EP3148353B1

EP3148353B1 - Method and apparatus for production of composite rods for smoking articles

Info

Publication number: EP3148353B1
Application number: EP15732397.3A
Authority: EP
Inventors: Antonella Giannini; Alberto Monzoni
Original assignee: Montrade SpA
Current assignee: Montrade SpA
Priority date: 2014-05-26
Filing date: 2015-05-22
Publication date: 2018-06-20
Anticipated expiration: 2035-05-22
Also published as: WO2015181694A1; EP3148353A1

Description

Field of the invention

The present invention relates to methods for production of composite rods for the tobacco industry (such as cigarette filters or cigarette-substitute smoking articles) of the type comprising the steps of:

providing a plurality of segments longitudinally aligned with each other, and
wrapping a web of wrapping material (typically paper) around said aligned segments and causing it to adhere thereto with the aid of adhesive material interposed between said web and said segments.

In a composite cigarette filter, whether it is of a combined type (i.e. having filter segments which are all in contact with each other) or of the type including air recesses, the filter segments can be made of different materials (such as cellulose acetate and/or cellulose acetate impregnated with carbon particulate) and further they may be either of the "wrapped" type, i.e. each provided with its own paper wrapping, which is then covered by said wrapping web, or they may be of the "non-wrapped" type in which case the wrapping web enters into direct contact with the surface of the material constituting the filter segments.
Different types of apparatus are known in the art for producing cigarette filters of the above described type (see for example document US-A-3 131 612 and document WO2011/107854 A1 of the same Applicant, or also document EP 1 913 824 A1 ).
In known apparatus, once a desired sequence of filter segments has been obtained, these segments are caused to advance in an aligned condition along a longitudinal direction, until they are deposited in sequence above the wrapping web, which also is caused to advance continuously in the same longitudinal direction. Also according to the known art, on the web face which is to enter into contact with the filter segments adhesive material is preliminary deposited. The apparatus comprises a paper web wrapping station, arranged downstream of the area at which the filter segments are received on the web. At this station the paper web is guided so as to be laterally wrapped around the filter segments while adhering thereto. Usually at this station a further application of adhesive material is provided between the overlapped edges of the paper web wrapped around the filter segments.
However, in the known methods, adhesion between the paper web and the filter segments is not always found to be sufficiently safe, particularly in the case of non-wrapped filter segments. In the case of insufficient adhesion there is the risk that the filter segments on which the web does not adhere may escape out of the filter during use of the cigarette. This drawback is particularly heavy, since the non-wrapped filter segments are positioned at the end of the filter which is to be located close to the mouth of the user (for example a filter may comprise two segments 10 mm long and one terminal segment 7 mm long) so that if they come out from the filter they may cause the risk that the user swallows them or even remains stifled.
The solutions known in this field include the deposition of adhesive material on the inner face of the wrapping web, by spreading or spraying. The adhesive material is typically PVA and/or a hot-melt adhesive. The paper web on which the adhesive material is preliminarily applied is able to adhere efficiently to wrapped filter segments due to that a contact paper-to-paper is obtained. On the other end, the adhesion is less efficient for segments of the non-wrapped type, wherein the web paper is in direct contact with the material constituting the filter segments (such as cellulose acetate). In this case the grip coefficient is dramatically reduced. This drawback is worsened by that non-wrapped filter segments often have an irregular surface with wrinkles which are formed on the filter segment by nylon conveyor belts which are provided in the area upstream of the apparatus. The presence of this surface irregularities involves that the adhesive material spread on the web paper has a grip only at some areas of the filter segments, thus dramatically reducing the total adhesion to the wrapping paper.
This drawback is worsened by that the irregular surface of the non-wrapped filter segments causes at least a partial removal of the adhesive material from the face of the paper web due to a scraping action caused by the relative movement between the segment and the web which takes place temporarily during the step in which the filter segment is received above the web.
Similar problems are encountered for filter segments made of plastic materials.
In order to overcome this drawback there is a tendency to increase the quantity of adhesive material applied on the wrapping web, with a resulting contamination of the production process and a reduction of the efficiency of the apparatus. Furthermore, an excessive quantity of adhesive material causes a bad taste of the cigarette, which is perceived by the user.
Similar problems may be encountered for example also with rod segments constituting new generation smoking articles, to be used as cigarette substitutes, which operate according to the principal of inhaling heated tobacco rather than burnt tobacco as in conventional cigarettes. These smoking articles are constituted by an assembly of segments of various materials, including a heat generating segment and a tobacco segment.

Object of the invention

The object of the invention is that of solving the above indicated drawbacks.
More in general, the object of the invention is that of improving the efficiency of the adhesion of the wrapping web over the segments constituting a composite rod for smoking articles, whatever is the structure and the composition of the rod (such as a cigarette composite filter or a cigarette-substitute smoking article) and in particular whatever is the type of segments (such as wrapped or non-wrapped filter segments) of which it is made.

Summary of the invention

In view of the achieving the above indicated object, the invention provides a method according to claim 1 for producing composite rods for smoking articles, comprising the steps of:

- providing a plurality of rod segments, and
- wrapping a web of wrapping material along said segments and causing it to adhere thereto with the aid of adhesive material interposed between said web and said segments,

Therefore, according to the invention, the adhesion of the wrapping web over the segments is obtained after that adhesive material has been applied directly on the segments.
In the simpler embodiment of the present invention, it may be provided that the adhesive material is applied only on the segments and not also on the wrapping web, the application on the wrapping web being what is made in the prior art.
However, preferably the adhesive material is applied directly on the segments and also on an inner face of the web which is to enter into contact with said segments. The adhesive material is applied on the segment surface and on the inner face of said web, at positions such as to obtain adhesion of the web on the segments by contact of the adhesive material applied on the segments with the adhesive material applied on the web (glue-to-glue contact).
In the case of filter segments of the non-wrapped type, the adhesive material deposited directly on the filter segments covers at least partially the surface irregularities so as to give rise to a uniform surface, which insures a good adhesion. This is the reason why the invention is able to solve the problem also in the case in which the adhesive material is applied only on the filter segments.
Further in the case of the embodiment in which the adhesive material is applied also on the wrapping web, the invention provides the further advantage that by covering the surface irregularities of the non-wrapped segments, which is obtained by applying adhesive material directly on the filter segments, the above described scraping action causing a removal of the adhesive material from the wrapping web is avoided.
Finally, as already indicated in the case of the embodiment which provides application of adhesive material both on the segments and on the paper web, the adhesion is improved since a glue-to-glue contact is accomplished rather than a glue-to-cellulose acetate contact. In the case of this embodiment, the wrapping web may also be of the type which is already provided with a layer of glue.
In one embodiment of the invention, the adhesive material which is applied on the filter segments is preliminarily added with dyes and/or flavours.
The invention also provides the apparatus able to carry out the above described method, according to what is indicated in claim 8.

Description of preferred embodiments

Further features and advantageous of the invention will become apparent from the following description with reference to the annexed drawings, given purely by way of non limiting example, which shows some embodiments of the invention in the case of application to cigarette composite filters. In these figures:

figure 1 is a perspective view of a detail of an apparatus for production of cigarette filters according to the prior art,
figures 1A, 1B are cross-sectional views of a filter segment, during and after wrapping of the paper web, according to the solution of figure 1,
figure 2 shows the device of figure 1 modified according to a first embodiment of the present invention,
figures 2A, 2B are views in cross-section of a filter segment, during and after wrapping of the paper web, according to the solution of figure 2,
figure 3 shows the device of figure 1 modified according to a second embodiment of the present invention,
figures 3A, 3B are views in cross-section of a filter segment, during and after wrapping of the paper web, according to the solution of figure 3.

The annexed drawings refer to embodiments of the invention for the case of an application to cigarette composite filters. It is to be noted however that the invention is applicable to the production of composite rods for smoking articles of any type, including new generations smoking articles, to be used as cigarette substitutes, comprising segments in different numbers and different materials wrapped within a wrapping web.
In figure 1, reference numeral 1 generally designates a portion of an apparatus for production of cigarette filters in which a plurality of filter segments A (of the wrapped type) and B (of the non-wrapped type) are fed in sequence in a longitudinal direction X and deposited on a paper web W which also is caused to advance continuously along the same direction X.
The annexed drawings do not show the means which are used for causing the advancing movement of a paper web W nor the means for feeding the filter segments A, B on the paper web W. These means can be made in any known way, for example according to what is described and shown in document WO 2011/107854 A1 of the same Applicant.
In the specific illustrated example, the paper web W is fed in a vertical direction along a first run 2, after which it is re-directed in a horizontal run 3 by engagement on a cylindrical support 3a. The horizontal run 3 of the paper web W receives thereon the aligned filter segments A, B which are caused to advance in the longitudinal direction X of the horizontal run 3 of the paper web W.
According to the prior art shown in figure 1, upstream of run 2 there is arranged an adhesive material applicator device 4 adapted to form on web W, as a result of the movement of the web, one or more longitudinal stripes G (in this specific case two stripes G are shown - see also figure 1A) arranged longitudinally at the centre of web W. The adhesive material G is used for causing the paper web W to adhere on the filter segments A, B, which are deposited thereon. Downstream of the area at which the web W receives the filter segments A, B there is provided a wrapping station WS, with guiding means of any known type (not shown) which cause bending and wrapping of W laterally around the filter segments A, B. Web W is thus wrapped around segments A, B and held thereon by the adhesion effect due to the adhesive material G (which usually is PVA or a "hot-melt" adhesive).
Wrapping is completed by application of a further quantity of adhesive material F (see figure 1A) between the overlapped edges of the bent and wrapped web W, with the aid of a further adhesive material applicator 5, which is arranged at the wrapping station WS.
As indicated in the foregoing description, the above described prior art ensures a satisfactory adhesion between web W and the filter segments only in the case of segments A of the wrapped type. With segments B of non-wrapped type, the above discussed drawbacks are instead encountered.
Figure 2 shows a preferred embodiment of the present invention, in which the system still includes the applicator device 4 for depositing strips G of adhesive material on web W, but in addition thereto it also includes one or more adhesive applicator devices 6 (in the illustrated example two applicator devices 6 are provided) adapted to deposit adhesive material directly on each filter segment A and/or B. In the illustrated example, the applicator device 5 at the wrapping station WS is also present. The adhesive material is applied directly on the filter segments so as to cover at least partially the irregularities of the surface of the non-wrapped filter segments, which already involves an improvement in the final adhesion effect.
The applicator devices 6 are at a fixed position and deposit longitudinal strips of adhesive G' on the surface of filter segments A, B as a result of a movement of segments along direction X. In the illustrated example, as indicated, there are provided two applicator devices 6, positioned angularly spaced from each other around the filter segments which are advancing on the web.
As visible in figure 2A, the strips G' of adhesive material deposited on the filter segments and the strips G of adhesive material deposited on web W are positioned in such a way as to come in contact with each other when the web W is wrapped around the segments. In this manner, a glue-to-glue contact is obtained which ensures a further safe and efficient adhesion also with filter segments of the non-wrapped type. Apart from the improvement in adhesion due to the glue-to-glue cooperation, a further beneficial effect is obtained deriving from that the surface irregularities of the non-wrapped segments are covered by the adhesive strips G', which prevents the scraping action causing removal of the adhesive material from the paper W, when segments A, B have a movement relative to the web in the stage of deposition of the segments on the web.
The adhesive material can be any adhesive material of the prior art, such as PVA or hot-melt adhesive.
The paper web W may be of the type which is already provided with a layer of adhesive, in which case the adhesive material applicator device 4 or 5 is not necessary.
Figure 3 shows a simplified embodiment, which is still advantageous, in which the adhesive material is applied only on filter segments A, B while no adhesive is deposited on the web W, so that the applicator device 4 is eliminated. For the rest, this embodiment is identical to that of figure 2.
As already indicate in the foregoing, in both embodiments of figures 2, 3, the adhesive applicator device 5 is present, for depositing a layer of adhesive which enables a direct bond between the overlapped edges of the web W wrapped over the filter segments.
The adhesive applicator devices 6, similarly to applicator devices 4, 5, can be made in any known way. In particular, it is possible to provide applicator devices adapted to spread the adhesive material on the filter segments or spraying applicator devices. The detailed of construction of the applicator devices are not shown herein since, as indicated, they can be made in any known way and also because the elimination of these details from the drawings render the latter simpler and easier to understand. The configuration, the number and the arrangement of these applicator devices can be varied and is determined by the experts depending upon specific characteristics of the filter segments and the web for wrapping the filter segments.
It is well understood that, although in the present description the advantages of the method and the apparatus according to the invention have been discussed with reference to obtaining an improved adhesion of the paper web to non-wrapped filter segments, the invention is of a general application and can be used advantageously with any type and configuration of filters and therefore also in the case in which all segments are of the wrapped type.
In an embodiment of the invention, before that the adhesive material is applied on said segments, it is preliminary added with dyes and/or flavours.
Naturally, while the principle of the invention remains the same, the details of construction and the embodiments may widely vary with respect to what has been described and illustrated purely by way of example, without departing from the scope of the present invention.
It is in particular to be noted that the invention is applicable to any type of composite rod for a smoking article including a plurality of rod segments enclosed within a wrapping web, with any number, structure, material and shape of the rod segments.

Claims

Method for the production of composite rods for smoking articles, comprising the steps of:
- providing a plurality of rod segments (A, B), and

- wrapping a web (W) of wrapping material around said segments, and causing it to adhere thereto with the aid of adhesive material (G, G') interposed between said web (W) and said segments (A, B),
characterized in that before wrapping said web (W) around said segments (A, B) adhesive material (G') is applied directly on the surface of at least some of said segments (A, B).
Method according to claim 1, characterized in that at least some of said segments (B) are segments which are not wrapped within a respective wrap, and in that the adhesive material (G') is applied directly on said non-wrapped segments (B) so as to cover at least part of the surface irregularities of said segments.
Method according to claim 1, characterized in that the adhesive material applied directly on the segments (A, B) is applied so as to define one or more longitudinal strips on the surface of the segments.
Method according to claim 1 , characterized in that before winding said web (W) around said segments (A, B), adhesive material (G) is applied also on an inner face of the web (W) which is intended to come into contact with said segments (A, B).
Method according to claim 4, characterized in that the adhesive material (G, G') is applied on the surface of the segments (A, B) and on the inner face of said web (W), in such positions as to obtain bonding of the web (W) on the segments (A, B) by contact of the adhesive material (G') applied on the segments (A, B) with the adhesive material (G) applied on the web (W).
Method according to any of the preceding claims, wherein said segments (A, B) are advanced one after the other and deposited on said wrapping web (W) while the latter is also advanced in a same longitudinal direction (X) to a winding station, where said web (W) is guided so as to be laterally wrapped around said segments (A, B) while moving forwardly, characterized in that the adhesive material (G') is applied directly on at least some of said segments (B) by means of one or more applicator devices (6) arranged at a fixed position upstream of said wrapping station, so that dispensing of adhesive by each applicator device during the movement of the segments (A, B) gives rise to a longitudinal strip of adhesive over the segments (A, B).
Method according to any of the preceding claims, wherein before being applied on the filter segments (A,B) the adhesive material is preliminarily added with dyes and/or flavours.
Apparatus for implementing a method according to claim 1, in which said plurality of rod segments (A, B) are advanced one after the other and deposited on said wrapping web (W) that is advanced in a longitudinal direction (X) towards a wrapping station, where said web (W) is guided so as to be laterally wrapped around said segments (A, B) while moving forwardly, and in which at least one applicator device of adhesive material (G, G') is provided, for bonding the web (W) around said segments (A, B),
said apparatus being characterized in that said applicator device (6) is adapted to apply adhesive material directly on the surface of at least some of said segments (A, B) before that said web (W) is wrapped around said segments.
Apparatus according to claim 8, characterized in that said adhesive applicator device is located upstream of said web wrapping station (WS), in such a way that the delivery of adhesive from the applicator device (6) during the movement of the segments (A, B) gives rise to a longitudinal strip of adhesive on the segments (A, B).
Apparatus according to claim 9, characterized in that there are provided more applicator devices (6), adapted to apply adhesive material directly on the segments (A, B) and located at angularly spaced apart positions relative to each other.
Apparatus according to claim 8, characterized in that it further comprises an applicator device (4) of adhesive material, positioned to apply adhesive material also on said web (W) before said web (W) receives said segments thereon.
Apparatus according to claim 8, characterized in that at said wrapping station a further adhesive applicator device (5) is arranged, for
bonding overlapped edges of the web (W) when this is wrapped around the segments (A, B).