Sustainable filter or filter element

Abstract

A filter (1) for use in an aerosol-generating article, the filter comprising a first section and a second section constituting a longitudinally extending core wherein the first section (3) comprises a first filter material wherein the second section (7) comprises a second filter material having a pressure drop of 0.1 mmWG to 0.5 mmWG per mm of its length, the filter further comprises a wrap (11) enclosing the longitudinally extending core, wherein the first filter material and the second filter material comprise paper and / or other biodegradable material.

Description

[0001] INTRODUCTION

[0002] The present invention provides a sustainable filter or filter element for use with an aerosol generating article such as a tobacco heating product, a heat-not-burn product or a heat tobacco product. BACKGROUND

[0003] Tobacco heating products or heat-not-burn (HNB) products, also known as heat tobacco products or HTP products, are well known. The concept of tobacco heating products is to heat tobacco to a specific temperature, such as 350°C, without burning. This delivers a vapour containing nicotine and it is believed that heating without burning avoids the production of combustion products which are harmful to the consumer.

[0004] Tobacco heating products or HNB or HTP products can include a modified tobacco rod and other mouthpiece elements which are wrapped in a paper plug wrap in order to provide a cigarette-like appearance. In one such product, a reconstituted tobacco rod, a wrapped hollow acetate tube, a wrapped PLA [poly(lactic acid)] rod and a conventional wrapped acetate segment (at the mouth end) are wrapped in white paper. In use, the product is inserted into a device, the tobacco end first. The tobacco rod contains a metal strip which, when inserted into the device, can be heated by induction, so the consumer can then “puff” on the product. The function of the “filter” in these products is very different from that of a cigarette filter; the main functions are to provide the appearance and feel of a cigarette, and to cool the vapour to a temperature acceptable to the consumer. In the product described above, the significant cooling function is performed by the PLA portion, and so this portion can be considered to be a cooling element.

[0005] It is well known to use materials such as PLA for cooling elements. More recently, it is known to use cellulose acetate for cooling elements, as discussed in WO2021 / 074222.

[0006] However, cellulose acetate and PLA are not readily biodegradable. Thus, aerosol generating article elements containing filter elements and cooling elements, such as cellulose acetate, can be present in the environment for many years. As such, and in view of new EU legislation coming into force in 2021 (aimed at reducing the use of single-use plastics such as cellulose acetate filters), there is increasing interest in filters and filter elements which are free of single-use plastics and which are readily biodegradable.

[0007] Accordingly, there is a need for a filter and filter element which provides acceptable vapour cooling and acceptable filtration performance in HTP products, whilst having improved biodegradability over conventional materials such as cellulose acetate. SUMMARY

[0008] According to the present application, there is provided a filter (e.g. a biodegradable filter, e.g. a readily biodegradable filter) for use in an aerosol-generating article (e.g. a filter for a tobacco heating product and / or an HNB / HTP product), the filter comprising a first segment and a second segment constituting a longitudinally extending (e.g. cylindrical) core; wherein the first segment comprises a first filter material; wherein the second segment comprises a second filter material having (e.g. providing) a pressure drop of 0.1 mm WG to 0.5 mm WG per mm of its length (e.g. a pressure drop of 0.15 mm WG to 0.45 mm WG per mm of its length, e.g. a pressure drop of 0.2 mm WG to 0.3 mm WG per mm of its length, e.g. a pressure drop of 0.21 mm WG to 0.29 mm WG per mm of its length, e.g. a pressure drop of 0.22 mm WG to 0.25 mm WG per mm of its length, e.g. a pressure drop of 0.23 mm WG per mm of its length); the filter further comprising a wrapper (e.g. a filter wrapper) enclosing the longitudinally extending core; wherein the first filter material and the second filter material comprise paper and / or other biodegradable material. Preferably, the second filter material has a pressure drop of 0.2 mm WG to 0.3 mm WG per mm of its length, e.g. a pressure drop of 0.21 mm WG to 0.29 mm WG per mm of its length, e.g. a pressure drop of 0.22 mm WG to 0.25 mm WG per mm of its length, e.g. a pressure drop of 0.23 mm WG per mm of its length.

[0009] In some examples of the filter, the first segment is longitudinally separated from the second segment, such that the wrapper defines a cavity between the first segment and the second segment.

[0010] The first segment can be formed from paper (e.g. Puracel FM26, Puracel FM36 and / or Greenbutts) and / or other biodegradable material that is laterally gathered into a rod form and held in place (e.g. by the wrapper, e.g. by a first segment wrapper). It will be appreciated that the first segment can have a wrapper (e.g. a first segment wrapper) that holds the filter material into a shape (e.g. into a core form, e.g. into a rod or core rod form). This wrapper (e.g. first segment wrapper) is separate, for example, from the wrapper (e.g. filter wrapper) that engages around the first segment and the second segment. If there is a wrapper (e.g. a first segment wrapper) for the first segment, it will be appreciated that the wrapper (e.g. filter wrapper) that encloses the first segment and the second segment wraps around the wrapper (e.g. first segment wrapper) of the first segment as well as the first segment itself.

[0011] The second segment can be formed from a paper material (e.g. uncoated paper, coated paper, siliconised paper, e.g. ZNP paper) and / or other biodegradable material which is laterally gathered into a rod form and held in place (e.g. by a wrapper, e.g. a second core wrapper). The second segment can be formed from a paper material (e.g. uncoated paper, coated paper, siliconised paper, e.g. ZNP paper) and / or other biodegradable material which is 20mm to 250mm, e.g. 151mm to 250mm, e.g. 180mm to 220mm, e.g. 200mm in width which is laterally gathered into a rod form and held in place (e.g. by a wrapper, e.g. a second segment wrapper). It will be appreciated that the second segment can have a wrapper (e.g. a second segment wrapper) which holds the filter material into a shape (e.g. into a core form, e.g. into a rod or core rod form). This wrapper (e.g. a second segment wrapper) is separate, for example, from a wrapper (e.g. a filter tip wrapper) which is joined around the first segment and the second segment. If a wrapper (e.g. a second segment wrapper) is present for the second segment, it will be appreciated that the wrapper (e.g. a filter tip wrapper) which is joined around the first segment wraps around the wrapper (e.g. a second segment wrapper) of the second segment as well as the second segment itself.

[0012] The Applicant has surprisingly found that filter tips according to aspects of the present application combine biodegradability ("readily biodegradable") with a thermal profile and / or comparable aerosol chemical delivery to products on the market which use cellulose acetate and PLA. Further, the Applicant has found that filter tips of the present application can be adapted to provide a customizable design to match a desired aerosol chemical delivery profile.

[0013] Preferably, the wrapper (e.g. a filter tip wrapper) defines a longitudinal cavity between the first segment and the second segment within the longitudinally extending core. The Applicant has found that this can allow for mixing of the aerosol with air which can reduce the temperature of the aerosol. The filter tip wrapper can be a paper material (e.g. cigarette paper), preferably a paper material (e.g. cigarette paper) having a basis weight of 20gsm to 160gsm, e.g. 24gsm to 150gsm, e.g. 70gsm to 150gsm, e.g. 70gsm to 140gsm.

[0014] Preferably, the wrapper (e.g. a filter tip wrapper) provides a ventilation means. Preferably, the ventilation means is provided by one or more perforations in the wrapper (e.g. a filter tip wrapper). Preferably, the ventilation means is aligned with the cavity. The Applicant has found that ventilation can allow for external air to enter the cavity which can help to reduce the aerosol temperature.

[0015] Preferably, the second segment has a density of 0.18g / cm3to 0.25g / cm3, e.g. 0.18g / cm3to 0.22g / cm3, e.g. 0.18g / cm3to 0.20g / cm3.3 to 0.28 g / cm 3 for example 0.19 g / cm 3 to 0.26 g / cm 3 for example 0.2 g / cm 3 to 0.25 g / cm 3 for example 0.211 g / cm 3 of paper density.

[0016] The first filter material can comprise paper and / or other biodegradable material which is readily biodegradable. The second filter material can comprise paper and / or other biodegradable material which is readily biodegradable. Preferably, each of the first filter material and the second filter material comprises paper and / or other biodegradable material which is readily biodegradable.

[0017] The term "readily biodegradable" means that the filter material and element is capable of exhibiting a biodegradation rate of at least 90% after 6 months under controlled composting conditions (see ISO 14855-1 Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions - Method by analysis of evolved carbon dioxide).

[0018] Preferably, the paper and / or other biodegradable material (e.g. cellulose acetate free material) used in the filter material of the filter of the application is "readily biodegradable" and has enhanced biodegradability compared to cellulose acetate. Thus, the present application provides an element with enhanced biodegradability, thus being more environmentally friendly and more in line with EU legislation.

[0019] The phrase "readily biodegradable" means that the filter material and filter is capable of rapidly breaking down and fully biodegrading when immersed in water. Preferably, the element has a biodegradation rate of "readily biodegradable" level as measured according to the OECD 301 B "readily biodegradable" method (modified Sturm test) which is well known in the art. The phrase "readily biodegradable" is understood herein to mean a biodegradation rate of "readily biodegradable" level.

[0020] The paper and / or other biodegradable material (e.g. acetate cellulose free filter material) is preferably readily biodegradable. The paper and / or other biodegradable material (e.g. acetate cellulose free filter material) can comprise any paper (in any form) conventionally used in filter tips or filter tip elements. The paper can be, for example, filter paper of different grades, perforated paper, creped paper, air-laid paper or machine glazed paper, etc. The paper and / or other biodegradable material (e.g. acetate cellulose free filter material) can be of natural fibres (e.g. flax, sisal, jute, abaca, cotton, coconut fibres, bamboo fibres, starch (e.g. from corn) or tobacco) or any rolled material. The paper can be woven or non-woven, or in the form of a bonded paper web, or in the form of a longitudinally corrugated and / or fibrillated paper web, for example laterally gathered into and held as a core rod form. The paper and / or other biodegradable material (e.g. acetate cellulose free filter material) can be in the form of a bonded paper web comprising a first paper and / or other biodegradable material (e.g. acetate cellulose free filter material) and a second paper and / or other biodegradable material (e.g. acetate cellulose free filter material). The paper and / or other biodegradable material (e.g. acetate cellulose free filter material) can be in the form of a blend of different paper materials and / or other biodegradable materials (e.g. acetate cellulose free filter material). The paper filter material can have the same or similar structure as those sold under the trade marks or (essentra plc). The paper can be coated with a hydrophobic coating or hydrophobic material.

[0021] The hydrophobic coating / material, if present, can be any suitable hydrophobic material. For example, the hydrophobic coating / material can be a polymer or a blend of polymers. Preferably, the hydrophobic coating / material is starch, such as modified starch, for example oxidised starch (E1404). Starch, such as modified starch, is preferred as it is inert and provides a non-plastic hydrophobic coating. The hydrophobic coating / material can be present in an amount of 0.01 to 50 wt% of the hydrophobic coating / material, for example 0.01 to 20 w / w%, for example 0.1 to 20 w / w%, for example 5 to 20 w / w%, for example 10 to 20 w / w%, for example 0.1 to 10 w / w%, for example 0.1 to 5 w / w%, for example 0.5 to 2.5 w / w% relative to the weight of the element (w / w).

[0022] The coated paper according to the present application is manufactured by methods known in the art. The hydrophobic coating can be applied to the paper via any of the standard coating methods known in the art.

[0023] The first filter material can comprise paper and / or other biodegradable material that is readily biodegradable. The first filter material can comprise paper and / or other biodegradable material as described in the paragraphs above. In some examples, the first filter material comprises Puracel FM26, Puracel FM36 and / or Greenbutts.

[0024] The second filter material can comprise paper and / or other biodegradable material that is readily biodegradable. The second filter material can comprise paper and / or other biodegradable material as described above. In some examples, the second filter material comprises uncoated paper, coated paper and / or siliconized paper.

[0025] Preferably, the first filter material comprises paper having a basis weight of 20 gsm to 200 gsm. For example, the paper can have a basis weight of 40 gsm to 180 gsm, such as 60 gsm to 160 gsm, for example 80 gsm to 140 gsm, such as 100 gsm to 120 gsm, for example 20 gsm to 60 gsm, for example 30 gsm to 40 gsm.

[0026] Preferably, the second filter material comprises paper having a basis weight of 20 gsm to 200 gsm. For example, the paper can have a basis weight of 40 gsm to 180 gsm, such as 60 gsm to 160 gsm, for example 80 gsm to 140 gsm, such as 100 gsm to 120 gsm, for example 20 gsm to 60 gsm, for example 30 gsm to 40 gsm.

[0027] Preferably, the length of the element is 18 mm to 60 mm (such as 20 mm to 30 mm, for example 21 mm to 24 mm, such as 25 mm to 40 mm, for example 28 mm).

[0028] Preferably, the first section has a length of 3 mm to 18 mm (such as 6 mm to 12 mm, for example 8 mm to 10 mm).

[0029] Preferably, the second section has a length of 5 mm to 30 mm (such as 8 mm to 25 mm, for example 10 mm to 20 mm).

[0030] Preferably, the cavity has a length of 3 mm to 18 mm (such as 6 mm to 12 mm, for example 8 mm to 10 mm).

[0031] The filter of the application can be cylindrical. Preferably, the circumference of the filter (if cylindrical) is 12 mm to 30 mm (such as 15 mm to 28 mm), more preferably 17 mm to 25 mm (such as 18 mm to 25 mm, for example 20 mm to 24 mm, such as 22 mm to 24 mm, for example 23 mm, such as 22.45 mm).

[0032] Preferably, the longitudinally extending (e.g. cylindrical) core has a uniform axial cross-section (e.g. circular).

[0033] Preferably, the filter (e.g. filter for a tobacco heating product and / or HNB or HTP product) has a substantially circular cross-section, meaning that the filter is substantially cylindrical in shape. However, the filter of the present application can be of any shape. For example, the filter can have an annular cross-section, or an elliptical cross-section, or a square cross-section, or a rectangular cross-section.

[0034] The wrapper (e.g. filter wrapper) that encloses the first segment and the second segment can be a paper material (e.g. cigarette paper), preferably a paper material (e.g. cigarette paper) having a basis weight of 20 gsm to 160 gsm, for example a paper material (e.g. cigarette paper) having a basis weight of 24 gsm to 150 gsm, for example a paper material (e.g. cigarette paper) having a basis weight of 70 gsm to 150 gsm, for example a paper material (e.g. cigarette paper) having a basis weight of 80 gsm to 140 gsm. Preferably, the wrapper (e.g. filter wrapper) that encloses the first segment and the second segment is biodegradable, more preferably readily biodegradable.

[0035] The wrapper (e.g. first segment wrapper) for the first segment (if present) and / or the wrapper (e.g. second segment wrapper) for the second segment (if present) can be a paper material (e.g. cigarette paper). The paper material can be a paper material (e.g. cigarette paper) having a basis weight of 20 gsm to 160 gsm, for example a paper material (e.g. cigarette paper) having a basis weight of 24 gsm to 150 gsm, for example a paper material (e.g. cigarette paper) having a basis weight of 0 gsm to 150 gsm, for example a paper material (e.g. cigarette paper) having a basis weight of 80 gsm to 140 gsm. Preferably, the wrapper (e.g. first segment wrapper) for the first segment (if present) and the wrapper (e.g. second segment wrapper) for the second segment (if present) are biodegradable, more preferably readily biodegradable. The wrapper (e.g. first segment wrapper) for the first segment and the wrapper (e.g. second segment wrapper) for the second segment can be made of the same material or different materials.

[0036] In one example, the filter of the present application has a length of 28 mm and comprises a first segment having a length of 12 mm; a second segment having a length of 8 mm; and a cavity having a length of 8 mm between the first segment and the second segment. This example is illustrated in Figure 1 Fig. 2.

[0037] In another example, a filter according to the present application has a length of 28 mm and comprises a first segment of 8 mm in length; a second segment of 10 mm in length; and a cavity of 10 mm in length between the first and second segments.

[0038] In another example, a filter according to the present application has a length of 28 mm and comprises a first segment of 8 mm in length; a second segment of 10 mm in length; and a cavity of 10 mm in length between the first and second segments.

[0039] In another example, a filter according to the present application has a length of 28 mm and comprises a first segment of 8 mm in length; a second segment of 10 mm in length; and a cavity of 10 mm in length between the first and second segments.

[0040] It will be appreciated that filters according to the present application can be used in any multi-segment filter or consumable. The multi-segment filter can comprise one, two, three, four or more additional discrete segments. These additional further discrete segments can be (e.g. cylindrical) tobacco smoke filter material (e.g. paper) rods and / or hollow (e.g. paper) tube filters. The multi-segment filter can be attached to a tobacco rod (which can be made from any form of tobacco, including reconstituted tobacco). The multi-segment filter can comprise other filter segments, including capsule-containing filters, carbon-containing filters, CPS filters, tube filters, paper filters, menthol-containing filters, and the like.

[0041] It will be appreciated that filters or filter elements according to the present application can be manufactured by methods and machinery well known in the art.

[0042] According to the present application, there is provided a filter element comprising a longitudinally extending (e.g. substantially cylindrical) core having a pressure drop of 0.1 mm WG to 0.5 mm WG per mm of its length (e.g. 0.2 mm WG to 0.3 mm WG per mm of its length, e.g. 0.21 mm WG to 0.29 mm WG per mm of its length, e.g. 0.22 mm WG to 0.25 mm WG per mm of its length, e.g. 0.23 mm WG per mm of its length); the longitudinally extending (e.g. substantially cylindrical) core comprising a filter material comprising paper and / or other biodegradable material (e.g. material free of cellulose acetate) and optionally a wrapper enclosing the longitudinally extending core. Preferably, the longitudinally extending (e.g. substantially cylindrical) core has a pressure drop of 0.2 mm WG to 0.3 mm WG per mm of its length, e.g. 0.21 mm WG to 0.29 mm WG per mm of its length, e.g. 0.22 mm WG to 0.25 mm WG per mm of its length, e.g. 0.23 mm WG per mm of its length. In examples, the longitudinally extending core is formed from paper and / or other biodegradable material which is laterally gathered into a rod form and held in place (e.g. by a wrapper). The longitudinally extending core is formed from paper (e.g. uncoated paper, coated paper, siliconised paper, e.g. ZNP paper) and / or other biodegradable material having a width of 20 mm to 250 mm, e.g. 150 mm to 250 mm, e.g. 151 mm to 250 mm, e.g. 180 mm to 220 mm, e.g. 200 mm which is laterally gathered into a rod form and held in place (e.g. by a wrapper). The filter element has an airflow passage and / or a cooling effect (e.g. on an aerosol drawn through the longitudinally extending core and / or any filter comprising the filter element). It will be appreciated that the term “element” or “filter element” as used herein refers to any discrete segment which can be used in a filter or aerosol-generating article. The element can be a cooling element and / or provide an airflow passage. It will be appreciated that the term “cooling element” as used herein refers to a discrete segment which provides a significant cooling function (i.e. reduces the temperature of an aerosol or vapour as it passes along the length of the element).

[0043] The term "biodegradable" as used herein means that the filter material and filter tip element is capable of exhibiting a biodegradation rate of at least 90% after 6 months under controlled composting conditions (see ISO 14855-1 Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions - Method by analysis of evolved carbon dioxide). Preferably, the paper material and / or other biodegradable material used in the filter material of the (filter tip) element of the present application (e.g. a material free of cellulose acetate) is "readily biodegradable" and has an enhanced biodegradability compared to cellulose acetate. Thus, the present application provides filter tip elements having an enhanced biodegradability, thus being more environmentally friendly and more in line with EU legislation.

[0044] The phrase "readily biodegradable" as used herein means that the filter material and element is capable of rapidly breaking down and fully biodegrading when immersed in water. Preferably, the element has a biodegradability at the "readily biodegradable" level as measured according to the OECD 301 B "ready biodegradability" method (modified Sturm test) as is well known in the art. The phrase "readily biodegradable" is to be understood herein to mean a biodegradability at the "readily biodegradable" level.

[0045] The paper and / or other biodegradable material (e.g. acetate cellulose free filter material) is preferably readily biodegradable. The paper and / or other biodegradable material (e.g. acetate cellulose free filter material) can comprise any paper (in any form) conventionally used in filter tips or filter tip elements. The paper can be, for example, filter paper of different grades, perforated paper, creped paper, air-laid paper or machine glazed paper, etc. The fibres of the paper and / or other biodegradable material (e.g. acetate cellulose free filter material) can be natural fibres (e.g. flax, sisal, jute, abaca, cotton, coconut fibre, bamboo fibre, starch (e.g. from corn) or tobacco) or any rolled material. The paper can be woven or non-woven, or in the form of a bonded paper web, or in the form of a longitudinally corrugated and / or fibrillated paper web, for example laterally gathered into and held in the form of a core rod. The paper and / or other biodegradable material (e.g. acetate cellulose free filter material) can be in the form of a bonded paper web comprising a first paper and / or other biodegradable material (e.g. acetate cellulose free filter material) and a second paper and / or other biodegradable material (e.g. acetate cellulose free filter material). The paper and / or other biodegradable material (e.g. acetate cellulose free filter material) can be in the form of a blend of different paper materials and / or other biodegradable materials (e.g. acetate cellulose free filter material). The paper filter material can have the same or similar structure as those sold under the trademark or (essentra plc (essentra group)).

[0046] The filter material can comprise paper and / or other readily biodegradable biodegradable material. The filter material can comprise paper and / or other biodegradable material as described above. In some examples, the filter material comprises uncoated paper, coated paper and / or siliconised paper. Preferably, the filter material comprises paper having a basis weight of 20 gsm to 200 gsm. For example, the filter material can be paper having a basis weight of 40 gsm to 180 gsm, such as 60 gsm to 160 gsm, for example 80 gsm to 140 gsm, such as 100 gsm to 120 gsm, for example 20 gsm to 60 gsm, for example 30 gsm to 40 gsm. The filter tip element of the present application can be cylindrical. The filter tip element of the present application can be cylindrical, wherein the circumference is 12 mm to 30 mm (e.g. 15 mm to 28 mm), more preferably 17 mm to 25 mm (e.g. 18 mm to 25 mm, for example 20 mm to 24 mm, for example 22 mm to 24 mm, for example 23 mm, for example 22 mm, for example 22.45 mm).

[0047] The wrapper (e.g. core wrapper) engaged around the longitudinally extending core can be a paper material (e.g. cigarette paper), preferably a paper material (e.g. cigarette paper) having a basis weight of 20 gsm to 160 gsm, for example a paper material (e.g. cigarette paper) having a basis weight of 24 gsm to 150 gsm, for example a paper material (e.g. cigarette paper) having a basis weight of 70 gsm to 150 gsm, for example a paper material (e.g. cigarette paper) having a basis weight of 70 gsm to 140 gsm. Preferably, the wrapper (e.g. core wrapper) engaged around the longitudinally extending core is biodegradable, more preferably readily biodegradable.

[0048] The length of the filter element (and the longitudinally extending core) can be 5 mm to 50 mm, for example 17 mm to 35 mm, for example 20 mm to 30 mm, for example 28 mm.

[0049] The paper material and / or other biodegradable material (e.g. cellulose acetate free filtration material) of the longitudinally extending core can be coated with a hydrophobic coating or hydrophobic material, as described above.

[0050] It will be appreciated that the filter element of the present application can be used in any multi-segment filter or consumable. The filter construction can be two, three, four or more discrete segments. These additional discrete segments can be (e.g. cylindrical) tobacco smoke filtration material (e.g. paper) rods and / or hollow (e.g. paper) tube filters. The multi-segment filter can be attached to a tobacco rod (which can be made from any form of tobacco, including reconstituted tobacco). The multi-segment filter can include other filter segments, including capsule-containing filters, carbon-containing filters, CPS filters, tube filters, paper filters, menthol-containing filters, and the like.

[0051] It will be appreciated that the filter or filter element according to the present application can be manufactured by methods and machinery well known in the art.

[0052] According to the present application, in a further aspect, there is provided an aerosol generating article (e.g. a cigarette, for example a tobacco heating product, HNB or HTP product) comprising a filter or filter element according to any aspect of the present application.

[0053] The filter or filter element of the present application is suitable for use with all kinds of tobacco blends.

[0054] In an aerosol-generating article according to the application, the filter of the application (or a filter comprising a filter element of the application) can be connected to a wrapped tobacco rod (e.g. a wrapped modified tobacco rod as is well known in the art). The filter of the application (or a filter comprising a filter element of the application) can be connected to a wrapped tobacco rod such that the (second) segment, which has a pressure drop of 0.1 mm WG to 0.5 mm WG per mm of its length, e.g. 0.2 mm WG to 0.3 mm WG per mm of its length (e.g. 0.23 mm WG per mm of its length), is adjacent to the tobacco rod. The filter can be connected to the wrapped tobacco rod by a ring joint (i.e. an overwrap (e.g. tipping paper) which engages around the adjacent ends of the wrapped filter and tobacco rod only to leave most of the filter overwrap exposed). The filter can be connected to the wrapped tobacco rod by a full joint overwrap (i.e. an overwrap (e.g. tipping paper) which engages around the full length of the wrapped filter and the adjacent ends of the tobacco rod). The overwrap (e.g. filter overwrap) can be ventilated by, for example, laser perforation. Ventilation can be applied to the overwrap (e.g. filter overwrap) before or after the filter is connected to the wrapped tobacco rod. Ventilation can be (applied to the overwrap) aligned with the cavity (if present) in the filter.

[0055] The tobacco heating product and / or HNB or HTP product according to the application can further comprise one or more discrete further segments (e.g. segments of the HNB or HTP mouthpiece). The discrete further segment can be a (e.g. cylindrical) rod of tobacco smoke filter material (e.g. paper), a (e.g. cylindrical) rod of tobacco (e.g. tobacco in any form including reconstituted tobacco), a hollow (e.g. paper) tube, a capsule-containing filter, a carbon-containing filter, a CPS filter, a tube filter, an acetic acid filter, a paper filter, a menthol-containing filter, and the like.

[0056] The application will now be described in more detail with reference to the accompanying drawings, in which:

[0057] Figure 1 A perspective view of a HNB or HTP product according to the application comprising a filter element according to an embodiment of the application is shown;

[0058] Figure 2 is a graphical representation of how the temperature at the mouth end of the HTP product varies with puffing when the HTP product contains a filter A according to the application compared to the reference product TEEA Regular.

[0059] Figure 1A perspective view of one embodiment of a filter for use in an aerosol generating article, such as a tobacco heating product and / or an HNB and / or HTP product, is illustrated. The filter 1 is of a cylindrical shape having a length of 28mm and a circumference of 22.45mm.

[0060] The filter 1 comprises a first segment 3 at the mouth end 2 having a length of 12mm and a circumference of 22.45mm. The first segment 3 is formed from a core rod of a first filtration material in the form of Puracel FM26 paper sheets ([Essentra plc] 300mm FM26g / m 2 SWM) which are gathered together laterally into a core rod form and held in place with a first segment wrap 4 of a non-porous core rod wrap [Mudanjiang Hengfeng Paper Co., Ltd of Mundanjiang, China] having a weight of 78gsm.

[0061] The filter 1 also comprises a second segment 7 which is longitudinally spaced from the first segment 3 by a distance of 8mm. The second segment 7 has a circumference of 22.45mm and a length of 8mm. The second segment 7 comprises a core rod of a second filtration material in the form of ZNP paper sheets (obtained from PT Bukit Muria Jaya (BMJ) of West Java, Indonesia) having a width of 200mm which are gathered together laterally into a rod form and held in place with a second segment wrap 9 of a non-porous core rod wrap [Mudanjiang Hengfeng Paper Co., Ltd of Mundanjiang, China] having a weight of 78gsm. The second segment has a pressure drop of 0.23mm WG per mm of its length.

[0062] A further filter wrap 11 [Mudanjiang Hengfeng Paper Co., Ltd of Mundanjiang, China] of a hard core rod wrap having a weight of 78g / m 2 of 8mm is defined between the wrapped segments 3 and 7. The two ends of the filter wrap 11 are flush with the ends of the wrapped segments 3 and 7. The filter wrap 11 has overlapping longitudinal edges on which is applied an adhesive which provides a lap and bond seam (not shown) that holds the filter wrap 11 around the wrapped segments 3 and 7 in place and a further adhesive is applied on anchor lines (not shown) aligned with the wrapped segments 3 and 7 to hold these segments in place.

[0063] The first section 3 and the second section 7, their respective first section wrappers 4 and second section wrappers 9, and the filter wrapper 11 are all made of paper material and are "readily biodegradable", which means that they are able to quickly decompose and completely biodegrade when immersed in water, so that the filter 1 (and the materials therein) have a "readily biodegradable" level of biodegradability as measured according to the OECD 301B "readily biodegradable" method (modified Sturm test) which is well known in the art.

[0064] Applicants have surprisingly discovered that filters such as Filter 1 combine biodegradability ("readily biodegradable") with comparable thermal profiles and / or comparable aerosol chemical delivery to commercially available products using cellulose acetate and PLA (see Example 1 below). Further, Applicants have discovered that the filters of the present invention can be adapted to provide customizable designs to match a desired aerosol chemical delivery profile.

[0065] It should be understood that the filter 1 can be made by methods known in the art and can be prepared as a multi-rod comprising a plurality of (eg, 2, 4, 6, etc.) filter rods or filter rods integrally connected end to end.

[0066] By methods well known in the art, the filter 1 can be connected to a wrapped modified tobacco plug at the end opposite to the mouth end 2, and the plug includes a metal element for induction heating. Suitable reconstituted tobacco plugs (including metal elements for induction heating) are 12 mm long and have a circumference of 22 mm. Such reconstituted tobacco plugs are well known in the art. The filter and tobacco plug together form an HTP comprising the filter 1 of the present invention.

[0067] In use, the tobacco plug end of the HTP comprising the filter 1 of the present invention is inserted into the HTP device. The plug is heated by a heating device (HTP device) in use to generate steam, as is well known in the art. This produces hot steam, which is first extracted through the second section 7, through the cavity 13, and reaches the smoker's mouth (i.e., mouth end) through the first section 3. It is believed that the second section 7, which is 0.23 mm WG per mm of its length, draws this hot steam and draws it into the cavity 13 to mix with air, has a cooling effect (e.g., a cooling effect on the aerosol extracted by the second section and / or the filter), and this cooling effect cools the steam to a temperature acceptable to the user. The second section 7 provides an airflow path for the steam.

[0068] Experiment

[0069] Will be referenced Figure 1The exemplified HTP according to the application of length 28 mm (comprising a first segment of length 12 mm (FM26 paper); a second segment of length 8 mm (ZNP paper); and a cavity of length 8 mm between the first and second segments) was attached to a reconstituted tobacco rod comprising a metal element for induction heating by methods known in the art to provide the HTP for testing. This is referred to as test example ZCP111541.

[0070] Reference product TEREA Regular comprises a reconstituted tobacco rod comprising a metal element for induction heating, an 8 mm regular acetate tube (tobacco end), a 12 mm single acetate filter at the mouth end and an 8 mm thin walled hollow acetate tube between the regular acetate tube and the single acetate filter, configured similarly to the configuration of Figure 1

[0071] HTP test example and TEREA Regular reference product comparison is as follows:

[0072] Each HTP product was inserted into a heating device. The mouth end of the HTP product was inserted into a smoking machine configured to draw on the HTP. As the product was smoked, an IR camera was used to analyse the temperature at the mouth end of the product. The smoking machine was configured to make one draw on the product every 30 seconds, each draw being 2 seconds long. The temperature at the mouth end of the product was measured at each draw. The experiment was carried out at standard room temperature and humidity. The experiment was repeated for each example product, ZCP111541 and reference product TEREA Regular.

[0073] Figure 2 A comparison of the temperature at the mouth end at each draw for ZCP111541 and reference product TEREA Regular is exemplified. The graph shows that the paper-based ZCP111541 of the application is able to provide a cooling effect equivalent to a regular cooling element, whilst providing the significant benefit of being readily biodegradable.

[0074] Temperature change and nicotine yield of example HTP product ZCP111541 and reference product TEREA Regular in a regular heating device (HNB device) was measured by methods well known in the art (ISO 3308:2012 Routine analytical cigarette-smoking machine - Definitions and standard conditions). The results are shown in Table 1.

[0075] Table 1 ​

[0076]

[0077] Table 1 shows that filter and elements according to the application can provide a thermal profile and / or comparable aerosol chemical delivery performance to conventional cooling elements (reference) while also providing improved biodegradability (as they do not comprise e.g. PLA elements).

Claims

1. A filter for use in an aerosol-generating article, the filter comprising a first segment and a second segment constituting a longitudinally extending core; wherein the first segment comprises a first filter material; wherein the second segment comprises a second filter material having a pressure drop of 0.1 mm WG to 0.5 mm WG per mm of its length (for example 0.2 mm WG to 0.3 mm WG per mm of its length, for example 0.21 mm WG to 0.29 mm WG per mm of its length, for example 0.22 mm WG to 0.25 mm WG per mm of its length, for example 0.23 mm WG per mm of its length); the filter further comprising a wrapper enclosing the longitudinally extending core; wherein the first filter material and the second filter material comprise paper and / or other biodegradable material.

2. A filter according to claim 1, wherein the second segment is formed from paper and / or other biodegradable material which is laterally gathered into a rod form and held in place (for example by a wrapper).

3. A filter according to claim 1 or 2, wherein the first segment is longitudinally separated from the second segment such that the wrapper is within the longitudinally extending core, defining a longitudinal cavity between the first segment and the second segment.

4. A filter according to any preceding claim, wherein the wrapper provides a ventilation means.

5. A filter according to claim 4, wherein the ventilation means is provided by one or more perforations in the wrapper aligned with the cavity.

6. A filter according to any preceding claim wherein the second segment has a paper density of 0.18 g / cm 3 to 0.28 g / cm 3 , for example 0.19 g / cm 3 to 0.26 g / cm 3 , for example 0.2 g / cm 3 to 0.25 g / cm 3 , for example 0.211 g / cm 3 .

7. A filter according to any preceding claim, wherein the biodegradable material is readily biodegradable.

8. A filter according to any preceding claim, wherein the second segment is formed from paper and / or other biodegradable material having a width of 20 mm to 250 mm, for example 180 mm to 230 mm, for example 200 mm, which is laterally gathered into a rod form and held in place (for example by a wrapper).

9. A filter according to any preceding claim, wherein the first segment has a length of 3 mm to 18 mm, for example 6 mm to 12 mm, for example 8 mm to 10 mm.

10. A filter according to any preceding claim, wherein the second segment has a length of 5 mm to 30 mm, for example 8 mm to 25 mm, for example 10 mm to 20 mm.

11. A filter according to any preceding claim, wherein the cavity has a length of 3 mm to 18 mm, for example 6 mm to 12 mm, for example 8 mm to 10 mm.

12. A filter according to any preceding claim, wherein the filter has a length of 5 mm to 60 mm, for example 10 mm to 55 mm, for example 15 mm to 30 mm.

13. A filter according to any preceding claim, wherein the element has a circumference of 12 mm to 30 mm, for example 15 mm to 28 mm, for example 17 mm to 25 mm.

14. A filter element comprising a longitudinally extending (e.g. substantially cylindrical) core having a pressure drop of 0.1 mm WG to 0.5 mm WG per mm of its length (e.g. 0.2 mm WG to 0.3 mm WG per mm of its length, e.g. 0.21 mm WG to 0.29 mm WG per mm of its length, e.g. 0.22 mm WG to 0.25 mm WG per mm of its length, e.g. 0.23 mm WG per mm of its length); the longitudinally extending (e.g. substantially cylindrical) core comprising a filter material comprising paper and / or other biodegradable material (e.g. material free of cellulose acetate) and optionally a wrapper enclosing the longitudinally extending core.

15. A filter element according to claim 14, wherein the longitudinally extending core is formed from paper and / or other biodegradable material which is laterally gathered into a rod form and held in place (e.g. by a wrapper).

16. A filter element according to claim 14 or claim 15, wherein the longitudinally extending core is formed from paper and / or other biodegradable material having a width of 10 mm to 250 mm, e.g. 20 mm to 250 mm, e.g. 151 mm to 250 mm, e.g. 180 mm to 220 mm, e.g. 200 mm, which is laterally gathered into a rod form and held in place (e.g. by a wrapper).

17. An aerosol generating article (e.g. tobacco heating product, HNB product, HTP) comprising a filter according to any one of claims 1 to 13 or comprising a filter comprising a filter element according to any one of claims 14 to 16 and optionally one or more further segments.

18. A tobacco heating product and / or HNB product and / or HTP comprising a filter according to any one of claims 1 to 13 or comprising a filter comprising a filter element according to any one of claims 14 to 16 and optionally one or more further segments.

19. Use of a filter according to any one of claims 1 to 13 or a filter comprising a filter element according to any one of claims 14 to 16 in a tobacco heating product and / or HNB product and / or HTP.

20. A filter substantially as hereinbefore described with reference to Figure 1 or Figure 2 of the accompanying drawings.

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