Field of invention The present invention relates to a filter component for an aerosol-generating article such as cigarettes, heat-not-burn articles, and vaping products in general. More specifically, it relates to a filter component that provides a more pleasant vaping experience.

Background Use of e-cigarettes or heat-not-burn vaping devices is becoming popular these days. These products deliver a flavored or non-flavored inhalable aerosol to a user. Typically, an aerosol-generating source, such as a liquid or a solid heatable substrate containing an aerosol generating substance is heated or vaporized to generate aerosol without combustion. Similar to conventional cigarettes, these devices, and in particular heat-not- burn articles, may include one or more filter elements in the air channel to filter certain compounds and particles in the aerosol before it is delivered it to the user for inhalation.

Meanwhile, the use of conventional cigarettes remains widespread. Therefore, there is a constant need for improving filtration of mainstream smoke generated during use of such articles as well as to provide consumers with different taste experiences. Currently, known existing filters for such vaping products mostly mimic filters used in conventional cigarettes. Regular users have however reported a need for cooler aerosol upon inhalation as they often feel the aerosol and/or mouthpiece of the articles through which they are inhaling to be too hot in use, and certainly hotter than the mouthpiece of a conventional cigarette. This is mostly due to the shorter distance travelled by the aerosol in a vaping article from the heating point of the aerosol-generating material where the aerosol is generated to the mouthpiece compared to conventional cigarettes for example, at least for the major part of the consumption thereof. l There have been attempts to reduce heat of aerosols through increased filter ventilation or alternative filter material compositions, for example. However, these solutions tend to undesirably alter the taste of the aerosol. An aim of the invention is to provide a new filter for aerosol-generating articles such as smoking articles, e-cigarettes, and heat-not-burn products, and the like, which allows sufficient cooling of the aerosol generated by such articles as well as provide a more enjoyable vaping experience to the users. Summary of the invention

According to an aspect of the invention, there is provided a filter component for an aerosol-generating article comprising a core comprising filtration material wrapped around by a first wrapper, wherein the first wrapper is air impermeable and comprises a plurality of corrugations of sinusoidal waveform extending longitudinally along a sinuous air flow path from and/or to a longitudinal end of the filter component at least.

Advantageously, such filter component inhibits mixing of the aerosol and the outside air thereby enhancing the user experience. Also, the corrugations along a sinuous air flow path create a cooling effect.

Preferably, the filter component further comprises a second wrapper configured to wrap around the first wrapper such that the corrugations define channels between the first wrapper and the second wrapper.

Preferably, the second wrapper comprises perforations in fluid communication with the channels to create an airflow through the channels by drawing on the filter component.

Advantageously, the channels between the first and the second wrapper provide ventilation and cools down the aerosol passing thorough the filter component.

Preferably, the wave length of the sinusoidal waveform is in the range of 1 mm to 3 mm.

Preferably, the amplitude of the sinusoidal waveform is in the range of 0.5 mm to 2 mm.

Preferably, the first wrapper comprises plastic material, and preferably polylactic acid. Advantageously, the wrapper formed of such material is air impermeable and is strong enough to not bend or tear during manufacturing. Also, it is suitable for forming corrugations of desired shape and size.

Preferably, the first wrapper has Modulus of Elasticity in the range of 1.09 to 2.28 GPa. Preferably, the first wrapper has Elongation at Break in the range of 2.5 to 24%.

According to another aspect of the invention, there is provided a filter for an aerosol generating article comprising at least a first filter component having features described above.

Preferably, the filter includes at least one second filter component, different from the first filter component, coaxially arranged longitudinally at an end of the first filter component and maintained therewith with an outer wrapper wrapped around both the first and second filter components.

Advantageously, an extra layer of filtration can be provided using the second filter component and the filter components can be held together with the help of the outer wrapper.

Preferably, the second filter component is at least partially hollow along a longitudinal axis of the second filter component.

Advantageously, this can provide extra cooling effect for the aerosol.

According to another aspect of the invention, there is provided an aerosol-generating article comprising a charge of aerosol-generating substrate and a filter as described above attached at an end thereof such that the first filter component is abutting against said charge of the aerosol-generating substrate.

According to yet another aspect of the invention, there is provided a method of forming a filter component for an aerosol-generating article, the method comprising: forming a plurality of corrugations of sinusoidal waveform extending longitudinally at least partly along a sinuous air flow path on a non-air permeable first wrapper from an end thereof; providing a core of filtration material; and wrapping the first wrapper around the core. Preferably, the corrugations are formed by pressing and heating the inner wrapper between two embossing rollers.

Preferably, a second wrapper is wrapped around the first wrapper such that the corrugations define air channels between the first wrapper and the second wrapper.

Brief description of the drawings

The present invention will now be illustrated by way of example with reference to the accompanying drawings, in which: Fig. 1 shows an aerosol-generating device with a filter component according to one aspect of the invention;

Fig. 2 shows a cross-sectional view of the filter component of Fig. 1 ;

Fig. 3A shows a side view of a first example of the filter component partially wrapped in an outer wrapper; Fig. 3B shows a side view of a second example of the filter component partially wrapped in an outer wrapper;

Figs. 4A and 4B show two different examples of the aerosol-generating device with the filter component;

Fig. 5 shows two examples of wave pattern formed in the filter component; and Fig. 6 shows a production line for manufacturing the aerosol-generating device with the filter component.

Detailed description

Next, various embodiments of the invention will be described in relation to an aerosol- generating article 100 in the form of a heat-not-bum stick as represented in Figures 1 , 4A and 4B in particular. While the foregoing examples are depicted in relation to a heat-not- burn article the present invention shall not be construed as limited to heat-not-burn articles but can also be applied indifferently to cigarettes, cigarillos or the like. Note that the same or similar portions are denoted with the same or similar reference signs in the descriptions of the drawings below. Note that the drawings are schematic and a ratio of each size is different from a real one. Therefore, specific sizes and the like should be judged in consideration of the following descriptions. Needless to say, portions of which relationship and ratios of mutual sizes are different between the mutual drawings are included.

As shown in Fig. 1 , an aerosol-generating article 100 comprises a rod-like structure comprising a mouthpiece section 101 and an aerosol-generating section 102. The mouthpiece section 101 has an air-channel defined between an inner end 102a of the aerosol-generating section 102 and a mouth end 103a. The mouthpiece 101 is preferably formed of two components comprising in the represented example of Fig. 1 of a paper tube filter segment 105, and a mouth end filter component 106. The aerosol generating section 102 comprises an aerosol source 104, which could be formed of any suitable substance comprising a flavor and/or a stimulant such as nicotine, and a non mouth end 103b. Preferably, the aerosol source 104, which may be or at least comprises tobacco, releases an aerosol when heated using a heat source (not shown) without combustion. The paper tube 105 is preferably a hollow component made of paper or paper-like material provided to cool down the aerosol. The filter component 106 comprises a core containing a filtration material such as crimped cellulose acetate fibers, as in conventional cigarette filters, to filter any unwanted compounds in the generated aerosol. The core is wrapped around by a structured inner wrapper comprising zig-zag or sinusoidal wavelike pattern channels extending longitudinally from at least one end of the mouth end filter component 106, and preferably along the entire length of the filter component 106.

It is to be understood that the article 100 may be of any suitable shape and size and may include other components not shown in the figure.

Fig. 2 shows a cross-sectional end view of the filter component 106. As described above, the filter component 106 includes an inner wrapper 201 surrounding the core 202 comprising filtration material such as filaments of cellulose acetate. Preferably, the inner wrapper 201 is made from Polylactic Acid (PLA) plastic, Cellulose Acetate, or other suitable material that has Modulus of Elasticity In the range of 1.09 - 2.28 GPa and Elongation at Break in the range of 2.5 - 24%. Moreover, porosity of the inner wrapper

201 is preferably below 10 CU, thereby making the inner wrapper 201 substantially air impermeable. The inner wrapper 201 is wrapped around by an outer wrapper 203 which is preferably made of air-permeable material. The outer wrapper 203 has non-corrugated surface such that when it is wrapped around the inner wrapper 201 with sinusoidal waveform pattern, air channels 204 are formed between them.

In use, a user draws air at the mouthpiece end 103a while the aerosol generating source 104 is heated. Heat generated aerosol is sucked from the aerosol generating section 102 through an intermediate channel formed by the paper tube 105 and enters into the core

202 as it passes through the filter component 106. The aerosol is filtered by being in contact with the filtration material present in the core 202. In this example, because the outer wrapper 203 is air permeable, cooling air is drawn from outside into the channels 204. Aerosol passing through the core 202 of the inner wrapper 201 is however not mixed with the cooling air as the inner wrapper 201 is air impermeable. The cooling air in the channels 204 however enters the user’s mouth where it is mixed with the aerosol and cools it down. The user is therefore provided with the aerosol at a comfortable temperature for inhalation. Moreover, as the aerosol is not mixed with the outside air due to the presence of the inner wrapper 201 , the intensity of the flavor or the substance in the aerosol is not reduced which further enhances the user experience.

As shown in Fig. 2, the inner wrapper 201 is wrapped around the filtration material filled in the core 202 of the filter component 106. The filtration material could be a tow or nonwoven fabric of cellulose acetate, polypropylene or other fibrous materials for filtering any unwanted compounds in the aerosol. Specifically, the filtration material is used to remove particulate components and gaseous vapor components of substance such as tobacco contained in the aerosol. If the aerosol simply contains a flavor, no filtration may be needed and the core could therefore be hollow.

The outer wrapper 203 is wrapped around the inner wrapper 201 to provide rigidity and as well as comfort to the user. The outer wrapper 203 may be made of paper or air- permeable material which allows the outside air to penetrate inside the channels 204 formed between the inner wrapper 201 and the outer wrapper 203. The outer wrapper 203 may also be perforated to allow proper air intake into the air channels 204. The channels 204 are formed by the virtue of sinusoidal waveform pattern in the inner wrapper 201 and aid in cooling the aerosol passing through the filter component 106. As described above, the air in the channels cannot penetrate through the inner wrapper 201 and therefore the aerosol is not mixed with the outside air in the filter component 106.

It is to be noted that the channels 204 are formed circumferentially at one or both ends of the filter component 106 and longitudinally along sinusoidal corrugations formed at least partially along the length of the filter component 106. The channels 204 formed in this way in the inner wrapper 201 provide enhanced cooling effect as compared to the existing filters.

Fig. 3A shows the filter component 106 according to one aspect of the invention. In this, the sinusoidal waveform pattern in the inner wrapper 201 extends longitudinally through along a sinuous air flow path throughout the inner wrapper from the mouth end 103a to the non-mouth end 103b. As the aerosol travels through the wavy path of the filter component 106, its speed of travel is lowered and the path also creates the pressure drop. This therefore cools down the aerosol before it reaches the mouth end 103a.

Fig. 3B shows the filter component 106 according to another aspect of the invention. In this, the sinusoidal waveform pattern in the inner wrapper 201 extends longitudinally along a sinuous path from the mouth end 103a to a certain point in the inner wrapper 201 but not up to the non-mouth end 103b. In the present example, the waveform pattern extends up to midway into the inner wrapper 201. The rest of the inner wrapper 201 is not embossed and could simply have a plain surface. In use, a mainstream smoke coming from the aerosol generating section 102 attached at the non-mouth end 103b of the filter component 106 will only go through the core 202 of filtration material and not in the channels 204 formed in the inner wrapper 201. Moreover, the air channels 204 will act as a cooling barrier to the hot smoke circulating in the core 202 towards the outside of the filter component 106 where the user’s lips touch the surface of the outer wrapper 203. Furthermore, where ventilation holes are provided in the outer wrapper 203, in fluid communication with the channels 204, fresh air is drawn into the channels 204 towards the mouth end 103a. This air is then drawn into the user’s mouth together with the aerosol passing through the core 202 offering a cooling sensation in the user’s mouth, thereby creating a pleasant vaping experience.

In both examples of Figs. 3A and 3B, preferably, the length of the filter component 106 is about 15 mm, circumference is 21.7 mm, and the number of channels formed is in the range of 5 to 10.

Figs. 4A and 4B show the article 100 with a tube-shaped filter component 401. The tube shaped filter component 401 may be included in the article 100 to provide an additional extension to the filter. The tube-shaped filter component 401 may extend the path of the aerosol in reaching the user’s mouth. This could provide further cooling effect. In the device shown in Fig. 4A, the tube-shaped filter component 401 is provided at the mouth end 103a adjacent the paper tube 105. The filter component 106 with the sinusoidal waveform pattern is sandwiched between the paper tube 105 and the aerosol source 104. In this configuration, the aerosol is first cooled down in the filter component 106 as soon as it escapes the aerosol source 104. The cooled down aerosol then travels through the paper tube 105 and the tube-shaped filter component 401 , where it may get cooled a bit further before reaching the user’s mouth.

In the device shown in Fig. 4B, the tube-shaped filter component 401 is disposed away from the mouth end 103a and is sandwiched between the filter component 106 and the paper tube 105. The filter component 106 is disposed at the mouth end 103a. In this configuration, the aerosol may not be cooled down considerably when passing through the paper tube 105 and the tube-shaped filter component 401. However, on passing through the filter component 106, the aerosol cools down to a comfortable temperature due to the presence of the air channels 204 before reaching the user. Moreover, as the filter component 106 has a layer of the inner wrapper 201 as well the outer wrapper 203, the temperature at the tip of the device 100 would also be lower.

It is to be understood that the tube-shaped filter component 401 , the paper tube 105, and the filter component 106 are preferably wrapped together using a plug wrap (not shown). Moreover, the paper tube 105 and the tube-shaped filter component 401 are optional components and one or both of them may be omitted. Fig. 5 shows examples of waveform pattern formed on the inner wrapper 201 . Pattern 501 is a simple sinusoidal waveform with repeating peaks and troughs. The distance between two adjacent peaks, referred to as wave length, a, is preferably in the region of 1 to 3 mm. The height of each wave, referred to as amplitude, b, is preferably in the region of 0.5 to 2 mm. Pattern 502 is a modified sinusoidal waveform with flattened surfaces. The amplitude, b, of the waveform in pattern 502 is preferably also in the region of 0.5 to 2 mm.

Fig. 6 shows a filter manufacturing process for the device 100. A manufacturing apparatus 600 comprises three main sections, namely, a tow processing unit 601 , a channel forming unit 602, and a rod formation unit 603. The tow processing unit 601 includes components such as guide rollers, pretension rollers, feed roller, air spreaders, etc. which are well-known in the art. The waveform pattern or the channels in the inner wrapper 201 are formed in the channel forming unit 602, which is placed between the tow processing unit 601 and the rod formation unit 603. The inner wrapper 201 is pressed between a pair of embossing rollers 603, which may be heated, to create a pattern on the inner wrapper 201 . The pattern created may be continuous, interrupted or zigzag.

After the inner wrapper 201 is embossed, it is optionally filled with filtration material and wrapped around by the outer wrapper 203 in the rod formation unit 603. In this way, the filter component 106 is produced for use in the device 100. According to the invention described above, it is possible to provide an aerosol generating device including a filter component that provides a pleasant user experience by cooling down the aerosol to a comfortable temperature without mixing it directly with the outside air. Moreover, as the inner wrapper 201 is made of a more rigid material, it is less susceptible to bend or tear during the manufacturing process. Furthermore, forming a desired pattern on such inner wrapper is easier.

It is to be understood that the shape, size, and design of the filter component 106 can be modified according to other components of the device 100. Moreover, the positioning of the filter component in the device 100 can also be adjusted based on the requirements. The choice of material for forming the filter component, the outer wrapper, the paper tube, the filtration material, etc. is also not limited by the examples presented above. Furthermore, additional components may be present in the device. For example, a flavor capsule including a flavor may also be provided in the filter component 106 or in one of the other parts of the device. With this configuration, the user may also be able to crush the flavor capsule, to increase the intensity of flavor contained in it.

Although, the invention is described primarily with respect to heat-not-burn type e- cigarettes, the filter component 106 is also applicable for use in other types of e- cigarettes or conventional cigarettes.

The foregoing description of illustrative embodiments has been presented for purposes of illustration and of description. It is not intended to be exhaustive or limiting with respect to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosed embodiments.