ITBO20110272A1 - DEVICE FOR THE TREATMENT OF FILTERING MATERIAL FOR SMOKE ITEMS. - Google Patents

Description

DESCRIPTION

of the industrial invention entitled: "Device for the treatment of filter material for smoking articles"

The present invention relates to a device for the treatment of filter material for smoking articles, in particular in the context of a machine for the production of cigarette filters.

According to what is known, the production of cigarette filters involves the processing of a filter material consisting of a continuous strip, for example of cellulose acetate, also known by the name of "tow", obtained from a bale of compressed filter material.

The strip is made to advance along a determined path through processing stations, at which it is subjected to longitudinal stretching and transverse opening operations and then impregnated with plasticising additives. According to what is known, the step of impregnating the strip takes place in correspondence with suitable devices applied to it which are able to invest the strip with a flow of plasticising material, in particular triacetin, which at the ordinary operating temperature and pressure of these devices is in the liquid state. .

The strip is therefore hit by a flow of liquid particles, in a predetermined quantity and size, so as to absorb the desired quantity of triacetin.

Downstream of the triacetin application station there is a station at which forming means operate a continuous cylindrical bead of filtering material which, at a wrapping station, is progressively wrapped in a continuous strip of paper material for forming of a continuous filter bug. Finally, a rotating cutting device separates the continuous rod into single filter pieces.

According to what is known, the triacetin applicator device comprises, along the path of the strip and below it, a tank containing a determined quantity of triacetin, fed from a tank by means of a pump.

The known devices applied have, inside the tank and partially immersed in the triacetin, a rotating brush which, rotating at full speed, produces a flow of drops of liquid capable of investing the cellulose acetate strip from below.

In further devices it is known the use of nozzles, which spray the advancing strip from below, taking the triacetin directly from the tank.

Furthermore, known devices can process more than one strip at a time, generally two strips which usually advance along two parallel paths in the same machine. In this case each strip receives the triacetin from its respective brushes or nozzles.

In this case, moreover, it is known to provide the closing lid of the tank with an upper wall inclined downwards, from upstream to downstream with reference to the direction of advancement of the strips. This upper wall is provided with a slight rib, or with an appendix defined by a small projection, which is arranged centrally, i.e. on a central plane of the tank, so as to direct the triacetin deposited on the internal surface of the lid towards a recovery zone in a longitudinal direction, ie in the direction of advancement of the strips.

In known devices, it happens that the strip does not completely intercept the flow. This part of the flow goes beyond the advancement plane of the strip and then falls, from above, onto the strip itself.

However, known devices, capable of solving the problem, have the considerable disadvantage of limiting the operation of the device itself to a single and single format of the strip of filtering material to be treated.

In other words, it is not possible to use the same device for the treatment of different formats of strips of filtering material. In this context, the object of the present invention is therefore to provide a device for the treatment of filter material for smoking articles which is free from the drawbacks described with reference to the known art.

The technical task and the specified aims are substantially achieved by a device for the treatment of filter material for smoking articles comprising the technical characteristics indicated in one or more of the attached claims.

Further characteristics and advantages of the present invention will become clearer from the indicative, and therefore non-limiting, description of a preferred but not exclusive embodiment of a device for the treatment of filter material for smoking articles as illustrated in the accompanying drawings, in which:

Figure 1 schematically shows a filter packaging machine for smoking articles comprising a device in accordance with the invention;

Figure 2 shows, in a schematic side view, a first variant embodiment of the device in accordance with the present invention;

Figure 3 shows, in a schematic side view, a second variant embodiment of the device in accordance with the present invention;

- figure 4 shows, in perspective view and with some parts removed to better highlight others, a first embodiment of the device;

- figure 5 shows, in perspective view and with some parts removed to better highlight others, a second embodiment of the device;

- figure 6 shows, in perspective view and with some parts removed to better highlight others, a third embodiment of the device;

- figure 7 shows, in perspective view and with some parts removed to better highlight others, a fourth embodiment of the device;

figure 8 shows, in perspective view, a detail of the device according to the present invention;

figure 9 shows, in perspective view, a second variant of the detail of figure 8;

- figure 10 shows, in perspective view, a third variant of the detail of figure 8;

- figure 11 shows a step of making the detail of figure 8;

- figure 12 shows a step of making the detail of figure 9;

- figure 13 shows a step of making the detail of figure 10;

- figure 14 shows, in perspective view and with some parts removed to better highlight others, a second detail of the device according to the present invention;

- figure 15 shows an enlarged detail A of figure 11.

With reference to the accompanying figures, 1 indicates as a whole a device for treating filter material for smoking articles in accordance with the present invention.

The device 1 is used in machines 2 for the production of filters for smoking articles, in particular cigarettes, substantially of the type illustrated in Figure 1.

These machines 2 comprise a storage 4 of filtering material, in which two masses 6 of filtering material are contained, of which only one is illustrated in figure 1. Respective wicks 8 are unwound from the masses 6 which are advanced, by means of guiding devices of the type known, to a station 10 for processing the filtering material.

In detail, the processing station 10 of the filtering material comprises at least one blowing device 12 of a known type, capable of transversely widening the wicks 8, transforming them into continuous strands 14 of a given width. Preferably, the processing station 10 comprises three blowing devices 12, located along supply lines 16 as illustrated in Figure 1. The processing station 10 also comprises a device 1 for treating the filtering material according to the invention, located downstream of the blowing devices 12 and receiving the aforementioned continuous strands 14 at the inlet, to provide for the plasticization of the aforementioned continuous strands 14 by adding a plasticising fluid.

The treated continuous strands 14 are subsequently advanced towards a roller transport device 18, adapted to receive the aforementioned continuous strands 14 at the inlet and convey them towards respective strands or strips 22 of previously gummed paper. In correspondence with the area in which the strands 14 reach the belts 22, the strands 14 are collected in beads by respective conical conveyors to assume, in a known way, a substantially cylindrical shape.

After having assumed the aforesaid substantially cylindrical shape, the cords obtained from the strands 14 are parallel to each other and are wound with the gummed paper tapes 22 to obtain respective rods 24 of filtering material, parallel to each other.

The worms 24 thus obtained are fed to a device 26 for controlling the quality of the worms 24, and subsequently to a cutting head 28, which is suitable for cutting the worms 24 transversely to obtain respective sequences of segments not illustrated.

The applicator device 1 for treating filter material for smoking articles according to the present invention will now be described in detail, in accordance with a preferred embodiment illustrated in Figure 2.

The device 1 comprises a tank 30, having a bottom 32 and an upper opening 34, for containing a plasticising fluid product, in particular triacetin.

At least one continuous strip 36, defined by the aforementioned continuous stream 14 of filtering material, is made to advance along a respective filter processing and packaging line 16. The strip 36 is advanced at the upper opening 34 of the tank 30.

In particular, the strip 36 is advanced above the upper opening 34 of the tank 30.

The device 1 also comprises means 38 for generating a flow of plasticising fluid directed towards the continuous strip 36 of filtering material.

The flow generating means 38 comprise, according to a first preferred embodiment variant, illustrated in Figure 2, a rotating brush 40 equipped with bristles 42.

The brush 40 is inserted inside the containment tank 30 and is partially immersed in the triacetin. With the rotation of the brush 40, the bristles 42 collect triacetin and by means of an abutment, not shown in the figure, which the bristles 42 partially interfere with during rotation, spray the triacetin towards the continuous strip 36.

In a further embodiment variant, shown in Figure 3, the generating means 38 comprise a set of nozzles 44 connected to the containment tank 30. By means of a pump, not shown, the triacetin is sprayed, through the set of nozzles 44, towards the strip continuous 36 of filter material.

In particular, the device 1 comprises shielding means 46 of the upper opening 34 of the tank 30. The shielding means 46 define an exposure window 48 of the strip 36 to the flow of plasticizing fluid.

The window 48 has fixed dimensions and smaller than the dimensions of the upper opening 34 of the tank 30. Furthermore, the width of the window 48 is substantially equal to the width of the strip 36.

Preferably, a window 48 with a width exceeding by excess the width of the strip 36 is made, so as to ensure a correct supply of triacetin, in particular on the lateral edges 110 of the strip 36, in the event of any misalignments to which the strip 36 may be subject during advancement.

Particularly, reference is made to misalignments that the strip 36 can be subjected in a direction substantially transverse to the direction of advancement D of the same.

Said shielding means 46 can be replaced according to size, that is, according to the width of the strip 36 of filtering material to be treated.

The shielding means 46 have different embodiments, all falling within the context of the present invention.

Furthermore, reference will be made to a device 1 for the simultaneous treatment of two continuous strips 36 of filtering material. For this reason, the possibility of using the device 1, according to the present invention, for a single and unique continuous strip 36 of filtering material should not be excluded.

According to a first variant embodiment, illustrated in Figures 4, 6 and 8, the shielding means 46 are defined by a plurality of elements 50 separated from each other. Each element 50 has respective upper walls 52, which are substantially coplanar with each other. The walls 52 are furthermore substantially parallel, or slightly inclined, with respect to a plane of lying of the advancing strip 36.

According to a second variant of figures 5, 7, 9 and 10, the shielding means 46 are, on the other hand, defined by a plurality of elements 50, which are connected to each other. Also in this case, each element 50 has respective upper walls 52, substantially coplanar with each other.

The elements 50 are in the form of a flat plate 54.

The element 50 is made, as shown in figures 8 and 11, starting from a substantially rectangular flat plate 54 which is folded at its ends 56 along respective fold lines 58.

The element 50 then, once folded, includes the aforementioned upper wall 52, and two side walls 60 defined by the folding of the aforementioned ends 56.

According to a first embodiment, illustrated in Figure 4, the shielding means 46 comprise a first 62 and a second 64 lateral element, and a third 66 element located in a substantially central position of the tank 30.

In this way, between the first element 62 and the third element 66, and correspondingly between the second element 64 and the third element 66, respective windows 48 for exposure of each strip 36 to the flow of plasticising fluid are defined. More precisely, a first exposure window 68 of a first continuous strip 36a is defined between the first element 62 and the third element 66; while a second exposure window 70 of a second continuous strip 36b is defined between the second element 64 and the third element 66.

In this first embodiment, each window 68, 70 is to be understood as the portion of the plane comprised between two adjacent elements 50 and with respect to which the upper walls 52 of each element 50 are coplanar with each other.

In a second embodiment, the shielding means 46, on the other hand, take the form of a single flat plate 54 having at least one closed notch 72.

As illustrated in Figures 9, 10, 12 and 13, the flat plate 54 has a closed notch 72 for each of the continuous strips 36. In other words, each closed notch 72 defines an opening 74, which in turn defines the window of exposure 48, of the respective strip 36, to the flow of plasticising fluid.

The notches 72 are substantially rectangular in shape and identical to each other.

In this second embodiment the elements 50, since they are connected to each other, can be identified as portions of the flat plate 54. For example, with particular reference to figures 9 and 12, a first 76 and a second 78 portion can be identified in the plate 54 lateral and a third central portion 80, corresponding, respectively, to the first 62 and to the second 64 lateral element and to the third central element 66.

The side walls 60 are here defined by two longitudinal bands 82 of the flat plate 54, identified by the respective folding lines 58, which are folded, precisely defining the side walls 60 of the elements 50. The side walls 60 result in this case joined together by the material of the plate 54.

Each element 50 has precise and set dimensions. In this way, once the elements 50 are mounted on the containment tank 30, each exposure window 48 has precise dimensions.

Furthermore, for this reason, the dimensions of the window 48 are fixed and not adjustable.

When the shielding means 46 are defined by elements 50 connected to each other, and therefore obtained from a single plate 54, it is instead the closed notch 72 which is suitably sized according to the width of the continuous strip 36 to be treated. Also in this case therefore, with the assembly of the elements 50, the dimensions of the window 48 cannot vary and are therefore fixed.

Furthermore, if the flow generating means 38 have the rotating brush 40, the device 1 comprises a central crosspiece 86 for supporting the rotating brush 40. The crosspiece 86 centrally supports the brush 40 by means of an appendix 88, which has a hole 90 for the passage of the brush 40 itself (figures 6 and 7).

Figure 6 illustrates a third embodiment of the shielding means 46, which comprise the first side element 62 and the second side element 64, and centrally the third central element 66 and a fourth central element 92. The third element 66 is placed between the first strip 36a and the central crosspiece 86, while the fourth element 92 is placed between the central crosspiece 86 and the second strip 36b.

Similarly to the second embodiment, figure 7 shows a fourth embodiment of the shielding means 46 in which each exposure window 48 is defined by a respective closed notch 72 of the flat plate 54.

In this case, given the presence of the crosspiece 86 supporting the brush 40, the shielding means 46 comprise the first side element 62 and the third central element 66 connected to each other through the respective side walls 60, and the second side element 64 and the fourth central element 92 also connected to each other through the respective side walls 60.

More precisely, with reference also to Figures 10 and 13, the shielding means are made starting from two flat plates 54, each having a single closed notch 72 and corresponding to only two elements 50 connected to each other.

The containment tank 30 also comprises lower support means 94 of the shielding means 46.

In particular, the support means 94 interact with the side walls 60 of the elements 50 of the shielding means 46.

According to a first preferred embodiment variant, illustrated in Figures 2 and 3, the support means 94 are defined by a duct 96, placed inside the containment tank 30 and having a first 98 and a second 100 side wall.

Precisely the flow of plasticising fluid flows inside the duct 96 in the direction of the continuous strip 36 of advancing filter material.

The first 98 and the second 100 side walls are preferably inclined to better accompany the flow of plasticizing fluid. The inclined walls 98, 100 also allow to delimit the flow of fluid to better direct it towards each advancing strip 36.

The duct 96 has a lower mouth 102 and an upper mouth 104. Preferably, the duct 96 has a section that diverges from the lower mouth 102 to the upper mouth 104. The lower mouth 102 faces the means 38 for generating the flow of a plasticizing fluid, while the upper mouth 104 faces the strip 36 of advancing filter material.

The shielding means 46 are inserted inside the duct 96. More precisely, the side walls 60 of each element 50 are shaped in such a way as to adapt to the inclination of the walls 98, 100 of the duct 96. In this way, with the insertion of the elements 50, and therefore the shielding means 46 in general, are supported by the side walls 98,100 of the duct 96. In particular, each element 50, supported by the walls 98,100 of the duct 96, reaches a stable position inside the duct 96 itself .

The elements 50 reach this placement position, below each continuous strip 36.

Therefore, more precisely, according to this variant embodiment, the lower support means 94 are defined by the side walls 60 of the elements 50 of the shielding means 46 and by the inclined side walls 98, 100 of the duct 96.

According to a second variant, not shown, the containment tank 30 comprises abutments, located on the side walls of the tank 30 itself or on the side walls 98,100 of the duct 96. Also in this case, the side walls 60 of the elements 50 of the shielding means 46 they interact, for example for support, with these findings. The elements 50 reach, also in this case, a stable placement position inside the duct 96, ensuring an optimal shielding of the plasticizing fluid flow.

An advantageous aspect of these embodiments is represented by the ease of positioning and assembly of the elements 50 and therefore of the shielding means 46 per se.

The replacement, in the event of a format change of the continuous strip 36 of filtering belt, or if the width of the strip 36 to be treated varies, is advantageously quick and simple, furthermore allowing a reduction in the format changeover times given the simplicity of execution.

The device 1 also comprises means 106 for aligning the strip 36 in advance with the said exposure window 48 (Figures 4-7).

Said alignment means 106 are defined by a plurality of pins 108 substantially perpendicular to the plane of lying of the strip 36a, 36b.

Precisely, the alignment means 106 are defined by a plurality of pins 108 located at the inlet of the device 1.

The alignment means 106 are further defined also by a plurality of pins 108 located at the output of the device 1 itself.

The pins 108 have the task of compensating for possible misalignments of the strip 36 that could occur during the advancement. These misalignments could in fact, as already said, prevent the strip 36 from correctly intercepting the flow of plasticizing fluid, thus creating on the strip 36 itself areas free of plasticizing fluid.

Each strip 36 to be treated is kept in alignment, by means of at least one pair of pins 108, which compensate for any misalignments, through contact with the lateral edges 110 of the strip 36 itself.

Each strip 36 is kept in alignment, at the entrance to the device 1, by means of the contact of its lateral edges 110, by a first pair 112 of pins 108.

In the same way, each strip 36 is kept in alignment, at the outlet of the device 1, by means of the contact of its lateral edges 110 with a second pair 11 14 of pins 108. The pins 108 are movable along a direction transverse to the direction D of advancement of the strip 36. This allows to register the alignment, precisely, with the exposure window 48 as a function of the format of the strip 36.

The pins 108 are partially inserted in a respective guide 16 and, in the case of changing the format of the strip 36, the pins 108 of each pair 112,114 are moved along this guide 116 to adjust their distance according to the width of the strip 36 to be treated.

Once the correct positioning has been achieved, the pins 108 are locked in this position by means of clamping means, not shown.

The pins 108 have a substantially cylindrical shape. Since the pins 108 come into contact with the lateral edges 110 of the strip 36, the pins 108 are made of a material having a low coefficient of friction in such a way as to avoid the damage of the strip 36 due to rubbing during its advancement. Likewise, the pins 108 can be freely rotatably mounted in the respective guides 116, so as to accompany, with their own rotation, the advancement of the strip 36.

Even the adjustment of each pair 112,114 of pins 108 is very simple, and therefore also allow a faster execution in case of format change.

The device 1 further comprises a lid 118 for closing the containment tank 30.

As shown in Figure 14, the lid 118 is placed above the tank 30 and between the first 112 and the second 114 pairs of pins 108.

Preferably, the containment tank 30 has, parallel to the direction D of advancement of the strips 36, a respective support strip 120 of the lid 118. The strip 120, in particular, maintains the lid 118 at a certain distance from the plane where the strip lies. 36, so as to allow free sliding of the strip 36 itself.

The lid 118 has internally, in correspondence with its internal surface 118a, at least one outflow element 122 for a possible deposit of plasticizing fluid.

The lid 118 also has an inclined upper surface 124, such as to make the section of the lid 118 converging along the direction D of advancement of the strip 36, so as to better facilitate the outflow of the deposited fluid.

During the generation of the flow, it may happen that part of the plasticising fluid, fed towards the advancing strip 36, may go beyond the plane of the strip 36 itself and therefore deposit on the internal surface 18a of the lid 118. In order to avoid possible fallout of particles of fluid on the strip 36, which would therefore define a flow of fluid greater than that necessary, the cover 118 has said outflow element 122 on the internal surface 118a.

As shown in Figure 15, the outflow section 122 consists of at least one rib or appendage 126, lying on a plane parallel to the direction D of advancement of the strip 36, capable of recovering and directing the particles of fluid deposited on the internal surface 118a of the cover 118, towards a fluid recovery zone Z.

Preferably the lid 118 is provided with a plurality of ribs or appendages 126 parallel to each other, so as to optimally direct the triacetin deposited on the internal surface of the lid towards the recovery zone Z.

Otherwise, the outflow element 122 can be made up of a plurality of grooves 128, obtained on the internal surface 118a of the lid 118, and these too can recover and direct the fluid particles towards the recovery area Z.

The recovery zone Z is located, according to what can be deduced from Figures 2 and 3, in correspondence with the front part of the containment tank 30, in proximity to the front pins 108.

In correspondence with this zone Z, the tank 30 has at least one drainage surface 130, inclined in the direction of the means 38 for generating the flow of plasticising fluid.

In particular, if more strips 36 are treated at a time, it is preferable to associate with each strip 36 respective drainage surfaces 130 of the recovered fluid, as illustrated in Figures 4 to 7.

Said drainage surfaces 130 receive the particles recovered from the outflow element 122 and pour them into the tank 30 in the direction of the fluid flow generating means 38.

The invention described above makes it possible to obtain a device for treating filter material for smoking articles which is capable of operating on different formats of the strip of filter material.

Furthermore, the invention guarantees effective protection of the strips and at the same time ensuring a correct supply of plasticising fluid.

Furthermore, the invention allows to reduce the format changeover times, given the ease of execution in the replacement of the shielding means.

The invention thus conceived is susceptible of evident industrial application; it can also be subject to numerous modifications and variations, all of which are within the scope of the inventive concept; all the details can also be replaced by technically equivalent elements.

Claims (14)

CLAIMS 1) Device for the treatment of filter material for smoking articles, comprising a containment tank (30) for a plasticising fluid product having a bottom (32) and an upper opening (34); at least one continuous strip (36) of filter material advancing along a respective processing and packaging line (16) of filters for smoking articles at the upper opening (34) of the tank (30); the device comprising generating means (38) for a flow of a plasticising fluid directed towards the continuous strip (36) of filtering material, characterized in that it comprises shielding means (46) of the upper opening (34) of the tank (30) defining an exposure window (48) of the strip (36) to the flow of the plasticising fluid, the window (48) having fixed dimensions smaller than the dimensions of the upper opening (34) of the tank (30) and of a width substantially equal to the width of the strip (36). 2) Device according to claim 1 characterized in that the shielding means (46) can be replaced according to the width of the strip (36) of filtering material to be treated. 3) Device according to claim 1 or 2, characterized in that the shielding means (46) are defined by a plurality of elements (50) separated from each other and having respective upper walls (52), substantially coplanar with each other. 4) Device according to claim 1 or 2, characterized in that the shielding means (46) are defined by a plurality of elements (50) connected to each other and having respective upper walls (52), substantially coplanar with each other. 5) Device according to claim 3 or 4 characterized in that each element (50) is in the form of a flat plate (54). 6) Device according to any one of the preceding claims characterized in that the tank (30) comprises lower support means (94) of the shielding means (46). 7) Device according to claim 6 characterized in that it comprises a duct (96), placed inside the containment tank (30) and having a first (98) and a second (100) side wall; the shielding means (46) being supported by the side walls (98,100) of the duct (96). 8) Device according to any one of the preceding claims, characterized in that it comprises means (106) for aligning the strip (36) in advance with the said exposure window (48). 9) Device according to claim 8 characterized in that the alignment means (106) are defined by a plurality of pins (108) substantially perpendicular to the plane of the strip (36). 10) Device according to claim 9 characterized in that the strip (36) is kept in alignment by at least one respective pair (112,114) of pins (108); said pins (108) defining the alignment of the strip (36) through contact with the lateral edges (110) of the strip (36). 11) Device according to claim 10 characterized by the fact that the pins (108) are movable along a direction transversal to the direction (D) of advancement of the strip (36), to adjust Γ alignment with the exposure window (48) according to the strip width (36). 12) Device according to any one of the preceding claims, characterized in that it comprises a closing lid (18) which has at least one plasticizing fluid outflow element (122) at its internal surface (118a). 13. Device according to claim 12 characterized in that the outflow relay (122) is in the form of at least one rib or appendage (126). 14) Device according to claim 12 characterized in that the outflow relay (122) is in the form of at least one groove (128) formed on the internal surface (118a) of the cover (118).