High air permeability non-crinkling cellulose paper and its preparation method and application

Abstract

The application relates to a high-air-permeability non-creping cellulose paper and a preparation method and application thereof. The preparation method of the high-air-permeability non-creping cellulose paper comprises the following steps: S1. preparing pulp by mixing drying cylinder dried pulp, flash dried pulp, mercerized pulp, chemical fibers and water; S2. performing in-pulp sizing on the pulp in step S1, and then performing forming, dewatering and drying to obtain base paper; and S3. performing surface sizing on the base paper in step S2 and drying, so that the cellulose paper is obtained. The cellulose paper prepared by the preparation method has high thickness without needing transverse creping treatment, and has good air permeability, small suction resistance, good suction resistance stability and the like, and meets the requirements for preparing a fluted filter rod.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tobacco filter material, and more particularly to a high-air-permeability non-creased cellulose paper and a preparation method and application thereof. BACKGROUND

[0002] In recent years, the tobacco industry has continuously proposed new requirements for harm reduction and tar reduction of cigarettes, and the groove filter rod has the characteristics of high tar interception efficiency and novel appearance, so its application in harm reduction and tar reduction has rapidly expanded. Cellulose paper is a key component material of the groove filter rod, and plant fibers are generally selected as the main raw material. Compared with acetate fiber tows, cellulose paper has good air permeability and a large specific surface area, and a high surface hydrophilicity, and thus has higher adsorption performance and filtration efficiency.

[0003] The cellulose paper is compounded with the formed paper and the acetate fiber tow after groove pressing to form the groove filter rod. The groove of the groove filter rod is formed between the surfaces of the cellulose paper and the formed paper, and when the cigarette is smoked, part of the mainstream smoke passing through the filter rod penetrates the cellulose paper and flows out of the groove to the end of the cigarette. Due to the porous structure of the cellulose paper and the excellent adsorption performance of the plant fibers, the particulate matter in the mainstream smoke penetrating the cellulose paper is filtered and adsorbed by the fibers in the cellulose paper, and the tar reduction efficiency is high.

[0004] The main performance indicators of the cellulose paper include basis weight, air permeability, thickness and longitudinal tensile strength. The basis weight will significantly affect the pressure drop of the groove filter rod, and generally speaking, the higher the basis weight, the greater the pressure drop. The air permeability will affect the adsorption and filtration capacity of the groove filter rod for tar, and will also affect the pressure drop of the filter rod. Sufficient thickness ensures that the cellulose paper is not crushed during groove pressing, and also ensures the groove depth and shape to ensure that the smoke passing efficiency and appearance meet the design requirements. Good longitudinal tensile strength mainly ensures the running performance of the cellulose paper on the machine and prevents it from being crushed.

[0005] At present, the cellulose paper used in the industry is cellulose paper with irregular transverse wrinkles after transverse creping treatment. The transverse creping treatment is mainly to increase the thickness of the cellulose paper, and to assist in improving the transverse interception capacity of the groove filter rod for smoke components. However, the internal structure of the cellulose paper after transverse creping treatment is dense, and the three-dimensional thickness is uneven; the dense internal structure of the paper reduces the amount of mainstream smoke penetrating the cellulose paper and reduces the adsorption efficiency, and the uneven three-dimensional thickness causes the air permeability between the formed paper and the cellulose paper of the groove filter rod to be uneven, thereby causing the suction resistance of the groove filter rod to be unstable. When the mainstream smoke passes through the gap between the formed paper and the cellulose paper, the particulate matter in the smoke only undergoes inertial collision and diffusion deposition on the surface of the paper, and the interception and adsorption efficiency is low, and the cigarette smoke release and taste are not ideal. In addition, the cellulose paper used in the industry also has the problem of low air permeability, and its air permeability is usually less than 1000 cm3 / g.3 (min cm 2 ) below.

[0006] In order to solve the above-mentioned problems of the cellulose paper after transverse creping treatment, the industry attempts to develop a cellulose paper without transverse creping treatment, but such cellulose paper needs to be high in basis weight to meet the thickness requirement, but the high basis weight further reduces the air permeability of the cellulose paper; and the internal structure of such cellulose paper is dense, and the suction resistance is too large after being made into a grooved filter rod.

[0007] Therefore, it is necessary to solve the problems of the cellulose paper after transverse creping treatment, which has a large negative impact on the suction resistance, interception and adsorption of the grooved filter rod, or the cellulose paper without transverse creping treatment has a low air permeability due to a high basis weight and a large suction resistance due to a dense internal structure. SUMMARY

[0008] The primary object of the present application is to overcome the above-mentioned problems in the prior art and provide a preparation method of a high-air-permeability non-creped cellulose paper.

[0009] A further object of the present application is to provide a high-air-permeability non-creped cellulose paper.

[0010] A further object of the present application is to provide the use of the above-mentioned cellulose paper in the preparation of a grooved filter rod.

[0011] The above-mentioned objects of the present application are achieved by the following technical solutions:

[0012] A preparation method of a high-air-permeability non-creped cellulose paper, comprising the following steps:

[0013] S1. preparing a slurry from oven-dried pulp, flash-dried pulp, mercerized pulp, chemical fibers and water;

[0014] S2. performing in-situ sizing on the slurry of step S1, then performing forming, dewatering and drying to obtain a base paper;

[0015] S3. performing surface sizing on the base paper of step S2, and drying to obtain the cellulose paper;

[0016] The mass ratio of the oven-dried pulp, flash-dried pulp, mercerized pulp and chemical fibers in step S1 is (0.2-1):(1-3.2):(1.2-5):(0-0.2).

[0017] The preparation method of the present application adds a certain amount of mercerized pulp to the dryer dried pulp, which is the basic component of cellulose paper and provides basic strength to ensure the normal production of cellulose paper and continuous paper. The mercerized pulp has good air permeability, which can improve the air permeability of cellulose paper, reduce the resistance of cellulose paper, and make cellulose paper reach high thickness without the need for transverse creping treatment; however, the dispersibility of mercerized pulp is poor, and the strength of the paper is low, which can cause cellulose paper to be unable to be rolled into a groove filter rod, or the resistance of the groove filter rod after being made is unstable.

[0018] Further adding a certain amount of flash drying pulp is beneficial to the dispersion of mercerized pulp and cooperates with internal sizing to improve the strength of cellulose paper, so that cellulose paper can be rolled into a groove filter rod. In addition, since the addition of flash drying pulp is beneficial to the dispersion of mercerized pulp, the stability of the resistance of cellulose paper after being made into a groove filter rod can be ensured. The amount of flash drying pulp cannot be too much, otherwise the air permeability of cellulose paper will decrease.

[0019] That is, the preparation method of the present application uses dryer dried pulp, flash drying pulp, mercerized pulp and their amounts, and cooperates with internal sizing to make the cellulose paper prepared without the need for transverse creping treatment to reach high thickness, and has good air permeability, small resistance and good resistance stability, which meets the requirements for preparing a groove filter rod.

[0020] It should be understood that the dryer dried pulp of the present application refers to the pulp obtained after wet pulp is pressed and dewatered and then dried by a dryer, which is a conventional drying method for pulp. The flash drying pulp of the present application refers to the pulp obtained after wet pulp is treated by flash drying.

[0021] In the present application, the amount of dryer dried pulp in step S1 can be specifically 0.2, 0.5, 0.8 or 1 part by weight, the amount of flash drying pulp can be specifically 1, 1.5, 1.8, 2.0, 2.5, 2.8, 3.0 or 3.2 parts by weight, and the amount of mercerized pulp can be specifically 1.2, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 or 5 parts by weight.

[0022] Preferably, the ratio of the sum of the mass of the dryer dried pulp, the flash drying pulp, the mercerized pulp and the chemical fibers to the mass of water in step S1 is 1:(18-20).

[0023] Preferably, the dryer dried pulp in step S1 is at least one of hardwood pulp, softwood pulp, bagasse pulp, hemp pulp, straw pulp or bamboo pulp.

[0024] Preferably, the flash-dried pulp in step S1 has a fiber average length of 1.0-1.8 mm, an average width of 20.0-27.0 um, an average thickness of 0.10-0.18 mg / m, and a kink index of 20.0-30.0%.

[0025] More preferably, the flash-dried pulp in step S1 has a fiber average length of 1.5-1.7 mm, an average width of 23.5-24.5 um, an average thickness of 0.14-0.17 mg / m, and a kink index of 20.0-25.0%. Controlling the parameters in this range, the cellulose paper obtained has better air permeability, smaller suction resistance, and greater thickness at the same basis weight.

[0026] Preferably, the mercerized pulp in step S1 has a fiber average length of 2.5-2.8 mm, an average width of 27.0-30.0 um, an average thickness of 0.12-0.18 mg / m, and a kink index of 20%-35%.

[0027] Preferably, the chemical fiber in step S1 is at least one of viscose fiber, modal fiber, lyocell fiber, polyvinyl alcohol fiber, or polylactic acid fiber.

[0028] Preferably, the chemical fiber in step S1 has an average length of 4-6 mm and a linear density of 2.0-3.5 dtex.

[0029] Preferably, the process parameters for preparing the pulp in step S1 are: pulp concentration 4.0-6.0%, and pulping time 30-60 min.

[0030] Preferably, the pulp in step S1 has a beating degree of 12-40°SR.

[0031] Preferably, the mass ratio of the pulp sizing agent to the fiber in the pulp in step S2 is (1-8):(92-99).

[0032] More preferably, the pulp sizing agent is at least one of polyamide epoxy chloropropane resin, polyvinyl alcohol, starch, guar gum, polyethylene imine, or phenolic resin; and the starch includes but is not limited to at least one of dialdehyde starch and cationic starch.

[0033] Preferably, the mass ratio of the surface sizing agent to the base paper in step S3 is (0.2-4):100.

[0034] More preferably, the surface sizing agent is at least one of starch, polyvinyl alcohol, polyethylene glycol, acrylate, alkyl enone dimer, or carboxymethyl cellulose.

[0035] A high-air-permeability non-creped cellulose paper is prepared by the above preparation method.

[0036] Preferably, the basis weight of the cellulose paper is 80-90 g / m 2 .

[0037] The application of the above cellulose paper in preparing a fluted filter rod is also within the protection scope of the present application.

[0038] Preferably, the application of the cellulose paper as a forming paper in preparing a fluted filter rod.

[0039] Compared with the prior art, the present application has the following beneficial effects:

[0040] The cellulose paper prepared by the preparation method of the present application has high thickness without transverse creping treatment, and has good air permeability, small suction resistance, and good suction resistance stability, thus meeting the requirements for preparing a fluted filter rod. DETAILED DESCRIPTION

[0041] In order to more clearly and completely describe the technical solutions of the present application, the present application is further described in detail below through specific examples, and it should be understood that the specific examples described herein are only used to explain the present application and are not used to limit the present application, and various changes can be made within the scope of the present application.

[0042] Example 1

[0043] The present embodiment provides a preparation method of a high-air-permeability non-creped cellulose paper, comprising the following steps:

[0044] 1) Softwood pulp, flash-dry pulp (fiber average length of 1.5 mm, average width of 23.5 um, average thickness of 0.14 mg / m, and twist index of 24.1%), mercerized pulp (fiber average length of 2.6 mm, average width of 29.2 um, average thickness of 0.17 mg / m, and twist index of 32.6%), viscose fiber (linear density of 3.5 dtex, and average length of 6 mm), and water are uniformly mixed in a mass ratio of 1:1:5:0.1:134.9 to prepare pulp; the beating degree of the pulp is 13°SR;

[0045] 2) A 15wt% polyamide epichlorohydrin resin solution is added to the pulp obtained in step 1), and uniformly mixed, and then the paper machine is used to perform web forming, pressing dewatering, and drying to obtain a raw paper; wherein the mass ratio of the polyamide epichlorohydrin resin in the polyamide epichlorohydrin resin solution to the fiber in the pulp is 4:96;

[0046] 3) using an acrylate solution to perform surface sizing treatment on the base paper obtained in step 2), and drying, to obtain the cellulose paper. The acrylate used for surface sizing treatment accounts for 0.2 wt% of the cellulose paper.

[0047] Example 2

[0048] This example provides a method for preparing a high-air-permeability non-creped cellulose paper, which is basically the same as that of Example 1, except that:

[0049] In step 1), the softwood pulp is replaced by hemp pulp; the viscose fiber is replaced by polyvinyl alcohol fiber (linear density of 3.0 dtex, average length of 5 mm); the mass ratio of the softwood pulp, flash-dried pulp, mercerized pulp, polyvinyl alcohol fiber, and water is 1:3:2:0.1:115.9; the beating degree of the pulp is 15°SR;

[0050] 2) the polyamide epichlorohydrin resin solution is replaced by a dialdehyde starch solution; the mass ratio of dialdehyde starch in the dialdehyde starch solution to the fiber in the pulp is 8:92;

[0051] 3) the acrylate solution is replaced by a carboxymethyl cellulose solution to perform surface sizing treatment on the base paper obtained in step 2), and drying, to obtain the cellulose paper. The carboxymethyl cellulose used for surface sizing treatment accounts for 4 wt% of the cellulose paper.

[0052] Example 3

[0053] This example provides a method for preparing a high-air-permeability non-creped cellulose paper, which comprises the following steps:

[0054] 1) mixing the softwood pulp, flash-dried pulp (average fiber length of 1.5 mm, average width of 23.5 μm, average thickness of 0.14 mg / m, and twist index of 24.1%), mercerized pulp (average fiber length of 2.6 mm, average width of 29.2 μm, average thickness of 0.17 mg / m, and twist index of 32.6%), lyocell fiber (2.0 dtex, 4 mm), and water in a mass ratio of 0.2:3.2:1.2:0.2:91.2 to obtain a pulp, and the beating degree of the pulp is 12°SR;

[0055] 2) adding a polyamide epichlorohydrin resin solution with a concentration of 15 wt% to the pulp obtained in step 1) and mixing uniformly, and then performing the following steps on a paper machine: forming, pressing, dewatering, and drying, to obtain a base paper; the mass ratio of the polyamide epichlorohydrin resin in the solution to the fiber in the pulp is 4:96;

[0056] 3) surface sizing treatment of the base paper obtained in step 2) with a polyvinyl alcohol solution, drying, to obtain the cellulose paper. The polyvinyl alcohol used in the surface sizing treatment accounts for 0.2 wt% of the cellulose paper.

[0057] Example 4

[0058] This example provides a method for preparing a high-air-permeability non-crinkled cellulose paper, which is basically the same as that of Example 3, except that in step 1), the flash-dried pulp has an average fiber length of 1.2 mm, an average width of 22.5 um, an average thickness of 0.11 mg / m, and a twist index of 28.2%.

[0059] Example 5

[0060] This example provides a method for preparing a high-air-permeability non-crinkled cellulose paper, which is basically the same as that of Example 3, except that in step 1), the flash-dried pulp has an average fiber length of 1.7 mm, an average width of 24.5 um, an average thickness of 0.17 mg / m, and a twist index of 20.0%.

[0061] Example 6

[0062] This example provides a method for preparing a high-air-permeability non-crinkled cellulose paper, which is basically the same as that of Example 3, except that in step 1), the mercerized pulp has an average fiber length of 2.7 mm, an average width of 27.3 um, an average thickness of 0.13 mg / m, and a twist index of 20.9%.

[0063] Comparative Example 1

[0064] This comparative example provides a method for preparing a high-air-permeability non-crinkled cellulose paper, which is basically the same as that of Example 3, except that in step 1), no flash-dried pulp is added.

[0065] Comparative Example 2

[0066] This comparative example provides a method for preparing a cellulose paper, which is basically the same as that of Example 3, except that in step 1), the softwood pulp, flash-dried pulp, mercerized pulp, viscose fiber, and water are mixed in a mass ratio of 0.2:8:1.2:0.2:182.4.

[0067] Comparative Example 3

[0068] This comparative example provides a method for preparing a cellulose paper, which is basically the same as that of Example 3, except that in step 1), no mercerized pulp is added.

[0069] Comparative Example 4

[0070] The comparative example 4 provides a preparation method of cellulose paper, which is basically the same as that of the example 3, except that in the step 1), the softwood pulp, flash dry pulp, mercerized pulp, viscose fiber and water are uniformly mixed in a mass ratio of 0.2:3.2:8:0.2:220.4.

[0071] Comparative example 5

[0072] The comparative example 4 provides a preparation method of cellulose paper, which is basically the same as that of the example 3, except that in the step 1), the softwood pulp, flash dry pulp, mercerized pulp, viscose fiber and water are uniformly mixed in a mass ratio of 0.2:3.2:8:0.2:220.4.

[0073] Comparative example 6

[0074] The comparative example 4 provides a preparation method of cellulose paper, which is basically the same as that of the example 3, except that in the step 1), the softwood pulp, flash dry pulp, mercerized pulp, viscose fiber and water are uniformly mixed in a mass ratio of 0.2:3.2:8:0.2:220.4.

[0075] Performance test

[0076] The cellulose papers of each example and comparative example are tested:

[0077] (1) Cellulose paper sheet performance test

[0078] The basis weight of the paper is determined according to GB / T 451.2-2023, the air permeability of the paper is determined according to GB / T 23227-2018, the tensile strength of the paper is determined according to GB / T 12914-2018, and the thickness of the paper is determined according to GB / T 451.3-2002.

[0079] (2) Cellulose paper roll filter rod suction resistance test

[0080] Each cellulose paper is used to make a grooved filter rod on a filter rod forming machine with the same process parameters and the same type of filament. The grooved filter rod parameters are required to be: length 100 mm, circumference 24.05 mm, groove depth 0.4 mm, and groove number 16. The grooved filter rod is detected for suction resistance and suction resistance COV by a filter rod suction resistance tester according to GB / T 2238 Cigarettes and Filter Rods-Determination of Physical Properties-Part 5: Suction Resistance of Cigarettes and Pressure Drop of Filter Rods, and the data are shown in Table 1.

[0081] Table 1

[0082]

[0083]

[0084] From Table 1, it can be seen that:

[0085] Examples 1-6 ensure that the cellulose paper has high thickness (160 μm or more) at high basis weight, and the cellulose paper has air permeability of 1100 cm 3 / (min·cm 2 ) or more, suction resistance of 3000 Pa or less, and suction resistance COV of 3.0% or less, indicating that the cellulose paper of the present application can achieve high thickness without transverse creping treatment, and has good air permeability, small suction resistance, and high suction resistance stability.

[0086] Comparative Example 1 does not add flash-drying pulp, and the cellulose paper obtained has low strength and cannot be formed into a fluted filter rod. Comparative Example 2 adds too much flash-drying pulp, and the cellulose paper obtained has low air permeability, large suction resistance, and low thickness at the same basis weight. Comparative Example 3 does not add mercerizing pulp, and the cellulose paper obtained has low air permeability, low thickness at the same basis weight, and large suction resistance. Comparative Example 4 adds too much mercerizing pulp, and the suction resistance is unstable. Comparative Example 5 does not perform in-pulp sizing, and the cellulose paper obtained has low strength and cannot be formed into a fluted filter rod. Comparative Example 6 is a cellulose paper that is commonly subjected to transverse creping, and has low air permeability, large suction resistance, and poor suction resistance stability.

[0087] Obviously, the above examples of the present application are merely illustrative for clearly explaining the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those of ordinary skill in the art. It is not necessary or possible to exhaust all embodiments. Any modification, equivalent replacement, and improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A process for the production of high air permeability uncreped cellulose paper, characterized by, Comprising the following steps: S1. preparing a pulp from dryer dried pulp, flash dried pulp, mercerized pulp, chemical fiber and water; S2. performing internal sizing on the pulp prepared in step S1, then forming, dewatering and drying to obtain base paper; S3. performing surface sizing on the base paper prepared in step S2, and drying to obtain the cellulose paper; The mass ratio of the dryer dried pulp, flash dried pulp, mercerized pulp and chemical fiber in step S1 is (0.2-1):(1-3.2):(1.2-5):(0-0.2); The dryer dried pulp in step S1 is at least one of hardwood pulp, softwood pulp, bagasse pulp, hemp pulp, straw pulp or bamboo pulp; The flash dried pulp in step S1 has an average fiber length of 1.0-1.8mm, an average width of 20.0-27.0um, an average thickness of 0.10-0.18mg / m, and a kink index of 20.0-30.0%; The mercerized pulp in step S1 has an average fiber length of 2.5-2.8mm, an average width of 27.0-30.0um, an average thickness of 0.12-0.18mg / m, and a kink index of 20%-35%; The chemical fiber in step S1 has an average length of 4-6mm and a linear density of 2.0-3.5dtex; The beating degree of the pulp in step S1 is 12-40°SR; The mass ratio of the internal sizing agent to the pulp in step S2 is (1-8):(92-99); The mass ratio of the surface sizing agent to the base paper in step S3 is (0.2-4):100; The ratio of the sum of the mass of the dryer dried pulp, flash dried pulp, mercerized pulp and chemical fiber to the mass of water in step S1 is 1:(18-20); The chemical fiber in step S1 is at least one of viscose fiber, modal fiber, lyocell fiber, polyvinyl alcohol fiber or polylactic acid fiber; The process parameters for preparing the pulp in step S1 are: pulp concentration 4.0-6.0%, and pulping time 30-60min; The internal sizing agent is at least one of polyamide epoxy chloropropane resin, starch, polyethylene imine or phenolic resin; the starch is at least one of dialdehyde starch and cationic starch; The surface sizing agent is at least one of starch, polyvinyl alcohol, acrylate, alkyl enone dimer or carboxymethyl cellulose.

2. A high permeability uncreped cellulose paper characterized by, Prepared by the method of claim 1.

3. Use of the cellulose paper of claim 2 in the preparation of a grooved filter rod.

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