KR20250028777A - Filter for cigarette, and smoking article comprising the same - Google Patents

Abstract

According to one aspect of the present invention, a cigarette filter comprising a paper sheet including pulp fibers; wherein the bulk of the paper sheet is 1.0 to 2.5 cm ³ /g, and the pulp fibers include 70 wt% or more of single fibers having an average coarseness of 15 mg/100 m or less.

Description

FILTER FOR CIGARETTE, AND SMOKING ARTICLE COMPRISING THE SAME

The present invention relates to a cigarette filter, and more particularly, to a cigarette filter and a smoking article including the same.

Filters used in cigarettes can be broadly classified into cellulose acetate filters, paper filters, and charcoal filters. Cellulose acetate filters commonly manufactured may include cellulose acetate tow. Among these, cellulose acetate filters can form a porous medium using uniformly spun fibers, and have been widely used as a filter material for smoking articles.

Meanwhile, in smoking products, the amount of smoke components introduced can be controlled by diluting the smoke inhaled by allowing outside air to enter through the perforations of the tip paper when smoking.

The inflow of outside air through the perforation had the problem of blocking the flow of air coming from upstream of the smoking article, causing the smoke components to be concentrated toward the center. As a result, the medium components were not evenly distributed in the mouth, making it difficult for smokers to feel the rich taste and flavor of the tobacco.

The purpose of the present invention is to provide a cigarette filter capable of enhancing the aroma and flavor of cigarettes by minimizing changes in the movement path of smoke components during smoking.

Another object of the present invention is to provide a cigarette filter having excellent particle removal ability.

Another object of the present invention is to provide a method for manufacturing the cigarette filter capable of implementing a high-density paper sheet.

Another object of the present invention is to provide a smoking article comprising the cigarette filter.

The purposes of the present invention are not limited to the purposes mentioned above, and other purposes and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. In addition, it will be easily understood that the purposes and advantages of the present invention can be realized by the means and combinations thereof indicated in the claims.

According to one aspect of the present invention for achieving the above object, a cigarette filter comprising a paper sheet including pulp fibers; wherein the bulk of the paper sheet is 1.0 to 2.5 cm ³ /g, and the pulp fibers include 70 wt% or more of single fibers having an average coarseness of 15 mg/100 m or less.

According to another aspect of the present invention, a method for manufacturing a cigarette filter is provided, comprising: (S1) a step of preparing raw material fibers; (S2) a step of dissociating and beating the raw material fibers to produce pulp fibers; and (S3) a step of producing a paper sheet with the pulp fibers; wherein the pulp fibers include 70 wt% or more of single fibers having an average roughness of 15 mg/100 m or less, and the step (S2) includes a step of beating the raw material fibers to a freeness of 14˚SR or more.

According to another aspect of the present invention, a smoking article is provided, comprising: a filter portion including a stain cross-section formed after smoking in accordance with the ISO 3308 test standard; wherein the stain cross-section and the filter cross-section are cut in a direction perpendicular to the longitudinal direction of the smoking article, and the cross-section of the filter portion includes a maximum inscribed circle defined by a maximum radius of the stain cross-section, and an area of the maximum inscribed circle is 65% or more based on the total area of the cross-section of the filter portion.

The above-mentioned solution to the problem does not enumerate all the features of the present invention. The various features of the present invention and the advantages and effects thereof can be understood in more detail by referring to the specific examples below.

According to one aspect of the present invention, a cigarette filter can be provided that can enhance the aroma and flavor of a cigarette by minimizing changes in the movement path of smoke components during smoking.

According to another aspect of the present invention, a cigarette filter having excellent particle removal ability can be provided.

In addition to the effects described above, the specific effects of the present invention are described below together with the specific contents for carrying out the invention.

FIG. 1 is a schematic diagram of a paper sheet included in a cigarette filter according to one embodiment of the present invention.
Figure 2 illustrates a smoking article according to one embodiment of the present invention.
FIG. 3 shows a cross-section of a filter portion and a stain cross-section formed after a smoking article is burned according to one embodiment of the present invention.
Figure 4 shows the flow of air inside smoking articles according to examples and comparative examples.

In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

The numerical range indicated by the term "to" in this specification refers to a numerical range that includes the values described before and after the term as the lower limit and the upper limit, respectively. When multiple numerical values are disclosed as the upper limit and the lower limit of an arbitrary numerical range, the numerical range disclosed in this specification can be understood as an arbitrary numerical range that uses any one of the multiple lower limit values and any one of the multiple upper limit values as the lower limit and the upper limit, respectively.

As used herein, a "smoking article" may mean any smokeable product or any product capable of providing a smoking experience, whether based on tobacco, a tobacco derivative, expanded tobacco, reconstituted tobacco or a tobacco substitute. For example, a smoking article may include smokeable products such as cigarettes, cigars and cigarillos. As another example, a smoking article may include a combustible smoking article or a heated smoking article.

In this specification, "Upstream" or "upstream direction" may mean away from the smoker's mouth, and "Downstream" or "downstream direction" may mean toward the smoker's mouth. The terms upstream and downstream may be used to describe the relative positions of elements that make up a smoking article.

In this specification, “longitudinal direction” may mean a direction corresponding to the longitudinal axis of the smoking article.

In this specification, "single fiber" may mean a fiber made of one type of raw pulp. Specifically, the single fiber may mean an individual fiber strand forming a pulp fiber.

In this specification, “mixed fiber” may mean fibers derived from two or more types of wood or plants, as opposed to single fibers.

1. Cigarette filter

According to one aspect of the present invention, there is provided a cigarette filter comprising a paper sheet including pulp fibers, wherein the bulk of the paper sheet is 1.0 to 2.5 cm ³ /g, and the pulp fibers include 70 wt% or more of single fibers having an average coarseness of 15 mg/100 m or less. There has been a problem in that the introduction of external air through a conventional perforation obstructs the flow of air introduced from upstream of a smoking article, causing smoke components to be concentrated toward the center. Accordingly, the medium components are not evenly distributed in the mouth, making it difficult for smokers to feel a rich tobacco taste and flavor. According to one aspect of the present invention, when the pulp fiber satisfies 70 wt% or more of single fibers having an average coarseness of 15 mg/100 m or less and the bulk of the paper sheet satisfies the above numerical range, the points where the fibers come into contact with each other to form hydrogen bonds increase, so that the bonding force between the fiber strands can increase, and thus a high-density paper sheet can be implemented. As a result, a portion of the air that flows in from the outside through the perforations can be blocked by the high-density paper sheet, making it difficult for it to move toward the center. As a result, due to the blocking action of the high-density paper sheet, smoke and/or aerosol is not concentrated in the center during the inhalation process but is evenly spread throughout, so that a rich tobacco taste and flavor can be enhanced.

Below, the configuration of the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a schematic diagram of a paper sheet included in a cigarette filter according to one embodiment of the present invention.

Referring to Fig. 1, the paper sheet (100) according to the present invention can maintain a compressed structure in a cigarette filter. When this compressed paper sheet (100) is unwound, it can be changed into a paper filter in the shape of a sheet.

The paper sheet (100) according to the present invention includes pulp fibers (10a). Here, the pulp fibers (10a) may be a collection of individual single fiber strands; or a collection of two or more types of single fiber strands having different average roughnesses.

In general, the average coarseness of fibers is one of the characteristics of natural fibers such as wood and plants. The higher the coarseness, the more bulky the paper sheet can exhibit. If the coarseness is low, the number of points where fibers come into contact with each other and form hydrogen bonds increases, which can reduce the porosity of the paper sheet, increase the tensile strength, and form an entanglement structure between fibers.

A single fiber according to the present invention may mean a fiber made of one or more raw fibers of wood and plants. Specifically, the single fiber may mean an individual fiber strand forming a pulp fiber.

The pulp fiber (10a) according to the present invention contains 70 wt% or more of single fibers having an average coarseness of 15 mg/100 m or less based on the total weight of the pulp fibers. Here, the average coarseness means the average mass per unit length of the fibers. Specifically, the average coarseness of the pulp fibers is a factor that can affect the bonding force between the fibers, and by controlling it together with the degree of beating described later, the porosity of the paper sheet can be changed. As the porosity of the paper sheet changes, the degree to which a portion of the external air introduced through the perforations is blocked by the paper sheet can change.

Specifically, the average coarseness of the single fiber is 15 mg/100 m or less, 14 mg/100 m or less, 13 mg/100 m or less, 12 mg/100 m or less, 11 mg/100 m or less, 10 mg/100 m or less, 9 mg/100 m or less, 8 mg/100 m or less, 7 mg/100 m or less, 6 mg/100 m or less, 5 mg/100 m or less, 4 mg/100 m or less, 3 mg/100 m or less, 2 mg/100 m or less, or 1 mg/100 m or less; 1 mg/100 m or more, 2 mg/100 m or more, 3 mg/100 m or more, 4 mg/100 m or more, 5 mg/100 m or more, 6 mg/100 m or more, 7 mg/100 m or more, 8 mg/100 m or more, 9 mg/100 m or more, 10 mg/100 m or more, 11 mg/100 m or more, 12 mg/100 m or more, 13 mg/100 m or more, or 14 mg/100 m or more; or any one of the plurality of lower limit values and any one of the plurality of upper limit values may be a range of any numerical values, each of which is taken as a lower limit value and an upper limit value, respectively. More specifically, the average roughness of a single fiber may be 1 to 15 mg/100 m, 2 to 14 mg/100 m, 3 to 13 mg/100 m, 4 to 12 mg/100 m, 5 to 11 mg/100 m, 6 to 10 mg/100 m, 6 to 9 mg/100 m, 6 to 8 mg/100 m, 6 to 7 mg/100 m or 6 to 6.8 mg/100 m. In some embodiments of the present invention, when the average roughness of the single fiber satisfies the numerical range, the points where the fibers contact each other to form hydrogen bonds increase, so that the bonding force between the fiber strands can increase, and accordingly, a high-density paper sheet can be implemented. As a result, the removal ability for phenol compounds such as hydroquinone, catechol, and resorcinol, nicotine, and particulate matter such as tar can be excellent. In addition, some of the air flowing in from the outside through the perforation may be blocked by the high-density paper sheet, making it difficult for it to move toward the center. As a result, the blocking action of the high-density paper sheet may cause smoke and/or aerosol to spread evenly throughout the inhalation process without being concentrated in the center, thereby enhancing the rich taste and flavor of the tobacco.

For example, the method for analyzing the average roughness of the single fiber may be an analysis method compliant with KS M ISO 23713.

For example, a single fiber satisfying the above average roughness range may be a fiber derived from Cedar, Eucalyptus, Birch, Elm, Chestnut, Oak or Walnut.

The content of single fibers having an average coarseness of 15 mg/100 m or less according to the present invention is 70 wt% or more, 71 wt% or more, 72 wt% or more, 73 wt% or more, 74 wt% or more, 75 wt% or more, 76 wt% or more, 77 wt% or more, 78 wt% or more, 79 wt% or more, 80 wt% or more, 81 wt% or more, 82 wt% or more, 83 wt% or more, 84 wt% or more, 85 wt% or more, 86 wt% or more, 87 wt% or more, 88 wt% or more, 89 wt% or more, 90 wt% or more, 91 wt% or more, 92 wt% or more, 93 wt% or more, 94 wt% or more, 95 wt% or more, 96 wt% or more, 97 wt% or more, 98 % or more, 99 wt% or more, or 100 wt% or more; or 100 wt% or less, 99 wt% or less, 98 wt% or less, 97 wt% or less, 96 wt% or less, 95 wt% or less, 94 wt% or less, 93 wt% or less, 92 wt% or less, 91 wt% or less, 90 wt% or less, 89 wt% or less, 88 wt% or less, 87 wt% or less, 86 wt% or less, 85 wt% or less, 84 wt% or less, 83 wt% or less, 82 wt% or less, 81 wt% or less, 80 wt% or less, 79 wt% or less, 78 wt% or less, 77 wt% or less, 76 wt% or less, 75 wt% or less, 74 wt% or less, 73 wt% or less, 72 wt% or less, or 71 wt% or less; Or, it may be a range of any numerical values where any one of the plurality of lower limits and any one of the plurality of upper limits are used as the lower limit and the upper limit, respectively. According to some embodiments of the present invention, when the content of the single fiber based on the total weight of the pulp fiber satisfies the numerical range, the points where the fibers come into contact with each other to form hydrogen bonds increase, so that the bonding force between the fiber strands may increase, and thus a high-density paper sheet may be implemented. As a result, the removal ability for phenol compounds such as hydroquinone, catechol, and resorcinol, and particulate matter such as nicotine and tar may be excellent. In addition, a portion of the air that flows in from the outside through the perforations may be blocked by the high-density paper sheet, making it difficult for it to move toward the center. As a result, due to the blocking action of the high-density paper sheet, the smoke and/or aerosol is not concentrated in the center during the inhalation process but is evenly spread throughout, so that the rich taste and flavor of the tobacco may be improved.

In some embodiments of the present invention, the pulp fibers may further include single fibers having an average coarseness of greater than 15 mg/100 m. For example, the content of the single fibers having an average coarseness of greater than 15 mg/100 m may be the remaining content excluding the content of the single fibers having an average coarseness of less than or equal to 15 mg/100 m. Specifically, the content of the single fibers having an average coarseness of greater than 15 mg/100 m may be 30% or less, 20% or less, 10% or less, 5% or less, or 1% or less, based on the total weight of the pulp fibers.

Meanwhile, the bulk of a paper sheet is a thickness value for the basis weight of the paper sheet. In general, the lower the porosity of the paper sheet, the lower the bulk of the paper sheet. In the present invention, the bulk of the paper sheet may vary depending on the degree of freedom in the process of refining the raw fiber. Accordingly, when the paper sheet is applied to a cigarette filter in a crimped state, the particle removal ability of the filter and the blocking action of the paper filter may vary.

According to some embodiments of the present invention, the bulk of the paper sheet (100) is 1.0 cm ³ /g or more, 1.1 cm ³ /g or more, 1.2 cm ³ /g or more, 1.3 cm ³ /g or more, 1.4 cm ³ /g or more, 1.5 cm ³ /g or more, 1.6 cm ³ /g or more, 1.7 cm ³ /g or more, 1.8 cm ³ /g or more, 1.9 cm ³ /g or more, 2.0 cm ³ /g or more, 2.1 cm ³ /g or more, 2.2 cm ³ /g or more, 2.3 cm ³ /g or more, 2.4 cm ³ /g or more, or 2.5 cm ³ /g or more; 2.5 cm ³ /g or less, 2.4 cm ³ /g or less, 2.3 cm ³ /g or less, 2.2 cm ³ /g or less, 2.1 cm ³ /g or less, 2.0 cm ³ /g or less, 1.9 cm ³ /g or less, 1.8 cm ³ /g or less, 1.7 cm ³ /g or less, 1.6 cm ³ /g or less, 1.5 cm ³ /g or less, 1.4 cm ³ /g or less, 1.3 cm ³ /g or less, 1.2 cm ³ /g or less, or 1.1 cm ³ /g or less; or any numerical range where any one of the plurality of lower limit values and any one of the plurality of upper limit values are respectively used as the lower limit value and the upper limit value; can be. Specifically, the bulk of the paper sheet may be 1.0 to 2.5 cm ³ /g, 1.1 to 2.4 cm ³ /g, 1.2 to 2.3 cm ³ /g, 1.3 to 2.2 cm ³ /g, 1.4 to 2.1 cm ³ /g, 1.5 to 2.0 cm ³ /g, 1.6 to 1.9 cm ³ /g, 1.6 to 1.8 cm ³ /g, 1.6 to 1.7 cm ³ /g or 1.61 to 1.7 cm ³ /g. According to some embodiments of the present invention, when the bulk of the paper sheet satisfies the numerical range, the points where fibers contact each other to form hydrogen bonds increase, so that the bonding force between fiber strands can increase, and thus a high-density paper sheet can be implemented. This can result in excellent removal performance for phenol compounds such as hydroquinone, catechol, and resorcinol, particulate matter such as nicotine, and tar. In addition, some of the air flowing in from the outside through the perforation can be blocked by the high-density paper sheet, making it difficult for it to move toward the center. As a result, due to the blocking action of the high-density paper sheet, the smoke and/or aerosol is not concentrated in the center during the inhalation process, but is evenly distributed throughout the entire body, thereby improving the rich taste and flavor of the tobacco.

The average length of the pulp fibers according to the present invention may be a factor affecting the bonding strength between fiber strands. Accordingly, the high-density characteristics of the paper sheet can be controlled.

According to some embodiments of the present invention, the average length of the pulp fibers may be 2 mm or less, 1.5 mm or less, 1 mm or less, or 0.5 mm or less; or 0.5 mm or more, 1 mm or more, or 1.5 mm or more, or any numerical range in which any one of the plurality of lower limits and any one of the plurality of upper limits are each a lower limit value and an upper limit value. According to some embodiments of the present invention, since the average length of the pulp fibers satisfies the numerical range, the contact between the fibers in the fiber suspension during the manufacturing process of the paper sheet can be controlled to an appropriate level, thereby controlling the degree of filtration. Accordingly, the bulk and porosity of the paper sheet can be affected, and thus the blocking action of the paper sheet can be improved when the paper sheet is applied to a filter in a crimped state.

According to some embodiments of the present invention, the porosity of the paper sheet (100) is 1,500 CU or less, 1,400 CU or less, 1,300 CU or less, 1,200 CU or less, 1,100 CU or less, 1,000 CU or less, 900 CU or less, 800 CU or less, 700 CU or less, 600 CU or less, 500 CU or less, 400 CU or less, 300 CU or less, 200 CU or less, or 100 CU or less; 1,400 CU or more, 1,300 CU or more, 1200 CU or more, 1100 CU or more, 1000 CU or more, 900 CU or more, 800 CU or more, 700 CU or more, 600 CU or more, 500 CU or more, 400 CU or more, 300 CU or more, 200 CU or more, or 100 CU or more; a range of any numerical values, wherein any one of the plurality of lower limit values and any one of the plurality of upper limit values are respectively the lower limit value and the upper limit value; can be. More specifically, the porosity of the paper sheet (100) may be 100 to 1,500 CU, 100 to 1,000 CU, 100 to 900 CU, 100 to 800 CU, 100 to 700 CU, 100 to 600 CU, 100 to 500 CU, 100 to 400 CU, or 100 to 350 CU. According to some embodiments of the present invention, when the porosity of the paper sheet satisfies the numerical range, the removal ability for particulate matter such as phenol compounds such as hydroquinone, catechol, and resorcinol, nicotine, and tar may be excellent. In addition, a portion of the air that flows in from the outside through the perforations may be blocked by the high-density paper sheet, making it difficult for it to move toward the center. As a result, the blocking action of the high-density paper sheet causes smoke and/or aerosol to spread evenly throughout the entire tobacco during the inhalation process rather than being concentrated in the center, thereby enhancing the rich taste and flavor of tobacco.

According to some embodiments of the present invention, a moisturizer may be applied to at least a portion of the surface of the paper sheet (100) to implement a desired degree of pressure drop. Here, the pressure drop may refer to the resistance of air felt when a user bites a smoking article and inhales air. Since the smoking satisfaction felt by the user may vary depending on the pressure drop, there is a need to implement a target pressure drop. For example, the moisturizer may include at least one of glycerin, guar gum, starch, methyl cellulose, ethylene vinyl acetate (EVA), gum arabic, and propylene glycol. For example, the content of the moisturizer applied to at least a portion of the surface of the paper sheet may be 0.5 mg/mm to 5 mg/mm.

According to some embodiments of the present invention, the cigarette filter may further include granules to improve the bonding strength between the moisturizer and the paper sheet. Specifically, the granules may be introduced and settled on the surface of the paper sheet (100) to improve the bonding strength between the moisturizer and the paper sheet. For example, the granules may include a coating layer formed on the surface to prevent the granules from being broken or crushed by external impact. In one example, the coating layer may comprise microcrystalline cellulose, anhydrous lactose, Cellactose 80 (co-processed 75% microcrystalline cellulose and 25% lactose), Isomalt, dibasic dihydrate calcium phosphate, calcium carbonate, calcium lactate, dibasic anhydrous calcium phosphate, tribasic calcium phosphate, calcium silicate, calcium sulfate, carbomer, calcium carboxymethylcellulose, sodium carboxymethylcellulose, cellulose, silicified microcrystalline cellulose, cellulose acetate, ceratonia, Copovidone, Corn starch, Pregelatinized starch, Dextrate, Dextrin, Dextrose, Erythritol, Ethylcellulose, Fructose, Fumaric acid, Glyceryl monooleate, Glyceryl monostearate, Glyceryl palmitostearate, Hydroxyethyl cellulose, Hydroxyethyl methyl cellulose, Hydroxypropyl betadex, Hydroxypropyl cellulose, Hydroxypropyl starch, Hypromellose, Hypromellose acetate succinate, Kaolin, Lactitol, Lactose anhydrous, Lactose monohydrate, Magnesium Carbonate, Magnesium Oxide, Maltitol, Maltodextrin, Maltose, Mannitol, Methylcellulose, Pectin, Polaxamer, Polycarbophil, Polydextrose, Poly(DL-Lactic Acid), Polyethylene Glycol, Polyethylene Oxide, Polymethacrylate, Polyoxyglyceride, Polyvinyl Alcohol, Povidone, Shellac, Simethicone, Sodium Alginate, Sodium Chloride, Sorbitol, Starch, Pregelatinized Starch, Sucrose, Sugar Spheres, Sulfobutyl Ether B-Cyclodextrin, Titanium Dioxide, Trehalose, Microcrystalline Wax, White Wax, Yellow Wax, Xanthan Gum, Xylitol, Beeswax, Candelilla, It may include at least one or more of Carnauba, Caraway, Sugarcane wax, Myrtle wax, Gum Arabic, Locust bean wax, Guar gum, Alginate, Carrageenan and Pectin.

According to some embodiments of the present invention, the paper sheet (100) is formed by being rolled into a cylindrical shape, and may have a circumference of 20 to 25 mm. For example, the paper sheet may be formed by rolling up paper that has been crimped by crimping the original paper, and may be manufactured by rolling the original paper so that it has a cylindrical shape when rolled. In this case, the circumference of the paper sheet may be the circumference of the bottom surface after being rolled into a cylindrical shape.

2. Method for manufacturing cigarette filters

According to another aspect of the present invention, a method for manufacturing a cigarette filter is provided, comprising the steps of (S1) preparing raw material fibers; (S2) dissociating and refining the raw material fibers to produce pulp fibers; and (S3) producing a paper sheet with the pulp fibers; wherein the pulp fibers include 70 wt% or more of single fibers having an average roughness of 15 mg/100 m or less, and the step (S2) includes a step of refining the raw material fibers to a freeness of 14˚SR or more. The above-described parts and repeated descriptions are briefly described or omitted.

(S1) Step for preparing raw fibers:

The raw material fiber according to the present invention may be a fiber manufactured by processing wood and/or plants before being microfiberized. Specifically, the method of processing wood and/or plants is not particularly limited and may be a mechanical pulping method or a chemical pulping method. For example, the raw material fiber may be a fiber in a state before a single fiber derived from wood or plants is microfiberized; or a fiber in a state before a sub-pulp fiber is microfiberized.

(S2) Step of manufacturing pulp fiber by dissociating and refining raw fiber:

Disintegration refers to the process of further breaking down the cut raw fibers into smaller pieces and stirring them with water to completely separate the fibers. Refining refers to the process of cutting and splitting the fibers in water to give the disintegrated raw fibers a certain degree of fine fiberization in order to impart superfineness to them. The characteristics of the finely fiberized pulp fibers may vary depending on the disintegration and refining methods and degrees, which may ultimately affect the structure and properties of the paper sheet. The more refining is done, the higher the freeness, and the less refining is done, the lower the freeness. Here, the freeness is an indicator that quantitatively determines how much the fibers are refinished. The strength of the paper can be increased through pulp fibers manufactured with high freeness, and the bonding of the fiber strands can be increased, so that dense and relatively strong paper can be manufactured. On the other hand, the density of the fiber strands can be lowered through pulp fibers manufactured with low freeness, so that relatively soft paper can be manufactured.

According to some embodiments of the present invention, in the process of refining the raw material fiber, the degree of freedom may be 14˚SR or more, 15˚SR or more, 16˚SR or more, 17˚SR or more, 18˚SR or more, 19˚SR or more, 20˚SR or more, 21˚SR or more, 21˚SR or more, 22˚SR or more, 23˚SR or more, 24˚SR or more, or 25˚SR or more; 45˚SR or less; 40˚SR or less, 35˚SR or less, 30˚SR or less, or any numerical range where any one of the plurality of lower limit values and any one of the plurality of upper limit values are each set as a lower limit value and an upper limit value, respectively. Specifically, in the process of refining the raw material fiber, the degree of freedom may be 14 to 40˚SR, 15 to 39˚SR, 16 to 38˚SR, 17 to 37˚SR, 20 to 35˚SR, 21 to 33˚SR, 22 to 30˚SR, 24 to 29˚SR, 25 to 29˚SR, 26 to 29˚SR, 27 to 29˚SR, or 28.1 to 29˚SR. According to some embodiments of the present invention, when the degree of freedom satisfies the numerical range in the process of refining the raw material fiber, the number of points where the fibers come into contact with each other to form hydrogen bonds increases, so that the bonding force between the fiber strands may increase, and thus a high-density paper sheet may be implemented. Due to this, some of the air flowing in from the outside through the perforation may be blocked by the high-density paper sheet, making it difficult for it to move toward the center. As a result, the blocking action of the high-density paper sheet may cause smoke and/or aerosol to spread evenly throughout the inhalation process rather than being concentrated toward the center, thereby enhancing the rich taste and flavor of tobacco.

The pulp fiber according to the present invention is a fiber strand distributed within the paper sheet as the final product, and may be a fiber that has been finely fiberized through a dissociation and refining process. The description related to the characteristics of the pulp fiber is omitted as it is redundant.

(S3) A step of manufacturing a paper sheet using the above pulp fibers;

The method for manufacturing a cigarette filter according to the present invention comprises the step of (S3) manufacturing a paper sheet using the pulp fibers. Specifically, a general paper machine or papermaking machine commercially available in the relevant technical field can be used as a means for manufacturing a paper sheet using the pulp fibers.

Specifically, the pulp fibers include at least 70 wt% of single fibers having an average roughness of 15 mg/100 m or less. Here, the pulp fibers may additionally include other fibers in addition to the single fibers.

Specifically, the bulk of the paper sheet may be 1.0 to 2.5 cm ³ /g. Specifically, the porosity of the paper sheet may be 1,500 CU or less.

Specifically, the average length of the pulp fibers may be 2 mm or less.

3. Smoking items

According to another aspect of the present invention, there is provided a smoking article, comprising: a filter portion including a stain cross-section formed after smoking in accordance with the ISO 3308 test standard; wherein the stain cross-section and the filter cross-section are cut in a direction perpendicular to the longitudinal direction of the smoking article, and the cross-section of the filter portion includes a maximum inscribed circle defined by a maximum radius of the stain cross-section, and an area of the maximum inscribed circle is 65% or more based on the total area of the cross-section of the filter portion. Here, the "filter portion" can be replaced with a cigarette filter according to some embodiments described above.

Hereinafter, the configuration of the present invention will be described in more detail with reference to FIGS. 2 and 3.

Figure 2 illustrates a smoking article according to one embodiment of the present invention.

FIG. 3 shows a cross-section and a stain cross-section of a filter portion formed after a smoking article is burned according to one embodiment of the present invention.

Referring to FIG. 2, a smoking article (200) according to the present invention includes a first part (210) and a second part (220). Specifically, the first part (210) and the second part (220) may be arranged sequentially along the longitudinal direction of the smoking article (200). More specifically, the first part (210) may be arranged upstream of the second part (220). For example, the first and second parts (210, 220) may have a cylindrical shape.

The second part (200) according to the present invention may further include a wrapper (250). In this case, the wrapper (250) may wrap at least one of the first part (210) and the paper sheet (100), and specifically, may wrap a part of the first part (210) and the entirety of the paper sheet (100).

The first part (210) according to the present invention includes a medium capable of generating smoke and/or aerosol when burned. Specifically, the mainstream smoke generated when the first part (210) is burned can be inhaled by the user through the second part (220) described later from the first part (210) in the longitudinal direction of the smoking article (200).

For example, the medium is not particularly limited and may be a common smoke and/or aerosol generating material commonly used in the relevant technical field. Specifically, the medium may include tobacco raw materials such as tobacco leaf pieces, tobacco stems, and materials processed therefrom. As a more specific example, the medium may include ground tobacco leaves, expanded stems, tobacco cut tobacco (e.g., tobacco cut tobacco, tobacco sheet cut tobacco), tobacco sheets (e.g., tobacco sheet), and the like.

According to some embodiments of the present invention, the medium may further include one or more additives from among a humectant and a flavoring agent. For example, the humectant may maintain moisture in the medium at an appropriate level to soften the unique taste and enrich the amount of atomization. Specifically, the humectant may include at least one or more of glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oleyl alcohol. For example, the flavoring agent may be added to enhance flavor. Specifically, the flavoring agent may include licorice, sucrose, fructose syrup, isosweetener, cocoa, lavender, cinnamon, cardamom, celery, fenugreek, cascarilla, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, mint oil, cinnamon, caraway, cognac, jasmine, chamomile, menthol, cinnamon, ylang ylang, sage, spearmint, ginger, coriander, clove extract (or clove material), or coffee.

The second part (220) according to the present invention may include a filter part that performs a filtering function for smoke and/or aerosol generated from the first part (210). Specifically, the second part (220) may be located downstream of the first part (210) and connected to the downstream end of the first part (210).

The wrapper (250) according to the present invention may be arranged on the surface of the paper sheet (100) in a cylindrical shape, and specifically, may wrap the paper sheet (100). Specifically, the wrapper (250) may wrap the filter portion, and the wrapper (250) may include one or more perforations (250h). According to some embodiments of the present invention, since the wrapper (250) is provided with one or more perforations (250h), the effect of the high-density paper sheet may be further increased. Specifically, a portion of the air flowing in from the outside through the perforations may be blocked by the high-density paper sheet, making it difficult for it to move toward the center. As a result, due to the blocking action of the paper sheet, the smoke and/or aerosol may not be concentrated in the center during the inhalation process but may be evenly spread throughout, thereby improving the rich taste and flavor of the tobacco.

The wrapper (250) according to the present invention may include a first wrapper (251) wrapping the paper sheet (100) and a second wrapper (252) wrapping the first wrapper (251).

The first wrapper (251) according to the present invention is formed to surround a paper sheet (100) that functions as a filter as a filter paper, and can support and package the paper sheet (100). For example, the porosity of the first wrapper (251) is not particularly limited, but may be 15,000 to 35,000 CU.

The second wrapper (252) according to the present invention can support and package the first wrapper (251) by surrounding the first wrapper (251). Specifically, the second wrapper (252) can support and package the paper sheet (100) as a result by being indirectly connected to the paper sheet (100) through the first wrapper (251).

One or more perforations (250h) according to the present invention can control the inflow and outflow of external air. Specifically, the second wrapper (252) may be provided with the one or more perforations (250h). For example, a method for forming the one or more perforations (250h) is not particularly limited and may be a general method in the relevant technical field. Specifically, the method for forming the perforations may include a method such as laser processing or mechanical processing.

Referring to FIGS. 2 and 3, the stain cross-section (St) according to the present invention is a cross-section of a stain pattern formed after a smoking article (200) is smoked in accordance with the ISO 3308 test standard, and may be a cross-section cut in a direction perpendicular to the longitudinal direction of the smoking article. For example, a method for analyzing the stain cross-section may be a method of observing a stain included in a cross-section of a bent portion of a filter portion after smoking with the naked eye and a digital microscope.

The stain cross-section (St) according to the present invention can define a maximum inscribed circle (C2) defined by a maximum radius (Rmax) in the stain formed after smoking. Here, the maximum radius (Rmax) can mean the farthest distance among the stain cross-sections (St) based on the center point of the filter portion. As a concept contrasting with the maximum radius (Rmax), the minimum radius (Rmin) can mean the shortest distance among the stain cross-sections (St) based on the center point of the filter portion. In this case, the stain cross-section (St) can include a minimum inscribed circle (C1) defined by the minimum radius (Rmin).

The area of the maximum inscribed circle (C2) according to the present invention is 65% or more, 66% or more, 67% or more, 68% or more, 69% or more, 70% or more, 71% or more, 72% or more, 73% or more, 74% or more, 75% or more, 76% or more, 77% or more, 78% or more, 79% or more, 80% or more, 81% or more, 82% or more, 83% or more, 84% or more, 85% or more, 86% or more, 87% or more, 88% or more, 89% or more, 90% or more, 91% or more, 92% or more, 93% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more of the total area of the cross-section (C3) of the filter portion; 100% or less, 99% or less, 98% or less, 97% or less, 96% or less, 95% or less, 94% or less, 93% or less, 92% or less, 91% or less, 90% or less, 89% or less, 88% or less, 87% or less, 86% or less, 85% or less, 84% or less, 83% or less, 82% or less, 81% or less, 80% or less, 79% or less, 78% or less, 77% or less, 76% or less, 75% or less, 74% or less, 73% or less, 72% or less, 71% or less, 70% or less, 69% or less, 68% or less, 67% or less, or 66% or less, or any one of the plurality of lower limit values and any one of the plurality of upper limit values being the lower limit value and the upper limit value, respectively; may be, and more specifically, 65% or more, 65 to 95%, 70 to 85%, 75 to 80%, 76 to 78% or 77 to 78%. According to some embodiments of the present invention, when the area of the maximum inscribed circle (C2) is less than the numerical range based on the entire area of the cross-section (C3) of the filter portion, the flow of air introduced from the upstream of the smoking article may be interrupted due to the introduction of external air through the perforations, which may cause a problem in that the smoke components are concentrated toward the center. Accordingly, the medium components may not be evenly distributed in the mouth, which may cause a problem in that it is difficult for the smoker to feel a rich tobacco taste and flavor.

The cross-section (C3) of the filter portion according to the present invention is a cross-section of the filter portion formed after the smoking article (200) is smoked in accordance with the ISO 3308 test standard, and may be a cross-section cut in a direction perpendicular to the longitudinal direction of the smoking article. For example, a method for analyzing the stain cross-section may be a method of observing a stain included in the curved cross-section of the filter portion after smoking with the naked eye and a digital microscope. Specifically, the cross-section (C3) of the filter portion may be a curved cross-section of a crimped paper sheet (100); or a curved cross-section of a structure composed of a paper sheet (100) and a first wrapper (251) wrapping the paper sheet (100).

According to some embodiments of the present invention, the maximum radius (Rmax) of the maximum inscribed circle (C2) may be 0.8 times or more, 0.8 to 0.9 times, 0.85 to 0.9 times, 0.86 to 0.89 times, or 0.87 to 0.88 times the radius (Rc) of the cross section (C3) of the filter portion. According to some embodiments of the present invention, when the maximum radius (Rmax) of the maximum inscribed circle (C2) satisfies the numerical range, a portion of the air flowing in from the outside through the perforation may be blocked by the high-density paper sheet, making it difficult for the air to move toward the center. As a result, due to the blocking action of the high-density paper sheet, the smoke and/or aerosol is not concentrated in the center during the inhalation process but is evenly spread throughout, thereby improving the rich taste and flavor of tobacco.

Meanwhile, the air dilution rate of smoking articles can be calculated using the following equation 1.

[Formula 1]

Air dilution rate (%) = (Fv/Ft) x 100

In the above equation 1, Ft is the total volume of the final mainstream smoke, and Fv is the volume of external air introduced through the perforation.

According to some embodiments of the present invention, the air dilution rate of the smoking article (200) may be 20% or more, specifically 20 to 90%, 20 to 80%, 30 to 70%, 40 to 60%, 45 to 60%, 50 to 60%, 55 to 60%, or 57 to 60%. Specifically, when the air dilution rate of the smoking article (200) satisfies the above numerical range, the smoke and/or aerosol is evenly spread throughout the entire area without being concentrated in the center during the inhalation process due to the blocking action of the high-density paper sheet, thereby enhancing the rich taste and flavor of tobacco.

According to another embodiment of the present invention, the second portion (220) may include a plurality of segments. For example, the smoking article (200) may further include a third portion (not shown) interposed between the first portion (210) and the second portion (220). For example, the third portion may include a cooling element.

According to one embodiment of the present invention, the cooling element may be a cylindrical tube formed of paper material and including a hollow portion. Specifically, polylactic acid may be coated on the inner surface of the tube. According to some embodiments of the present invention, by coating the inner surface of the tube with polylactic acid, the mainstream smoke and/or aerosol of tobacco generated by ignition of the first portion (210) may be cooled more effectively.

According to another embodiment of the present invention, the cooling element may be formed of a biodegradable polymer material, and specifically may be formed of polylactic acid fibers.

According to another embodiment of the present invention, the cooling element may be a cellulose acetate filter.

Hereinafter, embodiments of the present invention will be described in detail so that a person having ordinary skill in the art to which the present invention pertains can easily implement the present invention, but this is only an example, and the scope of the rights of the present invention is not limited by the following contents.

[Experimental example: Evaluation of characteristics of smoking items]

Smoking articles of the same Tar. were manufactured under the conditions described in Table 1 below, and smoking articles using a filter of the same suction resistance were manufactured under the conditions described in Table 2, and the characteristics of the smoking articles were evaluated using the methods described below.

1) Total particle matter (TPM), Tar Removal Efficiency (TRE) and Nicotine Removal Efficiency (NRE)

To evaluate the particle removal ability, the perforations of the cigarette were blocked and the cigarette was smoked under the conditions of a puff volume of 35 ml, duration of 2 sec, and interval of 60 sec. After passing through the filter, the smoke components captured on the Cambridge pad and the components filtered by the filter were measured and calculated as TPM, TRE, and NRE using precision electronic and GC (Gas Chromatography) analysis equipment.

2) The maximum inscribed circle and the maximum radius of the maximum inscribed circle defined by the stain cross section.

In accordance with the ISO 3308 test standard, the area of the maximum inscribed circle (C2) defined by the stain cross-section (St) formed after smoking and the total area of the cross-section (C3) of the filter section were photographed using a digital microscope and then measured (see Fig. 3).

3) Air dilution rate

The air dilution rate of smoking articles can be calculated using the following equation 1.

[Formula 1]

Air dilution rate (%) = (Fv/Ft) x 100

In the above equation 1, Ft is the total volume of the final mainstream smoke, and Fv is the volume of external air introduced through the perforation.

division Comparative Example 1 Comparative Example 2 Example 1 Filter (length) CA filter (27mm) Low density paper sheet (27mm) High density paper sheet (27mm) Paper sheet porosity (CU) - 2,900CU 350CU Bulk of paper sheet (cm ³ /g) - 2.65 1.61 Yeosu-do (˚SR) - 13.5 28.1 Average illuminance (mg/100m) - 26.7 6.8 Area of the greatest inscribed circle (C2) 26% of the total cross-sectional area of the filter section 59% of the total cross-sectional area of the filter section 77% of the total cross-sectional area of the filter section Maximum radius of the largest inscribed circle (Rmax) 0.51 times the cross-sectional radius of the filter section (Rc) 0.77 times the cross-sectional radius of the filter section (Rc) 0.88 times the cross-sectional radius of the filter section (Rc) Air dilution rate (%) 72% 68% 57% Tar. (mg) 2.9 2.9 2.9

division Comparative Example 1 Comparative Example 2 Example 1 Filter (length) CA filter (27mm) Low density paper sheet (27mm) High density paper sheet (27mm) Suction resistance (mm _H2O ) 420 420 420 Paper sheet porosity (CU) - 2,900CU 350CU Bulk of paper sheet (cm ³ /g) - 2.65 1.61 Average illuminance (mg/100m) - 26.7 6.8 TPM(%) 62% 76% 83% TRE(%) 56% 72% 80% NRE(%) 44% 68% 76%

Fig. 4 shows the flow of air in smoking articles according to examples and comparative examples. Repeated descriptions of parts described above in Figs. 2 and 3 are omitted.

Referring to Fig. 4, when the high-density paper sheet of Example 1 is included in the filter section, air introduced through the perforations (250h) is blocked by the high-density paper sheet, thereby minimizing the influence of smoke and/or aerosol flow introduced from the upstream end of the external air introduced through the perforations. Accordingly, it can be confirmed that the area of the tar zone is further expanded.

On the other hand, when the CA filter of Comparative Example 1 and the low-density paper sheet of Comparative Example 2 are included in the filter section, the effect of blocking the air introduced through the perforations is reduced, so that the external air introduced through the perforations interferes with the flow of smoke and/or aerosol introduced from the upstream end, and thus the area of the tar zone is relatively narrowed.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

10a: Pulp fiber 100: Paper sheet
200: Smoking Articles 210: Part 1
220: Part 2 250: Rapper
251: 1st rapper 252: 2nd rapper
250h: Perforation C3: Cross section of filter section
C2: Greatest inscribed circle C1: Least inscribed circle
Rc: Radius of the cross-section of the filter section St: Stain cross-section
Rmin: minimum radius Rmax: maximum radius

Claims (11)

A cigarette filter comprising a paper sheet comprising pulp fibers;
The bulk of the above paper sheet is 1.0 to 2.5 cm ³ /g,
The above pulp fibers,
Containing at least 70 wt% of a single fiber having an average coarseness of 15 mg/100 m or less,
Filter for cigarettes.
In the first paragraph,
The average length of the above pulp fibers is 2 mm or less.
Filter for cigarettes.
In the first paragraph,
The porosity of the above paper sheet is 1,500 CU or less.
Filter for cigarettes.
(S1) Step of preparing raw fiber;
(S2) a step of dissociating and refining the above raw material fibers to produce pulp fibers; and
(S3) a step of manufacturing a paper sheet using the pulp fibers; including;
The above pulp fibers,
Containing at least 70 wt% of a single fiber having an average roughness of 15 mg/100 m or less,
The above step (S2) is,
Comprising a step of refining the raw material fiber to a degree of 14˚SR or higher,
Method for manufacturing a cigarette filter.
In paragraph 4,
The bulk of the above paper sheet is 1.0 to 2.5 cm ³ /g.
Method for manufacturing a cigarette filter.
In paragraph 4,
The porosity of the above paper sheet is 1,500 CU or less.
Method for manufacturing a cigarette filter.
In paragraph 4,
The average length of the above pulp fibers is 2 mm or less.
Method for manufacturing a cigarette filter.
A smoking article including a filter section including a stain cross-section formed after smoking in accordance with the ISO 3308 test standard;
The above stain cross-section and the cross-section of the filter portion are cut in a direction perpendicular to the length direction of the smoking article,
The cross-section of the above filter portion includes a maximum inscribed circle defined by the maximum radius of the stain cross-section,
The area of the maximum inscribed circle is 65% or more of the total cross-sectional area of the filter section.
Smoking items.
In Article 8,
The maximum radius of the above maximum inscribed circle is at least 0.8 times the radius of the cross-section of the above filter section.
Smoking items.
In Article 8,
With an air dilution rate of 20% or more,
Smoking items.
In Article 8,
Further comprising a wrapper surrounding the above filter portion;
The above wrapper comprises one or more perforations,
Smoking items.