A preparation method of a soft polypropylene non-woven fabric

Abstract

This application relates to the field of textiles, and specifically discloses a method for preparing a soft polypropylene non-woven fabric, which includes the following steps: Weigh 45-50 parts of polypropylene, 45-50 parts of elastomer, 1-3 parts of soft masterbatch, and 0.5-1 part of dull white, mix them, and then through melt extrusion, spinning, and stretching, the first fiber filaments are obtained; Weigh 75-80 parts of polypropylene, 18-22 parts of elastomer, 1-3 parts of soft masterbatch, and 0.5-1 part of dull white, mix them, and then through melt extrusion, spinning, and stretching, the second fiber filaments are obtained; Weigh 75-80 parts of polypropylene, 18-22 parts of elastomer, 1-3 parts of soft masterbatch, and 0.5-1 part of dull white, mix them, and then through melt extrusion, spinning, and stretching, the third fiber filaments are obtained; Lay the three layers of fiber filaments on the net in sequence, and through hot rolling, post-treatment, curling, slitting, and packaging, the finished product is obtained; The finished product has softness, fluffiness, good air permeability, and certain hydrophilicity at the same time.

Description

Technical Field

[0001] This application relates to the field of textiles, and more specifically, it relates to a method for preparing a soft polypropylene non-woven fabric. Background Art

[0002] Polypropylene non-woven fabric is a non-woven fabric formed by forming fibers through air flow or mechanical means, then finishing by hydroentangling, needle punching or hot rolling, and finally finishing by post-treatment; polypropylene non-woven fabric has the advantages of light weight, softness and good air permeability, so it is widely used in the surface layer and bottom film of disposable sanitary products such as baby diapers, adult incontinence pants, sanitary napkins, elastic waistbands, etc., which can effectively improve the comfort of users.

[0003] In the prior art, a Chinese patent application document with the publication number CN115538039A discloses a method for preparing a soft non-woven fabric; the method for preparing the soft non-woven fabric includes the following steps: (1) Spinning and cooling: Mix polypropylene, short-chain silicon compound, polypropylene-polymer, plastomer, and titanium dioxide, then melt and heat, filter and distribute, and then spin and cool, and stretch by air flow to obtain modified polypropylene fiber filaments; (2) Drafting and web laying: Lay the modified polypropylene fiber filaments to obtain a three-layer fiber web; (3) Hot rolling and strengthening: Composite the three-layer fiber web through a hot rolling machine to obtain a soft non-woven fabric.

[0004] The existing polypropylene non-woven fabric has poor hydrophilicity. When making the surface layer of diapers, the non-woven fabric needs to have a certain hydrophilicity to facilitate the absorption of urine by the diapers; therefore, there is an urgent need to prepare a new polypropylene non-woven fabric that is soft, fluffy, has good air permeability and has a certain hydrophilicity. Summary of the Invention

[0005] In order to prepare a new polypropylene non-woven fabric that is soft, fluffy, has good air permeability and has a certain hydrophilicity, this application provides a method for preparing a soft polypropylene non-woven fabric.

[0006] This application provides a method for preparing a soft polypropylene non-woven fabric, adopting the following technical scheme:

[0007] A method for preparing a soft polypropylene non-woven fabric includes the following steps:

[0008] S1. Weigh 45-50 parts of polypropylene, 45-50 parts of elastomer, 1-3 parts of soft masterbatch, and 0.5-1 part of matte white by weight, mix them, and then melt extrude, spin and stretch to obtain the first fiber filaments;

[0009] S2. Weigh 75-80 parts of polypropylene, 18-22 parts of elastomer, 1-3 parts of soft masterbatch, and 0.5-1 part of matte white by weight, mix them, and then melt extrude, spin and stretch to obtain the second fiber filaments;

[0010] S3. Weigh 75 - 80 parts by weight of polypropylene, 18 - 22 parts of elastomer, 1 - 3 parts of soft masterbatch, and 0.5 - 1 part of matte white, mix them, and then obtain the third fiber filament through melt extrusion, spinning, and stretching.

[0011] S4. Lay the first fiber filament, the second fiber filament, and the third fiber filament in sequence on a net, and obtain the finished product through hot rolling, post - treatment, crimping, slitting, and packaging.

[0012] By adopting the above technical solution, the combination of polypropylene, elastomer, and soft masterbatch endows the polypropylene non - woven fabric with good elasticity and flexibility. With the design of laying three layers of fibers on the net, the finished non - woven fabric has a good fluffing effect; combined with the filling effect of the soft masterbatch and matte white, the strength of the polypropylene non - woven fabric is improved; at the same time, with the three - layer fiber net laid, there are pores between adjacent fiber filaments of the polypropylene non - woven fabric, ensuring the air permeability of the polypropylene non - woven fabric and improving its fluffiness.

[0013] Preferably, a sodium alginate composite solution is evenly sprayed between the first fiber net, the second fiber net, and the third fiber net, and then hot - rolled and compounded, ethanol - washed, post - treated, crimped, slit, and packaged to obtain the finished product.

[0014] By adopting the above technical solution, the combination of the three - layer fiber net and the filling and blocking effect of the sodium alginate composite solution improves the hydrophilicity of the polypropylene non - woven fabric. After ethanol - washing, the porosity of the polypropylene non - woven fabric is further increased, that is, while improving the air permeability, the water - permeable effect is improved, facilitating the circulation of moisture; making the finished polypropylene non - woven fabric have softness, fluffiness, good air permeability, and certain hydrophilicity at the same time.

[0015] Preferably, the sodium alginate composite solution is composed of sodium alginate, ethyl cellulose microspheres, multi - pore expanded perlite, and water with a mass ratio of 1:0.2 - 0.4:1 - 2:100 - 120.

[0016] By adopting the above technical solution, the combination of sodium alginate, ethyl cellulose microspheres, and multi - pore expanded perlite makes use of the viscosity generated by sodium alginate dissolving in water to facilitate the dispersion of ethyl cellulose microspheres and multi - pore expanded perlite in the sodium alginate solution. Using the filling effect of ethyl cellulose microspheres and multi - pore expanded perlite, the porosity after hot - rolling of the sodium alginate composite solution is further increased; after ethanol - washing, ethyl cellulose microspheres dissolve in ethanol and are easily removed, resulting in the loss of ethyl cellulose microspheres in the sodium alginate network, thereby further increasing the porosity of the sodium alginate network, increasing the porosity between adjacent fiber nets, and further increasing the porosity of the polypropylene non - woven fabric, thus improving the air permeability of the polypropylene non - woven fabric.

[0017] When spraying the sodium alginate composite solution between adjacent fiber meshes, the sodium alginate composite solution can only adhere to the surface of the fiber filaments, and the pores between the fiber filaments cannot load the sodium alginate composite solution without a support; the network structure formed by the sodium alginate composite solution facilitates hydrophilicity and attracts water circulation. Under the action of POE, matte white, and lubricant, the fiber filaments are hydrophobic, so that the sodium alginate network at the intersections of the fiber filaments is hydrophilic and allows water to flow through, while the pores between the fiber filaments maintain air permeability. When the polypropylene non-woven fabric is used to prepare a diaper, after absorbing urine, it is not easy for the pores to be blocked by water, which affects the air permeability of the polypropylene non-woven fabric.

[0018] Preferably, the particle size of the ethyl cellulose microspheres is 20 - 60 μm.

[0019] By adopting the above technical solution, limiting the particle size of the ethyl cellulose microspheres not only facilitates the washing and removal of the ethyl cellulose microspheres, but also avoids blocking the pores formed by the three-layer fiber mesh as much as possible, thus ensuring that the polypropylene non-woven fabric has good air permeability and fluffiness; and the ethyl cellulose microspheres play a supporting role in the network structure by using their filling effect in the sodium alginate composite solution, improving the porosity of the network structure of the sodium alginate composite solution. After the ethyl cellulose microspheres are dissolved, the porosity of the network structure formed by the sodium alginate composite solution is further increased, thereby improving the air permeability and hydrophilicity of the polypropylene non-woven fabric.

[0020] Preferably, the multi-porous expanded perlite is prepared by bonding silica after modifying multi-porous perlite with silane coupling agent KH-570.

[0021] By adopting the above technical solution, the multi-porous perlite, silane coupling agent KH-570, and silica are combined. Using the adsorption effect of the multi-porous perlite, it is convenient to adsorb the silane coupling agent KH-570. Using the hydrophobicity of the silane coupling agent KH-570, the internal pores of the multi-porous perlite are hydrophobic. When the polypropylene non-woven fabric is used as the surface layer of the diaper, when urine flows through the polypropylene non-woven fabric, the internal pores of the multi-porous perlite are not easy to allow urine to flow through, so it is not easy for the internal pores of the multi-porous perlite to be blocked by urine, ensuring the air permeability of the polypropylene non-woven fabric after moisture absorption; and silica is hydrophilic. The silica loaded on the surface of the multi-porous expanded perlite, using its hydrophilicity, facilitates the flow of water through the edges of the multi-porous expanded perlite, and the pores of the multi-porous expanded perlite are not easy to be blocked, ensuring hydrophilicity and water permeability while ensuring air permeability.

[0022] Preferably, the non-woven fabric further includes 1 - 3 parts of modified nano-cellulose, and the modified nano-cellulose is composed of nano-cellulose whiskers, maleic anhydride grafted POE, and nano-silver powder with a mass ratio of 1:0.1 - 0.3:0.02 - 0.1.

[0023] By adopting the above technical solution, nanocellulose whiskers, maleic anhydride grafted POE, and nanosilver powder are combined, and the bonding compatibility of maleic anhydride grafted POE and polypropylene is utilized to improve the bonding compatibility of nanocellulose whiskers and fiber filaments. The better flexibility and elasticity of nanocellulose whiskers are utilized in combination with POE to improve the flexibility and fluffiness of polypropylene non-woven fabrics. The addition of nanosilver powder not only has a filling effect and improves the strength of polypropylene non-woven fabrics, but also has an antibacterial effect. After being made into the surface layer of diapers, it absorbs and diverts urine, and its antibacterial effect is utilized to protect the health of babies.

[0024] Preferably, the post-processing steps are as follows: uniformly spraying chitosan solution and sepiolite on one side of the semi-finished product in sequence, and then uniformly spraying sodium lauroyl sarcosinate solution, and drying.

[0025] By adopting the above technical solution, chitosan solution, sepiolite and sodium lauroyl sarcosinate solution are combined, and the hydrophilicity of chitosan solution and sepiolite is utilized to improve the hydrophilicity of polypropylene non-woven fabric. In addition, the chitosan solution has porous air permeability after drying, which can ensure the breathable effect.

[0026] After the surface layer of the diaper is made, the hydrophilicity of the sodium alginate network and sepiolite is used to facilitate urine to flow through the sodium alginate network, chitosan network, sepiolite, and the polymer water-absorbent resin in the diaper in sequence. Since the polymer water-absorbent resin has a strong water absorption rate, the water only flows through the sodium alginate network, chitosan network and sepiolite, and will finally be absorbed by the polymer water-absorbent resin, making the polypropylene non-woven fabric made of diapers easy to absorb urine.

[0027] Sodium lauroyl sarcosinate has one hydrophilic end and the other hydrophobic end. The carboxyl group at the hydrophilic end is connected with the amino and carboxyl groups in the chitosan solution and the hydroxyl groups in the sepiolite, so that the hydrophilic group of sodium lauroyl sarcosinate faces the sepiolite side and the hydrophobic end faces outward, that is, the hydrophobic end faces the polymer absorbent resin, thereby minimizing the backflow of urine absorbed by the diaper.

[0028] Preferably, the chitosan solution is prepared by the following method:

[0029] Chitosan is weighed and placed in dilute acetic acid, dissolved and stirred to prepare a chitosan solution with a mass fraction of 1-5%, then glutaraldehyde is added, and the mass ratio of glutaraldehyde to chitosan solution is 100:1-3, and finally nano silver powder is added, and the mass ratio of nano silver powder to chitosan solution is 100:0.1-1, and mixed evenly to prepare a finished product.

[0030] By adopting the above technical solution, chitosan solution, nano silver powder, and modified nano cellulose are combined. By utilizing the antibacterial effect of chitosan solution in combination with the antibacterial and bactericidal effects of nano silver powder, as well as the antibacterial effect of nano silver powder in modified nano cellulose, the antibacterial effect of polypropylene non-woven fabric is improved. After making it into the surface layer of the diaper, the surface layer has high antibacterial and antimicrobial effects to protect the health of infants.

[0031] Preferably, the particle size of the sepiolite is 20 - 40 μm, and the open porosity is not less than 40%.

[0032] By adopting the above technical solution, the particle size and porosity of sepiolite are defined, ensuring the hydrophilic and water-absorbing properties of sepiolite while ensuring the air permeability of polypropylene non-woven fabric.

[0033] Preferably, the melting temperature in S1 is 220 - 230 °C.

[0034] By adopting the above technical solution, the forming effect of polypropylene non-woven fabric is relatively high, and the combination of the three-layer fiber webs is relatively stable.

[0035] In summary, the present application has the following beneficial effects:

[0036] 1. The combination of polypropylene, elastomer, and soft masterbatch endows the polypropylene non-woven fabric with good elasticity and flexibility. Combined with the laying design of three layers of fibers, the finished non-woven fabric has a good fluffy effect; further combined with the filling effects of soft masterbatch and matte white, the strength of polypropylene non-woven fabric is improved; at the same time, combined with the three-layer fiber webs laid, there are pores between adjacent fiber filaments of polypropylene non-woven fabric, ensuring the air permeability of polypropylene non-woven fabric and improving its fluffiness.

[0037] 2. When the non-woven fabric is hydrophilic and immersed in water, the pore structure is blocked by water, which easily affects the air permeability. However, the polypropylene non-woven fabric prepared in the present application can still ensure the air permeability of polypropylene non-woven fabric under the condition of ensuring the water circulation, enabling the surface layer of the prepared diaper to quickly absorb urine while ensuring the air permeability of the diaper.

[0038] 3. The combination of multi-porous perlite, silane coupling agent KH-570, and silica uses the hydrophobicity of silane coupling agent KH-570 to make the internal pores of multi-porous perlite hydrophobic. The silica loaded on the surface of multi-porous expanded perlite, due to its hydrophilicity, facilitates the water to flow through the edges of multi-porous expanded perlite, and the pores of multi-porous expanded perlite are not easily blocked, ensuring hydrophilicity, water permeability, and air permeability at the same time. Detailed implementation manners

[0039] The following further elaborates on the present application with reference to examples.

[0040] Preparation Examples of Sodium Alginate Composite Solution

[0041] Preparation Example 1: The sodium alginate composite solution was prepared by the following method:

[0042] Weigh 1 kg of multi-porous perlite and soak it in 10 kg of silane coupling agent KH-570 for dispersion. The particle size of the multi-porous perlite is 60 μm, and the open pore porosity is 50%. Stir at a speed of 1000 r / min for 10 min, then filter out the multi-porous perlite, and evenly spray 0.1 kg of silica on its surface. The particle size of the silica is 100 nm, and the spraying speed is 30 g / min. After drying, multi-porous expanded perlite is obtained;

[0043] Weigh 1 kg of sodium alginate and 110 kg of water, mix and stir until the sodium alginate is completely dissolved to obtain a sodium alginate solution; weigh 0.3 kg of ethyl cellulose microspheres and 1.5 kg of multi-porous expanded perlite, add them to the sodium alginate solution for dispersion and stirring. The particle size of the ethyl cellulose microspheres is 40 μm, and the addition speed is 60 g / min. During the addition process, the sodium alginate solution is stirred at a speed of 200 r / min. After mixing evenly, a sodium alginate composite solution is obtained.

[0044] Preparation Example 2: The difference between this preparation example and Preparation Example 1 is as follows:

[0045] Weigh 1 kg of sodium alginate and 100 kg of water, mix and stir until the sodium alginate is completely dissolved to obtain a sodium alginate solution; weigh 0.2 kg of ethyl cellulose microspheres and 1 kg of multi-porous expanded perlite, add them to the sodium alginate solution for dispersion and stirring. The particle size of the ethyl cellulose microspheres is 20 μm, and the addition speed is 60 g / min. During the addition process, the sodium alginate solution is stirred at a speed of 200 r / min. After mixing evenly, a sodium alginate composite solution is obtained.

[0046] Preparation Example 3: The difference between this preparation example and Preparation Example 1 is as follows:

[0047] Weigh 1 kg of sodium alginate and 120 kg of water, mix and stir until the sodium alginate is completely dissolved to obtain a sodium alginate solution; weigh 0.4 kg of ethyl cellulose microspheres and 2 kg of multi-porous expanded perlite, add them to the sodium alginate solution for dispersion and stirring. The particle size of the ethyl cellulose microspheres is 40 μm, and the addition speed is 60 g / min. During the addition process, the sodium alginate solution is stirred at a speed of 200 r / min. After mixing evenly, a sodium alginate composite solution is obtained.

[0048] Preparation Examples of Modified Nanocellulose

[0049] Among the following raw materials, maleic anhydride grafted POE was purchased from Guangdong Chuanheng New Materials Technology Co., Ltd.; nano-cellulose whiskers among the following raw materials were purchased from Beijing Nasson Technology Co., Ltd.; other raw materials and equipment are all commercially available.

[0050] Preparation Example 4: The modified nano-cellulose was prepared by the following method:

[0051] Weigh 0.2 kg of maleic anhydride grafted POE and heat it until it is completely melted to obtain a maleic anhydride grafted POE melt;

[0052] Spray the maleic anhydride grafted POE melt evenly on the surface of 1 kg of nano-cellulose whiskers. The length of the nano-cellulose whiskers is 300 nm and the diameter is 10 nm. Then spray 0.06 kg of nano-silver powder evenly. The particle size of the nano-silver powder is 60 nm. After drying and dispersing, the finished product is obtained, and the particle size of the finished product is less than 500 nm.

[0053] Preparation Example 5: The modified nano-cellulose was prepared by the following method:

[0054] Weigh 0.1 kg of maleic anhydride grafted POE and heat it until it is completely melted to obtain a maleic anhydride grafted POE melt;

[0055] Spray the maleic anhydride grafted POE melt evenly on the surface of 1 kg of nano-cellulose whiskers. The length of the nano-cellulose whiskers is 300 nm and the diameter is 10 nm. Then spray 0.02 kg of nano-silver powder evenly. The particle size of the nano-silver powder is 60 nm. After drying and dispersing, the finished product is obtained, and the particle size of the finished product is less than 500 nm.

[0056] Preparation Example 6: The modified nano-cellulose was prepared by the following method:

[0057] Weigh 0.3 kg of maleic anhydride grafted POE and heat it to 100 °C until it is completely melted to obtain a maleic anhydride grafted POE melt;

[0058] Spray the maleic anhydride grafted POE melt evenly on the surface of 1 kg of nano-cellulose whiskers. The length of the nano-cellulose whiskers is 300 nm and the diameter is 10 nm. Then spray 0.1 kg of nano-silver powder evenly. The particle size of the nano-silver powder is 60 nm. After drying and dispersing, the finished product is obtained, and the particle size of the finished product is less than 500 nm.

[0059] Preparation Example of Extinction White

[0060] Among the following raw materials, the extinction white is titanium dioxide.

[0061] Preparation Example 7: The extinction white was prepared by the following method:

[0062] Weigh 0.2 kg of maleic anhydride grafted POE and heat it to 100 °C until it is completely melted to obtain a maleic anhydride grafted POE melt;

[0063] Spray the maleic anhydride grafted POE solution evenly on the surface of 1 kg of matte white particles. The particle size of the matte white particles is 200 nm, the spraying speed of the maleic anhydride grafted POE solution is 30 g / min, the stirring speed of the matte white particles during spraying is 80 r / min. After mixing evenly, dry and disperse to obtain the finished matte white, and the particle size of the finished matte white is less than 500 nm.

[0064] Preparation Example 8: The matte white is prepared by the following method:

[0065] Weigh 0.1 kg of maleic anhydride grafted POE and heat it to 100 °C until it is completely melted to obtain the maleic anhydride grafted POE solution;

[0066] Spray the maleic anhydride grafted POE solution evenly on the surface of 1 kg of matte white particles. The particle size of the matte white particles is 200 nm, the spraying speed of the maleic anhydride grafted POE solution is 30 g / min, the stirring speed of the matte white particles during spraying is 80 r / min. After mixing evenly, dry and disperse to obtain the finished matte white, and the particle size of the finished matte white is less than 500 nm.

[0067] Preparation Example 9: The matte white is prepared by the following method:

[0068] Weigh 0.25 kg of maleic anhydride grafted POE and heat it to 100 °C until it is completely melted to obtain the maleic anhydride grafted POE solution;

[0069] Spray the maleic anhydride grafted POE solution evenly on the surface of 1 kg of matte white particles. The particle size of the matte white particles is 200 nm, the spraying speed of the maleic anhydride grafted POE solution is 30 g / min, the stirring speed of the matte white particles during spraying is 80 r / min. After mixing evenly, dry and disperse to obtain the finished matte white, and the particle size of the finished matte white is less than 500 nm.

[0070] Preparation Example of Chitosan Solution

[0071] Preparation Example 10: The chitosan solution is prepared by the following method:

[0072] Weigh chitosan and dissolve and stir it in dilute acetic acid to obtain a 3% chitosan solution by mass fraction. The dilute acetic acid is a 2% dilute acetic acid aqueous solution, and the deacetylation degree of chitosan is 85%; add 2 kg of glutaraldehyde to 100 kg of chitosan solution and mix and stir evenly, and finally add 0.5 kg of nano silver powder with a particle size of 100 nm, and mix and stir evenly to obtain the finished product.

[0073] Preparation Example 11: The chitosan solution is prepared by the following method:

[0074] Weigh chitosan and dissolve it in dilute acetic acid with stirring to obtain a chitosan solution with a mass fraction of 1%. The dilute acetic acid is a dilute acetic acid aqueous solution with a mass fraction of 2%, and the deacetylation degree of chitosan is 85%. Add 1 kg of glutaraldehyde to 100 kg of the chitosan solution and mix well with stirring. Finally, add 0.1 kg of silver nanoparticles with a particle size of 100 nm, and mix well with stirring to obtain the finished product.

[0075] Preparation Example 12: The chitosan solution was prepared by the following method:

[0076] Weigh chitosan and dissolve it in dilute acetic acid with stirring to obtain a chitosan solution with a mass fraction of 5%. The dilute acetic acid is a dilute acetic acid aqueous solution with a mass fraction of 2%, and the deacetylation degree of chitosan is 85%. Add 3 kg of glutaraldehyde to 100 kg of the chitosan solution and mix well with stirring. Finally, add 1 kg of silver nanoparticles with a particle size of 100 nm, and mix well with stirring to obtain the finished product.

[0077] Example

[0078] Example 1: A method for preparing a soft polypropylene non-woven fabric:

[0079] S1. Weigh 47 kg of polypropylene, 50 kg of elastomer, 2 kg of soft masterbatch, and 1 kg of the matte white prepared in Preparation Example 7, and mix them. The elastomer is POE, and the soft masterbatch is composed of erucic acid amide, PP, and polypropylene wax with a mass ratio of 1:1:2. Heat and melt at 230 °C, filter with a pore size of 300 mesh, then set the cold air volume to 8000 m 3 / min, the temperature to 15 °C, the humidity to 65%, and the wind speed to 1 m / s for spinning and cooling. Then set the air pressure to 0.1 MPa, the traction air flow speed to 8000 m / min, and the filament speed to 3000 m / min for air stretching. The fiber fineness is 16 - 18 μm to obtain the first fiber filament;

[0080] S2. Weigh 77 kg of polypropylene, 20 kg of elastomer, 2 kg of soft masterbatch, and 1 kg of the matte white prepared in Preparation Example 7, and mix them; Heat and melt at 230 °C, filter with a pore size of 300 mesh, then set the cold air volume to 8000 m 3 / min, the temperature to 15 °C, the humidity to 65%, and the wind speed to 1 m / s for spinning and cooling. Then set the air pressure to 0.1 MPa, the traction air flow speed to 8000 m / min, and the filament speed to 3000 m / min for air stretching. The fiber fineness is 16 - 18 μm to obtain the second fiber filament;

[0081] S3. Weigh 77 kg of polypropylene, 20 kg of elastomer, 2 kg of soft masterbatch, and 1 kg of the matte white prepared in Preparation Example 7, mix them; melt and heat at 230 °C, filter with a pore size of 300 mesh, then set the cold air volume to 8000 m 3 / min, the temperature is 15 °C, the humidity is 65%, the wind speed is 1 m / s, carry out spinning cooling, then set the air pressure to 0.1 MPa, the traction air flow speed to 8000 m / min, the wire speed to 3000 m / min, carry out air drawing, and the fiber fineness is 16 - 18 μm to obtain the third fiber filament;

[0082] S4. Lay the first fiber filament, the second fiber filament, and the third fiber filament in sequence to obtain a three - layer fiber web, then carry out hot rolling and compounding on a hot rolling machine under the conditions of a hot rolling temperature of 130 °C and a hot rolling pressure of 6.5 kPa, and then carry out post - cooling treatment, crimping, slitting, and packaging to obtain the finished product.

[0083] Example 2: The difference between this example and Example 1 is that:

[0084] In the raw materials of S1, S2, and S3, 3 kg of the modified nanocellulose prepared in Preparation Example 4 is added;

[0085] S4. Lay the first fiber filament, the second fiber filament, and the third fiber filament in sequence to obtain a three - layer fiber web. The pores formed between adjacent fiber filaments in each layer of the fiber web can pass microspheres with a particle size of 80 μm. The sodium alginate composite solution prepared in Preparation Example 1 is evenly sprayed between adjacent fiber webs, and 200 g of the sodium alginate composite solution is sprayed on each square meter of the fiber web. The sodium alginate composite solution is sprayed once, and even if some raw materials fly out of the pores, it is not sprayed again, and the sodium alginate composite solution attached to the fiber filaments in the fiber web is retained; then carry out hot rolling and compounding on a hot rolling machine under the conditions of a hot rolling temperature of 130 °C and a hot rolling pressure of 60 kPa, and finally wash 3 times with ethanol with a mass fraction of 75%, and the washing time for each time is 2 min to obtain the semi - finished product, and carry out post - cooling treatment to obtain the finished product.

[0086] Example 3: The difference between this example and Example 1 is that:

[0087] S1. Mix 50 kg of polypropylene, 45 kg of POE, 1 kg of the modified nanocellulose prepared in Preparation Example 6, 3 kg of soft masterbatch, and 1 kg of the matte white prepared in Preparation Example 9 by weight, melt and heat at 220 °C, filter with a pore size of 300 mesh, then set the cold air volume to 8000 m 3 / min, the temperature is 15°C, the humidity is 65%, the wind speed is 1 m / s, for spinning cooling, then set the air flow pressure to 0.1 MPa, the traction air flow speed to 8000 m / min, the filament speed to 3000 m / min, for air drawing, the fiber fineness is 16 - 18 μm, to obtain the first fiber filament;

[0088] S2. Weigh 75 kg of polypropylene, 22 kg of elastomer, 1 kg of the modified nano - cellulose prepared in Preparation Example 6, 1 kg of soft masterbatch, and 1 kg of the matte white prepared in Preparation Example 9, and mix them; melt - heat at 220°C, filter with a pore size of 300 mesh, then set the cold air volume to 8000 m 3 / min, the temperature is 15°C, the humidity is 65%, the wind speed is 1 m / s, for spinning cooling, then set the air flow pressure to 0.1 MPa, the traction air flow speed to 8000 m / min, the filament speed to 3000 m / min, for air drawing, the fiber fineness is 16 - 18 μm, to obtain the second fiber filament;

[0089] S3. Weigh 75 kg of polypropylene, 22 kg of elastomer, 1 kg of the modified nano - cellulose prepared in Preparation Example 6, 1 kg of soft masterbatch, and 1 kg of the matte white prepared in Preparation Example 9, and mix them; melt - heat at 220°C, filter with a pore size of 300 mesh, then set the cold air volume to 8000 m 3 / min, the temperature is 15°C, the humidity is 65%, the wind speed is 1 m / s, for spinning cooling, then set the air flow pressure to 0.1 MPa, the traction air flow speed to 8000 m / min, the filament speed to 3000 m / min, for air drawing, the fiber fineness is 16 - 18 μm, to obtain the third fiber filament;

[0090] In S4, the sodium alginate composite solution used is the sodium alginate composite solution prepared in Preparation Example 3.

[0091] Example 4: The difference between this example and Example 1 is that:

[0092] S4. Lay the first fiber filament, the second fiber filament, and the third fiber filament in sequence to obtain a three-layer fiber web. The pores formed between adjacent fiber filaments in each layer of the fiber web can pass microspheres with a particle size of 80 μm. Spray the sodium alginate composite solution prepared in Preparation Example 1 evenly between adjacent fiber webs. Spray 200 g of the sodium alginate composite solution per square meter of the fiber web. The sodium alginate composite solution is sprayed once. Even if some raw materials fly out through the pores, no re-spraying is performed, and the sodium alginate composite solution adhering to the fiber filaments in the fiber web is retained. Then, perform hot-rolling composite under the conditions of a hot-rolling temperature of 130 °C and a hot-rolling pressure of 60 kPa using a hot-rolling machine. Finally, wash with 75% by mass ethanol three times, with each washing time being 2 min to obtain a semi-finished product. Spray the chitosan solution prepared in Preparation Example 10 evenly on one side surface of the semi-finished product, then spray sepiolite evenly, and finally spray the sodium lauroyl sarcosinate solution evenly. Per square meter of the semi-finished product surface, 100 g of the chitosan solution, 60 g of sepiolite, and 100 g of the sodium lauroyl sarcosinate solution are used. The particle size of the sepiolite is 40 μm, the open porosity is 50%, and the sodium lauroyl sarcosinate is a 5% by mass aqueous solution of sodium lauroyl sarcosinate to obtain the finished product.

[0093] Example 5: The difference between this example and Example 4 is as follows:

[0094] S2. Spray the chitosan solution prepared in Preparation Example 11 evenly on one side surface of the semi-finished product, then spray sepiolite evenly, and finally spray the sodium lauroyl sarcosinate solution evenly. Per square meter of the semi-finished product surface, 100 g of the chitosan solution, 60 g of sepiolite, and 100 g of the sodium lauroyl sarcosinate solution are used. The particle size of the sepiolite is 20 μm, the open porosity is 40%, and the sodium lauroyl sarcosinate is a 5% by mass aqueous solution of sodium lauroyl sarcosinate to obtain the finished product.

[0095] Example 6: The difference between this example and Example 4 is as follows:

[0096] S2. Spray the chitosan solution prepared in Preparation Example 12 evenly on one side surface of the semi-finished product, then spray sepiolite evenly, and finally spray the sodium lauroyl sarcosinate solution evenly. Per square meter of the semi-finished product surface, 100 g of the chitosan solution, 60 g of sepiolite, and 100 g of the sodium lauroyl sarcosinate solution are used. The particle size of the sepiolite is 40 μm, the open porosity is 50%, and the sodium lauroyl sarcosinate is a 5% by mass aqueous solution of sodium lauroyl sarcosinate to obtain the finished product.

[0097] Example 7: The difference between this example and Example 2 is as follows: [[ID=ID=17]]

[0098] Ethyl cellulose microspheres and multi-porous expanded perlite are not added to the sodium alginate composite solution. ]>

[0099] Example 8: The difference between this example and Example 2 is as follows:

[0100] In the sodium alginate composite solution, expandable perlite with multi-open pores is replaced by closed-cell perlite of the same mass.

[0101] Example 9: The difference between this example and Example 2 is that:

[0102] During the preparation process of expandable perlite with multi-open pores in the sodium alginate composite solution, silica is not added.

[0103] Example 10: The difference between this example and Example 4 is that:

[0104] Sodium lauroyl sarcosinate solution is not sprayed on the surface of the semi-finished product.

[0105] Example 11: The difference between this example and Example 4 is that:

[0106] Chitosan solution and sepiolite are not sprayed on the surface of the semi-finished product.

[0107] Example 12: The difference between this example and Example 4 is that:

[0108] On the surface of the semi-finished product, sepiolite is replaced by closed-cell perlite of the same mass, and the particle size of the closed-cell perlite is 40 μm.

[0109] Example 13: The difference between this comparative example and Example 2 is that:

[0110] Modified nanocellulose and POE are not added to the raw materials.

[0111] Example 14: The difference between this comparative example and Example 2 is that:

[0112] In the raw materials, commercially available nanocellulose whiskers are used to replace the modified nanocellulose with the same mass, and commercially available matting white particles are used to replace the matting white with the same mass, that is, no materials are loaded on the surfaces of the nanocellulose whiskers and the matting white particles.

[0113] Example 15: The difference between this comparative example and Example 2 is that:

[0114] S2. Lay the fiber filaments to form a three-layer fiber web, and then use a hot rolling machine to perform hot rolling and compounding under the conditions of a hot rolling temperature of 130 °C and a hot rolling pressure of 60 kPa to obtain the finished product.

[0115] Performance detection test

[0116] 1. Air permeability detection

[0117] The finished polypropylene non-woven fabrics were prepared by using the preparation methods of Examples 1-12 and 15 respectively. The air permeability was detected according to GBT5453-1997, and the data were recorded. On one side of the polypropylene non-woven fabric where sepiolite was provided, the superabsorbent resin was evenly laid, and then it was blocked and fixed with ordinary non-woven fabric to simulate a diaper. 500 ml of water was poured onto the surface of the polypropylene non-woven fabric of the diaper, and after standing for 30 min, the polypropylene non-woven fabric was removed, and the air permeability was detected again, and the air permeability was recorded.

[0118] 2. Hydrophilicity detection

[0119] The finished polypropylene non-woven fabrics were prepared by using the preparation methods of Examples 1-6, 9-11 and 15 respectively. The polypropylene non-woven fabric was tested according to DB44 / T1872-2016. The smaller the contact angle, the better the surface wettability and the better the hydrophilicity.

[0120] 3. Flexibility detection

[0121] The finished polypropylene non-woven fabrics were prepared by using the preparation methods of Examples 1-3 and Examples 13-14 respectively. The transverse softness was detected according to GB / T8942-2016, and the data were recorded.

[0122] 4. Tensile strength detection

[0123] The finished polypropylene non-woven fabrics were prepared by using the preparation methods of Example 2, Example 4 and Comparative Example 2 respectively. The transverse tensile strength was detected according to GB / T12914-2018, and the data were recorded.

[0124] 5. Re-permeability detection

[0125] The finished polypropylene non-woven fabrics were prepared by using the preparation methods of Examples 1-6 and 10 respectively. On one side of the polypropylene non-woven fabric where sepiolite was provided, the superabsorbent resin (the maximum water absorption of the superabsorbent resin is 500 mL) was evenly laid, and then it was blocked and fixed with ordinary non-woven fabric to simulate a diaper. 500 ml of water was poured onto the surface of the polypropylene non-woven fabric of the diaper, and after standing for 30 min, the polypropylene non-woven fabric was removed, and it was recorded as weight A;

[0126] On one side of the polypropylene non-woven fabric where sepiolite was provided, the superabsorbent resin (the maximum water absorption of the superabsorbent resin is 500 mL) was evenly laid, and then it was blocked and fixed with ordinary non-woven fabric to simulate a diaper. 500 ml of water was poured onto the surface of the polypropylene non-woven fabric of the diaper, and after standing for 30 min, then 100 mL of water was continuously poured on the side of the diaper where the ordinary non-woven fabric was provided, and then the weight of the polypropylene non-woven fabric was recorded, and it was recorded as weight B; Calculate the weight difference = weight B - weight A.

[0127] Table 1 Performance test table:

[0128]

[0129] From Example 1 and Examples 2-3 and Table 1, it can be seen that the polypropylene non-woven fabric prepared in the present application has good air permeability and is hydrophilic and soft. After being made into diapers, it still has good air permeability even after absorbing urine.

[0130] Combining Example 2 and Examples 4-6 with Table 1, it can be seen that the hydrophilicity of the polypropylene non-woven fabric after post-treatment is increased, indicating that the combination of sodium alginate composite liquid, chitosan liquid, sepiolite, and sodium lauroyl sarcosine solution can improve the hydrophilicity of the finished polypropylene non-woven fabric. Although the air permeability is slightly reduced, it is still at a good level of air permeability; at the same time, the tensile strength is increased, and the effect of preventing urine back seepage is better.

[0131] Combining Example 2 and Examples 7-9 with Table 1, it can be seen that ethyl cellulose microspheres and multi-porous expanded perlite were not added to the sodium alginate composite liquid in Example 7. Compared with Example 2, the air permeability of the polypropylene non-woven fabric prepared in Example 7 was worse than that in Example 2, and the air permeability after moisture absorption was also worse than that in Example 2; this indicates that after washing with ethanol, the ethyl cellulose microspheres can be separated from the sodium alginate network, and the volume originally occupied by the ethyl cellulose microspheres is vacated, which further increases the porosity of the sodium alginate network. In addition, the pores inside the multi-porous expanded perlite are hydrophobic and are not easily affected by the absorbed moisture, thereby ensuring the air permeability of the pores after moisture absorption.

[0132] In Example 8, the open-pore expanded perlite was replaced with closed-pore perlite of equal mass in the sodium alginate composite liquid. Compared with Example 2, the air permeability of the polypropylene non-woven fabric prepared in Example 8 was worse than that in Example 2, and the air permeability after moisture absorption was also worse than that in Example 2, indicating that the closed-pore perlite could not utilize the pore structure for air permeability, thereby affecting the air permeability of the finished polypropylene non-woven fabric.

[0133] In the preparation process of the multi-open porous expanded perlite in the sodium alginate composite liquid in Example 9, no silicon dioxide was added. Compared with Example 2, the contact angle of the polypropylene non-woven fabric prepared in Example 9 was greater than that in Example 2, indicating that the addition of silicon dioxide promotes the hydrophilicity of the multi-open porous expanded perlite, thereby improving the hydrophilicity of the polypropylene non-woven fabric.

[0134] Combining Example 4 and Examples 10-12 and Table 1, it can be seen that the surface of the semi-finished product of Example 10 is not sprayed with the sodium lauroyl sarcosinate solution. Compared with Example 4, the weight difference of the polypropylene non-woven fabric prepared in Example 10 is greater than that of Example 4; this indicates that the hydrophilic end of the sodium lauroyl sarcosinate solution is convenient for connecting with the sepiolite and chitosan solution, while the hydrophobic end faces outward, that is, the hydrophobic end is in contact with the polymer water-absorbent resin in the diaper. When the polymer water-absorbent resin absorbs moisture, the backflow problem can be avoided as much as possible.

[0135] In Example 11, the surface of the semi-finished product was not sprayed with chitosan solution and sepiolite. Compared with Example 4, the contact angle of the polypropylene non-woven fabric prepared in Example 11 was greater than that in Example 4, indicating that the addition of chitosan solution and sepiolite can improve the hydrophilicity of the polypropylene non-woven fabric.

[0136] In Example 12, the sepiolite on the surface of the semi-finished product was replaced with closed-cell perlite of the same mass, and the particle size of the extinctor white was 40 μm. Compared with Example 4, the air permeability of the polypropylene non-woven fabric prepared in Example 12 was worse than that in Example 4, and the air permeability after moisture absorption was still worse than that in Example 4. This shows that the porous structure of sepiolite can improve the air permeability of the polypropylene non-woven fabric.

[0137] Combining Example 2 and Examples 13 - 15 and referring to Table 1, it can be seen that in Example 13, modified nanocellulose and POE were not added to the raw materials. Compared with Example 2, the flexibility of the polypropylene non-woven fabric prepared in Example 13 was worse than that in Example 2. This indicates that the addition of modified nanocellulose and POE can improve the softness of the polypropylene non-woven fabric.

[0138] In Example 14, the modified nanocellulose in the raw materials was replaced with commercially available nanocellulose whiskers of the same mass, and the extinctor white was replaced with commercially available extinctor white particles of the same mass. Compared with Example 2, the flexibility of the polypropylene non-woven fabric prepared in Example 14 was worse than that in Example 2, and the tensile strength was lower than that in Example 2. This shows that the surface treatment of modified nanocellulose and extinctor white with maleic anhydride grafted POE can improve the bonding compatibility of nanocellulose, extinctor white and raw materials such as polypropylene, thereby improving the mechanical strength and flexibility at the same time.

[0139] In Example 15, the surface of the fiber web was not sprayed with sodium alginate composite solution. Compared with Example 2, the air permeability of the polypropylene non-woven fabric prepared in Example 15 was worse than that in Example 2, and the contact angle was greater than that in Example 2. This indicates that the addition of sodium alginate composite solution can form a network to improve air permeability, and can also utilize the hydrophilicity of sodium alginate to improve the hydrophilicity of the polypropylene non-woven fabric.

[0140] This specific embodiment is only an explanation of the present application, and it is not a limitation of the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A method for preparing a soft polypropylene non-woven fabric, characterized in that: The steps include: S1. Weigh 45-50 parts of polypropylene, 45-50 parts of elastomer, 1-3 parts of soft masterbatch, and 0.5-1 part of matte white, mix them, and melt-extrude, spin, and stretch them to produce a first fiber yarn; S2. Weigh 75-80 parts of polypropylene, 18-22 parts of elastomer, 1-3 parts of soft masterbatch, and 0.5-1 part of matte white, mix them, and melt-extrude, spin, and stretch them to produce a second fiber. S3. Weigh 75-80 parts of polypropylene, 18-22 parts of elastomer, 1-3 parts of soft masterbatch, and 0.5-1 part of matte white, mix them, and then melt extrude, spin, and stretch them to produce a third fiber. S4. Lay the first fiber filaments, the second fiber filaments, and the third fiber filaments in sequence to obtain a first fiber web, a second fiber web, and a third fiber web, which are then hot-rolled, post-treated, curled, slit, and packaged to obtain a finished product; sodium alginate composite liquid is evenly sprayed between the first fiber web, the second fiber web, and the third fiber web, and then hot-rolled composite and ethanol washed to obtain a semi-finished product; further post-treated, curled, slit, and packaged to obtain a finished product; the sodium alginate composite liquid is composed of sodium alginate, ethyl cellulose microspheres, multi-porous expanded perlite, and water in a mass ratio of 1:0.2-0.4:1-2:100-120; the matte white particle size is less than 500nm; the specific steps of post-treatment are as follows: chitosan solution, sepiolite, and sodium lauroyl sarcosine solution are evenly sprayed on the surface of one side of the semi-finished product in sequence, and dried.

2. The method for preparing a soft polypropylene non-woven fabric according to claim 1, wherein: The particle size of the ethyl cellulose microspheres is 20-40 μm.

3. The method for preparing a soft polypropylene non-woven fabric according to claim 1, wherein: The multi-porous expanded perlite is prepared by modifying the multi-porous perlite with a silane coupling agent KH-570 and then bonding it with silicon dioxide.

4. The method for preparing a soft polypropylene non-woven fabric according to claim 1, wherein: The non-woven fabric further comprises 1-3 parts of modified nanocellulose, which is composed of nanocellulose whiskers, maleic anhydride grafted POE and nano silver powder in a mass ratio of 1:0.1-0.3:0.02-0.

1.

5. The method for preparing a soft polypropylene non-woven fabric according to claim 1, wherein: The chitosan solution is prepared by the following method: Chitosan was weighed and dissolved in dilute acetic acid with stirring to prepare a chitosan solution with a mass fraction of 1-5%, and then glutaraldehyde was added with a mass ratio of chitosan solution to glutaraldehyde of 100:1-3. Finally, nano-silver powder was added with a mass ratio of chitosan solution to nano-silver powder of 100:0.1-1, and mixed evenly to prepare a finished product.

6. The method for preparing a soft polypropylene non-woven fabric according to claim 1, characterized in that: The sepiolite has a particle size of 20-40 μm and an open porosity of not less than 40%.

7. The method for preparing a soft polypropylene non-woven fabric according to claim 1, characterized in that: The melting temperature in S1 is 220-230°C.

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