Porous smoking material wrapper and smoking article containing same

Abstract

A smoking material wrapper is provided that has micropores and, when divided into three regions at equal intervals from an upstream end of a smoking article, has a larger average porosity in the region closer to the downstream. According to one embodiment of the present invention, the micropores have a pore size of 10 μm to 50 μm and are formed by a perforation method using plasma. The smoking material wrapper not only maintains the functionality of the wrapping material due to low visibility, but also minimizes the dilution rate that decreases as the smoking material burns while maintaining the basic dilution rate when applied to a smoking article.

Description

[Technical Field]

[0001] The present invention relates to a porous smoking material wrapper and a smoking article including the same, and more particularly to a smoking material wrapper having micropores formed by separate perforations and a smoking article including the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0119033, filed on September 21, 2022, and incorporates all of the contents disclosed in the documents of that Korean patent application as part of this specification. [Background technology]

[0003] Generally, to manufacture smoking articles such as cigarettes that deliver nicotine through combustion, various types of leaf tobacco are first blended and processed to produce the desired aroma and flavor. The processed leaf tobacco is then chopped to produce cut tobacco leaves, which are then wrapped in a smoking material wrapper (or cigarette paper) to produce filterless cigarettes. A filter is then attached to the filterless cigarettes, if desired.

[0004] The filter may contain activated carbon, flavoring substances, etc., and may consist of a mono-filter or multiple filters. The filter is surrounded by a filter wrapper and connected to the tobacco shreds by tipping paper, and the tipping paper may contain fine pores.

[0005] The smoking material wrapper can be manufactured to have appropriate porosity and burnability to deliver target tar and nicotine during smoking, as well as to impart a tobacco-specific flavor. Although various smoking material wrappers have already been commercially available, improvements in functionality are still required. The inventors have completed the present invention after continuous research into smoking material wrappers. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent Publication No. 2007-0096027 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention provides a smoking material wrapper and a smoking article using the same, which can improve functionality when applied to a smoking article by forming micropores in the smoking material wrapper through separate perforations. [Means for solving the problem]

[0008] According to a first aspect of the present invention, there is provided a smoking material wrapper having micropores, wherein when a smoking article is divided into three regions at equal intervals from the upstream end of the applicable standard, the average porosity is greater in the region closer to the downstream.

[0009] In one embodiment of the present invention, the micropores have a pore size of 10 μm to 50 μm.

[0010] In one embodiment of the present invention, the micropores are formed by a plasma-based drilling method.

[0011] In one embodiment of the present invention, the micropores are aligned in a direction perpendicular to the application standard of the smoking article to form a set, and are divided into three regions at equal intervals from the upstream end of the application standard of the smoking article, with each region containing one or more sets.

[0012] In one embodiment of the present invention, the distance between adjacent sets is the same upstream and downstream as applied to smoking articles, or is longer upstream than downstream.

[0013] In one embodiment of the present invention, the porosity in the smoking material wrapper is controlled by the distance between micropores.

[0014] In one embodiment of the present invention, the porosity in the smoking material wrapper is controlled by the size of the micropores.

[0015] In one embodiment of the present invention, the smoking material wrapper is divided into three regions at equal intervals from the upstream end of the smoking article, with the average pore size being smaller in the more downstream regions.

[0016] In one embodiment of the invention, the smoking material wrapper does not exceed a porosity of 1,000 CU at any location.

[0017] In one embodiment of the invention, the smoking material wrapper has an average porosity of between 300 CU and 700 CU.

[0018] In one embodiment of the invention, the smoking material wrapper has an increasing porosity as it moves downstream from the upstream end of the application reference to the smoking article, and when the porosity reaches a maximum, it is maintained at that maximum.

[0019] In one embodiment of the invention, the smoking material wrapper exhibits an increasing porosity in the form of a quadratic or cubic function as one moves downstream from the upstream end of the smoking article.

[0020] In one embodiment of the present invention, the porosity of the smoking material wrapper increases as one moves downstream from the upstream end of the smoking material, reaching a peak at 60% to 80% of the length of the smoking material wrapper.

[0021] According to a second aspect of the present invention, there is provided a smoking article comprising a smoking material portion, a smoking material wrapper, a filter portion, a filter wrapper and tipping paper, wherein the smoking material wrapper is the smoking material wrapper described above. [Effects of the Invention]

[0022] The smoking material wrapper according to one embodiment of the present invention essentially uses a plasma perforation method to form small micropores, so that the locations of the micropores cannot be easily identified with the naked eye and visibility is not reduced, thereby maintaining functionality as a packaging material.

[0023] Furthermore, even if the same level of average porosity is applied, the smoking material wrapper can minimize the dilution rate that decreases as the smoking material portion burns while maintaining the basic dilution rate when applied to a smoking article through the efficient arrangement of micropores.

[0024] This allows the smoker to enjoy a more consistent smoking experience from the moment they start smoking until they finish. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a diagram illustrating a smoking article according to one embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing a smoking material wrapper having an adjusted porosity by adjusting the spacing between sets of micropores aligned in the vertical direction according to an application standard to a smoking article, according to one embodiment of the present invention. [Figure 3] 1 is a schematic diagram showing a smoking material wrapper in which the number of micropores within a set of micropores aligned in the vertical direction of an application standard to a smoking article is adjusted to control the porosity according to one embodiment of the present invention. [Figure 4] 1 is a schematic diagram illustrating a smoking material wrapper having controlled porosity by controlling the size of micropores within a set of micropores aligned in a direction perpendicular to the application standard of a smoking article, according to one embodiment of the present invention. [Figure 5] 1 is a graph showing the porosity distribution of smoking material wrappers according to Examples 1 and 2 and Comparative Examples 1 to 5. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments will be described in detail with reference to exemplary drawings. When assigning reference numerals to components in each drawing, it should be noted that identical components are assigned the same numerals as much as possible even if they are shown in different drawings. Furthermore, when describing embodiments, if a detailed description of related known structures or functions is deemed to hinder understanding of the embodiments, the detailed description will be omitted.

[0027] Furthermore, when describing components of an embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are merely used to distinguish the component from other components, and do not limit the nature, order, or sequence of the components. When a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, but that other components may also be "coupled," "coupled," or "connected" between each component.

[0028] Components included in one embodiment and components having common functions will be described using the same names in other embodiments. Unless otherwise specified, the description of one embodiment may also be applied to other embodiments, and detailed descriptions will be omitted to the extent that they overlap.

[0029] As used herein, the term "smoking article" may refer to an article capable of generating aerosol, such as a cigarette (cigarette), a cigar, etc. Smoking articles may include an aerosol-generating substance or an aerosol-forming substrate. Smoking articles may also include solid substances based on tobacco raw materials, such as flat tobacco, shredded tobacco, and reconstituted tobacco. Smoking substances may include volatile compounds. Smoking articles may include several segments each with their own functionality, and these segments are indicated by "... segments." As used herein, smoking articles may include not only combustible cigarettes, but also heated cigarettes used with an aerosol-generating device (not shown), such as an electronic cigarette device.

[0030] As used herein, the terms "upstream" and "downstream" are used to indicate the relative positions of segments constituting a smoking article with respect to the direction in which a user draws air using the smoking article. A smoking article includes an upstream end (i.e., the portion from which air enters) and an opposing downstream end (i.e., the portion from which air exits). When using a smoking article, a user can hold the downstream end of the smoking article in their mouth. The downstream end is located downstream of the upstream end, while the term "end" may also be described as "terminal end."

[0031] The present invention provides a smoking material wrapper for use as one component of a smoking article. For reference, Figure 1 provides a diagram showing a schematic configuration of a smoking article according to one embodiment of the present invention. The smoking article (100) generally comprises a smoking material portion (10) and a filter portion (20), the smoking material portion (10) being surrounded and wrapped by a smoking material wrapper (30a), and the filter portion (20) being surrounded and wrapped by a filter wrapper (30b). The wrapped smoking material portion and filter portion are connected by tipping paper (40).

[0032] The smoking material wrapper (30a) according to one embodiment of the present invention has improved functionality compared to conventional smoking material wrappers by including micropores added by additional perforation in addition to the natural pores that are essentially formed on the paper material. While the natural pores have a pore size of less than 10 μm, the micropores have a pore size of 10 μm or more. Therefore, the naturally occurring pores and the artificially added micropores can be clearly distinguished even with the naked eye.

[0033] According to one embodiment of the present invention, the micropores are formed by a plasma perforation method. The above-described method allows for the formation of micropores with smaller and more uniform sizes. Because the smoking material wrapper (30a) primarily serves to package the smoking material portion (10), it is required to not only function to prevent the contents from leaking out but also to have a high aesthetic appeal. The micropores formed by the plasma perforation method may have a pore size of 10 μm to 50 μm, 15 μm to 50 μm, or 20 μm to 50 μm. When the micropores have a pore size of 50 μm or less, the visibility of the smoking material wrapper is not significantly increased even when the micropores are formed, thereby maintaining the original functionality of the packaging material. Furthermore, the plasma perforation method does not significantly cause the paper to blacken around the micropores, and the aesthetic degradation caused by the perforations is not significantly reduced.

[0034] The micropores in the smoking material wrapper (30a) can be formed in various sizes, positions, numbers, etc., but even if the same number of micropores are formed, there may be differences in functionality depending on the position of the micropores, etc. One of the objects of the present invention is to maximize functionality even when a similar number of micropores are formed, thereby improving the performance of smoking articles when using a smoking material wrapper according to one embodiment of the present invention.

[0035] In this specification, the term "porosity" is used to describe the degree to which micropores are formed. Porosity is a physical property commonly used in the art to define the characteristics of paper, such as smoking material wrappers, and may also be referred to as air permeability. The porosity refers to the permeability of paper to air flow caused by a pressure difference between both sides of the paper, which may refer to the volume of air flowing through the paper per unit time, unit area, and pressure difference. Therefore, the porosity is expressed in cm 3 / (min·cm 2 These units are sometimes expressed in CORESTA units (CU), where 1 CU = 1 cm 3 / (min·cm 2 ·kPa). In this specification, porosity and average porosity are intentionally shown separately to clarify the large deviation depending on the measurement position when measuring porosity over an area larger than a unit area. Specifically, in this specification, porosity refers to the porosity over a unit area formed at a specific position and centered thereon, and average porosity refers to the porosity calculated by measuring the overall air permeability over an area larger than a unit area and then dividing the measured value by the unit area.

[0036] According to one embodiment of the present invention, when a smoking article is divided into three regions at equal intervals from the upstream end of the application reference, the region closer to the downstream has a greater average porosity. Unless micropores are symmetrically formed in the smoking material wrapper, the direction in which the smoking material wrapper is applied to the smoking article can significantly affect the functionality of the smoking material wrapper. Therefore, even if the smoking material wrapper itself has no particular orientation before being applied to the smoking article, the position of the smoking material wrapper is determined based on the orientation when applied to the smoking article. When the smoking material wrapper is divided into three regions at equal intervals from the upstream end of the application reference to the smoking article, the positional relationship of the three regions can be clearly identified in terms of upstream and downstream of the smoking article. If the most upstream region of the three regions is designated as the first region, the next most upstream region is designated as the second region, and the most downstream region is designated as the third region, the average porosity may increase in the order of the first region, the second region, and the third region. Since the third region is the part that can remain unburned for the longest time when the smoking article is burning, even if the same number of micropores are formed, forming a larger number of micropores in the third region can help improve functionality.

[0037] The micropores do not necessarily need to be regularly formed. However, when air flows from upstream to downstream within a smoking article during smoking, similar functionality can be achieved when identical micropores are applied at positions spaced a specific distance from the upstream end of the smoking article. Applying multiple micropores aligned vertically to the smoking article is advantageous for understanding the effect of the micropore position on functionality. This micropore application method can also help improve processability. According to one embodiment of the present invention, a plurality of the micropores are aligned vertically to the smoking article to form a set. When the smoking article is divided into three regions at equal intervals from the upstream end of the application, each region contains one or more sets. Here, vertical alignment of the micropores can be interpreted strictly, but vertical alignment can be achieved even if the centers of the micropores deviate from the vertical line by one or two micropore sizes, as long as an overall tendency toward vertical alignment is observed.

[0038] According to one embodiment of the present invention, the micropores are formed continuously from upstream to downstream. Here, "continuous" means that the average distance between adjacent micropores is the same or gradually decreases as the micropores move from upstream to downstream. For example, if the micropores are formed with a consistent tendency and no micropores are formed in a specific region, the average distance between adjacent micropores will increase significantly, and in this case, the micropores cannot be said to be formed continuously. When the micropores are applied to the smoking article in the form of sets aligned vertically in the applicable standard, if the micropores are formed continuously, the distance between adjacent sets will be the same upstream and downstream as in the applicable standard for the smoking article, or will be longer upstream than downstream.

[0039] The porosity of the smoking material wrapper can be controlled in various ways. Figures 2 to 4 are schematic views of a smoking material wrapper having micropores formed therein, through which exemplary methods of controlling the porosity of the smoking material wrapper can be seen. For reference, in Figures 2 to 4, the left side is the upstream direction and the right side is the downstream direction.

[0040] In Figure 2, each set is made up of the same size and number of micropores (H), and the distance between sets decreases as one moves from upstream to downstream. When the smoking material wrapper shown in Figure 2 is divided into three regions at equal intervals from the upstream end of the smoking article, the average porosity is greater in the regions closer to downstream.

[0041] In Figure 3, each set is composed of micropores (H) of the same size, and as one moves from upstream to downstream, the number of micropores in each set gradually increases while maintaining the distance between each set. When the smoking material wrapper shown in Figure 3 is divided into three regions at equal intervals from the upstream end of the applicable standard for smoking articles, the average porosity is greater in the region closer to downstream.

[0042] In Figure 4, each set is composed of the same number of micropores (H), and the micropores are formed by simultaneously decreasing the size of the micropores and the distance between each set. Although the smoking material wrapper shown in Figure 4 is divided into three regions at equal intervals from the upstream end of the applicable standard for the smoking article, it cannot be clearly stated that the average porosity is greater in the region closer to the downstream. However, if the effect of increasing porosity due to a shorter distance between each set is greater than the effect of a decrease in porosity due to a decrease in the size of the micropores, the average porosity may be greater.

[0043] As seen in Figures 2 to 4, the porosity of the smoking material wrapper can be adjusted by controlling the distance between micropores and the size of the micropores. Increasing the number of micropores ultimately shortens the average distance between micropores, so porosity can be adjusted by controlling the distance between micropores. When high porosity is required in the smoking material wrapper, the porosity can be increased by significantly shortening the distance between micropores while reducing the size of the micropores. If the distance between micropores is shortened while the size of the micropores is above a certain level, the visibility of the smoking material wrapper may increase, potentially reducing its functionality as a packaging material. According to one embodiment of the present invention, when the smoking material wrapper is divided into three regions at equal intervals from the upstream end of a smoking article, the average pore size is smaller in the regions closer to the downstream.

[0044] According to one embodiment of the present invention, the smoking material wrapper does not exceed a porosity of 1,000 CU at any location. Here, porosity refers to the porosity at a specific location, not the average porosity. Even if the average porosity is not high, if micropores are densely located near a specific location, the porosity may be significantly high. However, if the porosity exceeds 1,000 CU at a specific location, not only will the visibility at that location increase, but durability may also decrease, potentially reducing the functionality of the wrapping material.

[0045] According to one embodiment of the present invention, the smoking material wrapper has an average porosity of 300 CU to 700 CU, 350 CU to 650 CU, or 400 CU to 600 CU. Within these ranges, the introduction of micropores can enhance functionality, such as increasing the dilution rate. Exceeding these ranges can result in an excessive increase in the dilution rate and a decrease in the durability of the smoking material portion of the smoking article. As mentioned above, even if the average porosity is the same, the functionality can vary depending on the location of the micropores, so the placement of the micropores can be important.

[0046] According to one embodiment of the present invention, the porosity of the smoking material wrapper increases from the upstream end of the application to the smoking article toward the downstream end, and once the porosity reaches a maximum, it is maintained at that maximum. When micropores are formed near the upstream end of the application to the smoking material, it is preferable to position the micropores as far downstream as possible, since the micropores may disappear quickly during combustion. However, if the micropores are positioned only downstream, when the smoking material burns near the upstream end, the smoke generated during combustion may not be quickly diluted with air, resulting in poor air dilution at the initial stage of smoking. Therefore, it is preferable to maintain a certain level of micropores at the front of the smoking material. In consideration of this, to maximize the functionality of the micropore formation, it is preferable to increase the porosity from the upstream end toward the downstream end, and once the porosity reaches a maximum, it is preferable to maintain the porosity at that maximum. Here, the maximum point can be freely set according to the manufacturer's design, but it is preferable that it does not exceed a porosity of 1,000 CU. If the porosity does not reach its highest point until the downstream end of the smoking material section, the smoking material section can steadily increase.

[0047] According to one embodiment of the present invention, the porosity of the smoking material wrapper increases in the form of a quadratic or cubic function as it moves downstream from the upstream end of the smoking article. Here, a quadratic or cubic function means that the porosity increases in proportion to the square of the distance or the cube of the distance. Therefore, in the case of a cubic function, even if the porosity increases in the form of a cubic function graph, if there is no inflection point at a distance of 0, this is not included. Unlike a linear function, in a quadratic or cubic function, the porosity increases rapidly with distance and can reach a peak more quickly. Once the peak is reached, the porosity no longer increases and remains at the peak.

[0048] According to one embodiment of the present invention, the porosity of the smoking material wrapper increases as the smoking material moves downstream from the upstream end, reaching a peak at 60% to 80% of the length of the smoking material wrapper. When the porosity reaches a peak at a constant level, the rate of decrease in dilution can be minimized compared to when the porosity reaches a peak too quickly or too slowly.

[0049] As described above, the functionality ensured by the formation of micropores may be further enhanced by combining it with other components of the smoking article. In the smoking article, other technical features, excluding the technical feature for the formation of micropores, can be easily combined and used within the scope generally known in the art.

[0050] The smoking material portion (10) wrapped by the smoking material wrapper (30a) can be filled with smoking material such as raw tobacco, flakes, or a mixture of leaf tobacco and flakes. Processed smoking material can be filled into the smoking material portion (10) in sheet or shredded form. The smoking material portion (10) can have an elongated rod shape, and its length, circumference, and diameter can be adjusted to sizes commonly used in the art, taking into account the amount of smoking material to be filled, user preferences, etc., without particular limitation. The smoking material portion (10) may contain at least one aerosol-generating substance selected from the group consisting of glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oleyl alcohol. The smoking material portion (10) can also contain other additives, such as flavorants, humectants, and / or acetate compounds. The aerosol-generating substance and additives can be incorporated into the smoking material.

[0051] In addition to the smoking material portion 10, the smoking article 100 also includes a filter portion 20, which is located downstream of the smoking material portion 10 and serves as a filter through which the aerosol generated by the smoking material portion 10 passes just before the user inhales it. The filter portion 20 can be made of various materials, for example, a cellulose acetate filter. The filter portion 20 can be a cellulose acetate filter that is not flavored, or a TJNS (transfer jet nozzle system) filter that is flavored.

[0052] According to one embodiment of the present invention, the filter member (20) may be a tubular structure having a hollow interior. The filter member (20) may also be manufactured by inserting a film, tube, or other structure made of the same or a different material into the interior (e.g., hollow) of the filter member (20). While the filter member (20) according to one embodiment of the present invention is shown in FIG. 1 as a mono-filter consisting of a single filter, this is not limiting. For example, the filter member (20) may be configured as a dual filter or triple filter having two acetate filters to enhance filtering efficiency. Furthermore, although not shown, the filter member (20) may contain a crushable capsule (not shown) inside, which has a membrane-like structure encasing a liquid containing a flavoring.

[0053] The smoking material part 10 can be packaged in the smoking material wrapper 30a. A portion of the tobacco smoke generated during the combustion process of a typical smoking material part 10 is released into the atmosphere through the smoking material wrapper 30a before passing through the cigarette filter, resulting in unpleasant sidestream smoke for secondhand smokers. Various attempts have been made to reduce sidestream smoke, such as adding fillers such as magnesium oxide, titanium oxide, cerium oxide, aluminum oxide, calcium carbonate, and zirconium carbonate to cigarette paper. However, simply using these fillers to reduce sidestream smoke can result in a decrease in smoking experience, poor smoking stability, and poor ash solidification. It has been difficult to solve these problems through the appropriate combination of fillers. The smoking material wrapper 30a according to one embodiment of the present invention uses a filler containing a mixture of magnesium oxide (MgO and / or Mg(OH)2) and calcium carbonate (CaCO3) to reduce sidestream smoke while simultaneously preventing poor smoking experience, poor ash solidification, and poor ash solidification.

[0054] The filter part 20 can be wrapped in a filter part wrapper 30b. The filter part wrapper 30b can be made of oil-resistant wrapping paper, and the filter part wrapper 30b can further include aluminum foil on its inner surface.

[0055] The smoking material portion 10 wrapped in the smoking material portion wrapper 30a and the filter portion 20 wrapped in the filter portion wrapper 30b can be bound and wrapped with tipping paper 40. As shown in FIG. 1, the tipping paper 40 can surround at least a portion of the smoking material portion wrapper 30a (e.g., a downstream portion) and the outer periphery of the filter portion wrapper 30b. That is, at least a portion of the smoking material portion 10 and the filter portion 20 can be further wrapped and physically bound by the tipping paper 40. According to one embodiment of the present invention, the tipping paper 40 can be made of, but is not limited to, non-porous wrapping paper that is not oil-resistant. The tipping paper 40 can also contain a non-flammable material to prevent the filter portion 20 from burning.

[0056] The present invention will be described in more detail with reference to examples and comparative examples below. However, the present invention is not limited to these examples, and the scope of the present invention is not limited to these examples.

[0057] Example Example 1 For the purposes of this example, the smoking material wrapper surrounding the smoking material portion of a smoking article manufactured for testing was removed, and micropores of approximately 30 μm in size were formed in the same type of smoking material wrapper using a plasma perforation device (product of Tann Papier). The micropores were formed so that the average porosity of the smoking material wrapper was 500 CU, and the porosity increased quadratically with increasing distance from the upstream end of the smoking article. The porosity reached 1,000 CU at a point approximately 39 mm from the upstream end and remained at 1,000 CU thereafter. The smoking material wrapper with the micropores formed was then reattached to the smoking material portion to produce a smoking article. The smoking material portion of the smoking article had an axial length of approximately 51 mm and a circumference of approximately 23.7 mm.

[0058] Example 2 Smoking articles were manufactured in the same manner as in Example 1, except that micropores were formed in a different pattern than in Example 1. Specifically, in Example 2, the micropores were formed so that the average porosity of the smoking material wrapper was 500 CU, and the porosity increased according to a cubic function with increasing distance from the upstream end of the smoking article. The porosity reached 1,000 CU at a point approximately 34 mm from the upstream end, and remained at 1,000 CU thereafter.

[0059] Comparative Example 1 Smoking articles were manufactured in the same manner as in Example 1, except that micropores were formed in a different pattern than in Example 1. Specifically, in Comparative Example 1, micropores were formed so that the average porosity of the smoking material wrapper was 500 CU, and the porosity was stably maintained at 500 CU even when the smoking article was far from the upstream end of the applicable standard.

[0060] Comparative Example 2 Smoking articles were manufactured in the same manner as in Example 1, except that micropores were formed in a different pattern than in Example 1. Specifically, in Comparative Example 2, micropores were formed so that the average porosity of the smoking material wrapper was 500 CU, and the porosity increased linearly with increasing distance from the upstream end of the smoking article. The porosity reached 1,000 CU at a point approximately 51 mm from the upstream end.

[0061] Comparative Example 3 Smoking articles were manufactured in the same manner as in Example 1, except that micropores were formed in a different pattern than in Example 1. Specifically, in Comparative Example 3, micropores were formed so that the average porosity of the smoking material wrapper was 500 CU, and the porosity increased with increasing distance from the upstream end of the smoking article according to a cubic function with a different shape than in Example 2. Unlike in Example 2, the cubic function in Comparative Example 3 was adjusted so that the inflection point of the cubic function was located approximately 25.5 mm from the upstream end, and the porosity reached 1,000 CU at a point approximately 51 mm from the upstream end.

[0062] Comparative Example 4 Smoking articles were manufactured in the same manner as in Example 1, except that micropores were formed in a different pattern than in Example 1. Specifically, in Comparative Example 4, micropores were formed so that the average porosity of the smoking material wrapper was 500 CU, and curves of different patterns were connected starting from a point about 25.5 mm from the upstream end, with the porosity increasing with increasing distance from the upstream end. The porosity reached 1,000 CU at a point about 51 mm from the upstream end.

[0063] Comparative Example 5 Smoking articles were manufactured in the same manner as in Example 1, except that micropores were formed in a different pattern than in Example 1. Specifically, in Example 2, micropores were formed so that the average porosity of the smoking material wrapper was 500 CU, and the porosity increased exponentially with increasing distance from the upstream end of the smoking article. The porosity reached 1,000 CU at a point approximately 27 mm from the upstream end, and remained at 1,000 CU thereafter.

[0064] Specific porosity distributions of the smoking material wrappers according to Examples 1 and 2 and Comparative Examples 1 to 5 are shown in Figure 5 below. In Figure 5 below, the distance on the X-axis represents the distance from the upstream end of the wrapper when applied to a smoking article. For example, a distance of 0 m means that the wrapper is located at the upstream end when applied to a smoking article, and a distance of 0.025 m means that the wrapper is located 25 mm away from the upstream end when applied to a smoking article.

[0065] Experimental Example The physical properties of each of the smoking articles manufactured in Examples 1 and 2 and Comparative Examples 1 to 5 were analyzed using a cigarette quality tester (Kardien's Cigarette Quality Tester). The physical property analysis was performed when the smoking material remained at 51 mm (3 / 3 point), 34 mm (2 / 3 point), and 17 mm (1 / 3 point), respectively. The physical property analysis evaluated the dilution rate of the overall components based on the state when no micropores were formed, and the results are shown in Table 1 below. [Table 1]

[0066] As shown in Table 1, even though the average porosity of the smoking material wrapper was the same in both the Examples and Comparative Examples, the dilution rate varied at each point depending on the micropore pattern. Minimizing the decrease in dilution rate as smoking progresses can be important in providing a more consistent smoking experience from the moment a smoker starts smoking until the moment they finish smoking. From this perspective, when the porosity is increased in the form of a quadratic or cubic function from the upstream end of the smoking material, as in Examples 1 and 2, the decrease in dilution rate can be minimized even if the average porosity is the same.

[0067] As described above, even if the embodiments have been described by way of limited examples and drawings, those skilled in the art will appreciate that various modifications and variations may be made from the above description. For example, the described techniques may be performed in a different order than described, and / or the components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different manner than described, or may be substituted or replaced by other components or equivalents, and still achieve suitable results. [Explanation of symbols]

[0068] 10: Smoking Substances Section 20: Filter section 30a: Smoking substance wrapper 30b: Filter wrapper 40: Tip paper 100: Smoking articles H: Micropores

Claims

1. It has fine pores, When dividing a smoking article into three regions at equal intervals from the upstream end of the applicable standard, the region closer to the downstream has a larger average porosity, A smoking material wrapper, wherein the distance between the micropores and the size of the micropores gradually decrease in the region closer to the downstream side.

2. 2. The smoking material wrapper of claim 1, wherein the micropores have a pore size of 10 μm to 50 μm.

3. 10. The smoking material wrapper of claim 1, wherein the micropores are formed by a plasma perforation method.

4. The micropores are aligned in a vertical direction to form a set based on the application of the smoking article, 2. The smoking material wrapper of claim 1, wherein the smoking article is divided into three regions at equal intervals from the upstream end of the applicable standard, and each region contains one or more sets.

5. 5. The smoking material wrapper according to claim 4, wherein the distance between adjacent sets is the same upstream and downstream as applicable to smoking articles, or is longer upstream than downstream.

6. 10. The smoking material wrapper of claim 1, wherein the smoking material wrapper does not exceed a porosity of 1,000 CU at any location.

7. 2. The smoking material wrapper of claim 1, wherein the smoking material wrapper has an average porosity of 300 CU to 700 CU.

8. The smoking material wrapper of claim 6, wherein the porosity of the smoking material wrapper increases as the application reference moves from the upstream end to the downstream end of the smoking article, and when the porosity reaches a maximum point, it is maintained at that maximum point.

9. 10. The smoking material wrapper of claim 8, wherein the porosity of the smoking material wrapper increases in the form of a quadratic or cubic function as one moves downstream from the upstream end of the smoking article.

10. The smoking material wrapper of claim 6, wherein the porosity of the smoking material wrapper increases as the porosity moves downstream from the upstream end of the smoking material, reaching a maximum at a point between 60% and 80% of the length of the smoking material wrapper.

11. A smoking article comprising a smoking material portion, a smoking material wrapper, a filter portion, a filter wrapper, and tipping paper, wherein the smoking material wrapper is a smoking material wrapper according to claim 1.

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