Method for producing a nonwoven fabric and use thereof
By improving the preparation method of nonwoven fabrics, using lyocell fibers and other biodegradable fibers, and combining cross-laying and tensile differences, a nonwoven fabric with micro-wrinkles was prepared for use in filter rods. This solved the problems of insufficient environmental friendliness and filtration performance of filter rod materials, achieved efficient adsorption of tar and nicotine, and shortened the degradation time.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SICHUAN SANLIAN NEW MATERIAL CO LTD
- Filing Date
- 2024-11-20
- Publication Date
- 2026-06-19
AI Technical Summary
Existing filter rod materials, such as cellulose acetate tow and paper filter rods, are insufficient in terms of environmental friendliness and filtration performance. cellulose acetate tows biodegrade slowly, leading to pollution, while paper filter rods have good filtration performance but weak smoke smell and insufficient aroma. Existing nonwoven fabric preparation methods cannot meet the requirements of filter rods.
Nonwoven fabrics are prepared by mixing lyocell fibers with other biodegradable fibers, applying different tensions through cross-laying, combined with hydrophobic modified solvents and reinforcement methods. Different tensions are applied during the laying and reinforcement process to form micro-wrinkles, which are then used in filter rods. The fabrics are then wrinkled and embossed before rolling.
It increases the surface area of the nonwoven fabric and its adsorption effect on tar and nicotine, shortens the degradation time, and improves the inhalation experience of the filter rod.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of cigarette filter rods, specifically relating to a method for preparing and applying a nonwoven fabric. Background Technology
[0002] Currently, most filter rods on the market use cellulose acetate tow as the main filter material. It has good elasticity and thermal stability, and can effectively trap harmful components such as tar and nicotine in cigarette smoke, making it an excellent filter material for tobacco use. However, cellulose acetate tow has a long biodegradation time, leading to incineration and landfilling as the main methods for disposing of discarded filter rods, causing significant environmental pollution.
[0003] To achieve tar reduction, harm mitigation, and biodegradability, paper filter rods have been researched both domestically and internationally. These are made from sheets of natural plant fibers that are pleated and rolled, offering strong biodegradability and low raw material costs. Paper filter rods exhibit significantly better filtration performance for harmful substances such as tar in flue gas, giving them a greater advantage in tar reduction and harm mitigation. However, due to their high retention rate of various components in flue gas, they also bring problems such as a weaker tobacco flavor, insufficient aroma, and a stronger papery taste.
[0004] Therefore, existing technologies propose the use of nonwoven fabrics for filter rod production. Currently, the production process of nonwoven fabrics basically involves mixing, opening, web formation, web laying, reinforcement, and drying of raw fiber materials used to prepare nonwoven fabrics. For example, CN 112831911 A discloses a nonwoven fabric and its preparation method. This technical solution is for the preparation of nonwoven fabrics using cellulose acetate. However, this technical solution is for the manufacture of mask substrates. Although its preparation method can also achieve the preparation of nonwoven fabrics for filter rods, it cannot fully meet the performance requirements of subsequent filter rod rolling and cigarette filter rods. Summary of the Invention
[0005] The purpose of this invention is to provide a method for preparing and applying nonwoven fabrics. It is based on the prior art and has been improved to solve the problems existing in the background art.
[0006] To achieve the above objectives, this application employs the following technical solution:
[0007] A method for preparing a nonwoven fabric includes the following steps:
[0008] S1. Mixing and opening process:
[0009] According to the design of the nonwoven fabric's number of layers and the composition of the raw material fibers, the raw material fibers of each layer are loosened to ensure that the raw material fibers of the layer are mixed evenly.
[0010] S2, Web forming process:
[0011] The mixed fibers in each layup are formed into a thin fiber web using a web-forming method;
[0012] S3. Mesh laying process:
[0013] The thin fiber web from step S2 is laid sequentially using a cross-laying method, and during the laying process, the tension on each layer of thin fiber web is not exactly the same, but is maintained.
[0014] S4. Reinforcement process:
[0015] The fiber web after the web is laid is reinforced to obtain a nonwoven fabric. Throughout this process, the tension on each thin fiber web layer is kept the same as that in step S3.
[0016] S5. Drying process:
[0017] The reinforced nonwoven fabric is dried to the set moisture content.
[0018] Furthermore, the raw material fiber in step S1 is lyocell fiber, and one or more of polylactic acid fiber, viscose fiber, bamboo pulp fiber, cotton pulp fiber, mahjong fiber, and wood pulp fiber.
[0019] Furthermore, in step S1, the content of lyocell fiber in the raw material fiber of each layup is not entirely the same in that layup.
[0020] Furthermore, in step S2, the web forming method uses combing web forming or airflow web forming.
[0021] Furthermore, in step S3, if the number of plies is odd, the tension of the middle ply is the greatest; if the number of plies is even, the tension of the two middle plies is the greatest.
[0022] Furthermore, in step S3, a hydrophobic modified solvent is sprayed during the web laying process, including one or more of silica, zinc oxide polystyrene, calcium carbonate, polytetrafluoroethylene, polydimethylsiloxane, polyvinylidene fluoride, polypropylene, polyethylene, or polyacrylonitrile.
[0023] Furthermore, in step S3, a flame retardant is added to the hydrophobic modified solvent, wherein the flame retardant is one or more of the following: metal hydroxides, antimony-based flame retardants, and halogen-based flame retardants.
[0024] Furthermore, in step S4, the reinforcement method uses hydroentanglement reinforcement, needle reinforcement, and a combination of needle reinforcement and hydroentanglement reinforcement.
[0025] One application is the use of the nonwoven fabric prepared by any of the above-described methods in a filter rod.
[0026] Furthermore, the nonwoven fabric is pleated and cut before being used in filter rods.
[0027] The beneficial effects of this invention are:
[0028] The nonwoven fabric preparation method of this technical solution is an improvement on the existing nonwoven fabric preparation method. By applying different tensile forces to different layers during the web laying process, the tensile forces of each fiber inside are different after reinforcement and molding. After drying, the surface of the finished product will have tiny wrinkles. Combined with the wrinkle embossing and cutting embossing before rolling the filter rod, the surface area of the nonwoven fabric is further increased. Furthermore, the filter rod rolled from the nonwoven fabric prepared by this method, during the suction process, the heating of the nonwoven fabric by the flue gas causes the bonding layer material to soften and the internal deformation to increase. This improves the adsorption of tar and nicotine, and the deformation of the internal structure of the nonwoven fabric reduces the degradation time. Detailed Implementation
[0029] The technical solutions of the present invention will be described in detail below through embodiments. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solutions of the present invention, and should not be construed as limiting the technical solutions of the present invention.
[0030] The method for preparing nonwoven fabrics involved in this application is an improvement on existing nonwoven fabric technology, adapted to make the prepared nonwoven fabric suitable for use in cigarette filter rods.
[0031] The nonwoven fabrics prepared by the method of this application are all made from biodegradable fibers, and Lyocell fiber is an essential raw material for modifying bio-based fibers. Example 1
[0032] A nonwoven fabric is prepared from lyocell fiber and wood pulp fiber, wherein the lyocell fiber content is 90 wt% and the wood pulp fiber content is 10 wt%; the following steps are used:
[0033] (1) Mixing and opening: The two types of fibers are mixed evenly in proportion; In this embodiment, the number of web layers is 6, wherein the middle two layers have the same Lyocell fiber content, the two surface layers have the same Lyocell fiber content, the remaining two layers have the same Lyocell fiber content, and the two surface layers have the highest Lyocell fiber content, while the middle two layers have the lowest Lyocell fiber content. After combining, the Lyocell fiber content is 90wt%, and the wood pulp fiber content is 10wt%.
[0034] (2) Web formation: In the carding stage, a carding process is used to form a fiber web from the fibers to be carded.
[0035] (3) Net laying: In the net laying stage, a cross-laying method is adopted, and the number of net layers is 6. During the net laying process, the tension on each layer is not exactly the same. The tension on the two middle layers is the highest, and the tension on the two surface layers is the lowest. The highest tension is 1.2 times the lowest tension.
[0036] (4) Reinforcement: Place the fiber web on the web laying curtain. As the web laying curtain moves, the fiber web enters the flat web hydroentangling area for hydroentangling. After hydroentangling, excess water is squeezed out by the liquid rolling roller.
[0037] (5) Drying: Dry the hydroentangled nonwoven fabric.
[0038] The basis weight of this nonwoven fabric is 45 g / m². 2 The tensile strength is 30N and the thickness is 260um.
[0039] Nonwoven fabric is cut into 100mm wide pieces, rolled into rolls, and then embossed with a 1mm wide pleating process on a filter rod forming machine. The resulting rolls are then rolled into filter rods (Filter Rod A) with a circumference of 24.00mm and a length of 100mm. The measured pressure drop of the filter rod is 1000Pa. The filter rods undergo soil degradation experiments and degrade within 30 days. The filter rods are then rolled into cigarettes for evaluation. Compared to acetate fiber filter rods (Filter Rod B), the smoke emission data are as follows.
[0040]
[0041] This example shows a significant reduction in harmful substances such as nicotine. Example 2
[0042] The nonwoven fabric is made from hydrophobically modified lyocell fibers (commercially available) and conventional lyocell fibers (commercially available), with the hydrophobically modified lyocell fiber content being 40 wt% and the conventional lyocell fiber content being 60 wt%.
[0043] (1) Mixing and opening: The two types of fibers are mixed evenly in proportion; In this embodiment, the number of web layers is 5, of which the content of hydrophobic modified lyocell fiber in the middle layer is the lowest, and the content of hydrophobic modified lyocell fiber in the two surface layers is the highest. After the combination, the content of hydrophobic modified lyocell fiber is 40wt%, and the content of conventional lyocell fiber is 60wt%.
[0044] (2) Web formation: In the carding stage, a carding process is used to form a fiber web from the fibers to be carded.
[0045] (3) Net laying: In the net laying stage, a cross-laying method is adopted, with 5 layers of net. During the net laying process, the tension on each layer is not exactly the same. The tension on the middle layer is the highest, and the tension on the two surface layers is the lowest. The highest tension is 1.1 times the lowest tension.
[0046] (4) Reinforcement: Place the fiber web on the web laying curtain. As the web laying curtain moves, the fiber web enters the flat web hydroentangling area for hydroentangling. After hydroentangling, excess water is squeezed out by the liquid rolling roller.
[0047] (5) Drying: Dry the hydroentangled nonwoven fabric.
[0048] The basis weight of this nonwoven fabric is 35 g / m². 2 The breaking strength is 26N and the thickness is 185um.
[0049] Nonwoven fabric is cut into 140mm wide pieces, rolled into rolls, and then embossed with a 1mm wide pleating process on a filter rod forming machine. The resulting rolls are then rolled into filter rods (Filter Rod C) with a circumference of 24.00mm and a length of 100mm. The measured pressure drop of the filter rod is 1200Pa. The filter rods undergo soil degradation experiments and degrade within 30 days. The filter rods are then rolled into cigarettes for evaluation. Compared to acetate fiber filter rods (Filter Rod D), the smoke emission data are as follows.
[0050]
[0051] As can be seen in this example, no significant changes were observed in harmful substances such as nicotine. Example 3
[0052] The nonwoven fabric is made of lyocell fiber, wood pulp fiber, and bamboo pulp fiber, with a lyocell fiber content of 50 wt%, a wood pulp fiber content of 30 wt%, and a bamboo pulp fiber content of 20 wt%.
[0053] (1) Mixed opening: The above three types of fibers are mixed evenly in proportion; the number of web layers is 7, of which the lyocell fiber content in the middle layer is the lowest, the lyocell fiber content in the two surface layers is the highest, and the lyocell fiber content in the two layers between the middle layer and the surface layers is increased by the same amount. After the combination, the lyocell fiber content is 50wt%, the wood pulp fiber content is 30wt%, and the bamboo pulp fiber content is 20wt%.
[0054] (2) Web formation: In the carding stage, a carding process is used to form a fiber web from the fibers to be carded.
[0055] (3) Net laying: In the net laying stage, a cross-laying method is adopted, and the number of net layers is 7. During the net laying process, the tension of each layer is not exactly the same. The tension of the middle layer is the highest, and the tension of the two surface layers is the lowest. The tension of the middle layer is between the two tension values, and the highest tension is 1.25 times the lowest tension.
[0056] (4) Spraying: Spraying silica hydrophobic material or metal hydroxide flame retardant.
[0057] (5) Reinforcement: Place the fiber web on the web laying curtain. As the web laying curtain moves, the fiber web enters the flat web hydroentangling area for hydroentangling. After hydroentangling, excess water is squeezed out by the liquid rolling roller.
[0058] (6) Drying: Dry the hydroentangled nonwoven fabric.
[0059] The basis weight of this nonwoven fabric is 45 g / m². 2 The tensile strength is 30N and the thickness is 200um.
[0060] Nonwoven fabric is slit into 130mm wide pieces, rolled into rolls, and then embossed on a filter rod forming machine with a 1mm embossing width. It is then rolled into a filter rod with a circumference of 23.75mm and a length of 120mm. Finally, using industry-recognized composite filter rod technology, this filter rod is combined with a cellulose acetate filter rod to form a filter rod CE with a circumference of 24.20mm and a length of 120mm. Actual measurements show a filter rod pressure drop of 2000Pa. The filter rods were then used to make cigarettes for evaluation. Compared to cellulose acetate filter rods (filter rod F), the smoke performance data are as follows.
[0061]
[0062] This example shows a significant reduction in harmful substances such as nicotine.
[0063] Although the invention has been described herein with reference to illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter combination within the scope of this disclosure. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.
Claims
1. A method for producing a nonwoven fabric, characterized by, Includes the following steps: S1. Mixing and opening process: According to the design of the nonwoven fabric's number of layers and the composition of the raw material fibers, the raw material fibers of each layer are loosened to ensure that the raw material fibers of the layer are mixed evenly. S2, Web forming process: The mixed fibers in each layup are formed into a thin fiber web using a web-forming method; S3. Mesh laying process: The thin fiber web from step S2 is laid sequentially using a cross-laying method, and during the laying process, the tension on each layer of thin fiber web is not exactly the same, but is maintained. S4. Reinforcement process: The fiber web after the web is laid is reinforced to obtain a nonwoven fabric. Throughout this process, the tension on each thin fiber web layer is kept the same as that in step S3. S5. Drying process: The reinforced nonwoven fabric is dried to the set moisture content.
2. The method for producing a nonwoven fabric according to claim 1, characterized by, The raw material fiber in step S1 is lyocell fiber, and one or more of polylactic acid fiber, viscose fiber, bamboo pulp fiber, cotton pulp fiber, mahjong fiber, and wood pulp fiber.
3. The method for producing a nonwoven fabric according to claim 2, characterized by, In step S1, the content of lyocell fiber in the raw material fiber of each layup is not entirely the same in that layup.
4. The method for producing a nonwoven fabric according to claim 1, wherein In step S2, the web forming method uses combing web forming or airflow web forming.
5. The method for preparing the nonwoven fabric according to claim 1, characterized in that, In step S3, if the number of plies is odd, the tension of the middle ply is the greatest; if the number of plies is even, the tension of the two middle plies is the greatest.
6. The method for preparing the nonwoven fabric according to claim 1, characterized in that, In step S3, a hydrophobic modified solvent is sprayed during the mesh laying process, including one or more of the following: silica, zinc oxide polystyrene, calcium carbonate, polytetrafluoroethylene, polydimethylsiloxane, polyvinylidene fluoride, polypropylene, polyethylene, or polyacrylonitrile.
7. The method for preparing the nonwoven fabric according to claim 6, characterized in that, In step S3, a flame retardant is added to the hydrophobic modified solvent. The flame retardant is one or more of the following: metal hydroxides, antimony-based flame retardants, and halogen-based flame retardants.
8. The method for preparing the nonwoven fabric according to claim 1, characterized in that, In step S4, the reinforcement methods used are hydroentanglement reinforcement, needle reinforcement, and a combination of needle reinforcement and hydroentanglement reinforcement.
9. An application characterized in that, The application of the nonwoven fabric prepared by any one of the nonwoven fabric preparation methods of claims 1 to 8 in filter rods.
10. The application according to claim 9, characterized in that, Nonwoven fabrics are pleated and cut before being used in filter rods.