MX2012012474A

MX2012012474A - Filter additive.

Info

Publication number: MX2012012474A
Application number: MX2012012474A
Authority: MX
Inventors: John SAMPSON; David Rushforth
Original assignee: British American Tobacco Co
Priority date: 2010-05-12
Filing date: 2011-05-11
Publication date: 2013-02-27
Also published as: EP2568833A1; JP2013526272A; NZ603222A; AU2011251791B2; CN102883629B; WO2011141735A1; CN102883629A; RU2565566C2; CL2012003121A1; AR084386A1; BR112012028950A2; CA2798042A1; CA2798042C; EP2568833B1; UA106913C2; KR20130028937A; US20130137561A1; BR112012028950B1; ZA201208308B; JP5872547B2

Abstract

The present invention relates to a method of producing a filter element for inclusion in a smoking article, the method comprising applying an additive to filter material, the additive being solid at room temperature and the method involving heating the additive so that it melts.

Description

ADDITIVE FOR FILTER DESCRIPTION The invention relates to methods for making filter elements and filters for smoking articles where the filter elements and the filters comprise an additive material. In particular, the invention relates to methods for incorporating an additive that is solid at room temperature into the filter material, wherein the method comprises the step of melting the additive material.

A wide variety of materials are used as filter materials for tobacco smoke. The most commonly used filter material is a bundle of cellulose acetate fibers. However, even when cellulose acetate has an excellent ability to filter tobacco smoke it has the disadvantage that it degrades more slowly than other materials and can therefore be disadvantageous from an environmental point of view.

Filter materials that are made from nonwoven laminated material and paper are known. Suitable laminated materials include polyvinyl alcohol, reconstituted tobacco, starch and polylactic acid. These materials degrade much more easily than the cellulose acetate fiber bundle, however, they have their disadvantages. In particular, in order to achieve the desired structural rigidity when constructing a filter element from non-woven laminated materials and paper, the filter material is packaged in a substantially dense manner and this means that these filter elements have fairly good properties. different from those made with cellulose acetate. They exhibit great resistance to flow of smoke which results in a drop in pressure that is higher than that of a conventional cellulose acetate (CA) filter requiring the user to draw more strongly on the smoking article. Perhaps more significantly it was found that the smoke sucked through such a filter material has different taste characteristics when compared to the smoke sucked through the conventional cellulose acetate filter material. Moreover, it has been shown that as a filter material, the filter elements comprising nonwoven laminated materials or paper exhibit a significantly lower selective removal of the semi-volatile compounds than the conventional filter materials of a cellulose acetate fiber bundle. .

It is known to use additives such as triacetin (glyceryl triacetate), TEC (triethyl citrate) and PEG 400 (low molecular weight polyethylene glycol) in cellulose acetate filters. These additives function as plasticizers and are substantially used in the cellulose acetate filters in order to give the filter rods sufficient hardness for the manufacture and use of the cigarettes. Some plasticizers have the additional advantage of providing the bundle with cellulose acetate fibers with an improved capacity in order to selectively remove the semi-volatile compounds such as phenol, o-cresol, p-cresol and m-cresol from tobacco smoke.

These plasticizers are in liquid form at room temperature and are sprayed onto the cellulose acetate fiber bundle. The plasticizer coats the individual fibers within the bundle and eventually unites or coalesces adjacent fibers at their contact points thereby increasing the hardness or stiffness of the filter material in order to give the filter core structural strength desired. However, the mode of action of the plasticizers means that there is an upper limit to the amount that can be incorporated into the cellulose acetate fiber bundle filter material. When more than about 7% plasticizer is included by weight of the filter, the plasticizer begins to have a detrimental effect on the cellulose acetate fiber bundle because holes are formed which compromise its filtering properties.

While the inclusion of plasticizers such as triacetin, TEC or PEG 400 in AC filters is relatively common, its inclusion in paper filter or non-woven laminate materials is less attractive. First, the plasticizers that are used in the AC filters to bond the fibers and the plasticizer clearly do not have this advaeous effect when added to a non-woven laminate or paper (in which the fibers are already bonded within the laminated structure). Secondly, these commonly used plasticizers are liquids and their application to nonwoven and paper laminate filter materials is limited as a result of which they cause these materials to become wet and lose their structural integrity. Paper, the most commonly used laminate filter material, can begin to disintegrate when wet and therefore will have reduced acceptability by the user. In addition, many laminates, including polyvinyl alcohol and polylactic acid, are soluble and therefore the addition of aqueous additives can result in a partial dissolution of the material.

Therefore, an object of the invention is to provide a method of constructing a filter element that is more easily degradable than filter elements comprising a conventional cellulose acetate fiber bundle as the filter material. Preferably, the method will also result in a filter element that exhibits an improved ability to selectively remove the semi-volatile compounds and that provides a smoke having similar taste characteristics to that provided by conventional cellulose acetate filters.

SYNTHESIS OF THE INVENTION According to a first aspect of the present invention, a method for making the filter element of a smoking article is provided. The method comprises the steps of: i) applying an additive that is solid at room temperature to the filter material, ii) heating the additive so as to melt it, and iii) forming the filter material and the additive in a filter element. The steps of the method can be carried out in any order although in some embodiments step i) is preferably carried out before step ¡i).

According to a second aspect of the present invention, a filter element for a smoking article is provided. The filter element comprises a filter material and an additive which is solid at room temperature where the filter element is obtained or obtainable by the method according to the first aspect of the present invention.

According to a third aspect of the present invention, a filter for a smoking article comprising a filter element according to the second aspect is provided.

According to a fourth aspect of the present invention, there is provided a smoking article comprising a filter element according to the second aspect and / or a filter according to the third aspect that is attached to a rod of filling material to smoke. The stuffing material for smoking may comprise tobacco and the article for smoking may be a cigarette.

As used herein, the term "smoking article" includes smoking products such as cigarettes, cigars and cigarillos whether they are based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes and also products that heat up but do not burn.

DETAILED DESCRIPTION The present invention relates to a method of producing a filter element for inclusion in a smoking article, wherein the method comprises the step of applying an additive to the filter material, where the additive is solid at room temperature and the method involves the heating of the additive so that it melts.

In one embodiment of the invention, the additive is applied to the filter material in solid form, for example, in the form of a powder prior to shaping the filter rod. The shaped filter rod can then be heated to melt the additive while remaining in contact with the filter material. Subsequently, when the additive material cools and solidifies again, it provides the filter material and filter element formed with one or more of: stability and rigidity, improved smoke flavor characteristics and selective elimination of the semi compounds -Volitages improved.

In an alternative embodiment of the invention, the additive is melted and applied to the filter material in molten or liquid form prior to shaping the filter rod. Subsequently, when the additive material cools and solidifies again, it provides the filter material and filter element formed with one or more of: stability and rigidity, improved smoke flavor characteristics and selective elimination of the semi compounds -Volitages improved.

The methods according to the present invention can be used to add an additive to any type of filter material including a fibrous filter material or bundles of fibers, such as the cellulose acetate fiber bundle which is currently widely used in the filters of articles for smoking. However, the method is considered to be particularly effective when used to add an additive to alternative filter materials, such as those that are constructed from a laminated material, for example, nonwoven laminates or paper.

The paper filter material usually comprises shirred, pleated, crimped, creped or even shredded paper. Paper filter materials tend to have a low air permeability, exhibit a basic pH and can be easily grouped or shaped to form the filter element. A preferred filter material for the filter elements of the present invention is a shirred or pleated paper. Examples of suitable papers are the Puracel ™ and Myria ™ papers (Filtrona PLC, United Kingdom).

Other non-woven laminate materials can also be used as filter materials. Nonwoven materials are broadly defined as laminated or network structures that are bonded by fibers or filaments entangled mechanically, thermally or chemically or by the combination of two or more of these modes. They tend to be porous and flat sheets that are produced directly from separate fibers. The materials are not made by weaving or knitting and do not require the conversion of the fibers into yarn. The nonwoven laminates used in the present invention are preferably ones that are readily biodegradable. Examples of materials include polyvinyl alcohol (PVOH), polylactic acid or polylactide (PLA), poly (e-caprolactone) (PCL), poly (1-4 butanediol succinate) (PBS) and poly (butylene adipate co-terephthalate) (PBAT). Other suitable filter materials include starch fibers and calcium alginate.

Non-woven laminated materials and paper are more readily biodegradable than the cellulose acetate fiber bundle. However, they presently present disadvantages when used as filter materials. In order to achieve the desired structural rigidity when constructing a filter element from nonwoven laminated materials and paper, the filter material must be packaged very densely and this means that these filter elements have quite different properties than those which They are made with cellulose acetate. They exhibit a high resistance to the flow of smoke which results in a pressure drop that is higher than that of a conventional cellulose acetate filter requiring the user to draw more strongly on the smoking article.

The filter material used in the method of the invention may comprise paper, polyvinyl alcohol, reconstituted tobacco, starch or polylactic acid. Preferably the laminated filter material is paper.

Preferably the nonwoven laminates have a thickness greater than about 0.05 mm, preferably between about 0.06 mm and about 0.08 mm. The paper filter materials can comprise paper having a grammage between about 15 g / m2 and about 40 g / m2, preferably between about 20 g / m2 and about 35 g / m2.

The laminate material used in the method of the invention may also, or alternatively, comprise polyvinyl alcohol (PVOH). PVOH is unique because it is the only biodegradable, it is a polymer with carbon-carbon skeleton that can be completely biodegraded into small molecules, for example, carbon dioxide and water.

The method can comprise the use of the laminated material of polylactic acid. The lactate from which the PLA is produced can be obtained from the fermentation of agricultural by-products.

However, as a consequence of the hygroscopicity of PVOH and PLA, prior art attempts to process such materials resulted in filter rods that were very smooth to be handled efficiently in high-speed cigarette manufacturing machines. In addition, cigarette filter elements that conform to PVOH and PLA have not been able to provide a sufficiently stable porous matrix so as to allow adequate suction characteristics and avoid collapse when used. By using the method of the present invention to apply an additive, the qualities of these laminated materials can be modified so that they are suitable for use in the filter elements.

In contrast to the use of additives that are liquid at room temperature (such as the plasticizers that are often used in conventional cellulose acetate filters, including low molecular weight PEG, triacetin and TEC), an additive that is solid at temperature The environment can provide firmness and rigidity without damaging the filter material and without wetting it.

Indeed, rather than weakening a nonwoven or paper laminate filter material, the method of the present invention uses a solid additive that melts but re-solidifies at room temperature and bonds portions of the filter material. In the case of laminated filter materials, the addition of a solid additive by a method according to the present invention may make it possible to use a smaller amount of filter material in the filter element. This provides more flexibility when forming the filter element in relation to the amount of filter material required to achieve the desired hardness and stiffness. This in turn allows the manufacturer to adjust the pressure drop of the filter element. This allows a filter element according to the present invention to be designed having properties closely resembling that of conventional AC filter elements.

Therefore, the addition of a solid additive to the filter material by the methods according to the present invention can eliminate the defects that are currently associated with the use of the laminated filter materials by improving the rigidity of the filter, improving the taste of the filter. smoke and increasing the selective elimination of the semi-volatile compounds. In addition, the combination of the filter material and the solid additive can provide greatly improved disintegration, dispersion and / or biodegradability of the filter element.

The methods of the invention allow the properties of the nonwoven and paper filter materials to be adjusted so that the performance of the filter element can closely resemble that of a cellulose acetate filter element. These additives also give the use of laminated filter material a much greater flexibility in extending the range of its applicability while retaining the beneficial properties of biodegradation.

In one embodiment of the invention, the additive comprises a high molecular weight polyethylene glycol which is solid at room temperature. Suitable PEGs include PEG 600 and higher and preferably PEG 1000 and higher.

High molecular weight polyethylene glycol has the additional advantage of providing selective removal of semi-volatile compounds. This selective removal of semi-volatile compounds that provides the addition of the PEG to the filter element is proportional to the amount of PEG included. The methods of the present invention that involve the use of a PEG that is solid at room temperature (in contrast to the PEG that was previously used in the filters) provide a flexibility that allows the addition of larger amounts of PEG than is possible. if a liquid PEG is used. This means that the ability of the filter element to selectively remove the semi-volatile compounds can be easily adjusted to a desirable level. This is in contrast to the situation where a low molecular weight PEG is added to the cellulose acetate filters as a plasticizer. It is generally disclosed that cellulose acetate filters include less than 10% plasticizer because the inclusion of higher plasticizer levels than these has a detrimental effect on the cellulose acetate fiber bundle as a consequence of the holes that are formed . Accordingly, the amount of plasticizer available to provide selective removal of the semi-volatile compounds in the cellulose acetate filters is limited.

According to the method of the invention, the PEG can be included in the filter material of the filter element in an amount of up to about 30%, preferably up to about 20% and more preferably between about 5-10% in weight of the filter element.

Since PEG is soluble in water, its inclusion in filter elements should not adversely affect the biodegradation of the product. Surprisingly, in fact it was found that adding PEG to a filter element comprising a nonwoven laminate or paper as the filter material actually improves biodegradation.

A research was carried out to evaluate the effect of the use of a paper filter material and some additives in biodegradability. The degradation of cigarette butts under environmental conditions was evaluated. The samples used included a filter with Puracel ™ (7mg) without additive and a filter with Puracel ™ with 7% PEG 400. The results showed that the inclusion of PEG as an additive significantly increases the rate of biodegradation of cigarette butts on a surface of grass. It is speculated that this is due to the presence of microorganisms, insects and the like that are feed with cigarette butts and the presence of PEG additive makes some butts more attractive. A similar effect is expected if a high molecular weight PEG is used as an additive.

Other additives that may be used in the methods of the present invention include methoxy polyethylene glycols (MPEG) of high molecular weight, such as MPEG 750, 1000, 2000, 3000 and 5000 and waxes which are solid at room temperature, which include beeswax, carnauba wax, shellac wax, castor wax, paraffin wax and various synthetic waxes.

If desired, the method may further comprise incorporating into the laminated filter material more additives, such as tobacco extracts, glycerin, menthol, carbon fibers, carbon particles and the like.

A further advantage of the method of the invention is that the filter elements to which the additive is applied by using the claimed method are more stable for the subsequent addition of additives, including liquid additives. Other additives, including liquid additives, which would otherwise be difficult to apply to the laminate without wetting it, can be added to the filter rod in order to adjust the filter properties as required or provide additional qualities for the filter element , such as flavorings to improve the flavor.

The methods according to the present invention encompass different ways to apply the additive in the filter material.

In one embodiment, the method involves applying the additive to the filter material in liquid form. In order to achieve this, the additive must be heated and sprayed or otherwise applied to the filter material before the filter material conforms to the filter rod or core of the filter element.

This embodiment is attractive because it requires a relatively small modification of the conventional filter making machines. The only real change is the provision of a heating medium of the additive so that it is in a molten state and can be applied in that form to the filter material. The application of heat is relatively easy to control and monitor. In addition, the application of heat is mainly only for the additive and then it is not necessary for the other components of the filter element to be exposed to localized heat.

This method is applicable both to fibrous bundle filter materials, as well as to non-woven laminates and paper. Although such laminated materials are supplied under a certain stress, the application of the liquid additive does not weaken the laminate structure sufficiently to cause a problem.

In an alternative embodiment, the method involves applying the additive to the filter material in solid form, for example, in the form of a powder, before the filter material is conformed to the filter rod or the core of the element of filter. Once the filter rod is formed, it is heated to melt the additive. The additive melts and subsequently solidifies again, joining the filter material without getting wet.

This method allows the additive to be applied in a controlled and uniform manner to the filter material and with minimal losses of additive material. It also avoids any kind of potential drawback associated with the application of a liquid to the filter material. For example, in the case of Laminated filter materials, this embodiment avoids the potential weakening of the laminated structure by means of the application of a liquid.

When the solid additive is applied to a laminated material, such as the non-woven laminate materials and papers that are noted herein, it is necessary to take a series of steps to ensure that the solid additive remains in contact with the laminated filter material. while the laminate is transformed into a filter rod. This may require the application of some adhesive or a special orientation of the laminate.

The filter elements comprise laminated materials that are substantially made using a process comprising the steps of corrugating the laminate and then concentrating the laminate to form a cylindrical filter rod. The additive can be added before or during the rebar process or it can be added to the laminate after being corrugated. The additive can still be added to the corrugated material as it is concentrated to form the filter rod with the effect that it is immediately contained within the rod and does not need to be adhered.

The additive can be adhered to the filter material using any suitable adhesive, for example, using liquid starch adhesives or EVA and PVA adhesives.

The solid additive can be applied to the filter material laminated in powder form or in larger pieces, such as in the form of flakes or granules.

The additive can be applied to the filter material by any appropriate method that is known to the skilled person. For example, a powder additive may be sprayed onto the filter material or may be applied by an applicator that may or may not be in direct physical contact with the filter material. The additive can be applied to the filter material loosely, for example, by being sprayed or sprinkled on the material or it can be applied using a certain force, such as by pressing or covering the filter material.

In a particular embodiment, the filter material is formed with the solid additive embedded therein or on it. The application of the additive, which is solid at room temperature, to the filter material in this way can simplify the methods of the present invention. Once the filter material has been formed on the filter rod, the rod can be heated to melt the additive and then allowed to re-solidify.

Adding various materials in or on laminated materials, such as non-woven laminates and paper, is known. For example, the additive may be applied to the laminate during its manufacture or as part of a step of a post-fabrication process. In this way, the additive can be incorporated within the sheet or as a layer on one or both sides of the laminate. The additive may be present uniformly within or on the surface of the sheet or may be present in discrete areas, such as in the form of patches or strips in the laminate.

The fibrous filter material can also be prepared with particles of solid additive material that is dispersed through the fibers. It may be necessary for such particles to adhere to the fibers. Alternatively, they may be trapped between the adjacent fibers if the fibrous material is sufficiently dense.

When the additive is applied to the filter material in liquid form, the heating step of the method of the invention involves the application of enough heat to the additive to ensure that the additive melts to the point where it has an appropriate viscosity for the chosen mode of application. The molten or liquid additive can be sprayed or printed or the filter material can be immersed in the liquid additive.

According to one embodiment, a system for applying the molten or liquid additive to the filter material comprises a heating chamber in which the additive is kept in liquid form, a pump and a hose with one or more nozzles are configured to spray droplets. on the filter material before the shaping of the filter.

A number of application systems are known which are suitable for applying the molten or liquid additive to the filter material. These systems are available, for example, from SPI Developments, C. B. Kaymich & Co. Ltd or Kohl Maschinenbau GmbH.

When the additive melts after the filter material is formed into a rod or a core, sufficient heat needs to be applied to ensure that all of the additive that is dispersed along the rod is molten.

The application of heat to the shaped filter rod should be done with care as it can have a detrimental effect on the other components of the filter rod, including the filter material and any wrapper (which is likely to be paper and can scorch or burn due to exposure to high temperatures).

Obviously, the temperature at which the filter rod must be heated and the duration of the heating depends on the melting point of the additive. A preferred additive, PEG 1000, has a melting point of about 37 ° C and therefore in this case the filter rod is heated to a temperature exceeding 37 ° C. The filter rod can be heated to a temperature exceeding 40 ° C, preferably exceeding 45 ° C and more preferably exceeding 50 ° C. In addition, it is necessary to apply the heat for a sufficient period of time to ensure that the entire rod is heated and not only the external areas.

The heat can be applied using any appropriate means. For example, the filter rod or the filter element can be placed very close to a heating element. Alternatively or additionally, the filter rod or the filter element can be heated by means of a stream of hot gas, such as hot air or steam or by means of the application of radiation, such as microwave radiation.

The heat can be applied to the filter rod as soon as it is formed. In other words, the heating of the filter rod can occur at some stage between the formation of the filter rod in the lining and the cut, when the filter rod is separated into sections. The heating of the rod will be substantially during a very short period, such as less than 1 second, as a consequence of the linear movement of the rod through the machine. Clearly, since the filter rods are currently formed without a heating process, then a simultaneous shaping and heating of the filter rod may require expensive modifications of the current apparatus.

Preferably for this reason the filter rod is heated at a later stage and this can be achieved by using a heater that is essentially separate from the apparatus that is involved in shaping the filter rod. The heating is preferably carried out in a separate conditioning step, where the length of the filter rod is maintained at an elevated temperature for a long period of time in order to ensure that all the additive melts and binds to the material of the filter. filter.

The method of the invention may further comprise wrapping the filter rod in an appropriate wrapper, such as a filter paper. In this case, the heat can be applied before wrapping the filter rod. Alternatively, the filter rod can be wrapped and then heated.

According to some embodiments, the reinforced filter is heated to melt the additive although this approach may be complicated by the insulating properties of the filter material. further, the filter manufacturing speed means that the time available for heating the filter is limited. That said, heating the armed filter can be accomplished in several ways. For example, the filter rod may be exposed to heat by conductance, such as in a drum heated in the presence of hot air. Alternatively, filter rod trays (such as 4000 filters per tray) can pass through a heated tunnel or similar arrangement in the presence of hot air. Alternatively, the filter trays may be heated by the application of radiation, such as microwave radiation.

The methods of the present invention may further comprise a step of incorporating particulate material into the filter element. Suitable particulate material includes sorbents (for example, which are selected from activated carbon, charcoal, silica gel, sepiolite, alumina, ion exchange material, etc.), pH modifiers ( example, alkaline materials such as Na 2 CO 3, acidic materials), flavorings, other solid additives and mixtures thereof.

Advantageously, the particulate material can be selected from a group of materials with relatively high surface areas with the ability to adsorb the smoke constituents without a high degree of specificity. Substantially suitable adsorbents can be selected from the group consisting of carbon, activated carbon, activated charcoal, activated coconut charcoal, carbon or activated charcoal from carbon, zeolite, silica gel, sea foam, aluminum oxide ( activated or not), carbonaceous resin or combinations thereof.

One type of particulate material that can be used in the method of the invention is carbon, for example, activated carbon or charcoal or other carbonaceous absorbent material. The preferred type of activated carbon is activated coconut charcoal.

The particulate material may be incorporated in the filter element such that it is intermixed throughout the filter element or intermixed in some (but not all) parts of the filter element. The particulate material can be intermixed over the entire longitudinal length of the core. Alternatively, the particulate material may be intermixed from one end of the core to a section that is near the other end. Alternatively, the particulate material may be present in discrete areas that do not need to extend from - or are present at - any end of the core. Different areas may have different charges of particulate material and / or different types of particulate material.

The methods of the present invention may further comprise the step of wrapping the filter element in an appropriate envelope.

The envelope of the filter element is preferably a paper wrapper and more preferably conventional filter paper, such as filter paper having a grammage of between about 20 g / m2 and about 35 g / m2, preferably about 27 g / m2 . The filter paper can be porous or non-porous.

The method may comprise the use of a wrap that includes a particulate material adhered to one or more portions of its surface. Preferably, the particulate material adheres to two or more portions of the envelope, wherein the portions are circumferentially spaced apart from each other with at least one of the portions extending over the entire longitudinal length of the envelope.

The filter element of the smoking article made according to the method of the present invention can be incorporated into the filter of a smoking article.

The filter of the smoking article may comprise a single filter element of the method of the invention. Alternatively, the filter of the smoking article may include two or more filter elements produced according to the method of the invention. In other words, the filter element can be part of a composite (or multi-component) filter. Properly, the filter elements of the composite filter are arranged longitudinally with each other with the end of each filter element abutting the next. The composite filter can have 2, 3, 4 or more discrete or discrete sections.

In one embodiment, the filter is a triple filter with three sections. In another embodiment, the filter is a dual filter with two sections.

The filter sections of the composite filter may be identical or alternatively one or more of the sections may have a composition that is different from that of the other section or sections. For example, in some embodiments one or more of the sections may optionally comprise: (i) cellulose acetate filter material, (ii) a biodegradable filter material, such as creped, crimped or shirred paper, (iii) one or more additives, such as adsorbent or flavoring materials, which may be encapsulated and / or (iv) a cavity, which may comprise granulated material, such as adsorbent material.

The filter element of the smoking article made according to the method of the present invention can be incorporated into a smoking article. The filter element may be in the form of a filter of a smoking article as described above.

The filter element and / or the filter comprising the filter element can be attached to a rod of filling material for smoking with a wrapper (ie, for example, a wrapped tobacco cylinder) by means of a nozzle wrap conventional in order to conform the article of smoking, which can be a cigarette.

Conveniently, the smoking filler material can be tobacco material or a tobacco substitute material. Preferably, the smoking material is tobacco material. Suitably, the tobacco material comprises one or more of tobacco stem, sheet and powder. It is preferred that the tobacco material comprises one or more of the following types: Virginia or smoke-cured tobacco, Burley tobacco, oriental tobacco or reconstituted tobacco. By preference, the smoking material comprises a mixture of tobacco material.

The smoking filler material may also comprise one or more of the following: flammability modifier, ash improver, inorganic filler material, organic filler, aerosol generating medium, binder, flavoring and / or coloring agents.

The nozzle wrap can be a vented or unventilated wrap.

Various modifications and variations of the methods and system described in the present invention will be apparent to those skilled in the art without departing from the scope of the present invention. Although the present invention has been described in connection with specific preferred embodiments, it is to be understood that the invention, as claimed, should not be unduly limited to such specific embodiments. Of course, various modifications of the modes described to carry out the invention, which are apparent to those skilled in the art, are intended to be within the scope of the following claims.

Claims

1. A method for producing the filter element of a smoking article comprising laminated filter material and an additive, characterized in that the method comprises the steps of: i) applying an additive that is solid at room temperature to the laminated filter material, ii) heating the additive to melt it, and iii) forming the laminated filter material and the additive in a filter element, where the steps of the method can be carried out in any order.

2. A method according to claim 1, characterized in that the additive material is applied to the laminated filter material before the formation of the filter element and subsequent heating of the additive.

3. A method according to claim 1, characterized in that the additive is heated and applied to the laminated filter material as a liquid prior to the shaping of the filter element.

4. A method according to any one of the preceding claims, characterized in that the additive comprises a high molecular weight polyethylene glycol which is solid at room temperature.

5. A method according to claim 4, characterized in that the polyethylene glycol is PEG 1000.

6. A method according to any one of the preceding claims, characterized in that the additive is included in the filter element in an amount of up to about 50% by weight of the filter element.

7. A method according to any one of the preceding claims, characterized in that the laminated filter material is nonwoven laminate or paper.

8. A method according to any one of the preceding claims, characterized in that the filter element further comprises at least one adsorbent material.

9. A filter element for a smoking article, comprising laminated filter material and an additive which is solid at room temperature, wherein the filter element is obtained or obtainable by a method according to any one of the preceding claims.

10. A filter for a smoking article comprising a filter element according to claim 9.

11. A smoking article comprising a filter element according to claim 9 and / or a filter according to claim 10 and a rod of smoking filler material.

12. An article for smoking according to claim 1, characterized in that the article is a cigarette.