Superfine fiber leakage-proof non-woven fabric for buccal cigarette and manufacturing process thereof

Abstract

The invention relates to the technical field of high-molecular polymers, in particular to a superfine fiber leakage-proof non-woven fabric for buccal cigarettes, which is characterized in that polyester-based superfine fibers and nylon 6 superfine fibers are combined according to a specific proportion, so that solid particles are effectively intercepted while a compact network structure is formed, and the leakage-proof performance of the superfine fibers is improved. Through micro capillary channels formed by size difference and arrangement of fibers, after the coarse fiber layer is in contact with saliva, liquid is rapidly absorbed and transferred, the coarse fiber layer becomes a'moisture guiding channel 'for rapidly wetting powder, and the surface grafting modified polyester-based superfine fibers optimize the hydrophilicity and surface energy of a fiber network, so that the moisture permeability of the powder is improved. Saliva is promoted to rapidly and uniformly infiltrate the whole fiber web and contained buccal cigarette powder, it is ensured that the powder is uniformly and rapidly permeated by the saliva, the contact area is maximized, dissolution and diffusion of nicotine and flavor substances are accelerated, friction between fibers is reduced through magnesium stearate, flowing resistance of liquid on the surfaces of the fibers is reduced, and smoothness of the seepage process is assisted.

Description

Technical Field

[0001] The present invention relates to the technical field of high molecular polymers, and in particular to an ultra-fine fiber leak-proof non-woven fabric for buccal cigarettes and a manufacturing process thereof. Background Art

[0002] The World Health Organization's Framework Convention on Tobacco Control has introduced prohibitions on the spread of tobacco smoke in public places, which has had a strong impact on traditional tobacco products. Against this backdrop, the tobacco industry around the world has regarded the research and development of smokeless tobacco products as an important means to solve the future development of the tobacco industry. In Europe, North and South America, India and Africa, there are many varieties of smokeless tobacco products, and consumption in all countries is showing an increasing trend year by year.

[0003] Snus is a widely used smokeless tobacco product, mainly made of certain specially processed tobacco or materials containing tobacco ingredients. When placed in the mouth, the tobacco ingredients are absorbed into the blood through the oral mucosa, bringing satisfaction and pleasure. Since the entire process does not produce any smoke and is safe and controllable, it is recommended by the World Health Organization as a smoking cessation product. In Sweden, it is one of the most popular methods of quitting smoking, with a success rate of up to 60%-75%.

[0004] Currently, existing snus packaging bags generally use cellulose-based or synthetic fiber non-woven fabrics, which have significant technical drawbacks. Traditional cellulose-based materials, due to their coarse fibers and large pores, are prone to powder leakage, and their natural hydrophobicity slows nicotine dissolution. While synthetic fibers can improve leak resistance through their ultrafine structure, their high density hinders saliva penetration, and their rigidity and hydrophobic surface can cause a foreign body sensation in the mouth and delayed dissolution. Existing technologies struggle to achieve rapid dissolution while preventing powder leakage. Their reliance on chemical coatings or surface treatments introduces safety risks, making it impossible to balance core requirements such as leak resistance, dissolution efficiency, and comfort. Summary of the Invention

[0005] The present invention aims to provide a microfiber leak-proof nonwoven fabric for oral cigarettes and a manufacturing process thereof. The present invention combines polyester-based microfibers and nylon 6 microfibers in a specific ratio to form a dense network structure that effectively intercepts solid particles. At the same time, through a gradient structure fiber web composed of a coarse fiber layer, a transition layer, and a microfiber leak-proof layer, the coarse fiber layer quickly absorbs and transfers liquid after contact with saliva, becoming a "wet-conducting channel" for quickly wetting the powder. The surface-grafted modified polyester-based microfibers optimize the hydrophilicity and surface energy of the fiber network, promoting saliva to quickly and evenly infiltrate the entire fiber web and the oral cigarette powder contained therein, ensuring that the powder is evenly and quickly penetrated by saliva, maximizing the contact area, and accelerating the dissolution and diffusion of nicotine and flavor substances. Magnesium stearate reduces friction between fibers, lowers the resistance of liquid flow on the fiber surface, and assists in the smoothness of the exudation process.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: a microfiber leak-proof non-woven fabric for oral cigarettes, the microfiber leak-proof non-woven fabric is composed of the following components in percentage by mass:

[0007] Polyester-based microfiber 60% to 85%;

[0008] Nylon 6 microfiber 8% to 22%;

[0009] Polylactic acid-polyethylene glycol block copolymer 4% to 7%;

[0010] Nano-silicon dioxide particles 0.5% to 2%;

[0011] Magnesium stearate 0.3%~1%.

[0012] Furthermore, the polyester-based ultrafine fiber is a modified polyethylene terephthalate with polyethyleneimine grafted on the surface, the grafting rate is 0.1% to 0.5%, and the molar ratio of ethylene glycol segments to terephthalic acid segments in the modified polyethylene terephthalate is 1.15:1.

[0013] Furthermore, the particle size of the nano-silica particles is 10 nm to 30 nm, and the surface of the nano-silica particles is modified by γ-aminopropyltriethoxysilane, and the hydroxyl coverage thereof is 60% to 85%.

[0014] Furthermore, the average diameter of the polyester-based ultrafine fibers is 0.5 dtex to 0.8 dtex, and the average diameter of the nylon 6 ultrafine fibers is 0.4 dtex to 0.7 dtex.

[0015] A manufacturing process for a microfiber leak-proof nonwoven fabric for oral cigarettes comprises the following steps:

[0016] Step 1: Nano-silica particles and magnesium stearate are mixed in a mass ratio of 3:1 at 40° C. to 50° C., anhydrous ethanol is added to form a suspension with a solid content of 5% to 8%, and the suspension is dispersed in an ultrasonic reactor for 15 to 20 minutes. The suspension is then circulated through a high-pressure microfluidizer at a pressure of 150 MPa to 200 MPa for 3 to 5 times to obtain a stable functional nano pre-dispersion liquid;

[0017] Step 2: placing polyester-based microfibers and nylon 6 microfibers in a mass ratio of 7:1 in a high-speed vortex mixer, using nitrogen as a carrier gas, and high-speed shear mixing for 10 min to 15 min at a negative pressure of 0.05 MPa to 0.08 MPa to obtain a mixed fiber bundle;

[0018] Step 3: The nano pre-dispersion obtained in step 1 is evenly sprayed into the mixed fiber bundle obtained in step 2 through an atomizing nozzle, and polylactic acid-polyethylene glycol block copolymer particles are added at the same time. The mixture is blended and melted in a twin-screw extruder and then extruded through a spinneret with a pore size of 0.15 mm to 0.25 mm. The extruded melt stream is cooled, pulled and drawn to obtain a composite ultrafine fiber;

[0019] Step 4: The composite ultrafine fibers are fed into three groups of vertically arranged electrospinning devices. An independent high-voltage electric field is applied to each group. The composite ultrafine fibers are deposited on a conveyor belt at a speed of 0.8 to 1.2 m / min to form a gradient structure fiber web consisting of a coarse fiber layer, a transition layer, and an ultrafine fiber leak-proof layer.

[0020] Step 5: After the gradient structure fiber web is treated by a radio frequency low-temperature plasma treatment device, it is immediately sent to a hot air bonding machine, and the hot air temperature is controlled to be 132°C ~ 138°C, the hot air adhesive wind speed is controlled to be 1.5m ~ 2.5m / s, and the residence time is 20s ~ 30s to achieve in-situ crosslinking of the interface and bonding of the low-melting point components, and finally obtain an ultrafine fiber leak-proof non-woven fabric.

[0021] Furthermore, the melt stream extruded in step 3 is sequentially drawn through the upper annular air duct, the lower convergent air duct and the ultrasonic resonance traction device arranged downstream of the cooling air ring, and then drawn through multi-stage negative pressure temperature-controlled rollers to produce composite ultrafine fibers.

[0022] Furthermore, the multi-stage negative pressure adsorption roller includes a first-stage roller and a second-stage roller, wherein the surface temperature of the first-stage roller is 40-45°C, the line speed is 1500-1800 m / min, and the negative pressure value is -0.04-0.06 MPa; wherein the surface temperature of the second-stage roller is 55-60°C, the line speed is 3800-4200 m / min, and the negative pressure value is -0.08-0.10 MPa.

[0023] Furthermore, the gradient structure fiber web is treated by a radio frequency low-temperature plasma treatment device, including: the gradient structure fiber web passes through the vacuum air lock transition chamber of the radio frequency low-temperature plasma treatment device at a uniform speed of 0.8 to 1.2 m / min, and then receives radio frequency treatment in the plasma reaction chamber. After the treatment is completed and leaves the plasma reaction chamber, it immediately enters the quenching unit, and the quenching time is 3 to 5.

[0024] The advantages of the present invention are: the present invention provides a microfiber leak-proof non-woven fabric for oral cigarettes and a manufacturing process thereof, which has the following advantages:

[0025] The present invention combines polyester-based microfibers and nylon 6 microfibers in a specific ratio to form a dense network structure that effectively intercepts solid particles. At the same time, through the gradient structure fiber web composed of a coarse fiber layer, a transition layer, and a microfiber leak-proof layer, the coarse fiber layer quickly absorbs and transfers liquid after contacting saliva, becoming a "wet-conducting channel" for quickly wetting the powder. The surface-grafted modified polyester-based microfibers optimize the hydrophilicity and surface energy of the fiber network, promote the rapid and uniform infiltration of saliva into the entire fiber web and the oral tobacco powder contained therein, ensure that the powder is evenly and quickly penetrated by saliva, maximize the contact area, and accelerate the dissolution and diffusion of nicotine and flavor substances. Magnesium stearate reduces friction between fibers, reduces the resistance of liquid flow on the fiber surface, and assists in the smoothness of the exudation process. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solution of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] Example 1: A microfiber leak-proof non-woven fabric for oral cigarettes, the microfiber leak-proof non-woven fabric is composed of the following components by mass percentage: 60% to 85% polyester-based microfibers, the polyester-based microfibers are modified polyethylene terephthalate with surface grafted polyethyleneimine (PEI), and its molecular structure is precisely controlled: its grafting rate is 0.1% to 0.5%, and PEI is covalently bonded to the PET molecular chain through an amidation reaction, giving the fiber surface permanent cationic properties; the molar ratio of ethylene glycol segment (EG) to terephthalic acid segment (TPA) is 1.15:1, which is achieved through solid-phase polycondensation of prepolymers to improve melt fluidity and reduce crystallinity; its average diameter is 0.5 dtex to 0.8 dtex, and the curl frequency is controlled to be ≤8 / cm to ensure fiber entanglement strength.

[0028] Nylon 6 microfiber 8% to 22%, nylon 6 microfiber average diameter of 0.4dtex to 0.7dtex, molecular weight distribution index PDI ≤ 1.8, glass transition temperature (Tg) of 45 to 50 ° C to adapt to the thermal bonding process.

[0029] The polylactic acid-polyethylene glycol block copolymer is 4% to 7%, the polyethylene glycol (PEG) block molecular weight is 800 to 1500, accounting for 30% to 35% of the copolymer mass ratio, and the melting point is 125 to 130° C., and is used as a thermal bonding activation component.

[0030] 0.5% to 2% of nano-silicon dioxide particles, with a particle size of 10nm to 30nm and a BET specific surface area of ​​≥200m 2 / g, its surface is modified by γ-aminopropyltriethoxysilane: the amount of modifier added is S i The O2 mass is 10% to 15%, the reaction temperature is 70 to 80°C; the hydroxyl coverage is 60% to 85%, and the Si-OH stretching vibration peak (950cm -1 ) Strength calculation.

[0031] Magnesium stearate 0.3% to 1%, magnesium stearate particle size D90 ≤ 15μm, free fatty acid content ≤ 0.5%, to avoid fiber degradation in acidic environment.

[0032] The polyester-based ultrafine fiber is a modified polyethylene terephthalate with polyethyleneimine grafted on the surface, the grafting rate is 0.1% to 0.5%, and the molar ratio of the ethylene glycol segment to the terephthalic acid segment in the modified polyethylene terephthalate is 1.15:1.

[0033] The particle size of the nano silicon dioxide particles is 10nm to 30nm. The surface of the nano silicon dioxide particles is modified by gamma-aminopropyltriethoxysilane, and the hydroxyl coverage rate is 60% to 85%.

[0034] The average diameter of the polyester-based ultrafine fibers is 0.5 dtex to 0.8 dtex, and the average diameter of the nylon 6 ultrafine fibers is 0.4 dtex to 0.7 dtex.

[0035] The present invention also provides a process for manufacturing a leak-proof microfiber nonwoven fabric for oral cigarettes, comprising the following steps:

[0036] Step 1: Preparation of functional nano pre-dispersion: Nano-silica particles and magnesium stearate are mixed in a mass ratio of 3:1 at 40°C to 50°C, and anhydrous ethanol is added to form a suspension with a solid content of 5% to 8%. A three-stage dispersion process is then adopted: first, dispersion is carried out in an ultrasonic reactor (20kHz, power density 1.2W / mL) for 15min to 20min to break up soft agglomerates; then, the dispersion is circulated through a high-pressure microfluidizer at a pressure of 150MPa to 200MPa for 3 to 5 times, with a 5-minute cooling interval between each cycle to prevent local overheating from causing the modified layer to fall off; the final suspension has an absolute value of the Zeta potential ≥35mV (pH 7.0 test) to ensure dispersion stability >72h.

[0037] Step 2: Fiber premixing: Place polyester-based microfibers and nylon 6 microfibers in a high-speed vortex mixer (blade angle 45°, gap 1.5mm) at a mass ratio of 7:1. Introduce nitrogen to replace oxygen until the residual oxygen is <100ppm, and mix at high speed under a negative pressure of 0.05MPa to 0.08MPa for 10min to 15min. The mixing process temperature should be ≤45℃ to avoid pre-melting and agglomeration of low-melting-point components, and obtain a bulkiness ≥220cm 3 / g of mixed fiber bundles.

[0038] Step 3: Melt spinning of composite ultrafine fibers: The nano pre-dispersed liquid is sprayed into the mixed fiber bundle through a dual-channel atomizing nozzle (droplet size 50-80 μm), and polylactic acid-polyethylene glycol block copolymer particles are added simultaneously. Five-zone temperature-controlled melting is implemented in a twin-screw extruder:

[0039] Temperature Zone Temperature (℃) Function Zone Ⅰ (transportation) 160～165 Fiber preheating Zone II (melting) 245～250 PET / Nylon 6 melt Zone III (mixed) 235～240 Nanodispersion injection Zone IV (homogenization) 230～235 Eliminate concentration gradients Zone V (Extrusion) 225～230 Stable extrusion pressure

[0040] The melt stream extruded from a spinneret with an aperture of 0.15mm to 0.25mm (spinneret aperture 0.15mm to 0.25mm) passes through: an upper annular air duct (10 to 15mm from the spinneret): temperature 18 to 22°C, wind speed 0.3 to 0.5m / s vertically downward, delaying surface crystallization to form a skin-core structure; a lower convergent air duct (convergence angle 30°): temperature 25 to 35°C, wind speed 50 to 70m / s blowing toward the fiber at an angle of 15 to 20° to promote axial stretching orientation; an ultrasonic resonance traction device (set 200 to 300mm downstream, with four groups of piezoelectric transducers evenly distributed circumferentially) , working frequency 28±2kHz excites fiber resonance, sound pressure intensity 120~150dB reduces drawing tension fluctuation), and then through multi-stage negative pressure temperature control drawing: first-stage roller: surface temperature 40~45℃, line speed 1500~1800m / min, negative pressure value -0.04~-0.06MPa, pre-crystallization and rough diameter control are achieved; second-stage roller: surface temperature 55~60℃, line speed 3800~4200m / min, negative pressure value -0.08~-0.10MPa, inducing β crystal formation and increasing the elongation at break to 120%~150%, finally obtaining composite ultrafine fibers.

[0041] Step 4: Gradient structure fiber web formation: The composite ultrafine fibers are fed into three groups of vertically arranged electrospinning devices, and each group is applied with an independent high-voltage electric field (upper layer +10~+15kV, middle layer 0kV, lower layer -10~-15kV), forming: upper layer (coarse fiber layer): +10~+15kV, average fiber diameter 1.2~1.5dtex; middle layer (transition layer): 0kV, fiber gradient diameter distribution (0.8~1.2dtex); lower layer (ultrafine fiber leak-proof layer): -10~-15kV, average fiber diameter 0.5~0.8dtex and containing nanoparticle enrichment area; among which the coarse fiber layer (surface density 15~20g / m 2 , porosity 85% to 90%): as saliva diversion layer; transition layer (surface density 30 to 40 g / m 2 , porosity 70% to 75%) is a pore size gradient change layer; ultrafine fiber leak-proof layer (surface density 25 to 35g / m 2 , porosity 40% to 45%) is the main barrier for particle retention.

[0042] Step 5: Interface strengthening and consolidation: The gradient structure fiber web is treated by a radio frequency low-temperature plasma treatment device. The gradient structure fiber web passes through the vacuum gas lock transition chamber of the radio frequency low-temperature plasma treatment device at a uniform speed of 0.8 to 1.2 m / min (residence time 5 to 8 s), and then receives radio frequency treatment in the plasma reaction chamber (the distance between the gradient structure fiber web and the upper electrode is 50 to 80 mm). After the treatment is completed and leaves the plasma reaction chamber, it immediately enters the quenching unit for 3 to 5 seconds. It is then immediately sent to the hot air bonding machine, and the hot air temperature is controlled to be 132°C to 138°C (lower than the melting point of nylon 6 and higher than the melting point of polylactic acid-polyethylene glycol block copolymer). The wind speed of the hot air bonding machine is controlled at 1.5m to 2.5m / s, and the residence time is 20s to 30s to achieve in-situ crosslinking of the interface and bonding of the low-melting-point component, and finally obtain an ultra-fine fiber leak-proof non-woven fabric.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A microfiber leak-proof nonwoven fabric for oral cigarettes, characterized in that: The microfiber leak-proof nonwoven fabric is composed of the following components by mass percentage: Polyester-based microfiber 60% to 85%; Nylon 6 microfiber 8% to 22%; Polylactic acid-polyethylene glycol block copolymer 4% to 7%; Nano-silicon dioxide particles 0.5% to 2%; Magnesium stearate 0.3%~1%.

2. The leak-proof microfiber nonwoven fabric for buccal cigarette according to claim 1, characterized in that: The polyester-based ultrafine fiber is a modified polyethylene terephthalate with polyethyleneimine grafted on the surface, the grafting rate is 0.1% to 0.5%, and the molar ratio of the ethylene glycol segment to the terephthalic acid segment in the modified polyethylene terephthalate is 1.15:

1.

3. The leak-proof microfiber nonwoven fabric for buccal cigarette according to claim 1, characterized in that: The particle size of the nano silicon dioxide particles is 10nm to 30nm. The surface of the nano silicon dioxide particles is modified by gamma-aminopropyltriethoxysilane, and the hydroxyl coverage rate is 60% to 85%.

4. The leak-proof microfiber nonwoven fabric for buccal cigarette according to claim 1, characterized in that: The average diameter of the polyester-based ultrafine fibers is 0.5 dtex to 0.8 dtex, and the average diameter of the nylon 6 ultrafine fibers is 0.4 dtex to 0.7 dtex.

5. A process for manufacturing a leak-proof microfiber nonwoven fabric for oral cigarettes, characterized in that: The following steps are involved: Step 1: Nano-silica particles and magnesium stearate are mixed in a mass ratio of 3:1 at 40° C. to 50° C., anhydrous ethanol is added to form a suspension with a solid content of 5% to 8%, and the suspension is dispersed in an ultrasonic reactor for 15 to 20 minutes. The suspension is then circulated through a high-pressure microfluidizer at a pressure of 150 MPa to 200 MPa for 3 to 5 times to obtain a stable functional nano pre-dispersion liquid; Step 2: placing polyester-based microfibers and nylon 6 microfibers in a mass ratio of 7:1 in a high-speed vortex mixer, using nitrogen as a carrier gas, and high-speed shear mixing for 10 min to 15 min at a negative pressure of 0.05 MPa to 0.08 MPa to obtain a mixed fiber bundle; Step 3: The nano pre-dispersion obtained in step 1 is evenly sprayed into the mixed fiber bundle obtained in step 2 through an atomizing nozzle, and polylactic acid-polyethylene glycol block copolymer particles are added at the same time. The mixture is blended and melted in a twin-screw extruder and then extruded through a spinneret with a pore size of 0.15 mm to 0.25 mm. The extruded melt stream is cooled, pulled and drawn to obtain a composite ultrafine fiber; Step 4: The composite ultrafine fibers are fed into three groups of vertically arranged electrospinning devices. An independent high-voltage electric field is applied to each group. The composite ultrafine fibers are deposited on a conveyor belt at a speed of 0.8 to 1.2 m / min to form a gradient structure fiber web consisting of a coarse fiber layer, a transition layer, and an ultrafine fiber leak-proof layer. Step 5: After the gradient structure fiber web is treated by a radio frequency low-temperature plasma treatment device, it is immediately sent to a hot air bonding machine, and the hot air temperature is controlled to be 132°C ~ 138°C, the hot air adhesive wind speed is controlled to be 1.5m ~ 2.5m / s, and the residence time is 20s ~ 30s to achieve in-situ crosslinking of the interface and bonding of the low-melting point components, and finally obtain an ultrafine fiber leak-proof non-woven fabric.

6. The manufacturing process of the microfiber leak-proof nonwoven fabric for buccal cigarette according to claim 5, characterized in that: The melt stream extruded in step 3 is sequentially drawn through the upper annular air duct, the lower convergent air duct and the ultrasonic resonance drawing device arranged downstream of the cooling air ring, and then drawn through multi-stage negative pressure temperature-controlled rollers to produce composite ultrafine fibers.

7. The process for manufacturing a leak-proof microfiber nonwoven fabric for buccal cigarette according to claim 6, characterized in that: The multi-stage negative pressure adsorption roller includes a first-stage roller and a second-stage roller, wherein the surface temperature of the first-stage roller is 40-45°C, the line speed is 1500-1800 m / min, and the negative pressure value is -0.04-0.06 MPa; wherein the surface temperature of the second-stage roller is 55-60°C, the line speed is 3800-4200 m / min, and the negative pressure value is -0.08-0.10 MPa.

8. The process for manufacturing a leak-proof microfiber nonwoven fabric for buccal cigarette according to claim 5, characterized in that: The gradient structure fiber web is treated by a radio frequency low-temperature plasma treatment device, including: the gradient structure fiber web passes through a vacuum gas lock transition chamber of the radio frequency low-temperature plasma treatment device at a uniform speed of 0.8 to 1.2 m / min, and then receives radio frequency treatment in a plasma reaction chamber. After the treatment is completed and the fiber web leaves the plasma reaction chamber, it immediately enters a quenching unit for a quenching time of 3 to 5 seconds.