Toilet paper and preparation method thereof

Abstract

The invention discloses toilet paper and a preparation method thereof, a fiber suspension contains nanocellulose, the absolute dry content of the nanocellulose in the fiber suspension is 0.5-2%, the absolute dry content of long fibers in the fiber suspension is 0-15%, and the absolute dry content of short fibers in the fiber suspension is 99.5-83%. The base weight of the toilet paper is 13.0 g / m < 2 >-20.0 g / m < 2 >, the longitudinal and transverse strength ratio is 1.4-2.2, the longitudinal strength is 200-500 gf / inch, and the transverse strength is 100-250 gf / inch. By means of the speed difference between a jet forming net and sizing, part of fibers are mainly arranged in the longitudinal direction, the other part of fibers are distributed between longitudinal fiber chains to form a fiber net, and the fibers are linked together through nanocellulose, so that the longitudinal strength of the paper is not remarkably changed, the use amount of long fibers or a dry strength agent or the pulping power is reduced, and the production cost is reduced. The paper production cost is reduced; the short fibers and the nanofibers in the transverse direction are combined and dispersed among the short fiber chains, so that the transverse strength is improved, the longitudinal-transverse strength ratio is reduced, and the trailing phenomenon during pull-apart is avoided; the nanocellulose is combined with the long and short fibers, so that the flexibility of the paper and the experience feeling of a user are improved.

Description

Technical Field

[0001] The invention relates to a papermaking process, in particular to toilet paper and a preparation method thereof. Background Art

[0002] There are many usage scenarios for household paper, such as at home or for consumers to carry with them when going out. In order to facilitate and serve people, more and more public places such as restaurants, hotels, shopping malls, airports, etc. provide toilet paper for people to use at any time. In order to meet the needs of usage scenarios, the appearance of household paper varies greatly. Taking toilet paper as an example, household toilet paper includes core roll paper, coreless roll paper, flat paper, pull-out type, etc. The weight of a single roll / single package is usually less than 200 grams, and the current mainstream number of layers is 2 to 4 layers; the toilet paper used in public places such as hotels and airports is generally core roll paper, and the weight of a single roll is usually more than 500 grams, and the number of layers is mainly 1 to 3 layers. When using, the staff installs the paper roll in the toilet paper box for consumers to extract and use. For cost considerations, most public places will provide 1 layer of toilet paper for free, and these products are not set with a point break line. After the user pulls the tail of the paper down to the appropriate length, tear the paper and use it. When the paper is torn, due to the low lateral strength of the paper, a long "tail" will remain on the paper roll (referred to as "tail"), which will increase paper scraps, affect the cleanliness, and affect the consumer experience.

[0003] This is mainly because the fibers used to produce toilet paper are composed of glucose monomers. The exposed hydroxyl groups on the fibers form hydrogen bonds with the hydroxyl groups on other nearby fibers, thus providing the paper with physical properties such as strength, tear resistance, and burst resistance. At the same time, there is also a certain frictional bonding force between the fibers. During the production process, the fiber mixed slurry is sprayed onto the forming net through the head box sizing to quickly dehydrate and form a wet paper web. Due to the speed difference between the forming net and the sizing, most of the fibers are mainly arranged longitudinally along the running direction of the forming net, which makes the longitudinal strength of the base paper much higher than the transverse strength. The longitudinal and transverse strength ratio of conventional toilet paper making technology ranges from 1.8 to 2.2. In order to avoid "tailing", it is necessary to improve the transverse strength of paper. The commonly used solutions in the industry are: increase the amount of long fibers. Compared with short fibers, long fibers can provide more hydroxyl groups and form more hydrogen bonds with other fibers, thereby providing higher strength for the paper; increase the amount of dry strength agent. The commonly used dry strength agent is polyacrylamide, whose molecular chains form a network cross-linking between fibers to enhance the stability of the fiber network. This network cross-linking helps to improve the bonding strength of the paper; increase the pulping power. Pulping is to use physical friction to make the fiber cell wall produce fluff, tear, split, and broom, etc., to release more hydroxyl groups, thereby increasing hydrogen bonding and improving paper strength. However, these methods increase the longitudinal strength of paper while increasing the transverse strength of paper, resulting in greater force required to tear the paper from the roll; the increase in longitudinal and transverse strength also leads to a decrease in the softness of the paper, affecting the consumer's experience; and at the same time, they also increase production costs. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to reduce the aspect ratio of paper while reducing production costs, and to provide a method for preparing toilet paper; another purpose of the present invention is to provide toilet paper prepared using the above-mentioned preparation method.

[0005] Technical solution: The method for preparing toilet paper of the present invention comprises the following steps:

[0006] (1) preparing long fiber slurry and short fiber slurry respectively, and mixing them to form a mixed slurry;

[0007] (2) the mixed slurry is further mixed and diluted to form a fiber suspension;

[0008] (3) The fiber suspension is subjected to sizing, forming, dehydration, pressing, drying, wrinkling and winding to produce toilet paper; in the step (1) or (2), nanocellulose is added to adjust the aspect ratio of the toilet paper, and in the step (2), the content of nanocellulose in the fiber suspension is 0.5-2%, the content of long fibers is 0-15%, and the content of short fibers is 99.5-83%.

[0009] Furthermore, the carboxyl content of the nanocellulose is between 0.3 and 1.5 mmol / g, and the degree of polymerization DP is between 300 and 900. Compared with long fibers or short fibers, nanocellulose has a larger specific surface area, and the surface is exposed with abundant hydroxyl groups, which can combine with long fibers or short fibers to form a large number of hydrogen bonds to enhance the binding force between fibers and thus enhance the strength of paper. When the carboxyl content of nanocellulose is too high and the degree of polymerization is too low, the highly polar carboxyl groups affect the dispersion of the fibers, and more long fibers need to be added to increase the dispersion of the fibers in the slurry, and a higher refining power is required to ensure the uniformity of the paper strength; when the carboxyl content of nanocellulose is too low and the degree of polymerization is too high, a small amount of nanocellulose cannot effectively bond with the long fibers and short fibers, and more long fibers still need to be added to maintain the network structure of the fibers in the slurry, and a higher refining power is required to ensure the uniformity of the paper strength.

[0010] Furthermore, the adding point of the nanocellulose is in the long fiber pulping tank or the short fiber pulping tank or the mixing tank or the front tank of the machine. The positions where the nanocellulose is added are different, and the mixing process is adjusted to ensure the uniformity of the mixing, which has little effect on the performance of the paper. For the convenience of production, it can be set at a reasonable adding point according to the process requirements.

[0011] Furthermore, in the fiber suspension in step (2), the content of nanocellulose is 0.5-1.5%, the content of long fibers is 0-10%, and the content of short fibers is 99.5-89.5%.

[0012] Furthermore, in the step (1), the mixing method of the long fiber pulp and the short fiber pulp includes: the long fiber line pulp board and the short fiber line pulp board are respectively infiltrated and dispersed to form the long fiber line pulp and the short fiber pulp, and then mixed; the long fiber pulp board and part of the short fiber pulp board are put into the long fiber dispersing tank for infiltration and dispersion to form the long fiber line pulp, and then mixed with the short fiber pulp formed by the remaining short fiber pulp board being infiltrated and dispersed separately; the long fiber pulp board and the short fiber pulp board are put into the long fiber dispersing tank for infiltration and dispersion to form the mixed pulp; the long fiber pulp board and the short fiber pulp board are put into the short fiber dispersing tank for infiltration and dispersion to form the mixed pulp. Since the amount of long fiber is small, the pulping power is reduced and the mixing method with the short fiber is less restricted, the process requirements are simplified and the production cost of paper is reduced.

[0013] Furthermore, in the step (2), the pulping power of the mixed pulp is 5-35 kwh / t. The use of long fibers is relatively large, and the pulping power is relatively large. The large pulping power causes the fibers to be over-fibered, resulting in excessive strength and poor softness, which reduces the softness of the paper and the user's experience. Therefore, reducing the use of long fibers can not only save manufacturing costs, but also reduce the pulping power, improve the softness of the paper and the user's experience.

[0014] Furthermore, the slurry concentration of the mixed slurry in step (2) is 2.5% to 4.5%. Appropriate slurry concentration can ensure paper quality, improve production efficiency and reduce manufacturing costs.

[0015] Furthermore, the fiber concentration of the fiber suspension in step (2) is 0.1% to 0.35% to ensure the basis weight, quality and economic benefits of the paper.

[0016] The present invention also provides toilet paper produced by the toilet paper preparation method, wherein the basis weight of the toilet paper is 13.0 g / ㎡ to 20.0 g / ㎡, and the longitudinal and transverse strength ratio is 1.4 to 2.2.

[0017] Furthermore, the longitudinal to transverse strength ratio of the toilet paper is between 1.6 and 2.0, the longitudinal strength of the toilet paper is between 200 and 500 gf / 25 mm, and the transverse strength of the toilet paper is between 100 and 250 gf / 25 mm.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: 1. By utilizing the speed difference between the injection molding network and the sizing, some fibers are mainly arranged longitudinally, and the other part of the fibers are distributed between the longitudinal fiber chains to form a fiber network. The fibers are also linked together by nanocellulose, so that the longitudinal strength of the paper remains unchanged, the amount of long fibers or dry strength agents used or the pulping power is reduced, and the paper production cost is reduced; 2. The transverse fibers are combined with nanofibers and dispersed between the fiber chains, which reduces the longitudinal and transverse strength ratio without affecting the longitudinal strength of the paper, and avoids the occurrence of tailing when breaking; 3. Nanocellulose is combined with fibers in the longitudinal and transverse directions, which increases the strength of the paper while improving the flexibility of the paper, thereby improving the user experience; 4. The basis weight of the toilet paper prepared by this method is 13.0g / ㎡~20.0g / ㎡, the longitudinal and transverse strength ratio is 1.4~2.2, the longitudinal strength is 200~500gf / 25mm, and the transverse strength is 100~250gf / 25mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0021] like Figure 1 A method for preparing toilet paper is shown, comprising the following steps:

[0022] (1) preparing long fiber slurry and short fiber slurry respectively, and mixing them to form a mixed slurry;

[0023] (2) the mixed slurry is further mixed and diluted to form a fiber suspension;

[0024] (3) The fiber suspension is sizing, forming, dehydrating, pressing, drying, wrinkling and winding to produce toilet paper.

[0025] In the preparation process of toilet paper, the addition ratio of long fiber pulp, short fiber pulp and nanocellulose and the mixing method thereof are detailed in Examples 1 to 5 and Comparative Examples 1 to 2.

[0026] Example 1

[0027] (1) 150 parts of long fiber pulp and 850 parts of short fiber pulp are sent to the long fiber dispersing machine, and after being wetted and dispersed, they are stored in the long fiber unloading tower, and then transferred to the long fiber knocking tower to form long fiber line pulp;

[0028] Another 989 parts of short fiber pulp and 11 parts of nanocellulose fibers were sent to the short fiber dispersing machine, and after being wetted and dispersed, they were stored in the short fiber unloading tower, and after being processed by the deflaker, they were stored in the short fiber knocking tower to form short fiber line pulp;

[0029] (2) 10% of the slurry from the long fiber tower after knocking and 90% of the slurry from the short fiber tower after knocking are mixed into a mixing tank to form a mixed slurry, and the mixed slurry is refined at a refining power of 10 kwh / t;

[0030] The mixed slurry enters the front tank of the machine for further mixing, and the slurry concentration of the mixed slurry is 3.12%;

[0031] The mixed slurry in the front tank of the machine is further diluted by the dilution tower and then enters the head box to form a fiber suspension with a concentration of 0.21%;

[0032] (3) The fiber suspension is sequentially sizing, forming, dehydrating, pressing, drying, wrinkling and winding to obtain toilet paper base paper.

[0033] The carboxyl content of the nanocellulose fibers is 0.73 mmol / g, and the average degree of polymerization DP is 471; the absolute dry content of the nanocellulose fibers is 1%, the absolute dry content of the long fibers is 1.5%, and the absolute dry content of the short fibers is 97.5%.

[0034] Example 2

[0035] (1) 980 portions of short fiber pulp are sent to a short fiber dispersing machine, and after being wetted and dispersed, they are stored in a short fiber unloading tower, and after being processed by a deflaker, they are stored in a short fiber knocking tower to form a short fiber line pulp;

[0036] (2) The pulp from the short fiber knocking tower enters the mixing tank, and 20 parts of nanocellulose fibers are added to form a mixed pulp. The refining power is 5 kwh / t;

[0037] The mixed slurry enters the front tank of the machine for further mixing, and the slurry concentration of the mixed slurry is 3.09%;

[0038] The mixed slurry in the front tank of the machine is further diluted by the dilution tower and then enters the head box to form a fiber suspension with a concentration of 0.23%;

[0039] (3) The fiber suspension is sequentially sizing, forming, dehydrating, pressing, drying, wrinkling and winding to obtain toilet paper base paper.

[0040] The carboxyl content of the nanocellulose fibers is 0.73 mmol / g, and the average degree of polymerization DP is 471; the absolute dry weight content of the nanocellulose fibers is 2%, and the absolute dry weight content of the short fibers is 98%.

[0041] Example 3

[0042] (1) 750 parts of long fiber pulp and 250 parts of short fiber pulp are sent to the long fiber dispersing machine, and after being wetted and dispersed, they are stored in the long fiber unloading tower, and then transferred to the long fiber knocking tower to form long fiber line pulp;

[0043] Another 994 parts of short fiber pulp and 6 parts of nanocellulose fibers were sent to the short fiber dispersing machine, and after being wetted and dispersed, they were stored in the short fiber unloading tower, and after being processed by the deflaker, they were stored in the short fiber knocking tower to form short fiber line pulp;

[0044] (2) 20% of the slurry from the long fiber tower after tapping and 80% of the slurry from the short fiber tower after tapping are mixed into a mixing tank to form a mixed slurry, and the mixed slurry is refined at a refining power of 15 kwh / t;

[0045] The mixed slurry enters the front tank of the machine for further mixing, and the slurry concentration of the mixed slurry is 2.99%;

[0046] The mixed pulp in the front tank of the machine is further diluted by the dilution tower and then enters the headbox to form a fiber suspension with a concentration of 0.20%;

[0047] (3) The fiber suspension is sequentially sizing, forming, dehydrating, pressing, drying, wrinkling and winding to obtain toilet paper base paper.

[0048] The carboxyl content of the nanocellulose fibers is 0.59 mmol / g, the average degree of polymerization DP is 436, the absolute dry content of the nanocellulose fibers is 0.5%, the absolute dry content of the long fibers is 15%, and the absolute dry content of the short fibers is 84.5%.

[0049] Example 4

[0050] (1) 750 parts of long fiber pulp and 250 parts of short fiber pulp are sent to the long fiber dispersing machine, and after being wetted and dispersed, they are stored in the long fiber unloading tower, and then transferred to the long fiber knocking tower to form long fiber line pulp;

[0051] Another 1,000 portions of short fiber pulp are sent to the short fiber dispersing machine, and after being soaked and dispersed, they are stored in the short fiber unloading tower, and after being processed by the deflaker, they are stored in the short fiber knocking tower to form short fiber line pulp;

[0052] (2) 20% of the pulp from the long fiber tower after tapping and 79.5% of the pulp from the short fiber tower after tapping are mixed into a mixing tank to form a mixed pulp, and the mixed pulp is refined at a refining power of 35 kwh / t;

[0053] The mixed slurry enters the front tank of the machine and is further mixed by adding 0.5% nanocellulose. The slurry concentration of the mixed slurry is 2.99%;

[0054] The mixed slurry in the front tank of the machine is further diluted by the dilution tower and then enters the head box to form a fiber suspension with a concentration of 0.19%;

[0055] (3) The fiber suspension is sequentially sizing, forming, dehydrating, pressing, drying, wrinkling and winding to obtain toilet paper base paper.

[0056] The carboxyl content of the nanocellulose fibers is 0.59 mmol / g, and the average degree of polymerization DP is 436; the absolute dry content of the nanocellulose fibers is 0.5%, the absolute dry content of the long fibers is 15%, and the absolute dry content of the short fibers is 84.5%.

[0057] Example 5

[0058] (1) 400 parts of long fiber pulp and 600 parts of short fiber pulp are sent to the long fiber dispersing machine, and after being wetted and dispersed, they are stored in the long fiber unloading tower, and then transferred to the long fiber knocking tower to form long fiber line pulp. The pulping power is 10 kwh / t;

[0059] Another 980 parts of short fiber pulp and 20 parts of nanocellulose fibers are sent to the short fiber dispersing machine, and after being wetted and dispersed, they are stored in the short fiber unloading tower, and after being processed by the deflaker, they are stored in the short fiber knocking tower to form short fiber line pulp;

[0060] (2) 25% of the slurry from the long fiber tower after tapping and 75% of the slurry from the short fiber tower after tapping are mixed into a mixing tank to form a mixed slurry;

[0061] The mixed slurry enters the front tank of the machine for further mixing, and the slurry concentration of the mixed slurry is 3.16%;

[0062] The mixed slurry in the front tank of the machine is further diluted by the dilution tower and then enters the head box to form a fiber suspension with a concentration of 0.21%;

[0063] (3) The fiber suspension is sequentially sizing, forming, dehydrating, pressing, drying, wrinkling and winding to obtain toilet paper base paper.

[0064] The carboxyl content of the nanocellulose fibers is 1.28 mmol / g, and the average degree of polymerization DP is 780; the absolute dry content of the nanocellulose fibers is 1.5%, the absolute dry content of the long fibers is 10%, and the absolute dry content of the short fibers is 88.5%.

[0065] Comparative Example 1

[0066] Different from Examples 1 to 5, in Comparative Example 1, no nanocellulose was added.

[0067] (1) 1000 portions of long fiber pulp are sent to a long fiber dispersing machine, and after being wetted and dispersed, they are stored in a long fiber unloading tower, and then transferred to a long fiber knocking tower to form a long fiber line pulp. The pulping power is 20 kwh / t;

[0068] Another 1,000 portions of short fiber pulp are sent to the short fiber dispersing machine, and after being soaked and dispersed, they are stored in the short fiber unloading tower, and after being processed by the deflaker, they are stored in the short fiber knocking tower to form short fiber line pulp;

[0069] (2) 17% of the slurry from the long fiber tower after knocking and 83% of the slurry from the short fiber tower after knocking are mixed into a mixing tank to form a mixed slurry, and the mixed slurry is refined at a refining power of 20 kwh / t;

[0070] The mixed slurry enters the front tank of the machine for further mixing, and the slurry concentration of the mixed slurry is 3.15%;

[0071] The mixed slurry in the front tank of the machine is further diluted by the dilution tower and then enters the head box to form a fiber suspension with a concentration of 0.22%;

[0072] (3) The fiber suspension is sequentially sizing, forming, dehydrating, pressing, drying, wrinkling and winding to obtain toilet paper base paper.

[0073] The dry content of long fibers is 17%, and that of short fibers is 83%.

[0074] Comparative Example 2

[0075] Different from Comparative Example 1, only short fiber pulp was used to make the mixed slurry.

[0076] (1) 1000 portions of short fiber pulp are sent to a short fiber dispersing machine, and after being wetted and dispersed, they are stored in a short fiber unloading tower, and after being processed by a deflaker, they are stored in a short fiber knocking tower to form a short fiber line pulp;

[0077] (2) 100% of the pulp from the short fiber knocking tower is taken into the mixing tank for mixing to form a mixed pulp and the mixed pulp is refined at a refining power of 5 kwh / t;

[0078] The mixed slurry enters the front tank of the machine for further mixing, and the slurry concentration of the mixed slurry is 3.13%;

[0079] The mixed slurry in the front tank of the machine is further diluted by the dilution tower and then enters the head box to form a fiber suspension with a concentration of 0.2%;

[0080] (3) The fiber suspension is sequentially sizing, forming, dehydrating, pressing, drying, wrinkling and winding to obtain toilet paper base paper.

[0081] The dry content of the staple fibers is 100%.

[0082] The basis weight, longitudinal strength, transverse strength and longitudinal and transverse strength ratio of the toilet paper base papers prepared in Examples 1 to 5 and Comparative Examples 1 to 2 were tested, as shown in Table 1 for details.

[0083] Table 1 Test results of toilet paper properties prepared under different conditions

[0084]

[0085] In comparison with Examples 1 to 5, the carboxyl content and degree of polymerization of nanocellulose are too high or too low, and the aspect ratio is relatively large: when the carboxyl content of nanocellulose is too high and the degree of polymerization is too high, the highly polar carboxyl groups make its dispersion performance poor, and more long fibers need to be added to increase the dispersion of the internal fibers of the slurry, and a higher refining power is required to ensure the uniformity of the paper strength, and the aspect ratio of the paper cannot be effectively improved and the production cost cannot be reduced; when the carboxyl content of nanocellulose is too low and the degree of polymerization is low, a small amount of nanocellulose cannot be effectively bonded with the long fibers and short fibers, and more long fibers still need to be added to maintain the network structure of the fibers of the slurry, and a higher refining power is required to ensure the uniformity of the paper strength, and the aspect ratio of the paper cannot be effectively improved and the production cost cannot be reduced. When the carboxyl content of nanocellulose is 0.73 and the degree of polymerization is 471, adding a small amount of nanocellulose can greatly reduce the amount of long fibers used. At this time, the difference between the longitudinal strength and the transverse strength of the paper becomes smaller, and the longitudinal and transverse strength ratio is between 1.4 and 1.6. The reduction in the longitudinal and transverse strength ratio effectively avoids the "tailing" problem when tearing, and greatly reduces the cost of paper production.

[0086] Comparing Examples 1-2 and Comparative Examples 1-2, when the amount of long fibers used in Examples 1-2 is greatly reduced, the basis weight, longitudinal strength and transverse strength of the paper can meet the quality requirements of paper products. Compared with Comparative Examples 1-2, after the amount of long fibers is greatly reduced, the longitudinal strength and transverse strength of the paper are greatly reduced, resulting in a decrease in the strength of the toilet paper; at the same time, the longitudinal and transverse strength ratio is maintained at 2.1-2.2, which cannot effectively improve the "tailing" problem caused by the paper when it is torn. However, in Examples 1-2, the amount of short fibers used is controlled at a relatively high ratio, the amount of long fibers used is gradually reduced, and the amount of nanocellulose used is increased. The pulping power gradually decreases, the longitudinal strength of the paper is slightly reduced by 3%, the transverse strength is increased by 9%, and the longitudinal and transverse strength ratio is reduced by 12.5%. Nanocellulose has a larger specific surface area than long fibers or short fibers, and the surface is exposed with abundant carboxyl groups to form a large number of hydrogen bonds with long fibers or short fibers to enhance the bonding force between each other and enhance the strength of the paper, but this bonding force is less than the breaking strength of the long fibers, so it is relatively easy to tear the paper. In Examples 1 to 2, the amount of long fibers used is greatly reduced. Due to the presence of nanocellulose, there is a speed difference between the fiber mixed slurry injection molding network and the sizing. Some short fibers are arranged regularly in the longitudinal direction. The short fibers are linked together in the longitudinal direction through nanocellulose. The other part of the short fibers are distributed between the short fiber chains in the longitudinal direction to form a fiber web. By using the speed difference, the short fibers can be arranged more regularly than the long fibers. At the same time, the strength of the short fiber chains in the longitudinal direction is slightly lower than that of the long fibers, and the linked short fibers are more flexible. The force required to tear the paper is reduced without affecting the longitudinal strength of the paper, and the flexibility of the paper is improved. The short fibers in the transverse direction are combined with nanofibers and distributed between the short fiber chains. On the basis of meeting the flexibility of the paper, the transverse strength is improved, and the longitudinal and transverse strength ratio is reduced to further avoid the "tailing" problem caused by the tearing of the paper. In addition, the smaller pulping power avoids the excessive fiber splitting and brooming, which leads to the roughness of the paper surface and the deterioration of softness, further improving the softness of the paper and the user's experience.

Claims

1. A method for preparing toilet paper, comprising the following steps: (1) preparing long fiber slurry and short fiber slurry respectively, and mixing them to form a mixed slurry; (2) the mixed slurry is further refined and diluted to form a fiber suspension; (3) The fiber suspension is subjected to sizing, forming, dehydration, pressing, drying, wrinkling and winding to produce toilet paper; characterized in that: The step (1) or (2) described herein adds nanocellulose for adjusting the aspect ratio of toilet paper. In the step (2), the content of nanocellulose in the fiber suspension is 0.5-2%, the content of long fibers is 0-15%, and the content of short fibers is 99.5-83%.

2. The method for preparing toilet paper according to claim 1, characterized in that: The carboxyl content of the nanocellulose is 0.3-1.5 mmol / g.

3. The method for preparing toilet paper according to claim 1, characterized in that: The degree of polymerization DP of the nanocellulose is between 300 and 900.

4. The method for preparing toilet paper according to claim 1, characterized in that: The adding point of the nanocellulose is in the long fiber pulping tank or the short fiber pulping tank or the mixing tank or the front tank of the machine.

5. The method for preparing toilet paper according to claim 1 or 4, characterized in that: In the step (2), the content of nanocellulose in the fiber suspension is 0.5-1.5%, the content of long fibers is 0-10%, and the content of short fibers is 99.5-89.5%.

6. The method for preparing toilet paper according to claim 1, characterized in that: The mixing method of the long fiber slurry and the short fiber slurry in the step (1) includes: the long fiber line pulp board and the short fiber line pulp board are respectively infiltrated and dispersed to form long fiber slurry and short fiber slurry, and then mixed; the long fiber pulp board and part of the short fiber pulp board are put into the long fiber dispersing tank for infiltration and dispersion to form long fiber line slurry, and then mixed with the short fiber slurry formed by the remaining short fiber pulp board being infiltrated and dispersed separately; the long fiber pulp board and the short fiber pulp board are put into the long fiber dispersing tank for infiltration and dispersion to form a mixed slurry; the long fiber pulp board and the short fiber pulp board are put into the short fiber dispersing tank for infiltration and dispersion to form a mixed slurry.

7. The method for preparing toilet paper according to claim 1, characterized in that: The refining power of the mixed slurry in the step (2) is 5 to 35 kwh / t.

8. The method for preparing toilet paper according to claim 1, characterized in that: The slurry concentration of the mixed slurry in step (2) is 2.5% to 4.5%.

9. The method for preparing toilet paper according to claim 1, characterized in that: The fiber concentration of the fiber suspension in step (2) is 0.1% to 0.35%.

10. A toilet paper produced using the method for preparing toilet paper according to any one of claims 1 to 9.

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