Method and structure for improving bulk and water absorption performance of kitchen paper

Abstract

The invention discloses a method and a structure for improving bulk and water absorption performance of kitchen paper. The method comprises the following steps: step 1, mixing and pulping high-yield pulp and softwood pulp; 2, wet kitchen paper raw paper is manufactured through a laboratory sheet making machine; and step 3, drying by using a vacuum dryer to obtain the raw paper of the kitchen paper in a dry state. The bulk and porosity of the raw paper of the kitchen paper are effectively improved, the water storage space of finished paper is increased, and the water absorption rate and water absorption capacity of the kitchen paper are increased; in addition, the water absorption performance, the softness and the skin-friendly degree of the kitchen paper are remarkably improved, so that the kitchen paper is more relaxed than traditional kitchen paper when a large amount of water is accumulated.

Description

Technical Field

[0001] The invention relates to the field of kitchen paper, and in particular to a method and a structure for improving the bulk and water absorption performance of kitchen paper. Background Art

[0002] Tissue paper is a general term for daily-use paper, especially for wiping paper used to take care of human life and go out. There are many types of daily-use paper, which can be divided into three categories according to the use environment: toilet paper, tissue paper (facial tissue, handkerchief paper, napkin paper) and wiping paper (kitchen paper, hand towel paper). The main properties of daily-use paper include liquid absorption performance, physical properties (tensile strength, bursting resistance and bulk, etc.) and softness. Liquid absorption performance is divided into liquid absorption capacity (the ability of daily-use paper to absorb and store liquid) and liquid absorption rate (the speed at which daily-use paper absorbs liquid). The good liquid absorption capacity of daily-use paper enables it to cope with complex liquid environments with high water and oil content. On the premise of ensuring high liquid absorption capacity, daily-use paper should also have a certain degree of physical strength performance to ensure that it will not be affected by damage during use. Of course, on the premise of meeting the basic performance of daily-use paper, some types of daily-use paper also need to contact human tissue. In order to be more comfortable during use, the softness performance of daily-use paper is also equally important. The above three main properties provide daily-use paper with characteristics and uses that are different from other types of paper. Kitchen paper is developed to cope with the complex oil and water environment in the kitchen and to keep the kitchen environment clean. Due to the complex oil and water environment in the kitchen, kitchen paper needs to have higher performance than other household papers. Kitchen paper is widely favored by consumers for its convenience, hygiene and other excellent usage experience, especially in economically developed areas. Kitchen paper has rapidly grown into one of the most important paper products in the field of household paper. However, traditional kitchen paper has obvious defects such as insufficient water absorption, slow water absorption rate, low wet strength after water absorption and easy to break, as well as low bulk and poor softness.

[0003] The water absorption performance of kitchen paper is mainly determined by the water absorption performance of the fibers that make up the kitchen paper (the water retention performance of the fiber cavity and the free hydroxyl content) and the pore structure produced by the fiber interweaving (its essence is the capillary effect). On the one hand, water is stored in the fiber cavity and combines with the free hydroxyl groups on the fiber surface, and on the other hand, it is absorbed by the pore structure in the paper. The oil absorption performance of kitchen paper mainly depends on the pore structure of the paper itself. The fibers are interwoven to form a pore structure, which gives the paper a large specific surface area, and after contacting oily substances, it can quickly absorb them.

[0004] Embossing was originally used as a decorative pattern in various plastic products, such as paper, fabric and leather. With the development of embossing technology in kitchen paper, kitchen paper embossing is now divided into two types: decorative embossing (DecoEmbossing) and micro embossing (Micro Embossing). Decorative embossing, as described, is mainly used on the surface layer of kitchen paper. It is usually a large pattern such as a beautiful pattern and a trademark. It is used to decorate kitchen paper and has little effect on the performance of kitchen paper. Micro embossing is mainly used on the bottom layer of kitchen paper. It is usually mainly dot embossing, small and dense, laid on the bottom layer and combined with the rest of the bottom paper, which not only allows the layers to be combined, but also increases the bulk, softness and interlayer pores of the kitchen paper, thereby improving the liquid absorption capacity (which is required for kitchen paper products).

[0005] With the development of papermaking technology, the process level of kitchen paper before embossing has gradually improved. These technologies have improved the basic performance of kitchen paper from different aspects, such as TAD (Through-Air Drying), which uses a non-pressing method to dry the paper and provides penetrating hot air in the longitudinal direction of the paper, which greatly increases the bulk of kitchen paper. As these processes continue to improve the performance of base paper, the development of embossing technology is particularly important. Embossing is equivalent to a secondary improvement in the various properties of kitchen paper. The increase in paper sheet thickness after embossing increases the bulk, and the looseness of the paper sheet structure increases the softness. The kitchen paper after multi-layer composite embossing forms interlayer gaps due to embossing. These gaps provide more water storage space for kitchen paper. Of course, embossing is also a double-edged sword. While making the paper sheet structure looser, it will reduce the strength of the base paper.

[0006] Embossing technology is also gradually developing. There are many ways of embossing. Different embossing methods can be used for products of different forms. At present, there is a molding method for the flow state of pulp, which is to make a pattern on the molding net. When the pulp is put on the net, it is formed along the shape of the net. This method reduces the loss of kitchen paper strength caused by embossing. Another method is to start with embossing technology, called Engraving Solutions' Express Technology, which is a combination of chemical and mechanical methods. The application of engraving solution also reduces the loss of physical strength of kitchen paper.

[0007] Traditional kitchen paper is generally made of a mixed pulp of coniferous and hardwood, with a pulping degree of 30°SR and a single-layer basis weight of about 20g / ㎡. It adopts double-layer composite embossing, and often uses embossing technology to design a variety of different embossing patterns to change the water absorption structure of the embossing points of the paper to improve the water absorption performance of the finished paper. However, the improvement of water absorption performance by simply changing the embossing pattern is very limited, and it is difficult to fundamentally change the water absorption performance of the paper. Summary of the invention

[0008] In view of this, the present invention provides a method and structure for improving the bulk and water absorption performance of kitchen paper.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0010] A method for improving the bulk and water absorption performance of kitchen paper comprises the following steps:

[0011] Step 1: Mix and beat high-yield pulp and coniferous wood pulp;

[0012] Step 2: Making wet kitchen paper base paper by a laboratory sheet making machine;

[0013] Step 3: Drying with a vacuum dryer to obtain dry kitchen paper base paper.

[0014] Preferably, in step 1, the mass percentage of high-yield pulp is 5% to 30%, and the mass percentage of coniferous wood pulp is 65% to 95%.

[0015] Preferably, in step 1, the beating degree is 25-30°SR, and the beating concentration is 0.3%-0.5%.

[0016] Preferably, in step 2, virgin wood pulp fibers are used in the papermaking process.

[0017] A structure for improving the bulk and water absorption performance of kitchen paper, comprising an embossed surface layer and an embossed bottom layer, wherein the embossed surface layer and the embossed bottom layer are both arranged in a horizontal direction, and the embossed surface layer is arranged above the embossed bottom layer;

[0018] The embossed surface layer comprises an embossed surface layer body and a plurality of first protruding units, the embossed surface layer body is arranged in the horizontal direction, a plurality of first protruding units are evenly spaced on the embossed surface layer in the horizontal direction, and a plurality of groups are evenly spaced in the longitudinal direction, the first protruding units are downwardly protruded from the lower bottom surface of the embossed surface layer body; a first water-retaining unit is formed between two adjacent first protruding units in the horizontal direction;

[0019] The embossed bottom layer includes an embossed bottom layer body and a plurality of second protrusion units. The embossed bottom layer body is arranged in a horizontal direction. A plurality of second protrusion units are evenly spaced on the embossed bottom layer body in the horizontal direction, and a plurality of groups are evenly spaced in the longitudinal direction. The second protrusion units are arranged to protrude upward from the upper surface of the embossed bottom layer body by pressing the second protrusion units. A second water-retaining unit is formed between two adjacent second protrusion units in the horizontal direction.

[0020] Preferably, the first water-retaining unit and the second water-retaining unit are symmetrically arranged in the longitudinal direction, the first protrusion unit and the second protrusion unit are symmetrically arranged in the longitudinal direction, and a plurality of the first protrusion units and the second protrusion units are arranged one by one up and down in the vertical direction, a plurality of the first water-retaining units and the second water-retaining units are arranged one by one up and down in the vertical direction, the lower bottom surface of the first protrusion unit and the upper surface of the second protrusion unit arranged opposite to each other are tightly connected, and the first protrusion unit and the second protrusion unit form a supporting structure with each other.

[0021] Preferably, the first water retention unit and the second water retention unit which are arranged opposite to each other are closely connected to form a water retention unit.

[0022] Preferably, the downward protrusion height of the first protrusion unit and the upward protrusion height of the second protrusion unit are equal, the downward protrusion height of the first protrusion unit is 0.3-0.8 mm, and the upward protrusion height of the second protrusion unit is 0.3-0.8 mm.

[0023] Preferably, the first protrusion unit and the second protrusion unit are in the shape of a cuboid, and the bottom surface of the first protrusion unit and the second protrusion unit is 2.0-7.0 mm long, 2.0-7.0 mm wide, and 0.3-0.8 mm high.

[0024] Preferably, the first protrusion unit and the second protrusion unit are laminated and embossed at a pressure of 0.15-0.65 MPa, and the embossed patterns of the embossed surface layer and the embossed bottom layer are the same, and the patterns of the embossed surface layer and the embossed bottom layer are arranged corresponding to each other.

[0025] Compared with the prior art, the present invention has achieved the following technical effects:

[0026] (1) The present invention uses high-yield pulp to replace part of the softwood pulp, and uses the high yield to stiffen the fiber. The obtained kitchen paper base paper has a significantly improved bulk and porosity compared with the traditional kitchen paper base paper; when the high-yield pulp accounts for 5%, the paper bulk is 2.71 cm 3 / g, the proportion of high-yield pulp increased to 30%, and the bulk thickness was 3.10cm 3 / g, an increase of 14.39%; compared with the paper without adding high-yield pulp, the bulk thickness increased by 3.44% to 18.32%;

[0027] (2) The kitchen paper obtained by the present invention has a first protruding unit and an upper surface of a second protruding unit that are arranged opposite to each other and are tightly connected, and the first protruding unit and the second protruding unit form a supporting structure with each other. The first water-retaining unit and the second water-retaining unit that are arranged opposite to each other are tightly connected to form water-retaining units. These water-retaining units will gradually absorb water and lock the absorbed water. The addition of high-yield pulp and the embossing process make the kitchen paper have good bulk and water absorption performance, and have good supporting structure and water absorption wet strength. The water absorption of paper with 5% high-yield pulp is 4.27g / g, the water absorption of paper with 5% high-yield pulp is 4.83g / g, and the water absorption of paper with 30% high-yield pulp is 6.48g / g, with an increase of 13.11% to 51.76%; the water absorption rate of paper without high-yield pulp is 36.84mm / 100s, the water absorption rate of paper with 5% high-yield pulp is 40.12mm / 100s, and the water absorption of paper with 30% high-yield pulp is 43.8mm / 100s, with an increase of 8.9% to 18.89%;

[0028] (3) The present invention improves the bulk and softness of the kitchen paper base paper and the internal porosity of the paper by adding high-yield pulp fibers, and can also significantly improve the water absorption performance, water absorption rate, softness and skin-friendliness of the kitchen paper, so that the kitchen paper can be more calm than traditional kitchen paper when facing large-area water accumulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is an overall structural diagram of a method and structure for improving the bulk and water absorption performance of kitchen paper according to the present invention;

[0030] Figure 2 A diagram showing the embossed surface structure of a method and structure for improving the bulk and water absorption performance of kitchen paper according to the present invention;

[0031] Figure 3 The present invention is a method for improving the bulk and water absorption performance of kitchen paper and an embossed bottom layer structure diagram of the structure.

[0032] In the figure, 1, embossed surface layer; 2, embossed bottom layer; 10, first protruding unit; 11, embossed surface layer body; 20, second protruding unit; 21, embossed bottom layer body; 100, first water-retaining unit; 200, second water-retaining unit. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The invention discloses a method for improving the bulk and water absorption performance of kitchen paper, comprising the following steps:

[0035] Step 1: Mix and beat 5% to 30% by mass of high-yield pulp and 65% to 95% by mass of coniferous wood pulp; the beating degree is 25 to 30° SR, and the beating concentration is 0.3% to 0.5%;

[0036] Step 2: using a laboratory sheeting machine to make wet kitchen paper base paper, using virgin wood pulp fiber in the papermaking process;

[0037] Step 3: Drying with a vacuum dryer to obtain dry kitchen paper base paper.

[0038] A structure for improving the bulk and water absorption performance of kitchen paper, comprising an embossed surface layer 1 and an embossed bottom layer 2, wherein the embossed surface layer 1 and the embossed bottom layer 2 are both arranged in a horizontal direction, and the embossed surface layer 1 is arranged above the embossed bottom layer 2;

[0039] The embossed surface layer 1 comprises an embossed surface layer body 11 and a plurality of first protruding units 10. The embossed surface layer body 11 is arranged in the horizontal direction. A plurality of first protruding units 10 are evenly spaced on the embossed surface layer 1 in the horizontal direction, and a plurality of groups are evenly spaced in the longitudinal direction. The first protruding units 10 are downwardly protruded from the lower bottom surface of the embossed surface layer body 11. A first water-retaining unit 100 is formed between two adjacent first protruding units 10 in the horizontal direction.

[0040] The embossed bottom layer 2 includes an embossed bottom layer body 21 and a plurality of second protrusion units 20. The embossed bottom layer body 21 is arranged in the horizontal direction. A plurality of second protrusion units 20 are evenly spaced on the embossed bottom layer body 21 in the horizontal direction, and a plurality of groups are evenly spaced in the longitudinal direction. The second protrusion units 20 are protruded upward from the upper surface of the embossed bottom layer body 21. A second water-retaining unit 200 is formed between two adjacent second protrusion units 20 in the horizontal direction.

[0041] The first water-retaining unit 100 and the second water-retaining unit 200 are symmetrically arranged in the longitudinal direction, the first protrusion unit 10 and the second protrusion unit 20 are symmetrically arranged in the longitudinal direction, and multiple first protrusion units 10 and second protrusion units 20 are arranged one by one up and down in the vertical direction. Multiple first water-retaining units 100 and second water-retaining units 200 are arranged one by one up and down in the vertical direction, and the lower bottom surface of the first protrusion unit 10 and the upper surface of the second protrusion unit 20 that are arranged opposite to each other are tightly connected, and the first protrusion unit 10 and the second protrusion unit 20 form a supporting structure with each other.

[0042] The first water retention unit 100 and the second water retention unit 200 which are arranged opposite to each other are closely connected to form a water retention unit.

[0043] The protrusion height of the first protrusion unit 10 protruding downward and the protrusion height of the second protrusion unit 20 protruding upward are equal. The protrusion height of the first protrusion unit 10 protruding downward is 0.3-0.8 mm, and the protrusion height of the second protrusion unit 20 protruding upward is 0.3-0.8 mm.

[0044] The first protrusion unit 10 and the second protrusion unit 20 are in a rectangular parallelepiped shape. The bottom surface of the first protrusion unit 10 and the second protrusion unit 20 is 2.0-7.0 mm long, 2.0-7.0 mm wide, and 0.3-0.8 mm high.

[0045] The first protrusion unit 10 and the second protrusion unit 20 are laminated and embossed by a pressure of 0.15-0.65 MPa, and the embossed patterns of the embossed surface layer 1 and the embossed bottom layer 2 are the same, and the patterns of the embossed surface layer 1 and the embossed bottom layer 2 are arranged corresponding to each other.

[0046] Embodiment 1:

[0047] A kitchen paper with high bulk and high water absorption performance is provided with an embossed surface layer 1 and an embossed bottom layer 2, and the base paper is made of a mixture of coniferous wood pulp and high-yield pulp, wherein the coniferous wood pulp accounts for 95% and the high-yield pulp accounts for 5%. The relevant tests of the present invention are shown in Table 1:

[0048] Table 1:

[0049]

[0050] It can be seen from Table 1 above that the embodiments are higher than the comparative examples and commercially available product examples in terms of both water absorption and water absorption rate. The water absorption of embodiment 1 is 11.84% higher than that of the commercially available product example. Compared with comparative examples 1, 2, and 3, the water absorption is increased by 3.62% to 13.76%; in terms of water absorption rate, embodiment 1 is 10.52% higher than that of the commercially available product example. Compared with comparative examples 1, 2, and 3, the water absorption rate is increased by 4.64% to 8.90%. The bulk of embodiment 1 is 6.69% higher than that of the commercially available product example, and the bulk is slightly increased by 1.12% to 3.44% compared with comparative examples 1, 2, and 3. It can be seen that the kitchen paper obtained in embodiment 1 of the present invention is superior to the commercially available product example and the comparative example in terms of both water absorption performance and bulk.

[0051] Embodiment 2:

[0052] A kitchen paper with high bulk and high water absorption performance is provided with an embossed surface layer 1 and an embossed bottom layer 2, and the base paper is made of a mixture of coniferous wood pulp and high-yield pulp, wherein the coniferous wood pulp accounts for 70% and the high-yield pulp accounts for 30%. The relevant tests of the present invention are shown in Table 2:

[0053] Table 2:

[0054]

[0055] As can be seen from Table 2 above, the water absorption of Example 2 is 39.80% higher than that of the commercial product, and the water absorption rate is 20.66% higher. Compared with Comparative Examples 4 and 5, the water absorption is increased by 10.97% and 6.16%, the water absorption rate is increased by 4.53% and 10.61%, and the bulk is increased by 9.54% and 13.14%. The high-yield pulp of Comparative Example 6 is higher than that of Example 2, but the water absorption and water absorption rate are not significantly improved, indicating that when the proportion of high-yield pulp reaches more than 30%, the improvement of water absorption performance is limited, and the tensile strength of paper also decreases significantly. Compared with Comparative Example 6, the tensile index of Example 2 decreases by 3.46%. It can be seen that the performance of the kitchen paper obtained in Example 2 of the present invention is better than that of the commercial product and Comparative Examples 4, 5, and 6.

[0056] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for improving the bulk and water absorption performance of kitchen paper, characterized in that: The following steps are involved: Step 1: Mix and beat high-yield pulp and coniferous wood pulp; Step 2: Making wet kitchen paper base paper by a laboratory sheet making machine; Step 3: Drying with a vacuum dryer to obtain dry kitchen paper base paper.

2. A method for improving the bulk and water absorption performance of kitchen paper according to claim 1, characterized in that: In the step 1, the mass percentage of the high-yield pulp is 5% to 30%, and the mass percentage of the coniferous wood pulp is 65% to 95%.

3. A method for improving the bulk and water absorption performance of kitchen paper according to claim 1, characterized in that: In the step 1, the beating degree is 25-30°SR, and the beating concentration is 0.3%-0.5%.

4. A method for improving the bulk and water absorption performance of kitchen paper according to claim 1, characterized in that: In the step 2, virgin wood pulp fibers are used in the papermaking process.

5. A structure for improving the bulk and water absorption performance of kitchen paper, characterized in that: It comprises an embossed surface layer (1) and an embossed bottom layer (2), wherein the embossed surface layer (1) and the embossed bottom layer (2) are both arranged in a horizontal direction, and the embossed surface layer (1) is arranged above the embossed bottom layer (2); The embossed surface layer (1) comprises an embossed surface layer body (11) and a plurality of first protruding units (10), wherein the embossed surface layer body (11) is arranged in a horizontal direction, a plurality of first protruding units (10) are evenly spaced on the embossed surface layer (1) in the horizontal direction, and a plurality of groups of first protruding units (10) are evenly spaced in the longitudinal direction, and the first protruding units (10) are protruded downward from the lower bottom surface of the embossed surface layer body (11); a first water-retaining unit (100) is formed between two adjacent first protruding units (10) in the horizontal direction; The embossed bottom layer (2) comprises an embossed bottom layer body (21) and a plurality of second protruding units (20); the embossed bottom layer body (21) is arranged in the horizontal direction; a plurality of second protruding units (20) are evenly spaced on the embossed bottom layer body (21) in the horizontal direction, and a plurality of groups are evenly spaced in the longitudinal direction; the second protruding units (20) are upwardly protruded from the upper surface of the embossed bottom layer body (21); and a second water-retaining unit (200) is formed between two adjacent second protruding units (20) in the horizontal direction.

6. A structure for improving the bulk and water absorption performance of kitchen paper according to claim 5, characterized in that: The first water-retaining unit (100) and the second water-retaining unit (200) are symmetrically arranged in the longitudinal direction, the first protrusion unit (10) and the second protrusion unit (20) are symmetrically arranged in the longitudinal direction, and a plurality of the first protrusion units (10) and the second protrusion units (20) are arranged one by one up and down in a vertical direction, a plurality of the first water-retaining units (100) and the second water-retaining units (200) are arranged one by one up and down in a vertical direction, the lower bottom surface of the first protrusion unit (10) and the upper surface of the second protrusion unit (20) arranged in a vertical direction are tightly connected, and the first protrusion unit (10) and the second protrusion unit (20) form a supporting structure with each other.

7. A structure for improving the bulk and water absorption performance of kitchen paper according to claim 5, characterized in that: The first water-retaining unit (100) and the second water-retaining unit (200) arranged opposite to each other are closely connected to form a water-retaining unit.

8. The structure for improving the bulk and water absorption performance of kitchen paper according to claim 5, characterized in that: The protrusion height of the first protrusion unit (10) protruding downward and the protrusion height of the second protrusion unit (20) protruding upward are equal, the protrusion height of the first protrusion unit (10) protruding downward is 0.3-0.8 mm, and the protrusion height of the second protrusion unit (20) protruding upward is 0.3-0.8 mm.

9. The structure for improving the bulk and water absorption performance of kitchen paper according to claim 5, characterized in that: The first protrusion unit (10) and the second protrusion unit (20) are in the shape of a rectangular parallelepiped, and the bottom surface of the first protrusion unit (10) and the second protrusion unit (20) is 2.0 to 7.0 mm long, 2.0 to 7.0 mm wide, and 0.3 to 0.8 mm high.

10. The structure for improving the bulk and water absorption performance of kitchen paper according to claim 5, characterized in that: The first protrusion unit (10) and the second protrusion unit (20) are laminated and embossed at a pressure of 0.15 to 0.65 MPa, and the embossed patterns of the embossed surface layer (1) and the embossed bottom layer (2) are the same, and the patterns of the embossed surface layer (1) and the embossed bottom layer (2) are arranged corresponding to each other.

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