Compression-resistant recycled paper tube for packaging and processing technology of compression-resistant recycled paper tube

Abstract

The invention relates to the technical field of recycled paper tubes, and particularly discloses a compression-resistant recycled paper tube for packaging and a processing technology thereof.Chitosan composite modified nanocrystalline cellulose is added into paper pulp fibers to serve as a reinforcing agent of paper pulp, so that the paper pulp fibers are promoted to form a cross-linked network structure, and the bonding capacity among the paper pulp fibers is improved; the surface of the finished paper is coated with the surface sizing agent composed of the lignin cationic surface active agent and the rosin, the mechanical performance of the finished paper material is improved, the non-polar hydrophobic end of the sizing agent forms a layer of hydrophobic film on the surface of the paper pulp fiber, and the hydrophobicity of the finished paper material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of recycled paper tubes, and in particular to a compression-resistant recycled paper tube for packaging and a processing technology thereof. Background Art

[0002] Paper is a material that combines the advantages of a wide source of raw materials, low production cost, easy processing, safety and hygiene, and easy composite processing.

[0003] Waste paper recycling has alleviated resource constraints to a certain extent. However, with the continuous recycling of waste paper, not only are pulp fibers increasingly damaged during the pulping and papermaking process, shortening them and weakening the bonding between the short fibers, but they also become keratinized, reducing their ability to absorb and swell. This results in a decline in the physical properties of recycled paper, such as bursting strength, tensile strength, and ring crush strength, making it difficult to meet user requirements. Furthermore, the hydrophilic nature of paper causes moisture in the air or liquids inside the packaging to invade the packaging during transportation and storage, leading to a decrease in the physical properties of the packaging material. This remains a pressing issue in the production of packaging paper. Summary of the Invention

[0004] The purpose of the present invention is to provide a compression-resistant recycled paper tube for packaging and a processing technology thereof, so as to solve the problem that the mechanical properties of the recycled paper tube for packaging are relatively weak.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A processing technology for a compression-resistant recycled paper tube for packaging, specifically comprising:

[0007] The collected waste paper is crushed, and after impurities are screened out, it is added into deionized water and soaked for 12 to 24 hours. After soaking, it is decomposed and pulped, and the pulping time is controlled to be 15 to 45 minutes, and the pulping speed is 5000 to 10000 rpm. Then the impurities are removed to obtain waste paper pulp, and the waste paper pulp is mixed with chitosan composite modification and reinforcement agent, stirred evenly, and then put on the net for papermaking. After shaping and drying, paper tube base paper is obtained, and lignin rosin sizing solution is coated on the surface of the paper tube base paper, dried, and rolled to obtain pressure-resistant recycled paper tube for packaging.

[0008] As a limitation of the present invention, the mass ratio of waste paper to chitosan composite modifier and enhancer is (90-120):(0.4-0.8).

[0009] As a limitation of the present invention, the preparation method of the chitosan modified reinforcing agent is:

[0010] Adding ethylene glycol diethyl ether diamine tetraacetic acid to deionized water, adjusting the pH to 12-13 with sodium hydroxide, and stirring uniformly to obtain an ethylene glycol diethyl ether diamine tetraacetic acid solution, adding sodium hydrogen tripolyphosphate to the solution, stirring uniformly, and heating at 60-70° C. for 18-24 hours. After the reaction is complete, adding nanocrystalline cellulose, followed by ultrasonic dispersion for 20-30 minutes to obtain a cellulose dispersion, heating the cellulose dispersion at 110-120° C. for 5-6 hours, filtering after the reaction is complete, and drying to obtain ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose.

[0011] Acetic acid and deionized water are mixed and stirred evenly to obtain an acetic acid solution. Chitosan is added to the acetic acid solution and stirred evenly to fully dissolve to obtain a chitosan acetic acid solution. Ethylene glycol diethyl ether diamine tetraacetic acid-modified cellulose is mixed with deionized water and stirred evenly, and then the chitosan acetic acid solution is added. The mixture is stirred and reacted at 75-85° C. for 2-4 hours. After the reaction is completed, it is filtered and dried to obtain a chitosan composite modified enhancer.

[0012] As a limitation of the present invention, the mass ratio of ethylene glycol diethyl ether diamine tetraacetic acid, sodium tripolyphosphate, and nanocrystalline cellulose is (4-6):(0.4-0.6):(1-10).

[0013] As a limitation of the present invention, the mass ratio of the acetic acid, chitosan, and ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose is (0.5-1):(5-10):(1-3).

[0014] As a limitation of the present invention, the preparation method of the lignin rosin glue sizing solution is:

[0015] A lignin surfactant, a cationic polyacrylamide, and a nonionic polyacrylamide are added to deionized water, and the mixture is stirred and dispersed at 70-80° C. and 500-700 rpm for 20-40 minutes to obtain a lignin emulsion. Rosin is heated and melted at 125-135° C. and 500-700 rpm. The lignin emulsion is then dripped into the melted rosin solution, the rotation speed is adjusted to 1500-2000 rpm, and deionized water is added to form a lignin rosin glue emulsion. The lignin rosin glue emulsion is quickly cooled to room temperature with ice water, and then high-pressure homogenized for 5-10 minutes to obtain a lignin rosin sizing solution.

[0016] As a limitation of the present invention, the lignin rosin sizing solution includes, by mass, 15 to 25 parts of lignin surfactant, 18 to 22 parts of cationic polyacrylamide, 8 to 12 parts of nonionic polyacrylamide, and 15 to 25 parts of rosin.

[0017] As a limitation of the present invention, the preparation method of the lignin surfactant is:

[0018] The lignin raw material is added to a 95% ethanol aqueous solution, stirred at 300-500 rpm at room temperature for 1-3 hours, and then vacuum filtered to filter out the undissolved portion. Subsequently, the undissolved portion is added to a 70% ethanol aqueous solution, stirred at 300-500 rpm at room temperature for 1-3 hours, vacuum filtered, and the undissolved portion is filtered out again. The product is dried at 50-60° C. to obtain high molecular weight lignin, and the filtrate from the two filtrations is distilled to recover ethanol for reuse;

[0019] Sodium hydroxide is dissolved in deionized water, stirred evenly, and then high molecular weight lignin is added. After mixing evenly, epichlorohydrin is added in a constant temperature water bath at 60-70°C and 300-500 rpm and reacted for 3-5 hours. After the reaction is completed, the pH is adjusted to 7-8 with sodium dihydrogen phosphate, and the mixture is rinsed with deionized water, filtered, and dried to obtain epoxidized high molecular weight lignin. Sodium hydroxide is dissolved in deionized water, stirred evenly, and then the obtained epoxidized high molecular weight lignin is added. Triethylamine is slowly added in a constant temperature water bath at 60-70°C and 300-500 rpm and reacted for 3-5 hours. After the reaction is completed, the pH is adjusted to 2-3 with hydrochloric acid, and the mixture is washed with deionized water, filtered, and dried to obtain a lignin surfactant.

[0020] As a limitation of the present invention, the mass ratio of the high molecular weight lignin, epichlorohydrin and triethylamine is (2-6):(15-25):(5-15).

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention uses diethylenetriaminepentaacetic acid to modify nanocrystalline cellulose and cross-links it with chitosan to form a chitosan-composite modified paper strengthening agent. The nanocrystalline cellulose can fill the gaps between pulp fibers, prompting the pulp fibers to form a cross-linked network structure, increasing the bonding ability between the pulp fibers, and thus improving the mechanical properties of the paper material. In addition, a large number of active groups on the surface of the nanocrystalline cellulose can increase the adsorption of cationic groups, which is beneficial to the bonding of cationic sizing agents with pulp fibers. After being activated with diethylenetriaminepentaacetic acid, the nanocrystalline cellulose is cross-linked with chitosan. The chitosan surface contains abundant functional groups such as hydroxyl, amino, and acetylamino groups. The chitosan surface forms chemical bonds and generates hydrogen bonds, making the fiber cross-linking degree more complex, acting as a bridge between the pulp fibers and the cations, and further enhancing the mechanical properties of the pulp fibers and the paper material.

[0023] High molecular weight lignin is separated by lignin fractionation, the chemical structure and molecular weight instability of lignin are improved, and then it is modified with epichlorohydrin and triethylamine to synthesize a lignin cationic surfactant, which finally forms a surface sizing agent for paper together with rosin. The cationic quaternary ammonium groups grafted on the lignin cationic surfactant help to enhance the electrostatic adsorption between the sizing agent and the pulp fiber, thereby improving the sizing performance. Lignin has hydroxyl and carboxyl groups, which can produce hydrogen bonds with the fiber hydroxyl groups, which is beneficial to improving the mechanical properties of the paper material. After drying, the polar hydroxyl and carboxyl hydrophilic groups on the sizing agent adsorbed on the surface of the pulp fiber are combined with the fiber surface, and the non-polar hydrophobic end of the sizing agent will be exposed on the surface of the pulp fiber, forming a hydrophobic film on the surface of the pulp fiber, thereby improving the hydrophobicity of the paper material. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0025] Waste paper (national waste COCC12#) was purchased from the market, lignin (product number: S19288, purity: 99%) and rosin (product number: W11064, purity: 99%) came from Yuanye Bio, nanocrystalline cellulose (diameter: 4-10nm) came from Qihong Technology, and cationic polyacrylamide (Mw=500w) and non-ionic polyacrylamide (Mw=800w) came from Henan Yusheng Chemical.

[0026] Example 1: A processing technology for a compression-resistant recycled paper tube for packaging, specifically comprising:

[0027] Step 1: Preparation of ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose

[0028] Add 5 g of ethylene glycol diethyl ether diamine tetraacetic acid to 30 g of deionized water, adjust the pH to 12 with sodium hydroxide, stir evenly to obtain an ethylene glycol diethyl ether diamine tetraacetic acid solution, add 0.5 g of sodium hydrogen tripolyphosphate to the solution, stir evenly, heat to react at 60°C for 24 hours, and after the reaction is completed, add 5 g of nanocrystalline cellulose, followed by ultrasonic dispersion for 30 minutes to obtain a cellulose dispersion, and heat the cellulose dispersion at 120°C for reaction for 5 hours. After the reaction is completed, filter and dry to obtain ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose.

[0029] Step 2: Preparation of chitosan composite modified enhancer

[0030] 0.75 g of acetic acid was mixed with 50 g of deionized water and stirred to obtain an acetic acid solution. 5 g of chitosan was added to the acetic acid solution and stirred to dissolve the mixture to obtain a chitosan acetic acid solution. 1.5 g of ethylene glycol diethyl ether diamine tetraacetic acid-modified cellulose was mixed with 50 g of deionized water and stirred to obtain a chitosan acetic acid solution. The mixture was stirred and reacted at 85° C. for 3 h. After the reaction was completed, the mixture was filtered and dried to obtain a chitosan composite modified enhancer.

[0031] Step 3: Preparation of high molecular weight lignin

[0032] The lignin raw material was added to a 95% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, and then vacuum filtered to filter out the undissolved portion. Subsequently, the undissolved portion was added to a 70% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, vacuum filtered, and the undissolved portion was filtered out again. The product was dried at 50°C to obtain high molecular weight lignin. The filtrate from the two filtrations was distilled to recover ethanol for reuse.

[0033] Step 4: Preparation of lignin surfactant

[0034] Dissolve 14.4g of sodium hydroxide in 60g of deionized water, stir evenly, add 4g of high molecular weight lignin, mix evenly, slowly add 20g of epichlorohydrin at 500rpm in a constant temperature water bath at 65°C and react for 5h. After the reaction is completed, adjust the pH to 7 with sodium dihydrogen phosphate, rinse with deionized water, filter, and dry to obtain epoxidized high molecular weight lignin. Dissolve 0.36g of sodium hydroxide in 30g of deionized water, stir evenly, add the obtained epoxidized high molecular weight lignin, slowly add 11g of triethylamine at 500rpm in a constant temperature water bath at 65°C and react for 4h. After the reaction is completed, adjust the pH to 2 with hydrochloric acid, wash with deionized water, filter, and dry to obtain a lignin surfactant.

[0035] Step 5: Prepare lignin rosin sizing solution

[0036] 20 g of lignin surfactant, 20 g of cationic polyacrylamide, and 10 g of nonionic polyacrylamide were added to 100 g of deionized water, and the mixture was stirred and dispersed at 80° C. and 500 rpm for 30 min to obtain a lignin emulsion. 20 g of rosin was heated and melted at 135° C. and 500 rpm, and the lignin emulsion was then dropped into the melted rosin solution. The rotation speed was adjusted to 2000 rpm, and 900 g of deionized water was added to form a lignin rosin glue emulsion. The lignin rosin glue emulsion was quickly cooled to room temperature with ice water, and then high-pressure homogenized for 5 min to obtain a lignin rosin sizing solution.

[0037] Step 6: Prepare the compression-resistant recycled paper tube for packaging

[0038] The collected waste paper was crushed, and after impurities were screened out, 20 g was weighed and added to 980 g of deionized water to soak for 24 hours. After soaking, the waste paper and the deionized water were transferred to a beater, and the waste paper was decomposed and beaten. The beating time was controlled to be 30 minutes and the beating speed was 8000 rpm. Then, the impurities were removed by a sieving instrument to obtain waste paper pulp. The waste paper pulp was mixed with 0.08 g of chitosan composite modifier and enhancer, stirred evenly, and then put on the screen for papermaking. It was shaped at 5 MPa and dried at 100 ° C to obtain a quantitative 80 g / m 2 The paper tube base paper is coated with lignin rosin sizing liquid on the surface of the paper tube base paper with a coating machine. The coating machine speed is set to 50mm / s and the coating amount is 8g / m 2 , dried at 95℃, rolled into a roll, and obtained a compression-resistant recycled paper tube for packaging.

[0039] Example 2: A processing technology for a compression-resistant recycled paper tube for packaging, specifically comprising:

[0040] Step 1: Preparation of ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose

[0041] Add 5 g of ethylene glycol diethyl ether diamine tetraacetic acid to 30 g of deionized water, adjust the pH to 12 with sodium hydroxide, stir evenly to obtain an ethylene glycol diethyl ether diamine tetraacetic acid solution, add 0.5 g of sodium hydrogen tripolyphosphate to the solution, stir evenly, heat to react at 60°C for 24 hours, and after the reaction is completed, add 5 g of nanocrystalline cellulose, followed by ultrasonic dispersion for 30 minutes to obtain a cellulose dispersion, and heat the cellulose dispersion at 120°C for reaction for 5 hours. After the reaction is completed, filter and dry to obtain ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose.

[0042] Step 2: Preparation of chitosan composite modified enhancer

[0043] 0.75 g of acetic acid was mixed with 50 g of deionized water and stirred to obtain an acetic acid solution. 5 g of chitosan was added to the acetic acid solution and stirred to dissolve the mixture to obtain a chitosan acetic acid solution. 1.5 g of ethylene glycol diethyl ether diamine tetraacetic acid-modified cellulose was mixed with 50 g of deionized water and stirred to obtain a chitosan acetic acid solution. The mixture was stirred and reacted at 85° C. for 3 h. After the reaction was completed, the mixture was filtered and dried to obtain a chitosan composite modified enhancer.

[0044] Step 3: Preparation of high molecular weight lignin

[0045] The lignin raw material was added to a 95% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, and then vacuum filtered to filter out the undissolved portion. Subsequently, the undissolved portion was added to a 70% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, vacuum filtered, and the undissolved portion was filtered out again. The product was dried at 50°C to obtain high molecular weight lignin. The filtrate from the two filtrations was distilled to recover ethanol for reuse.

[0046] Step 4: Preparation of lignin surfactant

[0047] Dissolve 14.4g of sodium hydroxide in 60g of deionized water, stir evenly, add 4g of high molecular weight lignin, mix evenly, slowly add 20g of epichlorohydrin at 500rpm in a constant temperature water bath at 65°C and react for 5h. After the reaction is completed, adjust the pH to 7 with sodium dihydrogen phosphate, rinse with deionized water, filter, and dry to obtain epoxidized high molecular weight lignin. Dissolve 0.36g of sodium hydroxide in 30g of deionized water, stir evenly, add the obtained epoxidized high molecular weight lignin, slowly add 11g of triethylamine at 500rpm in a constant temperature water bath at 65°C and react for 4h. After the reaction is completed, adjust the pH to 2 with hydrochloric acid, wash with deionized water, filter, and dry to obtain a lignin surfactant.

[0048] Step 5: Prepare lignin rosin sizing solution

[0049] 20 g of lignin surfactant, 20 g of cationic polyacrylamide, and 10 g of nonionic polyacrylamide were added to 100 g of deionized water, and the mixture was stirred and dispersed at 80° C. and 500 rpm for 30 min to obtain a lignin emulsion. 20 g of rosin was heated and melted at 135° C. and 500 rpm, and the lignin emulsion was then dropped into the melted rosin solution. The rotation speed was adjusted to 2000 rpm, and 900 g of deionized water was added to form a lignin rosin glue emulsion. The lignin rosin glue emulsion was quickly cooled to room temperature with ice water, and then high-pressure homogenized for 5 min to obtain a lignin rosin sizing solution.

[0050] Step 6: Prepare the compression-resistant recycled paper tube for packaging

[0051] The collected waste paper was crushed, and after impurities were screened out, 20 g was weighed and added to 980 g of deionized water to soak for 24 hours. After the soaking was completed, the waste paper and the deionized water were transferred to a beater, and the waste paper was decomposed and beaten. The beating time was controlled to be 30 minutes and the beating speed was 8000 rpm. Then, the impurities were removed by a sieving instrument to obtain waste paper pulp. The waste paper pulp was mixed with 0.12 g of chitosan composite modifier and enhancer, stirred evenly, and then put on the screen for papermaking. It was shaped at 5 MPa and dried at 100 ° C to obtain a quantitative 80 g / m 2The paper tube base paper is coated with lignin rosin sizing liquid on the surface of the paper tube base paper with a coating machine. The coating machine speed is set to 50mm / s and the coating amount is 8g / m 2 , dried at 95℃, rolled into a roll, and obtained a compression-resistant recycled paper tube for packaging.

[0052] Example 3: A processing technology for a compression-resistant recycled paper tube for packaging, specifically comprising:

[0053] Step 1: Preparation of ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose

[0054] Add 5 g of ethylene glycol diethyl ether diamine tetraacetic acid to 30 g of deionized water, adjust the pH to 12 with sodium hydroxide, stir evenly to obtain an ethylene glycol diethyl ether diamine tetraacetic acid solution, add 0.5 g of sodium hydrogen tripolyphosphate to the solution, stir evenly, heat to react at 60°C for 24 hours, and after the reaction is completed, add 5 g of nanocrystalline cellulose, followed by ultrasonic dispersion for 30 minutes to obtain a cellulose dispersion, and heat the cellulose dispersion at 120°C for reaction for 5 hours. After the reaction is completed, filter and dry to obtain ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose.

[0055] Step 2: Preparation of chitosan composite modified enhancer

[0056] 0.75 g of acetic acid was mixed with 50 g of deionized water and stirred to obtain an acetic acid solution. 5 g of chitosan was added to the acetic acid solution and stirred to dissolve the mixture to obtain a chitosan acetic acid solution. 1.5 g of ethylene glycol diethyl ether diamine tetraacetic acid-modified cellulose was mixed with 50 g of deionized water and stirred to obtain a chitosan acetic acid solution. The mixture was stirred and reacted at 85° C. for 3 h. After the reaction was completed, the mixture was filtered and dried to obtain a chitosan composite modified enhancer.

[0057] Step 3: Preparation of high molecular weight lignin

[0058] The lignin raw material was added to a 95% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, and then vacuum filtered to filter out the undissolved portion. Subsequently, the undissolved portion was added to a 70% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, vacuum filtered, and the undissolved portion was filtered out again. The product was dried at 50°C to obtain high molecular weight lignin. The filtrate from the two filtrations was distilled to recover ethanol for reuse.

[0059] Step 4: Preparation of lignin surfactant

[0060] Dissolve 14.4g of sodium hydroxide in 60g of deionized water, stir evenly, add 4g of high molecular weight lignin, mix evenly, slowly add 20g of epichlorohydrin at 500rpm in a constant temperature water bath at 65°C and react for 5h. After the reaction is completed, adjust the pH to 7 with sodium dihydrogen phosphate, rinse with deionized water, filter, and dry to obtain epoxidized high molecular weight lignin. Dissolve 0.36g of sodium hydroxide in 30g of deionized water, stir evenly, add the obtained epoxidized high molecular weight lignin, slowly add 11g of triethylamine at 500rpm in a constant temperature water bath at 65°C and react for 4h. After the reaction is completed, adjust the pH to 2 with hydrochloric acid, wash with deionized water, filter, and dry to obtain a lignin surfactant.

[0061] Step 5: Prepare lignin rosin sizing solution

[0062] 20 g of lignin surfactant, 20 g of cationic polyacrylamide, and 10 g of nonionic polyacrylamide were added to 100 g of deionized water, and the mixture was stirred and dispersed at 80° C. and 500 rpm for 30 min to obtain a lignin emulsion. 20 g of rosin was heated and melted at 135° C. and 500 rpm, and the lignin emulsion was then dropped into the melted rosin solution. The rotation speed was adjusted to 2000 rpm, and 900 g of deionized water was added to form a lignin rosin glue emulsion. The lignin rosin glue emulsion was quickly cooled to room temperature with ice water, and then high-pressure homogenized for 5 min to obtain a lignin rosin sizing solution.

[0063] Step 6: Prepare the compression-resistant recycled paper tube for packaging

[0064] The collected waste paper was crushed, and after impurities were screened out, 20 g was weighed and added into 980 g deionized water for soaking for 24 h. After soaking, the waste paper and the deionized water were transferred to a beater for decomposition and beating. The beating time was controlled to be 30 min and the beating speed was 8000 rpm. Then, the impurities were removed by a sieving instrument to obtain waste paper pulp. The waste paper pulp was mixed with 0.16 g chitosan composite modifier and enhancer, stirred evenly, and then put on the screen for papermaking. It was shaped at 5 MPa and dried at 100 ° C to obtain a quantitative 80 g / m 2 The paper tube base paper is coated with lignin rosin sizing liquid on the surface of the paper tube base paper with a coating machine. The coating machine speed is set to 50mm / s and the coating amount is 8g / m 2 , dried at 95℃, rolled into a roll, and obtained a compression-resistant recycled paper tube for packaging.

[0065] Based on Example 1, control experiments were conducted, specifically Comparative Example 1, Comparative Example 2, and Comparative Example 3, as described below:

[0066] Comparative Example 1: This comparative example relates to a processing technology for a compression-resistant recycled paper tube for packaging. The difference from Example 1 is that the sizing liquid is a rosin sizing dispersion, specifically:

[0067] Step 1: Preparation of ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose

[0068] Add 5 g of ethylene glycol diethyl ether diamine tetraacetic acid to 30 g of deionized water, adjust the pH to 12 with sodium hydroxide, stir evenly to obtain an ethylene glycol diethyl ether diamine tetraacetic acid solution, add 0.5 g of sodium hydrogen tripolyphosphate to the solution, stir evenly, heat to react at 60°C for 24 hours, and after the reaction is completed, add 5 g of nanocrystalline cellulose, followed by ultrasonic dispersion for 30 minutes to obtain a cellulose dispersion, and heat the cellulose dispersion at 120°C for reaction for 5 hours. After the reaction is completed, filter and dry to obtain ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose.

[0069] Step 2: Preparation of chitosan composite modified enhancer

[0070] 0.75 g of acetic acid was mixed with 50 g of deionized water and stirred to obtain an acetic acid solution. 5 g of chitosan was added to the acetic acid solution and stirred to dissolve the mixture to obtain a chitosan acetic acid solution. 1.5 g of ethylene glycol diethyl ether diamine tetraacetic acid-modified cellulose was mixed with 50 g of deionized water and stirred to obtain a chitosan acetic acid solution. The mixture was stirred and reacted at 85° C. for 3 h. After the reaction was completed, the mixture was filtered and dried to obtain a chitosan composite modified enhancer.

[0071] Step 3: Preparation of high molecular weight lignin

[0072] The lignin raw material was added to a 95% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, and then vacuum filtered to filter out the undissolved portion. Subsequently, the undissolved portion was added to a 70% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, vacuum filtered, and the undissolved portion was filtered out again. The product was dried at 50°C to obtain high molecular weight lignin. The filtrate from the two filtrations was distilled to recover ethanol for reuse.

[0073] Step 4: Prepare rosin glue dispersion

[0074] 20 g of rosin was heated and melted, and then added to 900 g of deionized water. After stirring evenly, high pressure homogenization and emulsification were performed for 5 minutes to obtain a rosin glue dispersion.

[0075] Step 5: Prepare the compression-resistant recycled paper tube for packaging

[0076] The collected waste paper was crushed, and after impurities were screened out, 20 g was weighed and added to 980 g of deionized water to soak for 24 hours. After soaking, the waste paper and the deionized water were transferred to a beater, and the waste paper was decomposed and beaten. The beating time was controlled to be 30 minutes and the beating speed was 8000 rpm. Then, the impurities were removed by a sieving instrument to obtain waste paper pulp. The waste paper pulp was mixed with 0.08 g of chitosan composite modifier and enhancer, stirred evenly, and then put on the screen for papermaking. It was shaped at 5 MPa and dried at 100 ° C to obtain a quantitative 80 g / m 2 The paper tube base paper is coated with lignin rosin sizing liquid on the surface of the paper tube base paper with a coating machine. The coating machine speed is set to 50mm / s and the coating amount is 8g / m 2 , dried at 95℃, rolled into a roll, and obtained a compression-resistant recycled paper tube for packaging.

[0077] Comparative Example 2: This comparative example relates to a processing technology for a compression-resistant recycled paper tube for packaging. The difference from Example 1 is that the reinforcing agent is ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose, specifically:

[0078] Step 1: Preparation of ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose

[0079] Add 5 g of ethylene glycol diethyl ether diamine tetraacetic acid to 30 g of deionized water, adjust the pH to 12 with sodium hydroxide, stir evenly to obtain an ethylene glycol diethyl ether diamine tetraacetic acid solution, add 0.5 g of sodium hydrogen tripolyphosphate to the solution, stir evenly, heat to react at 60°C for 24 hours, and after the reaction is completed, add 5 g of nanocrystalline cellulose, followed by ultrasonic dispersion for 30 minutes to obtain a cellulose dispersion, and heat the cellulose dispersion at 120°C for reaction for 5 hours. After the reaction is completed, filter and dry to obtain ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose.

[0080] Step 3: Preparation of high molecular weight lignin

[0081] The lignin raw material was added to a 95% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, and then vacuum filtered to filter out the undissolved portion. Subsequently, the undissolved portion was added to a 70% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, vacuum filtered, and the undissolved portion was filtered out again. The product was dried at 50°C to obtain high molecular weight lignin. The filtrate from the two filtrations was distilled to recover ethanol for reuse.

[0082] Step 4: Preparation of lignin surfactant

[0083] Dissolve 14.4g of sodium hydroxide in 60g of deionized water, stir evenly, add 4g of high molecular weight lignin, mix evenly, slowly add 20g of epichlorohydrin at 500rpm in a constant temperature water bath at 65°C and react for 5h. After the reaction is completed, adjust the pH to 7 with sodium dihydrogen phosphate, rinse with deionized water, filter, and dry to obtain epoxidized high molecular weight lignin. Dissolve 0.36g of sodium hydroxide in 30g of deionized water, stir evenly, add the obtained epoxidized high molecular weight lignin, slowly add 11g of triethylamine at 500rpm in a constant temperature water bath at 65°C and react for 4h. After the reaction is completed, adjust the pH to 2 with hydrochloric acid, wash with deionized water, filter, and dry to obtain a lignin surfactant.

[0084] Step 5: Prepare lignin rosin sizing solution

[0085] 20 g of lignin surfactant, 20 g of cationic polyacrylamide, and 10 g of nonionic polyacrylamide were added to 100 g of deionized water, and the mixture was stirred and dispersed at 80° C. and 500 rpm for 30 min to obtain a lignin emulsion. 20 g of rosin was heated and melted at 135° C. and 500 rpm, and the lignin emulsion was then dropped into the melted rosin solution. The rotation speed was adjusted to 2000 rpm, and 900 g of deionized water was added to form a lignin rosin glue emulsion. The lignin rosin glue emulsion was quickly cooled to room temperature with ice water, and then high-pressure homogenized for 5 min to obtain a lignin rosin sizing solution.

[0086] Step 6: Prepare the compression-resistant recycled paper tube for packaging

[0087] The collected waste paper was crushed, and after impurities were screened out, 20 g was weighed and added to 980 g of deionized water to soak for 24 hours. After soaking, the waste paper and the deionized water were transferred to a beater, and the waste paper was decomposed and beaten. The beating time was controlled to be 30 minutes and the beating speed was 8000 rpm. Then, the impurities were removed by a sieving instrument to obtain waste paper pulp. The waste paper pulp was mixed with 0.08 g of chitosan composite modifier and enhancer, stirred evenly, and then put on the screen for papermaking. It was shaped at 5 MPa and dried at 100 ° C to obtain a quantitative 80 g / m 2 The paper tube base paper is coated with lignin rosin sizing liquid on the surface of the paper tube base paper with a coating machine. The coating machine speed is set to 50mm / s and the coating amount is 8g / m 2 , dried at 95℃, rolled into a roll, and obtained a compression-resistant recycled paper tube for packaging.

[0088] Comparative Example 3: This comparative example relates to a processing technology for a compression-resistant recycled paper tube for packaging. The difference from Example 1 is that the reinforcing agent is cellulose, specifically:

[0089] Step 1: Preparation of high molecular weight lignin

[0090] The lignin raw material was added to a 95% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, and then vacuum filtered to filter out the undissolved portion. Subsequently, the undissolved portion was added to a 70% ethanol aqueous solution, stirred at 400 rpm at room temperature for 2 hours, vacuum filtered, and the undissolved portion was filtered out again. The product was dried at 50°C to obtain high molecular weight lignin. The filtrate from the two filtrations was distilled to recover ethanol for reuse.

[0091] Step 2: Preparation of lignin surfactant

[0092] Dissolve 14.4g of sodium hydroxide in 60g of deionized water, stir evenly, add 4g of high molecular weight lignin, mix evenly, slowly add 20g of epichlorohydrin at 500rpm in a constant temperature water bath at 65°C and react for 5h. After the reaction is completed, adjust the pH to 7 with sodium dihydrogen phosphate, rinse with deionized water, filter, and dry to obtain epoxidized high molecular weight lignin. Dissolve 0.36g of sodium hydroxide in 30g of deionized water, stir evenly, add the obtained epoxidized high molecular weight lignin, slowly add 11g of triethylamine at 500rpm in a constant temperature water bath at 65°C and react for 4h. After the reaction is completed, adjust the pH to 2 with hydrochloric acid, wash with deionized water, filter, and dry to obtain a lignin surfactant.

[0093] Step 3: Prepare lignin rosin sizing solution

[0094] 20 g of lignin surfactant, 20 g of cationic polyacrylamide, and 10 g of nonionic polyacrylamide were added to 100 g of deionized water, and the mixture was stirred and dispersed at 80° C. and 500 rpm for 30 min to obtain a lignin emulsion. 20 g of rosin was heated and melted at 135° C. and 500 rpm, and the lignin emulsion was then dropped into the melted rosin solution. The rotation speed was adjusted to 2000 rpm, and 900 g of deionized water was added to form a lignin rosin glue emulsion. The lignin rosin glue emulsion was quickly cooled to room temperature with ice water, and then high-pressure homogenized for 5 min to obtain a lignin rosin sizing solution.

[0095] Step 4: Prepare the compression-resistant recycled paper tube for packaging

[0096] The collected waste paper was crushed, and after impurities were screened out, 20 g was weighed and added to 980 g of deionized water to soak for 24 hours. After soaking, the waste paper and the deionized water were transferred to a beater, and the waste paper was decomposed and beaten. The beating time was controlled to be 30 minutes and the beating speed was 8000 rpm. Then, the impurities were removed by a sieving instrument to obtain waste paper pulp. The waste paper pulp was mixed with 0.08 g of chitosan composite modifier and enhancer, stirred evenly, and then put on the screen for papermaking. It was shaped at 5 MPa and dried at 100 ° C to obtain a quantitative 80 g / m 2The paper tube base paper is coated with lignin rosin sizing liquid on the surface of the paper tube base paper with a coating machine. The coating machine speed is set to 50mm / s and the coating amount is 8g / m 2 , dried at 95℃, rolled into a roll, and obtained a compression-resistant recycled paper tube for packaging.

[0097] Detection experiment:

[0098] Compression-resistant recycled paper tubes for packaging were produced according to the processing techniques in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3, respectively.

[0099] Ring Crush Performance Test: In accordance with the "Determination of Ring Crush Strength of Paper and Paperboard" (GB / T2679.8-2016), samples were cut from compression-resistant recycled paper tubes for packaging and the ring crush index of the samples was tested using a ring crush strength tester (CT-300A). The sample size was 100mm x 15mm. Each paper tube was tested 10 times and the average value was taken.

[0100] Tensile performance test: According to "Paper and paperboard - Determination of tensile strength" (GB / T12914-2008), samples were cut from compression-resistant recycled paper tubes used for packaging. The tensile index of the samples was tested using a tensile strength tester (IMT-Tensile-02). The sample size was 100mm x 15mm. Each paper tube was tested 10 times, and the average value was taken.

[0101] Tear performance test: According to "Paper and paperboard - Determination of tear resistance" (GB / T 455-2002), samples were cut from compression-resistant recycled paper tubes used for packaging. The tear index of the samples was tested using a tear strength tester (IMT-201). The sample size was 65mm x 75mm. Each paper tube was tested 10 times, and the average value was taken.

[0102] Burst resistance test: In accordance with "Determination of the burst resistance of paper" (GB / T 1454-2002), samples were cut from compression-resistant recycled paper tubes for packaging and tested for their burst resistance using a tear strength tester (IMT-102). The sample size was 70mm x 70mm. Each paper tube was tested 10 times, and the average value was taken.

[0103]

[0104] Conclusion: The test data demonstrates that the ring crush index, tensile index, tear index, and burst resistance index of the compression-resistant recycled paper tube for packaging processed using the processing technology of Example 1 are all higher than those of the compression-resistant recycled paper tube for packaging processed using the processing technologies of Comparative Examples 1, 2, and 3. The processing technology provided by the present invention can produce recycled paper tubes with excellent ring crush performance, tensile strength, tear performance, and burst resistance, meeting the needs of the packaging industry.

[0105] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A process for producing a compression-resistant recycled paper tube for packaging, characterized by: Specifically: The collected waste paper is crushed, and after impurities are screened out, it is added into deionized water and soaked for 12 to 24 hours. After soaking, it is decomposed and pulped, and the pulping time is controlled to be 15 to 45 minutes, and the pulping speed is 5000 to 10000 rpm. Then the impurities are removed to obtain waste paper pulp, and the waste paper pulp is mixed with chitosan composite modification and reinforcement agent, stirred evenly, and then put on the net for papermaking. After shaping and drying, paper tube base paper is obtained, and lignin rosin sizing solution is coated on the surface of the paper tube base paper, dried, and rolled to obtain pressure-resistant recycled paper tube for packaging.

2. The processing technology of a compression-resistant recycled paper tube for packaging according to claim 1, characterized in that: The mass ratio of waste paper to chitosan composite modifier and enhancer is (90-120):(0.4-0.8).

3. The processing technology of the compression-resistant recycled paper tube for packaging according to claim 1, characterized in that: The preparation method of chitosan modified reinforcing agent is: Adding ethylene glycol diethyl ether diamine tetraacetic acid to deionized water, adjusting the pH to 12-13 with sodium hydroxide, and stirring uniformly to obtain an ethylene glycol diethyl ether diamine tetraacetic acid solution, adding sodium hydrogen tripolyphosphate to the solution, stirring uniformly, and heating at 60-70° C. for 18-24 hours. After the reaction is complete, adding nanocrystalline cellulose, followed by ultrasonic dispersion for 20-30 minutes to obtain a cellulose dispersion, heating the cellulose dispersion at 110-120° C. for 5-6 hours, filtering after the reaction is complete, and drying to obtain ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose. Acetic acid and deionized water are mixed and stirred evenly to obtain an acetic acid solution. Chitosan is added to the acetic acid solution and stirred evenly to fully dissolve to obtain a chitosan acetic acid solution. Ethylene glycol diethyl ether diamine tetraacetic acid-modified cellulose is mixed with deionized water and stirred evenly, and then the chitosan acetic acid solution is added. The mixture is stirred and reacted at 75-85° C. for 2-4 hours. After the reaction is completed, it is filtered and dried to obtain a chitosan composite modified enhancer.

4. The process for producing a compression-resistant recycled paper tube for packaging according to claim 3, characterized in that: The mass ratio of ethylene glycol diethyl ether diamine tetraacetic acid, sodium hydrogen tripolyphosphate and nanocrystalline cellulose is (4-6):(0.4-0.6):(1-10).

5. The process for producing a compression-resistant recycled paper tube for packaging according to claim 3, characterized in that: The mass ratio of acetic acid, chitosan and ethylene glycol diethyl ether diamine tetraacetic acid modified cellulose is (0.5-1):(5-10):(1-3).

6. The process for producing a compression-resistant recycled paper tube for packaging according to claim 1, characterized in that: The preparation method of lignin rosin glue sizing liquid is: A lignin surfactant, a cationic polyacrylamide, and a nonionic polyacrylamide are added to deionized water, and the mixture is stirred and dispersed at 70-80° C. and 500-700 rpm for 20-40 minutes to obtain a lignin emulsion. Rosin is heated and melted at 125-135° C. and 500-700 rpm. The lignin emulsion is then dripped into the melted rosin solution, the rotation speed is adjusted to 1500-2000 rpm, and deionized water is added to form a lignin rosin glue emulsion. The lignin rosin glue emulsion is quickly cooled to room temperature with ice water, and then high-pressure homogenized for 5-10 minutes to obtain a lignin rosin sizing solution.

7. The process for producing a compression-resistant recycled paper tube for packaging according to claim 6, characterized in that: The lignin rosin sizing solution comprises, by weight, 15 to 25 parts of lignin surfactant, 18 to 22 parts of cationic polyacrylamide, 8 to 12 parts of nonionic polyacrylamide, and 15 to 25 parts of rosin.

8. The process for producing a compression-resistant recycled paper tube for packaging according to claim 6, characterized in that: The preparation method of lignin surfactant is as follows: The lignin raw material is added to a 95% ethanol aqueous solution, stirred at 300-500 rpm at room temperature for 1-3 hours, and then vacuum filtered to filter out the undissolved portion. Subsequently, the undissolved portion is added to a 70% ethanol aqueous solution, stirred at 300-500 rpm at room temperature for 1-3 hours, vacuum filtered, and the undissolved portion is filtered out again. The product is dried at 50-60° C. to obtain high molecular weight lignin, and the filtrate from the two filtrations is distilled to recover ethanol for reuse; Sodium hydroxide is dissolved in deionized water, stirred evenly, and then high molecular weight lignin is added. After mixing evenly, epichlorohydrin is added in a constant temperature water bath at 60-70°C and 300-500 rpm and reacted for 3-5 hours. After the reaction is completed, the pH is adjusted to 7-8 with sodium dihydrogen phosphate, and the mixture is rinsed with deionized water, filtered, and dried to obtain epoxidized high molecular weight lignin. Sodium hydroxide is dissolved in deionized water, stirred evenly, and then the obtained epoxidized high molecular weight lignin is added. Triethylamine is slowly added in a constant temperature water bath at 60-70°C and 300-500 rpm and reacted for 3-5 hours. After the reaction is completed, the pH is adjusted to 2-3 with hydrochloric acid, and the mixture is washed with deionized water, filtered, and dried to obtain a lignin surfactant.

9. The process for producing a compression-resistant recycled paper tube for packaging according to claim 8, characterized in that: The mass ratio of high molecular weight lignin, epichlorohydrin and triethylamine is (2-6):(15-25):(5-15).

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