High-basis-weight soft face tissue base paper and preparation method thereof

Abstract

The invention discloses high-basis-weight soft facial tissue base paper and a preparation method thereof. The high-basis-weight soft facial tissue base paper is prepared from the following raw materials: slurry and a surface sliding type softening agent which is added into a coating chemical medicine of a drying cylinder in a papermaking process, the pulp comprises the following components in parts by mass: 96-115 parts of softwood pulp, 885-904 parts of hardwood pulp, 4-6 parts of a wet strength agent and 2-4 parts of a de-bonding softening agent; and the addition amount of the surface-slippery softener is 1.5%-2.5% of the total mass of the sizing agent. Mixed pulp of softwood pulp and hardwood pulp serves as long fiber line pulp, hardwood pulp serves as short fiber line pulp, a de-bonding type softening agent and a wet strength agent are added, a surface sliding type softening agent is added into a drying cylinder coating chemical medicine, and base paper is prepared. According to the long fiber yarn, mixed pulp of coniferous wood and hardwood pulp is used, and fiber bridging net structures with different lengths are formed; hardwood pulp is used for short fiber lines, long fiber line pulp and short fiber line pulp are used in the rear-section pulp preparation stage, and the overall pure long fiber consumption is reduced while the bulk and the softness of the paper are improved.

Description

Technical Field

[0001] The invention relates to a facial tissue and a preparation method thereof, in particular to a high basis weight soft facial tissue base paper and a preparation method thereof. Background Art

[0002] In the prior art, high basis weight (20g / m 2 The main reason is that as the basis weight increases, the strength of the paper will increase linearly, the hand feel will be harder, and the surface smoothness will decrease, making it difficult to achieve both softness and smoothness. Therefore, the basis weight of facial tissue is generally not higher than 16.5g / m 2 .

[0003] For soft facial tissue, the base paper weight is usually 13-16g / m 2 Because the fiber content decreases after the basis weight of the base paper is reduced, the longitudinal and transverse tension of the paper itself will also be reduced. Compared with the high basis weight base paper, the feel will become softer. At the same time, the surface texture will make the fiber distribution more even due to the reduction of sizing flow during papermaking. When the upper drying cylinder is wrinkled, the wrinkles are delicate, making the paper surface smooth. However, the thickness of the base paper will also decrease synchronously after the basis weight is reduced. Today's market requires products that are both soft and smooth to the touch and thick.

[0004] The current low basis weight soft base paper can only be made by increasing the number of layers, such as 3 or 4 layers of 14g / m 2 However, when there are too many layers of facial tissue, the base paper rewinding section is prone to delamination or poor embossing between multiple layers, which brings a bad experience to consumers. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a high basis weight soft facial tissue base paper which can meet the requirements of smoothness, softness and bulkiness of the product and avoid the problems of delamination and poor embossing of multi-layer base paper;

[0006] The second object of the present invention is to provide a method for preparing the above-mentioned high basis weight soft facial tissue base paper.

[0007] Technical solution: The high basis weight soft facial tissue base paper of the present invention is prepared by raw materials including pulp and a surface-slip softener added to the drying cylinder coating chemical during papermaking; the components of the pulp include, by mass: 96-115 parts of coniferous wood pulp, 885-904 parts of hardwood pulp, 4-6 parts of wet strength agent, 2-4 parts of debonding softener, and 1.5-2.5 parts of surface-slip softener; the added amount of the surface-slip softener is 1.5‰-2.5‰ of the total mass of the pulp.

[0008] The debonding softener is selected from at least one of silane softeners and polyurethane softeners; more preferably, it is selected from at least one of LIANGSHI SF8866 and SOLEX TQ236.

[0009] Wherein, the wet strength agent is selected from at least one of polyamide epichlorohydrin resin and anionic polymer; more preferably, it is at least one of Fuhe P150 and Hengkang HK-5.

[0010] The method for preparing the above-mentioned high basis weight soft facial tissue base paper comprises the following steps:

[0011] (1) using a mixed pulp of coniferous wood pulp and hardwood pulp as long fiber pulp, using hardwood pulp as short fiber pulp, and mixing the long fiber pulp and the short fiber pulp to obtain a mixed pulp;

[0012] (2) adding a debonding softener to the mixed slurry and then adding a wet strength agent to obtain a slurry;

[0013] (3) The slurry is formed, squeezed for dehydration, and dried. During the drying process, a drying cylinder coating chemical is added, and a surface-slip softener is added to the drying cylinder coating chemical. The high-basis-weight soft facial tissue base paper is then obtained through rolling.

[0014] Wherein, in step (1), the mass proportions of coniferous wood pulp and broadleaf wood pulp in the long fiber pulp are in the range of 60%-65% and 35%-40% respectively.

[0015] Wherein, in step (1), the long fiber pulp accounts for 15%-18% of the mixed pulp, and the short fiber pulp accounts for 82%-85% of the mixed pulp.

[0016] Among them, in step (1), in the long fiber line: the coniferous wood pulp and the broadleaf wood pulp are sent to the long fiber dispersing machine for dispersing, and are stored in the long fiber unloading tower after the dispersing is completed, and are further stored in the long fiber post-beating tower after pulping; in the short fiber line: the broadleaf wood pulp is sent to the short fiber dispersing machine for dispersing, and are stored in the short fiber unloading tower after the dispersing is completed, and are further stored in the short fiber post-beating tower after being processed by the deflaker; and then the long fiber line pulp of the long fiber post-beating tower and the short fiber line pulp of the short fiber post-beating tower are mixed into the mixing pulp pool for mixing.

[0017] Among them, in step (2), a debonding softener is added to the mixed pulp, and the mixed pulp enters the front tank after passing through the modified pulp refiner, and a wet strength agent is added at the outlet of the front tank pump, and the mixed pulp is diluted and sent to the head box.

[0018] In step (3), the pulp obtained in step (2) is formed and pressed for dehydration by a paper machine blanket section, dried by a drying cylinder and a hot air hood, and a surface-slip softener is added to a peeling agent mixing tank for drying cylinder coating chemicals, wherein the drying cylinder coating chemicals, i.e., the drying cylinder coating chemicals and the peeling agent, are added to the peeling agent mixing tank at a flow rate of 180-220 ml / min for the drying cylinder coating chemicals and 20-30 ml / min for the peeling agent; and then the pulp is wound up by a winding cylinder to obtain a soft and smooth high basis weight soft facial tissue base paper; wherein a 5°-10° alloy knife is used during winding to ensure that the base paper surface is smooth and delicate while having a good bulk.

[0019] Among them, the amount of the added surface-slip softener is 1.5-2.5 parts; the surface-slip softener is selected from at least one of quaternary ammonium salt type and fatty acid ester type surface slippers; more preferably, it is at least one of Liangshi SF8630 and Hengkang HK-201.

[0020] Principle of the invention: The long fiber line pulp treatment uses a specific proportion of coniferous wood and hardwood mixed pulp and pulping. After the long and short fibers are mixed and pulped, due to the different lengths of coniferous wood and hardwood fibers, after the action of mechanical force, the long fibers are cut and split and the short fibers are split. The two fibers are combined by hydrogen bonds to form a certain bridging network structure. This structure makes the paper strength lower than that of pure long fiber pulping and the thickness higher. In addition, by adding a debonding softener in the mixed pulp tank, a part of the hydrogen bonds between the fibers are dissociated, thereby reducing the strength of the high basis weight facial tissue paper and making it soft. At the same time, a 5°-10° alloy knife is used and a surface-slip softener is added to the drying cylinder coating chemical to make the wrinkles of the paper uniform and delicate, thereby improving the smoothness of the paper surface.

[0021] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0022] (1) The present invention utilizes a modern toilet paper machine. The long-fiber line uses softwood and hardwood pulp in a mass ratio and then performs light pulping. Compared with the pure long-fiber pulping and pulping of the long-fiber line, the softwood and hardwood pulping in a certain ratio will form an optimal bridge network structure of fibers of different lengths after pulping, making the paper more fluffy and soft. The short-fiber line uses 100% hardwood pulp and deslurry. In the latter pulping stage, 15%-18% long-fiber line pulp + 82%-85% short-fiber line pulp is used, so that the overall pure long fiber dosage is controlled at 9.6%-11.5%, so as to improve the bulk and softness of the paper. (2) A 5° alloy knife is used in the initial rolling stage to take into account the texture of the base paper surface and the bulk of the base paper. In the winding stage, the wrinkling rate is increased to 29%-31%, so that the thickness of the base paper is increased and the tension is reduced. (3) Add a debonding softener to the pulp mixing tank and reduce the dosage to a stable level according to the reaction time gradient. Add a surface-smoothing softener to the drying cylinder coating mixing tank. The former releases the hydrogen bonds between the fibers to reduce the tension of the base paper and avoid excessive debonding, while the latter improves the smoothness of the base paper surface to obtain a 20 g / m 2 For high basis weight soft facial tissues with a weight of 200 g or more, only two layers are needed to meet product requirements, thus avoiding embossing delamination and defects. DETAILED DESCRIPTION

[0023] The present invention is described in further detail below.

[0024] Example 1

[0025] A high basis weight soft facial tissue base paper, the raw materials for its preparation include pulp and a surface slip softener added to the drying cylinder coating chemical during the papermaking process; the pulp components include by mass: 96 parts of coniferous wood, 904 parts of hardwood, 4 parts of wet strength agent, and 2 parts of debonding softener; the surface slip softener is Liangshi SF8630 surface slip softener, and its addition amount is 1.5‰ of the total mass of the pulp. The base paper preparation method includes the following steps:

[0026] (1) First, on the long fiber line, 640 parts of coniferous wood and 360 parts of hardwood pulp are sent to the long fiber dispersing machine. After the dispersing is completed, it is stored in the long fiber unloading tower, and then stored in the long fiber knocking tower after pulping; on the short fiber line, 1000 parts of hardwood pulp are sent to the short fiber dispersing machine for dispersing. After the dispersing is completed, it is stored in the short fiber unloading tower, and then stored in the short fiber knocking tower after being processed by the deflaker;

[0027] (2) The pulp from the long fiber tower after tapping and the pulp from the short fiber tower after tapping are mixed into a mixed pulp pool according to 15% long fiber line pulp + 85% short fiber line pulp;

[0028] (3) Add 2 parts of Liangshi SF8866 debonding softener to the mixed pulp tank, pass through the modified pulping machine and then enter the front tank of the machine, add 4 parts of Fuhe P150 wet strength agent at the outlet of the front tank pump, dilute the pulp with dilute white water through the SILO white water plate and send it to the head box, then pass through the forming pressing and dehydration of the paper machine mesh and blanket part, dry through the drying cylinder and hot air shield, add Liangshi SF8630 surface slip softener accounting for 1.5‰ of the total mass of the pulp to the stripping cylinder agent mixing tank for the drying cylinder coating, wherein the drying cylinder coating chemical is added to the stripping cylinder agent mixing tank at a flow rate of 180ml / min for the sticking cylinder agent and 20ml / min for the stripping agent; use a 5° alloy knife to ensure that the surface of the base paper is smooth and delicate while having a good bulk, and wind up the base paper with a winding cylinder to obtain a soft and smooth high basis weight soft tissue base paper.

[0029] Example 2

[0030] A high-basis-weight soft facial tissue base paper, the raw materials for its preparation include pulp and a surface-slip softener added to the drying cylinder coating chemical during the papermaking process; the components of the pulp include, by mass, 105 parts of coniferous wood, 895 parts of hardwood, 5 parts of wet strength agent, and 3 parts of debonding softener; the surface-slip softener is Liangshi SF8630 surface-slip softener, and its addition amount is 2‰ of the total mass of the pulp. The preparation method of the base paper includes the following steps:

[0031] (1) First, on the long fiber line, 640 parts of coniferous wood and 360 parts of hardwood pulp are sent to the long fiber dispersing machine. After the dispersing is completed, it is stored in the long fiber unloading tower, and then stored in the long fiber knocking tower after pulping; on the short fiber line, 1000 parts of hardwood pulp are sent to the short fiber dispersing machine for dispersing. After the dispersing is completed, it is stored in the short fiber unloading tower, and then stored in the short fiber knocking tower after being processed by the deflaker;

[0032] (2) The pulp from the long fiber tower after tapping and the pulp from the short fiber tower after tapping are mixed into a mixed pulp pool according to 16.5% long fiber line pulp + 83.5% short fiber line pulp;

[0033] (3) Add 3 parts of Liangshi SF8866 debonding softener to the mixed pulp tank, pass through the modified pulping machine and then enter the front tank of the machine, add 5 parts of Fuhe P150 wet strength agent at the outlet of the front tank pump, dilute the pulp with dilute white water through the SILO white water plate and send it to the head box, then pass through the forming pressing and dehydration of the paper machine mesh and blanket part, dry through the drying cylinder and hot air shield, add Liangshi SF8630 surface slip softener accounting for 2‰ of the total mass of the pulp to the stripping cylinder agent mixing tank for the drying cylinder coating, wherein the drying cylinder coating chemical is added to the stripping cylinder agent mixing tank at a flow rate of 220ml / min for the sticking cylinder agent and 30ml / min for the stripping agent; use a 5° alloy knife to ensure that the surface of the base paper is smooth and delicate while having a good bulk, and wind up the base paper with a winding cylinder to obtain a soft and smooth high basis weight soft tissue base paper.

[0034] Example 3

[0035] A high basis weight soft facial tissue base paper, the raw materials for its preparation include pulp and a surface slip softener added to the drying cylinder coating chemical during the papermaking process; the components of the pulp include by mass: 115 parts of coniferous wood, 885 parts of hardwood, 6 parts of wet strength agent, and 4 parts of debonding softener; the surface slip softener is Liangshi SF8630 surface slip softener, and its addition amount is 2.5‰ of the total mass of the pulp. The preparation method of the base paper includes the following steps:

[0036] (1) First, on the long fiber line, 640 parts of coniferous wood and 360 parts of hardwood pulp are sent to the long fiber dispersing machine. After the dispersing is completed, it is stored in the long fiber unloading tower, and then stored in the long fiber knocking tower after pulping; on the short fiber line, 1000 parts of hardwood pulp are sent to the short fiber dispersing machine for dispersing. After the dispersing is completed, it is stored in the short fiber unloading tower, and then stored in the short fiber knocking tower after being processed by the deflaker;

[0037] (2) The pulp from the long fiber tower after knocking and the pulp from the short fiber tower after knocking are mixed into a mixed pulp pool according to 18% long fiber line pulp + 82% short fiber line pulp;

[0038] (3) 4 parts of Liangshi SF8866 debonding softener are added to the mixed pulp tank, and then enter the front tank of the machine after passing through the modified pulping machine. 6 parts of Fuhe P150 wet strength agent are added at the outlet of the front tank pump. The pulp is diluted with white water through the SILO white water plate and sent to the head box. Then it is formed and pressed and dehydrated by the paper machine mesh and blanket part, and dried by the drying cylinder and hot air shield. Liangshi SF8630 surface slip softener accounting for 2.5‰ of the total mass of the pulp is added to the stripping cylinder agent mixing tank for the drying cylinder coating. Among them, the drying cylinder coating chemical is added to the stripping cylinder agent mixing tank at a flow rate of 180ml / min for the sticking cylinder agent and 20ml / min for the stripping agent. A 5° alloy knife is used to ensure that the surface of the base paper is smooth and delicate while having a good bulkiness. The winding cylinder is wound to obtain a soft and smooth high basis weight soft tissue base paper.

[0039] Comparative Example 1

[0040] Based on Example 1, different from Example 1, the long fiber line uses pure long fiber loose pulp and pulping. The pulp components include: 96 parts of coniferous wood, 904 parts of hardwood, 4 parts of wet strength agent, and 2 parts of debonding softener by weight. The preparation method of base paper includes the following steps:

[0041] (1) First, on the long fiber line, 1000 parts of softwood pulp are sent to the long fiber pulping machine for pulping. After pulping, the pulp is stored in the long fiber unloading tower, and then the pulp is refined and stored in the long fiber post-beating tower; on the short fiber line, 1000 parts of hardwood pulp are sent to the short fiber pulping machine for pulping. After pulping, the pulp is stored in the short fiber unloading tower, and then the pulp is processed by the deflaker and stored in the short fiber post-beating tower;

[0042] (2) The pulp from the long fiber tower after knocking and the pulp from the short fiber tower after knocking are mixed into a mixed pulp pool according to 9.6% long fiber line pulp + 80.4% short fiber line pulp;

[0043] (3) Add 2 parts of Liangshi SF8866 debonding softener to the mixed pulp tank, pass through the modified pulping machine and then enter the front tank of the machine, add 4 parts of Fuhe P150 wet strength agent at the outlet of the front tank pump, dilute the pulp with dilute white water through the SILO white water plate and send it to the head box, then pass through the forming pressing and dehydration of the paper machine mesh and blanket part, dry through the drying cylinder and hot air shield, add Liangshi SF8630 surface slip softener accounting for 1.5‰ of the total mass of the pulp to the stripping cylinder agent mixing tank for the drying cylinder coating, use a 5° alloy knife to ensure that the surface of the base paper is smooth and delicate while having good bulk, and take up the paper by the take-up cylinder to obtain high basis weight facial tissue base paper.

[0044] Comparative Example 2

[0045] Based on Example 1, the difference from Example 1 is that the pulp components include, by mass, 96 parts of coniferous wood, 904 parts of hardwood, 4 parts of wet strength agent, and 2 parts of debonding softener; the long fiber line uses a mixing ratio of 50% long fiber + 50% short fiber. The base paper preparation method comprises the following steps:

[0046] (1) First, on the long fiber line, 500 parts of coniferous wood + 500 parts of hardwood are sent to the long fiber pulping machine. After pulping, they are stored in the long fiber unloading tower, and then stored in the long fiber knocking tower after pulping; on the short fiber line, 1000 parts of hardwood pulp are sent to the short fiber pulping machine for pulping. After pulping, they are stored in the short fiber unloading tower, and then stored in the short fiber knocking tower after being processed by the deflaker;

[0047] (2) The pulp from the long fiber tower after knocking and the pulp from the short fiber tower after knocking are mixed into a mixed pulp pool according to 19% long fiber line pulp + 81% short fiber line pulp;

[0048] (3) Add 2 parts of Liangshi SF8866 debonding softener to the mixed pulp tank, pass through the modified pulping machine and then enter the front tank of the machine, add 4 parts of Fuhe P150 wet strength agent at the outlet of the front tank pump, dilute the pulp with dilute white water through the SILO white water plate and send it to the head box, then pass through the forming pressing and dehydration of the paper machine mesh and blanket part, dry through the drying cylinder and hot air shield, add Liangshi SF8630 surface slip softener accounting for 1.5‰ of the total mass of the pulp to the stripping cylinder agent mixing tank for the drying cylinder coating, use a 5° alloy knife to ensure that the surface of the base paper is smooth and delicate while having good bulk, and take up the paper by the take-up cylinder to obtain high basis weight facial tissue base paper.

[0049] Comparative Example 3

[0050] Based on Example 1, the difference from Example 1 is that the pulp components include, by mass, 96 parts of coniferous wood, 904 parts of hardwood, 4 parts of wet strength agent, and 1 part of debonding softener. The method for preparing base paper comprises the following steps:

[0051] (1) First, on the long fiber line, 640 parts of coniferous wood and 360 parts of hardwood are sent to the long fiber pulping machine. After pulping, they are stored in the long fiber unloading tower, and then stored in the long fiber knocking tower after pulping; on the short fiber line, 1000 parts of hardwood pulp are sent to the short fiber pulping machine for pulping. After pulping, they are stored in the short fiber unloading tower, and then stored in the short fiber knocking tower after being processed by the deflaker;

[0052] (2) The pulp from the long fiber tower after tapping and the pulp from the short fiber tower after tapping are mixed into a mixed pulp pool according to 15% long fiber line pulp + 85% short fiber line pulp;

[0053] (3) 1 part of Liangshi SF8866 debonding softener is added to the mixed pulp tank, and then enters the front tank after passing through the modified pulping machine. 4 parts of Fuhe P150 wet strength agent are added at the outlet of the front tank pump. The pulp is diluted with dilute white water through the SILO white water plate and sent to the head box. It is then formed and pressed for dehydration by the paper machine mesh and blanket section, and dried by the drying cylinder and hot air hood. Liangshi SF8630 surface slip softener accounting for 1.5‰ of the total mass of the pulp is added to the stripping cylinder agent mixing tank for the drying cylinder coating. A 5° alloy knife is used to ensure that the surface of the base paper is smooth and delicate while having a good bulkiness. The base paper is wound up by the winding cylinder to obtain a high basis weight facial tissue base paper.

[0054] The test results of the above embodiments and comparative examples are shown in Table 1 and Table 2 below.

[0055] Table 1

[0056]

[0057]

[0058] Table 2

[0059]

[0060] Note: The smaller the softness value, the softer the base paper is; the smaller the TS750 value, the smoother the base paper is.

Claims

1. A high basis weight soft facial tissue base paper, characterized in that: The raw materials for its preparation include pulp and a surface-slip softener added to the drying cylinder coating chemicals during papermaking; the components of the pulp include, by mass, 96-115 parts of coniferous wood pulp, 885-904 parts of hardwood pulp, 4-6 parts of wet strength agent, and 2-4 parts of debonding softener; the addition amount of the surface-slip softener is 1.5‰-2.5‰ of the total mass of the pulp.

2. The high basis weight soft facial tissue base paper according to claim 1, characterized in that: The debonding type softener is selected from at least one of a silane softener and a polyurethane softener.

3. The high basis weight soft facial tissue base paper according to claim 1, characterized in that: The wet strength agent is selected from at least one of polyamide epichlorohydrin resin and anionic polymer.

4. A method for preparing the high basis weight soft facial tissue base paper according to claim 1, characterized in that: The following steps are involved: (1) using a mixed pulp of coniferous wood pulp and hardwood wood pulp as long fiber line pulp, using hardwood wood pulp as short fiber line pulp, and mixing the long fiber line pulp and the short fiber line pulp to obtain a mixed pulp; (2) adding a debonding softener to the mixed slurry and then adding a wet strength agent to obtain a slurry; (3) The slurry is formed, squeezed for dehydration, and dried. During the drying process, a drying cylinder coating chemical is added, and a surface-slip softener is added to the drying cylinder coating chemical. The high-basis-weight soft facial tissue base paper is then obtained through rolling.

5. The method for preparing high basis weight soft facial tissue base paper according to claim 4, characterized in that: In step (1), the mass proportions of coniferous wood pulp and broadleaf wood pulp in the long fiber pulp are in the range of 60%-65% and 35%-40% respectively.

6. The method for preparing high basis weight soft facial tissue base paper according to claim 4, characterized in that: In step (1), the long fiber pulp accounts for 15%-18% of the mixed pulp, and the short fiber pulp accounts for 82%-85% of the mixed pulp.

7. The method for preparing high basis weight soft facial tissue base paper according to claim 4, characterized in that: In step (1), in the long fiber line: the coniferous wood pulp and the hardwood pulp are fed into the long fiber dispersing machine, and after the dispersing is completed, they are stored in the long fiber unloading tower, and then they are refined and stored in the long fiber post-beating tower; in the short fiber line: the hardwood pulp is fed into the short fiber dispersing machine for dispersing, and after the dispersing is completed, it is stored in the short fiber unloading tower, and then it is processed by the deflaker and stored in the short fiber post-beating tower; Then the long fiber line pulp from the long fiber knocking tower and the short fiber line pulp from the short fiber knocking tower are mixed into the mixing pulp pool for mixing.

8. The method for preparing high basis weight soft facial tissue base paper according to claim 4, characterized in that: In step (2), a debonding softener is added to the mixed pulp, and the mixed pulp enters the front tank after passing through the modified pulp refiner. A wet strength agent is added at the outlet of the front tank pump, and the mixed pulp is diluted and sent to the head box.

9. The method for preparing high basis weight soft facial tissue base paper according to claim 4, characterized in that: In step (3), the slurry obtained in step (2) is formed and pressed by the paper machine blanket section for dehydration, and then dried by a drying cylinder and a hot air hood. A drying cylinder coating chemical and a surface-slip softener accounting for 1.5‰ to 2.5‰ of the total mass of the slurry are added to the drying cylinder coating mixing tank, and then the slurry is wound up by a winding cylinder to obtain a soft and smooth high basis weight soft facial tissue base paper.

10. The method for preparing high basis weight soft facial tissue base paper according to claim 4, characterized in that: In step (3), the angle of the alloy knife used during coiling is 5°-10°.

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