Paper cup base paper and its production process

Abstract

The application provides a paper cup base paper and a production process thereof. The production process comprises the following steps: preparing a fiber slurry; mixing the fiber slurry with modified silicate glass powder to prepare a mixed slurry; performing web forming, press dewatering and drying on the mixed slurry to obtain the paper cup base paper; wherein the modified silicate glass powder is prepared through the following steps: S1, uniformly mixing and grinding titanium oxide, sodium oxide, barium carbonate, calcium carbonate, boron oxide and silicon oxide to obtain a glass matrix; S2, heating and melting the glass matrix at a temperature of 1400 DEG C to 1600 DEG C to obtain a glass liquid; S3, water quenching and grinding the glass liquid to obtain glass powder; and S4, feeding the glass powder into a fluidized bed and spraying a polymer modifier into the fluidized bed to obtain the modified silicate glass powder. The paper cup base paper has good mechanical properties.

Description

Technical Field

[0001] This invention relates to the technical field of packaging materials, and more specifically, to a paper cup base paper and its production process. Background Technology

[0002] Paper cup base paper is made from pulp through a series of processing steps, specifically designed for manufacturing paper cups, paper plates, and other paper products. It typically requires good stiffness and whiteness. In existing technologies, the stiffness and whiteness of paper cup base paper are usually improved by adding inorganic fillers during the pulping process. Silica, alumina, titanium dioxide, and glass powder are all viable inorganic fillers.

[0003] Silicate glass powder is prepared from silicate minerals and / or inorganic salts through high-temperature melting, cooling, and grinding processes. It possesses characteristics such as high hardness, high abrasion resistance, high chemical stability, and low thermal conductivity. In papermaking, the high hardness and abrasion resistance of silicate glass powder help improve the strength and durability of paper, making paper cups and other paper products more robust and durable. The tiny particles of silicate glass powder can also fill the gaps between paper fibers, making the paper surface smoother and thus improving its gloss and whiteness, resulting in a more aesthetically pleasing appearance for paper cups. Furthermore, silicate glass powder has good chemical stability and is not prone to reacting with other substances, thereby improving the paper's barrier properties against moisture, oils, and other substances, giving paper cups better leak-proof performance.

[0004] However, using silicate glass powder as a paper filler also presents the following problems: the high surface energy of glass powder makes it prone to agglomeration and precipitation in the pulp. Agglomeration and precipitation lead to reduced paper uniformity and affect its mechanical properties. Summary of the Invention

[0005] One of the problems solved by this invention is how to provide a paper cup base paper with good uniformity and high mechanical properties.

[0006] To solve at least one of the above problems, the present invention provides a production process for paper cup base paper, the production process comprising:

[0007] S100, Preparation of fiber pulp;

[0008] S200: The fiber slurry is mixed with modified silicate glass powder to prepare a mixed slurry;

[0009] S300: The mixed slurry is subjected to wire forming, pressing and dewatering, and drying to obtain the paper cup base paper;

[0010] The modified silicate glass powder is prepared through the following steps:

[0011] S1. Mix and grind titanium oxide, sodium oxide, barium carbonate, calcium carbonate, boron oxide and silicon oxide evenly to obtain a glass matrix;

[0012] S2. The glass matrix is ​​heated and melted at a temperature of 1400℃ to 1600℃ to obtain molten glass;

[0013] S3. The molten glass is quenched with water and ground to obtain glass powder;

[0014] S4. The glass powder is fed into a fluidized bed, the polymer modifier is heated to 70°C to 80°C, and the polymer modifier is sprayed into the fluidized bed to obtain the modified silicate glass powder.

[0015] In any of the above technical solutions, in S1, by mass ratio, titanium oxide: sodium oxide: barium carbonate: calcium carbonate: boron oxide: silicon oxide = (1-2): (4-6): (5-10): (5-10): (10-20): (60-80).

[0016] In any of the above technical solutions, in S2, the heating and melting time is 2 hours to 2.5 hours.

[0017] In any of the above technical solutions, in S3, the glass powder is ground to 10nm to 100nm.

[0018] In any of the above technical solutions, in S4, the polymer modifier: glass powder ratio is (10-20):100 by mass.

[0019] In any of the above technical solutions, in S4, the polymer modifier includes: KH550 silane coupling agent: 15 to 25 parts by mass; polybutadiene epoxy resin with a molecular weight of 800 to 900: 20 to 30 parts by mass; and polyamide epichlorohydrin resin: 40 to 60 parts by mass.

[0020] In any of the above technical solutions, S100 specifically includes:

[0021] S110. Weigh the sugarcane bagasse and wood fiber separately;

[0022] S120. The sugarcane bagasse and the wood fiber are mixed, and water is added for pulping and refining. The speed of the refining machine is set to 1000 r / min to 1200 r / min, the refining time is 15 min to 20 min, and the beating degree is 70°SR to 80°SR to obtain the fiber pulp.

[0023] In any of the above technical solutions, in S110, by mass ratio, bagasse: wood fiber = (30-40): 100.

[0024] In any of the above technical solutions, S200 specifically includes:

[0025] S210. According to the mass ratio of polyethyleneimine: modified silicate glass powder: fiber slurry = (2-4): (6-8): 100, the fiber slurry is fed into the slurry mixing tank, and then the polyethyleneimine and the modified silicate glass powder are weighed and fed into the slurry mixing tank.

[0026] S220, gradually add aluminum sulfate until the pH value is adjusted to 7.5 to 8.5 to obtain the mixed slurry.

[0027] The present invention also provides a paper cup base paper, which is obtained by the production process of any of the above technical solutions.

[0028] Beneficial effects

[0029] This invention provides a production process for paper cup base paper. The process includes first preparing a fiber pulp; then mixing the fiber pulp with modified silicate glass powder to obtain a mixed pulp; and finally subjecting the mixed pulp to wire forming, pressing, dewatering, and drying to obtain the paper cup base paper. In this invention, silicate glass powder is used as an inorganic filler, which is added to the pulp to improve the mechanical strength of the paper. Considering that silicate glass powder is prone to agglomeration and precipitation in the pulp, this invention modifies the silicate glass powder. The modified silicate glass powder is prepared through the following steps: titanium oxide, sodium oxide, barium carbonate, calcium carbonate, boron oxide, and silicon oxide are mixed and ground uniformly to obtain a glass matrix; the glass matrix is ​​heated and melted at temperatures ranging from 1400°C to 1600°C to obtain a glass melt; the glass melt is water-quenched and ground to obtain glass powder; the glass powder is fed into a fluidized bed, and the polymer modifier is heated to 70°C to 80°C and sprayed into the fluidized bed to obtain the modified silicate glass powder. After obtaining the above glass powder, the present invention modifies the glass powder using a polymer modifier. The glass powder contacts the heated polymer modifier in the fluidized bed, and the polymer modifier coats the surface of the glass powder, reducing its surface energy and improving its compatibility with other raw materials in the paper pulp. This promotes the uniform and stable dispersion of the glass powder, avoids agglomeration and sedimentation of the glass powder in the pulp, and improves the uniformity and mechanical properties of the paper. Detailed Implementation

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, a detailed description of specific embodiments of the present invention will be provided below.

[0031] Unless otherwise specified, all reagents and raw materials used in this invention are commercially available. Experimental methods in the following examples that do not specify particular conditions should be performed according to conventional methods and conditions, or as selected in the product instructions.

[0032] This invention provides a production process for paper cup base paper. The production process adopted by this invention includes:

[0033] S100, Preparation of fiber pulp;

[0034] S200: The fiber slurry is mixed with modified silicate glass powder to prepare a mixed slurry;

[0035] S300: The mixed slurry is subjected to wire forming, pressing and dewatering, and drying to obtain the paper cup base paper.

[0036] Fiber pulp is the main constituent material of paper, providing its basic framework. These fibers interweave and bond to form the structure of paper, giving it a certain strength and stability.

[0037] Specifically, S100 includes:

[0038] S110. Weigh the sugarcane bagasse and wood fiber separately;

[0039] S120. The sugarcane bagasse and the wood fiber are mixed, and water is added for pulping and refining. The speed of the refining machine is set to 1000 r / min to 1200 r / min, the refining time is 15 min to 20 min, and the beating degree is 70°SR to 80°SR to obtain the fiber pulp.

[0040] Preferably, in some embodiments of the present invention, in S110, the sugarcane bagasse: wood fiber ratio is (30-40):100 by mass.

[0041] Wood fibers, due to their toughness and durability, can significantly improve the strength of paper. Compared to other fiber materials, such as cotton and hemp rope, wood fibers do not lose their strength even in humid environments. Sugarcane bagasse is an agricultural waste, and using it for papermaking can effectively reduce environmental pollution and resource waste. Compared to wood fibers, sugarcane bagasse has lower acquisition and processing costs and does not require logging, thus helping to protect forest resources. Furthermore, the production process of sugarcane bagasse paper is relatively environmentally friendly, and the remaining waste can be used as fertilizer, further reducing negative environmental impacts.

[0042] However, excessive addition of bagasse can reduce the mechanical properties of paper, decreasing its strength and durability. Therefore, this invention mixes modified silicate glass powder with fiber pulp to improve the mechanical properties of the paper.

[0043] In some embodiments of the present invention, S200 specifically includes:

[0044] S210. According to the mass ratio of polyethyleneimine: modified silicate glass powder: fiber slurry = (2-4): (6-8): 100, the fiber slurry is fed into the slurry mixing tank, and then the polyethyleneimine and the modified silicate glass powder are weighed and fed into the slurry mixing tank.

[0045] S220, gradually add aluminum sulfate until the pH value is adjusted to 7.5 to 8.5 to obtain the mixed slurry.

[0046] Polyethyleneimine is used as a wet strength agent. During the papermaking and pulping process, wet strength agents adsorb onto the negative charges on the fiber surface, forming cross-linked resin networks or gels. These substances reduce fiber swelling and increase the bonding force between fibers, thereby improving the wet strength of the paper. In addition to wet strength, wet strength agents can also improve the tensile strength, tear strength, and other mechanical properties of paper. These improvements make the paper more durable and reliable, meeting a wider range of application needs.

[0047] After pulping, the paper base needs to undergo a series of processes, including papermaking, pressing and dewatering, and drying, to complete the manufacturing of the base paper. Those skilled in the art can select and adjust the equipment and process parameters used in the papermaking, pressing, and drying processes according to actual needs. After obtaining the paper cup base paper, those skilled in the art can also choose whether calendering and sizing are necessary, depending on actual needs.

[0048] In some embodiments of the present invention, the modified silicate glass powder is prepared by the following steps:

[0049] S1. Mix and grind titanium oxide, sodium oxide, barium carbonate, calcium carbonate, boron oxide and silicon oxide evenly to obtain a glass matrix;

[0050] S2. The glass matrix is ​​heated and melted at a temperature of 1400℃ to 1600℃ to obtain molten glass;

[0051] S3. The molten glass is quenched with water and ground to obtain glass powder;

[0052] S4. The glass powder is fed into a fluidized bed, the polymer modifier is heated to 70°C to 80°C, and the polymer modifier is sprayed into the fluidized bed to obtain the modified silicate glass powder.

[0053] Preferably, in some embodiments of the present invention, in S1, the mass ratio of titanium oxide: sodium oxide: barium carbonate: calcium carbonate: boron oxide: silicon oxide is (1-2): (4-6): (5-10): (5-10): (10-20): (60-80).

[0054] More preferably, in some embodiments of the present invention, in S1, the mass ratio of titanium oxide: sodium oxide: barium carbonate: calcium carbonate: boron oxide: silicon oxide is 1:5:5:5:10:74.

[0055] In some embodiments of the present invention, in S2, the heating and melting time is 2 hours to 2.5 hours.

[0056] In some embodiments of the present invention, in step S3, the glass powder is ground to 10 nm to 100 nm.

[0057] In some embodiments of the present invention, in S4, the polymer modifier: glass powder = (10-20): 100 by mass ratio.

[0058] In the above steps, silica can improve the softening point and chemical stability of glass powder, and the strong network structure formed in the glass significantly enhances its hardness and strength. The introduction of boron oxide effectively reduces the coefficient of thermal expansion of the glass powder, a property that gives the paper cup base paper better heat resistance. Furthermore, boron oxide has excellent fluxing properties, promoting glass melting and clarification. Calcium carbonate also acts as a flux, lowering the melting point of the glass and thus promoting melting. The addition of barium carbonate significantly improves the hardness and heat resistance of the glass powder. Titanium oxide, as an antibacterial agent, can generate electron-hole pairs through photocatalysis. These electrons and holes have strong oxidation and reduction effects. During photocatalysis, electrons can react with oxygen molecules to generate free radicals, such as superoxide radicals and hydroxyl radicals. These free radicals can attack bacterial cell walls and cell membranes, destroying their structure and causing bacteria to lose their vitality, thereby inhibiting and killing bacteria. Overall, the addition of glass powder plays an important role in improving the mechanical and heat resistance properties of the base paper.

[0059] In some embodiments of the present invention, in step S4, the polymer modifier comprises: KH550 silane coupling agent: 15 to 25 parts by mass; polybutadiene epoxy resin with a molecular weight of 800 to 900: 20 to 30 parts by mass; and polyamide epichlorohydrin resin: 40 to 60 parts by mass. The KH550 silane coupling agent (also known as γ-aminopropyltriethoxysilane) contains two different active groups—amino and ethoxy—which can undergo coupling reactions with organic polymers and inorganic fillers, thereby enhancing their adhesion. The polybutadiene epoxy resin can adjust the viscosity of the polymer modifier, allowing it to uniformly and continuously coat the surface of the glass powder. The present invention uses polyamide epichlorohydrin resin as the main raw material for the polymer modifier. Its advantage is that, since polyethyleneimine contains amino groups, epoxy groups, and aziridine-type cations, while the surface of plant fibers used in papermaking has reactive groups such as hydroxyl groups, aldehyde groups, and carboxyl groups, the two can undergo a cross-linking reaction. Forming a uniform and continuous polymer film on the surface of glass powder not only reduces the surface energy of the glass powder and improves its dispersion stability, but also enhances the compatibility between the glass powder and fibers. In particular, after the paper is soaked in water, the polyethyleneimine on the surface of the glass powder cross-links into a network structure, which strengthens the bond between the glass powder and fibers, improves the mechanical properties and tear resistance of the paper in humid environments, and makes the paper more durable.

[0060] Example 1

[0061] In this embodiment, a series of paper cup base paper samples were prepared. The raw material ratios are shown in Table 1. The specific preparation steps are as follows:

[0062] S1. Weigh titanium oxide, sodium oxide, barium carbonate, calcium carbonate, boron oxide and silicon oxide according to the mass ratio in Table 1. Dry grind them for 2 hours in a planetary ball mill using zirconia balls as the grinding medium to obtain a glass matrix.

[0063] S2. Place the glass matrix into a crucible and send it into a resistance furnace. Heat the furnace to a temperature of 1450°C to 1500°C and hold it at that temperature to melt the glass and obtain molten glass.

[0064] S3. Take the molten glass out of the resistance furnace, pour it into cold water from the crucible for water quenching, and then grind it to between 10nm and 100nm to obtain glass powder.

[0065] S4. According to the mass ratio in Table 1, the glass powder is fed into a fluidized bed. At the same time, the polymer modifier prepared according to the mass ratio in Table 1 is heated to 70°C to 80°C and then sprayed into the fluidized bed so that the polymer modifier coats at least part of the surface of the glass powder. The powder is collected to obtain the modified silicate glass powder.

[0066] S5. Weigh the sugarcane bagasse and wood fiber separately according to the mass ratio in Table 1; mix the sugarcane bagasse and the wood fiber, add water and perform pulping and refining treatment. Set the speed of the refining machine to 1000 r / min, the refining time to 20 min, and the beating degree to 70°SR to obtain the fiber pulp.

[0067] S6. According to the mass ratio in Table 1, the fiber slurry is fed into the mixing tank, and then the polyethyleneimine and the modified silicate glass powder are weighed and fed into the mixing tank. Aluminum sulfate is gradually added until the pH value is adjusted to 7.5 to obtain the mixed slurry.

[0068] S7. A two-layer wire forming and filtering papermaking process is adopted, in which the mixed pulp flows out from the headbox to the circulating forming wire and is evenly interwoven. The papermaking process is carried out at a speed of 700m / min. After the papermaking process on the wire, the wet paper removed from the wire is guided to the press rolls. Under the pressure of the press rolls, the paper is dewatered. When the dryness is reduced to about 45%, the dewatered wet paper is dried by steam heating in a drying device consisting of a drying cylinder and a sealed air hood. The temperature of the drying cylinder is between 70℃ and 110℃ to obtain the paper cup base paper.

[0069] Table 1

[0070]

[0071] The performance test results of samples 1 to 8 are shown in Table 2.

[0072] Table 2

[0073] performance Sample 1 Sample 2 Sample 3 Sample 4 Tensile strength (N·m / g) 79.48 74.84 78.28 72.52 <![CDATA[Bursting strength index (KPa·m 2 / g)]]> 7.2 6.2 6.9 6.0 <![CDATA[Tear index (mN m 2 / g)]]> 9.75 7.58 9.17 7.15 performance Sample 5 Sample 6 Sample 7 Sample 8 Tensile strength (N·m / g) 74.51 70.27 77.45 73.42 <![CDATA[Bursting strength index (KPa·m 2 / g)]]> 6.1 5.8 6.8 5.9 <![CDATA[Tear index (mN m 2 / g)]]> 7.46 7.02 8.78 7.59

[0074] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A production process for paper cup base paper, characterized in that, The production process includes: S100, Preparation of fiber pulp; S200: Polyethyleneimine, the fiber slurry, modified silicate glass powder, and aluminum sulfate are mixed to form a slurry, thereby obtaining a mixed slurry; S300: The mixed slurry is subjected to wire forming, pressing and dewatering, and drying to obtain the paper cup base paper; The modified silicate glass powder is prepared through the following steps: S1. Mix and grind titanium oxide, sodium oxide, barium carbonate, calcium carbonate, boron oxide and silicon oxide evenly to obtain a glass matrix; S2. The glass matrix is ​​heated and melted at a temperature of 1400°C to 1600°C to obtain molten glass; S3. The molten glass is quenched with water and ground to obtain glass powder; S4. The glass powder is fed into a fluidized bed, the polymer modifier is heated to 70°C to 80°C, and the polymer modifier is sprayed into the fluidized bed to obtain the modified silicate glass powder. In S4, the polymer modifier includes: KH550 silane coupling agent: 15 to 25 parts by weight; Polybutadiene epoxy resin with a molecular weight of 800 to 900: 20 to 30 parts by weight; Polyamide epichlorohydrin resin: 40 to 60 parts by weight.

2. The production process according to claim 1, characterized in that, In S1, by mass ratio, titanium oxide: sodium oxide: barium carbonate: calcium carbonate: boron oxide: silicon oxide = (1-2): (4-6): (5-10): (5-10): (10-20): (60-80).

3. The production process according to claim 1, characterized in that, In S2, the heating and melting time is 2 hours to 2.5 hours.

4. The production process according to claim 1, characterized in that, In S3, the glass powder is ground to 10 nm to 100 nm.

5. The production process according to claim 1, characterized in that, In S4, the polymer modifier : glass powder ratio is (10-20) : 100 by mass.

6. The production process according to any one of claims 1 to 4, characterized in that, S100 specifically includes: S110. Weigh the sugarcane bagasse and wood fiber separately; S120. The sugarcane bagasse and the wood fiber are mixed, and water is added for pulping and refining. The speed of the refining machine is set to 1000 r / min to 1200 r / min, the refining time is 15 min to 20 min, and the beating degree is 70°SR to 80°SR to obtain the fiber pulp.

7. The production process according to claim 6, characterized in that, In S110, by mass ratio, bagasse: wood fiber = (30-40):

100.

8. The production process according to any one of claims 1 to 4, characterized in that, S200 specifically includes: S210. According to the mass ratio of polyethyleneimine: modified silicate glass powder: fiber slurry = (2-4): (6-8): 100, the fiber slurry is sent into the slurry mixing tank, and then the polyethyleneimine and the modified silicate glass powder are weighed and sent into the slurry mixing tank. S220, gradually add aluminum sulfate until the pH value is adjusted to 7.5 to 8.5 to obtain the mixed slurry.

9. A type of paper cup base paper, characterized in that, The paper cup base paper is obtained using the production process described in any one of claims 1 to 8.

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