DE2343327A1 - FILTERS, IN PARTICULAR TOBACCO SMOKE FILTERS - Google Patents

Description

CIGARETTE COMPONENTS LIMITED, Friendly House, 21-24 Chiswell Street, London, E.C.1, England

Filters, in particular tobacco smoke filters.

The invention relates to the manufacture of filters and is directed in particular. To tobacco smoke filter elements. Preferably the invention is concerned with filter tips for cigarettes, although the products of the invention are general Can be used as filters, especially as tobacco smoke filters, Regardless of whether it is a cigarette, cigar, pipe or similar tobacco smoke filter, Da filter are of particular economic interest for cigarettes, the basic elements of the invention are based on production of filter cigarettes discussed.

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Various methods of manufacturing filters in connection with tobacco smoke products, _for example cigarettes, are already known, although the resulting products generally have several compartment parts. The most important property of a filter is its filtering effectiveness, that is, its ability to remove undesirable components from tobacco smoke. Filter efficiency is usually measured in terms of the percentage of Totally Milled Mass (TPM) that is removed from the smoke, although it also affects some percentages of gaseous components that the filter is also able to remove. While filter efficiency is probably the most important property of cigarette filters, it is necessary to compromise filter efficiency in known filters in order to give such filters other properties, such as waste, taste, hardness, appearance and cost, which play a role In the economic acceptability of such filters, for example, the cellulose acetate filters commonly used today exhibit relatively low filtering efficiency, although increased efficiency can be achieved either by increasing the density of the filter material or increasing the length of the filter element, but in both If there is a pressure drop across the filter that is too excessive and therefore unacceptable from an economic point of view. Although various proposals have been made for the manufacture of a filter having improved filtering properties, most of the improvements made so far have been economically acceptable because the resulting filters have adverse taste properties, so that the cigarettes provided with such a filter do not attract a large proportion of the smoking public addressed. Other disadvantages are the techniques and / or materials used in making such filters

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had to be applied, the cost being excessive rose.

High filtration efficiency is believed by the industry when 6Q56 and more of all particulate matter is removed. Cigarette filters having such properties have recently been produced in accordance with the teachings of TJS Patents 3,533,416, 3,599,646, and 3,648,711. However, the production of a cigarette filter with a somewhat improved filter efficiency without adversely affecting other desirable properties, for example pressure drop and the like, is economically interesting / aterial less material which _t the manufacturing cost is reduced economically is also important. it is extremely important that a verberserte filtration efficiency for a given value of the pressure drop is provided. Moreover, it is highly desirable method for the production of cigarette filters o. etc. to propose which are easily suitable for manufacturing the filter elements with a variety of properties which enable the manufacturer to select different features for these filter devices as required.

The present invention provides a smoke filter element consisting of an axially elongated, hollow outer member, an axially elongated inner member of filter material, which is disposed within the outer member, wherein an integral part of the inner member extends across the full diameter of the inner member in Form of an unfolded plug of filter material extends, while the outer surface of this integral part of the inner member is part of the inner surface of the outer

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Member opposite so that there is essentially an axial passage of the smoke over the area therebetween is prevented, and wherein at least one completely enclosed cavity is present, which is of the filter material of the inner member including the integral part. This cavity provides less resistance against the flow of smoke as the filter material and the smoke passing through the filter element from one end part of the inner member flows through to the other, passes through the cavity and flows through at least twice the filter material.

The drawings show in

Fig. 1 is an enlarged longitudinal section to show part of a device and a device for Manufacture of filter elements according to the invention with selected elements in alternating positions ■ are shown in dashed lines;

Fig. 2 is a schematic cross section for reproducing the storage of an additive in alternating cavities a filter rod in production;

3 shows a longitudinal section through a shape of a filter rod which can be produced according to the invention lets, whereby it can be seen how such a rod can be divided into individual. Filter elements to achieve with selected properties;

Fig. 4 is an enlarged perspective view, partially in cross section, showing a portion of a Filter cigarette with a filter element according to the invention, with some parts for better illustration are drawn broken open;

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FIG. 5 shows a longitudinal section through a modified embodiment of a filter element according to FIG Invention with a schematic representation of the path taken by the smoke in passage;

6 shows a section through the element according to FIG. 5 along the line 6-6 of FIG.

7 is an enlarged perspective view, in part in section through a further modified embodiment of a filter element according to the invention; and in the

8-14 are views of various filter elements which can be produced according to the invention, wherein result in different configurations for aesthetic or functional reasons.

Like reference characters refer to like parts throughout the several views of the drawings.

Before further discussing the specific procedures, facilities and products of the present invention, reference is made to the U.S. patents listed above, whose main subject is to be considered fully described here.

If one compares the drawings with the drawings of the U.S. Patent No. 3,637,447, it will be seen that Figure 1 of the accompanying drawings depicts part of an apparatus which modified in an extremely significant manner from the device of FIGS. 1 and 19 of US Pat. No. 3,637 '+47 has been. The remaining parts of the device according to the present invention as well as those used Techniques correspond completely to those according to US Pat. No. 3,6; "447. Since this is a publicly available

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Reference can be made to this patent specification can be taken without having to repeat the corresponding passages.

Although the products according to the present invention are preferably made from a continuous rope of cellulose acetate fiber material, the invention is not limited to the use of this material, ά & rnxt slight modifications that are obvious to the person skilled in the art, the fiber rope. Also from other materials, for example made of polyethylene, polypropylene and the like. Unwoven staple fibers such as those described in detail in U.S. Patents 3,297,041 and 3,552,400 can also be used. However, since cellulose acetate fiber ropes are the preferred material from an economic point of view, this material will be specifically addressed in the following description.

Referring to Fig. 1, part of a method of making filter elements in accordance with the present invention is entire generally designated by the reference number 20. Serving part contains an air nozzle 22, which runs along the path of the Filter material 24 is arranged, which runs to a first curing station 26.

Details of the construction of the nozzle 22 are basically the same as the similar element disclosed in US Pat 3 636 447 is designated by the reference numeral 14, so that a detailed description of this nozzle unnecessary.

The first curing station 26 is similar in structure the element 60 according to US Pat. No. 3,636,447, although this station is a bit more precise in the present drawings:

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geste3.lt is. Esp. contains this first curing station, which could also be referred to as the bonding zone, one generally cylindrical portion 23 and one flattened or conical entry part 30,

When air is introduced into the strand nozzle or air nozzle 22 through line 32 connected to a manifold 34 is connected, uro in the rope 24 in the direction of the ring To get there, steam or some other means that is able to activate the binding agent in the filter material is introduced through a line 36 into a distribution line 3S, from where this medium through a multitude of in the distance arranged openings 40 in the rope between the path of travel of the rope through the cylindrical part 28 of the binding zone 26 entry.

It can thus be seen that an elongated band of filter material 24 enters the rear end of the strand die 22 and a mandrel support 42 to form a generally hollow tubular member happens, which then moves further forward around a mandrel 44, which is actually inside the strand nozzle 22 is inserted and extends at least partially into the binding zone 26. If now the rope is out exits the front end of the strand nozzle 22, it is mixed with air which is supplied from the line 32. the Generate settings of the various elements of the strand die according to the instructions of US Pat. No. 3,636,447 a vsnturi-like opening at the outlet of the strand nozzle 22, so that the emerging rope explodes or puffs up, as shown at 46. An evenly random fluffy mass is created before the dew moves in the binding zone or curing station 26 arrives.

It should be noted that since the binder is in the

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fibrous rope during the passage through the strand die 22 is not yet activated, the final shape that is communicated to the rope, which consists of a large number of plasticized randomly arranged fiber links this point is not yet influenced.

Only when the rope comes into contact with a binding agent, in this case steam, do the fibrous links become of the filter material bound to one another at spaced-apart contact points, so that an elongated, smoke-permeable A strand is created which provides the labyrinth path for the smoke to pass through.

It can be seen that the heating and forming device for the binding zone 26 is designed so that the moving rope, which is generally strand-like in shape, with the steam as it passes through the cylindrical Part comes into contact. The application of steam to the fibrous dew in the aggregation leads to a softening of the dew fibers and the plasticizer contained therein and has the effect of evenly binding the fiber links of the rope to those spaced apart Place. By passing the steam into the dew under pressure in a limited area and preferably below At an angle to the longitudinal axis in a direction opposite to the direction of movement of the rope, the steam penetrates into the Thaws between the fibers and touches the fibers when they are gathered together. All of the fibrous limbs and the whole Placement materials are thus heated substantially uniformly, with a substantially uniform Binding to spaced-apart points of contact of the fibrous links takes place.

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In the absence of the dome 44, a smoke-permeable, generally cylindrical continuous strand produced as the rope passes through the first curing station runs. However, the presence of the mandrel 44 within the binding tongue 26 creates an annulus through which the filter material must go through, so that instead of a solid strand, one with an inner opening, i.e. a hollow strand is created.

According to the teaching of U.S. Patent No. 3,637,447, the product exiting the first curing station is actually a continuous hollow or ring element. Here the present invention now deviates from the teaching of the US patent mentioned away.

It can be seen in particular. From Fig. 1 that the mandrel 44 with devices 48 is provided, which back and forth the mandrel within its support element 42 and esp. act so that the front end portion 50 of the mandrel 44 between a first position, which extends at least as far forward of the path of the filter material 24 as the point at which the filter material contacts the binder comes, is, and moved back and forth to a second position, which is indicated by the dashed line 52 and is a distance back from that point.

The means performing the reciprocating movement can be of a simple mechanical construction shown in FIG is capable of moving the mandrel 44 back and forth along the axis of the processing machine. In the reproduced An embodiment that is intended merely as an exemplary embodiment is a handlebar 54 at one end 56 hinged to a bracket 58 carried by the rear of the mandrel 44. Besides, the

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Link articulated between its ends at 60 on a fixed support, not shown.

The other end of the link 54 carries a cam roller 62, which by a spring 66 is normally engaged with a Eccentric 64 is pressed.

If the mandrel 44 is in its foremost position, then the filter material 24 is in an annular space between the outer wall of the dome 44 and the inner wall of the cylindrical part 28 of the binding zone 26 is limited. As the filter material with steam or a similar binder comes into contact at this point, the fibrous limbs of the filter material become smoke permeable annular wall part 58 formed.

However, if the mandrel 44 is withdrawn on its return stroke to the position where the front end portion of the with the The position indicated by dashed lines 52 is then a part of the filter material in the transverse direction can be completely Spread over the binding zone before it comes into contact with the binding agent. This applies in particular if the Point 52 is selected so that it falls into the conical section 30 of the first curing station 26. In this way becomes a smoke permeable plug of bonded fibrous members 70 integral with the annular wall 68 in the part formed of the filter material, which is in contact with the binder during the forward movement.

Of course, the various elements for generating a forward movement of the filter material and a back and forth movement of the dome synchronized and laterally tuned so that the correct ratio results, depending on the desired radio

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functional properties of the product. However, this vote lies within the scope of the professional ability, so that it does not need to be discussed in detail.

It can thus be seen that the method according to the invention and the proposed device for its implementation allows the production of intermittent internal cavities that are completely closed and surrounded by the ring wall 68 and by front and rear plugs 79.

According to a preferred feature of the invention, the inner cavities can be completely or partially filled or one can fill selected cavities with an additional material, for example an absorbent, smoke-modifying material Material. For this purpose, the mandrel 44, as shown in Fig. 1, can be made hollow and one can Source 74 for this additional material in communication with the rear end of the mandrel 44 via a flexible conduit 76 bring. A preselected amount of additional material .terials insert through the mandrel into one or more selected cavities when the mandrel is on its return stroke moved backwards. Obviously, the mode of operation of the feed device for this additional material be coordinated with the manufacture of filter rods so that additive material in any desired amount in each or any cavity formed or only fed into selected, for example alternating cavities. In addition, the additional material can be small-grained Material, for example activated carbon or possibly. Act silica gel or other absorbent. An additive of this type is indicated generally by the reference numeral 78. One can also use a mixture of such materials and / or introduce liquid materials as long as this

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I **

Geraisch the properties of the manufactured filter rod not adversely affected.

The size of the cavities formed, the thickness of the annular wall, the extent of the plug between the cavities, the Use, the size of the load and the type of additives can be determined within the scope of the expert knowledge change easily. In addition, after the complete production of a filter rod, as will be explained in more detail later will be explained, this can optionally be divided at any point along its length, as for example is indicated in Fig. 3 by the dashed lines 80 in order to produce individual filter elements. Usually done however, separation of the filter rod only when it is wrapped in paper or the like, as is the case in US Pat 3 637 447 is described. However, it is important to be aware of it point out that filter elements with a single internal opening or with a plurality of internal openings or cavities can be produced, in the latter case one or more of these cavities with an additional material Can be filled to create filter elements that have any desirable combination of properties depending of the intended use.

The subsequent processing of the filter rod can be done accordingly following the teachings of US Pat. No. 3,637,447. Any desired device, for example the common Arrangement 70 according to the above-mentioned patent specification can be provided in order to feed the filter rod through the processing apparatus according to FIG. 1 of the present patent application draw. In addition, a subsequent curing station, as indicated at 114 in US Pat. No. 3,637,447 is to be provided, especially if the filter rod, as at 118 according to this patent specification, before hardening and conversion

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wrap is to be crimped as indicated at 146 and 152 in U.S. Patent 3,637,447.

During the wrapping process, it is important that a portion of the outer surface of one of the plugs 70 of the pilter strand be in constant circumferential contact with the inner surface of the wrapping material. This creates a sealed surface through which smoke cannot pass. For a better understanding of such an arrangement, reference is made to FIG. 4, where part of a filter cigarette is generally designated by the reference numeral 100. This filter cigarette contains a conventional tobacco rod 102, which is wrapped with cigarette paper 104 and connected to a filter element butting against one another in accordance with the principle of the invention, the filter element having the reference number 106. In the embodiment of the filter element shown in FIG. 4, the inner member, which is a cut-off part of the filter rod produced according to the invention according to FIG opposes the inner surface of the wrapping material 112 to form the aforementioned sealed area. Finally, a pointed paper 114 is indicated which connects the filter part with the tobacco part in the usual way. The ring wall of the filter element 106 can be seen at 116 , the inner cavity at 118. In the embodiment according to FIG. 4, one end of the filter element 106 is crimped. as described in U.S. Patent 3,637-447 to form a plurality of cruciform ribs 120 the outer or peripheral edges of which contact the inner surface of wrapping paper 112 to aid in centering the inner member within the outer member "

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Some configurations for the curved end of the filter element can be seen in FIGS. 8-14. In each In this case, only the shape of the crimping device needs to be changed in order to get to the desired shape, what again is a matter for the skilled person who does not have any further with regard to the design of the tools Teaching is required.

The filter devices according to the present invention can be used singly or doubly, and sometimes even in multiple units. Reference should be made to the explanations according to FIGS. 5 and 6, from which it can be seen that the filter rod is curved between a cavity, so that several independent cavities 122, 124 are formed, between which the crimped partition 126 is located Previous embodiments required the smoke to flow from one end of the filter element to the other in order to pass through the plug and into the interior cavity, which has less resistance to the smoke penetrating through than the filter material itself and then out again the filter element through the filter material, so that in each case the smoke at least twice should the filter material pass "in the model shown in Fig. 4 embodiment, a portion of the filter element is curved εο that an outer cavity is created in this case, a plurality of external cavities 128, the smoke having to pass through these cavities from the tobacco to the smoker's mouth.

In the embodiment according to FIG. 5, the breath passes the filter element four times if one takes into account that it flows through one of the end plugs _} thinly into the inner hollow space 122, through the filter material again into the outer hollow space 180, and back through the filter material into the Inner cavity 124 and finally through the filter material of the plug

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If

at the mouthpiece end of the filter element.

The changes to the above mentioned arrangements are only limited by the ingenuity of the processor and in no way deviate from the inventive principle, created according to the filter elements of infinite variety in terms of functional and aesthetic properties should be.

The embodiment according to FIG. 7 corresponds to the greatest possible extent the previously described embodiments with the exception that a plurality of outer in the longitudinal direction extending cavities 132 is provided with intermediate ribs 134 in the manner of a gear. Of course these cavities can not extend over the full length of the outer sides of the filter element, since it is necessary is, a continuous circumferential surface on one Manufacture the end of the filter element to create the required sealed area that allows smoke to pass through pushes the filter material through and prevents bridging. The cavities 132 increase the outer surface area of the filter element and thus create a greater possibility for the smoke over the length of the filter element it to get into the inner cavity, which in the embodiment of FIG. 7 with an absorbent, the Smoke modifying additive is filled.

It should be noted that there are two particularly important features for any embodiment of a filter element made in accordance with the invention. The first point to note is that it is primary purpose of the filter material is to remove undesirable constituents from the smoke passing through, or at least to reduce their proportion, and regarding the fibers or

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of the fiber part of the filter element, it is essential that the special small material or the solid phase components of the smoke are not impaired.

An effective reduction in the filter efficiency results when the smoke-permeable strand of filter material compressed or crimped and for this reason each filter element comprises in accordance with the present invention at least a portion of which is in the form of a smoke permeable uncurved plug, the outer surface this part at least partially represents the sealing surface with the wrapping material. By maximizing the uncrimped Part of the filter element, the filter efficiency is increased considerably, so that the filter material its main function can perform in an optimal way.

Another fundamental main feature of a filter element according to the present invention is the presence at least an inner fully enclosed cavity which is surrounded by the filter material. Until now it was not possible to create such an inner cavity ^ the filter material forming or delimiting the cavity being integral with the end parts and the annular or peripheral wall is between the end parts. In that it is possible to manufacture a filter element according to the invention that the inner cavity is completely surrounded with one-piece filter material that does not necessarily have to be curved must, or in another way to other material, for example by adhesive o. The like. Must be attached, results the highest possible filter effectiveness per unit length of the filter material.

The present invention thus enables manufacture

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a Piltereleraentes with increased filter efficiency for a given pressure drop, while all others desirable properties, especially with regard to cigarette filters, including an acceptable "taste", Appearance and reduced costs through simplicity in manufacturing techniques and equipment as well the reduction in the amount of filter material for a given effectiveness value is maintained.

It should be pointed out again that filter elements of the type specified, for example according to FIG. 2, as such with no subsequent crimping required by making a plug of smoke permeable Material can extend transversely from one end to the other of the filter element, with one if necessary absorbent, smoke-modifying additive during the manufacturing process is extremely simple Manner can be introduced that prevents the smoke from flowing over the additional particles, the gas phase efficiency of the end product is largely increased. A crimping can be used for special areas of application use to modify the appearance and mode of action of the filter material, in turn on the diversity of the proposals according to the invention with regard to the production and the end product is to be referred to.

Claims ;

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Claims (4)

I * P at enta η sayings Filter element, esp. Tobacco filter element consisting of an axially elongated era hollow outer Member, an axially elongated inner member made of filter material, which is arranged within the outer member with an integral portion of the inner member extending across the full diameter of the inner member in the form of a non-crimped plug of filter material, the outer surface of the one-piece part of the inner member faces a portion of the inner surface of the outer member and is substantially axial Prevents smoke from passing over the area in between, characterized by at least a completely enclosed Hohlrauru (118), which from the filter material (110, 116, 120) of the inner member (108) which contains the one-piece part (110), whereby the cavity (118) has a lower resistance to the Smoke flow or the like. Provides through the filter material and the smoke or the like through the filter element from one end portion of the inner member to the other through the cavity and flows through the filter material at least twice. 2. Filter element according to claim 1, characterized in that the cavity (118) is unfilled, 3. Filter element according to claim 1, characterized in that that a quantity of absorbent, smoke-modifying material (78) is accommodated in the cavity (118). 40981 2/0877 4. Filter element according to claim 3, characterized in that that the smoke modifying material (78) contains activated carbon. 5. Filter element according to one or more of the preceding claims, characterized in that the filter material consists of a cellulose acetate rope. 6. Filter element according to one or more of the preceding Claims, characterized in that parts of the outer surface of the longitudinal sides of the cavity (122, 124, Fig. 5) are spaced from the inner surface of the outer member, so that an outer cavity is formed, which is less Having resistance to the flow of smoke as the filter material, the flow of smoke passing through the filter material from one end portion of the inner link to the other end portion through both the outer and inner cavities and at least zv / eiraal leads through the filter material. 7. Filter element according to claim 6, characterized in that that integral parts (126) of the inner member extend across the inner member between the ends of the inner cavity extend and divide the inner cavity into at least two separate inner cavities (122, 124), so that the smoke flowing through the filter element from one end part of the inner member to the other end part passes through the outer cavity and each of the inner cavities and flows through the filter material at least four times. 8. Filter element according to one or more of the preceding claims, characterized in that parts of the outer surface of the long sides of the inner cavity longitudinally extending circumferentially at a distance 409812/0877 defined grooves (132, Fig. 7) separated by longitudinally extending ribs (13A) are the outer surfaces of at least a portion of their length with the inner surface of the outer member are engaged. 9. Filter element according to one or more of the preceding Claims, characterized in that the parts of the inner member are at each end of the inner cavity each in the form of a non-crimped plug made of filter material cry (Fig. 5). 10. Filter element according to one or more of the claims 1 to 8, characterized in that the part located at the end of the hollow space which is sent to the inner part (110) and at least a portion of the side walls (116) of the inner cavity are crimped to parts of the outer surfaces spaced from the inner surfaces of the outer member, with longitudinally extending, circumferentially spaced portions (120) of these latter outer surfaces with the inner surface of the outer member come into contact and a plurality of individual elongated outer cavities (128) arises in between (Fig. 4). 11. Cigarette consisting of a tobacco rod and one A filter which abuts one end of the tobacco rod against one another, characterized in that the filter is a filter element according to one or more of the preceding claims. 12. Method of manufacturing a smoke filter element consisting of a connectable filter material including 409 8 12/0877 borrowed a multitude of fibrous limbs in which the Filter material passed in and through an elongated binding zone and there with a binding agent to bind the fibrous members of the filter material brought into contact with one another at the spaced contact points is, so that an elongated, smoke-permeable strand is formed, the binding zone one generally in the axial direction has extending mandrel which defines an annular space through which the filter material must pass, and in which the strand is wrapped with a wrapping paper such that portions of the inner surface of the wrapping material with continuous parts of the. Outer surface of at least part of the strand in contact come, so that sealed areas are formed which prevent the passage of smoke substantially, and in the further, the wrapped strand is severed at selected points to form filter elements, which at least have one of the sealed areas, characterized in that the mandrel (44) is timed with the passage of the filter material (52) through the binding zone (26) between a first position, the at least as far as the path of the filter material is forward than the point (40) at which the filter material with the Binder comes into contact and thereby creates a smoke-permeable ring wall made of bonded fiber links, when the filter material passes this point, and a second position is moved back and forth that so far behind this point in the path of the filter material lies that part of the filter material is completely transverse extends over the binding zone before this point is reached, so that a smoke-permeable plug is bound to it Fiber links are created when the filter material passes this point, the ring wall and the stopper in one piece are with each other and the strand with intermittent inner 409812/0877 λ * Cavities are provided, which are fully closed, closed and from the ring wall and the plug in front and behind are surrounded. 13. The method according to claim 12, characterized in that aokenn ^ eiebnet, that a lot of absorbent, smoke-indicated ad ^ ra Material (78) by de: a thorn during lluckvmri.sbo of the mandrel is fed to at least partially selected Innon cavities with this material in the formation to fill the internal cavities. 14. Statute of limitations according to claim 13, characterized in that that the smoke modifying material contains activated carbon. 15. The method according to one or more of claims 12 to 14, characterized in that selected portions ^r dec strand prior to wrapping of the strand to form Außenhohlräurien between the outer upper hexes of the strand and the inner surface of Unr.- be icklungsrnaterials crimped. 16. Apparatus for the production of smoke filters with a Device for the formation of an elongated binding zone, devices for the continuous supply of filter material of a plurality of fibrous members in and through the binding zone, means for feeding a binding agent into the binding zone and in contact with the filter material at a point between the path of travel of the filter material the binding zone for binding the fibrous links of the filter material to one another at spaced Korrtaktpunktnn and to form an elongated smoke-permeable Rod; with an elongated thorn, whose front end extends in the axial direction within which the binding 09812/0877 zone-defining submissions, κο that a ring area arises through which the filter material must pass, with devices roughly wrapping the rod with a Uiuvri.ck3ungsrcater.ial, so that the surface of the wrapping material continuously *? η Set up the outer surface of at least part of the rod facing each other and create sealed areas that essentially allow the smoke to pass through.;:! prevent, and with means for traversing the wrapped rod fm selected locations for the formation of filter elements, each of which at least one c'er sealed surface). has, characterized by devices (4-3) for the back and forth movement of the »thorns (44) within the binding zone in temporal / -bötimination of the passage of the Filtormoteri & ls zvri.schen a first position in which the front end part extends at least forward in the path of the doβ Filtem & terials up to a point where the filterruate ^ ial comes into contact with the binding agent, so that a smoke-permeable "^; , ^ e ringv.'and from bound FaoerrlieAsrn arises, v / emi the filter material passes this) point, and a second position in which the front part of the wheel extends so far backwards with respect to these points in the path of the filter material that a part of the filter material 3 extends completely across the binder-one extends "before it reaches this point, whereby a smoke-permeable stopper of bonded fiber links is created when passing this point through the filter material and the ring wall and stopper are integral with one another which are, wherein the rod is provided with intermittent internal cavities which are completely closed and surrounded by the annular wall and the plug forwards and backwards. 17. Apparatus according to claim 16, in which the means defining the binding zone have a cylindrical portion and 409812/087 7 BATH ORIGINAL a confronting conical inlet part backwards have from the cylindrical portion in the path of the filter material, characterized in that the front end portion of the mandrel in the first position at least as far forward in the cylindrical portion (28) of the bonding zone ranges, is to be the point cn which the Binder is supplied to the binding zone, and that the front end part of the dome comes to lie in the second position within the conical part (30) of the binding zone. 18. Apparatus according to claim 16 or 17, characterized in that the mandrel is hollow and means (74) are provided through the smoke-modifying material (78) through the mandrel and out of the front dome The end of the same is introduced into the cavities formed in the rod during the return stroke of the mandrel. 4 0 9 8 1 2/0877 Blank page