A disposable tampon and its preparation method

Abstract

The present invention discloses a flushable tampon and a preparation method thereof, comprising the following steps: S1, preparing a cotton fiber layer; S2, wrapping the cotton fiber layer with non-woven fabric, and obtaining a strip-shaped fiber layer after pressing. Place a drawstring at the central part of the strip-shaped fiber layer, and fix the drawstring and the strip-shaped fiber layer with a modified sewing thread to obtain a strip-shaped fiber layer with a drawstring; S3, preparing a tampon body of the tampon; S4, preparing a flushable tampon. The flushable tampon provided by the present invention, by using a modified sewing thread, when the tampon is immersed in cold water for a certain period of time, the modified sewing thread can be partially dissolved in water, and its mechanical properties are significantly reduced, and the tampon can be flushed away by the flushing force of the toilet, thus realizing that the tampon can be directly thrown into the toilet after use, and solving the problems of collection and treatment after the use of the tampon.

Description

Technical Field

[0001] The invention belongs to the technical field of tampon preparation, and particularly relates to a flushable tampon and a preparation method thereof. Background Art

[0002] Tampons, also known as sanitary plugs, can be inserted into the vagina to absorb menstrual blood. Tampons are a cotton cylinder, mainly made of cotton, synthetic fibers or a mixture of these two materials, with diameters ranging from 1 cm to 1.9 cm, with a cotton thread (drawstring) attached to the end. The degree of arc at the tip of the tampon varies from brand to brand, allowing users to choose according to their own usage habits.

[0003] The preparation method of conventional tampons is as follows: a certain amount of cotton fiber, viscose fiber, or a mixture of these two fibers is made into strips by combing or not limited to combing, and then sliced into sheets, and then multiple layers of sheet fibers are stacked, and then non-woven fabrics are coated, and then the drawstring is fixed to the center of the tampon using sewing thread, compressed, and then loaded into a catheter to form a tampon. Since the sewing thread used is an insoluble polymer fiber, if it is directly put into the toilet after use, due to the fixing effect of the sewing thread, the multiple layers of fibers cannot be scattered and cannot be washed away by water flow, which easily causes toilet blockage. Therefore, after the existing tampons are used, a special trash can must be placed in the toilet to collect the used tampons. After being placed for a long time, not only will there be odor in the trash can, but also a large number of bacteria will grow, and the subsequent incineration of the collected disposable sanitary products will produce harmful gases, which will pollute the ambient air.

[0004] Chinese patent CN115463245A discloses a flushable disposable sanitary product, which includes a surface layer, an absorption layer and a bottom film layer; the surface layer is made of a water-soluble non-woven fabric or paper material; the absorption layer is arranged below the surface layer and is composed of wood pulp or multiple layers of paper materials; the bottom film layer is arranged below the absorption layer and is made of a water-soluble non-woven fabric or paper material, and a water-repellent material layer is arranged on the side of the bottom film layer facing the absorption layer; wherein the surface layer, the absorption layer and the bottom film layer are compounded by at least one of ultrasonic lamination, hot pressing process or hydrosol bonding. All materials used in the flushable disposable sanitary product of the invention can be dissolved in water and flushed away. After use, consumers can directly throw the disposable sanitary products into the toilet and flush them away. It is convenient to use and there is no need to set up a special garbage can in the toilet to collect them, which solves the problem of collecting and disposing of disposable sanitary products after use. The application also discloses a method for making disposable sanitary products. However, the invention mainly prepares sanitary napkins, and achieves the flushable effect through water-soluble glue, while tampons do not involve adhesives, so it is not suitable for tampons.

[0005] In the prior art, there are few reports on flushable tampons. Therefore, it is of great significance to develop a tampon that can be flushed with water in this field. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a flushable tampon and its preparation method. By using modified sewing thread, when the tampon is immersed in cold water for a certain period of time, the modified sewing thread can be partially dissolved in water, and its mechanical properties are significantly reduced. The tampon can be flushed away by the flushing force of the toilet, thus realizing that the tampon can be directly thrown into the toilet after use, and solving the problems of collection and disposal after the use of the tampon.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A preparation method of a flushable tampon, comprising the following steps:

[0009] S1. Card the cotton fibers, lay them into a single layer of cotton fibers after carding, and then stack and compound the single layer of cotton fibers and cut them to obtain a cotton fiber layer;

[0010] S2. Wrap the cotton fiber layer in step S1 with non-woven fabric, press it to obtain a strip-shaped fiber layer, then place the drawstring in the center of the strip-shaped fiber layer, expose the end of the cotton thread 10-20 cm outside the strip-shaped fiber layer, and fix the drawstring and the strip-shaped fiber layer with modified sewing thread to obtain a strip-shaped fiber layer with a drawstring;

[0011] S3. Curl the strip-shaped fiber layer with a drawstring in step S2 to form a long cylindrical absorbent body, and press and mold it in a former to obtain the tampon body of the tampon;

[0012] S4. Load the tampon body in step S3 into a catheter to obtain the flushable tampon.

[0013] Preferably, the gram weight of the single layer of cotton fibers in step S1 is 12-16 g / m 2 , and the gram weight of the cotton fiber layer is 120-200 g / m 2 .

[0014] More preferably, the gram weight of the single layer of cotton fibers in step S1 is 13-15 g / m 2 , and the gram weight of the cotton fiber layer is 140-180 g / m 2 .

[0015] Preferably, the gram weight of the non-woven fabric in step S2 is 30-50 g / m 2 .

[0016] More preferably, the grammage of the non-woven fabric in step S2 is 35-45 g / m 2 .

[0017] Preferably, the preparation method of the modified sewing thread in step S2 includes the following steps:

[0018] (a) Add montmorillonite to deionized water, then add Tween-20, and carry out a stirring reaction. After the reaction is completed, filter, wash, and dry to obtain pretreated montmorillonite;

[0019] (b) Add the pretreated montmorillonite in step (a) to an ethanol aqueous solution, then add γ-mercaptopropyltrimethoxysilane, and carry out a heating reaction. After the reaction is completed, filter, wash, and dry to obtain mercapto-functionalized montmorillonite;

[0020] (c) Add the mercapto-functionalized montmorillonite obtained in step (b) to toluene, then add 10-undecenoic acid and azobisisobutyronitrile, and carry out a constant-temperature reaction. After the reaction is completed, filter, wash, and dry to obtain modified montmorillonite;

[0021] (d) Add polyvinyl alcohol to deionized water, stir and dissolve it, then add the modified montmorillonite in step (c), and then add ferric chloride to carry out a reaction. After the reaction is completed, a polyvinyl alcohol mixed solution is obtained; the polyvinyl alcohol mixed solution is degassed under reduced pressure at 95 °C, and then dry spinning is carried out to obtain the modified sewing thread.

[0022] Preferably, the mass ratio of the montmorillonite, deionized water, and Tween-20 in step (a) is 50-70:1000:1-3, the temperature of the stirring reaction is 70-80 °C, and the time is 1-2 h.

[0023] More preferably, the mass ratio of the montmorillonite, deionized water, and Tween-20 in step (a) is 55-65:1000:1-2, the temperature of the stirring reaction is 75-80 °C, and the time is 1-1.5 h.

[0024] In the present invention, the intercalation treatment of montmorillonite by Tween-20 increases the layer spacing of montmorillonite, enables better bonding force between montmorillonite and polyvinyl alcohol, and improves the mechanical properties of the modified sewing thread.

[0025] Preferably, the mass fraction of ethanol in the ethanol aqueous solution in step (b) is 70-80%, the mass ratio of the pretreated montmorillonite and γ-mercaptopropyltrimethoxysilane is 50-70:2-4, the temperature of the heating reaction is 60-70 °C, and the time is 2-4 h.

[0026] More preferably, the mass fraction of ethanol in the ethanol aqueous solution in step (b) is 70-80%, the mass ratio of the pretreated montmorillonite to γ-mercaptopropyltrimethoxysilane is 60-70:3-4, the temperature of the heating reaction is 65-70 °C, and the time is 2-3 h.

[0027] In the present invention, γ-mercaptopropyltrimethoxysilane is used to modify montmorillonite soil. On the one hand, the dispersibility of montmorillonite is improved, and on the other hand, the introduced mercapto group is also beneficial to the subsequent reaction.

[0028] Preferably, the mass ratio of the mercapto-functionalized montmorillonite, 10-undecenoic acid, and azobisisobutyronitrile in step (c) is 50-70:1.8-3.6:0.3-0.5; the temperature of the constant temperature reaction is 90-100 °C, and the time is 2-3 h.

[0029] More preferably, the mass ratio of the mercapto-functionalized montmorillonite, 10-undecenoic acid, and azobisisobutyronitrile in step (c) is 60-70:2.4-3.6:0.4-0.5; the temperature of the constant temperature reaction is 95-100 °C, and the time is 2-2.5 h.

[0030] In the present invention, 10-undecenoic acid is introduced onto the montmorillonite through a thiol-ene reaction of the mercapto-functionalized montmorillonite, which can not only improve the hydrophobicity of the montmorillonite, but also the carboxyl group contained in the introduced 10-undecenoic acid is beneficial to the subsequent reaction.

[0031] Preferably, the polyvinyl alcohol in step (d) is composed of medium alcoholysis degree polyvinyl alcohol and high alcoholysis degree polyvinyl alcohol with a mass ratio of 7-8:2-3. The medium alcoholysis degree polyvinyl alcohol is polyvinyl alcohol with an alcoholysis degree between 85% and 89%, and the high alcoholysis degree polyvinyl alcohol is polyvinyl alcohol with an alcoholysis degree between 89% and 95%; the mass ratio of the polyvinyl alcohol, deionized water, modified montmorillonite, and ferric chloride is 30-40:120-150:1.5-2.5:0.2-0.4, the temperature of the reaction is 70-80 °C, and the time is 1-2 h.

[0032] Specifically, the polyvinyl alcohol in step (d) is composed of medium alcoholysis degree polyvinyl alcohol and high alcoholysis degree polyvinyl alcohol with a mass ratio of 7-8:2-3. The medium alcoholysis degree polyvinyl alcohol is polyvinyl alcohol with an alcoholysis degree between 85% and 89% and a polymerization degree of 500-1700; the high alcoholysis degree polyvinyl alcohol is polyvinyl alcohol with an alcoholysis degree between 89% and 95% and a polymerization degree of 700-2400; the mass ratio of the polyvinyl alcohol, deionized water, modified montmorillonite, and ferric chloride is 35-40:130-140:1.5-2:0.3-0.4, the temperature of the reaction is 75-80 °C, and the time is 1-1.5 h.

[0033] In the present invention, a modified sewing thread is obtained by dry spinning a polyvinyl alcohol mixed solution. Before dry spinning, the viscosity of the polyvinyl alcohol mixed solution is adjusted to 200 - 300 Pa·s, and the temperature is 100 °C. The polyvinyl alcohol mixed solution is sent to a spinning machine through a gear pump, enters a spinning duct through a metering pump and a spinneret assembly, and the moisture in the filament is evaporated by hot air in the spinning duct. The temperature of the upper air inlet is 120 °C, the temperature of the lower air inlet is 120 °C, the spinning speed is 50 m / min, the filament is oiled, collected and wound to obtain a nascent fiber. The nascent fiber is then post-drawn and heat-set. The draw ratio is 5, and the heat-setting temperature is 120 °C, thus obtaining the modified sewing thread. The linear density of the modified sewing thread is 3 - 6 dtex.

[0034] In the present invention, through the esterification reaction of the carboxyl group on the modified montmorillonite and the hydroxyl group on the polyvinyl alcohol, the montmorillonite is introduced onto the polyvinyl alcohol in the form of a covalent bond, which not only improves the mechanical properties of the polyvinyl alcohol sewing thread but also delays the dissolution rate of the polyvinyl alcohol in water, making the prepared tampon have good comprehensive properties.

[0035] In the present invention, the applicant unexpectedly found that when the medium degree of alcoholysis polyvinyl alcohol and the high degree of alcoholysis polyvinyl alcohol are in the above ratio, the prepared modified sewing thread has good mechanical properties and is soluble at room temperature. When the added modified montmorillonite is in the above ratio range, the dissolution time of the modified sewing thread in water is moderate, which is 6 - 10 h. When the added amount is too small, the modified sewing thread dissolves too fast, which may cause the drawstring to fall off from the cotton core during the pulling process after the tampon is used; when the added amount is too large, it will cause the modified sewing thread to not dissolve for a long time, and the tampon is not easily flushed away.

[0036] Preferably, the pressure of the press molding in step S3 is 5 - 10 MPa, the temperature is 160 - 190 °C, and the time is 10 - 20 s.

[0037] The present invention also protects a dispersible tampon prepared by the method as described above.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The dissolvable tampon provided by the present invention is prepared with a modified sewing thread. Two kinds of polyvinyl alcohol are used as raw materials. The medium alcoholysis degree polyvinyl alcohol has good water solubility and can dissolve in water at room temperature, but its mechanical properties are poor and it cannot play a fixing role after absorbing water. The high alcoholysis degree polyvinyl alcohol generally only dissolves in hot water at 60 - 70°C, has strong mechanical properties, and can swell in cold water. By blending and spinning the two kinds of polyvinyl alcohol, not only the mechanical properties of the modified sewing thread are improved, but also its solubility at room temperature is ensured. And by adding modified montmorillonite, the layered structure of montmorillonite prolongs the path of water molecules, resulting in a decrease in the diffusion rate of water molecules in polyvinyl alcohol. At the same time, the 10-undecenoic acid introduced on the montmorillonite contains long-chain hydrophobic alkanes. The increase in the content of hydrophobic groups makes it difficult for water to contact more water molecules in the PVA sewing thread, and its dissolution process is greatly slowed down. Therefore, the final complete dissolution time will be greatly extended, so that the obtained sewing thread has a certain dissolution time, ensuring that when the tampon is in use, the internal sewing thread will not be separated from the cotton core due to dissolution, resulting in the cotton core being difficult to pull out. After the tampon is used up and put into the toilet, after the tampon is immersed in water for a certain time (6 - 10h), the sewing thread will dissolve and its mechanical properties will decrease significantly, and the tampon will be flushed and dispersed by the flushing force in the toilet, thus solving the problem of the tampon blocking the toilet.

[0040] (2) The dissolvable tampon provided by the present invention, by using the modified sewing thread, when the tampon is immersed in cold water for a certain time, the modified sewing thread can be partially dissolved in water, and its mechanical properties will decrease significantly, and the tampon can be flushed and dispersed by the flushing force in the toilet, thus realizing that the tampon can be directly thrown into the toilet after use, and solving the problems of collection and treatment after the tampon is used. Detailed implementation mode

[0041] The technical solutions of the present invention will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] The model of the medium alcoholysis degree polyvinyl alcohol is PVA-1788 (degree of polymerization is 1700, alcoholysis degree is 88%); the high alcoholysis degree polyvinyl alcohol is one of PVA-1795 (degree of polymerization is 1700, alcoholysis degree is 95%) and PVA-2495 (degree of polymerization is 2400, alcoholysis degree is 95%); the montmorillonite is nano-montmorillonite, purchased from Guangzhou Yifeng Chemical Technology Co., Ltd., and the particle size is 50 - 80nm.

[0043] Example 1

[0044] A preparation method of a flushable tampon, comprising the following steps:

[0045] S1. Card the cotton fibers, and after carding, lay them into a single layer of cotton fibers. The gram weight of the single layer of cotton fibers is 14 g / m 2 , and then stack and compound and shape the single layer of cotton fibers, and then obtain a cotton fiber layer through cutting. The gram weight of the cotton fiber layer is 180 g / m 2 ;

[0046] S2. Wrap the cotton fiber layer in step S1 with non-woven fabric. The gram weight of the non-woven fabric is 40 g / m 2 , and after pressing, obtain a strip-shaped fiber layer. Then place the drawstring at the central part of the strip-shaped fiber layer, with the tail end of the cotton thread exposed 15 cm outside the strip-shaped fiber layer, and fix the drawstring and the strip-shaped fiber layer with a modified sewing thread to obtain a strip-shaped fiber layer with a drawstring;

[0047] S3. Curl the strip-shaped fiber layer with a drawstring in step S2 to form a long cylindrical absorbent body. After pressing and shaping in a former, the pressure for pressing and shaping is 8 MPa, the temperature is 170 °C, and the time is 15 s to obtain the tampon body of the tampon;

[0048] S4. Load the tampon body in step S3 into a catheter to obtain the flushable tampon.

[0049] Among them, the preparation method of the modified sewing thread in step S2 comprises the following steps:

[0050] (a) Add 60 g of montmorillonite to 1000 g of deionized water, then add 2 g of Tween-20, and stir and react at 75 °C for 1.5 h. After the reaction is completed, filter, wash, and dry to obtain pretreated montmorillonite;

[0051] (b) Add 60 g of the pretreated montmorillonite in step (a) to 1 L of an ethanol aqueous solution (the mass fraction of ethanol is 75%), then add 3 g of γ-mercaptopropyltrimethoxysilane, and react at 65 °C for 3 h. After the reaction is completed, filter, wash, and dry to obtain mercapto-functionalized montmorillonite;

[0052] (c) Add 60 g of the mercapto-functionalized montmorillonite obtained in step (b) to 800 mL of toluene, then add 2.5 g of 10-undecenoic acid and 0.4 g of azobisisobutyronitrile, and react at a constant temperature of 95 °C for 2.5 h. After the reaction is completed, filter, wash, and dry to obtain modified montmorillonite;

[0053] (d) Add 270 g of PVA-1788 and 90 g of PVA-1795 in a mass ratio to 1400 g of deionized water. Stir and dissolve at 90 °C, then add 20 g of the modified montmorillonite in step (c). Next, add 3 g of ferric chloride and react at 75 °C for 1.5 h. After the reaction is completed, a polyvinyl alcohol mixture is obtained. Adjust the viscosity of the polyvinyl alcohol mixture to 250 Pa·s at 100 °C, perform vacuum degassing at 95 °C, and then send the polyvinyl alcohol mixture to a spinning machine through a gear pump. Enter the spinning duct through a metering pump and a spinneret assembly. Evaporate the water in the filaments through the hot air in the spinning duct. The temperature of the upper air inlet is 120 °C, the temperature of the lower air inlet is 120 °C, the spinning speed is 50 m / min. The filaments are oiled and collected and wound to obtain primary fibers. The primary fibers are then post-drawn and heat-set. The draw ratio is 5, and the heat-setting temperature is 120 °C, thus obtaining a modified sewing thread with a linear density of 4 dtex.

[0054] Example 2

[0055] A preparation method of a disposable tampon, comprising the following steps:

[0056] S1. Card the cotton fibers. After carding is completed, lay them into a single layer of cotton fibers. The gram weight of the single layer of cotton fibers is 12 g / m 2 , and then stack and compound and shape the single layer of cotton fibers, and then obtain a cotton fiber layer through cutting. The gram weight of the cotton fiber layer is 120 g / m 2 ;

[0057] S2. Wrap the cotton fiber layer in step S1 with non-woven fabric. The gram weight of the non-woven fabric is 30 g / m 2 , and obtain a strip-shaped fiber layer after pressing. Then place a drawstring in the center of the strip-shaped fiber layer, with the end of the cotton thread exposed 15 cm outside the strip-shaped fiber layer, and fix the drawstring and the strip-shaped fiber layer with a modified sewing thread to obtain a strip-shaped fiber layer with a drawstring;

[0058] S3. Curl the strip-shaped fiber layer with a drawstring in step S2 to form a long cylindrical absorber. After pressing and shaping in a former, the pressure for pressing and shaping is 5 MPa, the temperature is 160 °C, and the time is 20 s to obtain the tampon body of the tampon;

[0059] S4. Put the tampon body in step S3 into a catheter to obtain the disposable tampon.

[0060] Among them, the preparation method of the modified sewing thread in step S2 includes the following steps:

[0061] (a) Add 50 g of montmorillonite to 1000 g of deionized water, then add 1 g of Tween-20, stir and react at 70 °C for 2 h. After the reaction is completed, filter, wash, and dry to obtain pretreated montmorillonite;

[0062] (b) Add 50 g of the pretreated montmorillonite in step (a) to 1 L of an ethanol aqueous solution (the mass fraction of ethanol is 70%), then add 2 g of γ-mercaptopropyltrimethoxysilane, react at 60 °C for 4 h, filter, wash, and dry after the reaction is completed to obtain mercapto-functionalized montmorillonite;

[0063] (c) Add 50 g of the mercapto-functionalized montmorillonite obtained in step (b) to 800 mL of toluene, then add 1.8 g of 10-undecenoic acid and 0.3 g of azobisisobutyronitrile, react at a constant temperature of 90 °C for 3 h, filter, wash, and dry after the reaction is completed to obtain modified montmorillonite;

[0064] (d) Add 210 g of PVA-1788 and 90 g of PVA-2495 with a mass ratio to 1200 g of deionized water, stir and dissolve at 90 °C, then add 15 g of the modified montmorillonite in step (c), then add 2 g of ferric chloride, react at 70 °C for 2 h, and obtain a polyvinyl alcohol mixture after the reaction is completed; adjust the viscosity of the polyvinyl alcohol mixture to 200 Pa·s at 100 °C, carry out vacuum degassing at 95 °C, then send the polyvinyl alcohol mixture to a spinning machine through a gear pump, enter the spinning channel through a metering pump and a spinneret assembly, evaporate the moisture in the filament through the hot air in the spinning channel, the upper air inlet temperature is 120 °C, the lower air inlet temperature is 120 °C, the spinning speed is 50 m / min, the filament is oiled, collected and wound to obtain a nascent fiber, and the nascent fiber is further post-drawn and heat-set, the draw ratio is 5, and the heat-set temperature is 120 °C, thus obtaining a modified sewing thread with a linear density of 3 tex.

[0065] Example 3

[0066] A preparation method of a disposable tampon, comprising the following steps:

[0067] S1. Card the cotton fibers, and lay them into a single-layer cotton fiber after carding. The gram weight of the single-layer cotton fiber is 16 g / m 2 , and then stack and compound and shape the single-layer cotton fiber, and then obtain a cotton fiber layer through cutting. The gram weight of the cotton fiber layer is 200 g / m 2 ;

[0068] S2. Wrap the cotton fiber layer in step S1 with non-woven fabric. The gram weight of the non-woven fabric is 50 g / m 2 , obtain a strip-shaped fiber layer after pressing, then place a drawstring at the center of the strip-shaped fiber layer, the tail end of the cotton thread is exposed 15 cm outside the strip-shaped fiber layer, and fix the drawstring and the strip-shaped fiber layer with a modified sewing thread to obtain a strip-shaped fiber layer with a drawstring;

[0069] S3. Curl the strip-shaped fiber layer with a drawstring in step S2 to form a long cylindrical absorbent body. After pressing and forming in a former, the pressure for pressing and forming is 10 MPa, the temperature is 190 °C, and the time is 10 s to obtain the tampon body of the tampon.

[0070] S4. Load the tampon body in step S3 into a catheter to obtain the disposable tampon.

[0071] Among them, the preparation method of the modified sewing thread in step S2 includes the following steps:

[0072] (a) Add 70 g of montmorillonite to 1000 g of deionized water, then add 3 g of Tween-20, stir and react at 80 °C for 1 h. After the reaction is completed, filter, wash, and dry to obtain pretreated montmorillonite.

[0073] (b) Add 70 g of the pretreated montmorillonite in step (a) to 1 L of an ethanol aqueous solution (the mass fraction of ethanol is 80%), then add 4 g of γ-mercaptopropyltrimethoxysilane, and react at 70 °C for 2 h. After the reaction is completed, filter, wash, and dry to obtain mercapto-functionalized montmorillonite.

[0074] (c) Add 70 g of the mercapto-functionalized montmorillonite obtained in step (b) to 800 mL of toluene, then add 3.6 g of 10-undecenoic acid and 0.5 g of azobisisobutyronitrile, and react at a constant temperature of 100 °C for 2 h. After the reaction is completed, filter, wash, and dry to obtain modified montmorillonite.

[0075] (d) Add 320 g of PVA-1788 and 80 g of PVA-1795 to 1500 g of deionized water, stir and dissolve at 90 °C, then add 25 g of the modified montmorillonite in step (c), then add 4 g of ferric chloride, and react at 80 °C for 1 h to obtain a polyvinyl alcohol mixture. Adjust the viscosity of the polyvinyl alcohol mixture to 300 Pa·s at 100 °C, carry out vacuum degassing at 95 °C, then send the polyvinyl alcohol mixture to a spinning machine through a gear pump, enter the spinning channel through a metering pump and a spinneret assembly, evaporate the moisture in the filament through the hot air in the spinning channel, the temperature of the upper air inlet is 120 °C, the temperature of the lower air inlet is 120 °C, the spinning speed is 50 m / min, the filament is oiled, collected and wound to obtain a primary fiber, and the primary fiber is then post-drawn and heat-set, the draw ratio is 5, and the heat-setting temperature is 120 °C to obtain a modified sewing thread with a linear density of 6 tex.

[0076] Comparative Example 1

[0077] A preparation method of a disposable tampon includes the following steps:

[0078] S1. Comb the cotton fibers. After combing, lay them into a single layer of cotton fibers with a grammage of 14 g / m 2 , and then stack and compound the single layer of cotton fibers for shaping. After cutting, a cotton fiber layer is prepared. The grammage of the cotton fiber layer is 180 g / m 2 ;

[0079] S2. Wrap the cotton fiber layer obtained in step S1 with non-woven fabric with a grammage of 40 g / m 2 . After pressing, a strip-shaped fiber layer is obtained. Then, place a drawstring in the center of the strip-shaped fiber layer, with the tail end of the cotton thread exposed 15 cm outside the strip-shaped fiber layer. Fix the drawstring and the strip-shaped fiber layer with a modified sewing thread to obtain a strip-shaped fiber layer with a drawstring;

[0080] S3. Curl the strip-shaped fiber layer with a drawstring obtained in step S2 to form a long cylindrical absorbent body. After pressing and shaping in a former, the pressure for pressing and shaping is 8 MPa, the temperature is 170 °C, and the time is 15 s to obtain the tampon body of the sanitary tampon;

[0081] S4. Place the tampon body obtained in step S3 into a catheter to obtain the disposable sanitary tampon.

[0082] Among them, the preparation method of the modified sewing thread in step S2 includes the following steps:

[0083] (a) Add 60 g of montmorillonite to 1 L of an ethanol aqueous solution (the mass fraction of ethanol is 75%), then add 3 g of γ-mercaptopropyltrimethoxysilane, and react at 65 °C for 3 h. After the reaction is completed, filter, wash, and dry to obtain mercapto-functionalized montmorillonite;

[0084] (b) Add 60 g of the mercapto-functionalized montmorillonite obtained in step (a) to 800 mL of toluene, then add 2.5 g of 10-undecenoic acid and 0.4 g of azobisisobutyronitrile, and react at a constant temperature of 95 °C for 2.5 h. After the reaction is completed, filter, wash, and dry to obtain modified montmorillonite;

[0085] (c) Add 360 g of PVA-1795 to 1400 g of deionized water, stir and dissolve it at 90 °C, then add 20 g of modified montmorillonite in step (b), stir evenly to obtain a polyvinyl alcohol mixed solution; adjust the viscosity of the polyvinyl alcohol mixed solution to 250 Pa·s at 100 °C, carry out vacuum degassing at 95 °C, then send the polyvinyl alcohol mixed solution to a spinning machine through a gear pump, enter the spinning channel through a metering pump and a spinneret assembly, evaporate the moisture in the filaments through the hot air in the spinning channel, the upper air inlet temperature is 120 °C, the lower air inlet temperature is 120 °C, the spinning speed is 50 m / min, the filaments are oiled, collected and wound to obtain nascent fibers, and the nascent fibers are further post-drawn and heat-set, the draw ratio is 5, and the heat-setting temperature is 120 °C, thus obtaining a modified sewing thread with a linear density of 4 dtex.

[0086] Comparative Example 2

[0087] A preparation method of a disposable tampon, comprising the following steps:

[0088] S1. Card the cotton fibers, and after carding, lay them into a single layer of cotton fibers, and the gram weight of the single layer of cotton fibers is 14 g / m 2 , then stack and compound and shape the single layer of cotton fibers, and then cut to prepare a cotton fiber layer, and the gram weight of the cotton fiber layer is 180 g / m 2 ;

[0089] S2. Wrap the cotton fiber layer in step S1 with non-woven fabric, and the gram weight of the non-woven fabric is 40 g / m 2 , after pressing, obtain a strip-shaped fiber layer, then place a drawstring in the center of the strip-shaped fiber layer, the tail end of the cotton thread is exposed 15 cm outside the strip-shaped fiber layer, and use a modified sewing thread to fix the drawstring and the strip-shaped fiber layer to obtain a strip-shaped fiber layer with a drawstring;

[0090] S3. Curl the strip-shaped fiber layer with a drawstring in step S2 to form a long cylindrical absorbent body, and after pressing and shaping in a former, the pressure for pressing and shaping is 8 MPa, the temperature is 170 °C, and the time is 15 s to obtain the tampon body of the tampon;

[0091] S4. Put the tampon body in step S3 into a catheter to obtain the disposable tampon.

[0092] Among them, the preparation method of the modified sewing thread in step S2 includes the following steps:

[0093] (a) Add 60 g of montmorillonite to 1000 g of deionized water, then add 2 g of Tween-20, stir and react at 75 °C for 1.5 h, after the reaction is completed, filter, wash and dry to obtain pretreated montmorillonite;

[0094] (b) Add 270 g of PVA-1788 and 90 g of PVA-1795 with a mass ratio into 1400 g of deionized water, stir and dissolve at 90 °C, then add 20 g of the pretreated montmorillonite in step (a), then add 3 g of ferric chloride, react at 75 °C for 1.5 h, and obtain a polyvinyl alcohol mixed solution after the reaction is completed; adjust the viscosity of the polyvinyl alcohol mixed solution to 250 Pa·s at 100 °C, carry out vacuum degassing at 95 °C, then send the polyvinyl alcohol mixed solution to a spinning machine through a gear pump, enter the spinning channel through a metering pump and a spinneret assembly, evaporate the moisture in the filament through the hot air in the spinning channel, the temperature of the upper air inlet is 120 °C, the temperature of the lower air inlet is 120 °C, the spinning speed is 50 m / min, the filament is oiled, collected and wound to obtain a nascent fiber, and the nascent fiber is further post-drawn and heat-set, the draw ratio is 5, and the heat-set temperature is 120 °C, thus obtaining a modified sewing thread with a linear density of 4 dtex.

[0095] Perform mechanical property tests on the modified sewing threads prepared in Examples 1-3 and Comparative Examples 1-2, and the test results are shown in Table 1 below:

[0096] Table 1

[0097] Breaking strength cN / dtex Elongation at break / % Example 1 6.72 12.5 Example 2 6.49 10.8 Example 3 6.83 11.2 Comparative Example 1 8.15 13.6 Comparative Example 2 5.37 8.9

[0098] It can be seen from Table 1 that the modified sewing thread prepared by the present invention has good breaking strength and can be used to fix the drawstring and the cotton core. In Comparative Example 2, since the montmorillonite was not modified, the binding force between the montmorillonite and the polyvinyl alcohol decreased, resulting in a significant decrease in the mechanical properties of the modified sewing thread.

[0099] Perform dissolution experiments on the tampons prepared in Examples 1-3 and Comparative Examples 1-2, as follows: Put each group of tampons into 1 L of tap water (temperature 25 °C), stir at a constant speed after impregnation for 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, and observe whether the tampons are dispersed. The test results are shown in Table 2

[0100] Table 2

[0101] 2h 4h 6h 8h 10h 12h 14h Example 1 Not dispersed Not dispersed Not dispersed Dispersed / / / / Example 2 Not dispersed Not dispersed Dispersed / / / / Example 3 Not dispersed Not dispersed Not dispersed Not dispersed Dispersed / / Comparative Example 1 Not dispersed Not dispersed Not dispersed Not dispersed Not dispersed Not dispersed Not dispersed Comparative Example 2 Dispersed / / / / / /

[0102] It can be seen from Table 2 that the tampons prepared by the present invention can be dispersed within 6-10 h when impregnated in normal temperature water. In Comparative Example 1, since the polyvinyl alcohol used was PVA-1795 and the montmorillonite was modified, the dissolution rate of the modified sewing thread was prolonged too much, and the tampon could not be dispersed after being impregnated in water for 14 h; while in Comparative Example 2, since the montmorillonite was not modified, the dissolution rate of the modified sewing thread was too fast, and the tampon was dispersed after being impregnated in water for 2 h, which might cause the drawstring and the cotton core to fall off during the pulling process after the tampon was used, which was not conducive to the use of the tampon.

[0103] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a disposable tampon, characterized in that, It includes the following steps: S1. Card the cotton fibers. After carding, lay them into a single layer of cotton fibers. Then stack and compound and shape the single-layer cotton fibers, and cut them after shaping to obtain a cotton fiber layer; S2. Wrap the cotton fiber layer in step S1 with non-woven fabric, press it to obtain a strip-shaped fiber layer. Then place the drawstring at the center of the strip-shaped fiber layer, with the tail end of the cotton thread exposed 10-20 cm outside the strip-shaped fiber layer, and fix the drawstring and the strip-shaped fiber layer with a modified sewing thread to obtain a strip-shaped fiber layer with a drawstring; S3. Curl the strip-shaped fiber layer with a drawstring in step S2 to form a long strip-shaped cylindrical absorbent body, and press and shape it in a former to obtain the tampon body of the tampon; S4. Load the tampon body in step S3 into a catheter to obtain the disposable tampon; Among them, the preparation method of the modified sewing thread in step S2 includes the following steps: (a) Add montmorillonite to deionized water, then add Tween-20, stir and react. After the reaction is completed, filter, wash, and dry to obtain pretreated montmorillonite; (b) Add the pretreated montmorillonite in step (a) to an ethanol aqueous solution, then add γ-mercaptopropyltrimethoxysilane, and heat and react. After the reaction is completed, filter, wash, and dry to obtain mercapto-functionalized montmorillonite; (c) Add the mercapto-functionalized montmorillonite obtained in step (b) to toluene, then add 10-undecenoic acid and azobisisobutyronitrile, and carry out a constant-temperature reaction. After the reaction is completed, filter, wash, and dry to obtain modified montmorillonite; (d) Add polyvinyl alcohol to deionized water, stir and dissolve it, then add the modified montmorillonite in step (c), then add ferric chloride, and react. After the reaction is completed, obtain a polyvinyl alcohol mixture; Deaerate the polyvinyl alcohol mixture under reduced pressure at 95 °C, and then carry out dry spinning to obtain a modified sewing thread.

2. The preparation method according to claim 1, characterized in that, The grammage of the single-layer cotton fiber described in step S1 is 12-16 g / m 2 , and the grammage of the cotton fiber layer is 120-200 g / m 2 .

3. The preparation method according to claim 1, characterized in that, The grammage of the non-woven fabric described in step S2 is 30-50 g / m 2 .

4. The preparation method according to claim 1, wherein In step (a), the mass ratio of the montmorillonite, deionized water, and Tween-20 is 50-70:1000:1-3, the temperature of the stirring reaction is 70-80 °C, and the time is 1-2 h.

5. The preparation method according to claim 1, characterized in that, In step (b), the mass fraction of ethanol in the ethanol aqueous solution is 70-80%, the mass ratio of the pretreated montmorillonite and γ-mercaptopropyltrimethoxysilane is 50-70:2-4, the temperature of the heating reaction is 60-70 °C, and the time is 2-4 h.

6. The preparation method according to claim 1, characterized in that In step (c), the mass ratio of the mercapto-functionalized montmorillonite, 10-undecenoic acid, and azobisisobutyronitrile is 50-70:1.8-3.6:0.3-0.5; the temperature of the constant-temperature reaction is 90-100 °C, and the time is 2-3 h.

7. The preparation method according to claim 1, characterized in that, In step (d), the polyvinyl alcohol is composed of medium-degree alcoholysis polyvinyl alcohol and high-degree alcoholysis polyvinyl alcohol with a mass ratio of 7-8:2-3. The medium-degree alcoholysis polyvinyl alcohol is polyvinyl alcohol with an alcoholysis degree between 85% and 89%, and the high-degree alcoholysis polyvinyl alcohol is polyvinyl alcohol with an alcoholysis degree between 89% and 95%; the mass ratio of the polyvinyl alcohol, deionized water, modified montmorillonite, and ferric chloride is 30-40:120-150:1.5-2.5:0.2-0.4, the temperature of the reaction is 70-80 °C, and the time is 1-2 h.

8. The preparation method according to claim 1, characterized in that, The pressure for the compression molding described in step S3 is 5 - 10 MPa, the temperature is 160 - 190 °C, and the time is 10 - 20 s.

9. A disposable tampon prepared by the method according to any one of claims 1 - 8.