Cooling filtering material and cigarette filter tip

Abstract

The invention relates to the technical field of cigarette filters, in particular to a cooling filter material and a cigarette filter. The cooling filtering material comprises a plurality of fiber units which are arranged in parallel to form a bundle, and a circulation cavity is formed between every two adjacent fiber units; each fiber unit comprises a cooling filament, and each cooling filament comprises a core layer and a cooling coating wrapping the core layer; the fiber unit further comprises filtering wires spirally wound on the cooling wires, and the surface of the cooling coating comprises filtering parts covered by the filtering wires and cooling parts located between every two adjacent filtering parts. According to the fiber unit, a circumferential compounding mode that the filtering wires are spirally wound on the cooling wires is adopted, so that the compounding length is reduced while the cooling and filtering effects are achieved, and in addition, suction resistance can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of cigarette filters, in particular to a cooling filter material and a cigarette filter, and in particular to a cooling filter material and a cigar filter. Background Art

[0002] Cigars are one of the important varieties of tobacco products, and the third largest tobacco product after flue-cured tobacco and blended cigarettes. As a high-end tobacco product, cigars are loved by consumers for their unique smoking experience and rich taste. However, after the middle and late stages of smoking, due to the high temperature of the smoke, it may not only affect the original flavor of the cigar, but also cause discomfort to the smoker's mouth and respiratory tract, affecting the tasting experience.

[0003] Although there is a slight difference in the burning temperature between cigars and ordinary cigarettes, the current cooling methods for cigars are still basically the same as those for ordinary cigarettes, and some of the methods are to achieve cooling by externally connecting a filter tip and setting a cooling material in the filter tip. For example, the patent document with publication number CN111602845A discloses a cigarette cooling gel particle and its application, wherein the cigarette filter rod includes two filter segments and a hollow cooling segment sandwiched between the two filter segments, and the cigarette cooling gel particle is added to the hollow cooling segment. Another example is a heat-not-burn cigarette mouthpiece and a heat-not-burn cigarette disclosed in the patent document with publication number CN108903056A: the heat-not-burn cigarette mouthpiece includes a diversion and cooling section and a filtering section, the diversion and cooling section includes tobacco leaves, and the tobacco leaves are used to cool and guide the smoke passing through the diversion and cooling section; the first end of the filtering section is connected to the diversion and cooling section, and is used to receive the smoke cooled by the diversion and cooling section and transfer the smoke to the end of the cigarette mouthpiece away from the diversion and cooling section, and the surface of the tobacco leaves is coated with a material having a phase change function and / or a moisturizing function. The material includes propylene glycol, glycerol, sorbitol, oligomaltitol or a thermotropic phase change gel.

[0004] It can be seen that in the prior art, whether the cooling material is used alone or coated on certain carriers, if the filter tip is to achieve technical effects such as filtering and cooling at the same time, it is always necessary to compound the filtering section and the cooling section in the axial direction, which will cause the filter tip to be long and inconvenient to use and carry; and if the length of the filter tip is reduced, it will cause problems such as insufficient filtering effect and insufficient cooling effect. Summary of the invention

[0005] The present invention aims to solve the above problems and provides a cooling filter material and a cigarette filter made of the cooling filter material which is relatively short and convenient to use and carry while still having good cooling and filtering effects.

[0006] The technical solution of the present invention to solve the problem is: first , provides a cooling filter material, including a plurality of fiber units, wherein the plurality of fiber units are arranged in a bundle, and a flow cavity is formed between adjacent fiber units; the fiber unit includes a cooling wire, wherein the cooling wire includes a core layer and a cooling coating layer coated on the outside of the core layer; the fiber unit also includes a filter wire spirally wound on the cooling wire, and the surface of the cooling coating layer includes a filter portion covered by the filter wire, and a cooling portion located between two adjacent filter portions.

[0007] In the present application, firstly, the material is bundled with a number of fiber units, each of which includes cooling filaments and filtering filaments to have cooling and filtering effects. The cooling and filtering effects of the material bundled with a large number of fiber units are more significant.

[0008] Second, in each fiber unit, a coating for cooling is provided on the surface of the cooling wire, so that the area of ​​the cooling coating that the smoke can contact is large, thereby improving the cooling effect; the filter wire is spirally shaped, so that the area of ​​the filter wire that the smoke can contact is large, thereby improving the filtering effect.

[0009] Third, the filter wire is spirally wound on the cooling wire. On the one hand, the surface of the fiber unit functionally includes an alternating filter part and a cooling part. When the smoke flows along the spiral of the filter wire, it can be filtered by the filter wire and cooled by the cooling coating of the cooling part, so as to achieve the effect of cooling and filtering simultaneously. On the other hand, the surface of the fiber unit structurally includes a relatively protruding part (filter wire surface) and a relatively concave part (cooling wire surface). The protruding part is used to abut against the adjacent fiber unit, so that a cavity is formed between the concave part and the adjacent fiber unit for smoke circulation, thereby reducing the suction resistance of the material. In addition, since the filter wire and the cooling wire are compounded in the circumferential direction, the length of the fiber unit is shorter than that of the filter wire and the cooling wire in the axial direction, and a relatively short filter tip can be made therefrom, which is convenient for use and carrying.

[0010] Based on this, the present application provides a cooling filter material that has good cooling and filtering effects without increasing the axial length, and also has the characteristics of low absorption resistance.

[0011] In the structure of cooling filter material In some embodiments, in order to further improve the synchronous cooling and filtering effect, as a preferred embodiment of the present invention, the filter wire of one fiber unit abuts against the cooling portion of the adjacent fiber unit, so that when the smoke flows along the spiral filter wire of a fiber unit, it can contact the cooling portion of the adjacent fiber unit to achieve further cooling.

[0012] The method for forming the above structure is not limited. As a preferred embodiment of the present invention, the pitch of the spiral winding of the filter wire is controlled to be larger than the outer diameter of the filter wire. The ends of several fiber units are aligned and directly merged to make most of the fiber units in the material meet the above structure without special alignment.

[0013] In the selection of cooling filter materials, for cooling wire, cooling coating In order to play a major part in the cooling effect, the material used in the cooling coating can be any commonly used cooling material in the prior art, such as aerogel, hydrogel, phase change material, etc.

[0014] In some embodiments, in order to further improve the cooling effect, as a preferred embodiment of the present invention, the cooling coating includes a hydrogel. The hydrogel material is a highly absorbent polymer that can quickly absorb and lock a large amount of water. The hydrogel material after absorbing water and swelling has good thermal conductivity and water retention, and can effectively reduce the temperature of the smoke passing through it.

[0015] The choice of hydrogel is not limited, for example, polyacrylamide-sodium acrylate hydrogel, polyvinyl alcohol hydrogel, sodium alginate hydrogel, cellulose hydrogel, etc. commonly used in the prior art can be used.

[0016] In some embodiments, in order to further improve the cooling effect of the material, as a preferred embodiment of the present invention, the gel layer includes a heat-shrinkable thermosensitive hydrogel. A heat-shrinkable thermosensitive hydrogel refers to a gel whose volume can shrink as the temperature rises. Specifically, when the temperature rises, the water molecules of the gel detach from the polymer chain due to the mutual attraction of the hydrophobic groups, and the gel volume shrinks. When it is used in a cigarette filter, the water molecules detach when encountering high-temperature flue gas, and the detached water molecules mix with the flue gas to further improve the cooling effect. In addition, due to the shrinkage of the gel volume, the outer diameter of the cooling wire is reduced, thereby increasing the distance between adjacent fiber units to allow smoke to circulate, which can improve the suction resistance during the suction process. Moreover, for some filter wires that may have hot melting problems, the cooling wire with a reduced outer diameter can reduce the adhesion and clogging problems between the filter wire and the adjacent fiber units.

[0017] The selection of heat-shrinkable thermosensitive hydrogel is not limited. As a preferred embodiment of the present invention, at least one of poly (N-isopropylacrylamide) hydrogel, poly (N-isopropylacrylamide) / polyacrylic acid hydrogel, and polyvinyl acetamide / polyvinyl ester hydrogel can be selected.

[0018] The core layer in the cooling wire It mainly plays the role of loading the cooling coating. The choice of the core layer is not restricted. The fibers commonly used in cigarette filters in the prior art can be selected, such as polypropylene fibers, polylactic acid fibers, acetate fibers, diacetate fibers, polyester fibers, carbon fibers, etc.

[0019] In the embodiment using hydrogel, the core layer is preferably made of water-absorbing or non-absorbent material to ensure that the moisture in the hydrogel combines with the smoke to reduce the temperature. As a preferred embodiment of the present invention, the core layer is selected from at least one of polypropylene fiber, polyester fiber, and carbon fiber.

[0020] The outer diameter of the core layer is not limited, and the core layer can be a thin single filament or a thick filament bundled with several thin single filaments. In the laboratory stage, thick filaments can be used; in the mass production stage, thin single filaments can be used.

[0021] Preparation method of cooling wire Without limitation, in the embodiment where the temperature-cooling coating adopts phase change material, the phase change material can be heated and melted and then applied to the core layer by brush or co-roll coating; or the core layer can be taken out after being immersed in the hot melt of the phase change material for a period of time.

[0022] In the embodiment where the cooling coating uses gel, the core layer can be immersed in a precursor solution composed of gel monomer, crosslinking agent, initiator and solvent, and then the precursor polymerization reaction is initiated; or an adhesive and gel can be coated on the core layer in sequence.

[0023] The ratio of the core layer to the cooling coating should be limited. Too much cooling coating may cause the cooling coating to fall off the core layer and block the flow cavity; too little cooling coating may result in poor cooling effect. As a preferred embodiment of the present invention, the coating ratio of the cooling coating on the core layer is 0.1-1 g / cm 2 , that is, the surface area is 1 cm 2 0.1-1g of cooling coating can be coated on the core layer, specifically 0.1g, 0.2g, 0.3g, 0.4g, 0.5g, 0.6g, 0.7g, 0.8g, 0.9g, 1g, preferably 0.5g.

[0024] For filter wire The filter thread is the same as the traditional cigarette filter and plays a filtering role through adsorption. Therefore, the selection of the filter thread is basically the same as the material used for the traditional cigarette filter. As a preferred embodiment of the present invention, the filter thread is selected from at least one of polylactic acid fiber, acetate fiber, diacetate fiber, and polypropylene fiber.

[0025] The outer diameter of the filter wire is not limited. In some embodiments, in order to further improve the draw resistance, as a preferred embodiment of the present invention, the outer diameter of the filter wire is not less than half of the outer diameter of the cooling wire. A thicker filter wire allows a larger distance between adjacent fiber units to allow smoke to flow more smoothly.

[0026] Preparation method of fiber unit There is no restriction. In the laboratory stage, thicker cooling wire and filtering wire can be used and wound by oneself.

[0027] In the mass production stage, thinner cooling yarn and filter yarn can be used. At this time, the molding process of the coated yarn in the prior art can be referred to. For example, a coated yarn machine is used to parallel the cooling yarn into the hollow spindle after passing through the drafting device, and the filter yarn cylinder is sleeved on the hollow spindle and rotated together. The filter yarn is also fed into the hollow spindle when unwinding, and moves downward under the action of the suction pipe. As the filter yarn cylinder rotates, the filter yarn wraps a twist around the cooling yarn every time it rotates, forming a fiber unit. Among them, the pitch of the spiral winding is controlled by controlling the drafting speed of the cooling yarn or the rotation speed of the filter yarn cylinder.

[0028] Secondly Another object of the present invention is to provide a cigarette filter, comprising a shell provided with a cigarette interface and a suction port, and the above-mentioned cooling filter material, wherein the cooling filter material is filled in the shell, and the direction from the cigarette interface to the suction port is parallel to the length direction of the cooling filter material.

[0029] In the cigarette filter of the present application, only one material needs to be filled between the cigarette interface and the suction port to achieve better cooling and filtering effects at the same time.

[0030] As a preferred embodiment of the present invention, the housing includes an interface sub-shell, a filling sub-shell, and a suction port sub-shell in sequence along the axial direction, the interface sub-shell and the filling sub-shell are detachably connected via a threaded structure, and the filling sub-shell and the suction port sub-shell are detachably connected via a threaded structure. The detachable connection facilitates the replacement of the interface sub-shell to be suitable for ordinary cigarettes or cigars; it also facilitates the replacement of the cooling filter material in the filling sub-shell.

[0031] In the embodiment using hydrogel, since the hydrogel will lose water after a period of use, affecting the subsequent cooling effect, it is necessary to replenish water to the hydrogel. As a preferred embodiment of the present invention, the shell includes a filling part for filling the cooling filter material, and a liquid replenishing part for replenishing liquid for the cooling coating in the cooling filter material, and a liquid bag is provided in the liquid replenishing part, and a liquid guide is provided between the liquid bag and the cooling filter material. The liquid bag can be filled with deionized water, tobacco flavors, etc., and filling with tobacco flavors can further improve the sensory experience of smoking.

[0032] In order to improve the uniformity of the fluid replenishment, as a preferred embodiment of the present invention, the shell includes an inner shell and an outer shell, the filling part is formed in the inner shell, and the fluid replenishment part is formed between the inner shell and the outer shell.

[0033] Beneficial effects of the present invention: 1. The present application provides a cooling filter material, which is composed of a plurality of fiber units. The fiber units are circumferentially composited in a spirally wound manner on a cooling wire to achieve cooling and filtering effects while reducing the composite length, and also improve the suction resistance.

[0034] 2. The present application provides a cigarette filter made using the above-mentioned cooling filter material, which is relatively short and convenient to use and carry, while still having good cooling and filtering effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a partial structural schematic diagram of the cooling filter material in Example 1; Figure 2 is a schematic diagram of the structure of the cigarette filter in Examples 7 and 8; Figure 3 is a schematic diagram of disassembling the cigarette filter in Examples 7 and 8; In the figure: fiber unit 1, cooling wire 11, core layer 111, cooling coating 112, filter part 112a, cooling part 112b, filter wire 12, flow cavity 2, shell 3, smoke interface 31, suction port 32, filling part 3a, liquid replenishing part 3b. DETAILED DESCRIPTION

[0036] The following are specific embodiments of the present invention, and further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0037] Example 1 A cooling filter material, such as Figure 1 As shown, it includes a plurality of fiber units 1, which are arranged in a bundle, and a flow cavity 2 is formed between adjacent fiber units 1. The fiber unit 1 includes a cooling wire 11, and the cooling wire 11 includes a core layer 111 and a cooling coating 112 coated on the outside of the core layer 111; the fiber unit 1 also includes a filter wire 12 spirally wound on the cooling wire 11, and the surface of the cooling coating 112 of the cooling wire 11 includes a filter part 112a covered by the filter wire 12, and a cooling part 112b located between two adjacent filter parts 112a. At the same time, part of the filter wire 12 of the fiber unit 1 corresponds to the cooling part 112b of the adjacent fiber unit 1.

[0038] In this embodiment, the core layer 111 is made of polypropylene fiber; the cooling coating 112 is made of a phase change material composed of Na2HPO4·12H2O, urea, and CaSO4·2H2O; and the filter filament 12 is made of acetate fiber.

[0039] The cooling filter material is prepared by the following steps: Cooling yarn: prepare polypropylene fibers, and bundle several polypropylene fibers into coarse polypropylene fibers with an outer diameter of 0.5 mm. Mix Na2HPO4·12H2O, urea, and CaSO4·2H2O in a mass ratio of 8:3:1 and melt them at 60°C to obtain a mixed system, and keep the mixture in a heated molten state. Control the coarse polypropylene fibers to pass through the mixed system at a speed of 0.05 m / s, and then send them into an air cooling device for cooling and crystallization to obtain cooling yarns. The amount of cooling coating coated on the coarse polyacrylic acid fiber can be obtained by weighing the mass of the mixed system before and after use and calculating the mass difference. In this embodiment, the coarse polypropylene fiber with a total length of 12 m (surface area of ​​2.355 cm 2 ) 1.2g of cooling coating was used.

[0040] Filter filaments: Prepare acetate fibers and bundle several acetate fibers into coarse acetate fibers with an outer diameter of 0.5 mm.

[0041] Fiber unit: The filter wire is spirally wound on the cooling wire with a spiral pitch of 2mm, and then cut to a length of 30mm per wire.

[0042] Cooling filter material: 400 fiber units are combined together and filled into a cylindrical tube with an inner diameter of 20 mm to obtain a cooling filter material.

[0043] Example 2 This embodiment is basically the same as the embodiment 1, and the only difference is that the cooling coating uses polyvinyl alcohol / sodium alginate hydrogel.

[0044] The cooling filter material is prepared by the following steps: Cooling yarn: Prepare polypropylene fibers, bundle several polypropylene fibers into a coarse polypropylene fiber with an outer diameter of 0.5 mm and a length of 12 m. Dissolve 0.8 g polyvinyl alcohol and 0.4 g sodium alginate in 30 g deionized water, stir evenly at 95 ° C to obtain a transparent solution. Place the coarse polypropylene fiber evenly in the transparent solution, freeze it at -20 ° C for 24 hours, thaw it at room temperature for 2 hours, and repeat this freezing-thawing process 3 times to obtain cooling yarn.

[0045] Filter filaments: Prepare acetate fibers and bundle several acetate fibers into coarse acetate fibers with an outer diameter of 0.5 mm.

[0046] Fiber unit: The filter wire is spirally wound on the cooling wire with a spiral pitch of 2mm, and then cut to a length of 30mm per wire.

[0047] Cooling filter material: 400 fiber units are combined together and filled into a cylindrical tube with an inner diameter of 20 mm to obtain a cooling filter material.

[0048] Example 3 This embodiment is basically the same as Embodiment 1, and the only difference is that the cooling coating uses poly (N-isopropylacrylamide) hydrogel.

[0049] The cooling filter material is prepared by the following steps: Cooling yarn: Prepare polypropylene fibers, and bundle several polypropylene fibers into a crude polypropylene fiber with an outer diameter of 0.5 mm and a length of 12 m. Add 1.2 g of N-isopropyl acrylamide, 0.05 g of ammonium persulfate as an initiator, and 0.06 g of N,N'methylenebisacrylamide as a cross-linking agent to 30 g of deionized water to obtain a precursor solution. Immerse the crude polypropylene fiber in the precursor solution, mix and stir until there are no bubbles, and seal to obtain a mixed system. Place the mixed system in a 60°C constant temperature water bath for reaction for 3 hours, then take out the solid matter to obtain the cooling yarn.

[0050] Filter filaments: Prepare acetate fibers and bundle several acetate fibers into coarse acetate fibers with an outer diameter of 0.5 mm.

[0051] Fiber unit: The filter wire is spirally wound on the cooling wire with a spiral pitch of 2mm, and then cut to a length of 30mm per wire.

[0052] Cooling filter material: 400 fiber units are combined together and filled into a cylindrical tube with an inner diameter of 20 mm to obtain a cooling filter material.

[0053] Example 4 This embodiment is basically the same as Embodiment 3, and the only difference is that the preparation method of the cooling wire is different.

[0054] The cooling filter material is prepared by the following steps: Cooling silk: prepare polypropylene fibers, and bundle several polypropylene fibers into coarse polypropylene fibers with an outer diameter of 0.5 mm and a length of 12 m. Add 1.2 g of N-isopropyl acrylamide, 0.05 g of ammonium persulfate as an initiator, and 0.06 g of N,N'methylenebisacrylamide as a cross-linking agent to 5 g of deionized water to obtain a precursor solution. After the precursor solution is placed in a 60°C constant temperature water bath for reaction for 3 hours, the solid is taken out to obtain a hydrogel. At 25°C, the hydrogel is placed in deionized water to absorb water to obtain a transparent sol. The coarse polypropylene fiber is immersed in the sol to obtain a mixed system. The mixed system is then heated to 40°C, and the hydrogel is drained and condensed to obtain cooling silk. In this embodiment, since the hydrogel is drained during the preparation process, it is necessary to replenish the liquid through the liquid bag when it is used as a cigarette filter later.

[0055] Filter filaments: Prepare acetate fibers and bundle several acetate fibers into coarse acetate fibers with an outer diameter of 0.5 mm.

[0056] Fiber unit: The filter wire is spirally wound on the cooling wire with a spiral pitch of 2mm, and then cut to a length of 30mm per wire.

[0057] Cooling filter material: 400 fiber units are combined together and filled into a cylindrical tube with an inner diameter of 20 mm to obtain a cooling filter material.

[0058] Example 5 This embodiment is basically the same as Embodiment 3, and the only difference is that the outer diameters of the cooling wire and the filter wire are different.

[0059] The cooling filter material is prepared by the following steps: Cooling yarn: Prepare polypropylene fibers, and bundle several polypropylene fibers into a crude polypropylene fiber with an outer diameter of 0.1 mm and a length of 300 m. Add 1.2 g of N-isopropyl acrylamide, 0.05 g of ammonium persulfate as an initiator, and 0.06 g of N,N'methylenebisacrylamide as a cross-linking agent to 30 g of deionized water to obtain a precursor solution. Immerse the crude polypropylene fiber in the precursor solution, mix and stir until there are no bubbles, and seal to obtain a mixed system. Place the mixed system in a 60°C constant temperature water bath for reaction for 3 hours, then take out the solid matter to obtain the cooling yarn.

[0060] Filter filaments: Prepare acetate fibers and bundle several acetate fibers into coarse acetate fibers with an outer diameter of 0.1 mm.

[0061] Fiber unit: The filter wire and the cooling wire are sent to the textile factory, and the filter wire is spirally wound on the cooling wire using a covering yarn machine, with a spiral pitch of 0.4mm, and then cut into 30mm lengths.

[0062] Cooling filter material: 10,000 fiber units are combined together and filled into a cylindrical tube with an inner diameter of 20 mm to obtain a cooling filter material.

[0063] Example 6 This embodiment is basically the same as Embodiment 3, the only difference being that the core layer is made of polylactic acid fiber.

[0064] The cooling filter material is prepared by the following steps: Cooling yarn: Prepare polylactic acid fibers, and bundle several polylactic acid fibers into coarse polylactic acid fibers with an outer diameter of 0.5 mm and a length of 12 m. Add 1.2 g of N-isopropyl acrylamide, 0.05 g of ammonium persulfate as an initiator, and 0.06 g of N,N'methylenebisacrylamide as a cross-linking agent to 30 g of deionized water to obtain a precursor solution. Immerse the coarse polylactic acid fibers in the precursor solution, mix and stir until there are no bubbles, and seal to obtain a mixed system. Place the mixed system in a constant temperature water bath at 60°C for reaction for 3 hours, then take out the solid matter to obtain the cooling yarn.

[0065] Filter filaments: Prepare acetate fibers and bundle several acetate fibers into coarse acetate fibers with an outer diameter of 0.5 mm.

[0066] Fiber unit: The filter wire is spirally wound on the cooling wire with a spiral pitch of 2mm, and then cut to a length of 30mm per wire.

[0067] Cooling filter material: 400 fiber units are combined together and filled into a cylindrical tube with an inner diameter of 20 mm to obtain a cooling filter material.

[0068] Example 7 A cigarette filter comprises the cylindrical tube filled with a cooling filter material prepared in Example 1.

[0069] like Figure 2 and Figure 3 As shown, the cigarette filter comprises a housing 3, which comprises an interface sub-shell, a filling sub-shell, and a suction port sub-shell in sequence along the axial direction. One end of the interface sub-shell forms a cigarette interface 31, and the other end is connected to the filling sub-shell through a threaded structure. One end of the suction port sub-shell forms a suction port 32, and the other end is connected to the filling sub-shell through a threaded structure. The interface sub-shell, the filling sub-shell, and the suction port sub-shell are sequentially connected to allow smoke to flow from the cigarette interface 31 to the suction port 32.

[0070] The cooling filter material prepared in Example 1 is filled in the filling sub-shell, specifically: the two ends of the cylindrical tube filled with cooling filter material prepared in Example 1 are closed by stop plates respectively, and a number of through holes are opened on the stop plates for smoke circulation. During installation, the filling sub-shell is first threadedly connected with the interface sub-shell; then the cylindrical tube is inserted into the filling sub-shell, and the axial direction of the cylindrical tube is parallel to the axial direction of the shell 3; finally, the suction port sub-shell is threadedly connected with the filling sub-shell. Since the length direction of the fiber unit 1 is parallel to the axial direction of the cylindrical tube during the above filling, the length direction of the fiber unit 1 is parallel to the axial direction of the shell 3, that is, parallel to the axial direction of the smoke interface 31 to the suction port 32.

[0071] When in use, insert an ordinary cigarette or cigar into the cigarette interface 31 of the interface sub-shell, and after lighting the cigarette, the smoke enters the interface sub-shell, enters the cooling filter material through the through hole of the stop plate, is cooled and filtered at the cooling filter material, and then flows out from the through hole of the stop plate at the other end to the suction port sub-shell, and then is inhaled by the user through the suction port 32.

[0072] Example 8 This embodiment is basically the same as Embodiment 7, and the only difference is that: First, the cylindrical tube filled with the cooling filter material prepared in Example 4 was used.

[0073] Second, if Figure 2 and Figure 3 As shown, the filling subshell includes a cylindrical part (i.e., the outer shell) and two stop rings arranged in the cylindrical part. When the cylindrical tube (i.e., the inner shell) in Example 4 is inserted into the filling subshell, based on the stopping of the stop ring, an annular cavity is formed between the filling subshell, the two stop rings and the outer wall of the cylindrical tube, which is the liquid replenishing part 3b. At the same time, an opening and a cover body for covering the opening are provided on the filling subshell, which is used to add a liquid bag into the liquid replenishing part 3b. The inside of the cylindrical tube is the filling part 3a for filling the cooling filter material.

[0074] In order to guide the liquid in the liquid bag into the cooling filter material, a liquid guide 33 is provided between the liquid bag and the cooling filter material. Specifically, the liquid guide 33 is a pipe with openings at both ends, and a plurality of openings are provided on the pipe body of the pipe along the length direction; at the same time, a through hole is provided on the cylindrical tube. During installation, the filling subshell is first threadedly connected with the interface subshell; then the cylindrical tube is inserted into the filling subshell, and the cover of the filling subshell is opened, and one end of the pipe is inserted into the cooling filter material through the through hole of the cylindrical tube, and the other end is left in the liquid replenishing part 3b; then the suction port subshell is threadedly connected with the filling subshell; finally, the liquid bag is placed in the liquid replenishing part 3b, and the cover of the filling subshell is closed, and the liquid bag is pressed by the cover to make the end of the pipe close to the contact, so that it is punctured by the pipe, and the liquid in the liquid bag can flow along the pipe to the cooling filter material.

[0075] Example 9 This embodiment is basically the same as the embodiment 7, and the only difference is that the cylindrical tube filled with the cooling filter material prepared in the embodiment 2 is used.

[0076] Example 10 This embodiment is basically the same as the embodiment 7, and the only difference is that the cylindrical tube filled with the cooling filter material prepared in the embodiment 3 is used.

[0077] Embodiment 11 This embodiment is basically the same as the embodiment 7, and the only difference is that the cylindrical tube filled with the cooling filter material prepared in the embodiment 5 is used.

[0078] Example 12 This embodiment is basically the same as the embodiment 7, and the only difference is that the cylindrical tube filled with the cooling filter material prepared in the embodiment 6 is used.

[0079] Blank example The blank example is substantially the same as Example 7, the only difference being that an empty cylindrical tube is inserted into the filling shell.

[0080] Comparative Example 1 Comparative Example 1 is substantially the same as Example 7, except that the following materials are inserted into the filling shell: This material is prepared by the following steps: take the cooling wire and filter wire prepared in Example 1, cut the cooling wire and filter wire into a length of 30 mm each, and directly combine 400 filter wires and 400 cooling wires into a bundle, and then fill them into a cylindrical tube with an inner diameter of 20 mm to obtain the material.

[0081] Comparative Example 2 Comparative Example 1 is substantially the same as Example 7, except that the following materials are inserted into the filling shell: This material is prepared by the following steps: take the cooling wire and filter wire prepared in Example 1, cut the cooling wire and filter wire into a length of 30 mm each, combine 400 filter wires into a bundle, and fill them into a first cylindrical tube with an inner diameter of 5 mm; combine 400 cooling wires into a bundle, and fill them into a second cylindrical tube with an inner diameter of 5 mm; insert the first cylindrical tube and the second cylindrical tube into the filling shell in sequence.

[0082] Performance Testing The cigarette filters obtained in Examples 7, 9-12, blank examples and comparative examples 1-2 were subjected to pressure drop testing according to GB / T 22838.5-2009 Determination of physical properties of cigarettes and filter rods Part 5: Cigarette draw resistance and filter rod pressure drop. The test results are shown in Table 1 below.

[0083] The cigarette filters obtained in Examples 7, 9-12, blank examples and comparative examples 1-2 were loaded with cigars from the same batch and then subjected to cooling and filtration tests: Cooling test: The temperature of the filter cigarette interface and the suction port are tested respectively, and the temperature difference is calculated. The calculation results are shown in Table 1 below.

[0084] Filtration test: Install the Cambridge filter at the suction port, test the quality of the Cambridge filter before and after suction, and calculate the quality difference. The results are shown in Table 1.

[0085] Table 1. As shown in Table 1, the greater the temperature difference between the cigarette interface and the suction port, the better the cooling effect; the greater the mass difference of the Cambridge filter before and after suction at the suction port, the more total particulate matter is not filtered and the worse the filtering effect; the greater the pressure drop between the filter cigarette interface and the suction port, the greater the inhalation resistance.

[0086] It can be seen from the comparison of Example 7 and Comparative Examples 1 to 2 that the present application has good cooling effect, filtering effect and low inhalation resistance. This may be because compared with Comparative Example 1, the present application spirally winds the filter wire around the cooling wire, increases the smoke flow path, and increases the time that the smoke is in contact with the filter wire and the cooling wire, so the cooling effect and filtering effect are better; at the same time, the spiral winding makes the fiber unit surface present a concave-convex structure. Compared with the smooth surface of Comparative Example 1, the protruding filter wire of the present application plays a supporting role between adjacent fiber units, preventing the flow cavity from collapsing, so as to allow the smoke to flow smoothly, and thus also provides a low inhalation resistance effect. In Comparative Example 2, since the cooling wire and the filter wire are compounded in the axial direction, the smoke flow path is longer, so that the cooling effect and filtering effect are better than the present application, but the inhalation resistance is also increased due to the longer path, and its longer structure makes it inconvenient to use and carry.

[0087] In addition, it is found through comparison in the embodiments that the selection of the cooling coating also has a certain influence on cooling, filtration, and draw resistance. By comparing Example 7 and Example 9, it can be seen that the use of hydrogel can further improve the cooling effect and the filtration effect, which may be related to the fact that the moisture in the hydrogel can assist in cooling, and the through holes of the hydrogel itself can assist in filtration. By comparing Example 9 and Example 10, it can be seen that compared with ordinary hydrogel, the heat-shrinkable thermosensitive hydrogel can further improve the cooling effect, the filtration effect, and improve the draw resistance. This may be because the heat-shrinkable thermosensitive hydrogel is more likely to release moisture when heated, and at the same time, it has more through holes after releasing more moisture, thereby improving the cooling effect and the filtration effect; and the volume of the heat-shrinkable thermosensitive hydrogel will decrease after releasing moisture, so that the distance between adjacent fiber units increases, making it easier for smoke to pass through, thereby further improving the draw resistance.

[0088] By comparing Example 10 and Example 11, it is found that the outer diameters of the filter filaments and the cooling filaments also have a certain influence on cooling, filtration, and draw resistance. In Example 11, reducing the outer diameters of the filter filaments and the cooling filaments can further improve the cooling effect and the filtration effect. This may be because the thinner and more fiber units provide a larger number of flow cavities, which can further disperse the smoke for cooling and filtration; but it also makes the flow cavity narrower, which may cause an increase in draw resistance.

[0089] By comparing Example 10 and Example 12, it is found that the choice of the core layer also has a certain influence on cooling and filtration. In Example 12, the core layer uses polylactic acid with relatively high water absorption, which affects the contact between water in the hydrogel and smoke, resulting in a reduced cooling effect; however, polylactic acid has more advantages in filtration than polypropylene, so the filtration effect is better; in addition, although polylactic acid usually has the problem of hot melt clogging affecting the suction resistance, in this application, polylactic acid is only used as the core layer, so it has little effect on the suction resistance.

[0090] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A cooling filter material, characterized in that: It comprises a plurality of fiber units (1), wherein the plurality of fiber units (1) are arranged in parallel in a bundle, and a flow cavity (2) is formed between adjacent fiber units (1); The fiber unit (1) comprises a cooling wire (11), wherein the cooling wire (11) comprises a core layer (111) and a cooling coating (112) coated outside the core layer (111); The fiber unit (1) further comprises a filter thread (12) spirally wound on the cooling thread (11), and the surface of the cooling coating (112) comprises a filter portion (112a) covered by the filter thread (12), and a cooling portion (112b) located between two adjacent filter portions (112a).

2. A cooling filter material according to claim 1, characterized in that: The filter thread (12) of one of the fiber units (1) abuts against the cooling portion (112b) of an adjacent fiber unit (1).

3. The cooling filter material according to claim 1, characterized in that: The temperature-reducing coating (112) comprises a hydrogel.

4. A cooling filter material according to claim 3, characterized in that: The hydrogel includes a heat-shrinkable temperature-sensitive hydrogel.

5. A cooling filter material according to claim 4, characterized in that: The heat-shrinkable temperature-sensitive hydrogel is selected from at least one of poly (N-isopropylacrylamide) hydrogel, poly (N-isopropylacrylamide) / polyacrylic acid hydrogel, and polyvinyl acetamide / polyvinyl acetate hydrogel.

6. The cooling filter material according to claim 3, characterized in that: The core layer (111) is selected from at least one of polypropylene fiber, polyester fiber, and carbon fiber.

7. The cooling filter material according to claim 1, characterized in that: The filter fiber (12) is selected from at least one of polylactic acid fiber, acetate fiber, diacetate fiber, and polypropylene fiber.

8. A cigarette filter, comprising a housing (3) provided with a cigarette interface (31) and a suction port (32), characterized in that: It also comprises a cooling filter material as claimed in any one of claims 1 to 7, wherein the cooling filter material is filled in the shell (3), and the direction from the smoke interface (31) to the suction port (32) is parallel to the length direction of the cooling filter material.

9. A cigarette filter according to claim 8, characterized in that: The shell (3) comprises a filling portion (3a) for filling the cooling filter material, and a liquid replenishing portion (3b) for replenishing liquid for the cooling coating (112) in the cooling filter material, wherein a liquid bag is provided in the liquid replenishing portion (3b), and a liquid guide (33) is provided between the liquid bag and the cooling filter material.

10. A cigarette filter according to claim 9, characterized in that: The shell (3) comprises an inner shell and an outer shell, the filling portion (3a) is formed in the inner shell, and the liquid replenishing portion (3b) is formed between the inner shell and the outer shell.

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