WO2025020078A1 - Lyocell fiber tow for heat-not-burn cigarette filter tip and preparation me thod, heat-not-burn cigarette and filter tip - Google Patents

Abstract

A lyocell fiber tow for a heat-not-burn cigarette filter tip and a preparation method therefor, a heat-not-burn cigarette and a filter tip. The denier per filament of the lyocell fiber tow is controlled in the range from 10.0 D to 30.0 D, the total denier of the tow is controlled in the range of 10000 D to 40000 D depending on the circumference of a filter stick, and the cross section of the lyocell fiber tow is elliptical or circular. Since the lower the denier per filament of the fiber tow, the higher the number of monofilaments, the greater the chance of collision between vape smoke and fibers during movement, and the higher the filtration efficiency of the filter tip, the lyocell fiber tow uses a high-denier-per-filament tow design to reduce the filtration effect thereof; when the denier per filament of the fiber tow remains unchanged, the filtration efficiency increases as the total denier of the fiber tow increases, therefore the lyocell fiber tow uses a low-total-denier design to increase the transmission efficiency for vape smoke; and since the cross section of the lyocell fiber tow is elliptical or circular, the specific surface area can be reduced, thereby achieving a high-permeability effect.

Description

Lyocell fiber tow for heat-not-burn cigarette filter and preparation method, heat-not-burn cigarette and filter Technical Field

The present application relates to the technical field of heat-not-burn cigarettes, and in particular to a lyocell fiber bundle for a heat-not-burn cigarette filter and a preparation method, a heat-not-burn cigarette and a filter.

Background Art

Heat-not-burn cigarettes are a new type of tobacco product. When inhaled, the heat-not-burn cigarette cartridge is heated but not burned. Aerosol is formed during heating, and smoke is produced by volatilization of atomizers, nicotine and flavoring substances. Heat-not-burn cigarettes are usually divided into a core segment, a support segment and a filter. Heat-not-burn cigarettes heat the cartridge with a heat source to produce smoke, and produce smoke for consumers to inhale in a non-combustion state. This unique method reduces the harmful smoke components produced by combustion and thermal decomposition in conventional cigarettes, and does not produce sidestream smoke. Since the core segment of heat-not-burn cigarettes can produce relatively less useful smoke, and the amount of smoke directly affects the consumer's smoking experience, the filter design of heat-not-burn cigarettes is mainly aimed at reducing smoke filtration, that is, preparing a highly transparent filter.

The low permeability is indirectly reflected in the draw resistance of the cigarette. The draw resistance of the entire heat-not-burn cigarette is composed of two parts: the wick draw resistance and the filter draw resistance. The wick draw resistance is determined by the arrangement order and filling amount of the tobacco shreds. Because of the need to consider the nicotine problem in the smoke, there is an extreme low value. Therefore, to achieve a high permeability of the smoke of heat-not-burn cigarettes, the key lies in the material selection and structural design of the filter.

At present, the materials used for heat-not-burn cigarette filters on the market mainly include acetate fiber, polylactic acid (PLA) and semi-crepe paper. Among them, polylactic acid is not heat-resistant, so it is more prone to thermal collapse when used as a filter material; acetate fiber will also face the risk of thermal collapse when used as a filter material under the condition of high permeability, and although acetate fiber is a biodegradable material, its degradation time is as long as 1 to 2 years, and it takes a long time to be completely biodegraded; semi-crepe paper filter rods are cheap in traditional cigarettes and have a stronger ability to remove tar and nicotine than acetate, but semi-crepe paper as a filter will face the contradiction between suction resistance and end face gaps. To achieve lower suction resistance, many gaps will be generated on the cross surface of the filter rod. At the same time, paper filters will also produce obvious unpleasant woody smell when heat-not-burn cigarettes are smoked.

Summary of the invention

The purpose of the present application is to provide a lyocell fiber tow for a heat-not-burn cigarette filter and a preparation method, a heat-not-burn cigarette and a filter, so as to solve the problems existing in the materials used in the above-mentioned existing heat-not-burn cigarette filters.

To achieve the above objectives, this application adopts the following technical solutions:

The present application first provides a lyocell fiber tow for a heat-not-burn cigarette filter, wherein the single denier of the lyocell fiber tow is controlled within the range of 10.0D-30.0D, and the total denier of the lyocell fiber tow is controlled within the range of 10000D-40000D according to the circumferential size required by the filter rod, and the cross-section of the lyocell fiber tow is elliptical or circular.

Preferably, the eccentricity e of the ellipse is in the range of 0<e<1.

The present application also provides a method for preparing a lyocell fiber tow for a heat-not-burn cigarette filter, comprising:

The aqueous solution of N-methylmorpholine-N-oxide is mixed with the natural fiber slurry and put into a twin-screw extruder to prepare a lyocell spinning solution;

The lyocell spinning solution is filtered and then wet-spinned by a spinneret with multiple holes, the lyocell spinning solution is kept at a spinning temperature of 100° C. to 110° C. at the spinning nozzle of the spinneret, and the discharge amount and spinning rate of the lyocell spinning solution are adjusted so that the single filament fineness of the final lyocell fiber is within a range of 10.0 denier to 30.0 denier;

The filamentary spinning solution discharged from the spinning nozzle is cooled and solidified to obtain the lyocell fiber precursor;

The lyocell fiber raw yarn is subjected to water washing, oiling and drying treatments;

The treated lyocell fiber raw yarn is curled to obtain the above-mentioned lyocell fiber bundle for heat-not-burn cigarette filter.

Preferably, the lyocell fiber tow has 15 to 30 crimps per inch.

Preferably, the cooling and solidification includes supplying the filamentous spinning solution to a coagulation liquid in a coagulation bath via an air gap zone.

Preferably, the temperature of the coagulation liquid is less than or equal to 30°C.

The present application also provides a heat-not-burn cigarette filter, which includes the above-mentioned lyocell fiber tow for heat-not-burn cigarette filter.

Preferably, the heat-not-burn cigarette filter is formed by rolling the above-mentioned lyocell fiber tow for the heat-not-burn cigarette filter and forming paper.

Preferably, the draw resistance of the heat-not-burn cigarette filter is in the range of 2 Pa/mm-20 Pa/mm.

The present application also provides a heat-not-burn cigarette, comprising the above-mentioned heat-not-burn cigarette filter.

Compared with the prior art, the beneficial effects of this application include:

The denier of the lyocell fiber tow for heat-not-burn cigarette filters provided in this application is controlled within the range of 10.0D-30.0D, and the total denier of the tow is controlled within the range of 10000D-40000D according to the required filter rod circumference size, and its cross-section is elliptical or circular. The lower the denier of the fiber tow, the more the number of filaments, and the smoke moves. The more chances of collision with the fiber, the higher the filter efficiency. Therefore, the lyocell fiber tow for the heat-not-burn cigarette filter of the present application adopts a high single denier tow design to increase the smoke penetration efficiency. When the single denier of the fiber tow remains unchanged, the filtration efficiency increases with the increase of the total denier of the fiber tow. Therefore, the lyocell fiber tow for the heat-not-burn cigarette filter of the present application adopts a low total denier design to reduce its filtration effect. In addition, the shape of the cross section of the fiber tow is different, and its specific surface area is different, which will also affect the filtration efficiency of the cigarette filter rod; the fiber tow with a special-shaped cross section has a large specific surface area, and the filtration efficiency of the filter rod after molding is also high, which to a certain extent leads to problems such as low smoke concentration and poor satisfaction in the heat-not-burn cigarette. Therefore, the lyocell fiber tow for the heat-not-burn cigarette filter of the present application adopts an elliptical or circular cross section, which can reduce the specific surface area, thereby achieving a high permeability effect. The elliptical or circular cross section of the tow can also achieve physical extinction, and the visual effect of the prepared filter is better. Lyocell fibers are more biodegradable than cellulose acetate tow, thereby alleviating the problem of litter caused by discarded cigarette butts.

The heat-not-burn cigarette filter prepared from the lyocell fiber bundle for the heat-not-burn cigarette filter of the present application has high permeability, low pressure drop, no thermal collapse, is completely biodegradable, and is environmentally friendly and pollution-free.

The heat-not-burn cigarette prepared by the heat-not-burn cigarette filter of the present application has a high smoke concentration and a good sense of satisfaction when smoking, and does not produce unpleasant feelings such as woody smell.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

FIG1 is a cross-sectional shape of a lyocell fiber tow of the present application;

Figure 2 is a physical picture of the acetate filter after suction;

Figure 3 is a physical picture of the Lyocell fiber filter after suction.

DETAILED DESCRIPTION

As used herein:

"Prepared from" is synonymous with "comprising." As used herein, the terms "comprising,""including,""having,""containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range.

In these examples, parts and percentages are by mass unless otherwise indicated.

"Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

"And/or" is used to indicate that one or both of the stated situations may occur, for example, A and/or B includes (A and B) and (A or B).

Lyocell fiber is made of wood and bamboo, which are inexhaustible in nature. The manufacturing process is environmentally friendly. It has the comfort of cotton, the strength of polyester, the luxurious beauty of wool fabrics, and the unique touch and soft drape of silk. It is very tough whether it is dry or wet. Therefore, Lyocell fiber is widely used in clothing. However, in the prior art, Lyocell fiber is rarely used in the field of cigarettes, and there is no application in the application of heat-not-burn cigarette filters.

The present application first provides a lyocell fiber tow for a heat-not-burn cigarette filter, wherein the single denier of the lyocell fiber tow is controlled within the range of 10.0D-30.0D, for example, it can be 10.0D-20.0D, or 20.0D-30.0D, or 15.0D-25.0D. According to the required circumferential size of the filter rod, the total denier of the lyocell fiber tow is controlled within the range of 10000D-40000D, for example, it can be 10000D-2000D, or 20000D-30000D, or 30000D-40000D. The cross-section of the lyocell fiber tow is elliptical or circular.

Among them, single denier refers to the thickness of a single fiber in a fiber bundle, which is affected by the fiber diameter. The number of fibers in a fiber bundle is affected by the twist of the fiber bundle. The mass (g) of a 9000m long fiber is called denier (D).

Among them, the lower the denier of the fiber bundle, the more the number of monofilaments, the more chances of smoke colliding with the fiber during movement, and the higher the filter filtration efficiency. Therefore, the lyocell fiber bundle used for the heat-not-burn cigarette filter of the present application adopts a high denier bundle design, and the denier is controlled within the range of 10.0D-30.0D, which reduces its filtering effect. The fineness of the lyocell monofilament is 10.0 denier to 30.0 denier. If the fineness of the monofilament is less than 10.0 denier, the suction resistance of the heat-not-burn cigarette filter is too high; on the other hand, if its fineness exceeds 30.0 denier, the suction resistance of the heat-not-burn cigarette filter is too low. Taking these characteristics into account, the fineness of the fiber varies depending on the type of cigarette. Within the above-mentioned fineness range, the fineness can be selectively applied according to the type of cigarette.

When the single denier of the fiber bundle remains unchanged, the filtration efficiency increases with the increase of the total denier of the fiber bundle. Therefore, the lyocell fiber bundle used for the heat-not-burn cigarette filter of the present application adopts a low total denier design, and the total denier is controlled within the range of 10000D-40000D, thereby reducing its filtration effect.

In addition, the shapes of the fiber bundle cross-sections are different, and their specific surface areas are different, which will also affect the filtration efficiency of the cigarette filter rod; the fiber bundle with an irregular cross-section has a large specific surface area, and the filtration efficiency of the filter rod after molding is also high, which to a certain extent leads to problems such as low smoke concentration and poor satisfaction in heat-not-burn cigarettes. Therefore, the lyocell fiber bundle used for the heat-not-burn cigarette filter of the present application adopts an elliptical or circular cross-section, which can reduce the specific surface area and thus achieve a high permeability effect.

Preferably, referring to FIG. 1 , the eccentricity e of the ellipse is in the range of 0<e<1, wherein when e is 0, the cross section is circular, and the ellipse may be an ellipse of any shape with the range of 0<e<1.

The elliptical or circular cross-sectional shape can not only reduce the specific surface area of the fiber bundle and achieve a high-transparency effect; but also the fiber bundle with an elliptical or circular cross-section will form a certain optical path difference due to the reflection and refraction of light inside the fiber. Therefore, for certain wavelengths of light, they will appear in the fiber bundle to form interference fringes, thereby achieving extinction, causing the incident light to be diffusely reflected in different directions, so that the gloss intensity of the fiber surface is reduced and the bundle looks comfortable.

In the prior art, titanium dioxide is usually added as a matting agent during the synthetic fiber process to soften its luster. However, the International Agency for Research on Cancer (IARC) has stated that inhaled titanium dioxide may be a carcinogenic factor. Due to its effects when ingested (or ingested) in the oral cavity, it is questionable whether titanium dioxide can be used as a food additive. Therefore, lyocell fiber tow used in heat-not-burn cigarette filters is not suitable for titanium dioxide matting.

The present application also provides a method for preparing a lyocell fiber tow for a heat-not-burn cigarette filter, comprising:

The N-methylmorpholine-N-oxide aqueous solution is mixed with the natural fiber slurry and put into a twin-screw extruder to make Lyocell. Spinning solution;

The lyocell spinning stock solution is filtered and then wet-spun by dry jet spinning using a spinneret with multiple holes, thereby obtaining the lyocell multifilament of the present application, wherein the lyocell spinning stock solution is kept at a spinning temperature of 100° C. to 110° C. at the spinning nozzle of the spinneret, and the discharge amount and spinning rate of the lyocell spinning stock solution are adjusted so that the single filament fineness of the final lyocell fiber is within a range of 10.0 denier to 30.0 denier;

The filamentary spinning solution discharged from the spinning nozzle is cooled and solidified to obtain the lyocell fiber precursor;

The lyocell fiber raw yarn is subjected to water washing, oiling and drying treatments;

The treated lyocell fiber raw yarn is curled to obtain the above-mentioned lyocell fiber bundle for heat-not-burn cigarette filter.

Preferably, the lyocell fiber tow has 15 to 30 crimps per inch, for example, 15, 15.5, 16, 16.5, 18, 18.5, 20, 20.5, 22, 22.5, 25, 25.5, 26, 26.5, 28, 28.5 or 30, or any value between 15 and 30. Preferably, it has 25 to 30 crimps per inch.

In order to satisfy the performance required for the heat-not-burn cigarette filter, the number of crimps per inch is considered important. If the number of crimps is less than 15/inch, it is not easy to open the tow during the manufacturing process of the heat-not-burn cigarette filter, resulting in processing problems; in addition, the performance required for the heat-not-burn cigarette filter, such as draw resistance, filter hardness, filter removal performance, etc., are not satisfactory. On the other hand, if the number of crimps exceeds 30/inch, uneven extrusion occurs in the stuffing box and the tow cannot be effectively passed, making it difficult to obtain a crimped tow.

Preferably, the cooling and solidification includes supplying the filamentous spinning solution to a coagulation liquid in a coagulation bath via an air gap zone.

Preferably, the temperature of the coagulation liquid is less than or equal to 30°C.

Preferably, while the lyocell fiber precursor is obtained by cooling and solidification, the N-methylmorpholine-N-oxide is recovered, and the recovery rate of the N-methylmorpholine-N-oxide reaches more than 99.5%.

Preferably, the natural fiber raw material is selected from any one of wood fiber raw materials, bamboo fiber raw materials and cotton fiber raw materials.

The present application also provides a heat-not-burn cigarette filter, which includes the above-mentioned lyocell fiber tow for heat-not-burn cigarette filter. The heat-not-burn cigarette filter can be formed by only the lyocell fiber tow for heat-not-burn cigarette filter and forming paper, or a part of the structure of the heat-not-burn cigarette filter is composed of the lyocell fiber tow for heat-not-burn cigarette filter, and other filter Mouth structure.

The heat-not-burn cigarette filter prepared from the lyocell fiber bundle for the heat-not-burn cigarette filter of the present application has high permeability, small pressure drop, good smoking experience, and the filter will not undergo thermal collapse. It is completely biodegradable and environmentally friendly and pollution-free.

Preferably, the heat-not-burn cigarette filter is formed by rolling the above-mentioned lyocell fiber tow for heat-not-burn cigarette filter and forming paper. The lyocell fiber tow for heat-not-burn cigarette filter can be directly rolled to obtain a heat-not-burn cigarette filter with high permeability, low pressure drop and good smoking experience without combining with other filter structures. The prior art uses acetate fiber tow to prepare heat-not-burn cigarette filter. Even if the acetate fiber tow also adopts a high single denier and low total denier design, the heat-not-burn cigarette filter obtained is often difficult to meet the requirements. For example, there are still problems such as insufficient cooling effect, poor pressure drop stability, and easy thermal collapse.

Preferably, the draw resistance mean design range of the heat-not-burn cigarette filter is 2Pa/mm-20Pa/mm, for example, 2Pa/mm-8Pa/mm, or 5Pa/mm-10Pa/mm, or 10Pa/mm-20Pa/mm, or 8Pa/mm-15Pa/mm. According to the design requirements of cigarettes, the design requirements of 2Pa/mm-20Pa/mm are met, and the draw resistance fluctuation range of the filter rod is not the same.

The present application also provides a heat-not-burn cigarette, comprising the above-mentioned heat-not-burn cigarette filter.

The heat-not-burn cigarette prepared by the heat-not-burn cigarette filter of the present application has a high smoke concentration and a good sense of satisfaction when smoking, and because lyocell fiber removes lignin during the production process, it does not produce unpleasant feelings such as woody smell.

The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

Example 1

Example 1 First, a lyocell fiber tow for a heat-not-burn cigarette filter is provided, wherein the single denier is controlled at 10.0D, the total denier is controlled at 16000D, the cross section of the lyocell fiber tow is elliptical, and the eccentricity e of the ellipse is 0.1.

Example 1 also provides a method for preparing a lyocell fiber tow for a heat-not-burn cigarette filter, comprising:

The bamboo fiber raw material is purified by chemical processing to obtain natural fiber pulp;

The N-methylmorpholine-N-oxide aqueous solution is mixed with the natural fiber slurry and put into a twin-screw extruder to make Lyocell. Spinning solution;

The lyocell spinning solution is filtered and then wet-spun by dry jet spinning using a spinneret with multiple holes. The lyocell spinning solution is kept at a spinning temperature of 105° C. at the spinning nozzle of the annular spinneret, and then spinning is performed while adjusting the discharge amount of the spinning solution and the spinning rate, so that the single filament fineness of the final lyocell is 10.0 denier.

The filamentary spinning solution discharged from the spinning nozzle is supplied to the coagulation liquid in the coagulation bath through the air gap zone to cool and coagulate to obtain the lyocell fiber precursor, and the temperature of the coagulation liquid is less than or equal to 30° C.

The filaments are fully soaked in oil and squeezed, and then dried with a drying roller at 150°C to obtain lyocell multifilaments;

The lyocell multifilament obtained above was heated while passing through a steam box, and then crimped in a stuffer box by a pressure roller to obtain the lyocell fiber bundle of Example 1, with the crimp number of 15 per inch.

Example 1 also provides a heat-not-burn cigarette filter, which is made of the lyocell fiber bundle for the heat-not-burn cigarette filter of Example 1 and high-transparency forming paper. The filling amount of the lyocell fiber bundle is between 0.4-0.5g/piece. The length of the filter is 120mm and the circumference is 16.8mm.

Embodiment 1 also provides a heat-not-burn cigarette, comprising a smoking section, a supporting section and the filter tip for the heat-not-burn cigarette of embodiment 1.

Example 2

Example 2 First, a lyocell fiber tow for a heat-not-burn cigarette filter is provided, wherein the single denier is controlled at 10.0D, the total denier is controlled at 25000D, the cross-section of the lyocell fiber tow is elliptical, and the eccentricity e of the ellipse is 0.1.

Embodiment 2 also provides a method for preparing a lyocell fiber tow for a heat-not-burn cigarette filter, comprising:

The bamboo fiber raw material is purified by chemical processing to obtain natural fiber pulp;

The aqueous solution of N-methylmorpholine-N-oxide is mixed with the natural fiber slurry and put into a twin-screw extruder to prepare a lyocell spinning solution;

The lyocell spinning solution is filtered and then wet-spun by dry jet spinning using a spinneret with multiple holes. The lyocell spinning solution is kept at a spinning temperature of 105° C. at the spinning nozzle of the annular spinneret, and then spinning is performed while adjusting the discharge amount of the spinning solution and the spinning rate, so that the single filament fineness of the final lyocell is 10.0 denier.

The filamentary spinning solution discharged from the spinning nozzle is supplied to the coagulation liquid in the coagulation bath through the air gap zone to cool and coagulate to obtain the lyocell fiber precursor, and the temperature of the coagulation liquid is less than or equal to 30° C.

The filaments are fully soaked in oil and squeezed, and then dried with a drying roller at 150°C to obtain lyocell multifilaments;

The lyocell multifilament obtained above is heated while passing through a steam box, and then crimped in a stuffing box by a pressure roller. The lyocell fiber tow of Example 2 was obtained, and the number of crimps was 20 per inch.

Example 2 also provides a heat-not-burn cigarette filter, which is made of the lyocell fiber bundle for the heat-not-burn cigarette filter of Example 2 and high-transparency forming paper. The filling amount of the lyocell fiber bundle is between 0.45-0.6g/piece. The length of the filter is 120mm and the circumference is 19.8mm.

Embodiment 2 also provides a heat-not-burn cigarette, comprising the same smoking section and supporting section as those of embodiment 1 and the filter for the heat-not-burn cigarette of embodiment 2.

Example 3

Example 3 First, a lyocell fiber tow for a heat-not-burn cigarette filter is provided, wherein the single denier is controlled at 10.0D, the total denier is controlled at 35000D, the cross section of the lyocell fiber tow is elliptical, and the eccentricity e of the ellipse is 0.1.

The preparation method of a lyocell fiber tow for a heat-not-burn cigarette filter provided in Example 3 is carried out with reference to the preparation method in Example 1, wherein the crimp number of the obtained tow is 25 per inch.

Example 3 also provides a heat-not-burn cigarette filter, which is made by rolling the lyocell fiber bundle for the heat-not-burn cigarette filter of Example 3 and high-transparency forming paper. The filling amount of the lyocell fiber bundle is between 0.5-0.7g/piece. The length of the filter is 120mm and the circumference is 24mm.

Embodiment 3 also provides a heat-not-burn cigarette, comprising the same smoking section and supporting section as those of embodiment 1 and the filter for the heat-not-burn cigarette of embodiment 3.

Example 4

Example 4 First, a lyocell fiber tow for a heat-not-burn cigarette filter is provided, wherein the single denier is controlled at 20.0D, the total denier is controlled at 35000D, the cross-section of the lyocell fiber tow is elliptical, and the eccentricity e of the ellipse is 0.1.

The preparation method of a lyocell fiber tow for a heat-not-burn cigarette filter provided in Example 4 is carried out with reference to the preparation method in Example 1, wherein the crimp number of the obtained tow is 25 per inch.

Example 4 also provides a heat-not-burn cigarette filter, which is made by rolling the lyocell fiber bundle for the heat-not-burn cigarette filter of Example 4 and high-transparency forming paper. The filling amount of the lyocell fiber bundle is between 0.5-0.7g/piece. The length of the filter is 120mm and the circumference is 24mm.

Embodiment 4 also provides a heat-not-burn cigarette, comprising the same smoking section and supporting section as those of embodiment 1 and the filter for the heat-not-burn cigarette of embodiment 4.

Example 5

Example 5 First, a lyocell fiber tow for a heat-not-burn cigarette filter is provided, wherein the single denier is controlled at 30.0D, the total denier is controlled at 35000D, the cross-section of the lyocell fiber tow is elliptical, and the eccentricity e of the ellipse is 0.1.

The preparation method of a lyocell fiber tow for a heat-not-burn cigarette filter provided in Example 5 is carried out with reference to the preparation method in Example 1, wherein the crimp number of the obtained tow is 25 per inch.

Example 5 also provides a heat-not-burn cigarette filter, which is made of the lyocell fiber bundle for the heat-not-burn cigarette filter of Example 5 and high-transparency forming paper. The filling amount of the lyocell fiber bundle is between 0.5-0.7g/piece. The length of the filter is 120mm and the circumference is 24mm.

Embodiment 5 also provides a heat-not-burn cigarette, comprising the same smoking section and supporting section as those of embodiment 1 and the filter for the heat-not-burn cigarette of embodiment 5.

Comparative Example 1

Comparative Example 1: First, a heat-not-burn cigarette filter made of polylactic acid and forming paper is provided. The length of the filter is 120 mm, the circumference is 24 mm, and the filling amount of polylactic acid is between 0.5-0.7 g/cigarette.

Comparative Example 1 also provides a heat-not-burn cigarette prepared from the heat-not-burn cigarette filter of Comparative Example 1, and the cigarette core material and cigarette structure are consistent with those in Example 1.

Comparative Example 2

Comparative Example 2 first provides a heat-not-burn cigarette filter made of acetate fiber and forming paper, the single denier of the acetate fiber is controlled at 10.0D, the total denier is controlled at 35000D, the cross-section is Y-shaped, the length of the filter is 120mm, the circumference is 24mm, and the filling amount of the acetate fiber tow is between 0.5-0.7g/cigarette.

Comparative Example 2 also provides a heat-not-burn cigarette prepared from the heat-not-burn cigarette filter of Comparative Example 2, and the cigarette core material and cigarette structure are consistent with those in Example 1.

Comparative Example 3

Comparative Example 3: First, a paper filter tip is provided which is made of semi-crepe paper and forming paper. The length of the filter tip is 120 mm, the circumference is 24 mm, and the filling amount of the semi-crepe paper is between 0.5-0.7 g/piece.

Comparative Example 3 also provides a heat-not-burn cigarette prepared from the heat-not-burn cigarette filter of Comparative Example 3, and the cigarette core material and cigarette structure are consistent with those in Example 1.

The parameters of the heat-not-burn cigarette filters of the embodiments and comparative examples are shown in Table 1.

Table 1 Parameters of the heat-not-burn cigarette filters of the embodiments and comparative examples

The heat-not-burn cigarettes of the embodiments and comparative examples were tested, including a draw resistance test and a sensory smoking effect test, and the appearance changes of the heat-not-burn cigarette filters were observed after the tests were completed. The test results are shown in Table 2.

According to Table 2, the heat-not-burn cigarette prepared by the lyocell fiber tow of the present application has a large smoke volume, no odor when inhaled, no contradiction between draw resistance and end face gap, and is not easy to collapse due to heat. The smoke volume of the heat-not-burn cigarettes of Comparative Examples 1 to 3 is poor; polylactic acid, acetate fiber, and semi-crepe paper filter tips are all prone to heat collapse, and the semi-crepe paper filter tip will produce a woody odor when inhaled, and will also produce a contradiction between draw resistance and end face gap.

Among them, the actual picture of the filter of comparative example 2 after smoking is shown in Figure 2, and it can be seen that the end face of the filter collapses due to heat. The actual picture of the filter of embodiment 1 after smoking is shown in Figure 3, and the end face of the filter is normal without thermal collapse.

Table 2 Test results of heat-not-burn cigarettes of various embodiments and comparative examples

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims (10)

A lyocell fiber tow for a heat-not-burn cigarette filter, characterized in that the single denier of the lyocell fiber tow is controlled within the range of 10.0D-30.0D, the total denier of the lyocell fiber tow is controlled within the range of 10000D-40000D according to the circumferential size required by the filter rod, and the cross-section of the lyocell fiber tow is elliptical or circular. The lyocell fiber tow for a heat-not-burn cigarette filter according to claim 1, characterized in that the eccentricity e of the ellipse is in the range of 0<e<1. A method for preparing a lyocell fiber tow for a heat-not-burn cigarette filter, comprising: The aqueous solution of N-methylmorpholine-N-oxide is mixed with the natural fiber slurry and put into a twin-screw extruder to prepare a lyocell spinning solution; The lyocell spinning solution is filtered and then wet-spinned by a spinneret with multiple holes, the lyocell spinning solution is kept at a spinning temperature of 100° C. to 110° C. at the spinning nozzle of the spinneret, and the discharge amount and spinning rate of the lyocell spinning solution are adjusted so that the single filament fineness of the final lyocell fiber is within a range of 10.0 denier to 30.0 denier; The filamentary spinning solution discharged from the spinning nozzle is cooled and solidified to obtain the lyocell fiber precursor; The lyocell fiber raw yarn is subjected to water washing, oiling and drying treatments; The treated lyocell fiber raw yarn is curled to produce the lyocell fiber tow for the heat-not-burn cigarette filter according to claim 1 or 2. The method for preparing a lyocell fiber tow for a heat-not-burn cigarette filter according to claim 3, wherein the lyocell fiber tow has 15 to 30 crimps per inch. The method for preparing a lyocell fiber tow for a heat-not-burn cigarette filter according to claim 3 is characterized in that the cooling and solidification includes supplying the filamentary spinning solution to the coagulation liquid in the coagulation bath via an air gap zone. The method for preparing a lyocell fiber tow for a heat-not-burn cigarette filter according to claim 5, characterized in that the temperature of the coagulation liquid is less than or equal to 30°C. A heat-not-burn cigarette filter, characterized in that the heat-not-burn cigarette filter comprises the lyocell fiber tow for a heat-not-burn cigarette filter according to claim 1 or 2. The heat-not-burn cigarette filter according to claim 7 is characterized in that the heat-not-burn cigarette filter is formed by rolling the lyocell fiber tow for the heat-not-burn cigarette filter according to claim 1 or 2 and forming paper. The heat-not-burn cigarette filter according to claim 7 is characterized in that the draw resistance range of the heat-not-burn cigarette filter is 2Pa/mm-20Pa/mm. A heat-not-burn cigarette, characterized by comprising the heat-not-burn cigarette filter according to any one of claims 7 to 9.