High-strength corrugating base paper prepared from domestic waste paper and preparation method of high-strength corrugating base paper

Abstract

The invention discloses high-strength corrugating base paper prepared from domestic waste paper and a preparation method of the high-strength corrugating base paper, and relates to the technical field of corrugating base paper preparation. The preparation method of the high-strength corrugating base paper comprises the steps of regenerated fiber pulp preparation, paper making raw pulp preparation, pulp flushing dilution, corrugating base paper making and the like. Wherein the domestic waste paper and the plant fibers are mixed in proportion, then the mixture is mixed with a finishing aid for disc milling dissociation to prepare regenerated fiber pulp, and then the regenerated fiber pulp is treated by biological compound enzyme and mixed starch to prepare the paper-making raw pulp, so that the comprehensive performance of the fibers in the paper-making raw pulp can be effectively improved through the treatment steps, and the paper-making raw pulp can be recycled. Therefore, the mechanical strength of the corrugating base paper produced from the domestic waste paper can be improved, and the dependence of the production of the high-strength corrugating base paper on foreign high-quality waste paper and chemical enhancers is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of corrugated paper preparation, and in particular to high-strength corrugated paper prepared from domestic waste paper and a preparation method thereof. Background Art

[0002] Corrugated paper is one of the important materials for producing corrugated board. Generally, corrugated paper not only requires good fiber bonding strength, flat surface, good tightness and stiffness, but also needs to have a certain elasticity to ensure that the finished carton has good shock resistance and pressure resistance. Corrugated paper can be divided into three grades according to the quality of the paper: superior, first-class and qualified.

[0004] In order to meet the requirements of high-end customers for the strength of corrugated paper, the current domestic production of high-strength corrugated paper will increase the strength of the paper by adding more chemical enhancers in the pulp pool to make up for the shortage of domestic waste paper fibers. However, when the use of chemical enhancers increases, it not only increases the production cost, but also increases the pollution load of wastewater, and the cost of wastewater treatment also increases accordingly. Therefore, by improving the fibers extracted from domestic waste paper, improving the quality of corrugated paper produced from domestic waste paper, and reducing the dependence of high-strength corrugated paper on foreign high-quality waste paper and chemical enhancers, it is of great significance to the production of the domestic corrugated paper industry. Summary of the invention

[0005] In order to improve the quality of corrugated paper produced from domestic waste paper and reduce the dependence of the production of medium and high-end high-strength corrugated paper on foreign high-quality waste paper and chemical enhancers, the present application provides a high-strength corrugated paper prepared from domestic waste paper and a preparation method thereof.

[0006] In the first aspect, the present application provides a method for preparing high-strength corrugated base paper using domestic waste paper, which adopts the following technical solution: A method for preparing high-strength corrugated base paper using domestic waste paper comprises the following steps: S1. Preparation of recycled fiber slurry: firstly, domestic waste paper and plant fiber are mixed and crushed in a weight ratio of (7-8): (2-3) to obtain mixed chopped fibers, and after the mixed chopped fibers are firstly de-slaged and washed, a first portion of water and a finishing agent are added to perform preliminary mixing to obtain a first mixed solution, and then the first mixed solution is subjected to disc grinding dissociation, second de-slaged and washed and cooled, and a second portion of water is added again to stir and dilute to a fiber content of 15wt%-20wt% to obtain recycled fiber slurry; S2, preparation of papermaking stock: taking the regenerated fiber slurry obtained in step S1, adding a biocomposite enzyme to perform enzymolysis treatment, and then adding mixed starch and mixing well to obtain papermaking stock; S3, pulping and dilution: the papermaking pulp obtained in step S2 is mixed with water or concentrated white water to obtain a second mixed liquid, and the second mixed liquid is used for the third deslagging, degassing and screening, and finally the papermaking pulp is further diluted with concentrated white water to a fiber content of 0.8wt%-1wt% to obtain a diluted pulp; S4, corrugated base paper making: spraying the diluted slurry obtained in step S3 onto a mesh surface, and then sequentially performing dehydration, forming, extrusion, and drying to obtain high-strength corrugated base paper; The concentrated white water in step S3 is the water naturally removed from the diluted slurry on the net by gravity in step S4.

[0007] By adopting the above technical scheme, mixing plant fibers with domestic waste paper, using finishing additives to prepare recycled fiber pulp, and using bio-complex enzymes and mixed starch to prepare papermaking pulp and other process steps, the comprehensive properties of the fibers in the papermaking pulp can be effectively improved, which is beneficial to improving the mechanical strength of corrugated paper and improving the quality of corrugated paper produced from domestic waste paper.

[0008] Optionally, in step S1, the preliminary mixing needs to be heated to 65-70° C. and stirred for 10-15 minutes; the mixing ratio of the first part of water to the mixed chopped fibers is 1:1; the amount of the finishing aid added accounts for 1%-2% of the weight of the mixed chopped fibers, and the specific finishing aid includes the following raw materials mixed and compounded in parts by weight: Amino polyether modified silicone oil: 30-40 parts; Sodium polyacrylate: 20-25 parts; Carboxymethyl cellulose: 15-20 parts; Sodium hydroxide: 10-15 parts; Sodium dodecyl sulfate: 6-12 parts; Silane coupling agent: 3-4 parts; The amino polyether modified silicone oil is prepared by chemically reacting polydimethylmethylhydrogensiloxane as a silicon source with allyl epoxy polyether and p-phenylenediamine, and the silane coupling agent is at least one of silane coupling agent KH-550 and silane coupling agent KH-560.

[0009] By adopting the above technical scheme, under the finishing of the finishing aid mainly composed of amino polyether modified silicone oil, the finishing aid can fully combine with the fiber surface during disc grinding and dissociation to form a lubricating film, which can not only reduce the friction between fibers, reduce the breakage of fibers during the dissociation process, and increase the content of medium and long fibers, but also give the fibers good flexibility and dispersibility, which is beneficial to improve the mechanical strength of corrugated paper, and thus improve the quality of corrugated paper produced from domestic waste paper.

[0010] Optionally, the preparation method of the amino polyether modified silicone oil comprises the following steps: A1. Preliminarily mix terminal allyl epoxy polyether, polydimethylmethylhydrogensiloxane and isopropanol, introduce inert gas and continue stirring for 10-15 minutes, then heat to 85-93°C, add chloroplatinic acid, maintain the temperature for 4-5 hours, then maintain the temperature for vacuum removal of low-boiling substances, and cool to room temperature to obtain epoxy polyether modified silicone oil; A2. Add p-phenylenediamine and isopropanol to the epoxy polyether modified silicone oil obtained in step A1, heat to 78-85°C and continue stirring to react for 4-5 hours, maintain the temperature to vacuum remove low-boiling substances, and obtain amino polyether modified silicone oil.

[0011] By adopting the above technical scheme, the preparation method of amino polyether modified silicone oil is simple, which is conducive to large-scale industrial production.

[0012] Optionally, the silane coupling agent is specifically a compound of silane coupling agent KH-550 and silane coupling agent KH-560 in a weight ratio of 1:(2-3).

[0013] By adopting the above technical solution, when KH-550 and KH-560 are used in combination, a certain synergistic effect can be produced, which is beneficial to improving the finishing effect of the finishing auxiliary agent on the mixed chopped fibers and is beneficial to further improving the mechanical strength of the fibers.

[0014] Optionally, in step S2, the enzymatic hydrolysis treatment needs to control the temperature at 45-48°C and continuously stir the reaction for not less than 1 hour, wherein the added amount of the bio-composite enzyme is 0.1%-0.12% by weight of the regenerated fiber slurry, and the bio-composite enzyme includes a mixture of at least two of alkaline xylanase, cellulase, and laccase and glutamic acid.

[0015] By adopting the above technical solution and controlling the temperature within the range of 45-48°C, the biocomposite enzyme can be fully activated at a suitable temperature, thereby promoting the enzymatic hydrolysis of most of the lignin and hemicellulose in domestic waste paper fibers and plant fibers. By using the biocomposite enzyme to enzymatically hydrolyze the fibers in the regenerated fiber slurry, it can not only repair the keratinization of the fibers, but also promote the nano-crystallization of cellulose, making it easier for the fibers to be fibrillated during the pulping process, which is beneficial to improving the mechanical strength of the corrugated base paper after the papermaking pulp is formed.

[0016] Optionally, the biological complex enzyme is a mixture of alkaline xylanase, cellulase, laccase and glutamic acid, and the mixing weight ratio of the alkaline xylanase, the cellulase, the laccase and the glutamic acid is 1:1.5:(1-2):(5.5-6.5).

[0017] By adopting the above technical scheme, laccase can fully degrade the lignin on the fiber surface, and then cooperate with alkaline xylanase, cellulase and glutamic acid to enzymatically hydrolyze and reinforce the fiber, which can fully degrade most of the lignin and hemicellulose in domestic waste paper fibers and plant fibers, which is beneficial to further improve the effect of enzymatic treatment on recycled fiber pulp.

[0018] Optionally, in step S3, the added amount of the mixed starch is 0.2%-0.25% of the weight of the regenerated fiber slurry, and the mixed starch is a mixture of oxidized starch and cationic starch in a weight ratio of 1:(1-2).

[0019] By adopting the above technical scheme, oxidized starch and cationic starch are mixed in a weight ratio of 1: (1-2) to form a mixed starch, which can utilize the reinforcing effect of cationic starch to improve the dry strength of corrugated paper, thereby helping to improve the quality of corrugated paper produced from domestic waste paper.

[0020] Optionally, the mixed starch needs to be pre-gelatinized before adding, and the pre-gelatinization treatment includes the following steps: first, the mixed starch is added into water, and continuously stirred to prepare a starch suspension with a concentration of 10%, and then heated to 90-95°C by indirect steam, and the temperature is maintained and continuously stirred for 20-30 minutes to complete the pre-gelatinization treatment, and it needs to be stored at 60-65°C for future use.

[0021] By adopting the above technical scheme, the pregelatinized mixed starch can be more easily adsorbed on the fiber during slurry preparation, and the retention rate and water filtration rate of the mixed starch can be effectively improved, so that the bonding effect and reinforcement effect of the mixed starch on the fiber are improved, which is beneficial to further improve the mechanical strength of the corrugated base paper.

[0022] Optionally, in the step S1, the plant fiber may be selected from straw fiber or bagasse fiber.

[0023] By adopting the above technical scheme, not only can the longer native plant fibers be used to make up for the shortage of domestic waste paper and improve the mechanical strength of corrugated paper, but also the straw fibers and bagasse fibers are both waste by-products in agriculture, which can fully play the role of waste utilization and have certain environmental protection significance.

[0024] In a second aspect, the present application provides a high-strength corrugated base paper prepared using domestic waste paper.

[0025] In summary, the technical solution of this application has at least one of the following beneficial effects: 1. By mixing plant fibers with domestic waste paper, preparing recycled fiber pulp with finishing additives, and preparing papermaking pulp with biocomplex enzymes and mixed starch, etc., the comprehensive properties of fibers in papermaking pulp can be effectively improved, which is beneficial to improving the mechanical strength of corrugated paper and improving the quality of corrugated paper produced from domestic waste paper.

[0026] 2. By using finishing agents mainly composed of amino polyether modified silicone oil to finish the mixed chopped fibers, it can not only reduce the friction between fibers, reduce the breakage of fibers during the dissociation process, and increase the content of medium and long fibers, but also give the fibers good flexibility and dispersibility, which is beneficial to improve the mechanical strength of corrugated paper.

[0027] 3. By using a bio-composite enzyme prepared by mixing alkaline xylanase, cellulase, laccase and glutamic acid in a weight ratio of 1:1.5:(1-2):(5.5-6.5) to enzymatically treat the regenerated fiber pulp, it is not only beneficial to further repair the keratinization of the fiber, but also beneficial to promote the nano-crystallization of cellulose, making the fiber easier to be fibrillated during the pulping process, thereby helping to improve the mechanical strength of the corrugated base paper after the papermaking pulp is formed.

[0028] 4. By mixing oxidized starch and cationic starch in a weight ratio of 1: (1-2) to prepare mixed starch for pulping, the dry strength of corrugated paper can be improved by virtue of the reinforcing effect of cationic starch, thereby improving the quality of corrugated paper produced from domestic waste paper.

[0029] 5. By pre-gelatinizing the mixed starch before adding it, the retention rate and water filtration rate of the mixed starch can be effectively improved, and the bonding and reinforcement effects of the mixed starch on the fiber can be improved, which is beneficial to further improve the mechanical strength of the corrugated base paper. DETAILED DESCRIPTION

[0030] The present application is further described in detail below in combination with preparation examples, embodiments and comparative examples.

[0031] Preparation Example [Preparation Example 1-1] An amino-terminated polyether modified silicone oil is prepared by the following steps: A1. Mix terminal allyl epoxy polyether, polydimethylmethyl hydrogen siloxane and isopropanol, introduce nitrogen and continue stirring for 10 minutes, wherein the molar ratio of terminal allyl epoxy polyether to polydimethylmethyl hydrogen siloxane is 1.2:1, then heat to 93°C, add 0.001% chloroplatinic acid based on the weight of polydimethylmethyl hydrogen siloxane, maintain the temperature for reaction for 4 hours, maintain the temperature for vacuum removal of low boiling points for 30 minutes, and cool to room temperature to obtain epoxy polyether modified silicone oil; A2. Add p-phenylenediamine and isopropanol to the epoxy polyether modified silicone oil obtained in step A1, wherein the molar ratio of terminal allyl epoxy polyether to p-phenylenediamine is 1:1.2, heat to 85°C and continue stirring to react for 4 hours, then remove low boiling points in vacuo for 0.5 hours to obtain amino polyether modified silicone oil.

[0032] [Preparation Example 1-2] An amino-terminated polyether modified silicone oil is prepared by the following steps: A1. Mix terminal allyl epoxy polyether, polydimethylmethyl hydrogen siloxane and isopropanol, introduce nitrogen and continue stirring for 15 minutes, wherein the molar ratio of terminal allyl epoxy polyether to polydimethylmethyl hydrogen siloxane is 1.5:1, then heat to 85°C, add 0.001% chloroplatinic acid based on the weight of polydimethylmethyl hydrogen siloxane, maintain the temperature for reaction for 5 hours, maintain the temperature for vacuum removal of low boiling points for 30 minutes, and cool to room temperature to obtain epoxy polyether modified silicone oil; A2. Add p-phenylenediamine and isopropanol to the epoxy polyether modified silicone oil obtained in step A1, wherein the molar ratio of terminal allyl epoxy polyether to p-phenylenediamine is 1:1.5, heat to 78°C and continue stirring to react for 5 hours, then remove low-boiling products in vacuo for 30 minutes to obtain amino polyether modified silicone oil.

[0033] [Preparation Example 2-1] A finishing agent comprising the following raw materials: 0.3kg amino polyether modified silicone oil, 0.25kg sodium polyacrylate, 0.2kg carboxymethyl cellulose, 0.1kg sodium hydroxide, 0.12kg sodium dodecyl sulfate and 0.03kg silane coupling agent KH-560.

[0034] The amino polyether modified silicone oil is specifically selected from the amino polyether modified silicone oil prepared in [Preparation Example 1-1].

[0035] [Preparation Example 2-2] A finishing agent comprising the following raw materials: 0.4kg amino polyether modified silicone oil, 0.2kg sodium polyacrylate, 0.15kg carboxymethyl cellulose, 0.15kg sodium hydroxide, 0.06kg sodium dodecyl sulfate and 0.04kg silane coupling agent.

[0036] The amino polyether modified silicone oil is the amino polyether modified silicone oil prepared in [Preparation Example 1-2]. The silane coupling agent is a mixture of silane coupling agent KH-550 and silane coupling agent KH-560 in a weight ratio of 1:3, i.e., 0.01 kg of silane coupling agent KH-550 and 0.03 kg of silane coupling agent KH-560.

[0037] [Preparation Example 2-3] A finishing auxiliary agent, which differs from [Preparation Example 2-1] in that the silane coupling agent is different.

[0038] In this preparation example, the silane coupling agent was replaced by an equal amount of silane coupling agent KH-550.

[0039] [Preparation Example 2-4] A finishing auxiliary agent, which differs from [Preparation Example 2-1] in that the silane coupling agent is different.

[0040] In this preparation example, the silane coupling agent is specifically a mixture of silane coupling agent KH-550 and silane coupling agent KH-560 in a weight ratio of 1:2, namely, 0.01 kg of silane coupling agent KH-550 and 0.02 kg of silane coupling agent KH-560.

[0041] [Preparation Example 2-5] A finishing auxiliary agent, which differs from [Preparation Example 2-1] in that amino polyether modified silicone oil is not added.

[0042] In this preparation example, the amino polyether modified silicone oil is replaced by an equal amount of dimethyl silicone oil. Example

[0043] [Example 1] A method for preparing high-strength corrugated base paper using domestic waste paper comprises the following steps: S1. Preparation of recycled fiber slurry: First, 8 kg of domestic waste paper and 2 kg of plant fiber are mixed and crushed to obtain mixed chopped fibers. After the mixed chopped fibers are deslagging and washed for the first time, 10 kg of water and 0.1 kg of finishing aid are added, and the mixture is heated to 70°C and stirred for 10 minutes to obtain a first mixed solution. The first mixed solution is then subjected to disc grinding for dissociation, deslagging and washing and cooling for a second time, and water is added again and stirred to dilute to a solid content of 20 wt% to obtain recycled fiber slurry.

[0044] The plant fiber is straw fiber, specifically rice straw; the finishing aid is specifically the finishing aid prepared in [Preparation Example 2-1].

[0045] S2. Preparation of papermaking stock: 50 kg of the regenerated fiber pulp obtained in step S1 was taken, 50 g of the biocomplex enzyme was added, the temperature was controlled at 48° C. and stirring was continued for 1 hour, and then 100 g of mixed starch was added and mixed thoroughly to obtain papermaking stock.

[0046] The biocomplex enzyme is a mixture of alkaline xylanase, cellulase and glutamic acid in a weight ratio of 1:1.5:7.5, including 5g of alkaline xylanase, 7.5g of cellulase and 37.5g of glutamic acid. The mixed starch is a mixture of oxidized starch and cationic starch in a weight ratio of 1:1, including 50g of oxidized starch and 50g of cationic starch.

[0047] S3, pulping and dilution: the papermaking pulp obtained in step S2 is mixed with water or concentrated white water to obtain a second mixed liquid, and the second mixed liquid is used for the third deslagging, degassing and screening. Finally, the papermaking pulp is further diluted with concentrated white water to a solid content of 1wt% to obtain a diluted pulp.

[0048] S4, corrugated base paper making: spray the diluted slurry obtained in step S3 onto the mesh surface and then perform dehydration, forming, extrusion and drying in sequence to obtain high-strength corrugated base paper.

[0049] The concentrated white water in step S3 is the water naturally removed from the diluted slurry on the net by gravity in step S4.

[0050] A high-strength corrugated base paper prepared from domestic waste paper is prepared by the above-mentioned preparation method.

[0051] [Example 2] A method for preparing high-strength corrugated base paper using domestic waste paper comprises the following steps: S1. Preparation of recycled fiber slurry: First, 7 kg of domestic waste paper and 3 kg of plant fiber are mixed and crushed to obtain mixed chopped fibers. After the mixed chopped fibers are deslagging and washed for the first time, 10 kg of water and 0.2 kg of finishing aid are added, and the mixture is heated to 65 ° C and stirred for 15 minutes to obtain a first mixed solution. The first mixed solution is then subjected to disc grinding for dissociation, deslagging and washing and cooling for a second time, and water is added again and stirred to dilute to a solid content of 15 wt% to obtain recycled fiber slurry.

[0052] The plant fiber is specifically bagasse fiber; and the finishing auxiliary agent is specifically the finishing auxiliary agent prepared in [Preparation Example 2-2].

[0053] S2. Preparation of papermaking stock: 50 kg of the regenerated fiber pulp obtained in step S1 was taken, 60 g of the biocomplex enzyme was added, the temperature was controlled at 43° C. and stirred for 2 h, and then 125 g of mixed starch was added and mixed thoroughly to obtain papermaking stock.

[0054] The biocomplex enzyme is a mixture of cellulase, laccase and glutamic acid in a weight ratio of 2:1:7, including 10g of cellulase, 5g of laccase and 35g of glutamic acid. Cellulase and glutamic acid are mixed in a weight ratio of 2:8, including 10g of cellulase and 40g of glutamic acid. The mixed starch is a mixture of oxidized starch and cationic starch in a weight ratio of 1:1.5, including 50g of oxidized starch and 75g of cationic starch.

[0055] S3, pulping and dilution: the papermaking pulp obtained in step S2 is mixed with water or concentrated white water to obtain a second mixed liquid, and the second mixed liquid is used for the third deslagging, degassing and screening. Finally, the papermaking pulp is further diluted with concentrated white water to a solid content of 0.7wt% to obtain a diluted pulp.

[0056] S4, corrugated base paper making: spray the diluted slurry obtained in step S3 onto the mesh surface and then perform dehydration, forming, extrusion and drying in sequence to obtain high-strength corrugated base paper.

[0057] The concentrated white water in step S3 is the water naturally removed from the diluted slurry on the net by gravity in step S4.

[0058] A high-strength corrugated base paper prepared from domestic waste paper is prepared by the above-mentioned preparation method.

[0059] [Example 3] A method for preparing high-strength corrugated paper using domestic waste paper, which differs from [Example 1] in that the finishing aid used in step S1 is different.

[0060] In this embodiment, the finishing auxiliary agent is specifically selected from the finishing auxiliary agent prepared in [Preparation Example 2-3].

[0061] A high-strength corrugated base paper prepared from domestic waste paper is prepared by the above-mentioned preparation method.

[0062] [Example 4] A method for preparing high-strength corrugated paper using domestic waste paper, which differs from [Example 1] in that the finishing aid used in step S1 is different.

[0063] In this embodiment, the finishing auxiliary agent is specifically selected from the finishing auxiliary agent prepared in [Preparation Example 2-4].

[0064] A high-strength corrugated base paper prepared from domestic waste paper is prepared by the above-mentioned preparation method.

[0065] [Example 5] A method for preparing high-strength corrugated paper using domestic waste paper, which differs from [Example 4] in that the biological complex enzyme used in step S2 is different.

[0066] In this embodiment, the biological composite enzyme is specifically alkaline xylanase, cellulase, laccase and glutamic acid mixed in a weight ratio of 1:1.5:1:6.5, namely, including 5g alkaline xylanase, 7.5g cellulase, 5g laccase and 32.5g glutamic acid.

[0067] A high-strength corrugated base paper prepared from domestic waste paper is prepared by the above-mentioned preparation method.

[0068] [Example 6] A method for preparing high-strength corrugated paper using domestic waste paper, which differs from [Example 4] in that the biological complex enzyme used in step S2 is different.

[0069] In this embodiment, the biological composite enzyme is specifically alkaline xylanase, cellulase, laccase and glutamic acid mixed in a weight ratio of 1:1.5:2:5.5, namely, 5g alkaline xylanase, 7.5g cellulase, 10g laccase and 27.5g glutamic acid.

[0070] A high-strength corrugated base paper prepared from domestic waste paper is prepared by the above-mentioned preparation method.

[0071] [Example 7] A method for preparing high-strength corrugated paper using domestic waste paper, which differs from [Example 5] in that the mixed starch used in step S2 needs to be pre-gelatinized before addition.

[0072] Wherein, the pregelatinization treatment of the mixed starch comprises the following steps: First, add the mixed starch into water, keep stirring and prepare a starch suspension with a concentration of 10%, then heat it to 90°C through indirect steam, maintain the temperature and keep stirring for 30 minutes to complete the pre-gelatinization of the mixed starch. Note that it needs to be stored at 60-65°C for future use.

[0073] A high-strength corrugated base paper prepared from domestic waste paper is prepared by the above-mentioned preparation method.

[0074] Comparative Example [Comparative Example 1] A method for preparing corrugated paper, which differs from [Example 1] in that plant fiber is not added in step S1, and the plant fiber is replaced by domestic waste paper in equal amount.

[0075] A corrugated base paper is prepared by the above-mentioned preparation method.

[0076] [Comparative Example 2] A method for preparing corrugated paper, which differs from [Example 1] in that the finishing aid used in step S1 is different.

[0077] In this comparative example, the finishing auxiliary agent is specifically selected from the finishing auxiliary agent prepared in [Preparation Example 2-5].

[0078] A corrugated base paper is prepared by the above-mentioned preparation method.

[0079] [Comparative Example 3] A method for preparing corrugated paper, which differs from [Example 1] in that no biological complex enzyme is added in step S2, and no enzymatic hydrolysis is performed.

[0080] A corrugated base paper is prepared by the above-mentioned preparation method.

[0081] [Comparative Example 4] A method for preparing corrugated paper, which differs from [Example 1] in that in step S2, no mixed starch is added, and an equal amount of the mixed starch is replaced by oxidized starch.

[0082] A corrugated base paper is prepared by the above-mentioned preparation method.

[0083] Performance test data Preparation of the sample to be tested: The corresponding corrugated base paper was produced according to the preparation method provided in the embodiment and the comparative example, wherein the papermaking basis weight of the corrugated base paper was controlled at 90 g / m 2 , and then cut to the corresponding size according to different detections.

[0084] 1. Transverse ring crush index: The transverse ring crush strength of the sample to be tested was tested with reference to "GB / T 2679.8-2016 Determination of Ring Compression Strength of Paper and Paperboard", and the transverse ring crush strength index (N·m / g) of the sample to be tested obtained in each embodiment and comparative example was recorded after calculation.

[0085] 2. Determination of longitudinal breaking length: refer to "GB / T 12914-2018 Determination of tensile strength of paper and paperboard - Constant tension method (20 mm / min)" for detection, and record the longitudinal breaking length (km) of the samples to be tested prepared in each embodiment and comparative example.

[0086] 3. Burst index: Refer to GB / T 454-2002 Determination of burst strength of paper to test the sample, and record the burst index (kPa·m 2 / g).

[0087] Combining Examples 1-2 with Comparative Examples 1-4 and the data in Table 1, it can be seen that under the premise that the quantitative amount of the prepared corrugated base paper is the same, by adding plant fibers to mix with domestic waste paper, preparing recycled fiber slurry using finishing aids, and preparing papermaking pulp using biocomposite enzymes and mixed starch, etc., the transverse ring crush strength, longitudinal breaking length and bursting strength of the corrugated base paper can be effectively improved, which is conducive to improving the quality of the corrugated base paper produced from domestic waste paper. In addition, through the preparation method disclosed in Example 1, not only is it unnecessary to add foreign high-quality waste paper or too much chemical enhancer to make up for the deficiency of domestic waste paper fiber, but the added plant fiber can be selected from waste straw fiber or bagasse fiber in agriculture, which has certain environmental protection significance.

[0088] Combining Example 1 and Comparative Example 2 and the data in Table 1, it can be seen that when amino polyether modified silicone oil is used in the finishing agent to finish the fiber, the longitudinal fracture degree and burst resistance of the produced corrugated base paper are significantly improved compared with the traditional use of dimethyl silicone oil, which means that the tensile strength of the corrugated base paper is high. This may be because the amino polyether modified silicone oil chain segment contains not only amino functional groups, but also polyether chain segments and benzene rings. This allows the amino polyether modified silicone oil to be combined with other raw materials of the finishing agent. Not only can it fully combine with the fiber surface during disc grinding dissociation and form a lubricating film, thereby reducing the friction between fibers and reducing fiber breakage during the dissociation process, increasing the content of medium and long fibers, but it can also give the fiber good flexibility, thereby improving the mechanical strength of the fiber.

[0089] Combining Example 1 with Example 3-4 and the data in Table 1, it can be seen that when the silane coupling agent in the finishing aid is specifically selected from silane coupling agent KH-550 and silane coupling agent KH-560 and mixed in a weight ratio of 1:1, the mechanical strength of the obtained corrugated base paper is improved compared to when silane coupling agent KH-550 or silane coupling agent KH-560 is used alone. This may be because when KH-550 and KH-560 are used in combination, a synergistic effect is produced for the fiber system and finishing aid system of the present application, thereby improving the finishing effect of the finishing aid on the mixed chopped fibers and further improving the mechanical strength of the fibers.

[0090] Combining Example 1 with Comparative Example 3 and the data in Table 1, it can be seen that when the regenerated fiber pulp is enzymatically treated with a biocomposite enzyme before preparing the papermaking stock, the transverse ring crush strength, longitudinal breaking length and bursting strength of the corrugated base paper can be effectively improved, which is beneficial to improving the quality of the corrugated base paper produced from domestic waste paper. At the same time, in combination with Examples 4-6 and the data in Table 1, it can be seen that when the biocomposite enzyme uses a variety of alkaline xylanase, cellulase, laccase and glutamic acid mixed, the enzymatic treatment has a better strengthening effect on the corrugated base paper. This may be because the fibers in the domestic waste paper repeatedly undergo the swelling-drying process, causing the fibers to keratinize, resulting in a decrease in the fiber swelling ability and softness, and the enzymatic treatment of the biocomposite enzyme can degrade most of the lignin and hemicellulose in the domestic waste paper fibers and plant fibers, which can not only repair the keratinization of the fibers, but also promote the nano-ization of cellulose, making the fibers easier to separate and broom during the pulping process, and thus helping to improve the mechanical strength of the corrugated base paper after papermaking. However, as the proportion of laccase in the bio-composite enzyme increases and the proportion of glutamic acid decreases, the strengthening effect of enzymatic treatment on corrugated paper will decrease slightly. Therefore, when alkaline xylanase, cellulase, laccase and glutamic acid in the bio-composite enzyme are mixed in a weight ratio of 1:1.5:(1-2):(5.5-6.5), the comprehensive mechanical strength of the corrugated paper is better.

[0091] Combining Example 1 with Comparative Example 4 and the data in Table 1, it can be seen that by using cationic starch instead of partially oxidized starch, the mechanical strength of corrugated base paper can be effectively improved. In addition, combining Example 5 and Example 7 and the data in Table 1, it can be seen that when using a mixed starch formed by compounding oxidized starch and cationic starch to prepare the fiber, the preparation process of pre-gelatinizing the mixed starch in advance can improve the partial mechanical strength of the corrugated base paper to a certain extent compared to the preparation process of directly adding the mixed starch to the slurry. This may be because after the mixed starch is pre-gelatinized, the oxidized starch and cationic starch can be more easily adsorbed on the fiber, improving the retention rate and water filtration rate of the mixed starch, so that the bonding effect and reinforcement effect of the mixed starch on the fiber are improved, so the partial mechanical strength of the corrugated base paper can be further improved.

[0092] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing high-strength corrugated paper using domestic waste paper, characterized in that: The following steps are involved: S1. Preparation of recycled fiber slurry: firstly, domestic waste paper and plant fiber are mixed and crushed in a weight ratio of (7-8): (2-3) to obtain mixed chopped fibers; after the mixed chopped fibers are first deslagging and washed, a first portion of water and a finishing agent are added to perform preliminary mixing to obtain a first mixed solution; then, the first mixed solution is subjected to disc grinding for dissociation, second deslagging and washing and cooling; and a second portion of water is added again to stir and dilute the mixture to a fiber content of 15wt%-20wt% to obtain recycled fiber slurry; S2, preparation of papermaking stock: taking the regenerated fiber slurry obtained in step S1, adding a biocomposite enzyme to perform enzymolysis treatment, and then adding mixed starch and mixing well to obtain papermaking stock; S3, pulping and dilution: the papermaking pulp obtained in step S2 is mixed with water or concentrated white water to obtain a second mixed liquid, and the second mixed liquid is used for the third deslagging, degassing and screening, and finally the papermaking pulp is further diluted with concentrated white water to a fiber content of 0.8wt%-1wt% to obtain a diluted pulp; S4, corrugated base paper making: spraying the diluted slurry obtained in step S3 onto a mesh surface, and then sequentially performing dehydration, forming, extrusion, and drying to obtain high-strength corrugated base paper; The concentrated white water in step S3 is the water naturally removed from the diluted slurry on the net by gravity in step S4.

2. The method for preparing high-strength corrugated paper using domestic waste paper according to claim 1, characterized in that: In the step S1, the preliminary mixing needs to be heated to 65-70° C. and stirred for 10-15 minutes; the mixing ratio of the first part of water to the mixed chopped fibers is 1:1; the amount of the finishing aid added accounts for 1%-2% of the weight of the mixed chopped fibers, and the specific finishing aid includes the following raw materials mixed and compounded in parts by weight: Amino polyether modified silicone oil: 30-40 parts; Sodium polyacrylate: 20-25 parts; Carboxymethyl cellulose: 15-20 parts; Sodium hydroxide: 10-15 parts; Sodium dodecyl sulfate: 6-12 parts; Silane coupling agent: 3-4 parts; The amino polyether modified silicone oil is prepared by chemically reacting polydimethylmethylhydrogensiloxane as a silicon source with allyl epoxy polyether and p-phenylenediamine, and the silane coupling agent is at least one of silane coupling agent KH-550 and silane coupling agent KH-560.

3. The method for preparing high-strength corrugated paper using domestic waste paper according to claim 2, characterized in that: The preparation method of the amino polyether modified silicone oil comprises the following steps: A1. Preliminarily mix terminal allyl epoxy polyether, polydimethylmethylhydrogensiloxane and isopropanol, introduce inert gas and continue stirring for 10-15 minutes, then heat to 85-93°C, add chloroplatinic acid, maintain the temperature for 4-5 hours, then maintain the temperature for vacuum removal of low-boiling substances, and cool to room temperature to obtain epoxy polyether modified silicone oil; A2. Add p-phenylenediamine and isopropanol to the epoxy polyether modified silicone oil obtained in step A1, heat to 78-85°C and continue stirring to react for 4-5 hours, maintain the temperature to vacuum remove low-boiling substances, and obtain amino polyether modified silicone oil.

4. The method for preparing high-strength corrugated paper using domestic waste paper according to claim 2, characterized in that: The silane coupling agent is specifically prepared by compounding silane coupling agent KH-550 and silane coupling agent KH-560 in a weight ratio of 1:(2-3).

5. The method for preparing high-strength corrugated paper using domestic waste paper according to claim 1, characterized in that: In step S2, the enzymatic hydrolysis treatment needs to control the temperature at 45-48°C and continue to stir the reaction for not less than 1 hour, wherein the added amount of the bio-composite enzyme is 0.1%-0.12% by weight of the regenerated fiber slurry, and the bio-composite enzyme includes a mixture of at least two of alkaline xylanase, cellulase, and laccase and glutamic acid.

6. The method for preparing high-strength corrugated paper using domestic waste paper according to claim 5, characterized in that: The biological composite enzyme is a mixture of alkaline xylanase, cellulase, laccase and glutamic acid, and the mixing weight ratio of the alkaline xylanase, the cellulase, the laccase and the glutamic acid is 1:1.5:(1-2):(5.5-6.5).

7. The method for preparing high-strength corrugated paper using domestic waste paper according to claim 1, characterized in that: In step S3, the added amount of the mixed starch is 0.2%-0.25% of the weight of the regenerated fiber slurry, and the mixed starch is a mixture of oxidized starch and cationic starch in a weight ratio of 1: (1-2).

8. The method for preparing high-strength corrugated paper using domestic waste paper according to claim 7, characterized in that: The mixed starch needs to be pre-gelatinized before adding, and the pre-gelatinization process includes the following steps: First, add the mixed starch into water and keep stirring to prepare a starch suspension with a concentration of 10%, then heat to 90-95°C by indirect steam, maintain the temperature and keep stirring for 20-30 minutes to complete the pre-gelatinization treatment, and store at 60-65°C for future use.

9. The method for preparing high-strength corrugated paper using domestic waste paper according to claim 1, characterized in that: In the step S1, the plant fiber may be selected from straw fiber or bagasse fiber.

10. A high-strength corrugated base paper prepared by the method for preparing high-strength corrugated base paper using domestic waste paper as described in any one of claims 1 to 9.

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