Aerosol product
Patent Information
- Application Number
- PCT/CN2025/122980
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-04-17
- Filing Date
- 2025-09-22
- Publication Date
- 2026-10-22
Smart Images
Figure CN2025122980_22102026_PF_FP_ABST
Abstract
Description
An aerosol product
[0001] Cross-references to related applications
[0002] This application claims priority to Chinese Patent Application No. 202510483293.1, entitled "An Aerosol Product", filed on April 17, 2025 with the China National Intellectual Property Administration, the entire contents of which are incorporated herein by reference. Technical Field
[0003] This application relates to the field of heated cigarette technology, and more specifically, to an aerosol product. Background Technology
[0004] Smoking products are a class of products that form aerosols through various methods, mainly including two categories: traditional ignition-type smoking products and new heated non-combustible smoking products. In the field of heated non-combustible cigarette products, the preparation processes of aerosol generating matrices exhibit diverse characteristics. These include matrices made from thin sheets produced by dry processes, papermaking processes, slurry processes, and rolling processes, which are then cut into shreds and rolled. They also include integrated aerosol generating matrices produced through extrusion or casting processes.
[0005] However, existing one-piece molded aerosol generation matrices generally suffer from structural homogeneity, with high density and thickness and low porosity. This structural characteristic hinders aerosol release during heating, resulting in slow release rates and uneven distribution, leading to unsatisfactory atomization and significantly impacting the user's smoking experience. These technical bottlenecks urgently need to be overcome through material innovation and process improvement to enhance the overall performance of heated tobacco products. Summary of the Invention
[0006] This application provides an aerosol product that can solve the problems of difficult, slow, and uneven aerosol release and poor atomization effect caused by the large density and thickness and low porosity of the aerosol generation matrix medium in heated cigarettes.
[0007] The embodiments of this application can be implemented as follows:
[0008] The purpose of this application is to provide an aerosol article comprising: an aerosol generating matrix, a functional segment, and an outer coating layer, wherein the aerosol generating matrix is configured to generate aerosols, the functional segment includes a filter segment configured for filtration, and the outer coating layer is configured to encapsulate and fix the aerosol generating matrix and the functional segment, wherein the aerosol generating matrix is composed of at least one of particles of different particle sizes, flake-like components, and fibrous components.
[0009] Optionally, the functional segment further includes a hollow cavity configured to cool and store aerosols, wherein the hollow cavity is selected from the aerosol generating matrix or an integral structure composed of one or more hollow cavities.
[0010] Optionally, the aerosol generating matrix has an integral columnar structure with a circular or polygonal cross-section.
[0011] Optionally, the aerosol generating matrix comprises 20%-80% particulate components with a particle size less than 125 μm, 20%-60% particulate components with a particle size between 150 μm and 600 μm, and 20%-60% particulate components with an area of 0.785 mm². 2 -12.56mm 2 It consists of at least one of the following: a sheet-like component or 20%-60% of a fibrous component with a length between 0.5 mm and 12 mm.
[0012] Optionally, when the aerosol generating matrix is composed of particulate components, the particulate components with a particle size of less than 125 μm are powders of crushed plant materials, and the particles with a particle size between 150 μm and 600 μm are regular or irregular spherical structures. Its composition includes at least one of crushed plant materials and inorganic fillers.
[0013] When the aerosol generating matrix is composed of sheet-like components, the area is 0.785 mm². 2 -12.56mm 2 The flaky components include at least one of plant fragments, reconstituted tobacco leaves, and fibrous paper slices;
[0014] When the aerosol generating matrix is composed of fibrous components, the fibrous components with a length between 0.5 mm and 12 mm include at least one of plant fibers, reconstituted tobacco leaves, and fibrous materials obtained by slicing fiber paper.
[0015] Optionally, the aerosol generating matrix has through holes configured for aerosol flow, the through holes penetrating both ends of the aerosol generating matrix along its length and perpendicular to the cross-section of the aerosol generating matrix, and each through hole is independent of the others.
[0016] Optionally, the channels of the through holes are all parallel to each other along the length direction of the aerosol generating matrix.
[0017] Optionally, the sum of the cross-sectional areas of the through holes accounts for 50%-60% of the cross-sectional area of the aerosol generating matrix. The shape and cross-sectional area of each through hole are the same, and the cross-sectional shape is either circular or a regular polygon. The area of a single through hole accounts for 3%-60% of the area of the aerosol generating matrix.
[0018] Optionally, all the through holes are distributed in an axisymmetric and / or centrosymmetric manner with respect to the center of the aerosol generating matrix.
[0019] Optionally, the through holes are both centrally symmetric and axisymmetric, and the number of axisymmetric axes is greater than one.
[0020] Optionally, adjacent through holes are separated by a spacer wall of the same thickness.
[0021] Optionally, adjacent through-holes are separated by spacer walls of equal thickness. The aerosol generating matrix has micropores, and the average cross-sectional area of the micropores in any cross-section of the aerosol generating matrix is 800 μm. 2 ~1200μm 2 between.
[0022] Optionally, the aerosol product includes an aerosol generating matrix, a filter section, a cavity section, and an outer coating layer; the aerosol generating matrix, the cavity section, and the filter section are arranged sequentially along the axial direction of the aerosol product; the outer coating layer completely covers the aerosol generating matrix, the cavity section, and the filter section.
[0023] Optionally, both the aerosol generating matrix and the functional segment are columnar structures with the same outer diameter and are coaxially arranged, with a circular or polygonal cross-section.
[0024] Based on the above technical solutions, this application has the following beneficial effects:
[0025] The aerosol product of this application employs an aerosol-generating matrix formed by mixing flake-like components of different particle sizes and areas with fibrous components of different lengths, resulting in an increased micropore volume. On one hand, this reduces the aerosol resistance passing through the micropores during aerosol release, accelerating the release process. On the other hand, the larger micropore volume allows for the storage of a portion of the aerosol, which is released along with newly formed aerosols during inhalation, increasing the total amount of aerosol released during inhalation and thus improving the flue gas concentration. Attached Figure Description
[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 is a schematic diagram of the first aerosol generation matrix structure according to an embodiment of this application;
[0028] Figure 2 is a schematic diagram of the second aerosol generation matrix structure according to an embodiment of this application;
[0029] Figure 3 is a schematic diagram of the cross-sectional structure of the third aerosol generation matrix according to an embodiment of this application;
[0030] Figure 4 is a schematic diagram of the cross-sectional structure of the fourth aerosol generation matrix according to an embodiment of this application;
[0031] Figure 5 is a schematic diagram of the cross-sectional structure of the fifth aerosol generation matrix according to an embodiment of this application;
[0032] Figure 6 is a schematic diagram of the cross-sectional structure of the sixth aerosol generation matrix according to an embodiment of this application;
[0033] Figure 7 is a schematic diagram of the cross-sectional structure of the seventh aerosol generation matrix according to an embodiment of this application;
[0034] Figure 8 is a schematic diagram of the cross-sectional structure of the eighth aerosol generation matrix according to an embodiment of this application;
[0035] Figure 9 is a schematic cross-sectional structure diagram of the first aerosol-generated product according to an embodiment of this application;
[0036] Figure 10 is a schematic diagram of the cross-sectional structure of the second type of aerosol-generated product according to an embodiment of this application.
[0037] Figure labeling: 10; aerosol generating matrix; 20; 150μm-600μm particulates; 30; particulates with a diameter less than 125μm; 301; area 0.785mm². 2- 12.56mm 2 40 is a sheet-like component; 50 is a fibrous component with a length of 0.5mm-12mm; 100 is an outer wrapping layer; 200 is a functional segment; 201 is a filter segment; and 202 is a cavity segment. Detailed Implementation
[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0039] The features and performance of this application will be further described in detail below with reference to the embodiments.
[0040] This application provides an aerosol product, as shown in Figures 9 and 10. The aerosol product includes an aerosol generating matrix 10, a functional section 200, and an outer coating layer 100. The aerosol generating matrix 10 is configured to generate aerosols. The functional section 200 includes a filter section 201 configured for filtration. The outer coating layer 100 is configured to encapsulate and fix the aerosol generating matrix 10 and the functional section 200. The functional section 200 further includes a hollow cavity 202 configured for cooling and storing aerosols. The hollow cavity 202 is selected from the aerosol generating matrix 10 or is an integral structure composed of one or more hollow cavities.
[0041] The aerosol generating matrix used in one of the aerosol products in this application embodiment is shown in Figures 1 to 8. The aerosol generating matrix is configured to generate aerosols when heated for inhalation by the user. The aerosol generating matrix is composed of at least one of particles of different sizes, flake-like components, and fibrous components. It has an integral columnar structure. The column shape can be cylindrical (i.e., the cross-sectional shape is circular), prismatic (i.e., the cross-sectional shape is polygonal), elliptical (i.e., the cross-sectional shape is elliptical), etc., and is not limited here.
[0042] As shown in Figure 9, the aerosol generating matrix 10 and the functional segment 200 are both columnar structures with the same outer diameter and are coaxially arranged, with a circular or polygonal cross-section.
[0043] As shown in Figure 10, the aerosol product includes an aerosol generating matrix 10, a filter section 201, a cavity section 202, and an outer coating layer 100; the aerosol generating matrix 10, the cavity section 202, and the filter section 201 are arranged sequentially along the axial direction of the aerosol product; the outer coating layer 100 completely covers the aerosol generating matrix 10, the cavity section 202, and the filter section 201.
[0044] In a specific embodiment, the aerosol generating matrix 10 can be composed solely of particles of different sizes, or it can be composed of particles of different sizes and flake components, particles of different sizes and fibrous components, or flake components and fibrous components, or all three can be combined.
[0045] In some preferred embodiments, the aerosol generating matrix 10 comprises 20%-80% particulate component 301 with a particle size less than 125 μm, 20%-60% particulate component 30 with a particle size between 150 μm and 600 μm, and 20%-60% particulate component 30 with an area of 0.785 mm². 2 -12.56mm 2 It comprises at least one of the following: 40 of sheet-like components or 50 of 20%-60% of fibrous components with a length between 0.5 mm and 12 mm.
[0046] For example, when the aerosol generating matrix 10 is composed of particulate components, the particulate component 301 with a particle size of less than 125 μm is powder after crushing plant raw materials, and the particles with a particle size between 150 μm and 600 μm are regular or irregular spherical structures, and its composition includes at least one of the particles after crushing plant raw materials and inorganic fillers.
[0047] When the aerosol generating matrix 10 is composed of sheet-like components, the area is 0.785 mm². 2- 12.56mm 2 The sheet-like component 40 includes at least one of plant fragments, reconstituted tobacco leaves, and fibrous paper slices;
[0048] When the aerosol generating matrix is composed of fibrous components, the fibrous components 50 with a length between 0.5 mm and 12 mm include at least one of plant fibers, reconstituted tobacco leaves, and fibrous materials obtained by slicing fiber paper.
[0049] In some preferred embodiments, the aerosol generating matrix 10 has through holes 20 configured for aerosol flow. The through holes 20 penetrate both ends of the aerosol generating matrix 10 along its length and are perpendicular to the cross-section of the aerosol generating matrix 10. Each through hole 20 is independent of each other, so that all channels are parallel to each other along the length of the aerosol generating matrix. The parallel through holes 20 can minimize the flow resistance of gas passing through the through holes.
[0050] In some preferred embodiments, the sum of the cross-sectional areas of the through holes 20 accounts for 50%-60% of the cross-sectional area of the aerosol generating matrix 10. The shape of each through hole 20 is the same as its cross-sectional area, and the cross-sectional shape is either a circle or a regular polygon. The area of a single through hole 20 accounts for 3%-60% of the area of the aerosol generating matrix 10.
[0051] Specifically, when the sum of the cross-sectional areas of all through holes 20 accounts for less than 50% of the cross-sectional area of the aerosol generating matrix 10, the aerosol generating matrix 10 between the through holes 20 becomes thicker, resulting in greater suction resistance. The aerosol release from the center of the aerosol generating matrix 10 between two through holes 20 is slow and difficult. When the sum of the cross-sectional areas of all through holes 20 accounts for more than 60% of the cross-sectional area of the aerosol generating matrix 10, the content of aerosol generating matrix 10 per unit volume is low, and the thickness of the aerosol generating matrix 10 between adjacent through holes 20 is thinner. During inhalation, the aerosol release is high in the first half, resulting in high smoke concentration, while the aerosol release is weak and the smoke concentration is low in the second half. Therefore, when the sum of the cross-sectional areas of all through holes 20 accounts for between 50% and 60% of the cross-sectional area of the aerosol generating matrix 10, the suction resistance is moderate, the consistency of aerosol release before and after inhalation is good, the aerosol release is balanced, and the smoke concentration is high, which can improve the user experience. Meanwhile, limiting the cross-sectional area of a single through-hole 20 to 3%-60% of the cross-sectional area of the aerosol generating matrix 10 can avoid the problem of through-hole deformation and closure due to the insertion of a heating source under the central heating method.
[0052] In some preferred embodiments, all through holes 20 are distributed in an axisymmetric and / or centrosymmetric manner with respect to the center of the aerosol generating matrix 10, preferably both centrosymmetric and axisymmetric, with more than one axis of symmetry. The centrosymmetric and axisymmetric distribution of through holes 20 with the same cross-sectional area and shape ensures uniform heating on both sides of the axis of symmetry and around the center of symmetry during heating. When the heating methods on both sides of the axis of symmetry and around the center of symmetry are consistent, the gas flow rate and volume through the through holes 20 are the same during suction, ensuring that the aerosol release rate and amount are the same at relative positions on both sides of the axis of symmetry and around the center of symmetry. This avoids the problem of excessively rapid aerosol release in a certain area of the aerosol generating matrix 10 due to large differences in the cross-sectional area of the through holes 20 and the thickness of the aerosol generating matrix 10 between through holes 20, resulting in low concentration in the latter half of the suction process.
[0053] In some preferred embodiments, spacer walls of uniform thickness are provided between adjacent through-holes 20 of the aerosol generating matrix 10. First, the uniform thickness of the spacer walls ensures even heat distribution within the matrix, improving heating uniformity and efficiency and preventing localized overheating or underheating. Second, this design enhances the structural stability of the matrix, making it less prone to deformation or damage during heating and extending its service life. Furthermore, spacer walls of uniform thickness contribute to more consistent aerosol output, improving user experience stability and satisfaction. Simultaneously, optimized airflow channels ensure smooth aerosol passage, reducing airflow resistance and improving suction smoothness. Finally, the uniform spacer wall thickness simplifies the manufacturing process, reduces production difficulty and cost, and improves product consistency and reliability.
[0054] In some preferred embodiments, the aerosol generating matrix 10 has micropores, and the average cross-sectional area of the micropores in any cross-section of the aerosol generating matrix 10 is 800 μm. 2 -1200μm 2 between.
[0055] This application employs an aerosol-generating matrix formed by mixing flake-like components of different particle sizes and areas with fibrous components of different lengths. This increases the micropore volume within the aerosol-generating matrix. On one hand, this reduces the aerosol resistance passing through the micropores during aerosol release, accelerating the release process. On the other hand, the larger micropore volume can store a portion of the aerosol, which is released along with newly formed aerosols during suction, increasing the total amount of aerosol released during suction and improving the flue gas concentration. However, the micropore area should not be too large; a micropore area greater than 1200 μm is acceptable. 2 At times, the low smoke concentration during inhalation affects the user's vaping experience. The micropore area is 800μm. 2- 1200μm 2 The effect of increasing concentration is most obvious when the concentration is between 10 and 20.
[0056] Example 1
[0057] As shown in Figure 1, in this embodiment, all the through holes 20 of the aerosol generating matrix 10 have circular cross-sections and are the same size and shape. The through holes 20 penetrate both ends of the aerosol generating matrix 10 along its length and are perpendicular to the cross-section of the aerosol generating matrix 10. Each through hole is independent of the others. Furthermore, there are spacers between adjacent through holes, and the thickness of the spacers is the same.
[0058] All the through holes 20 on the aerosol generating matrix 10 are distributed in an axially symmetrical and centrally symmetrical manner with respect to the center of the aerosol generating matrix 10, and the number of axially symmetrical axes is greater than one.
[0059] Example 2
[0060] As shown in Figures 2, 3, and 4, the aerosol generating matrix 10 of this embodiment is composed of particulate components, including 40%-80% particulate components 301 with a particle size less than 125 μm and 20%-60% particulate components 30 with a particle size of 150 μm-600 μm. All through-holes 20 on the aerosol generating matrix 10 have a hexagonal cross-section, are the same size and shape, and penetrate both ends of the aerosol generating matrix 10 along its length and are perpendicular to the cross-section of the aerosol generating matrix 10. Each through-hole is independent of the others. Furthermore, adjacent through-holes are separated by spacers of the same thickness.
[0061] All the through holes 20 on the aerosol generating matrix 10 are distributed in an axially symmetrical and centrally symmetrical manner with respect to the center of the aerosol generating matrix 10, and the number of axially symmetrical axes is greater than one.
[0062] Example 3
[0063] As shown in Figure 5, in this embodiment, the aerosol generating matrix 10 is largely the same as in Example 2, except that the aerosol generating matrix 10 consists of 40%-80% particles 301 with a particle size less than 125 μm and 20%-60% particles with an area of 0.785 mm². 2- 12.56mm 2 It consists of 40 flake-like components.
[0064] Example 4
[0065] As shown in Figure 6, in this embodiment, the aerosol generating matrix 10 is generally the same as in Example 2, except that the aerosol generating matrix 10 is composed of 40%-80% particulate component 301 with a particle size of less than 125 μm and 20%-60% fibrous component 50 with a length of 0.5 mm-12 mm.
[0066] Example 5
[0067] As shown in Figure 7, in this embodiment, the aerosol generating matrix 10 is generally the same as in Example 2, except that the aerosol generating matrix 10 is composed of 40%-60% particulate component 301 with a particle size of less than 125 μm, 20%-40% particulate component 30 with a particle size of 150 μm-600 μm, and 40%-60% fibrous component 50 with a length of 0.5 mm-12 mm.
[0068] Example 6
[0069] As shown in Figure 8, in this embodiment, the aerosol generating matrix 10 is largely the same as in Example 2, except that: the aerosol generating matrix 10 consists of 20%-40% particles 301 with a particle size less than 125 μm, 20%-40% particles 30 with a particle size of 150 μm to 600 μm, and 20%-40% particles with an area of 0.785 mm². 2 -12.56mm 2 It consists of 40% flaky components and 50% 20%-40% fibrous components with a length of 0.5mm-12mm.
[0070] Example 7
[0071] As shown in Figure 9, the aerosol product described in this embodiment is composed of the aerosol generating matrix 10, the outer wrapping layer 100, and the functional segment 200 from Example 6. The functional segment 200 is composed of the filter segment 201. The outer wrapping layer 100 wraps the aerosol generating matrix 10 and the functional segment 200 to form the aerosol product.
[0072] Example 8
[0073] As shown in Figure 10, the aerosol product described in this embodiment is composed of the aerosol generating matrix 10, the outer wrapping layer 100, and the functional segment 200 from Example 6. The functional segment 200 is composed of a filter segment 201 and a cavity segment 202. The outer wrapping layer 100 wraps the aerosol generating matrix 10, the filter segment 201, and the cavity segment 202 to form the aerosol product. The wrapping order is aerosol generating matrix 10, cavity segment 202, and filter segment 201.
[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. Industrial applicability
[0075] The aerosol product in this embodiment employs an aerosol-generating matrix formed by mixing flake-like components of different particle sizes and areas with fibrous components of different lengths, resulting in an increased micropore volume. On one hand, this reduces the aerosol resistance passing through the micropores during aerosol release, accelerating the release process. On the other hand, the larger micropore volume allows for the storage of a portion of the aerosol, which is released along with newly formed aerosols during inhalation, increasing the total amount of aerosol released during inhalation and thus improving the flue gas concentration.
Claims
1. An aerosol product, characterized in that, The aerosol product includes: an aerosol generating matrix, a functional segment, and an outer coating layer. The aerosol generating matrix is configured to generate aerosols. The functional segment includes a filter segment configured for filtration. The outer coating layer is configured to encapsulate and fix the aerosol generating matrix and the functional segment. The aerosol generating matrix is composed of at least one of particles of different sizes, flake-like components, and fibrous components.
2. The aerosol product according to claim 1, characterized in that, The functional section also includes a hollow cavity configured for cooling and storing aerosols, wherein the hollow cavity is selected from the aerosol generating matrix or is an integral structure composed of one or more hollow cavities.
3. The aerosol product according to claim 1, characterized in that, The aerosol generating matrix has an integral columnar structure with a circular or polygonal cross-section.
4. An aerosol product according to claim 3, characterized in that, The aerosol generating matrix consists of 20%-80% particulate components with a particle size less than 125 μm, 20%-60% particulate components with a particle size between 150 μm and 600 μm, and 20%-60% particulate components with an area of 0.785 mm². 2 -12.56mm 2 It consists of at least one of the following: a sheet-like component or 20%-60% of a fibrous component with a length between 0.5 mm and 12 mm.
5. An aerosol product according to claim 3, characterized in that, When the aerosol generating matrix is composed of particulate components, the particulate components with a particle size of less than 125 μm are powders of crushed plant raw materials, and the particles with a particle size between 150 μm and 600 μm are regular or irregular spherical structures. Its composition includes at least one of crushed plant raw materials and inorganic fillers. When the aerosol generating matrix is composed of sheet-like components, the area is 0.785 mm². 2 -12.56mm 2 The flaky components include at least one of plant fragments, reconstituted tobacco leaves, and fibrous paper slices; When the aerosol generating matrix is composed of fibrous components, the fibrous components with a length between 0.5 mm and 12 mm include at least one of plant fibers, reconstituted tobacco leaves, and fibrous materials obtained by slicing fiber paper.
6. An aerosol product according to claim 1, characterized in that, The aerosol generating matrix has through holes configured for aerosol flow. The through holes penetrate both ends of the aerosol generating matrix along its length and are perpendicular to the cross-section of the aerosol generating matrix. Each through hole is independent of the others.
7. An aerosol product according to claim 6, characterized in that, The channels of the through holes are all parallel to each other along the length direction of the aerosol generation matrix.
8. An aerosol product according to claim 6, characterized in that, The sum of the cross-sectional areas of the through holes accounts for 50%-60% of the cross-sectional area of the aerosol generating matrix. The shape of each through hole is the same as its cross-sectional area, and the cross-sectional shape is either a circle or a regular polygon. The area of a single through hole accounts for 3%-60% of the area of the aerosol generating matrix.
9. An aerosol product according to claim 6, characterized in that, All the pores are distributed in an axisymmetric and / or centrosymmetric manner with respect to the center of the aerosol generating matrix.
10. An aerosol product according to claim 9, characterized in that, All the aforementioned through holes are both centrally symmetric and axisymmetric, and the number of axisymmetric axes is greater than one.
11. An aerosol product according to claim 6, characterized in that, There is a spacer wall between adjacent through holes, and the spacer walls have the same thickness.
12. An aerosol product according to claim 1, characterized in that, The aerosol generating matrix has micropores, and the average cross-sectional area of the micropores in any cross-section of the aerosol generating matrix is 800 μm. 2 -1200μm 2 between.
13. An aerosol product according to claim 2, characterized in that, The aerosol product includes an aerosol generating matrix, a filter section, a cavity section, and an outer coating layer; the aerosol generating matrix, the cavity section, and the filter section are arranged sequentially along the axial direction of the aerosol product; the outer coating layer completely covers the aerosol generating matrix, the cavity section, and the filter section.
14. An aerosol product according to claims 1-12, characterized in that, Both the aerosol generating matrix and the functional segment are columnar structures with the same outer diameter and are coaxially arranged, with a circular or polygonal cross-section.