Filter cigarette holder, preparation method thereof and cigarette

Abstract

The invention relates to the field of tobacco products, in particular to a filter cigarette holder, a preparation method thereof and a cigarette. The preparation method of the filter cigarette holder comprises the following steps: step A, preparing a bearing piece; step B, preparing a sheet-shaped nanofiber membrane; and step C, adhering and fixing the nanofiber membrane at one end or two ends of the bearing piece. According to the filter tip, the nanofiber filter layer can filter out harmful substances such as tar and fine particulate matter which are difficult to filter out by a traditional filter tip such as a cellulose acetate fiber rod, and the filter efficiency is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tobacco products, in particular to a filter cigarette holder and a preparation method thereof, and a cigarette. BACKGROUND

[0002] In order to reduce the harm caused by tobacco tar, the tail of a cigarette is usually a filter cigarette rod composed of polymer fiber bundles to filter smoke and adsorb harmful components such as tar. However, the diameter of the commonly used acetate fiber bundles is more than 10 microns, which can trap tar particles through a fiber grid, mainly for particles above PM1, and the filtering efficiency for submicron smoke particles is poor. With the development of society and the improvement of people's health awareness, more and more smokers will choose to use a filter cigarette holder to purify the inhaled smoke. However, the filter cigarette holder inevitably reduces the flavor and nicotine content of the cigarette, and has problems such as increased suction resistance. The minimum filtering precision of the microporous filter used in the cigarette filter is 1 micron, and the filtering effect is still limited.

[0003] In the process of implementing the present application, the applicant found that the above-mentioned prior art has the following technical defects:

[0004] ① The filtering efficiency of traditional filter materials (such as ordinary fiber filters) for harmful substances in smoke (such as tar, fine particulate matter, etc.) is low. Currently available physical filtering methods for reducing tar, such as activated carbon filters and multiple filtering units, have poor filtering effects.

[0005] ② The existing technology of nanofiber membrane filtration does not consider the process feasibility of industrialization, and the nanofiber membrane as a filtering material will have the problem of excessive air resistance. The suction resistance will increase with the decrease of the diameter of the nanofiber and the increase of the thickness of the stack, and will also increase with the decrease of the fineness of the smoke pipe. A single solution is not suitable for all categories. SUMMARY

[0006] I. Technical problems to be solved

[0007] The present application aims to at least partially solve one of the above technical problems.

[0008] II. Technical solutions

[0009] The present application provides a filter cigarette holder preparation method. The filter cigarette holder preparation method comprises:

[0010] Step A, preparing a carrier;

[0011] Step B, preparing a sheet-shaped nanofiber membrane;

[0012] Step C, bonding and fixing the nanofiber membrane to one end or both ends of the carrier.

[0013] In some embodiments of the present application, in step A, the carrier is a filter rod; step B comprises: sub-step B1, forming a nanofiber filter layer on the spinning substrate by electrospinning; sub-step B2, forming a nanofiber adhesive layer on the nanofiber filter layer by electrospinning; wherein the spinning substrate, the nanofiber filter layer formed thereon and the nanofiber adhesive layer form an integral filter layer; in step C, the nanofiber filter layer is adhered and fixed to one end or both ends of the filter rod through the nanofiber adhesive layer.

[0014] In some embodiments of the present application, in sub-step B2, the material for preparing the nanofiber adhesive layer comprises one or more of the following: polyvinyl butyral, polyvinyl alcohol, low-melting polyester; and / or the solvent for preparing the nanofiber adhesive layer comprises one or more of the following: acetone, dimethylformamide, dimethylacetamide; and / or the solid content of the electrospinning solution for preparing the nanofiber adhesive layer is 4-20%; and / or the electrospinning parameters are as follows: voltage 10-50 kV, temperature 20-40℃, humidity 10-60 RH%, spinning distance 10-20 cm, feeding rate 0.1-3 ml / h; and / or the thickness ratio of the nanofiber adhesive layer to the nanofiber filter layer is between 1:2 and 1:50, and / or the fiber thickness of the nanofiber adhesive layer is in the range of 0.2-1 μm, and the nanofiber is in the form of a beaded structure to provide point-like adhesive sites.

[0015] In some embodiments of the present application, step C comprises: sub-step C1, arranging and fixing a plurality of filter rods in the mold, wherein each filter rod passes through a corresponding fixing hole in the mold, and the lower openings of the plurality of hollow tubes are aligned in the same plane; sub-step C2, placing the entire nanofiber membrane on a hot pressing device below the mold, the temperature of the hot pressing device being higher than the temperature at which the nanofiber adhesive layer exhibits adhesion; sub-step C3, controlling the mold to press down, so that the lower ring opening of the filter rod presses on the nanofiber adhesive layer of the nanofiber membrane, and staying for a preset time t1; sub-step C4, cutting or punching the nanofiber filter layer after adhesion with the filter rod along the lower ring opening of the filter rod, so that it is separated from the spinning substrate; or cutting or punching the nanofiber filter layer after adhesion with the filter rod together with the spinning substrate along the ring opening, so that part of the nanofiber filter layer together with the spinning substrate is separated from the other part of the entire nanofiber membrane; sub-step C5, releasing the filter rod with the adhered nanofiber filter layer from the mold.

[0016] In some embodiments of the present application, in step A, the carrier is a hollow tube; step B comprises: sub-step B1, forming a nanofiber filter layer on the spinning substrate by electrospinning; wherein the spinning substrate and the nanofiber filter layer formed thereon form an integral filter layer; step C comprises: sub-step C1', gluing the tube opening of the hollow tube; and sub-step C2', adhering and fixing the nanofiber filter layer to one side of the hollow tube with the glue.

[0017] In some embodiments of the present application, the sub-step C1' comprises: a sub-sub-step C1'a, arranging and fixing the plurality of hollow tubes from the mold, wherein each hollow tube passes through a corresponding fixed hole in the mold, and the lower tube openings of the plurality of hollow tubes are aligned in the same plane; a sub-sub-step C1'b, uniformly distributing glue in the grooves of the glue plate unit, wherein the grooves on the glue plate unit correspond to the hollow tubes in the upper mold; a sub-sub-step C1'c, controlling the mold to fall, so that the lower tube opening of each hollow tube is immersed in the glue of the corresponding groove; and a sub-sub-step C1'c, controlling the mold to rise, so that each hollow tube is separated from the glue, thereby achieving glue coating on the lower tube opening of each hollow tube.

[0018] In some embodiments of the present application, the sub-step C2' comprises: a sub-sub-step C2'a, placing the whole nanofiber membrane formed with the nanofiber filter layer on the platform below the mold; a sub-sub-step C2'b, controlling the mold to press down, so that the lower tube openings of the plurality of hollow tubes carrying glue on the mold are adhered and fixed to the nanofiber membrane, and staying for a preset time t2; a sub-sub-step C2'c, cutting or punching the nanofiber filter layer adhered to the hollow tube along the circle opening, so that the nanofiber filter layer is separated from the substrate; or cutting or punching the nanofiber filter layer adhered to the hollow tube together with the substrate along the circle opening, so that part of the nanofiber filter layer together with the substrate is separated from the other part of the whole nanofiber membrane; a sub-sub-step C2'c, releasing the hollow tube adhering the nanofiber filter layer from the mold; and / or, the step C is followed by a step D, connecting the hollow tube adhering the nanofiber filter layer to one end of the filter rod.

[0019] In some embodiments of the present application, the preset time t1 is between 5-15s; and the preset time t2 is between 5-15s.

[0020] In some embodiments of the present application, the electrospinning solution for preparing the nanofiber filter layer is a polyurethane emulsion in an aqueous system.

[0021] In some embodiments of the present application, the mold is a flat plate arranged with M rows and N columns of equidistant circular holes, the diameter of the circular hole matches the diameter of the hollow tube, and the thickness of the flat plate is less than the height of the hollow tube.

[0022] In some embodiments of the present application, and / or, the mold is moved and controlled by an upper hanging rocker arm, and the whole nanofiber membrane is moved and controlled by a lower roller, and the upper hanging rocker arm and the lower roller are controlled at the same frequency.

[0023] In some embodiments of the present application, and / or, the nanofiber filter layer comprises coarse fibers and fine fibers with different fiber diameters, wherein the diameter of the fine fiber is between 200nm-1μm, and the diameter of the coarse fiber is between 1-3μm.

[0024] In some embodiments of the present application, the sub-step B1 comprises: synchronously spinning the coarse fibers and the fine fibers on the textile substrate to form the nanofiber filter layer with the coarse fibers and the fine fibers in a disordered arrangement by adjusting the concentration, the conductivity, the spinning parameters of the electrospinning solution.

[0025] In some embodiments of the present application, the sub-step B1 comprises: first forming the coarse fiber filter layer on the textile substrate by adjusting the arrangement of the spinning needle and the concentration, the conductivity, the spinning parameters of the electrospinning solution; and then forming the fine fiber filter layer, the coarse fiber filter layer and the fine fiber filter layer together forming the nanofiber filter layer with the coarse fibers and the fine fibers in a layered arrangement.

[0026] In some embodiments of the present application, in step B, the spinning substrate is a release substrate; and in step C, the nanofiber filter layer bonded with the carrier is cut or punched along the lower ring opening of the carrier to separate the nanofiber filter layer from the release substrate.

[0027] In some embodiments of the present application, in step B, the substrate is a release-free substrate; and in step C, the nanofiber filter layer bonded with the carrier is cut or punched along the lower ring opening of the carrier together with the release-free substrate to separate the nanofiber filter layer from the release-free substrate.

[0028] The second aspect of the present application provides a filter tip. The filter tip is prepared by the filter tip preparation method described above.

[0029] The third aspect of the present application provides a cigarette. The cigarette comprises: a filter tip, which is the filter tip described above; a tobacco segment, which is arranged immediately upstream of the filter tip; and a tipping paper, which is wrapped outside the filter tip and the tobacco segment.

[0030] III. Beneficial Effects

[0031] From the above technical solutions, the present application has at least one of the following beneficial effects relative to the prior art:

[0032] ① In the present application, the nanofiber filter layer can filter out harmful substances such as tar and fine particulate matter that are difficult to filter out by traditional filter tips such as acetate fiber rods, greatly improving the filtration efficiency.

[0033] ② In some embodiments of the present application, the adhesive substance is added in the form of electrospinning, and through the spinning string bead morphology, nanometer or micrometer-sized bead-shaped adhesive points are formed on the surface of the nanofilm, effectively bonding and not blocking the pores to cause the suction resistance to decrease.

[0034] ③ In some embodiments of the present application, the nanofiber film is used as the filter layer and the adhesive layer, a new industrialized way of combining with the acetate fiber rod is designed, which can simplify the production process and improve the production efficiency.

[0035] ④ In some embodiments of the present invention, environmentally friendly cellulose-based nonwoven fabrics are used as the spinning substrate, such as bamboo fiber nonwoven fabric, polylactic acid nonwoven fabric, and viscose nonwoven fabric. In this case, in the steps of making the filter mouthpiece and the finished cigarette, it is not necessary to remove the spinning substrate; the filter mouthpiece can be directly bonded and cut to the tobacco paper stick, which reduces the requirements for cutting precision and simplifies the production steps.

[0036] ⑤ In some embodiments of the present invention, the nanofiber filter layer composed of a blend / layer of coarse and fine fibers can effectively intercept tar particles of different sizes, achieve the interception and adsorption of carcinogenic particulate matter below the micrometer level, and improve its porosity to avoid the problem of excessive suction resistance. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a cigarette containing a second embodiment of the filter mouthpiece of the present invention.

[0038] Figure 2 for Figure 1 The diagram shows the application of adhesive to the opening of the hollow paper tube in the filter mouthpiece.

[0039] Figure 3 for Figure 1 The flowchart shown is for the preparation method of the filter mouthpiece.

[0040] Figures 4A-4E for Figure 3 The diagram shows an intermediate product of the filter mouthpiece after each step of the filter mouthpiece preparation method is performed.

[0041] Figure 5 This is a schematic diagram of an embodiment in which both ends of a hollow paper tube are covered with nanofiber filter layers.

[0042] Figure 6A and Figure 6B These are electron microscope images showing the diameter distribution of fine and coarse fibers laminated in the nanofiber filter layer.

[0043] Figure 7 This is a schematic diagram of a cigarette containing a third embodiment of the filter mouthpiece of the present invention.

[0044] Figure 8 for Figure 7 The flowchart shown is for the preparation method of the filter mouthpiece.

[0045] Figures 9A-9D for Figure 8 A schematic diagram of the intermediate product of the filter mouthpiece after each step of the preparation method shown. Detailed Implementation

[0046] This invention designs a cigarette stick process based on nanofiber membrane adsorption, using nanofiber membrane as the filter material, which is beneficial to improving filtration efficiency and realizing industrial production.

[0047] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0048] The first embodiment of the filter mouthpiece of the present invention includes: a carrier, which is a cellulose acetate rod or a hollow tube; and a nanofiber membrane, which is sheet-like and bonded to one or both ends of the carrier.

[0049] The method for preparing the filter mouthpiece is characterized by comprising:

[0050] Step A: Prepare the support components;

[0051] Step B: Prepare sheet-like nanofiber membranes;

[0052] Step C: Adhere and fix the nanofiber membrane to one or both ends of the carrier.

[0053] In this embodiment, a nanofiber filter layer is used to filter harmful substances, which can remove harmful substances such as tar and fine particulate matter that are difficult to filter with traditional filter nozzles, such as cellulose acetate rods, thus greatly improving the filtration efficiency; at the same time, it also has the advantages of simple structure, low cost, and industrial production capability.

[0054] Figure 1 This is a schematic diagram of the structure of the second embodiment of the filter mouthpiece of the present invention. Figure 2 for Figure 1 The diagram shows the application of adhesive to the opening of the hollow paper tube in the filter mouthpiece. Figure 1 and Figure 2 As shown, the filter mouthpiece in this embodiment includes;

[0055] Hollow paper tube 10, as a carrier of nanofiber filter layer, has its tube opening coated with glue 11;

[0056] The nanofiber membrane 21 is sheet-like and is bonded and fixed to one end of the hollow paper tube;

[0057] Filter rod 31, a hollow tube with a nanofiber filter layer bonded to one end of the filter rod;

[0058] In this process, a tobacco segment A is fixed on the side of the nanofiber membrane 21 away from the filter rod.

[0059] Figure 3 for Figure 1 The flowchart shown is for the preparation method of the filter mouthpiece. Figures 4A-4E for Figure 3The schematic diagram of the filter cigarette after the filter cigarette manufacturing method shown in the embodiment is executed. As shown in the figure, Figure 3 The filter cigarette manufacturing method shown in the embodiment includes the following steps:

[0060] Step A, preparing a hollow paper tube;

[0061] Step B, preparing a nanofiber membrane in sheet form;

[0062] In the embodiment, step B includes: forming a nanofiber filter layer on the whole spinning base material by electrospinning; wherein the spinning base material and the nanofiber filter layer formed thereon constitute an integral filter layer.

[0063] Step C, bonding and fixing the nanofiber filter layer to one end of the hollow paper tube;

[0064] In the embodiment, step C includes: sub-step C1', applying glue to the opening of the hollow paper tube; and sub-step C2', bonding and fixing the nanofiber filter layer to one side of the hollow tube coated with glue.

[0065] Step D, connecting the hollow tube with the bonded nanofiber filter layer to one end of the filter rod, to complete Figure 1 the assembly of the filter cigarette.

[0066] In the embodiment, sub-step C1' further includes:

[0067] Sub-sub-step C1'a, arranging and fixing a plurality of hollow tubes in the mold, wherein each hollow paper tube passes through a corresponding paper tube slot in the mold, and the lower openings of the plurality of hollow tubes are aligned in the same plane.

[0068] Specifically, as shown in the figure, Figure 4A the mold is a flat plate arranged with N rows and N columns of equidistant circular holes, and the thickness of the flat plate is less than the height of the hollow tube. The diameter of the circular hole matches the diameter of the hollow paper tube, serving as a paper tube slot to fix the hollow paper tube tightly, and the thickness is 3mm-40mm, which is less than the height of the hollow paper tube when in use. The inner diameter of the hollow paper tube is 3mm-10mm, the thickness of the hollow paper tube is 0.1mm-1mm, and the height of the hollow paper tube is 5mm-50mm. The mold is moved by a hanging rocker arm. When executed, the hollow tube is placed into the mold by a conveying unit in an air flow assisted conveying mode, arranged and fixed, and the lower openings of the hollow paper tubes are aligned in the same plane.

[0069] Sub-sub-step C1'b, uniformly applying glue in the grooves of the glue plate unit, wherein the grooves on the glue plate unit correspond to the hollow paper tubes in the upper mold, as shown in the figure, Figure 4B ;

[0070] Sub-sub-step C1'c, controlling the mold to drop down so that the lower opening of each hollow paper tube is immersed in the glue in the corresponding groove, as shown in the figure,Figure 4C As shown;

[0071] In sub-step C1'c, the mold is lifted to detach each hollow tube from the glue, thus applying glue to the lower opening of each hollow tube.

[0072] Specifically, the bottom of the mold contains grooved glue plate units, with each groove corresponding to a hollow paper tube. A scraper distributes the glue in the grooves quantitatively and evenly. The lower opening of each hollow tube is immersed in the glue in the corresponding groove, where the glue acts as an adhesive. The mold is then lifted to detach each hollow tube from the glue, thus applying glue to the lower opening of each hollow tube.

[0073] In this embodiment, sub-step C2' includes:

[0074] In sub-step C2'a, the entire nanofiber membrane with the nanofiber filter layer is placed in a hot press under the mold, such as... Figure 4D As shown;

[0075] In sub-step C2'b, the mold is pressed down to bond and fix the lower openings of the multiple hollow tubes it carries to the nanofiber membrane with adhesive, and the residence time is preset to t2.

[0076] In sub-step C2'c, the nanofiber filter layer bonded to the hollow tube is cut or punched along the circumference along with the substrate, so that this part of the nanofiber filter layer and the substrate are separated from the rest of the whole nanofiber membrane.

[0077] Specifically, such as Figure 4D As shown, the nanofiber filter layer is moved and controlled by a lower roller, which operates in sync with the upper suspended rocker arm. Above the mold, there is a blade holder with annular blades corresponding to each hollow paper tube. After the hollow tube is bonded to the nanofiber membrane, the blade holder falls and cuts the nanofiber membrane bonded to the hollow tube, along with the spinning substrate, along the annular opening, separating this portion of the nanofiber membrane and spinning substrate from the other parts.

[0078] Those skilled in the art should understand that the above physical cutting with a blade is an example. In other embodiments of the present invention, laser cutting or other physical cutting methods can also be used to achieve the present invention and are also within the protection scope of the present invention.

[0079] In step C2'c, the hollow paper tube with the bonded nanofiber filter layer is released from the mold;

[0080] Specifically, such as Figure 4EAs shown, after the filter tip completes the adhesion cutting step, the mold is lifted and moved to the collection area, above the mold, there is a punching plate. The punching plate has a cylindrical punching part corresponding to each hollow paper tube. The punching part falls to separate the filter tip semi-finished product from the mold, which is collected by the lower collection box and enters the final cigarette assembly link.

[0081] Those skilled in the art should understand that the above template, blade holder, punching holder, etc. are made of materials including but not limited to acrylic plate, stainless steel plate, and any plate with certain thickness and hardness.

[0082] The following describes the details of each component of the filter tip of the present embodiment and the manufacturing process.

[0083] ① Filter stick

[0084] In the present embodiment, the filter stick is a filter stick for cigarettes in the prior art. The hollow tube with a nanofiber filter layer is connected to one end of the cellulose acetate stick.

[0085] It should be noted that due to the division of labor among different production units, filter tips without filter sticks can be manufactured, sold, and offered for sale independently, which also have the beneficial effects described in the present application and are within the scope of protection of the present application.

[0086] ② Glue

[0087] In the present embodiment, the nanofiber membrane is adhered and fixed to one end of the hollow tube by glue. The glue is one of the following materials: gelatin, starch, gum arabic, and sodium alginate.

[0088] Those skilled in the art should understand that the above types of glue are only examples. In other embodiments of the present application, other types of glue can also be used to achieve the present application and are within the scope of protection of the present application.

[0089] ③ Carrier

[0090] In the present embodiment, the hollow paper tube is used as a carrier, and the thickness of the paper is between 0.1 mm and 0.5 mm, and the height is between 5 mm and 50 mm. The inner diameter of the hollow tube is between 3 mm and 10 mm to adapt to different cigarette categories.

[0091] Those skilled in the art should understand that using a hollow paper tube as a carrier for the nanofiber filter layer has the advantages of low cost, compatibility with existing cigarette manufacturing processes, and easy industrial production.

[0092] Those skilled in the art should understand that although the hollow pipe in this embodiment is made of paper, the present application is not limited thereto. In other embodiments of the present application, the material of the carrier can also be other hard deformable film materials with certain support, not limited to hollow tubes, but also to cylinders with a certain thickness, as long as they can carry the nanofiber membrane, and all of them can realize the present application and are within the protection scope of the present application.

[0093] (4) One end or both ends of the carrier is covered with a nanofiber filter layer

[0094] Although the nanofiber filter layer in this embodiment is only covered on one end of the hollow paper tube, in other embodiments of the present application, both ends of the hollow paper tube are covered with a nanofiber membrane, and the shape of the filter tip is maintained by the hardness of the hollow paper tube itself, as shown in Figure 5

[0095] (5) Sheet-shaped nanofiber membrane

[0096] In the prior art, most filter materials are in the shape of a cylinder, i.e., the ratio of the lateral extension size to the axial size is less than 1:1.

[0097] In this embodiment, the nanofiber membrane as the filter material is in the shape of a sheet, and the ratio of the lateral extension size to the axial size of the nanofiber membrane is greater than 5:1. By such arrangement, batch coating is facilitated, and the existing acetate fiber rod is compatible, which does not greatly affect the size of the existing cigarette and is more easily accepted by production enterprises and consumers.

[0098] (7) Presence or absence of the spinning base material

[0099] In this embodiment, a cellulose non-woven fabric with low grammage (less than 40 g / m2), small suction resistance and meeting environmental protection requirements is used as the spinning base material, such as a bamboo fiber non-woven fabric, a polylactic acid non-woven fabric and a viscose non-woven fabric. In this case, the spinning base material does not need to be removed in the steps of making the filter tip and the finished cigarette, and the filter tip can be directly bonded and cut with the tobacco paper rod, which reduces the requirement for cutting precision and simplifies the production steps.

[0100] Those skilled in the art should understand that other spinning base materials can also be used to realize the present application, such as PE film, PP film, release paper and other materials with certain support and hardness. However, in this case, the step of removing the spinning base material needs to be added in the subsequent process of making the filter tip and the finished cigarette.

[0101] (8) Material of the nanofiber filter layer

[0102] ​In the present application, the nanofiber filter layer is prepared by electrospinning technology. The material for electrospinning can be aqueous polyurethane, polyester, polyether, cellulose acetate (CA), polylactic acid (PLA), polyimide (PI), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), etc. The solvent used for electrospinning is acetone, dimethylformamide, dimethylacetamide, etc. The solid content of the electrospinning solution is 10-35%, and the electrospinning parameters are as follows: voltage 10-50kv, temperature 20-40℃, humidity 10-60RH%, spinning distance 5-30cm, and feeding rate 0.1-3ml / h.

[0103] In the prior art, most of the polymers used for electrospinning need to be dissolved in organic solvents before spinning, and the organic solvents have certain toxicity.

[0104] In the present embodiment, the material for electrospinning of the nanofiber filter layer can also be aqueous polyurethane emulsion, the solvent used is water, and the spinning aid material used is polyvinyl alcohol, polyethylene oxide, etc. The solid content of the aqueous polyurethane is 20-40%, the template polymer content is 0.1-5%, and the electrospinning parameters are as follows: voltage 10-50kv, temperature 20-40℃, humidity 10-60RH%, spinning distance 5-30cm, and feeding rate 0.1-3ml / h.

[0105] Unlike the prior art, the polyurethane emulsion used in the aqueous polyurethane scheme in the present embodiment is an aqueous system, i.e. no organic solvent is needed, the polyurethane material is directly dispersed in the aqueous solution, which is more environmentally friendly, and avoids incomplete volatilization of the organic solvent during electrospinning and storage of the nanofiber filter layer, and the harm of residual solvent inhalation to the human body.

[0106] 9. Nanofiber filter layer composed of coarse and fine fibers

[0107] In the present embodiment, the fiber thickness of the nanofiber filter layer prepared by electrospinning is in the range of 2-15μm, wherein the nanofiber filter layer includes coarse fibers and fine fibers, wherein the fine fibers have a diameter of 200nm-1μm, and the coarse fibers have a diameter of 1-3μm.

[0108] As for the combination mode of coarse and fine fibers, there are the following two modes:

[0109] 9.1 Nanofiber filter layer composed of coarse and fine fibers

[0110] When coarse and fine fibers are mixed, based on multi-needle electrospinning, the solution in N needle tubes in the same row is A solution, and the solution in M needle tubes is B solution, N and M needle tubes can be distributed according to different rules, wherein the raw materials of A and B solutions can be the same material or different materials, and by adjusting different parameters such as concentration and conductivity, nanofibers with different thicknesses can be obtained under the same spinning conditions.

[0111] 9. 2-layered nanofiber filter layer of coarse and fine fibers

[0112] When the coarse and fine fiber layer is combined, N rows of needle tubes are designed for spinning, wherein the first M rows of all needle tubes are A solution, and the solution in the last (N-M) rows of all needle tubes is B solution, the solution parameters are controlled as above, and the spinning parameters (such as voltage, spinning distance, feeding speed, etc.) of different spinning units are adjusted to adjust the difference in fiber fineness before and after. Figure 6A and Figure 6B are electron micrographs of the diameter distribution of the fine and coarse fibers laminated in the nanofiber filter layer, respectively.

[0113] In the present application, through the nanofiber filter layer composed of the blending / lamination of coarse fibers and fine fibers, different particle sizes of tar particles can be effectively intercepted, the interception and adsorption of carcinogenic particulate matter below micron level can be realized, and the porosity can be improved to avoid the problem of excessive suction resistance.

[0114] So far, the second embodiment of the filter cigarette holder of the present application has been introduced.

[0115] The third embodiment of the filter cigarette holder of the present application will be introduced below. The same parts of the second embodiment will not be repeated, and the special features of the present embodiment will be mainly introduced.

[0116] In the present embodiment, the nanofiber membrane is used as the filter layer and the adhesive layer, a new industrialized way combined with the cellulose acetate rod is designed, which can simplify the production process and improve the production efficiency.

[0117] Figure 7 is a schematic view of a cigarette containing the third embodiment of the filter cigarette holder of the present application. As shown in Figure 7 , the filter cigarette holder of the present embodiment comprises:

[0118] a filter rod 32;

[0119] a nanofiber membrane 22 in the form of a sheet, comprising:

[0120] a nanofiber filter layer;

[0121] a nanofiber adhesive layer formed on the nanofiber filter layer;

[0122] wherein the nanofiber filter layer is fixed to the filter rod by the nanofiber adhesive layer, and the tobacco segment A is fixed to the side of the nanofiber membrane away from the filter rod.

[0123] In this embodiment, the adhesive substance is added in the form of electrostatic spinning, and the nanometer or micrometer-sized bead-shaped adhesive points are formed on the surface of the nanometer membrane through the bead string morphology of the spinning, so that the nanometer membrane is effectively adhered and the pores are not blocked to cause the absorption resistance to decrease.

[0124] Figure 8 For Figure 7 A flow chart of the preparation method of the filter cigarette is shown in Fig. 1. Figures 9A-9D For Figure 8 A schematic diagram of the intermediate product of the filter cigarette after each step of the preparation method is shown in Fig. 2. Figure 8 As shown in Fig. 1, the preparation method of the filter cigarette of this embodiment comprises the following steps:

[0125] Step A, preparing a filter rod;

[0126] In this embodiment, the carrier is the filter rod, i.e., the acetic acid fiber rod in the prior art. The diameter of the cigarette acetic acid fiber rod is 3 mm-10 mm, and the height is 30 mm-70 mm.

[0127] Step B, preparing a sheet-shaped nanometer fiber membrane;

[0128] The nanometer fiber membrane is prepared by electrostatic spinning using special materials, and the spinning base material for receiving the nanometer fiber membrane is a thin film material with a smooth plane. In this embodiment, step B comprises the following sub-steps:

[0129] Sub-step B1, forming a nanometer fiber filter layer on the spinning base material by electrostatic spinning;

[0130] In this embodiment, the nanometer fiber filter layer is prepared by electrostatic spinning, and the material is water-based polyurethane, polyester, polyether, cellulose acetate (CA), polylactic acid (PLA), polyimide (PI), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), etc., and the solvent used is acetone, dimethylformamide, dimethylacetamide, etc. The solid content of the electrostatic spinning liquid is 10-35%, and the electrostatic spinning parameters are as follows: voltage 10-50 kv, temperature 20-40℃, humidity 10-60 RH%, spinning distance 5-30 cm, and feeding rate 0.1-3 ml / h. The fiber thickness of the nanometer fiber filter layer prepared by electrostatic spinning is 2-15 μm.

[0131] In the prior art, most of the polymers used for electrostatic spinning need to be dissolved in organic solvents before spinning, and the organic solvents have certain toxicity.

[0132] In this embodiment, the electrospinning material of the nanofiber filter layer can also be a water-based polyurethane emulsion, the solvent used is water, and the auxiliary spinning material used is polyvinyl alcohol, polyethylene oxide, etc. The solid content of the water-based polyurethane is 20-40%, the template polymer content is 0.1-5%, and the electrospinning parameter range is as follows: voltage 10-50kv, temperature 20-40℃, humidity 10-60RH%, spinning distance 5-30cm, and feeding rate 0.1-3ml / h.

[0133] Preferably, the polyurethane emulsion used in the water-based polyurethane scheme in this embodiment is a water-based system, i.e. no organic solvent is needed, the polyurethane material is directly dispersed in the aqueous solution, which is more environmentally friendly and avoids incomplete volatilization of organic solvents during the electrospinning process of the nanofiber filter layer and storage, and the hazards of inhaling residual solvents to the human body.

[0134] In this embodiment, the substrate for receiving the nanomembrane is one of a non-woven fabric, a release paper, a PE film, a PP film, etc.

[0135] The solid content of the electrospinning solution is 10-35%, wherein the solid content of the water-based polyurethane is 20-40% and the template polymer content is 0.1-5%, and the electrospinning parameter range is as follows: voltage 10-50kv, temperature 20-40℃, humidity 10-60RH%, spinning distance 10-20cm, and feeding rate 0.1-3ml / h. The nanofiber filter layer prepared by electrospinning has a fiber thickness range of 2-15μm. In this embodiment, the nanofiber filter layer is composed of a coarse fiber and a fine fiber, a coarse fiber layer and a fine fiber layer, or a pure coarse fiber / fine fiber scheme, which can be adjusted according to the diameter of the cellulose acetate rod to ensure that there is no excessive suction resistance, wherein the diameter of the fine fiber is 200nm-1μm and the diameter of the coarse fiber is 1-3μm.

[0136] Sub-step B2, forming a nanofiber adhesive layer on the nanofiber filter layer by electrospinning, wherein the spinning substrate, the nanofiber filter layer formed on the substrate, and the nanofiber adhesive layer form a nanofiber membrane.

[0137] The thickness ratio of the nanofiber adhesive layer and the nanofiber filter layer is between 1:2 and 1:50; the material of the nanofiber adhesive layer includes one or more of the following: polyvinyl butyral, polyvinyl alcohol, polyester. The solvent for preparing the nanofiber adhesive layer includes one or more of the following: acetone, dimethylformamide, dimethylacetamide; the solid content of the electrospinning solution for preparing the nanofiber adhesive layer is between 4 and 20%; the electrospinning parameter range is as follows: voltage 10-50kV, temperature 20-40℃, humidity 10-60RH%, spinning distance 10-20cm, feeding rate 0.1-3ml / h; the thickness ratio of the nanofiber adhesive layer and the nanofiber filter layer is between 1:2 and 1:50; the fiber thickness of the nanofiber adhesive layer ranges from 0.2 to 1μm, and the nanofiber form is a string bead structure to provide point-like bonding sites.

[0138] Those skilled in the art should understand that the above material types and process parameters are only used as examples. In other embodiments of the present application, other materials and other process parameters can also be selected according to the actual scene needs, and the present application can also be implemented, which is also within the protection scope of the present application.

[0139] In step C, the nanofiber filter layer is bonded and fixed to one end or both ends of the filter rod through the nanofiber adhesive layer.

[0140] In this embodiment, the nanofilm filter layer is bonded to the acetate fiber rod through the nanofilm adhesive layer. The mold is a flat plate with N rows and N columns of equidistant circular holes; the mold is moved and controlled by a hanging rocker arm from above, and the nanofiber film is moved and controlled by the front and rear conveying rollers from below, and the up-down control movement and stay are the same frequency. The mold includes but is not limited to acrylic plate, stainless steel plate, and can be any kind of plate with certain thickness and hardness.

[0141] Step C further includes:

[0142] Sub-step C1, arrange and fix a plurality of acetate fiber rods by the mold, wherein each acetate fiber rod passes through the corresponding clamping slot in the mold, and the lower tube openings of the plurality of hollow tube pieces are aligned in the same plane;

[0143] Specifically, the acetate fiber rods are arranged and fixed by the mold, and the lower ends are aligned in the same plane, as shown in Figure 9A .

[0144] Sub-step C2, place the entire nanofiber film on the hot pressing equipment below the mold, and the temperature of the hot pressing equipment is higher than the temperature at which the nanofiber adhesive layer exhibits adhesion;

[0145] Sub-step C3, control the mold of the bearing to press down, so that the filter rod lower ring opening is pressed on the nanofiber adhesive layer of the nanofiber film, and stay for a preset time t1.

[0146] Specifically, the nanofiber membrane is passed through a hot-pressing device, a hot plate heats the nanofiber membrane thereon, a lower mold is lowered to make the acetate fiber rod contact the nanofiber membrane, the nanofiber membrane contacts the hot-pressing device and stays for 5-15 seconds. During hot-pressing, the adhesive of the nanofiber adhesive layer is hot-melted to play a role of adhesion. Figure 9B

[0147] Sub-step C4, the nanofiber filter layer after being adhered to the filter rod is cut or punched along the rod lower ring to separate it from the substrate; or the nanofiber filter layer after being adhered to the filter rod is cut or punched along the ring together with the substrate to separate the nanofiber filter layer and the substrate from the other part of the nanofiber membrane;

[0148] Specifically, the nanofiber membrane after being adhered to the acetate fiber rod is cut or punched along the ring to separate it from the substrate, or is cut together with the substrate to obtain a final product. Figure 9C

[0149] Those skilled in the art should understand that the cutting method of the nanofiber membrane is not limited to blade punching and laser cutting, and can be any physical cutting method that can be achieved.

[0150] Sub-step C5, the filter rod with the adhered nanofiber filter layer is released from the mold.

[0151] Specifically, as shown in Figure 9D , after the filter tip completes the adhesion and cutting step, the mold is lifted and moved to a collection area. Above the mold, there is a punching plate. The punching plate has a cylindrical punching part corresponding to each hollow paper tube. The punching part falls to separate the filter tip semi-finished product from the mold and is collected by the lower collection box to enter the final cigarette assembly link.

[0152] Another aspect of the present application also provides a cigarette. In an exemplary embodiment of the present application, please refer to Figure 1 and Figure 5 , the cigarette of the present embodiment comprises:

[0153] a filter tip, which is the filter tip of the above embodiments;

[0154] a tobacco segment A arranged immediately upstream of the filter tip;

[0155] a tipping paper wrapped outside the filter tip and the tobacco segment.

[0156] So far, the various embodiments of the present application have been introduced. According to the above description, those skilled in the art should have a clear understanding of the present application.

[0157] ​​It should be noted that for certain implementations, if it is not the key content of the present application, and is well known to those skilled in the art, based on the limitation of the volume, it is not described in detail in the drawings or the text, at this time, it can be understood by referring to the related prior art.

[0158] For the numerical values and numerical ranges mentioned in the present application, unless explicitly indicated as the opposite, the numerical parameters in the specification and claims of the present application can be approximate values, which can be changed according to the content of the present application. Specifically, all the numbers indicating the content of composition, reaction conditions, etc. recorded in the specification and claims should be understood as being modified by the term "about" in all cases, which means that it contains the variation of ±10% in some embodiments from the specific number.

[0159] For the ordinal numbers used in the present application, such as "first", "second", "third", "main", "secondary", as well as Arabic numerals, letters, etc., the intention is only to make the corresponding element (or step) clear and distinguishable from another element (or step) with the same name, and does not mean that the element (or step) has any ordinal number, nor does it represent the order of one element (or step) and another element (or step).

[0160] For the steps in the present application, unless specifically described or steps that must occur in sequence, the order of the steps is not limited to the above list, and can be changed or rearranged according to the required design.

[0161] For the directional terms mentioned in the present application, such as "center", "lateral", "longitudinal", "top", "bottom", "upper", "lower", "front", "back", "left", "right", "inner", "outer", etc. The orientation or positional relationship indicated is only based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. Throughout the drawings, the same elements are represented by the same or similar reference numerals. In addition, the shapes and sizes of the components in the drawings do not reflect the true size and proportion, but only illustrate the content of the embodiments of the present application.

[0162] For the terms "connected", "connected" mentioned in the present application, unless otherwise specified and limited, these terms should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the connection of some part of two elements. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0163] It is to be understood that the word "comprising" does not exclude the presence of elements (or steps) other than those listed in a claim. The word "a" or "an" preceding the

[0164] Furthermore, the purpose of the embodiments described herein is to enable the patent claims to meet legal requirements. The present application as defined by the claims may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein.

[0165] Similarly, it is to be understood that the use of "a" or "one" of something in the description and / or claims herein is not to be construed as excluding the presence of two or more such things unless specifically stated otherwise. Rather, the use of "a" or "one" or the like is to be construed as meaning "one or more."

[0166] The above detailed description merely describes certain particular embodiments of the application, and is not intended to limit the application. The application is therefore to be considered in all respects as illustrative and not restrictive, since the scope of the application will be determined by the appended claims, and equivalents thereof.

Claims

1. A method of making a filter tip, characterized by, Comprising: Step A, preparing a carrier; Step B, preparing a sheet of nanofiber membrane; Step C, bonding the nanofiber membrane to one or both ends of the carrier.

2. The method of claim 1, wherein: In step A, the carrier is a filter rod; Step B comprises: Sub-step B1, forming a nanofiber filter layer on a spinning substrate by electrospinning; Sub-step B2, forming a nanofiber bonding layer on the nanofiber filter layer by electrospinning; Wherein the spinning substrate, the nanofiber filter layer formed thereon, and the nanofiber bonding layer form an integral filter layer; In step C, the nanofiber filter layer is bonded to one or both ends of the filter rod through the nanofiber bonding layer.

3. A method according to claim 2, wherein the filter tip is formed by, In sub-step B2, The material for preparing the nanofiber bonding layer includes one or more of the following: polyvinyl butyral, polyvinyl alcohol, low-melting polyester; And / or, the solvent for preparing the nanofiber bonding layer includes one or more of the following: acetone, dimethylformamide, dimethylacetamide; And / or, the solid content of the electrospinning solution for preparing the nanofiber bonding layer is 4-20%; And / or, the electrospinning parameters are as follows: voltage 10-50 kV, temperature 20-40℃, humidity 10-60 RH%, spinning distance 10-20 cm, feeding rate 0.1-3 ml / h; And / or, the thickness ratio of the nanofiber bonding layer to the nanofiber filter layer is between 1:2 and 1:50 And / or, the fiber thickness of the nanofiber bonding layer is 0.2-1 μm, and the nanofiber form is a string bead structure to provide point-like bonding sites.

4. A filter tip production method according to claim 2, characterised in that, Step C comprises: Sub-step C1, arranging and fixing a plurality of filter rods in the mold, wherein each filter rod passes through a corresponding fixing hole in the mold, and the lower openings of a plurality of hollow tubes are aligned in the same plane; Sub-step C2, placing the entire nanofiber membrane on a hot pressing device below the mold, and the temperature of the hot pressing device is higher than the temperature at which the nanofiber bonding layer becomes sticky; Sub-step C3, controlling the mold to press down, so that the lower ring opening of the filter rod presses on the nanofiber bonding layer of the nanofiber membrane, and stays for a preset time t1; Sub-step C4, cutting or punching the nanofiber filter layer bonded with the filter rod along the lower ring opening of the filter rod, so that it is separated from the spinning substrate; or cutting or punching the nanofiber filter layer bonded with the filter rod together with the spinning substrate along the ring opening, so that part of the nanofiber filter layer together with the spinning substrate is separated from the other part of the entire nanofiber membrane; Sub-step C5, releasing the filter rod with the bonded nanofiber filter layer from the mold.

5. The method of claim 1, wherein: In step A, the carrier is a hollow tube; Step B comprises: Sub-step B1, forming a nanofiber filter layer on a spinning substrate by electrospinning; Wherein the spinning substrate and the nanofiber filter layer formed thereon form an integral filter layer; Step C comprises: Sub-step C1', applying glue to the tube opening of the hollow tube; Sub-step C2', bonding the nanofiber filter layer to the side of the hollow tube coated with glue.

6. The filter tip manufacturing method according to claim 5, wherein, The sub-step C1' comprises: Sub-sub-step C1'a, arranging and fixing a plurality of hollow tubes in the mold, wherein each hollow tube passes through a corresponding fixed hole in the mold, and the lower tube openings of the plurality of hollow tubes are aligned in the same plane; Sub-sub-step C1'b, uniformly distributing glue in the grooves of the glue plate unit, wherein the grooves on the glue plate unit correspond to the hollow tubes in the mold above; Sub-sub-step C1'c, controlling the mold to drop down so that the lower tube opening of each hollow tube is immersed in the glue in the corresponding groove; Sub-sub-step C1'c, controlling the mold to lift up so that each hollow tube is separated from the glue, thereby achieving glue coating on the lower tube opening of each hollow tube; And / or, the sub-step C2' comprises: Sub-sub-step C2'a, placing the entire nanofiber membrane formed with the nanofiber filter layer on the platform below the mold; Sub-sub-step C2'b, controlling the mold to press down so that the lower tube openings of the plurality of hollow tubes coated with glue carried by the mold are bonded to the nanofiber membrane, and staying for a preset time t2; Sub-sub-step C2'c, cutting or punching the nanofiber filter layer bonded to the hollow tube along the circle opening so that it is separated from the substrate; or cutting or punching the nanofiber filter layer bonded to the hollow tube along the circle opening together with the substrate so that part of the nanofiber filter layer together with the substrate is separated from the other part of the entire nanofiber membrane; Sub-sub-step C2'c, releasing the hollow tube bonded with the nanofiber filter layer from the mold; And / or, the step C is followed by a step D of connecting the hollow tube bonded with the nanofiber filter layer to one end of the filter rod.

7. The filter tip manufacturing method according to claim 4 or 6, wherein, The preset time t1 is between 5-15s, and the preset time t2 is between 5-15s; And / or, the electrospinning solution for preparing the nanofiber filter layer is a polyurethane emulsion in an aqueous system; And / or, the mold is a flat plate arranged with M rows and N columns of equidistant circular holes, the diameter of the circular holes matches the diameter of the hollow tube, and the thickness of the flat plate is less than the height of the hollow tube; And / or, the mold is moved by an upper hanging rocker arm, the entire nanofiber membrane is moved by a lower roller, and the upper hanging rocker arm and the lower roller are controlled at the same frequency; And / or, the nanofiber filter layer comprises coarse fibers and fine fibers with different diameters, wherein the diameter of the fine fibers is between 200nm-1μm, and the diameter of the coarse fibers is between 1-3μm, and the sub-step B1 comprises: By adjusting the concentration, conductivity, and spinning parameters of the electrospinning solution, coarse fibers and fine fibers are simultaneously spun on the textile substrate to form a nanofiber filter layer with disordered arrangement of coarse fibers and fine fibers; Or, by adjusting the arrangement of the spinning needle and the concentration, conductivity, and spinning parameters of the electrospinning solution, a coarse fiber filter layer is first formed on the textile substrate, and then a fine fiber filter layer is formed, thereby forming a nanofiber filter layer with laminated coarse and fine fibers.

8. The filter tip manufacturing method according to claim 4 or 6, wherein, in the step B, the spun base material is a peelable base material; and in the step C, the nanofiber filtration layer bonded to the carrier is cut or punched along the lower circle opening of the carrier to separate the nanofiber filtration layer from the peelable base material; or, in the step B, the base material is a non-peelable base material; and in the step C, the nanofiber filtration layer bonded to the carrier is cut or punched along the lower circle opening of the carrier to separate the nanofiber filtration layer from the non-peelable base material.

9. A filter tip, characterised in that The filter tip manufactured by the filter tip manufacturing method according to any one of claims 1 to 6 or 8.

10. A cigarette, characterized by The filter tip comprises: a filter tip according to claim 9; a tobacco segment disposed immediately upstream of the filter tip; a tipping paper wrapped around the outside of the filter tip and the tobacco segment.

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