Preparation method and preparation device of antibacterial lyocell short cut fiber and application thereof

Abstract

This invention provides a method, equipment, and application for preparing antibacterial lyocell chopped fibers, belonging to the field of fiber production technology. The method includes the following steps: S1. Lyocell chopped fibers are uniformly sprayed with a 5%-20% NaOH solution at a temperature of 20℃-80℃, and loaded into a primary hot-pile device. The mass ratio of the dry fiber weight of the lyocell chopped fibers to the 5%-20% NaOH solution is 1:1 to 1:2. The lyocell chopped fibers with added NaOH solution are then hot-piled in a closed system at 50℃-70℃ for 1-3 hours. The non-leaching antibacterial nonwoven fabric prepared by this invention can remove preservatives and antibacterial agents from the solution, requiring only pure water or the addition of only the active ingredient. This significantly simplifies the formulation and production process, making the addition of the active ingredient easier and more stable, reducing the risk of sensitization during use, and improving the safety of the product.

Description

Technical Field

[0001] This invention relates to the field of fiber production technology, specifically to a method for preparing antibacterial lyocell short-cut fibers, preparation equipment, and their applications. Background Technology

[0002] In recent years, flushable wet toilet paper has become increasingly widely used in households. The country has successively issued relevant national standards and regulations for related industries, such as GB / T27728.1-2024 Wet wipes and similar products, GB / T41244-2022 Fluffable spunlace nonwoven materials and products, and GB / T40181-2021 Test method and evaluation of flushability of disposable sanitary nonwoven materials.

[0003] Flushable nonwoven fabric is a biodegradable, flushable nonwoven substrate designed for wet toilet paper. Its core features are sufficient strength when wet and rapid disintegration upon contact with water, allowing it to be flushed directly down the toilet without clogging pipes or polluting the environment. It is an upgraded alternative to traditional dry toilet paper and ordinary wet wipes. Currently, the mainstream materials for flushable nonwoven fabric are wood pulp and chopped regenerated cellulose fibers. Wood pulp accounts for 60%-80%, providing flushability, absorbency, and low cost, which is key to its rapid disintegration. Chopped regenerated cellulose fibers, viscose, or lyocell fibers account for 20%-40%, improving wet strength, softness, and skin-friendliness, compensating for the insufficient wet strength of pure wood pulp. The length of chopped lyocell or viscose fibers is generally between 3-12mm, providing sufficient web formation while also ensuring flushability.

[0004] To save energy and improve the production dispersion of chopped lyocell fibers, most manufacturers directly purchase wet lyocell fibers for production. However, because lyocell fibers are transported in a wet state, even with the addition of antibacterial agents, the storage time is very limited, often resulting in quality problems.

[0005] The mainstream manufacturing process of flushable nonwoven fabric is mainly wet web forming + hydroentangling. Wet web forming involves making a suspension from wood pulp and regenerated cellulose fiber short fibers. After wet web forming, it is reinforced by high-pressure water flow. There are no chemical adhesives, resulting in high softness, controllable wet strength, and excellent flushability. Fluffable nonwoven fabric is the most important raw material for wet toilet paper.

[0006] Wet toilet paper is a product made by adding a composite liquid to a flushable nonwoven fabric, including preservatives and antibacterial ingredients (natural or synthetic), and other active ingredients. It disintegrates quickly upon contact with water. Because wet toilet paper needs to be stored in damp places like bathrooms for extended periods, preservatives or antibacterial ingredients are essential in the liquid formulation to prevent bacterial growth after opening. However, even natural preservatives and antibacterial ingredients pose a significant risk of allergies, especially since wet toilet paper comes into contact with the anus or urethra. Long-term use of wet toilet paper containing preservatives and antibacterial ingredients may lead to allergic reactions. Therefore, the wet toilet paper industry aims to develop non-leaching antibacterial flushable nonwoven fabrics to ensure product storage safety while reducing the amount of preservatives and antibacterial agents in the liquid formulation. This would reduce or completely eliminate the residue of preservatives or antibacterial agents on the mucous membranes, preventing allergy risks.

[0007] The invention patent with application number 202310592755.4 discloses a biodegradable and highly effective antibacterial wet toilet paper and its production process. The solution is to prepare a wet toilet paper wetting agent solution with anti-inflammatory and antibacterial properties for the skin, replacing disinfecting ingredients such as alcohol. Then, the wet toilet paper wetting agent solution with anti-inflammatory and antibacterial properties is sprayed onto the wet toilet paper substrate to obtain antibacterial wet toilet paper.

[0008] However, the wetting agent solution added to these types of wet toilet paper may come into contact with or remain on the human mucous membranes during use, posing a certain risk of sensitization. Summary of the Invention

[0009] This invention provides a method for preparing antibacterial lyocell short-cut fibers, a preparation device, and their applications, in order to solve the technical problems in the prior art.

[0010] To address the above problems, the method for preparing antibacterial lyocell short-cut fibers provided by this invention adopts the following technical solution, including the following steps: S1. Lyocell chopped fibers are uniformly sprayed with a 5%-20% NaOH solution at a temperature of 20℃-80℃, and loaded into a primary hot-pile device. The mass ratio of the dry fiber weight of the lyocell chopped fibers to the mass of the 5%-20% NaOH solution is 1:1 to 1:2. The lyocell chopped fibers with added NaOH solution are then placed in a closed hot pile at 50℃-70℃ for 1-3 hours. S2. After hot-piling, the lyocell chopped fibers form lyocell chopped alkali cellulose. A 10%-50% aqueous solution of the cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is sprayed again at a temperature of 50℃-80℃. The mass ratio of the dry lyocell chopped fibers to the 10%-50% cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride aqueous solution is 1:0.01 to 1:0.05. The lyocell chopped alkali cellulose with the added cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride aqueous solution is then loaded into a secondary hot-piling device and hot-piled again at 50℃-80℃ for 4-8 hours. The cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is grafted onto the lyocell chopped alkali cellulose.

[0011] As a further improvement, the primary thermal reactor device includes a rotatable cylindrical insulated barrel. During the thermal reactor process, the cylindrical insulated barrel rotates at a speed of 5-10 revolutions per minute to prevent the liquid from settling. The structure of the secondary thermal reactor is the same as that of the primary thermal reactor.

[0012] As a further improvement, the inner wall of the cylindrical heat-insulating barrel is provided with spiral baffles, and the height of the spiral baffles at both ends of the cylindrical heat-insulating barrel is higher than the height of the spiral baffle at the middle position of the cylindrical heat-insulating barrel.

[0013] As a further improvement, the maximum height at both ends of the spiral baffle is 1 / 8 of the radius of the cylindrical insulation barrel, the minimum height at the middle position of the spiral baffle is 0, and the height of the spiral baffle changes linearly.

[0014] The present invention also provides an apparatus for preparing antibacterial lyocell chopped fibers, which includes an alkaline solution addition device and an antibacterial component addition device. The alkaline solution adding device includes a material conveyor belt for conveying lyocell chopped fibers, a liquid spraying mechanism for spraying liquid above the material conveyor belt, and a cylindrical insulated barrel for receiving lyocell chopped fibers below the end of the material conveyor belt. The structure of the antibacterial component addition device is the same as that of the alkaline solution addition device.

[0015] As a further improvement, the bottom of the material conveyor belt is provided with a liquid recovery hopper for receiving excess liquid. The liquid recovery hopper is connected to the liquid tank through a pipe. The liquid tank is connected to the liquid spraying mechanism through a pipe. A metering pump is also connected to the pipe between the liquid tank and the liquid spraying mechanism.

[0016] As a further improvement, the inner wall of the cylindrical heat-insulating barrel is provided with spiral baffles, and the height of the spiral baffles at both ends of the cylindrical heat-insulating barrel is higher than the height of the spiral baffle at the middle position of the cylindrical heat-insulating barrel.

[0017] As a further improvement, the maximum height at both ends of the spiral baffle is 1 / 8 of the radius of the cylindrical insulation barrel, the minimum height at the middle position of the spiral baffle is 0, and the height of the spiral baffle changes linearly.

[0018] The present invention also provides a method for preparing antibacterial lyocell chopped fibers and the application of the prepared antibacterial lyocell chopped fibers in wet toilet paper.

[0019] The application of the antibacterial lyocell chopped fibers prepared by this method in wet toilet paper includes the following steps: Lyocell chopped fibers are uniformly sprayed with a 5%-20% NaOH solution at a temperature of 20℃-80℃, and then loaded into a primary hot-pile device. The mass ratio of the dry fiber weight of the lyocell chopped fibers to the 5%-20% NaOH solution is 1:1 to 1:2. The lyocell chopped fibers with added NaOH solution are then placed in a closed hot pile at 50℃-70℃ for 1-3 hours. S2. After hot-piling, the lyocell short-cut fibers form lyocell short-cut alkali cellulose. A 10%-50% aqueous solution of the cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is sprayed again at a temperature of 50℃-80℃. The mass ratio of the dry lyocell short-cut fibers to the 10%-50% cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride aqueous solution is 1:0.01 to 1:0.05. The lyocell short-cut alkali cellulose with the added cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride aqueous solution is loaded into a secondary hot-piling device and hot-piled again at 50℃-80℃ for 4-8 hours. The cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is grafted onto the lyocell short-cut alkali cellulose. S3. Through steps S1 and S2, antibacterial lyocell short-cut cellulose grafted with cationic antibacterial reagent is obtained; S4. Take 20-30% of the antibacterial lyocell short-cut cellulose and 70-80% of the crushed wood pulp as pulp, and mix the pulp with water evenly to prepare a pulp suspension with a concentration of 0.02%-0.05%; S5. Spray the slurry suspension onto the forming screen to form a fiber web; S6. After dehydration, the fiber web is fed into a hydroentangling equipment to obtain a shaped nonwoven fabric. The hydroentangling pressure is 10 bar-50 bar. S7. After lightly pressing and drying the shaped nonwoven fabric, a non-leaching antibacterial and washable nonwoven fabric is obtained.

[0020] The beneficial effects of the above-described technical solution of the present invention are as follows: 1. The method for preparing antibacterial lyocell short-cut fibers of the present invention has high grafting efficiency and does not require the addition of preservatives or antibacterial agents during the transportation of raw materials.

[0021] Two hot-packing processes improve grafting efficiency. The first hot-packing involves mixing an alkaline solution with lyocell fibers, partially etching the smooth surface of the fibers after alkali treatment. A second hot-packing process, adding an antibacterial agent, further enhances this process. After grafting cationic antibacterial agents onto the lyocell cellulose, the orientation of the various cationic antibacterial agents becomes more pronounced, facilitating the formation of a three-dimensional cationic encapsulation structure. This structure electrostatically adsorbs and captures microorganisms near the antibacterial cellulose, then inserts hydrophobic alkyl chains into the bacterial membrane's bilayer phospholipid layer, inhibiting bacterial growth. This process achieves a grafting efficiency of over 95% between the cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride and chopped lyocell fibers. The antibacterial components are stably bound, and the hydroentangling process directly removes ungrafted antibacterial agents, eliminating the need for additional cleaning steps and reducing water and electricity consumption.

[0022] 2. The thermal stack process uses a cylindrical insulated tank that rotates continuously at a uniform speed. The cylindrical insulated tank is equipped with a spiral baffle to avoid problems such as liquid sinking, fiber entanglement, and wall adhesion. The batch processing method is simple and efficient.

[0023] 3. The wet toilet paper made from the non-leaching antibacterial nonwoven fabric prepared by this process can remove preservatives and antibacterial agents in the solution preparation. Only pure water or only the active ingredients need to be added, which greatly simplifies the formulation and production process of the solution preparation, and makes the addition of active ingredients simpler and more stable.

[0024] It eliminates the problem of preservatives / antibacterial agents in traditional wet toilet paper coming into contact with and leaving residues on the mucous membranes of the anus and urethra, greatly reducing the risk of allergies during use and improving the safety of the product.

[0025] Furthermore, the wet toilet paper prepared using this process has the same antibacterial effect as commercially available wet toilet paper with added preservatives and antibacterial agents, ensuring product storage safety while achieving a superior user experience.

[0026] 4. Lyocell chopped short fibers and non-woven fabrics have inherent antibacterial properties, reducing the risk of contamination of raw materials during transportation and storage, and improving the stability of product quality throughout the entire production process. Attached Figure Description

[0027] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein: Figure 1 This is a schematic diagram of the structure of the antibacterial lyocell short-cut fiber preparation equipment of the present invention; Figure 2 This is a schematic diagram of the cylindrical insulated barrel of the antibacterial lyocell short-cut fiber preparation equipment of the present invention; Figure 3This is a schematic diagram of the structure of lyocell short-cut fibers before alkali treatment in the preparation method of antibacterial lyocell short-cut fibers of the present invention. Figure 4 This is a schematic diagram of the structure of lyocell short-cut fibers after alkali treatment, as described in the preparation method of antibacterial lyocell short-cut fibers of the present invention. Figure 5 This is the reaction formula for the reaction of cellulose with alkali to produce alkali cellulose in this invention; Figure 6 This is the reaction formula for the formation of grafted cations from alkali cellulose and 2,3-epoxypropyltrimethylammonium chloride in this invention.

[0028] Explanation of reference numerals in the attached figures: 1. Liquid tank; 2. Metering pump; 3. Material conveyor belt; 4. Primary heat packing device; 401. Cylindrical insulated tank; 402. Spiral baffle; 5. Liquid recovery hopper; 6. Liquid spraying mechanism; 7. Wood pulp cellulose fiber; 8. Lyocell short-cut cellulose fiber. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art should understand that the embodiments described below are only some, not all, of the embodiments disclosed. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] In the existing technology, the production of wet toilet paper and its core substrate, washable nonwoven fabric, mainly suffers from the following problems: On the one hand, with the improvement of the supply chain, most manufacturers choose to directly purchase wet lyocell fibers for production, further reducing raw material costs. However, lyocell fibers transported in a wet state have a very limited storage time, even with the addition of antibacterial agents, often leading to quality problems.

[0031] On the other hand, the antibacterial and preservative properties of traditional wet toilet paper rely on adding natural or synthetic preservative and antibacterial ingredients to the solution. Since wet toilet paper comes into contact with mucous membranes such as the anus and urethra, long-term use of such products can lead to the antibacterial and preservative agents in the solution coming into contact with and remaining on the mucous membranes, posing a high risk of sensitization.

[0032] Regarding the above-mentioned problems, the concept of this invention is as follows: By modifying the substrate source, chemically modifying lyocell chopped fibers, and grafting cationic antibacterial agents onto the fibers through chemical bonds, antibacterial lyocell chopped fibers are prepared.

[0033] Traditional wet toilet paper's antibacterial approach has always been limited to the post-processing method of "adding antibacterial agents to the solution." Most manufacturers' main research and development goal is to develop antibacterial agents with natural ingredients or those that are harmless to the human body. This way, on the one hand, the impact of antibacterial agents on the human body can be reduced, and on the other hand, natural ingredients can be used as a selling point.

[0034] As an upstream raw material, improving lyocell chopped strand fiber requires consideration of fiber modification, product performance, production adaptation, and the implementation of processes, among other challenges.

[0035] In terms of process, this invention employs a two-stage thermal stacking method. The lyocell chopped fibers undergo a first thermal stacking after being sprayed with NaOH solution, resulting in partial etching of the smooth surface after alkali treatment. Then, a second thermal stacking is performed after spraying with an aqueous solution of the cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride. After alkali treatment, the surface of the lyocell chopped fibers is partially etched at random locations. After grafting with cationic antibacterial agents, the orientation differences between the various cationic antibacterial agents are more pronounced, making it easier to form a three-dimensional cationic encapsulation structure. This allows for electrostatic adsorption and capture of microorganisms near the antibacterial cellulose, followed by the insertion of hydrophobic alkyl chains into the bacterial membrane's phospholipid bilayer, inhibiting bacterial growth.

[0036] In terms of equipment, the equipment and process complement each other. The equipment must ensure better modification results while minimizing costs. This invention employs a rotatable cylindrical insulated tank 401 with a spiral baffle 402 and a liquid recycling spraying device to solve the problems of liquid sedimentation and fiber entanglement on the wall, ensuring uniform reaction between the fiber and the alkali solution and antibacterial agent. At the same time, this equipment can be directly modified on existing production lines, avoiding the difficulty in promotion due to excessive investment in production line modification.

[0037] Both the process and equipment of this invention offer relatively controllable costs. The antibacterial grafting process is integrated into the conventional nonwoven fabric production process, and the hydroentangling process can directly wash away the ungrafted antibacterial agent without additional cleaning steps. Furthermore, the production process is compatible with existing wet web laying and hydroentangling equipment, eliminating the need for large-scale equipment replacement and controlling modification costs. In addition, the antibacterial lyocell chopped fibers prepared by this process significantly reduce the risk of contamination and mold growth during transportation. Moreover, no preservatives or antibacterial agents need to be added during the subsequent preparation of wet toilet paper, ultimately achieving a cost for the finished wet toilet paper of this invention that is essentially on par with the cost of conventional wet toilet paper on the market.

[0038] After introducing the basic principles of the present invention, various non-limiting embodiments of the present invention are described in detail below. Any number of elements in the accompanying drawings is for illustrative purposes only and not for limitation, and any naming is for distinction only and has no limiting meaning.

[0039] The principles and spirit of the present invention will be explained in detail below with reference to several representative embodiments.

[0040] Example 1 of the preparation method, preparation equipment and application of antibacterial lyocell chopped fibers provided by the present invention: like Figures 1-6 As shown, the preparation method of antibacterial lyocell short-cut fibers includes the following steps: S1. Lyocell chopped fibers are uniformly sprayed with a 20% NaOH solution at 80℃ and loaded into the primary hot stack device 4. The dry fiber weight of the lyocell chopped fibers and the mass ratio of the 20% NaOH solution are 1:1. The lyocell chopped fibers with added 20% NaOH solution are then hot-stacked in a closed system at 70℃ for 1 hour. A temperature of 80°C ensures that the temperature of the chopped Lyocell fibers sprayed with NaOH solution is maintained at around 70°C when entering the primary hot-pile device 4. This temperature is essentially the same as the hot-pile temperature, eliminating the need for separate heating of the chopped Lyocell fibers within the primary hot-pile device 4. In this embodiment, the dry fiber weight to 20% NaOH solution mass ratio is 1:1, which is relatively optimal. If a NaOH solution with a concentration lower than 20% is used, the mass of the NaOH solution should be increased. This embodiment uses NaOH solution as the etching agent. In other embodiments, alkaline solutions such as KOH can be used instead, but from the perspective of cost and effectiveness, NaOH solution is a better choice. The reaction time is 1 hour at a hot-pile temperature of 70°C. When the reaction temperature decreases, the reaction time needs to be increased accordingly. The hot-pile reaction temperature is generally not lower than 50°C to avoid excessively long reaction times.

[0041] S2. After hot-piling, the lyocell chopped fibers form lyocell chopped alkali cellulose. The lyocell chopped fibers are then sprayed again with a 50% cationic antimicrobial agent, 2,3-epoxypropyltrimethylammonium chloride (GTMAC) aqueous solution at 70°C. The mass ratio of the dry lyocell chopped fibers to the 50% cationic antimicrobial agent, 2,3-epoxypropyltrimethylammonium chloride aqueous solution, is 1:0.01. The lyocell chopped alkali cellulose with the added 50% cationic antimicrobial agent, 2,3-epoxypropyltrimethylammonium chloride aqueous solution, is loaded into a secondary hot-piling device and hot-piled again at 70°C for 4-8 hours. The 50% cationic antimicrobial agent, 2,3-epoxypropyltrimethylammonium chloride aqueous solution, is then grafted onto the lyocell chopped alkali cellulose.

[0042] Because the secondary thermal reactor time is relatively long, a temperature of 70℃ is sufficient for spraying the cationic antibacterial agent. A 50% aqueous solution of 2,3-epoxypropyltrimethylammonium chloride is the optimal choice for the cationic antibacterial agent.

[0043] In this embodiment, the primary thermal reactor device 4 includes a rotatable cylindrical heat-insulating barrel 401. During the thermal reactor process, the rotation speed of the cylindrical heat-insulating barrel 401 is 5-10 revolutions / min to prevent the liquid medicine from sinking. The structure of the secondary thermal reactor is the same as that of the primary thermal reactor 4.

[0044] The inner wall of the cylindrical heat preservation barrel 401 is provided with a spiral baffle 402. The height of the spiral baffle 402 at both ends of the cylindrical heat preservation barrel 401 is higher than the height of the spiral baffle 402 in the middle of the cylindrical heat preservation barrel 401.

[0045] The maximum height at both ends of the spiral baffle 402 is 1 / 8 of the radius of the cylindrical insulation barrel 401, and the minimum height at the middle position of the spiral baffle 402 is 0. The height of the spiral baffle 402 changes linearly.

[0046] like Figure 1 and Figure 2 As shown, this embodiment also provides an apparatus for preparing antibacterial lyocell chopped fibers, which is used to prepare the above-mentioned antibacterial lyocell chopped fibers, including an alkaline solution addition device and an antibacterial component addition device; The alkaline solution addition device includes a material conveyor belt 3 for conveying lyocell chopped fibers, a liquid spraying mechanism 6 for spraying the solution above the material conveyor belt 3, and a liquid recovery hopper 5 for receiving excess solution at the bottom of the material conveyor belt 3. The liquid recovery hopper 5 is equipped with a filter structure at the bottom to prevent the solution from clogging the liquid spraying mechanism 6. The liquid recovery hopper 5 is connected to the liquid tank 1 through a pipe. A circulation pump can be installed on the pipe between the liquid recovery hopper 5 and the liquid tank 1 to ensure stable liquid return. The liquid tank 1 is connected to the liquid spraying mechanism 6 through a pipe. A metering pump 2 is also connected to the pipe between the liquid tank 1 and the liquid spraying mechanism 6. The liquid tank 1 has a built-in liquid concentration monitoring structure to monitor whether the liquid concentration is maintained at the set value.

[0047] A cylindrical insulated barrel 401 for receiving lyocell short-cut fibers is provided below the end of the material conveyor belt 3; a spiral baffle 402 is provided on the inner side wall of the cylindrical insulated barrel 401, and the height of the spiral baffle 402 at both ends of the cylindrical insulated barrel 401 is higher than the height of the spiral baffle 402 at the middle position of the cylindrical insulated barrel 401.

[0048] The cylindrical insulated barrel 401 is placed below the end of the material conveyor belt 3. After the cylindrical insulated barrel 401 is received, it is sent into the hot stacking box / room for hot stacking. During the hot stacking process, the cylindrical insulated barrel is kept rotating by external rotating equipment or rotating brackets (there are many equipment or methods that can achieve the cylindrical insulated barrel 401, and they are all existing technologies, and their structures will not be described in detail here) to prevent the liquid medicine from sinking.

[0049] The maximum height at both ends of the spiral baffle 402 is 1 / 8 of the radius of the cylindrical insulation barrel 401, and the minimum height at the middle position of the spiral baffle 402 is 0. The height of the spiral baffle 402 changes linearly.

[0050] The height of the spiral baffle 402 is about 1 / 8 of the radius of the cylindrical insulation barrel 401. The total height of the two ends of the spiral baffle 402 is about 1 / 4 of the radius of the cylindrical insulation barrel 401. This can prevent the fibers from moving and getting tangled. When the fibers are poured out for subsequent dispersion and hydroentangling processes, there will not be too much accumulation, and the manual operation of moving the fibers will be reduced.

[0051] The structure of the antibacterial component addition device is the same as that of the alkaline solution addition device. Example 2

[0052] This embodiment provides a method for preparing antibacterial lyocell short-cut fibers and their application in wet toilet paper.

[0053] The application of the antibacterial lyocell chopped fibers prepared by this method in wet toilet paper includes the following steps: S1. Lyocell chopped fibers are uniformly sprayed with a 20% NaOH solution at 80℃ and loaded into the primary hot stack device 4. The dry fiber weight of the lyocell chopped fibers and the mass ratio of the 20% NaOH solution are 1:1. The lyocell chopped fibers with added 20% NaOH solution are then hot-stacked in a closed system at 70℃ for 1 hour. S2. After hot-piling, the lyocell short-cut fibers form lyocell short-cut alkali cellulose. A 50% cationic antibacterial agent, 2,3-epoxypropyltrimethylammonium chloride (GTMAC) aqueous solution, is sprayed again at 70°C. The mass ratio of the dry lyocell short-cut fibers to the 50% cationic antibacterial agent, 2,3-epoxypropyltrimethylammonium chloride aqueous solution, is 1:0.01. The lyocell short-cut alkali cellulose with the added 50% cationic antibacterial agent, 2,3-epoxypropyltrimethylammonium chloride aqueous solution, is loaded into a secondary hot-piling device and hot-piled again at 70°C for 4-8 hours. The 50% cationic antibacterial agent, 2,3-epoxypropyltrimethylammonium chloride aqueous solution, is then grafted onto the lyocell short-cut alkali cellulose. S3. Through steps S1 and S2, antibacterial lyocell short-cut cellulose grafted with cationic antibacterial reagent is obtained; S4. Take 20-30% of the antibacterial lyocell short-cut cellulose and 70-80% of the crushed wood pulp as pulp, and mix the pulp with water evenly to prepare a pulp suspension with a concentration of 0.02%-0.05%; S5. Spray the slurry suspension onto the forming screen to form a fiber web; S6. After dehydration, the fiber web is fed into a hydroentangling equipment to obtain a shaped nonwoven fabric. The hydroentangling pressure is 10 bar-50 bar. S7. After lightly pressing and drying the shaped nonwoven fabric, a non-leaching antibacterial and washable nonwoven fabric is obtained.

[0054] like Figure 3 and Figure 4 As shown, wood pulp cellulose fiber 7 and lyocell short-cut cellulose fiber 8 are hydroentangled to form a non-leaching antibacterial washable nonwoven fabric. Since the lyocell short-cut cellulose fiber 8 is treated with alkali, its surface is partially etched and the etched parts are random. After grafting cationic antibacterial agents, the orientation of each cationic antibacterial agent is more obvious, making it easier to form a three-dimensional cationic surrounding structure. Microorganisms close to the antibacterial cellulose are captured by electrostatic adsorption, and then the hydrophobic alkyl chain is inserted into the bacterial membrane bilayer phospholipid layer to inhibit bacterial growth.

[0055] Finally, the non-leaching antibacterial and washable non-woven fabric can be mixed with a solution to form the final wet toilet paper product. The solution can be pure water or just the active ingredients. Example 3

[0056] In this comparative example, an antibacterial, washable nonwoven fabric prepared according to the method of Example 2 was mixed with 1:2 ultrapure water to obtain a non-leaching antibacterial wet toilet paper sample.

[0057] Comparative Example 1: In this comparative example, ordinary short-cut lyocell cellulose fiber was used, and its production process is as follows: wood pulp → NMMO dissolution → spinning → drawing and refining → cutting → pressing and dehydration → packaging.

[0058] The difference between this comparative example and Example 1 is that the process in Example 1 includes a modification treatment. The production process of antibacterial lyocell chopped fiber in Example 1 is as follows: wood pulp → NMMO dissolution → spinning → drawing and refining → cutting → NaOH addition → hot stacking → antibacterial component addition → hot stacking → pressing and dehydration → packaging.

[0059] Comparative Example 2 This comparative example is a typical washable nonwoven fabric sample, whose preparation process includes the following steps: S1. Mix ordinary short-chopped lyocell cellulose fibers, 70-80% crushed wood pulp, and water evenly to make a pulp with a concentration of 0.02%-0.05%; S2 sprays a suspension of wood pulp containing ordinary short-cut cellulose and pulverized wood onto a forming screen to form a fiber web; S3. After dehydration, the fiber web is fed into a hydroentangling equipment to obtain a shaped nonwoven fabric. The hydroentangling pressure is 10 bar-50 bar. S4. After lightly pressing and drying the shaped nonwoven fabric, a sample of ordinary washable nonwoven fabric is obtained.

[0060] Comparative Example 3 In this comparative example, a common flushable nonwoven toilet paper sample was prepared by adding ultrapure water at a ratio of 1:2 to the flushable nonwoven fabric prepared according to the method of Comparative Example 1.

[0061] Comparative Example 4 This comparative example uses commercially available wet toilet paper samples. The flushable nonwoven fabric prepared according to the method of Comparative Example 1 is mixed with a 1:2 wet toilet paper solution (containing 10ppm benzalkonium chloride, 10ppm cetylpyridinium chloride, and 10ppm methylparaben) to prepare the sample of commercially available flushable nonwoven wet toilet paper.

[0062] The preservation challenge test was conducted with reference to the European Pharmacopoeia preservation challenge test.

[0063] sample Anti-corrosion challenge test results Example 1 pass Example 2 pass Example 3 pass Comparative Example 1 Not approved Comparative Example 2 Not approved Comparative Example 3 Not approved Comparative Example 4 pass The results of the anti-corrosion challenge test show that the flushable nonwoven fabric of Example 2, made with lyocell fibers grafted with cationic antibacterial agents, and the preservative-free wet toilet paper of Example 3, prepared from Example 2, passed the anti-corrosion challenge, achieving the same anti-corrosion effect as the commercially available wet toilet paper of Comparative Example 4, which uses a preservative-added solution. However, the ordinary flushable nonwoven fabric of Comparative Example 2, which was not grafted with antibacterial agents, and the wet toilet paper of Comparative Example 3, which only added pure water, failed the anti-corrosion test.

[0064] The cleaning solution of the grafted cationic antibacterial agent in Example 1 was collected, and the total amount of 2,3-epoxypropyltrimethylammonium chloride (GTMAC) in the cleaning solution was tested and compared with the added 2,3-epoxypropyltrimethylammonium chloride (GTMAC). The grafting rate of the cationic antibacterial agent was calculated using the following formula: Grafting rate = (W) 添加的GTMAC含量 -W 清洗液中GTMAC含量 ) / W 添加的GTMAC含量 *100% Multiple samples 1 were obtained by repeatedly using the preparation method in Example 1, and the average grafting efficiency was measured to be above 95%.

[0065] The non-leaching bactericidal effect of wet toilet paper samples was compared with that of GB15979 E6.6.

[0066] The test results are as follows: sample E. coli sterilization rate / % Staphylococcus aureus sterilization rate / % Candida albicans sterilization rate / % Comparative Example 3 ＜23% ＜23% ＜23% Example 3 ＞90% ＞90% ＞90% While various embodiments of the invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of the invention. The appended claims are intended to define the scope of the invention and therefore cover any modular compositions, equivalents, or alternatives within the scope of these claims.

Claims

1. A process for the production of antibacterial lyocell staple fibers, characterized in that, Includes the following steps: S1. Lyocell chopped fibers are uniformly sprayed with a 5%-20% NaOH solution at a temperature of 20℃-80℃ and loaded into the primary hot stack device (4). The mass ratio of the dry fiber weight of the lyocell chopped fibers to the mass of the 5%-20% NaOH solution is 1:1 to 1:

2. The lyocell chopped fibers with added NaOH solution are then placed in a closed hot stack at 50℃-70℃ for 1h-3h. S2. After hot-piling, the lyocell chopped fibers form lyocell chopped alkali cellulose. A 10%-50% aqueous solution of the cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is sprayed again at a temperature of 50℃-80℃. The mass ratio of the dry lyocell chopped fibers to the 10%-50% aqueous solution of the cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is 1:0.01 to 1:0.

05. The lyocell chopped alkali cellulose with the added cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is loaded into a secondary hot-piling device and hot-piled again at 50℃-80℃ for 4-8 hours. The cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is grafted onto the lyocell chopped alkali cellulose.

2. The process for the production of antibacterial lyocell staple fibers according to claim 1, characterized in that The primary thermal reactor device (4) includes a rotatable cylindrical heat-insulating barrel (401). During the thermal reactor process, the rotation speed of the cylindrical heat-insulating barrel (401) is 5-10 revolutions / min to prevent the liquid medicine from sinking. The structure of the secondary thermal reactor is the same as that of the primary thermal reactor (4).

3. The process for the production of antibacterial lyocell staple fibers according to claim 2, characterized in that: The inner wall of the cylindrical heat-insulating barrel (401) is provided with a spiral baffle (402), and the height of the spiral baffle (402) at both ends of the cylindrical heat-insulating barrel (401) is higher than the height of the spiral baffle (402) at the middle position of the cylindrical heat-insulating barrel (401).

4. The method for preparing antibacterial lyocell short-cut fibers according to claim 3, characterized in that: The maximum height at both ends of the spiral baffle (402) is 1 / 8 of the radius of the cylindrical heat preservation barrel (401), and the minimum height at the middle position of the spiral baffle (402) is 0. The height of the spiral baffle (402) changes linearly.

5. An apparatus for preparing antibacterial lyocell chopped fibers, characterized in that: Includes an alkaline solution addition device and an antibacterial component addition device; The alkaline solution addition device includes a material conveyor belt (3) for conveying lyocell chopped fibers, a liquid spraying mechanism (6) for spraying liquid is provided above the material conveyor belt (3), and a cylindrical insulated barrel (401) for receiving lyocell chopped fibers is provided below the end of the material conveyor belt (3). The structure of the antibacterial component addition device is the same as that of the alkaline solution addition device.

6. The apparatus for preparing antibacterial lyocell chopped fibers according to claim 5, characterized in that: The bottom of the material conveyor belt (3) is provided with a liquid recovery hopper (5) for receiving excess liquid. The liquid recovery hopper (5) is connected to the liquid tank (1) through a pipe. The liquid tank (1) is connected to the liquid spraying mechanism (6) through a pipe. A metering pump (2) is also connected to the pipe between the liquid tank (1) and the liquid spraying mechanism (6).

7. The apparatus for preparing antibacterial lyocell chopped fibers according to claim 5, characterized in that: The inner wall of the cylindrical heat-insulating barrel (401) is provided with a spiral baffle (402), and the height of the spiral baffle (402) at both ends of the cylindrical heat-insulating barrel (401) is higher than the height of the spiral baffle (402) at the middle position of the cylindrical heat-insulating barrel (401).

8. The apparatus for preparing antibacterial lyocell chopped fibers according to claim 7, characterized in that: The maximum height at both ends of the spiral baffle (402) is 1 / 8 of the radius of the cylindrical heat preservation barrel (401), and the minimum height at the middle position of the spiral baffle (402) is 0. The height of the spiral baffle (402) changes linearly.

9. The application of antibacterial lyocell chopped fibers prepared by the method of any one of claims 1 to 4 in wet toilet paper.

10. The application of antibacterial lyocell chopped fibers prepared by the method for preparing antibacterial lyocell chopped fibers according to claim 9 in wet toilet paper, characterized in that, Includes the following steps: S1. Lyocell chopped fibers are uniformly sprayed with a 5%-20% NaOH solution at a temperature of 20℃-80℃ and loaded into the primary hot stack device (4). The mass ratio of the dry fiber weight of the lyocell chopped fibers to the mass of the 5%-20% NaOH solution is 1:1 to 1:

2. The lyocell chopped fibers with added NaOH solution are then placed in a closed hot stack at 50℃-70℃ for 1h-3h. S2. After hot-piling, the lyocell short-cut fibers form lyocell short-cut alkali cellulose. A 10%-50% aqueous solution of the cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is sprayed again at a temperature of 50℃-80℃. The mass ratio of the dry lyocell short-cut fibers to the 10%-50% cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride aqueous solution is 1:0.01 to 1:0.

05. The lyocell short-cut alkali cellulose with the added cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride aqueous solution is loaded into a secondary hot-piling device and hot-piled again at 50℃-80℃ for 4-8 hours. The cationic antibacterial agent 2,3-epoxypropyltrimethylammonium chloride is grafted onto the lyocell short-cut alkali cellulose. S3. Through steps S1 and S2, antibacterial lyocell short-cut cellulose grafted with cationic antibacterial reagent is obtained; S4. Take 20-30% of the antibacterial lyocell short-cut cellulose and 70-80% of the crushed wood pulp as pulp, and mix the pulp with water evenly to prepare a pulp suspension with a concentration of 0.02%-0.05%; S5. Spray the slurry suspension onto the forming screen to form a fiber web; S6. After dehydration, the fiber web is fed into a hydroentangling equipment to obtain a shaped nonwoven fabric. The hydroentangling pressure is 10 bar-50 bar. S7. After lightly pressing and drying the shaped nonwoven fabric, a non-leaching antibacterial and washable nonwoven fabric is obtained.

Images