding the semi-finished product 12 being processed, as for example: weight, humidity, density and correct inclusion of additional elements in the semi-finished product 12. According to a first aspect of this invention, the metallic particle coating is applied on the continuous rod "B" immediately after performing the step of measuring it.

In other words, after being analysed with the electromagnetic detector 21 , the continuous rod "B" is immediately sent on to the next step of applying the at least partly metallic or metallized coating.

Alternatively, in another possible embodiment, the step of detecting is followed by a step of cutting the continuous rod "B" into a plurality of segments before the coating is applied.

In this embodiment, the coating is not applied on the continuous rod "B" but on each individual segment.

Advantageously, this invention achieves the preset aims and overcomes the above mentioned drawbacks of the prior art by providing the user with a method and a machine for detecting at least one property of articles of the tobacco industry having an at least partly metallic coating to guarantee correctly analysing the quality of the product being processed.