Tea bag type insertable sanitary tampon and method of making the same

Abstract

This invention discloses a tea bag-shaped finger-insertion tampon and its preparation method, belonging to the field of hygiene product technology. This invention pre-treats cotton fibers, increases the weight and density of the cotton fiber layer, and combines this with a high-compression molding process to ensure the tampon maintains its shape and does not unravel, significantly improving its morphological stability. The tea bag-shaped finger-insertion tampon is an optimization of conventional finger-insertion tampons, better conforming to the human body's physiological structure, reducing the risk of displacement during use, enhancing anti-fall-off effects, ensuring smooth insertion, good fit, and high hygiene and safety. Simultaneously, the increased fiber weight not only improves compression and shape retention but also further increases absorbency, ensuring higher absorbency and reliability in actual use.

Description

Technical Field

[0001] This invention relates to the field of hygiene products technology, specifically to a tea bag-shaped finger-insertion tampons and its preparation method. Background Technology

[0002] Tampons are menstrual hygiene products inserted into the vagina. They are primarily made of highly absorbent fiber material and are used to absorb menstrual blood. Compared to traditional sanitary napkins, tampons have advantages such as small size, portability, reduced leakage when used internally, and no stuffiness during use, meeting the needs of women to swim, exercise, and engage in other daily activities during menstruation. Currently, tampons on the market are mainly divided into two types: applicator tampons and finger-insertion tampons. Applicator tampons are inserted using an external plastic or paper applicator, while finger-insertion tampons eliminate the applicator structure and require the user to insert them directly with their fingers.

[0003] Tea bag-shaped tampons, named for their tea bag-like shape, typically wrap the absorbent fiber in a non-woven, water-permeable material, leaving a tether at the end. This type of tampon eliminates the need for an applicator, reducing non-biodegradable waste and making it more environmentally friendly. It also boasts lower manufacturing costs and a simpler structure. However, existing tea bag-shaped tampons still have some technical shortcomings in production and use. First, commercially available cotton fibers naturally have waxy coatings on their surface, and in early spinning and carding processes, some softening agents were often left behind to reduce static electricity. These substances not only give the fibers some water repellency but also high elasticity. Tadpoles need to maintain a compact, high-density cylindrical shape during insertion to reduce friction, but existing fibers have extremely high resilience after compression molding and a high deformation recovery rate, resulting in poor shape retention. This makes them prone to expansion and loosening inside the packaging or upon initial contact with the body, increasing insertion difficulty and severely impacting user comfort and fit. Secondly, as an internal sanitary product, the enclosed environment after menstrual blood absorption is prone to bacterial growth. Conventional methods of physical mixing or surface coating with antibacterial agents have weak binding force, making it difficult to impart a long-lasting and stable antibacterial effect to the absorbent while maintaining the absorbency of the fibers themselves. Therefore, how to treat cotton fibers to effectively reduce their rebound tendency after compression, improve the compression and shape retention of tampons, and endow them with excellent hygienic properties is a problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The main objective of this invention is to provide a tea bag-shaped finger-insertion tampon with low resilience, high absorbency, long-lasting antibacterial properties, and excellent comfort, in order to meet the market demand for high-performance and environmentally friendly menstrual products.

[0005] To achieve the above objectives, this invention proposes a method for preparing a tea bag-shaped finger-insertion tampon, comprising the following steps:

[0006] S1. The pretreated cotton fibers are combed and laid into a single layer of cotton fibers after combing. Then, the single layer of cotton fibers is stacked, composite and shaped, and cut to obtain a cotton fiber layer. The cotton fiber layer is wrapped with non-woven fabric and then pressed into a strip fiber layer.

[0007] S2. Fix the cotton thread in the center of the strip fiber layer, with the end of the cotton thread exposed 10-20cm outside the strip fiber layer. Then, roll the strip fiber layer to form a long cylindrical absorbent body. After pressing and shaping in the forming device, microwave heating treatment is performed to obtain the tampon body.

[0008] S3. Wrap the tampon body from the side with packaging film and glue the two ends to obtain a tea bag-shaped finger-insertion tampon.

[0009] Preferably, the basis weight of the single-layer cotton fiber in step S1 is 12-16 g / m². 2 .

[0010] Preferably, the basis weight of the cotton fiber layer in step S1 is 600-1600 g / m². 2 .

[0011] Preferably, the method for preparing the pretreated cotton fibers includes the following steps:

[0012] (1) Disperse cotton fibers in an aqueous sodium hydroxide solution, add a wetting agent, heat and stir, cool, remove the cotton fibers, wash with water until the filtrate is neutral, and then dry to obtain refined cotton fibers;

[0013] (2) Take refined cotton fiber and react it with 2,3-epoxypropyltrimethylammonium chloride under alkaline conditions. Take out the fiber, wash it with water and then dry it to obtain cationic cotton fiber.

[0014] (3) Take refined cotton fiber, sodium hydroxide aqueous solution and ethanol aqueous solution, mix and stir evenly, add monochloroacetic acid, heat and react, after the reaction is completed, cool, take out the fiber, wash with water and then dry to obtain anionized cotton fiber;

[0015] (4) Equal masses of cationic cotton fibers and anionic cotton fibers are dry-opened to obtain mixed fibers. Then, ethylene glycol diglycidyl ether and sodium hydroxide are dissolved in a mixed solvent of isopropanol / water to prepare a crosslinking impregnation solution. The above mixed fibers are added to the crosslinking impregnation solution and heated to react. After the reaction is completed, the fibers are taken out, washed, dehydrated and dried to obtain pretreated cotton fibers.

[0016] Based on the above technical solutions, preferably, in step (1), the concentration of the sodium hydroxide aqueous solution is 2-5 wt%, the heating and stirring temperature is 85-95℃, and the time is 45-60 min; the wetting agent is at least one of fatty alcohol polyoxyethylene ether, sodium dodecyl sulfate, Tween-20, Tween-80, and alkyl glycoside; the amount of the wetting agent is 0.3-0.6% of the mass of the sodium hydroxide aqueous solution.

[0017] Cotton fibers naturally contain waxes, and in the early spinning / carding processes, factories often added softeners to reduce static electricity and friction. However, softeners also impart elasticity and water repellency to the fibers. This step involves refining commercially available cotton fibers. On the one hand, under heating and stirring conditions, NaOH can effectively saponify and hydrolyze the softeners remaining on the surface of the cotton fibers during processing, converting them into soluble substances that dissolve with the alkali solution. On the other hand, the wetting agent significantly reduces the surface tension of the alkali solution, allowing the NaOH solution to quickly and evenly penetrate into the capillary structure inside the cotton fibers. This ensures sufficient contact and reaction between the alkali solution and impurities in the fibers, exposing more active groups and providing active sites for subsequent anionization and cationization modification reactions.

[0018] Based on the above technical solutions, preferably, in step (2), the mass ratio of refined cotton fiber to 2,3-epoxypropyltrimethylammonium chloride is 1:0.2-0.5; the stirring reaction temperature is 55-65℃, and the reaction time is 1.5-2.5h.

[0019] In this step, the hydroxyl groups in the refined cotton fiber molecules undergo a ring-opening reaction with the epoxy groups in 2,3-epoxypropyltrimethylammonium chloride, generating new active hydroxyl groups. This introduces the cationic compound 2,3-epoxypropyltrimethylammonium chloride onto the refined cotton fiber molecules. 2,3-epoxypropyltrimethylammonium chloride is permanently grafted onto the cellulose backbone in the form of covalent bonds, giving the refined cotton fiber a positive charge and endowing it with long-lasting antibacterial properties.

[0020] Based on the above technical solutions, preferably, in step (3), the mass ratio of refined cotton fiber to monochloroacetic acid is 1:0.5-0.8; the heating reaction temperature is 60-70℃, and the reaction time is 1-1.5h.

[0021] In this step, the refined cotton fibers are carboxymethylated, thereby introducing active carboxyl groups on the surface of the cotton fibers, which is beneficial to subsequent reactions.

[0022] Based on the above technical solutions, preferably, the moisture content of cationic cotton fiber and anionic cotton fiber in step (4) is ≤8%.

[0023] In this step, controlling the moisture content of the cotton fibers is beneficial for the smooth opening process. If the moisture content is too high, electrostatic attraction will be triggered before mixing, causing local entanglement of fibers, which will destroy the uniform dispersion of anionic and cationic fibers and ultimately lead to uneven charge distribution inside the cotton sliver, affecting the resilience of the cotton fiber layer.

[0024] Based on the above technical solutions, preferably, in step (4), the total mass ratio of cationic cotton fiber and anionic cotton fiber to ethylene glycol diglycidyl ether and NaOH is 100:20-30:5-8; the heating reaction temperature is 60-80℃ and the reaction time is 2-4h.

[0025] In this step, the cationic and anionic cotton fibers are covalently bridged and fixed to form a cross-linked network through the cross-linking effect of ethylene glycol diglycidyl ether. This restricts the relative slippage freedom between the fibers. The electrostatic attraction between the carboxyl negative charge on the surface of the anionic cotton fiber and the quaternary ammonium salt group on the surface of the cationic cotton fiber further provides additional constraint at the fiber cross-linking nodes. Together with the co-cross-linked network, they suppress the fiber rebound tendency of the cotton sliver after compression, thereby effectively reducing the elasticity of the cotton sliver. This allows the cotton sliver to maintain a low deformation recovery rate after compression deformation, improving the compression shape retention of the cotton sliver and enhancing its fit and comfort during actual use.

[0026] Preferably, the microwave heating temperature in step S2 is 50-65°C, and the microwave heating time is 2-8 seconds.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1) This invention pre-treats cotton fibers, increases the weight and density of the cotton fiber layer, and combines it with a high compression molding process to make the tampons hold their shape for a long time without falling apart, significantly improving the shape stability of the tampons. The tea bag-shaped finger-insertion tampons are optimized for conventional finger-insertion tampons, better conforming to the physiological structure of the human body, reducing the risk of displacement during use, enhancing the anti-fall effect, and ensuring a smooth insertion process with good fit and high hygiene and safety. At the same time, the increased fiber weight not only improves the compression and shape retention but also further increases the absorbency, ensuring that the tampons have higher absorbency and reliability in actual use.

[0029] 2) The pre-treated cotton fiber of this invention is prepared by sequentially refining, cationizing, anionizing, and cross-linking modification of cotton fiber. The refining process removes surface waxes and residual softeners from the cotton fiber, followed by cationizing and anionizing modification. Finally, a stable three-dimensional network structure is formed by cross-linking with ethylene glycol diglycidyl ether. This structure strongly binds the fiber through covalent cross-linking and electrostatic attraction, allowing the tampon to maintain a tight cylindrical shape after compression molding. This significantly reduces the fiber's resilience and ensures that the tampon maintains a stable shape before packaging and use, solving the problem of easy expansion and loosening of traditional finger-insertion tampons. At the same time, when the tampon comes into contact with menstrual blood, liquid penetration weakens the electrostatic interaction between fibers, causing the three-dimensional network to relax appropriately, ensuring that the tampon can still fully expand and perform its liquid absorption function. Detailed Implementation

[0030] To avoid unnecessary details, unless otherwise specified, all items used in the following examples are commercially available products, and all methods used are conventional methods unless otherwise specified.

[0031] A method for preparing a tea bag-type finger-insertion tampon includes the following steps:

[0032] S1. The pre-treated cotton fibers are combed, and after combing, they are laid out to a weight of 14g / m². 2 The single-layer cotton fibers were then layered, composited, and shaped before being cut to obtain a product with a basis weight of 1400 g / m². 2 The cotton fiber layer is wrapped with non-woven fabric and then pressed into strip-shaped fiber layers.

[0033] S2. Fix the cotton thread to the center of the strip fiber layer, with the end of the cotton thread exposed 15cm outside the strip fiber layer. Then, roll the strip fiber layer to form a long cylindrical absorbent body. After pressing it in the forming device with a pressure of 1MPa, microwave heating treatment is performed. The microwave heating temperature is 58℃ and the heating time is 5s to obtain the tampon body.

[0034] S3. Wrap the tampon body from the side with PE packaging film and glue both ends to obtain a tea bag-shaped finger-insertion tampon.

[0035] The method for preparing the pretreated cotton fibers includes the following steps:

[0036] (1) Disperse 300g of cotton fiber into 5L of sodium hydroxide aqueous solution with a concentration of 3wt%, add 21g of fatty alcohol polyoxyethylene ether as a wetting agent, heat and stir at 90℃ for 50min, cool to room temperature and take out the cotton fiber, wash repeatedly with deionized water until the pH of the washing solution is neutral, and dry at 80℃ to obtain refined cotton fiber.

[0037] (2) Take 100g of refined cotton fiber and 30g of 2,3-epoxypropyltrimethylammonium chloride and add them to 500mL of sodium hydroxide aqueous solution with a concentration of 8wt%. Stir and react at 60℃ for 2h. After the reaction is completed, take out the fiber, wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain cationic cotton fiber.

[0038] (3) Take 100g of refined cotton fiber and add it to a mixed solution consisting of 200mL of 15wt% sodium hydroxide aqueous solution and 300mL of 70wt% ethanol aqueous solution. Mix and stir evenly, add 60g of monochloroacetic acid, heat and react at 65℃ for 1.2h, cool to room temperature after the reaction is completed, take out the fiber and wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain anionized cotton fiber;

[0039] (4) The cationic cotton fiber and the anionic cotton fiber were dried at 80°C to a moisture content of ≤8%. 100g of cationic cotton fiber and 100g of anionic cotton fiber were dry-opened to obtain 200g of mixed fiber. 50g of ethylene glycol diglycidyl ether and 12g of NaOH were dissolved in an appropriate amount of isopropanol / water (volume ratio 1:1) mixed solvent to prepare a crosslinking impregnation solution. The above 200g of mixed fiber was added to the crosslinking impregnation solution and reacted at 70°C for 3h. After the reaction was completed, the fiber was taken out, washed thoroughly with deionized water, dehydrated and dried at 80°C to obtain pretreated cotton fiber.

[0040] Example 2

[0041] A method for preparing a tea bag-type finger-insertion tampon includes the following steps:

[0042] S1. The pretreated cotton fibers are combed and laid into a single layer of cotton fibers with a weight of 12g / m². The single layer of cotton fibers is then stacked, composite and shaped, and cut to obtain a cotton fiber layer with a weight of 600g / m². The cotton fiber layer is wrapped with non-woven fabric and then pressed into a strip fiber layer.

[0043] S2. Fix the cotton thread to the center of the strip fiber layer, with the end of the cotton thread exposed 10cm outside the strip fiber layer. Then, roll the strip fiber layer to form a long cylindrical absorbent body. After pressing it in the forming device with a pressure of 1MPa, microwave heating treatment is performed. The microwave heating temperature is 50℃ and the heating time is 2s to obtain the tampon body.

[0044] S3. Wrap the tampon body from the side with packaging film and glue the two ends to obtain a tea bag-shaped finger-insertion tampon.

[0045] The method for preparing the pretreated cotton fibers includes the following steps:

[0046] (1) Disperse 300g of cotton fiber into 5L of sodium hydroxide aqueous solution with a concentration of 2wt%, add 20g of sodium dodecyl sulfate as a wetting agent, heat and stir at 85℃ for 45min, cool to room temperature and take out the cotton fiber, wash repeatedly with deionized water until the pH of the washing solution is neutral, and dry at 80℃ to obtain refined cotton fiber.

[0047] (2) Take 100g of refined cotton fiber and 60g of 2,3-epoxypropyltrimethylammonium chloride and add them to 500mL of sodium hydroxide aqueous solution with a concentration of 8wt%. Stir and react at 55℃ for 1.5h. After the reaction is completed, take out the fiber, wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain cationic cotton fiber.

[0048] (3) Take 100g of refined cotton fiber and add it to a mixed solution consisting of 200mL of 15wt% sodium hydroxide aqueous solution and 300mL of 70wt% ethanol aqueous solution. Mix and stir evenly, add 50g of monochloroacetic acid, heat and react at 60℃ for 1h, cool to room temperature after the reaction is completed, take out the fiber and wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain anionized cotton fiber.

[0049] (4) The cationic cotton fiber and the anionic cotton fiber were dried at 80°C to a moisture content of ≤8%. 100g of cationic cotton fiber and 100g of anionic cotton fiber were dry-opened to obtain 200g of mixed fiber. 40g of ethylene glycol diglycidyl ether and 10g of NaOH were dissolved in an appropriate amount of isopropanol / water (volume ratio 1:1) mixed solvent to prepare a crosslinking impregnation solution. The above 200g of mixed fiber was added to the crosslinking impregnation solution and reacted at 60°C for 2h. After the reaction was completed, the fiber was taken out, washed thoroughly with deionized water, dehydrated and dried at 80°C to obtain pretreated cotton fiber.

[0050] Example 3

[0051] A method for preparing a tea bag-type finger-insertion tampon includes the following steps:

[0052] S1. The pretreated cotton fibers are combed and laid into a single layer of cotton fibers with a weight of 16g / m². The single layer of cotton fibers is then stacked, composite and shaped, and cut to obtain a cotton fiber layer with a weight of 1600g / m². The cotton fiber layer is wrapped with non-woven fabric and then pressed into a strip fiber layer.

[0053] S2. Fix the cotton thread to the center of the strip fiber layer, with the end of the cotton thread exposed 20cm outside the strip fiber layer. Then, roll the strip fiber layer to form a long cylindrical absorbent body. After pressing it in the forming device with a pressure of 1MPa, microwave heating treatment is performed. The microwave heating temperature is 65℃ and the heating time is 8s to obtain the tampon body.

[0054] S3. Wrap the tampon body from the side with packaging film and glue the two ends to obtain a tea bag-shaped finger-insertion tampon.

[0055] The method for preparing the pretreated cotton fibers includes the following steps:

[0056] (1) Disperse 300g of cotton fiber into 5L of 5wt% sodium hydroxide aqueous solution, add 23g of alkyl glycoside as wetting agent, heat and stir at 95℃ for 60min, cool to room temperature and take out the cotton fiber, wash repeatedly with deionized water until the pH of the washing solution is neutral, and dry at 80℃ to obtain refined cotton fiber.

[0057] (2) Take 100g of refined cotton fiber and 80g of 2,3-epoxypropyltrimethylammonium chloride and add them to 500mL of sodium hydroxide aqueous solution with a concentration of 8wt%. Stir and react at 65℃ for 2.5h. After the reaction is completed, take out the fiber, wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain cationic cotton fiber.

[0058] (3) Take 100g of refined cotton fiber and add it to a mixed solution of 200mL of 15wt% sodium hydroxide aqueous solution and 300mL of 70wt% ethanol aqueous solution. Mix and stir evenly, add 80g of monochloroacetic acid, heat and react at 70℃ for 1.5h, cool to room temperature after the reaction is completed, take out the fiber and wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain anionized cotton fiber;

[0059] (4) The cationic cotton fiber and the anionic cotton fiber were dried at 80°C to a moisture content of ≤8%. 100g of cationic cotton fiber and 100g of anionic cotton fiber were dry-opened to obtain 200g of mixed fiber. 60g of ethylene glycol diglycidyl ether and 16g of NaOH were dissolved in an appropriate amount of isopropanol / water (volume ratio 1:1) mixed solvent to prepare a crosslinking impregnation solution. The above 200g of mixed fiber was added to the crosslinking impregnation solution and reacted at 80°C for 4h. After the reaction was completed, the fiber was taken out, washed thoroughly with deionized water, dehydrated and dried at 80°C to obtain pretreated cotton fiber.

[0060] Comparative Example 1

[0061] A method for preparing a tea bag-type finger-insertion tampon includes the following steps:

[0062] S1. The pre-treated cotton fibers are combed, and after combing, they are laid out to a weight of 14g / m². 2 The single-layer cotton fibers were then layered, composited, and shaped before being cut to obtain a product with a basis weight of 1400 g / m². 2 The cotton fiber layer is wrapped with non-woven fabric and then pressed into strip-shaped fiber layers.

[0063] S2. Fix the cotton thread to the center of the strip fiber layer, with the end of the cotton thread exposed 15cm outside the strip fiber layer. Then, roll the strip fiber layer to form a long cylindrical absorbent body. After pressing it in the forming device with a pressure of 1MPa, microwave heating treatment is performed. The microwave heating temperature is 58℃ and the heating time is 5s to obtain the tampon body.

[0064] S3. Wrap the tampon body from the side with PE packaging film and glue both ends to obtain a tea bag-shaped finger-insertion tampon.

[0065] The method for preparing the pretreated cotton fibers includes the following steps:

[0066] (1) Take 100g of commercially available cotton fiber and 30g of 2,3-epoxypropyltrimethylammonium chloride and add them to 500mL of sodium hydroxide aqueous solution with a concentration of 8wt%. Stir and react at 60℃ for 2h. After the reaction is completed, take out the fiber, wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain cationic cotton fiber.

[0067] (2) Take 100g of commercially available cotton fiber and add it to a mixed solution consisting of 200mL of 15wt% sodium hydroxide aqueous solution and 300mL of 70wt% ethanol aqueous solution. Mix and stir evenly, add 60g of monochloroacetic acid, heat and react at 65℃ for 1.2h, cool to room temperature after the reaction is completed, take out the fiber and wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain anionized cotton fiber;

[0068] (3) The cationic cotton fiber and the anionic cotton fiber were dried at 80°C to a moisture content of ≤8%. 100g of cationic cotton fiber and 100g of anionic cotton fiber were dry-opened to obtain 200g of mixed fiber. 50g of ethylene glycol diglycidyl ether and 12g of NaOH were dissolved in an appropriate amount of isopropanol / water (volume ratio 1:1) mixed solvent to prepare a crosslinking impregnation solution. The above 200g of mixed fiber was added to the crosslinking impregnation solution and reacted at 70°C for 3h. After the reaction was completed, the fiber was taken out, washed thoroughly with deionized water, dehydrated and dried at 80°C to obtain pretreated cotton fiber.

[0069] The difference between Comparative Example 1 and Example 1 is that the cotton fibers were not refined, but were directly modified by anionization and crosslinking of commercially available cotton fibers.

[0070] Comparative Example 2

[0071] A method for preparing a tea bag-type finger-insertion tampon includes the following steps:

[0072] S1. The pre-treated cotton fibers are combed, and after combing, they are laid out to a weight of 14g / m². 2 The single-layer cotton fibers were then layered, composited, and shaped before being cut to obtain a product with a basis weight of 1400 g / m². 2 The cotton fiber layer is wrapped with non-woven fabric and then pressed into strip-shaped fiber layers.

[0073] S2. Fix the cotton thread to the center of the strip fiber layer, with the end of the cotton thread exposed 15cm outside the strip fiber layer. Then, roll the strip fiber layer to form a long cylindrical absorbent body. After pressing it in the forming device with a pressure of 1MPa, microwave heating treatment is performed. The microwave heating temperature is 58℃ and the heating time is 5s to obtain the tampon body.

[0074] S3. Wrap the tampon body from the side with PE packaging film and glue both ends to obtain a tea bag-shaped finger-insertion tampon.

[0075] The method for preparing the pretreated cotton fibers includes the following steps:

[0076] (1) Disperse 300g of cotton fiber into 5L of sodium hydroxide aqueous solution with a concentration of 3wt%, add 21g of fatty alcohol polyoxyethylene ether as a wetting agent, heat and stir at 90℃ for 50min, cool to room temperature and take out the cotton fiber, wash repeatedly with deionized water until the pH of the washing solution is neutral, and dry at 80℃ to obtain refined cotton fiber.

[0077] (2) Dry the refined cotton fiber at 80°C until the moisture content is ≤8%, take 200g of refined cotton fiber and dry open it to obtain open cotton fiber; dissolve 50g of ethylene glycol diglycidyl ether and 12g of NaOH in an appropriate amount of isopropanol / water (volume ratio 1:1) mixed solvent to prepare a crosslinking impregnation solution; add the above 200g of open cotton fiber to the crosslinking impregnation solution and react at 70°C for 3h. After the reaction is completed, take out the fiber, wash it thoroughly with deionized water, dehydrate it and dry it at 80°C to obtain pretreated cotton fiber.

[0078] The difference between Comparative Example 2 and Example 1 is that the cotton fibers are directly cross-linked after only refining.

[0079] Comparative Example 3

[0080] A method for preparing a tea bag-type finger-insertion tampon includes the following steps:

[0081] S1. The pre-treated cotton fibers are combed, and after combing, they are laid out to a weight of 14g / m². 2 The single-layer cotton fibers were then layered, composited, and shaped before being cut to obtain a product with a basis weight of 1400 g / m². 2 The cotton fiber layer is wrapped with non-woven fabric and then pressed into strip-shaped fiber layers.

[0082] S2. Fix the cotton thread to the center of the strip fiber layer, with the end of the cotton thread exposed 15cm outside the strip fiber layer. Then, roll the strip fiber layer to form a long cylindrical absorbent body. After pressing it in the forming device with a pressure of 1MPa, microwave heating treatment is performed. The microwave heating temperature is 58℃ and the heating time is 5s to obtain the tampon body.

[0083] S3. Wrap the tampon body from the side with PE packaging film and glue both ends to obtain a tea bag-shaped finger-insertion tampon.

[0084] The method for preparing the pretreated cotton fibers includes the following steps:

[0085] (1) Disperse 300g of cotton fiber into 5L of sodium hydroxide aqueous solution with a concentration of 3wt%, add 21g of fatty alcohol polyoxyethylene ether as a wetting agent, heat and stir at 90℃ for 50min, cool to room temperature and take out the cotton fiber, wash repeatedly with deionized water until the pH of the washing solution is neutral, and dry at 80℃ to obtain refined cotton fiber.

[0086] (1) Take 100g of refined cotton fiber and 30g of 2,3-epoxypropyltrimethylammonium chloride and add them to 500mL of sodium hydroxide aqueous solution with a concentration of 8wt%. Stir and react at 60℃ for 2h. After the reaction is completed, take out the fiber, wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain cationic cotton fiber.

[0087] (2) Take 100g of refined cotton fiber and add it to a mixed solution consisting of 200mL of 15wt% sodium hydroxide aqueous solution and 300mL of 70wt% ethanol aqueous solution. Mix and stir evenly, add 60g of monochloroacetic acid, heat and react at 65℃ for 1.2h, cool to room temperature after the reaction is completed, take out the fiber and wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain anionized cotton fiber;

[0088] (4) The cationic cotton fiber and the anionic cotton fiber are dried at 80°C to a moisture content of ≤8%. 100g of cationic cotton fiber and 100g of anionic cotton fiber are dry-opened and mixed, and then directly dehydrated and dried to obtain pretreated cotton fiber.

[0089] The difference between Comparative Example 3 and Example 1 is that the anionic and cationic mixed fibers were not cross-linked with ethylene glycol diglycidyl ether, and there was only electrostatic attraction between the fibers without a covalent cross-linking network.

[0090] Comparative Example 4

[0091] A method for preparing a tea bag-type finger-insertion tampon includes the following steps:

[0092] S1. The pre-treated cotton fibers are combed, and after combing, they are laid out to a weight of 14g / m². 2 The single-layer cotton fibers were then layered, composited, and shaped before being cut to obtain a product with a basis weight of 1400 g / m². 2 The cotton fiber layer is wrapped with non-woven fabric and then pressed into strip-shaped fiber layers.

[0093] S2. Fix the cotton thread to the center of the strip fiber layer, with the end of the cotton thread exposed 15cm outside the strip fiber layer. Then, roll the strip fiber layer to form a long cylindrical absorbent body. After pressing it in the forming device with a pressure of 1MPa, microwave heating treatment is performed. The microwave heating temperature is 58℃ and the heating time is 5s to obtain the tampon body.

[0094] S3. Wrap the tampon body from the side with PE packaging film and glue both ends to obtain a tea bag-shaped finger-insertion tampon.

[0095] The method for preparing the pretreated cotton fibers includes the following steps:

[0096] (1) Disperse 300g of cotton fiber into 5L of sodium hydroxide aqueous solution with a concentration of 3wt%, add 21g of fatty alcohol polyoxyethylene ether as a wetting agent, heat and stir at 90℃ for 50min, cool to room temperature and take out the cotton fiber, wash repeatedly with deionized water until the pH of the washing solution is neutral, and dry at 80℃ to obtain refined cotton fiber.

[0097] (2) Take 100g of refined cotton fiber and 30g of 2,3-epoxypropyltrimethylammonium chloride and add them to 500mL of sodium hydroxide aqueous solution with a concentration of 8wt%. Stir and react at 60℃ for 2h. After the reaction is completed, take out the fiber, wash it thoroughly with deionized water until the pH of the washing solution is neutral, and dry it at 80℃ to obtain cationic cotton fiber.

[0098] (3) The cationic cotton fiber and the refined cotton fiber were dried at 80°C to a moisture content of ≤8%. 100g of cationic cotton fiber and 100g of refined cotton fiber were dry-opened to obtain 200g of mixed fiber. 50g of ethylene glycol diglycidyl ether and 12g of NaOH were dissolved in an appropriate amount of isopropanol / water (volume ratio 1:1) mixed solvent to prepare a crosslinking impregnation solution. The above 200g of mixed fiber was added to the crosslinking impregnation solution and reacted at 70°C for 3h. After the reaction was completed, the fiber was taken out, washed thoroughly with deionized water, dehydrated and dried at 80°C to obtain pretreated cotton fiber.

[0099] The difference between Comparative Example 4 and Example 1 is that the same mass of refined cotton fiber is used instead of anionized cotton fiber, and the cross-linked network contains only cationic groups, so there is no synergistic constraint effect of electrostatic attraction between fibers.

[0100] Performance testing

[0101] Compression resilience test:

[0102] Take the tampons prepared in each embodiment and comparative example, apply a 30N load (simulating the finger pressure during insertion) on a universal testing machine to compress the tampons to 50% of their original diameter, hold the pressure for 30 seconds, unload, let stand for 5 minutes, and then measure the diameter of the tampons. Calculate the compression rebound rate using the following formula:

[0103] Compression rebound rate (%) = (Diameter after unloading - Diameter after compression - Original diameter) / (Original diameter - Diameter after compression) × 100%

[0104] The lower the compression rebound rate, the better the shape retention of the swab body under compression.

[0105] Dimensional stability test:

[0106] After sealing and storing each group of tampons under standard packaging conditions for 24 hours, the diameter of the tampons was measured and compared with the initial diameter after being pressed and shaped by the molding machine. The dimensional change rate was calculated to evaluate the degree of expansion of the tampons during the packaging and storage process.

[0107] The test results are shown in Table 1:

[0108] Table 1 Performance test results of tea bag type finger-insertion tampons

[0109] Compression rebound rate (%) Dimensional change rate (%) Example 1 10.5 3.3 Example 2 12.2 4.2 Example 3 13.1 3.8 Comparative Example 1 30.5 12.3 Comparative Example 2 33.2 13.5 Comparative Example 3 40.6 16.8 Comparative Example 4 26.7 10.4

[0110] As can be seen from the experimental results in Table 1, the tea bag-shaped finger-insertion swabs prepared by this invention have good compression and shape retention properties, and their dimensions are stable after pressing and molding, which is conducive to the smooth insertion operation.

[0111] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A method for preparing a tea bag-shaped finger-insertion tampon, characterized in that, Includes the following steps: S1. The pretreated cotton fibers are combed and laid into a single layer of cotton fibers after combing. Then, the single layer of cotton fibers is stacked, composite and shaped, and cut to obtain a cotton fiber layer. The cotton fiber layer is wrapped with non-woven fabric and then pressed into a strip fiber layer. S2. Fix the cotton thread in the center of the strip fiber layer, with the end of the cotton thread exposed 10-20cm outside the strip fiber layer. Then, roll the strip fiber layer to form a long cylindrical absorbent body. After pressing and shaping in the forming device, microwave heating treatment is performed to obtain the tampon body. S3. Wrap the tampon body from the side with packaging film and glue the two ends to obtain a tea bag-shaped finger-insertion tampon.

2. The preparation method according to claim 1, characterized in that: In step S1, the weight of the single-layer cotton fiber is 12-16 g / m². 2 .

3. The preparation method according to claim 1, characterized in that: In step S1, the weight of the cotton fiber layer is 600-1600 g / m². 2 .

4. The preparation method according to claim 1, characterized in that, The method for preparing the pretreated cotton fibers includes the following steps: (1) Disperse cotton fibers in an aqueous sodium hydroxide solution, add a wetting agent, heat and stir, cool, remove the cotton fibers, wash with water until the filtrate is neutral, and then dry to obtain refined cotton fibers; (2) Take refined cotton fiber and react it with 2,3-epoxypropyltrimethylammonium chloride under alkaline conditions. Take out the fiber, wash it with water and then dry it to obtain cationic cotton fiber. (3) Take refined cotton fiber, sodium hydroxide aqueous solution and ethanol aqueous solution, mix and stir evenly, add monochloroacetic acid, heat and react, after the reaction is completed, cool, take out the fiber, wash with water and then dry to obtain anionized cotton fiber; (4) Equal masses of cationic cotton fibers and anionic cotton fibers are dry-opened to obtain mixed fibers. Then, ethylene glycol diglycidyl ether and sodium hydroxide are dissolved in a mixed solvent of isopropanol / water to prepare a crosslinking impregnation solution. The above mixed fibers are added to the crosslinking impregnation solution and heated to react. After the reaction is completed, the fibers are taken out, washed, dehydrated and dried to obtain pretreated cotton fibers.

5. The preparation method according to claim 4, characterized in that: In step (1), the concentration of the sodium hydroxide aqueous solution is 2-5 wt%, the heating and stirring temperature is 85-95℃, and the time is 45-60 min; the wetting agent is at least one of fatty alcohol polyoxyethylene ether, sodium dodecyl sulfate, Tween-20, Tween-80, and alkyl glycoside; the amount of the wetting agent is 0.3-0.6% of the mass of the sodium hydroxide aqueous solution.

6. The preparation method according to claim 4, characterized in that: In step (2), the mass ratio of refined cotton fiber to 2,3-epoxypropyltrimethylammonium chloride is 1:0.2-0.5; the stirring reaction temperature is 55-65℃ and the reaction time is 1.5-2.5h.

7. The preparation method according to claim 4, characterized in that: In step (3), the mass ratio of refined cotton fiber to monochloroacetic acid is 1:0.5-0.8; the heating reaction temperature is 60-70℃ and the reaction time is 1-1.5h.

8. The preparation method according to claim 4, characterized in that: In step (4), the moisture content of cationic cotton fiber and anionic cotton fiber is ≤8%.

9. The preparation method according to claim 4, characterized in that: In step (4), the total mass ratio of cationic cotton fiber and anionic cotton fiber to ethylene glycol diglycidyl ether and NaOH is 100:20-30:5-8; the heating reaction temperature is 60-80℃ and the reaction time is 2-4h.

10. A tea bag-shaped finger-insertion tampon, characterized in that: It is prepared by the preparation method according to any one of claims 1-9.