Preparation method of hollow filter stick

Abstract

The invention provides a preparation method of a hollow filter stick, which comprises the following steps: after opening diacetate fiber tows, mixing with a plasticizer, and then premixing, shaping and slitting to obtain the hollow filter stick. According to the preparation method provided by the invention, the filling uniformity of the acetate fiber tows is improved, the bonding effect of the hollow filter stick is improved, the conditions of layering, deformation and even breakage easily occurring in the use process of the hollow filter stick are avoided, meanwhile, the pattern reduction degree is high, and the attractive appearance of the filter stick is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of cigarette filter rod preparation, and specifically relates to a method for preparing a hollow filter rod, and in particular to a method for preparing a hollow filter rod with good bonding effect. Background Art

[0002] With the continuous development of cigarette filter rod technology, hollow filter rods are becoming more and more popular among consumers due to their novel appearance and easy smoking experience. Major cigarette companies have also launched hollow filter rod cigarettes with brand characteristics. During the cigarette assembly process, the washboard needs to squeeze the hollow filter rod and wrap it with cork paper. In this process, the hollow filter rod is easily delaminated, deformed or even broken after being squeezed, which seriously affects the production of cigarettes.

[0003] CN115153089A discloses a hollow filter rod tube and its preparation method and application. The hollow filter rod tube provided by the invention can enhance the heat exchange capacity of the hollow tube structure and the cooling capacity of the hollow filter rod tube by modifying the hollow filter rod tube body with a heat conductive material of a specific ratio and composition, thereby preventing the inhaled smoke from being too hot and harming the smoker. The hollow filter rod tube provided by the invention also includes a binder in the heat conductive material, which improves the adhesion between the heat conductive material and the hollow filter rod tube body, and can also achieve a multi-layer coating effect, further improving the cooling capacity; the heat conductive material also adds a flavoring substance, which can stimulate the flavoring substance while heat exchange occurs, increase the richness of the smoke aroma components, and give consumers a safer and more comfortable smoking experience.

[0004] CN111109651B discloses a method for preparing a biodegradable composite fiber glue-free hollow filter rod, which comprises the following steps: (1) selection of tow: selecting a fully biodegradable composite fiber cigarette tow with a linear density of 8-15 ktex; (2) opening: opening the tow on a commercially available improved hollow filter rod forming unit; (3) forming and cutting: the opened tow is sequentially introduced into a dry hot air section smoke gun, a cooling section smoke gun, and formed and cut to obtain a biodegradable fiber glue-free hollow filter rod. The filter rod is rolled and formed without adding any plasticizer or adhesive, thereby reducing production costs, eliminating the harm to the human body caused by trace harmful substances in the plasticizer or adhesive, and is safe and pollution-free.

[0005] CN111387546A discloses a Venturi-type hollow filter rod for heating cigarettes. The outer part of the hollow filter rod body is a relatively smooth cylindrical structure, and an axial hollow cavity is arranged inside. Along the axial direction of the hollow filter rod body, the structure of the hollow cavity presents a periodic and continuous change in cavity diameter, forming a series combination of a group of thick and thin cavities in series. When smoke passes through the cavity, the flow rate of the smoke fluid changes due to the change in the cavity structure, and the fluid state is forced to change from laminar flow to turbulent flow, which improves the heat transfer efficiency and has a good heat transfer and cooling effect. At the same time, when the smoke aerosol passes through the Venturi-type hollow filter rod, the diameter of the internal cavity part changes continuously and alternately, and the aerosol collides and condenses to release heat, further enhancing the cooling effect. When the filter rod is used to heat cigarettes, while cooling, it can not only ensure the atomization amount of smoke, but also satisfy the experience of smokers.

[0006] However, none of the above patents involve the series of problems that occur after the hollow filter rod is squeezed, nor do they provide corresponding solutions. Therefore, how to provide a method that can effectively solve the problem that the hollow filter rod is prone to delamination, deformation or even rupture after being squeezed and ensure the production of cigarettes has become an urgent problem to be solved. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for preparing a hollow filter rod, and in particular to provide a method for preparing a hollow filter rod with good bonding effect. The preparation method provided by the present invention improves the uniformity of filling of acetate fiber tow, improves the bonding effect of the hollow filter rod, avoids the delamination, deformation and even rupture of the hollow filter rod during use, and at the same time has a high degree of pattern restoration, thereby improving the aesthetic performance of the filter rod.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for preparing a hollow filter rod, the method comprising the following steps:

[0010] After the diacetate fiber tow is opened, it is mixed with a plasticizer, and then premixed, shaped, and cut to obtain the hollow filter rod.

[0011] The above method can effectively improve the uniformity of filling of the acetate fiber tow by premixing the diacetate fiber tow and the plasticizer. The combination of the plasticizer can improve the bonding effect of the hollow filter rod, thereby avoiding the delamination, deformation and even rupture of the hollow filter rod during use. At the same time, the pattern on the bottom of the filter rod is highly restored, thereby improving the aesthetic appearance of the filter rod.

[0012] Preferably, the plasticizer includes any one of triacetin, polyethylene glycol, triethylene glycol diacetate or triethyl citrate, or a combination of at least two thereof.

[0013] Preferably, the plasticizer comprises a combination of triacetin, polyethylene glycol and triethylene glycol diacetate.

[0014] The above-mentioned specific plasticizer combination can effectively improve the bonding effect of the hollow filter rod, and avoid the delamination, deformation and even rupture of the hollow filter rod that are prone to occur during use.

[0015] Preferably, the mass ratio of triacetin, polyethylene glycol and triethylene glycol diacetate is (4-8):(1-3):(1-3), wherein the number of triacetin can be 4, 5, 6, 7 or 8, the number of polyethylene glycol can be 1, 1.5, 2, 2.5 or 3, and the number of triethylene glycol diacetate can be 1, 1.5, 2, 2.5 or 3, but are not limited to the values ​​listed above. Other values ​​not listed within the above numerical range are also applicable.

[0016] Preferably, the mass of the plasticizer is 10-30% of the mass of the diacetate fiber bundle, such as 10%, 15%, 20%, 25% or 30%, etc., but is not limited to the values ​​listed above, and other values ​​not listed within the above numerical range are also applicable.

[0017] Preferably, the plasticizer is kept warm before use, and the keeping temperature is 30-60°C, for example, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C, etc., but is not limited to the above-listed values, and other values ​​not listed within the above numerical range are also applicable.

[0018] Preferably, the premixing is performed using a tow premixing device, and the tow premixing device comprises an upper bundling roller and a lower bundling roller.

[0019] Preferably, the opening angle of the upper bundling roller is 90°-150°, for example 90°, 100°, 110°, 120°, 130°, 140° or 150°, but is not limited to the values ​​listed above, and other values ​​not listed within the above numerical range are also applicable.

[0020] Preferably, the opening angle of the lower bundling roller is 30°-90°, for example 30°, 40°, 50°, 60°, 70°, 80° or 90°, but is not limited to the values ​​listed above, and other values ​​not listed within the above numerical range are also applicable.

[0021] Preferably, the opening angle of the lower bundling roller is smaller than the opening angle of the upper bundling roller.

[0022] Preferably, the width of the upper bundling roller is 15-30 cm, for example 15 cm, 16 cm, 17 cm, 18 cm, 19 cm, 20 cm, 21 cm, 22 cm, 23 cm, 24 cm, 25 cm, 26 cm, 27 cm, 28 cm, 29 cm or 30 cm, but is not limited to the values ​​listed above, and other values ​​not listed within the above numerical range are also applicable.

[0023] Preferably, the width of the lower bundling roller is 5-15 cm, for example 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm, 11 cm, 12 cm, 13 cm, 14 cm or 15 cm, but is not limited to the values ​​listed above, and other values ​​not listed within the above numerical range are also applicable.

[0024] Preferably, the width of the upper bundling roller is not less than the width of the lower bundling roller.

[0025] The above-mentioned specific tow premixing device and its parameter setting can bundle the tows with a larger width after opening, effectively improve the uniformity of tow filling, and thus improve the bonding effect; in addition, the opening angle of the upper bundling roller is greater than the opening angle of the lower bundling roller. The tows after opening first pass through the upper bundling roller and then through the lower bundling roller to be sent to the wire catcher, which can realize the step-by-step gathering of the tows, avoid the tows with a larger opening width from overflowing the bundling roller, and improve the bonding effect.

[0026] Preferably, the upper bundling roller and the lower bundling roller are made of anti-adhesion materials (such as stainless steel or aluminum materials) and are subjected to anti-adhesion treatment (such as polishing, anti-adhesion coating), and these process treatments can effectively prevent the filament bundles from sticking.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention provides a method for preparing a hollow filter rod. By premixing a diacetate fiber tow with a plasticizer after mixing, the uniformity of filling the acetate fiber tow can be effectively improved. The combination of the plasticizer can improve the bonding effect of the hollow filter rod, thereby avoiding the delamination, deformation and even rupture of the hollow filter rod that are prone to occur during use. At the same time, the pattern on the bottom of the filter rod has a high degree of restoration, thereby improving the aesthetic performance of the filter rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the production device in Example 1-3;

[0030] Figure 2 is a schematic structural diagram of the tow premixing device in Examples 1-3;

[0031] Wherein 1-first air opening device, 2-second air opening device, 3-stabilizing roller, 4-first opening roller, 5-second opening roller, 6-third air opening device, 7-plasticizer spraying device, 8-output roller, 9-tow premixing device, 10-tow catcher, 11-heating module, 12-cooling module, 13-molding smoke gun, 14-slitting device, 91-upper bunching roller, 92-first synchronous pulley, 93-synchronous belt, 94-lower bunching roller, 95-second synchronous pulley, 96-servo motor, 97-displacement platform;

[0032] Figure 3 is a scanning electron microscope image of the hollow filter rod prepared in Example 1;

[0033] Figure 4 This is a scanning electron microscope image of the hollow filter rod prepared in Comparative Example 1. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0035] In the following examples, triethylene glycol diacetate and polyethylene glycol were purchased from Zhengzhou Xinqiao Tobacco Service Co., Ltd., and triacetin was purchased from Jiangsu Raymond New Materials Co., Ltd., wherein the purity of triacetin and triethylene glycol diacetate is ≥99%, and the molecular weight of polyethylene glycol is 200-800.

[0036] Example 1

[0037] This embodiment provides a method for preparing a hollow filter rod, using Figure 1 The production device shown is prepared, 1 is the first air opening device, 2 is the second air opening device, 3 is the stabilizing roller, 4 is the first opening roller, 5 is the second opening roller, 6 is the third air opening device, 7 is the plasticizer spraying device, 8 is the output roller, 9 is the tow premixing device, 10 is the wire catcher, 11 is the heating module, 12 is the cooling module, 13 is the molding smoke gun, and 14 is the slitting device.

[0038] After the diacetate fiber tow is opened by the three-pass air opening device 1, 2, 6 and the opening rollers 4, 5, the plasticizer spraying device 7 sprays the plasticizer on the opened diacetate fiber tow, the output roller 8 sends the tow to the tow premixing device 9 for mixing, and the wire catcher 10 sends the tow to the heating module 11 for shaping, and the corresponding hollow pattern is generated by the core rod of a specific shape placed in the heating module 11, and the core rod is solidified into a filter rod by the cooling module 12, and is sent to the slitting device 14 through the forming smoke gun 13 to be slit into hollow filter rods, and the end surface pattern of the hollow filter rod is detected by the hollow filter rod end surface visual detection device, and the hollow filter rod with poor end surface pattern restoration is eliminated.

[0039] The plasticizer is triacetin, polyethylene glycol and triethylene glycol diacetate (mass ratio 7:2:2), the amount of plasticizer applied is 25%, and each plasticizer component is stirred and mixed under heating conditions of 40°C before use, and stored in a large plasticizer box of the molding equipment. The large plasticizer box has a stirring paddle and a heating device to ensure the uniformity of the mixed solution. The mixed solution is sucked into a small plasticizer box using a suction pump, and a vacuum pump is used for exhaust treatment to prevent bubbles from existing in the mixed solution, which affects the uniformity of the plasticizer spraying. The mixed solution is evenly sprayed on the diacetate fiber bundle after opening through a heating nozzle through a suction pump. The large and small plasticizer boxes, nozzles and pipelines all need to be heat-insulated (60°C).

[0040] The structure of the tow premixing device is as follows Figure 2 As shown, it consists of an upper bundling roller 91, a lower bundling roller 94, a first synchronous pulley 92, a second synchronous pulley 95, a synchronous belt 93, a servo motor 96 and a displacement platform 97, wherein the opening angle α of the upper bundling roller is 120° and the width is 20 cm, and the opening angle β of the lower bundling roller is 60° and the width is 10 cm; the upper and lower bundling rollers are made of stainless steel, the surface is polished and coated with polytetrafluoroethylene to prevent the bundles from sticking; the upper and lower bundling rollers are driven by synchronous pulleys 92 and 95, and the synchronous pulleys are driven by a servo motor 96, and the electrical signal of the servo motor 96 is read by the encoder The signal of the main motor controls the motor speed to ensure that the linear speed of the bundling roller is consistent with the linear speed of the main motor.

[0041] Scanning electron microscopy was used to observe the fiber bonding in the hollow filter rod ( Figure 3 ), it can be seen that effective bonding occurs.

[0042] Example 2

[0043] This embodiment provides a method for preparing a hollow filter rod, using Figure 1 The production device shown is prepared, 1 is the first air opening device, 2 is the second air opening device, 3 is the stabilizing roller, 4 is the first opening roller, 5 is the second opening roller, 6 is the third air opening device, 7 is the plasticizer spraying device, 8 is the output roller, 9 is the tow premixing device, 10 is the wire catcher, 11 is the heating module, 12 is the cooling module, 13 is the molding smoke gun, and 14 is the slitting device.

[0044] After the diacetate fiber tow is opened by the three-pass air opening device 1, 2, 6 and the opening rollers 4, 5, the plasticizer spraying device 7 sprays the plasticizer on the opened diacetate fiber tow, the output roller 8 sends the tow to the tow premixing device 9 for mixing, and the wire catcher 10 sends the tow to the heating module 11 for shaping, and the corresponding hollow pattern is generated by the core rod of a specific shape placed in the heating module 11, and the core rod is solidified into a filter rod by the cooling module 12, and is sent to the slitting device 14 through the forming smoke gun 13 to be slit into hollow filter rods, and the end surface pattern of the hollow filter rod is detected by the hollow filter rod end surface visual detection device, and the hollow filter rod with poor end surface pattern restoration is eliminated.

[0045] The plasticizer is triacetin, polyethylene glycol and triethylene glycol diacetate (mass ratio 8:1:1), the amount of plasticizer applied is 10%, and each plasticizer component is stirred and mixed under heating conditions at 30°C before use, and stored in a large plasticizer box of the molding equipment. The large plasticizer box has a stirring paddle and a heating device to ensure the uniformity of the mixed solution. The mixed solution is sucked into a small plasticizer box using a suction pump, and a vacuum pump is used for exhaust treatment to prevent bubbles from existing in the mixed solution, which affects the uniformity of the plasticizer spraying. The mixed solution is evenly sprayed on the diacetate fiber bundle after opening through a heating nozzle through a suction pump. The large and small plasticizer boxes, nozzles and pipelines all need to be heat-insulated (40°C).

[0046] The structure of the tow premixing device is as follows Figure 2 As shown, it consists of an upper bundling roller 91, a lower bundling roller 94, a first synchronous pulley 92, a second synchronous pulley 95, a synchronous belt 93, a servo motor 96 and a displacement platform 97, wherein the opening angle α of the upper bundling roller is 90° and the width is 15 cm, and the opening angle β of the lower bundling roller is 30° and the width is 15 cm; the upper and lower bundling rollers are made of aluminum material, the surface is polished and coated with polytetrafluoroethylene to prevent the bundles from sticking; the upper and lower bundling rollers are driven by synchronous pulleys 92 and 95, and the synchronous pulleys are driven by a servo motor 96, and the electrical signal of the servo motor 96 is read by the encoder to control the motor speed by the main motor signal to ensure that the linear speed of the bundling roller is consistent with the linear speed of the main motor.

[0047] Example 3

[0048] This embodiment provides a method for preparing a hollow filter rod, using Figure 1 The production device shown is prepared, 1 is the first air opening device, 2 is the second air opening device, 3 is the stabilizing roller, 4 is the first opening roller, 5 is the second opening roller, 6 is the third air opening device, 7 is the plasticizer spraying device, 8 is the output roller, 9 is the tow premixing device, 10 is the wire catcher, 11 is the heating module, 12 is the cooling module, 13 is the molding smoke gun, and 14 is the slitting device.

[0049] After the diacetate fiber tow is opened by the three-pass air opening device 1, 2, 6 and the opening rollers 4, 5, the plasticizer spraying device 7 sprays the plasticizer on the opened diacetate fiber tow, the output roller 8 sends the tow to the tow premixing device 9 for mixing, and the wire catcher 10 sends the tow to the heating module 11 for shaping, and the corresponding hollow pattern is generated by the core rod of a specific shape placed in the heating module 11, and the core rod is solidified into a filter rod by the cooling module 12, and is sent to the slitting device 14 through the forming smoke gun 13 to be slit into hollow filter rods, and the end surface pattern of the hollow filter rod is detected by the hollow filter rod end surface visual detection device, and the hollow filter rod with poor end surface pattern restoration is eliminated.

[0050] The plasticizer is triacetin, polyethylene glycol and triethylene glycol diacetate (mass ratio 4:3:3), the amount of plasticizer applied is 30%, and each plasticizer component is stirred and mixed under heating conditions of 60°C before use, and stored in a large plasticizer box of the molding equipment. The large plasticizer box has a stirring paddle and a heating device to ensure the uniformity of the mixed solution. The mixed solution is sucked into a small plasticizer box using a suction pump, and a vacuum pump is used for exhaust treatment to prevent bubbles from existing in the mixed solution, which affects the uniformity of the plasticizer spraying. The mixed solution is evenly sprayed on the diacetate fiber bundle after opening through a heating nozzle through a suction pump. The large and small plasticizer boxes, nozzles and pipelines all need to be heat-insulated (70°C).

[0051] The structure of the tow premixing device is as follows Figure 2 As shown, it consists of an upper bundling roller 91, a lower bundling roller 94, a first synchronous pulley 92, a second synchronous pulley 95, a synchronous belt 93, a servo motor 96 and a displacement platform 97, wherein the opening angle α of the upper bundling roller is 150° and the width is 30 cm, and the opening angle β of the lower bundling roller is 90° and the width is 15 cm; the upper and lower bundling rollers are made of aluminum material, the surface is polished and coated with polytetrafluoroethylene to prevent the bundles from sticking; the upper and lower bundling rollers are driven by synchronous pulleys 92 and 95, and the synchronous pulleys are driven by a servo motor 96, and the electrical signal of the servo motor 96 is read by the encoder to control the motor speed by the main motor signal to ensure that the linear speed of the bundling roller is consistent with the linear speed of the main motor.

[0052] Example 4

[0053] This embodiment provides a method for preparing a hollow filter rod, which is consistent with the method of embodiment 1 except that the plasticizer does not contain triacetin and the reduced portion is proportionally distributed to polyethylene glycol and triethylene glycol diacetate.

[0054] Example 5

[0055] This embodiment provides a method for preparing a hollow filter rod, which is consistent with the method of embodiment 1 except that the plasticizer does not contain polyethylene glycol and the reduced portion is proportionally distributed to triacetin and triethylene glycol diacetate.

[0056] Example 6

[0057] This embodiment provides a method for preparing a hollow filter rod, which is consistent with the method of embodiment 1 except that triethylene glycol diacetate is not included in the plasticizer and the reduced portion is proportionally distributed to polyethylene glycol and triacetin.

[0058] Example 7

[0059] This embodiment provides a method for preparing a hollow filter rod, which is consistent with Embodiment 1 except that the opening angle α of the upper bundling roller is 80° and the opening angle β of the lower bundling roller is 20°.

[0060] Example 8

[0061] This embodiment provides a method for preparing a hollow filter rod, which is consistent with the method of Embodiment 1 except that the opening angle α of the upper bundling roller is 160° and the opening angle β of the lower bundling roller is 100°.

[0062] Example 9

[0063] This embodiment provides a method for preparing a hollow filter rod, which is consistent with Embodiment 1 except that the opening angle α of the upper bundling roller is 80° and the opening angle β of the lower bundling roller is 90°.

[0064] Example 10

[0065] This embodiment provides a method for preparing a hollow filter rod, which is consistent with Embodiment 1 except that the width of the upper bundling roller is 10 cm and the width of the lower bundling roller is 20 cm.

[0066] Comparative Example 1

[0067] This comparative example provides a method for preparing a hollow filter rod, which is consistent with Example 1 except that there is no filament premixing device in the production device, that is, the filaments are not sent to the filament premixing device by the output roller 8, and the filaments are directly sent to the heating module 11 for shaping by the wire catcher 10 (without premixing).

[0068] Scanning electron microscopy was used to observe the fiber bonding in the hollow filter rod ( Figure 4 ), it can be seen that there is no obvious bonding.

[0069] Effect test:

[0070] Hollow filter rods were prepared by the preparation methods provided in Examples 1-10 and Comparative Example 1, and a hardness test was performed in the middle of the filter rods according to the relevant requirements of GB / T22838.6-2009. Each group had 20 rods, and the coefficient of variation of the hardness was calculated based on the test data. The uniformity of the filling of the acetate fiber tow was judged based on the test results, and the results were as follows:

[0071] Group Coefficient of variation Example 1 1.96 Example 2 1.98 Example 3 1.97 Example 4 2.16 Example 5 2.10 Example 6 2.15 Example 7 2.0 Example 8 1.99 Example 9 2.10 Example 10 2.15 Comparative Example 1 2.2

[0072] From the above data, it can be found that the method provided by the present invention can effectively improve the uniformity of acetate fiber tow filling in the hollow filter rod, and make the hardness of each position of the hollow filter rod tend to be consistent; by comparing Examples 1 and 4-10, it can be found that the present invention can further improve the uniformity of acetate fiber tow filling by adopting a specific plasticizer and controlling the premixing parameters; by comparing Example 1 and Comparative Example 1, it can be found that the present invention can effectively improve the uniformity of acetate fiber tow filling by adopting a premixing method.

[0073] Then, the pattern on the bottom of the filter rod was compared with the design pattern to compare their similarity. The hollow filter rod was inserted into the comparison module with the design pattern on the end surface to compare the similarity between the hollow filter rod pattern and the design pattern. The similarity was judged into three levels: "very similar, relatively similar, and relatively dissimilar". 9 evaluators were selected to judge the 11 examples respectively, and the highest number of votes was used as the judgment result. The results are as follows:

[0074] Group Similarity Example 1 Very similar Example 2 Very similar Example 3 Very similar Example 4 Similar Example 5 Similar Example 6 Similar Example 7 Very similar Example 8 Very similar Example 9 Similar Example 10 Similar Comparative Example 1 Less similar

[0075] From the above data, it can be found that the method provided by the present invention can effectively improve the pattern restoration degree; by comparing Examples 1 and 4-10, it can be found that the present invention can further improve the bonding effect of the hollow filter rod by adopting a specific plasticizer and controlling the premixing parameters, thereby improving the pattern restoration degree and making the end face shape of the hollow filter rod consistent with the designed pattern; by comparing Example 1 and Comparative Example 1, it can be found that the present invention can effectively improve the bonding effect and improve the pattern restoration degree by adopting the premixing method.

[0076] Afterwards, hollow filter rods were prepared by the preparation methods provided in Examples 1-10 and Comparative Example 1 for cigarette production (one million cigarettes). Samples with filter rod delamination, deformation, and rupture were considered defective. The defective rate was calculated, and the results were as follows:

[0077] Group Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Defective rate (ppm) 13 15 16 46 55 53 Group Example 7 Example 8 Example 9 Example 10 Comparative Example 1 Defective rate (ppm) 19 18 46 48 168

[0078] From the above data, it can be found that the method provided by the present invention can effectively improve the bonding effect of the hollow filter rod, and reduce the delamination, deformation and even rupture of the hollow filter rod during use; by comparing Examples 1 and 4-10, it can be found that the present invention can further improve the bonding effect of the hollow filter rod by adopting a specific plasticizer and controlling the premixing parameters, and then the use effect; by comparing Example 1 and Comparative Example 1, it can be found that the present invention can effectively improve the bonding effect by adopting a premixing method, and effectively avoid the delamination, deformation and even rupture of the hollow filter rod during use.

[0079] The applicant declares that the present invention illustrates the preparation method of the hollow filter rod of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0080] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0081] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for preparing a hollow filter rod, characterized in that: The preparation method comprises the following steps: After the diacetate fiber tow is opened, it is mixed with a plasticizer, and then premixed, shaped, and cut to obtain the hollow filter rod.

2. The method for preparing a hollow filter rod according to claim 1, characterized in that: The plasticizer includes any one of triacetin, polyethylene glycol, triethylene glycol diacetate or triethyl citrate or a combination of at least two thereof.

3. The method for preparing a hollow filter rod according to claim 2, characterized in that: The plasticizer includes a combination of triacetin, polyethylene glycol and triethylene glycol diacetate.

4. The method for preparing a hollow filter rod according to claim 3, characterized in that: The mass ratio of triacetin, polyethylene glycol and triethylene glycol diacetate is (4-8):(1-3):(1-3).

5. The method for preparing a hollow filter rod according to any one of claims 1 to 4, characterized in that: The mass of the plasticizer is 10-30% of the mass of the diacetate fiber bundle.

6. The method for preparing a hollow filter rod according to any one of claims 1 to 5, characterized in that: The plasticizer is kept warm before use, and the keeping temperature is 30-60°C.

7. The method for preparing a hollow filter rod according to any one of claims 1 to 6, characterized in that: The premixing is performed by a tow premixing device, and the tow premixing device comprises an upper bundling roller and a lower bundling roller.

8. The method for preparing a hollow filter rod according to claim 7, characterized in that: The opening angle of the upper bundling roller is 90°-150°; Preferably, the opening angle of the lower bundling roller is 30°-90°; Preferably, the opening angle of the lower bundling roller is smaller than the opening angle of the upper bundling roller.

9. The method for preparing a hollow filter rod according to claim 7 or 8, characterized in that: The width of the upper bundling roller is 15-30 cm; Preferably, the width of the lower bundling roller is 5-15 cm; Preferably, the width of the upper bundling roller is not less than the width of the lower bundling roller.

10. The method for preparing a hollow filter rod according to any one of claims 7 to 9, characterized in that: The upper bundling roller and the lower bundling roller are made of anti-adhesion material and are treated with anti-adhesion.

Images