Double-layer composite filter stick and aerosol generating product

Abstract

The invention belongs to the technical field of cigarette filter sticks, and particularly relates to a double-layer composite filter stick and an aerosol generating product. The invention provides a double-layer composite filter stick. The double-layer composite filter stick comprises a porous adsorption layer and a bacteriostatic functional layer, the porous adsorption layer comprises a softwood pulp fiber net and adsorbent particles dispersed in the softwood pulp fiber net; the antibacterial functional layer comprises a nanofiber membrane and further comprises lignosulfonate dispersed in the nanofiber membrane; the porous adsorption layer and the antibacterial functional layer are sequentially overlapped, molded and cut to form the double-layer composite filter stick. The invention also provides an aerosol generating article. According to the invention, the fiber ratio and dispersion process of dry papermaking are optimized, and uniform distribution of additives such as activated carbon and the like is ensured; a double-layer composite structure design is adopted, and an independent antibacterial functional layer is constructed through an electrostatic spinning technology. The environment-friendly characteristic of a paper material is reserved, and the technical problem of basic filtering to multifunctional integration is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of filter rods for cigarettes, and particularly relates to a double-layer composite filter rod and an aerosol generating product. Background Art

[0002] Traditional cigarette filter rods primarily use cellulose acetate (cellulose diacetate) as a base material. While this material offers excellent filtration performance and processing characteristics, its production process presents significant environmental issues. The production of cellulose acetate relies on chemical raw materials such as wood pulp and acetic anhydride, which not only consumes significant amounts of forest resources but also produces acidic wastewater during production, which is costly to treat and easily causes environmental pollution. Furthermore, cellulose acetate filter rods are difficult to degrade in the natural environment, and discarded filters have become a global source of microplastic pollution. With increasingly stringent environmental regulations and rising consumer awareness of environmental protection, the development of biodegradable, green filter rod materials has become an urgent need in the industry.

[0003] Against this backdrop, paper filter rods produced using the airflow-laid dry-laid papermaking process demonstrate significant advantages. Compared to traditional wet-laid papermaking, the dry-laid process requires less water, eliminating wastewater disposal issues. Airflow-laid technology also allows for a three-dimensional distribution of fibers, creating a fluffier, more porous structure. This ensures the filter rod's air permeability while improving its efficiency in retaining harmful substances. More importantly, the dry-laid process is adaptable to a wide range of fiber raw materials and can easily incorporate various functional additives, opening up the possibility of developing multifunctional filter rods.

[0004] However, existing paper filter rods still have significant technical flaws: First, the active ingredients are unevenly distributed, and the functional materials added by the traditional dry process are prone to agglomeration. Second, although paper filter rods are inherently environmentally friendly, most of the additives or functional materials added to meet specific performance requirements are difficult to degrade. Third, there is a lack of systematic functional design, especially after the addition of natural functional materials, bacteria are prone to multiply, resulting in a shortened shelf life. These problems have seriously restricted the performance improvement and market application of paper filter rods.

[0005] The prior art provides a double-layer composite reconstituted tobacco paper filter rod and a preparation method thereof, comprising the following steps: composite embossing a reconstituted tobacco leaf roll and a forming paper coating roll, and rolling the roll using a filter rod forming machine to obtain the double-layer composite reconstituted tobacco paper filter rod. Summary of the Invention

[0006] In view of this, the purpose of this application is to provide a better degradable filter rod. To this end, this application provides the following technical solutions:

[0007] A double-layer composite filter rod comprises a porous adsorption layer and an antibacterial functional layer; the porous adsorption layer comprises a coniferous wood pulp fiber web and also comprises adsorbent particles dispersed in the coniferous wood pulp fiber web; the antibacterial functional layer comprises a nanofiber membrane and also comprises lignin sulfonate dispersed in the nanofiber membrane; the porous adsorption layer and the antibacterial functional layer are sequentially stacked, formed and cut to form a double-layer composite filter rod.

[0008] Furthermore, the adsorbent particles include activated carbon particles.

[0009] Furthermore, the D50 particle size of the activated carbon particles is 50 μm to 100 μm.

[0010] Furthermore, the activated carbon particles account for 20 wt% to 22 wt%, 22 wt% to 25 wt% or 25 wt% to 30 wt% of the porous adsorption layer.

[0011] Furthermore, the suction resistance of the double-layer composite filter rod is 280 mmH2O to 300 mmH2O, 300 mmH2O to 310 mmH2O, or 310 mmH2O to 330 mmH2O.

[0012] Furthermore, the activated carbon is lignin-based activated carbon.

[0013] Furthermore, the preparation method of lignin-based activated carbon is as follows: phosphoric acid and industrial lignin are uniformly mixed in a mass ratio of phosphoric acid: industrial lignin of (0.5-1.0):1.0, (1.0-2.0):1.0 or (2.0-2.5):1.0, and then carbonized and activated in a tubular furnace to obtain the obtained activated carbon.

[0014] Furthermore, the protective gas for carbonization activation in the tubular furnace is nitrogen.

[0015] Furthermore, the carbonization activation temperature of the tubular furnace carbonization activation is 400°C to 500°C, 500°C to 700°C or 700°C to 800°C.

[0016] Furthermore, the preparation method of the porous adsorption layer comprises the following steps:

[0017] Step S11, after the softwood pulp fibers are subjected to napping treatment, the adsorbent particles are added, and a dispersant is added to prevent the adsorbent particles from agglomerating to obtain mixed fibers;

[0018] Step S12: feeding the mixed fibers into an air-laid machine to form a first fiber web under the action of a high-speed airflow;

[0019] Step S13: shaping the first fiber web by a hot pressing roller to obtain the porous adsorption layer.

[0020] Furthermore, in step S11, the dispersant is sodium carboxymethyl cellulose, and the added amount of sodium carboxymethyl cellulose is 0.5wt% to 0.6wt%, 0.6wt% to 0.8wt% or 0.8wt% to 1.0wt%.

[0021] Furthermore, in step S12, the weight of the first fiber web is 40 g / m 2 ~45g / m 2 , 45g / m 2 ~55g / m 2 or 55g / m 2 ~60g / m 2 , the porosity of the first fiber web is ≥70%, ≥75% or ≥80%;

[0022] Furthermore, in step S13 , the shaping temperature of the hot pressing roller is 120° C. to 130° C., 130° C. to 140° C., or 140° C. to 150° C., and the shaping pressure is 0.5 MPa to 0.6 MPa, 0.6 MPa to 0.8 MPa, or 0.8 MPa to 1.0 MPa.

[0023] Furthermore, the preparation method of the nanofiber membrane comprises the following steps:

[0024] Step S21, dissolving polylactic acid or polyvinyl alcohol in hexafluoroisopropanol to prepare a polymer solution with a concentration of 8 wt% to 9 wt%, 9 wt% to 10 wt%, or 10 wt% to 12 wt%;

[0025] Step S22, adding 5 wt% to 6 wt%, 6 wt% to 8 wt% or 8 wt% to 10 wt% of lignin sulfonate to the polymer solution, and ultrasonically dispersing for at least 20 min, 25 min or 30 min to obtain a spinning solution;

[0026] Step S23: using a high-voltage electrospinning device to spin the spinning solution into a nanofiber membrane to form a spinning membrane;

[0027] Step S24: placing the spinning membrane in a vacuum drying oven to remove residual hexafluoroisopropanol.

[0028] Furthermore, when spinning the spinning solution into the nanofiber membrane in step S23, the fiber diameter is controlled to be 0.5 μm to 1.0 μm, 1.0 μm to 1.5 μm, or 1.5 μm to 2 μm.

[0029] Furthermore, in step S23, the voltage of the high-voltage electrospinning equipment is 15kV to 17kV, 17kV to 19kV or 19kV to 20kV, and the receiving distance is no more than 10cm, 15cm or 20cm.

[0030] Furthermore, the lamination step includes spraying PVAc adhesive on the interface between the porous adsorption layer and the antibacterial functional layer, with a spray coating amount of 3.0 g / m 2 ~4.0g / m 2 , 4.0g / m 2 ~4.5g / m 2 , or 4.5g / m 2 ~5.0g / m 2 .

[0031] A second aspect of the present invention provides an aerosol generating article comprising a double-layer composite filter rod.

[0032] The beneficial effects of the present invention compared to the prior art are:

[0033] 1. This invention achieves a breakthrough in functional diversification. While conventional reconstituted tobacco filter rods achieve structural improvements solely through physical compounding, this invention innovatively integrates an activated carbon adsorption layer (dry-laid papermaking) and a nanofiber antibacterial layer (electrospinning) into the substrate, enabling a single filter rod to simultaneously possess both chemical adsorption and biological antibacterial functions, achieving a qualitative leap in functionality.

[0034] 2. Traditional cigarette filter rods generally use cellulose acetate materials. Although they have good filtering performance, they have the problem of non-degradable environmental pollution. In order to overcome this limitation, the industry has turned to the research and development of paper filter rods. However, ordinary paper filter rods rely only on physical fiber interception and have a single function, which cannot meet the diversified needs of modern consumers for health protection. In-depth analysis found that the root cause of this technical bottleneck is that the traditional papermaking process is difficult to achieve uniform dispersion and stable combination of functional additives. Although the dry papermaking process provides the possibility of adding functional materials, it faces new challenges in actual application, such as uneven distribution of additives and poor functional synergy. The present invention provides a degradable cigarette paper filter rod with adsorption and antibacterial functions. It is beneficial to provide a new functionalization path for existing paper filter rods, especially paper filter rods with added natural functional ingredients. The inventors of the present invention found that paper filter rods that do not contain cellulose acetate at all have poor antibacterial properties, and the antibacterial properties are even worse after adding natural functional materials. The inventors further optimized the fiber ratio and dispersion process for dry-process papermaking to ensure uniform distribution of additives such as activated carbon. They also innovatively adopted a two-layer composite structure, using electrospinning technology to create an independent antibacterial functional layer. This technical solution not only retains the environmentally friendly properties of paper materials but also, through process and structural innovations, systematically addresses the technical challenges of transitioning from basic filtration to multifunctional integration, achieving a qualitative leap in filter rod performance.

[0035] 3. This invention innovatively proposes a multifunctional composite paper filter rod solution based on an airflow-formed dry-laid papermaking process. By optimizing the fiber ratio and process parameters, combined with an electrospinning functional layer, this technology achieves a synergistic improvement in the filter rod's adsorption and antibacterial properties while maintaining the environmental advantages of dry-laid papermaking. This technology not only addresses the environmental pollution issues of traditional cellulose acetate filter rods but also overcomes the functional limitations of existing paper filter rods, providing the industry with a truly green and efficient alternative. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above content of this application and the following specific embodiments will be better understood when read in conjunction with the accompanying drawings. It should be noted that the accompanying drawings are only examples of the technical solutions claimed.

[0037] Figure 1 It is a three-dimensional schematic diagram of a double-layer filter rod;

[0038] Figure 2 It is a three-dimensional schematic diagram of a cigarette containing a double-layer filter rod;

[0039] Figure 3 This is a schematic diagram of the molding process of a cigarette containing a double-layer filter rod from material to finished product;

[0040] Figure 4 This is a process flow chart for manufacturing double-layer filter rods.

[0041] The description of the accompanying drawings is as follows:

[0042] 100: Double-layer composite filter rod;

[0043] 110: porous adsorption layer;

[0044] 120: antibacterial functional layer;

[0045] 130: composite layer;

[0046] 1: filter rod segment;

[0047] 2: Tobacco segments. DETAILED DESCRIPTION

[0048] The detailed features and advantages of the present application are described in detail below in the specific implementation methods, and the content is sufficient to enable any technical personnel in this field to understand the technical content of the present application and implement it accordingly. Based on the description, claims and drawings disclosed in this specification, technical personnel in this field can easily understand the relevant purposes and advantages of the present application.

[0049] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0050] refer to Figures 1 to 4 The present invention provides a double-layer composite filter rod 100, comprising a porous adsorption layer 110 and an antibacterial functional layer 120; the porous adsorption layer comprises a coniferous wood pulp fiber web, and also comprises adsorbent particles dispersed in the coniferous wood pulp fiber web; the antibacterial functional layer comprises a nanofiber membrane, and also comprises lignin sulfonate dispersed in the nanofiber membrane; the porous adsorption layer 110 and the antibacterial functional layer 120 are sequentially stacked, formed and cut to form the double-layer composite filter rod 100.

[0051] Specifically, the adsorbent particles include activated carbon particles. The D50 particle size of the activated carbon particles is 50 μm to 100 μm. The activated carbon particles account for 20 wt% to 22 wt%, 22 wt% to 25 wt% or 25 wt% to 30 wt% of the porous adsorption layer.

[0052] Specifically, the suction resistance of the double-layer composite filter rod is 280 mmH2O to 300 mmH2O, 300 mmH2O to 310 mmH2O, or 310 mmH2O to 330 mmH2O.

[0053] Specifically, the activated carbon is lignin-based activated carbon.

[0054] More specifically, the preparation method of lignin-based activated carbon is as follows: phosphoric acid and industrial lignin are mixed uniformly at a mass ratio of phosphoric acid: industrial lignin of (0.5-1.0):1.0, (1.0-2.0):1.0 or (2.0-2.5):1.0, and then carbonized and activated in a tubular furnace; the protective gas for carbonization and activation in the tubular furnace is nitrogen; the carbonization and activation temperature of the tubular furnace carbonization and activation is 400°C-500°C, 500°C-700°C or 700°C-800°C.

[0055] Advantageously, lignin-based activated carbon can be prepared based on industrial lignin, which is a common by-product of the papermaking process. In the tobacco field, papermaking processes are used in the preparation of reconstituted tobacco leaf sheets and paper filter rods. Making full use of industrial lignin is conducive to reducing waste utilization and meeting the requirements of green development.

[0056] Specifically, the method for preparing the porous adsorption layer includes the following steps:

[0057] Step S11, after the softwood pulp fibers are subjected to napping treatment, adsorbent particles are added, and a dispersant is added to prevent the adsorbent particles from agglomerating to obtain mixed fibers;

[0058] Step S12: feeding the mixed fibers into an air-laid machine to form a first fiber web under the action of a high-speed airflow;

[0059] Step S13: shaping the first fiber web by a hot pressing roller to obtain a porous adsorption layer.

[0060] More specifically, the dispersant in step S11 is sodium carboxymethyl cellulose, and the amount of sodium carboxymethyl cellulose added is 0.5wt% to 0.6wt%, 0.6wt% to 0.8wt% or 0.8wt% to 1.0wt%; the weight of the first fiber web in step S12 is 40g / m 2 ~45g / m 2 , 45g / m 2 ~55g / m 2 or 55g / m 2 ~60g / m 2 , the porosity of the first fiber web is ≥70%, ≥75% or ≥80%; the shaping temperature of the hot pressing roller in step S13 is 120°C~130°C, 130°C~140°C or 140°C~150°C, and the shaping pressure is 0.5MPa~0.6MPa, 0.6MPa~0.8MPa or 0.8MPa~1.0MPa.

[0061] Specifically, the method for preparing the nanofiber membrane includes the following steps:

[0062] Step S21, dissolving polylactic acid or polyvinyl alcohol in hexafluoroisopropanol to prepare a polymer solution with a concentration of 8 wt% to 9 wt%, 9 wt% to 10 wt%, or 10 wt% to 12 wt%;

[0063] Step S22, adding 5 wt% to 6 wt%, 6 wt% to 8 wt% or 8 wt% to 10 wt% of lignin sulfonate to the polymer solution, and ultrasonically dispersing for at least 20 min, 25 min or 30 min to obtain a spinning solution;

[0064] Step S23: using a high-voltage electrospinning device to spin the spinning solution into a nanofiber membrane to form a spinning membrane;

[0065] Step S24: placing the spinning membrane in a vacuum drying oven to remove residual hexafluoroisopropanol.

[0066] Specifically, when the spinning solution is spun into a nanofiber membrane in step S23, the fiber diameter is controlled to be 0.5μm~1.0μm, 1.0μm~1.5μm or 1.5μm~2μm; the voltage of the high-voltage electrospinning equipment is 15kV~17kV, 17kV~19kV or 19kV~20kV, and the receiving distance is not greater than 10cm, 15cm or 20cm.

[0067] Specifically, the lamination step includes spraying PVAc adhesive on the interface between the porous adsorption layer and the antibacterial functional layer, with a spray coating amount of 3.0 g / m 2 ~4.0g / m 2 , 4.0g / m 2 ~4.5g / m2 , or 4.5g / m 2 ~5.0g / m 2 .

[0068] The present invention also provides an aerosol generating product, comprising a double-layer composite filter stick.

[0069] In the following examples, the names of specific manufacturing equipment or experimental instruments and the manufacturers of the equipment are shown in Table 1:

[0070] Table 1 Name of manufacturing equipment or experimental equipment and purchasing manufacturer

[0071]

[0072] In the following examples, the specific raw material names and purchasing manufacturers are shown in Table 2:

[0073] Table 2 Raw material names and purchasing manufacturers

[0074]

[0075]

[0076] Example 1

[0077] (1) Porous adsorption layer

[0078] After softwood pulp fibers (cotton pulp fibers) were fluffed, activated carbon particles (D50 particle size 50 μm, addition level 30 wt%) were added. Sodium carboxymethyl cellulose (CMC, 1.0 wt%) was added as a dispersant to prevent agglomeration of the activated carbon. Lignin-based activated carbon was prepared by mixing industrial lignin with 85% phosphoric acid at a mass ratio of 0.5:1 (phosphoric acid: industrial lignin). Nitrogen was used as the shielding gas for carbonization and activation in a tubular furnace at a flow rate of 500 ml / min and an activation temperature of 800°C.

[0079] The mixed fibers are fed into the air-laid machine to form a uniform fiber web under the action of high-speed airflow. Control the fiber web weight (60g / m 2 ) to ensure a porosity of ≥80%. Use a hot pressing roller (150°C, pressure 1MPa) to shape the fiber web to form a porous adsorption layer.

[0080] (2) Preparation of antibacterial functional layer (electrospinning process)

[0081] Polylactic acid (PLA) was dissolved in hexafluoroisopropanol (HFIP) to prepare an 8% polymer solution. Lignin sulfonate (5%) was added and ultrasonically dispersed for 40 minutes to ensure uniform mixing. The spinning solution was spun into a nanofiber membrane using a high-voltage electrospinning device (voltage 20 kV, receiving distance 15 cm). The fiber diameter (1 μm) was controlled to form an antibacterial network with a high specific surface area. The spun membrane was placed in a vacuum drying oven at 60°C for 24 hours to thoroughly remove any residual solvent.

[0082] (3) Assembly of double-layer composite filter rod

[0083] The activated carbon adsorption layer and the antibacterial functional layer were superimposed, and the interface was sprayed with food-grade PVAc adhesive (coating amount 5g / m 2 The composite material is then wrapped with mold paper and fed into a filter rod forming machine for rolling and cutting into standard lengths (e.g., 7–8 mm). The final product has a draw resistance of 280–330 mmH2O.

[0084] Example 2

[0085] (1) Porous adsorption layer

[0086] After fluffing softwood pulp fibers (cotton and hemp), activated carbon particles (D50 particle size 100 μm, 20 wt%) were added. Sodium carboxymethyl cellulose (CMC, 1.0 wt%) was added as a dispersant to prevent agglomeration of the activated carbon. Lignin-based activated carbon was prepared by mixing industrial lignin with 85% phosphoric acid at a 1:1 ratio (phosphoric acid: industrial lignin, by weight). Nitrogen was used as the shielding gas for carbonization and activation in a tubular furnace at a flow rate of 500 ml / min and an activation temperature of 400°C.

[0087] The mixed fibers are fed into the air-laid machine to form a uniform fiber web under the action of high-speed airflow. Control the fiber web weight (40g / m 2 ) to ensure a porosity of ≥80%. Use a hot pressing roller (120°C, pressure 0.5MPa) to shape the fiber web to form a porous adsorption layer.

[0088] (2) Preparation of antibacterial functional layer (electrospinning process)

[0089] Polylactic acid (PLA) was dissolved in hexafluoroisopropanol (HFIP) to prepare a 10% polymer solution. Lignin sulfonate (7 wt%) was added and ultrasonically dispersed for 30 minutes to ensure uniform mixing. The spinning solution was spun into a nanofiber membrane using a high-voltage electrospinning device (voltage 15 kV, receiving distance 15 cm). The fiber diameter (2 μm) was controlled to form an antibacterial network with a high specific surface area. The spun membrane was placed in a 50°C vacuum drying oven for 12 hours to thoroughly remove any residual solvent.

[0090] (3) Assembly of double-layer composite filter rod

[0091] The activated carbon adsorption layer and the antibacterial functional layer were superimposed, and the interface was sprayed with food-grade PVAc adhesive (coating amount 5g / m 2 The composite material is then wrapped with mold paper and fed into a filter rod forming machine for rolling and cutting into standard lengths (7 mm). The final product has a draw resistance of 280-330 mmH2O.

[0092] Example 3

[0093] (1) Porous adsorption layer

[0094] After fluffing softwood pulp fibers (cotton and hemp), activated carbon particles (D50 particle size 150 μm, 25 wt%) were added. Sodium carboxymethyl cellulose (CMC, 1.0 wt%) was added as a dispersant to prevent agglomeration of the activated carbon. Lignin-based activated carbon was prepared by mixing industrial lignin with 85% phosphoric acid at a ratio of 2.5:1 (phosphoric acid: industrial lignin, by mass). Nitrogen was used as the shielding gas for carbonization and activation in a tubular furnace at a temperature of 600°C at a flow rate of 500 ml / min.

[0095] The mixed fibers are fed into the air-laid machine to form a uniform fiber web under the action of high-speed airflow. Control the fiber web weight (50g / m 2 ) to ensure a porosity of ≥80%. Use a hot pressing roller (130°C, pressure 0.8MPa) to shape the fiber web to form a porous adsorption layer.

[0096] (2) Preparation of antibacterial functional layer (electrospinning process)

[0097] Polyvinyl alcohol (PVA) was dissolved in hexafluoroisopropanol (HFIP) to prepare a 12% polymer solution. Lignin sulfonate (10%) was added and ultrasonically dispersed for 30 minutes to ensure uniform mixing. The spinning solution was spun into a nanofiber membrane using a high-voltage electrospinning device (voltage 20kV, receiving distance 15cm). The fiber diameter (2μm) was controlled to form an antibacterial network with a high specific surface area. The spun membrane was placed in a vacuum drying oven at 60°C for 24 hours to thoroughly remove any residual solvent.

[0098] (3) Assembly of double-layer composite filter rod

[0099] The activated carbon adsorption layer and the antibacterial functional layer were superimposed, and the interface was sprayed with food-grade PVAc adhesive (coating amount 5g / m 2The composite material is then wrapped with mold paper and fed into a filter rod forming machine for rolling and cutting into standard lengths (e.g., 7–8 mm). The final product has a draw resistance of 280–330 mmH2O.

[0100] Example 4

[0101] (1) Porous adsorption layer

[0102] After softwood pulp fibers (cotton pulp fibers) were fluffed, activated carbon particles (D50 particle size 50 μm, addition level 30 wt%) were added. Sodium carboxymethyl cellulose (CMC, 1.0 wt%) was added as a dispersant to prevent agglomeration of the activated carbon. Lignin-based activated carbon was prepared by mixing industrial lignin with 85% phosphoric acid at a mass ratio of 0.5:1 (phosphoric acid: industrial lignin). Nitrogen was used as the shielding gas for carbonization and activation in a tubular furnace at a flow rate of 500 ml / min and an activation temperature of 800°C.

[0103] The mixed fibers are fed into the air-laid machine to form a uniform fiber web under the action of high-speed airflow. Control the fiber web weight (60g / m 2 ) to ensure a porosity of ≥80%. Use a hot pressing roller (150°C, pressure 1MPa) to shape the fiber web to form a porous adsorption layer.

[0104] (2) Preparation of antibacterial functional layer (electrospinning process)

[0105] Polylactic acid (PLA) was dissolved in hexafluoroisopropanol (HFIP) to prepare an 8% polymer solution. Lignin sulfonate (5%) and dye (1%) were added, and ultrasonic dispersion was performed for 40 minutes to ensure uniform mixing. The spinning solution was spun into a nanofiber membrane using a high-voltage electrospinning device (voltage 20kV, receiving distance 15cm). The fiber diameter (1μm) was controlled to form an antibacterial network with a high specific surface area. The spun membrane was placed in a vacuum drying oven at 60°C for 24 hours to thoroughly remove any residual solvent.

[0106] (3) Assembly of double-layer composite filter rod

[0107] The activated carbon adsorption layer and the antibacterial functional layer were superimposed, and the interface was sprayed with food-grade PVAc adhesive (coating amount 5g / m 2 The composite material is then wrapped with mold paper and fed into a filter rod forming machine for rolling and cutting into standard lengths (e.g., 7–8 mm). The final product has a draw resistance of 280–330 mmH2O.

[0108] Example 5

[0109] This embodiment provides an aerosol-generating product, specifically a cigarette, comprising a filter rod segment 1 and a tobacco segment 2, wherein the filter rod segment 1 and the tobacco segment 2 are assembled by a method well known to those skilled in the tobacco field.

[0110] The filter rod segment 1 includes a double-layer composite filter rod 100 and tipping paper wrapped around the outer side of the double-layer composite filter rod 100 .

[0111] It will be appreciated that in other embodiments, the aerosol-generating article is a smoking article comprising an aerosol-forming substrate which, upon heating, generates an aerosol which is directly inhalable into the lungs of a user through the user's mouth.

[0112] Preferably, the aerosol-forming substrate is a solid aerosol-forming substrate.The aerosol-forming substrate may comprise both solid and liquid components.

[0113] Preferably, the aerosol-forming substrate comprises nicotine.In some preferred embodiments, the aerosol-forming substrate comprises tobacco.

[0114] For example, the aerosol-forming material may be formed from a sheet of homogenised tobacco.

[0115] Alternatively or additionally, the aerosol-forming substrate may comprise a tobacco-free aerosol-forming material.For example, the aerosol-forming material may be a sheet comprising nicotine salt and an aerosol-former.

[0116] If the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may comprise one or more of a powder, granules, pellets, shreds, strips, rods or sheets containing one or more of herb leaves, tobacco leaves, tobacco ribs, flat tobacco and homogenised tobacco.

[0117] Optionally, the solid aerosol-forming substrate may comprise tobacco volatile aroma compounds or non-tobacco volatile aroma compounds that are released upon heating the solid aerosol-forming substrate. The solid aerosol-forming substrate may also comprise one or more capsules comprising, for example, additional tobacco volatile aroma compounds or non-tobacco volatile aroma compounds, and such capsules may melt during heating of the solid aerosol-forming substrate.

[0118] Optionally, the solid aerosol-forming substrate may be disposed on or embedded in a thermally stable carrier. The carrier may be in the form of a powder, granules, pellets, chips, strips, bars, or sheets. The solid aerosol-forming substrate may be disposed on the surface of the carrier in the form of, for example, a sheet, foam, gel, or slurry. The solid aerosol-forming substrate may be placed over the entire surface of the carrier, or alternatively, may be arranged in a pattern to provide uneven flavor delivery during use.

[0119] Comparative Example 1

[0120] A sheath-core tobacco tow comprises a sheath layer and a core layer. The sheath layer is prepared from the following raw materials in parts by mass: 90 parts polylactic acid resin; 0.2 parts fumed hydrophobic silica; and 1.5 parts powdered poly(p-phenylene terephthalamide) (800-1000 mesh). The core layer is prepared from the following raw materials in parts by mass: 83 parts polylactic acid resin; 3 parts lignin; 1 part powdered poly(p-phenylene terephthalamide) (800-1000 mesh); and 0.26 parts fumed hydrophobic silica. The mass ratio of the sheath layer to the core layer is 1:15. The lignin in the core layer requires pretreatment. The pretreatment process involves washing the industrial lignin with acetone, washing with water, and drying it to obtain the pretreated lignin. The lignin is dried by sun exposure and air drying. The preparation method of the above-mentioned sheath-core type tobacco tow comprises the following steps: (1) drying the sheath layer raw material and the core layer raw material separately to make the moisture content less than 150 mg / kg; (2) feeding the sheath layer raw material into the first spinning system according to the mass ratio, melting it at a temperature between 240 and 270°C and quantitatively inputting it into the composite spinning component; feeding the sheath layer raw material into the second spinning system according to the mass ratio, melting it at a temperature between 200 and 240°C and quantitatively inputting it into the composite spinning component; the two molten fluids flow in independent pipes respectively, and mix to form sheath-core type composite fibers when exiting the spinneret; (3) cooling, drawing, curling and drying the composite fibers in step (2) to obtain the sheath-core type tobacco tow.

[0121] The skin layer and core layer raw materials need to be completely mixed before being fed into the spinning system. In step (3), the drawing temperature is between 75 and 85°C, and the curling temperature is between 81 and 90°C.

[0122] Comparative Example 2

[0123] Diatomaceous earth and medical stone with a particle size distribution of 1μm to 10μm were selected as adsorbent filling materials. 0.2% of the adsorbent filling materials by weight of diacetate fiber was added to the spinning slurry of diacetate fiber and the mixture was fully mixed and dispersed evenly. Filaments were spun by dry spinning process. The filaments were then milled to obtain diacetate fiber pulp. The diacetate fiber pulp was mixed with the milled wood pulp in a weight ratio of 1:0.05. Paper was made by dry papermaking process to obtain a paper with a basis weight of 12g / m 2 The prepared paper is embossed and cut into 30cm narrow widths. The paper is then made into filter rods using a filter rod forming machine. The paper is then composited with a diacetate filter rod to produce a binary composite filter rod with a composite ratio of 10mm:15mm.

[0124] Comparative Example 3

[0125] A sheath-core tobacco tow comprises a sheath layer and a core layer. The sheath layer is prepared from the following raw materials in parts by weight: 90 parts polylactic acid resin; 0.2 parts fumed hydrophobic silica; and 1.5 parts powdered poly(p-phenylene terephthalamide) (800-1000 mesh). The core layer is prepared from the following raw materials in parts by weight: 83 parts polylactic acid resin; 3 parts lignin; 1 part powdered poly(p-phenylene terephthalamide) (800-1000 mesh); 0.26 parts fumed hydrophobic silica; and 1 part dye. The mass ratio of the sheath layer to the core layer is 1:15. The lignin in the core layer requires pretreatment. The pretreatment process involves washing the industrial lignin with acetone, washing with water, and drying it to obtain the pretreated lignin. The lignin is dried by sun exposure and air drying. The preparation method of the above-mentioned sheath-core type tobacco tow comprises the following steps: (1) drying the sheath layer raw material and the core layer raw material separately to make the moisture content less than 150 mg / kg; (2) feeding the sheath layer raw material into the first spinning system according to the mass ratio, melting it at a temperature between 240 and 270°C and quantitatively inputting it into the composite spinning component; feeding the sheath layer raw material into the second spinning system according to the mass ratio, melting it at a temperature between 200 and 240°C and quantitatively inputting it into the composite spinning component; the two molten fluids flow in independent pipes respectively, and mix to form sheath-core type composite fibers when exiting the spinneret; (3) cooling, drawing, curling and drying the composite fibers in step (2) to obtain the sheath-core type tobacco tow.

[0126] The skin layer and core layer raw materials need to be completely mixed before being fed into the spinning system. In step (3), the drawing temperature is between 75 and 85°C, and the curling temperature is between 81 and 90°C.

[0127] Hardness and absorption resistance test

[0128] The test methods for indicators such as hardness and draw resistance of cigarette filter rods refer to GBT 22838-2024 "Determination of physical properties of cigarettes and filter rods".

[0129] Antibacterial test

[0130] ① Prepare LB (beef extract peptone) solution

[0131] Tryptone 10g / L; NaCl 10g / L; Yeast 5g / L; pH = 7.0-7.4

[0132] ②Sample preparation

[0133] The samples in Examples and Comparative Examples were prepared into circular samples with a diameter of 6 mm.

[0134] ③Sterilization operation

[0135] Wrap the culture dish, spreader, deionized water (into a conical flask), LB solution, and LB solution with 2% agar (20 g / L) (100 mL per conical flask) in newspaper, place them in a sterilizer, and sterilize at 121°C for 45 minutes.

[0136] ④ Activation of E. coli

[0137] Take 100 μL of the frozen E. coli and place it in 5 mL of LB culture medium. Place the culture solution on a shaker at 37°C and 200 r / min. Take it out after 12 hours. Then take 100 μL of the above culture solution and place it in 5 mL of LB culture medium. Place the culture solution on a shaker at 37°C and 200 r / min. Take it out after 2-3 hours.

[0138] ⑤Measure OD value

[0139] Take 1 mL of the cultured bacterial solution and centrifuge it at 8000 rpm for 5 minutes. Pour off the supernatant and add 3 mL of water. Stir well and measure the absorbance of the bacterial solution at 600 nm in a UV spectrophotometer. Then dilute the bacterial solution (with sterile water) to 5-5*106 cfu / mL (1OD = 1*109 cfu / mL).

[0140] ⑥Experimental steps

[0141] Place the disinfected instruments and samples on a sterile workbench and irradiate with UV light for 30 minutes. Pour approximately 30 mL of LB solution into each Petri dish and let it sit for 15 minutes until the agar solidifies. Place 200 μL of the diluted bacterial solution into the Petri dish. Rotate the dish to evenly distribute the solution on the surface. Let it sit for approximately 15 minutes. Place the samples on the surface of the culture medium, three per dish. Cover the Petri dish, seal it with parafilm, and place it in a 37.5°C incubator. After 7 hours, observe and measure the diameter of the inhibition zone around the sample and record it as shown in Table 3.

[0142] Biodegradation rate test

[0143] 1g of each Example and Comparative Example sample was buried in natural outdoor soil at a depth of 6cm to examine the biodegradability of the five samples in the soil. The samples were then buried for 30 days. The weight of the samples before and after degradation was recorded, and the biodegradation rates were calculated as shown in Table 3.

[0144] Table 3. Performance tests of examples and comparative examples

[0145]

[0146] In summary, the present application provides a cigarette filter rod with adsorption and antibacterial functions. It is beneficial to provide a new functionalization path for existing paper filter rods, especially paper filter rods with added natural functional ingredients. Taking the colored filter rod as an example, it has chemical adsorption mainly to partially filter out harmful substances such as tar and nicotine, reduce the irritation of smoke, and improve the taste; the colored filter rod may become a breeding ground for microorganisms due to the dye (lemon yellow, bright blue, fruit green) ingredients and humid environment. On the other hand, to prevent bacteria from decomposing dyes or adsorbed organic matter, and to avoid fading and odor, bio-antibacterial properties are required. It can improve the safety, durability and user experience of the product, and meet the dual needs of consumers for health and fashion.

[0147] Similarly, it should be pointed out that although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should realize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the invention. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A double-layer composite filter rod, characterized in that: It includes a porous adsorption layer and an antibacterial functional layer; The porous adsorption layer includes a softwood pulp fiber web and adsorbent particles dispersed in the softwood pulp fiber web; The antibacterial functional layer includes a nanofiber membrane and lignin sulfonate dispersed in the nanofiber membrane; The porous adsorption layer and the antibacterial functional layer are sequentially stacked, formed and cut to form the double-layer composite filter rod.

2. The double-layer composite filter rod according to claim 1, characterized in that: The adsorbent particles include activated carbon particles; The D50 particle size of the activated carbon particles is 50 μm to 100 μm; The activated carbon particles account for 20 wt% to 22 wt%, 22 wt% to 25 wt% or 25 wt% to 30 wt% of the porous adsorption layer.

3. The double-layer composite filter rod according to claim 1, characterized in that: The suction resistance of the double-layer composite filter rod is 280 mmH2O to 300 mmH2O, 300 mmH2O to 310 mmH2O or 310 mmH2O to 330 mmH2O.

4. The double-layer composite filter rod according to claim 2, characterized in that: The activated carbon is lignin-based activated carbon; The lignin-based activated carbon is prepared by mixing phosphoric acid and industrial lignin at a mass ratio of phosphoric acid to industrial lignin of (0.5-1.0):1.0, (1.0-2.0):1.0 or (2.0-2.5):1.0, uniformly mixing the mixture, and then carbonizing and activating the mixture in a tubular furnace. The protective gas for carbonization activation in the tubular furnace is nitrogen; The carbonization activation temperature of the tubular furnace carbonization activation is 400°C to 500°C, 500°C to 700°C or 700°C to 800°C.

5. The double-layer composite filter rod according to claim 1, characterized in that: The method for preparing the porous adsorption layer comprises the following steps: Step S11, after the softwood pulp fibers are subjected to napping treatment, the adsorbent particles are added, and a dispersant is added to prevent the adsorbent particles from agglomerating to obtain mixed fibers; Step S12: feeding the mixed fibers into an air-laid machine to form a first fiber web under the action of a high-speed airflow; Step S13: shaping the first fiber web by a hot pressing roller to obtain the porous adsorption layer.

6. The double-layer composite filter rod according to claim 5, characterized in that: In step S11, the dispersant is sodium carboxymethyl cellulose, and the addition amount of the sodium carboxymethyl cellulose is 0.5wt% to 0.6wt%, 0.6wt% to 0.8wt% or 0.8wt% to 1.0wt%; The weight of the first fiber web in step S12 is 40 g / m 2 ~45g / m 2 , 45g / m 2 ~55g / m 2 or 55g / m 2 ~60g / m 2 , the porosity of the first fiber web is ≥70%, ≥75% or ≥80%; The shaping temperature of the hot pressing roller in step S13 is 120° C. to 130° C., 130° C. to 140° C., or 140° C. to 150° C., and the shaping pressure is 0.5 MPa to 0.6 MPa, 0.6 MPa to 0.8 MPa, or 0.8 MPa to 1.0 MPa.

7. The double-layer composite filter rod according to claim 1, characterized in that: The method for preparing the nanofiber membrane comprises the following steps: Step S21, dissolving polylactic acid or polyvinyl alcohol in hexafluoroisopropanol to prepare a polymer solution with a concentration of 8 wt% to 9 wt%, 9 wt% to 10 wt%, or 10 wt% to 12 wt%; Step S22, adding 5 wt% to 6 wt%, 6 wt% to 8 wt% or 8 wt% to 10 wt% of lignin sulfonate to the polymer solution, and ultrasonically dispersing for at least 20 min, 25 min or 30 min to obtain a spinning solution; Step S23: using a high-voltage electrospinning device to spin the spinning solution into a nanofiber membrane to form a spinning membrane; Step S24: placing the spinning membrane in a vacuum drying oven to remove the hexafluoroisopropanol residue.

8. The double-layer composite filter rod according to claim 7, characterized in that: When spinning the spinning solution into a nanofiber membrane in step S23, the diameter of the fiber is controlled to be 0.5 μm to 1.0 μm, 1.0 μm to 1.5 μm, or 1.5 μm to 2 μm; The voltage of the high-voltage electrospinning equipment in step S23 is 15kV to 17kV, 17kV to 19kV or 19kV to 20kV, and the receiving distance is no more than 10cm, 15cm or 20cm.

9. The double-layer composite filter rod according to claim 1, characterized in that: The lamination step includes spraying PVAc adhesive onto the interface between the porous adsorption layer and the antibacterial functional layer, with the spray coating amount being 3.0 g / m 2 ~4.0g / m 2 , 4.0g / m 2 ~4.5g / m 2 , or 4.5g / m 2 ~5.0g / m 2 .

10. An aerosol-generating article, characterized in that It comprises the double-layer composite filter rod according to any one of claims 1 to 9.

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