A SUSTAINABLE FILTER OR FILTER ELEMENT

Description

INTRODUCTION

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 heated tobacco product.

BACKGROUND

Tobacco heating products or heat-not-burn (HNB) products (also known as heated tobacco products or HTP products) are well known. The idea of a tobacco heating product is that the tobacco is heated 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 creation of combustion products that are harmful to the consumer.

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

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

However, cellulose acetate and PLA are not readily biodegradable. As a result, aerosol generating article elements such as cellulose acetate containing filter elements and cooling elements may persist in the environment for many years. Due to this, and in consideration of new EU legislation coming into force by 2021 (aimed at reducing the use of single-use plastics such as cellulose acetate filters), there is increasing interest in filters and filter elements that do not comprise single-use plastics and are readily biodegradable.

Consequently, there is a need for a filter or filter element that provides acceptable cooling of the vapour in a HTP product and acceptable filtration properties while having an improved biodegradability to conventional materials such as cellulose acetate.

SUMMARY OF THE INVENTION

According to the present invention 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 heated product and/or HNB/HTP product), the filter comprising first and second segments making up a longitudinally extending (e.g., cylindrical) core; wherein the first segment comprises a first filtering material; wherein the second segment comprising a second filtering material which has (e.g. provides) a pressure drop from 0.1 to 0.5 mmWG per mm of its length (for example 0.15 to 0.45 mmWG of its length, for example from 0.2 to 0.3 mmWG per mm of its length, for example a pressure drop from 0.21 to 0.29 mmWG per mm of its length, for example a pressure drop from 0.22 to 0.25 mmWG per mm of its length, for example a pressure drop of 0.23 mmWG per mm of its length); the filter further comprising a wrapper (e.g. filter wrapper) encasing the longitudinally extending core; wherein the first and second filtering materials comprise paper and/or other biodegradable material. Preferably the second filtering material has a pressure drop from 0.2 to 0.3 mmWG per mm of its length, for example a pressure drop from 0.21 to 0.29 mmWG per mm of its length, for example a pressure drop from 0.22 to 0.25 mmWG per mm of its length, for example a pressure drop of 0.23 mmWG per mm of its length.

In some examples of the filter, the first segment is distanced longitudinally from the second segment such that the wrapper defines a cavity between the first and second segments.

The first segment may be formed from a paper (e.g. Puracel FM26, Puracel FM36 and/or Greenbutts) and/or other biodegradable material which is gathered laterally into rod form and held in place (e.g. by a wrapper, e.g. by a first segment wrapper). It will be appreciated that the first segment may have a wrapper (e.g. first segment wrapper) which holds the filtering material in shape (e.g. in core form, e.g. in rod or plug form). This wrapper (e.g. first segment wrapper) is e.g. separate from the wrapper (e.g. filter wrapper) which is engaged around the first and second segments. If there is a wrapper (e.g. first segment wrapper) for the first segment, it will be appreciated that the wrapper (e.g. filter wrapper) encasing the first and second segments is wrapped around the wrapper (e.g. first segment wrapper) of the first segment as well as the first segment itself.

The second segment may be formed from a paper (e.g. uncoated paper, coated paper, siliconized paper, e.g. ZNP paper) and/or other biodegradable material which is gathered laterally into rod form and held in place (e.g. by a wrapper, e.g. a second core wrapper). The second segment may be formed from a paper (e.g. uncoated paper, coated paper, siliconized paper, e.g. ZNP paper) and/or other biodegradable material of width 20 to 250 mm, for example 151 to 250 mm, for example 180 to 220 mm, for example 200 mm, which is gathered laterally into 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 may have a wrapper (e.g. second segment wrapper) which holds the filtering material in shape (e.g. in core form, e.g. in rod or plug form). This wrapper (e.g. second segment wrapper) is e.g. separate from the wrapper (e.g. filter wrapper) which is engaged around the first and second segments. If there is a wrapper (e.g. second segment wrapper) for the second segment, it will be appreciated that the wrapper (e.g. filter wrapper) engaged around the first and segments is wrapped around the wrapper (e.g. second segment wrapper) of the second segment as well as the second segment itself.

The applicants have surprisingly found that filters according to aspects the invention combine biodegradability (are “readily biodegradable”) with a comparable thermal profile and/or comparable Aerosol Chemistry Delivery to the product in the market which uses cellulose acetate and PLA. Further, the applicants have found the filters of the invention are adaptable to provide a customizable design to match a desired aerosol chemistry delivery profile.

Preferably, the wrapper (e.g. filter wrapper) defines a longitudinal cavity within the longitudinally extending core, between the first and second segments. The applicant has found that this can allow the aerosol to mix with air which could reduce the temperature of the aerosol. The filter wrapper may be a paper (e.g., plugwrap), preferably a paper (e.g., plugwrap) of basis weight 20 to 160 gsm, for example a paper (e.g., plugwrap) of basis weight 24 to 150 gsm, for example a paper (e.g., plugwrap) of basis weight 70 to 150 gsm, for example a paper (e.g., plugwrap) of basis weight 70 to 140 gsm.

Preferably, the wrapper (e.g. filter wrapper) provides means of ventilation. Preferably the means of ventilation is provided by one, or a plurality of, perforations in the wrapper (e.g. filter wrapper). Preferably the means of ventilation is in register with the cavity. The applicant has found that ventilation may allow external air to enter the cavity which can help in reducing the aerosol temperature.

Preferably, the second segment has a paper density from 0.18 to 0.28 g/cm³, for example 0.19 to 0.26 g/cm³, for example 0.2 to 0.25 g/cm³, for example 0.211 g/cm³.

The first filtering material may comprise a paper and/or other biodegradable material which is readily biodegradable. The second filtering material may comprise a paper and/or other biodegradable material which is readily biodegradable. Preferably, each of the first and second filtering materials comprise a paper and/or other biodegradable material which is readily biodegradable.

The term “biodegradable” refers to the filtering material and element being able to exhibit a biodegradation of at least 90% after 6 months under controlled composting conditions (see ISO14855-1 Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions-Method by analysis of evolved carbon dioxide).

Preferably, the paper and/or other biodegradable material (e.g. non-cellulose acetate containing material) used in the filtering material(s) of the filter of the present invention is “readily biodegradable” and has an enhanced biodegradability compared to cellulose acetate. Therefore, the present invention provides an element of enhanced biodegradability, and thus is more environmentally friendly and is more in line with EU legislation.

The phrase “readily biodegradable” refers to the filtering material and filter being able to disintegrate rapidly and completely biodegrade when immersed in water. Preferably the element has the ‘Ready Biodegradability’ level of biodegradability as measured according to OECD 301B ‘Ready Biodegradability’ method (modified Sturm test), which is well known in the art. The phase “readily biodegradable” will here be understood to mean ‘Ready Biodegradability’ level of biodegradability.

The paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) is preferably readily biodegradable. The paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) may be comprised of any paper (in any form) which is conventionally used in filters or filter elements. The paper may be, for example, filtering paper, aperture paper, crepe paper, air-laid paper or machine glazed paper etc. of varying grades. The fibre of the paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) may be a natural fibre (e.g. flax, hemp, sisal, jute, abaca, cotton, coconut fibres, bamboo fibres, starch (e.g. from corn), or tobacco) or any roll material. The paper may be woven or non-woven, or in the form of a coherent web of paper, or a longitudinally corrugated and/or fibrillated web of paper e.g. gathered laterally into, and held, in plug form. The paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) may be in the form of a coherent web comprising a first paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) and a second paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material). The paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) may be in the form of a blend of different paper materials and/or other biodegradable materials (e.g. non-cellulose acetate containing filtering materials). The paper filtering material may have the same or a similar structure to those papers sold under the trademark Myria® or Puracel® (of Essentra plc). The paper may be coated with a hydrophobic coating or hydrophobic material.

If present, the hydrophobic coating/material may be any suitable hydrophobic material. For example, the hydrophobic coating/material may a polymer or a blend of polymers. Preferably, the hydrophobic coating/material is a starch, such as a modified starch, for example oxidized starch (E1404). A starch such as a modified starch is preferred as it is inert and provides a non-plastic hydrophobic coating. The hydrophobic coating/material may be present in an amount from 0.01% to 50% weight of hydrophobic coating/material with respect to weight of the element (w/w), 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.

A coated paper according to the present invention 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.

The first filtering material may comprise a paper and/or other biodegradable material which is readily biodegradable. The first filtering material may comprise a paper and/or other biodegradable material as set out in the paragraph above. In some examples, the first filtering material comprises Puracel FM26, Puracel FM36 and/or Greenbutts.

The second filtering material may comprise a paper and/or other biodegradable material which is readily biodegradable. The second filtering material may comprise a paper and/or other biodegradable material as described above. In some examples, the second filtering material comprises Uncoated Paper, Coated Paper and/or Siliconized Paper.

Preferably, the first filtering material comprises paper having a basis weight from 20 gsm to 200 gsm. For example, the paper may have a basis weight from 40 gsm to 180 gsm, e.g. from 60 gsm to 160 gsm, e.g. from 80 gsm to 140 gsm, e.g. from 100 gsm to 120 gsm, e.g. from 20 gsm to 60 gsm, e.g. from 30 gsm to 40 gsm.

Preferably, the second filtering material comprises paper having a basis weight from 20 gsm to 200 gsm. For example, the paper may have a basis weight from 40 gsm to 180 gsm, e.g. from 60 gsm to 160 gsm, e.g. from 80 gsm to 140 gsm, e.g. from 100 gsm to 120 gsm, e.g. from 20 gsm to 60 gsm, e.g. from 30 gsm to 40 gsm.

Preferably the length of the element is from 18 to 60 mm (e.g., from 20 to 30 mm, e.g., 21 to 24 mm, e.g., 25 to 40 mm, e.g., 28 mm).

Preferably the first segment has a length from 3 mm to 18 mm (e.g., 6 mm to 12 mm, e.g., 8 mm to 10 mm).

Preferably the second segment has a length from 5 mm to 30 mm (e.g., 8 mm to 25 mm, e.g., 10 mm to 20 mm).

Preferably the cavity has a length from 3 mm to 18 mm (e.g., 6 mm to 12 mm, e.g., 8 mm to 10 mm).

The filter of the invention may be cylindrical. Preferably the circumference of the filter (if cylindrical) is from 12 to 30 mm (e.g., 15 to 28 mm), more preferably from 17 to 25 mm, (e.g., 18 to 25 mm, e.g., 20 to 24 mm, e.g., 22 to 24 mm, e.g., 23 mm, e.g., 22.45 mm).

Preferably the longitudinally extending (e.g., cylindrical) core is of uniform axial cross section (e.g., circular).

Preferably the filter (e.g., a filter for a tobacco heating product and/or HNB OR HTP product) has a substantially circular cross section meaning the filter is substantially cylindrical in shape. However, the filter of the present invention may be any shape. For example, the filter may have an annular cross section or an oval cross section or a square cross section or a rectangular cross section.

The wrapper (e.g. filter wrapper) encasing the first and second segments may be a paper (e.g., plugwrap), preferably a paper (e.g., plugwrap) of basis weight 20 to 160 gsm, for example a paper (e.g., plugwrap) of basis weight 24 to 150 gsm, for example a paper (e.g., plugwrap) of basis weight 70 to 150 gsm, for example a paper (e.g., plugwrap) of basis weight 80 to 140 gsm. Preferably the wrapper (e.g. filter wrapper) encasing the first and second segments is biodegradable, more preferably readily biodegradable.

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

In one example, the filter of the invention is of length 28 mm and comprises a first segment of length 12 mm; a second segment of length 8 mm; and a cavity between the first and second segments of length 8 mm. This example is illustrated in attached FIG. 1.

In another example, the filter of the invention is of length 28 mm and comprises a first segment of length 8 mm; a second segment of length 10 mm; and a cavity between the first and second segments of length 10 mm.

In a further example, the filter of the invention is of length 28 mm and comprises a first segment of length 10 mm; a second segment of length 8 mm; and a cavity between the first and second segments of length 8 mm.

In a further example, the filter of the invention is of length 28 mm and comprises a first segment of length 8 mm and a second segment of length 20 mm.

It will be appreciated that the filter of the invention may be used in any multi-segment filter or consumable. The multi-segment filter may comprise one, two, three, four or more additional discrete segments. The additional discrete further segments may be (e.g., cylindrical) plugs of tobacco smoke filtering material (e.g., paper) and/or a hollow (e.g., paper) tube filter. The multi-segment filter may be attached to a tobacco plug (which can be made from any form of tobacco (including reconstituted)). The multi-segment filter may include other filter segments that include capsule containing filters, carbon containing filters, CPS filters, tube filters, paper filters, menthol containing filters etc.

It will be appreciated that filters or filter elements according to the invention may be manufactured by methods and machinery well known in the art.

According to the present invention there is provided a filter element comprising a longitudinally extending (e.g. substantially cylindrical) core having a pressure drop from 0.1 to 0.5 mmWG per mm of its length (for example a pressure drop from 0.2 to 0.3 mmWG per mm of its length, for example a pressure drop of 0.21 to 0.29 mmWG per mm of its length, for example a pressure drop from 0.22 to 0.25 mmWG per mm of its length, for example a pressure drop of 0.23 mmWG per mm of its length); the longitudinally extending (e.g. substantially cylindrical) core comprising a filtering material comprising paper and/or other biodegradable material (e.g. non-cellulose acetate containing material) and optionally a wrapper encasing the longitudinally extending core. Preferably the longitudinally extending (e.g. substantially cylindrical) core has a pressure drop from 0.2 to 0.3 mmWG per mm of its length, for example a pressure drop from 0.21 to 0.29 mmWG per mm of its length, for example a pressure drop from 0.22 to 0.25 mmWG per mm of its length, for example a pressure drop of 0.23 mmWG per mm of its length. In examples, the longitudinally extending core is formed from paper and/or other biodegradable material which is gathered laterally into rod form and held in place (e.g. by a wrapper). The longitudinally extending core is formed from a paper (e.g. uncoated paper, coated paper, siliconized paper, e.g. ZNP paper) and/or other biodegradable material of width 20 to 250 mm, for example 150 to 250 mm, for example 151 to 250 mm, for example 180 to 220 mm, for example 200 mm, which is gathered laterally into rod form and held in place (e.g. by a wrapper). The filter element has airflow pathways and/or a cooling effect (e.g. on aerosol drawn through the longitudinally extending core and/or any filter including the filter element). It will be appreciated that the term “element” or “filter element” as used herein refers to any discrete segment that can be used in a filter or aerosol generating article. The element may be a cooling element and/or provide airflow pathways. 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., lowering the temperature of aerosol or vapour as it passes along the length of the element.

The term “biodegradable” as used herein refers to the filtering material and filter element being able to exhibit a biodegradation of at least 90% after 6 months under controlled composting conditions (see ISO14855-1 Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions-Method by analysis of evolved carbon dioxide). Preferably, the paper and/or other biodegradable material (e.g. non-cellulose acetate containing material) used in the filtering material of the (filter) element of the present invention is “readily biodegradable” and has an enhanced biodegradability compared to cellulose acetate. Therefore, the present invention provides a filter element of enhanced biodegradability, and thus is more environmentally friendly and is more in line with EU legislation.

The phrase “readily biodegradable” as used herein refers to the filtering material and element being able to disintegrate rapidly and completely biodegrade when immersed in water. Preferably the element has the ‘Ready Biodegradability’ level of biodegradability as measured according to OECD 301B ‘Ready Biodegradability’ method (modified Sturm test), which is well known in the art. The phase “readily biodegradable” will here be understood to mean ‘Ready Biodegradability’ level of biodegradability.

The paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) is preferably readily biodegradable. The paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) may be comprised of any paper (in any form) which is conventionally used in filters or filter elements. The paper may be, for example, filtering paper, aperture paper, crepe paper, air-laid paper or machine glazed paper etc. of varying grades. The fibre of the paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) may be a natural fibre (e.g. flax, hemp, sisal, jute, abaca, cotton, coconut fibres, bamboo fibres, starch (e.g. from corn), or tobacco) or any roll material. The paper may be woven or non-woven, or in the form of a coherent web of paper, or a longitudinally corrugated and/or fibrillated web of paper e.g. gathered laterally into, and held, in plug form. The paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) may be in the form of a coherent web comprising a first paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) and a second paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material). The paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) may be in the form of a blend of different paper materials and/or other biodegradable materials (e.g. non-cellulose acetate containing filtering materials). The paper filtering material may have the same or a similar structure to those papers sold under the trademark Myria® or Puracel® (of Essentra plc).

The filtering material may comprise a paper and/or other biodegradable material which is readily biodegradable. The filtering material may comprise a paper and/or other biodegradable material described above. In some examples, the filtering material comprises Uncoated Paper, Coated Paper and/or Siliconized Paper. Preferably, the filtering material comprises a paper having a basis weight from 20 gsm to 200 gsm. For example, the filtering material may be a paper having a basis weight from 40 gsm to 180 gsm, e.g. from 60 gsm to 160 gsm, e.g. from 80 gsm to 140 gsm, e.g. from 100 gsm to 120 gsm, e.g. from 20 gsm to 60 gsm, e.g. from 30 gsm to 40 gsm. The filter element of the invention may be cylindrical.

The filter element of the invention may be cylindrical with circumference from 12 to 30 mm (e.g., 15 to 28 mm), more preferably from 17 to 25 mm, (e.g., 18 to 25 mm, e.g., 20 to 24 mm, e.g., 22 to 24 mm, e.g., 23 mm, e.g., 22 mm, e.g. 22.45 mm).

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

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

The paper and/or other biodegradable material (e.g. non-cellulose acetate containing filtering material) of the longitudinally extending core may be coated with a hydrophobic coating or hydrophobic material, as described above.

It will be appreciated that the filter element of the invention may be used in any multi-segment filter or consumable. The filter construction could be two, three, four or more discrete segments. The discrete further segments may be (e.g., cylindrical) plugs of tobacco smoke filtering material (e.g., paper) and/or a hollow (e.g., paper) tube filter. The multi-segment filter may be attached to a tobacco plug (which can be made from any form of tobacco (including reconstituted)). The multi-segment filter may include other filter segments that include capsule containing filters, carbon containing filters, CPS filters, tube filters, paper filters, menthol containing filters etc.

It will be appreciated that filters or filter elements according to the invention may be manufactured by methods and machinery well known in the art.

According to the present invention in a further aspect there is provided an aerosol generating article (e.g. cigarette, e.g. tobacco heat product, HNB or HTP product) comprising a filter or filter element according to any aspect of the invention.

The filter or filter element of the present invention is suitable for use with all varieties of tobacco blends.

In an aerosol generating article according to the invention, a filter of the invention (or a filter which includes a filter element of the invention) may be joined to a wrapped plug of tobacco (e.g. wrapped plug of modified tobacco, as is well known in the art). The filter of the invention (or filter which includes a filter element of the invention) may be joined to the wrapped tobacco plug such that the (second) segment which has a pressure drop of from 0.1 to 0.5 mmWG per mm of its length, for example 0.2 to 0.3 mmWG per mm (e.g. 0.23 mmWG per mm) of its length is adjacent the tobacco plug. The filter may be joined to the wrapped tobacco plug by ring tipping (i.e. an outer wrapper (e.g. tipping paper) which engages around just the adjacent ends of the wrapped filter and the tobacco plug to leave much of the filter wrap exposed). The filter may be joined to the wrapped tobacco plug by a full tipping overwrap (i.e. an outer wrapper (e.g. tipping paper) which engages around the full wrapped filter length and the adjacent end of the tobacco plug). The wrapper (e.g. filter wrapper) may be ventilated by e.g. laser perforations. The ventilation may be applied to the wrapper (e.g. filter wrapper) before or after the filter is joined to the wrapped tobacco plug. The ventilation may be (applied to the wrapper) in register with the cavity in the filter (if present).

The tobacco heating product and/or HNB or HTP product according to the present invention may further comprise one or more discrete further segments (e.g., of a HNB or HTP mouthpiece). The discrete further segments may be (e.g., cylindrical) plugs of tobacco smoke filtering material (e.g., paper), a (e.g., cylindrical) rod of tobacco (e.g., any form of tobacco (including reconstituted tobacco)), hollow (e.g., paper) tubes, capsule containing filters, carbon containing filters, CPS filters, tube filters, acetate filters, paper filters, menthol containing filters etc.

The present invention will now be described in further detail by reference to the attached Figures in which:

FIG. 1 shows a perspective view of a HNB or HTP product according to the invention which includes a filter element according to an embodiment of the invention;

FIG. 2 is a graphical representation of how the temperature at the mouth end of a HTP product varies as puffs are taken when the HTP product contains filter A according to the present invention in comparison with a reference product, TEREA Regular.

FIG. 1 illustrates a perspective view of one embodiment of a filter for use in an aerosol generating article (e.g. a tobacco heated product and/or a HNB or HTP product). The filter 1 is cylindrical in shape with a length 28 mm and a circumference 22.45 mm.

The filter 1 includes, at the mouth end 2, a first segment 3 of length 12 mm and circumference 22.45 mm. The first segment 3 is formed from a plug of a first filtering material in the form of a sheet of Puracel FM26 paper (300 mm Puracel® FM26 g/m² SWM [of Essentra plc]) which is gathered together laterally into plug form and held in place with a first segment wrapper 4 of non-porous plug wrap [Mudanjiang Hengfeng Paper Co., Ltd of Mundanjiang, China] of 78 gsm weight.

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

A further filter wrapper 11 of stiff plug wrap of 78 g/m² weight [Mudanjiang Hengfeng Paper Co., Ltd of Mundanjiang, China] encases the wrapped segments 3 and 7 to define a cavity 13 of length 8 mm between the wrapped segments 3 and 7. Both ends of the filter wrapper 11 are flush with the ends of wrapped segments 3 and 7. The filter wrapper 11 has an overlapping longitudinal edge with adhesive applied thereon which provides a lapped and stuck seam (not shown) holding the filter wrapper 11 around the wrapped segments 3 and 7 and a further adhesive in anchor lines (not shown) in register with the wrapped segments 3 and 7 to hold the segments in place.

The first and second segments 3 and 7, their respective first segment wrapper 4 and second segment wrapper 9, and the filter wrapper 11, are all made of paper material and are all “readily biodegradable”, meaning they are able to disintegrate rapidly and completely biodegrade when immersed in water, such that filter 1 (and materials therein) have the ‘Ready Biodegradability’ level of biodegradability as measured according to OECD 301B ‘Ready Biodegradability’ method (modified Sturm test), which is well known in the art.

The applicants have surprisingly found that filters such as filter 1 combine biodegradability (are “readily biodegradable”) with a comparable thermal profile and/or comparable Aerosol Chemistry Delivery to the product in the market which uses cellulose acetate and PLA (see Example 1 below). Further the applicants have found the filters of the invention are adaptable to provide a customizable design to match a desired aerosol chemistry delivery profile.

It will be appreciated that the filter 1 may be made by methods known in the art and may be prepared as a multiple rod comprising a plurality (e.g. 2, 4, 6 etc.) of filters or filter rods integrally joined end-to-end.

The filter 1 may be joined, at the end opposite to mouth end 2, to a wrapped plug of modified tobacco comprising a metal element for induction heating, by methods well known in the art. A suitable plug of reconstituted tobacco comprising a metal element for induction heating is 12 mm long and has a circumference of 22 mm. Such plugs of reconstituted tobacco are well known in the art. Together the filter and plug of tobacco form a HTP including filter of the invention 1.

In use, the tobacco plug end of a HTP including filter of the invention 1 is inserted in a HTP device. This plug is heated in use by a heating device (HTP device) to produce a vapour, as is well known in the art. This produces a hot vapour which is first drawn through the second segment 7, through the cavity 13, and through the first segment 3 to the smoker's mouth (i.e., the mouth end). It is believed that drawing this hot vapour through the second segment 7 of pressure drop 0.23 mmWG per mm of its length and into the cavity 13 to mix with air has a cooling effect (e.g. on aerosol drawn through the second segment and/or the filter) which cools the vapour down to a temperature that is acceptable for the user. The second segment 7 provides airflow pathways for the vapour.

Experiment

A HTP according to the invention as illustrated with reference to FIG. 1 of length 28 mm including a first segment of length 12 mm (FM26 paper); a second segment of length 8 mm (ZNP paper); and a cavity between the first and second segments of length 8 mm, was attached to a plug of reconstituted tobacco comprising a metal element for induction heating by methods well known in the art to provide a HTP for testing. This is referred to as test Example ZCP111541.

The reference product TEREA Regular included a plug of reconstituted tobacco comprising a metal element for induction heating, a 8 mm regular acetate tube (tobacco end), a 12 mm mono acetate filter at the mouth end and a 8 mm thin walled hollow acetate tube between the regular acetate tube and mono acetate filter, in an analogous configuration to that of FIG. 1.

The HTP test example and the TEREA Regular reference product were compared as follows:

Each HTP product was inserted into a heating device. The mouth end of the HTP product was inserted into a smoking machine which is configured to smoke the HTP. An IR camera was used to analyse the temperature at the mouth end of the product while it was being smoked. The smoking machine was configured to take a puff on the product every 30 seconds, each puff being 2 seconds long. The temperature at the mouth end of the product was measured for each puff. The experiment was performed at standard room temperature and humidity. The experiment was repeated for each example product i.e. ZCP111541 and the reference product TEREA Regular.

FIG. 2 illustrates the temperature at the mouth end for each puff for ZCP111541 in comparison with the reference product TEREA Regular. The Figure shows that paper based ZCP111541 of the present invention is capable of providing a cooling effect that is equivalent to conventional cooling elements, while providing the huge benefit of being readily biodegradable.

The temperature change and nicotine yield of the example HTP product ZCP111541 and the reference product TEREA Regular in conventional heating devices (HNB devices) were measured by methods well known in the art (ISO 3308:2012 Routine analytical cigarette-smoking machine-Definitions and standard conditions). The results are illustrated in Table 1.

Table 1 shows that the filters and elements according to the present invention may provide comparable thermal profile and/or comparable Aerosol Chemical Delivery performance to conventional cooling elements (the reference), while also providing improved biodegradability (due to not containing e.g. PLA elements).