Enzymatic banana cauloid fiber bamboo pulp paper with high mechanical property and preparation method of enzymatic banana cauloid fiber bamboo pulp paper

Abstract

The invention relates to enzymatic banana cauloid fiber bamboo pulp paper with high mechanical performance and a preparation method of the enzymatic banana cauloid fiber bamboo pulp paper. The banana cauloid is used as a raw material, a specific method is adopted to treat the banana cauloid, then the banana cauloid pulp is prepared through the steps of enzyme treatment, alkali treatment, washing, bleaching and the like, and the banana cauloid fiber and the bamboo pulp fiber are scientifically proportioned to replace part of the bamboo pulp fiber, so that the mechanical property of the pure bamboo pulp paper is improved, and the quality of the pure bamboo pulp paper is improved. The bamboo pulp paper with excellent performance is developed while the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of bamboo material pulping and papermaking, and particularly relates to an enzymatic banana pseudostem fiber bamboo pulp paper with high mechanical properties and a preparation method thereof. BACKGROUND

[0002] Bananas are a large crop with great economic value worldwide, and are planted on a large scale in about 136 countries. As the second largest banana producer in the world, China's planting area reached 320,000 hectares in 2023, with a total output of over 11.7 million tons. The industry system has matured. However, after harvesting, about 60% of the plant remains in the form of stems (commonly known as banana pseudostems), leaves and other agricultural waste. At present, such waste is mostly disposed of in a rough manner by field composting or direct burning, which not only causes valuable agricultural resources to be wasted, but also can cause air pollution and deterioration of soil physical and chemical properties, which is contrary to the current green, low-carbon and circular development industry orientation. How to achieve efficient resource utilization of banana pseudostem waste has become a key bottleneck restricting the high-quality development of the banana industry.

[0003] Studies have shown that banana pseudostems are rich in cellulose, hemicellulose, lignin, pectin and other components. Banana pseudostem fibers extracted therefrom have advantages such as high mechanical strength, large aspect ratio, good flexibility, low density, biodegradability and low cost, and have shown great application potential in the papermaking field, providing an important direction for the resource utilization of the above-mentioned waste. However, banana pseudostem fibers have similar properties to bast fibers and have a high content of gum, which makes it difficult to achieve good binding between fibers when used alone in papermaking, leading to loose paper structure and insufficient key mechanical properties such as burst strength and tear resistance, making it difficult to meet the actual application requirements. At the same time, single banana pseudostem fiber papermaking also has problems such as seasonal fluctuations in raw material supply and poor batch adaptability after fiber purification, further limiting its large-scale papermaking application. Therefore, optimizing the papermaking performance of banana pseudostem fibers by raw material matching has become a key breakthrough for their conversion into high-value paper products.

[0004] Bamboo, as a fast-growing type of grass, is a renewable plant and a traditional high-quality raw material in the field of pulping and papermaking. The bamboo pulp fiber prepared therefrom has a length between that of coniferous wood fiber and broadleaf wood fiber, and has strong fiber interweaving ability, which can significantly improve the structural stability and mechanical strength of the paper product, effectively making up for the performance shortcomings of single banana pseudostem fiber papermaking. In addition, the supply of bamboo raw materials is relatively stable, and the harvesting and processing technology is mature. When used in combination with banana pseudostem waste, it can balance the seasonal differences in raw material supply and reduce the overall raw material cost through reasonable matching - replacing part of the bamboo pulp fiber with low-cost banana pseudostem fiber, while controlling production costs, and achieving optimization and upgrading of the mechanical properties of the paper product by taking advantage of the complementary properties of the two types of fibers.

[0005] In summary, the low cost and excellent mechanical properties of banana pseudo-stem fibers provide the possibility for innovation of papermaking raw materials, but the performance limitations and supply problems of single application need to be solved; the addition of bamboo can not only improve the mechanical strength of paper products through fiber performance complementation, but also optimize the supply structure of raw materials and control production costs, which is a necessary choice to realize the resource utilization of banana pseudo-stem waste and the development of high-quality paper products. Based on this, it has important practical significance and industrial application value to develop an enzymatic banana pseudo-stem fiber bamboo pulp paper with high mechanical properties and a preparation method thereof, which can promote the comprehensive utilization of agricultural waste and promote the quality and efficiency of the paper industry. SUMMARY

[0006] The present application aims at the problems of poor strength and the like of bamboo pulp paper in the prior art, so that the banana pseudo-stem is treated by a specific method, and then subjected to enzyme treatment, alkali treatment, washing, bleaching and the like to prepare banana pseudo-stem pulp, so that the preparation of bamboo pulp paper can enhance the strength of bamboo pulp paper to a certain extent.

[0007] In order to achieve the above-mentioned purpose, the present application is realized by the following means:

[0008] The present application provides a preparation method of an enzymatic banana pseudo-stem fiber bamboo pulp paper with high mechanical properties, comprising the following steps:

[0009] (1) The banana pseudo-stem is harvested, washed, cut into pieces, dried, subjected to enzyme treatment, alkali treatment, washed, bleached and washed to neutral, so as to prepare banana pseudo-stem pulp;

[0010] (2) The banana pseudo-stem pulp prepared in step (1) and bamboo pulp are respectively beaten and matched according to the proportion, and a dispersing agent is added, so as to prepare bamboo pulp paper by defibrating and sheeting and drying.

[0011] Preferably, the angle between the cutting surface and the ground during harvesting of the banana pseudo-stem is between 30°-60°, and the harvested banana pseudo-stem must be treated within 24 hours after harvesting.

[0012] Preferably, the washing, cutting and drying treatment process in step (1) is that the harvested banana pseudo-stem is washed by high-pressure water, cut into uniform pieces with a length of 3-5 cm, and dried in a 75-85℃ drying oven until the water content is 8-12% for standby.

[0013] Preferably, the enzyme treatment process in step (1) is:

[0014] a. Pretreatment immersion: the dried banana pseudo-stem segments are immersed in 40-50℃ water containing a surfactant according to a bath ratio of 1:8-12 for 10-30 min;

[0015] b. Stepwise synergistic enzymatic hydrolysis: after draining, replenish the complex biological enzyme liquid, adjust the bath ratio to 1:15-25, and perform the enzymatic hydrolysis reaction;

[0016] c. Post-treatment: after the enzymatic hydrolysis is completed, rapidly increase the temperature to above 95℃ for 15-25 min to inactivate the enzyme, and then wash to neutral.

[0017] Preferably, the surfactant in step a is selected from one or more of rhamnolipid, sucrose ester, and polysorbate-80.

[0018] Preferably, the surfactant is used in an amount of 0.05-0.3wt% of the mass of the complex biological enzyme liquid.

[0019] Preferably, the complex biological enzyme liquid in step b includes endo-cellulase, xylanase, and lytic polysaccharide monooxygenase; more preferably, the complex biological enzyme liquid includes endo-cellulase, xylanase, and lytic polysaccharide monooxygenase, and the enzyme activity ratio of endo-cellulase, xylanase, and lytic polysaccharide monooxygenase is 1-3:2-4:1, and the total enzyme activity addition amount is 15-40 U / g.

[0020] Preferably, the enzymatic hydrolysis reaction in step b is specifically: reacting at pH 5.0-6.0 and a temperature of 50-58℃ for 60-120 min; and then adjusting the pH to 4.5-5.0 and continuing to react at a temperature of 45-50℃ for 60-120 min.

[0021] Preferably, the alkali treatment process in step (1) is specifically: placing the enzyme-treated banana pseudostem raw material (absolute dry) in a digester, setting the bath ratio to 1:(15-20), the NaOH amount to 18-22% (based on the mass of the absolute dry raw material), cooking at 150℃-165℃ for 50-70 min, cooling to room temperature after the reaction is completed, and washing the pulp to neutral.

[0022] Preferably, the bleaching process in step (1) is specifically: based on the mass of the absolute dry pulp, the pulp concentration is 8-12wt%, the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 3.5-45%, 0.3-1.2%, 0.02-0.05%, 1.2-1.5%, and 1.2-1.5%, respectively, reacting in a water bath at 75-85℃ for 90-110 min, and washing the banana pseudostem fibers to neutral after the bleaching is completed.

[0023] Preferably, the beating in step (2) is beating the banana pseudostem to 28-45°SR and beating the bamboo pulp to 32-38°SR.

[0024] As preferably, the proportioning in step (2) is carried out according to the weight ratio of banana pseudo stem pulp: bamboo pulp = 1: (2-4).

[0025] As preferably, the dispersing agent in step (2) is polyethylene oxide, and the adding amount is 0.05-0.15wt% of the total dry mass of the pulp.

[0026] As preferably, the defibrating in step (2) is 8000-12000r.

[0027] As preferably, the paper drying temperature in step (2) is 90℃, and the time is 10min.

[0028] The second aspect of the present application provides a high mechanical performance enzymatic banana pseudo stem fiber bamboo pulp paper prepared according to the above preparation method.

[0029] The present application has the following beneficial effects relative to the prior art:

[0030] Through a large number of researches, the present application adopts a specific method to treat banana pseudo stem, and then carries out enzyme treatment, alkali treatment, washing, bleaching and other steps to prepare banana pseudo stem pulp, so that the preparation of bamboo pulp paper can enhance the strength of bamboo pulp paper to a certain extent.

[0031] The present application can make the banana pseudo stem fiber have better fiber performance by treating the banana pseudo stem, which can enhance the strength of bamboo pulp paper to a certain extent and improve the performance of bamboo pulp paper. In addition, the present application uses banana pseudo stem as raw material, which is low in cost, realizes the comprehensive utilization of agricultural waste, reduces environmental pollution, and has great market prospect and social significance. DETAILED DESCRIPTION

[0032] To make the purpose, technical scheme and effect of the present application more clear and explicit, the present application is further described in detail below with reference to examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0033] Blank example

[0034] The preparation method of bamboo pulp paper without banana pseudo stem fiber comprises the following steps:

[0035] The commercially available bamboo pulp (pulp concentration is 10wt%) is treated by a PFI beater to obtain bamboo pulp with a beating degree of 35°SR, 0.1wt% polyethylene oxide is added as a dispersing agent, and the fiber is defibrated in a fiber defibrator for 8000r, a Keeser automatic paper machine is used to prepare paper with a basis weight of 40g / m 2 , the paper drying temperature is 90℃, and the time is 10min.

[0036] Example 1

[0037] An enzymatic banana pseudo stem fiber bamboo pulp paper with high mechanical properties, the preparation method comprising the following steps:

[0038] (1) Harvesting banana pseudo stem, the harvesting surface forms an angle of 30° with the ground, and the harvested banana pseudo stem is cleaned by using a high-pressure water gun within 24 h.

[0039] (2) The cleaned banana pseudo stem is cut into uniform segments with a length of 3-5 cm, and is dried in a drying oven at 80°C until the water content is about 10% for standby.

[0040] (3) The dried banana pseudo stem is added into a beaker, and is immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After being taken out and drained, a compound biological enzyme solution (the enzyme activity ratio of endocellulase, xylanase and lytic polysaccharide monooxygenase is 2:3:1, and the total enzyme activity is 25 U / g based on the absolute dry banana pseudo stem) is supplemented; the bath ratio of the system is adjusted to 1:20, and enzymolysis is carried out under dynamic conditions: first, reaction is carried out at pH 5.5 and 55°C for 90 min, then the pH is adjusted to 4.5 and the temperature is adjusted to 50°C for continuous reaction for 90 min; wherein the amount of rhamnolipid is 0.1wt% of the mass of the compound biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then the banana pseudo stem is washed to neutral.

[0041] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking container, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the pulp is cooked at 160°C for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0042] (5) The banana pseudo stem pulp is bleached by using an H2O2 system: the pulp concentration is 10wt% based on the mass of the absolute dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, and the reaction is carried out in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0043] (6) The bleached banana pseudo stem fiber and commercially available bamboo pulp (the pulp concentration is 10wt%) are treated by using a PFI beater to obtain bleached banana pseudo stem fiber with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fiber with different beating degrees and the bamboo pulp are mixed at a weight ratio of 1:2, 0.1wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000r to obtain mixed pulp. A paper with a basis weight of 40g / m 2 is prepared by using a Keeser automatic paper machine, the paper drying temperature is 90°C, and the time is 10 min.

[0044] Comparative Example 1-1

[0045] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method comprising the following steps:

[0046] (1) Harvesting banana pseudo stem, the harvesting surface forms an angle of 0° with the ground, and the harvested banana pseudo stem is cleaned using a high-pressure water gun within 24 h.

[0047] (2) The cleaned banana pseudo stem is cut into uniform segments with a length of 3-5 cm, and is dried in a drying oven at 80°C until the water content is about 10% for standby.

[0048] (3) The dried banana pseudo stem is added into a beaker, and is immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After being taken out and drained, a compound biological enzyme solution (the enzyme activity ratio of endocellulase, xylanase and lytic polysaccharide monooxygenase is 2:3:1, and the total enzyme activity is 25 U / g based on the absolute dry banana pseudo stem) is supplemented. The bath ratio is adjusted to 1:20, and enzymolysis is carried out under dynamic conditions: first, reaction is carried out at pH 5.5 and 55°C for 90 min, and then the pH is adjusted to 4.5 and the temperature is adjusted to 50°C for continuous reaction for 90 min. The amount of rhamnolipid is 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then the banana pseudo stem is washed to neutral.

[0049] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking container, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the banana pseudo stem is cooked at 160°C for 60 min. After the reaction is completed, the pulp is washed to neutral.

[0050] (5) The banana pseudo stem pulp is bleached by using an H2O2 system: the pulp concentration is 10 wt% based on the mass of the absolute dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, and the reaction is carried out in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0051] (6) The bleached banana pseudo stem fiber and commercially available bamboo pulp (the pulp concentration is 10 wt%) are treated by using a PFI beater to obtain bleached banana pseudo stem fiber with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fiber with different beating degrees and the bamboo pulp are mixed at a weight ratio of 1:2, 0.1 wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A paper with a basis weight of 40 g / m 2 is prepared by using a Keeser automatic paper machine, the paper drying temperature is 90°C, and the time is 10 min.

[0052] Comparative Example 1-2

[0053] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method comprising the following steps:

[0054] (1) Harvesting banana pseudo stem, the harvesting surface forms an angle of 30° with the ground, and the harvested banana pseudo stem is washed using a high-pressure water gun after 72 h.

[0055] (2) The washed banana pseudo stem is cut into uniform segments with a length of 3-5 cm, and is dried in a drying oven at 80°C until the water content is about 10% for standby.

[0056] (3) The dried banana pseudo stem is added into a beaker, and is immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After being taken out and drained, a compound biological enzyme solution (the enzyme activity ratio of endocellulase:xylanase:lytic polysaccharide monooxygenase is 2:3:1, and the total enzyme activity addition amount is 25 U / g based on the absolute dry banana pseudo stem) is supplemented; the bath ratio of the system is adjusted to 1:20, and enzymolysis is carried out under dynamic conditions: first, reaction at pH 5.5 and 55°C for 90 min, and then, the pH is adjusted to 4.5, and the temperature is adjusted to 50°C for continuous reaction for 90 min; wherein the amount of rhamnolipid is 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then, the banana pseudo stem is washed to neutral.

[0057] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking container, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the banana pseudo stem is cooked at 160°C for 60 min. After the reaction is completed, the pulp is washed to neutral.

[0058] (5) The banana pseudo stem pulp is bleached using an H2O2 system: the pulp concentration is 10 wt% based on the mass of the absolute dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, and the reaction is carried out in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0059] (6) The bleached banana pseudo stem fiber and commercially available bamboo pulp (the pulp concentration is 10 wt%) are treated by beating using a PFI beater, and bleached banana pseudo stem fiber with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR are obtained. The bleached banana pseudo stem fiber with different beating degrees and the bamboo pulp are mixed at a weight ratio of 1:2, 0.1 wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A Keesing automatic paper machine is used to prepare a paper with a basis weight of 40 g / m 2Paper is dried at 90℃ for 10 minutes.

[0060] Example 2

[0061] A high mechanical performance enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method comprising the following steps:

[0062] (1) Harvest banana pseudo stem, the harvesting surface forms an angle of 45° with the ground, and the harvested banana pseudo stem is cleaned using a high-pressure water gun within 24 hours.

[0063] (2) The cleaned banana pseudo stem is cut into uniform segments with a length of 3-5 cm, and is dried in a drying box at 80℃ until the water content is about 10% for standby.

[0064] (3) The dried banana pseudo stem is added into a beaker, and is immersed in 45℃ warm water containing rhamnolipid at a bath ratio of 1:10 for 20 minutes. After being taken out and drained, a compound biological enzyme solution (the enzyme activity ratio of endocellulase:xylanase:lytic polysaccharide monooxygenase is 2:3:1, and the total enzyme activity is 25 U / g based on the absolute dry banana pseudo stem) is added; the bath ratio is adjusted to 1:20, and enzymolysis is carried out under dynamic conditions: first, reaction is carried out at pH 5.5 and 55℃ for 90 minutes, and then, the pH is adjusted to 4.5 and the temperature is adjusted to 50℃ for continuous reaction for 90 minutes; wherein the amount of rhamnolipid is 0.1wt% of the mass of the compound biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95℃ for 20 minutes to inactivate the enzyme, and then, the banana pseudo stem is washed to neutral.

[0065] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking container, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the banana pseudo stem is cooked at 160℃ for 60 minutes. After the reaction is completed, the pulp is washed to neutral.

[0066] (5) The banana pseudo stem pulp is bleached by using an H2O2 system: the pulp concentration is 10wt% based on the mass of the absolute dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, and the reaction is carried out in a 80℃ water bath for 100 minutes. After the bleaching is completed, the pulp is washed to neutral.

[0067] (6) The bleached banana pseudo stem fiber and commercially available bamboo pulp (the pulp concentration is 10wt%) are treated by using a PFI grinder to obtain bleached banana pseudo stem fiber with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fiber with different beating degrees and the bamboo pulp are mixed at a weight ratio of 1:2, 0.1wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000r to obtain mixed pulp. The Keesing automatic paper machine is used to prepare a paper with a basis weight of 40g / m2.2 Paper of Example 1, paper drying temperature is 90℃, time is 10min.

[0068] Comparative Example 2-1

[0069] A kind of enzymatic banana pseudo stem fiber bamboo pulp paper, its preparation method includes the following steps:

[0070] (1) harvesting banana pseudo stem, the angle formed by harvesting surface and ground is 45°, and the banana pseudo stem is cleaned by high-pressure water gun within 24h after harvesting.

[0071] (2) the cleaned banana pseudo stem is cut into uniform section with length of 3-5cm, and is placed in 80℃ drying oven to dry until the moisture content is about 10% for standby.

[0072] (3) the dried banana pseudo stem is added into beaker, and is immersed in 45℃ warm water containing rhamnolipid according to bath ratio 1:20 for 20min. After being taken out and drained, compound biological enzyme liquid (endo-cellulase: xylanase: lytic polysaccharide monooxygenase enzyme activity ratio is 2:3:1, total enzyme activity addition amount is 25U / g, based on the absolute dry banana pseudo stem) is supplemented; the bath ratio of the system is adjusted to 1:20, and enzymolysis is carried out under dynamic conditions: first, reaction at pH 5.5 and temperature 55℃ for 90min, then adjust pH to 4.5 and continue to react at temperature 50℃ for 90min; wherein the amount of rhamnolipid is 0.1wt% of the mass of the compound biological enzyme liquid. After the end of enzymolysis, the temperature is quickly raised to above 95℃ for 20min to inactivate the enzyme, and then washed to neutral.

[0073] (4) the enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160℃ for 60min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0074] (5) the banana pseudo stem pulp is bleached by H2O2 system: the pulp concentration is 10wt% based on the mass of the absolute dry pulp, the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, and the reaction is carried out in 80℃ water bath for 100min. After the bleaching is completed, the pulp is washed to neutral.

[0075] (6) The bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration of 10 wt%) were treated by PFI beater to obtain the bleached banana pseudo stem fibers with beating degree of 40°SR and the bamboo pulp with beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees were mixed with the bamboo pulp at a weight ratio of 1:2, 0.1 wt% polyethylene oxide was added as a dispersing agent, and the mixed pulp was defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A paper with a basis weight of 40 g / m2was prepared by using a Keeser automatic paper machine, the drying temperature of the paper was 90 °C, and the drying time was 10 min. 2

[0076] Comparative Example 2-2

[0077] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method thereof comprises the following steps:

[0078] (1) The banana pseudo stem was harvested at an angle of 45° with the ground, and the harvested banana pseudo stem was washed by a high-pressure water gun within 24 h.

[0079] (2) The washed banana pseudo stem was cut into uniform segments with a length of 3-5 cm, and was dried in a drying box at 80 °C until the water content was about 10% to obtain a dried banana pseudo stem.

[0080] (3) The dried banana pseudo stem was added into a beaker, and was immersed in 80 °C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After being taken out and drained, a compound biological enzyme solution (the activity ratio of endocellulase, xylanase and lytic polysaccharide monooxygenase was 2:3:1, and the total enzyme activity was 25 U / g based on the absolute dry banana pseudo stem) was added; the bath ratio of the system was adjusted to 1:20, and the enzymolysis was carried out under dynamic conditions: first, the reaction was carried out at pH 5.5 and 55 °C for 90 min, then the pH was adjusted to 4.5 and the reaction was continued at 50 °C for 90 min; the amount of rhamnolipid was 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymolysis was completed, the temperature was quickly raised to above 95 °C for 20 min to inactivate the enzyme, and then the enzyme was washed to neutral.

[0081] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) was placed in a cooking container, the bath ratio was set to 1:20, the amount of NaOH was 20% (based on the mass of the absolute dry raw material), and the cooking was carried out at 160 °C for 60 min. After the reaction was completed, the pulp was washed to neutral.

[0082] (5) The H2O2 system was used to bleach the banana pseudo stem pulp: the pulp concentration was 10 wt% based on the mass of the absolute dry pulp, the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 were 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, the reaction was carried out in a 80 °C water bath for 100 min, and the pulp was washed to neutral after the bleaching was completed. ​

[0083] (6) Bleached banana pseudostem fiber and commercially available bamboo pulp (10 wt%) were beating using a PFI refiner to obtain bleached banana pseudostem fiber with a freeness of 40°SR and bamboo pulp with a freeness of 35°SR. The bleached banana pseudostem fiber with different freeness was mixed with bamboo pulp at a weight ratio of 1:2, and 0.1 wt% polyethylene oxide was added as a dispersant. The mixture was then decomposed in a fiber decomposer for 8000 r to obtain a mixed pulp. A Kaiser process automatic paper machine was used to prepare a paper with a basis weight of 40 g / m³. 2 The paper was dried at 90℃ for 10 minutes.

[0084] Comparative Examples 2-3

[0085] An enzymatically catalyzed banana pseudostem fiber bamboo pulp paper is prepared by the following steps:

[0086] (1) Harvest the banana pseudostem. The angle between the harvesting surface and the ground should be 45°. After harvesting, clean the banana pseudostem with a high-pressure water gun within 24 hours.

[0087] (2) Cut the cleaned banana pseudostem into uniform segments of 3-5cm in length, place them in an 80℃ drying oven and dry them until the moisture content is about 10% before use.

[0088] (3) Add the dried banana pseudostems to a beaker and immerse them in warm water containing rhamnolipin at 45°C for 5 minutes at a bath ratio of 1:10. After draining, add a compound biological enzyme solution (the ratio of endoplasminase: xylanase: cleaving polysaccharide monooxygenase is 2:3:1, and the total enzyme activity is 25 U / g, based on the oven-dried banana pseudostems); adjust the bath ratio of the system to 1:20, and carry out enzymatic hydrolysis under dynamic conditions: first react at pH 5.5 and temperature 55°C for 90 minutes, then adjust the pH to 4.5 and continue the reaction at temperature 50°C for 90 minutes; the amount of rhamnolipin used is 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymatic hydrolysis is completed, quickly raise the temperature to above 95°C and maintain it for 20 minutes to inactivate the enzyme, and then wash until neutral.

[0089] (4) Place the enzyme-treated and washed banana pseudostem raw material (oven dry) in a cooking container, set the bath ratio to 1:20, and the amount of NaOH to 20% (based on the mass of the oven dry raw material), cook at 160℃ for 60 min, cool after the reaction is completed, and wash the slurry until neutral.

[0090] (5) Bleaching banana pseudostem pulp using H2O2 system: Based on the dry pulp mass, the pulp concentration is 10wt%, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2%, respectively. The reaction is carried out in a water bath at 80℃ for 100min. After bleaching, the pulp is washed until neutral.

[0091] (6) Bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp consistency of 10 wt%) were beaten using a PFI beater to obtain bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees were mixed with the bamboo pulp at a weight ratio of 1:2, 0.1 wt% polyethylene oxide was added as a dispersant, and the mixed pulp was defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A paper with a basis weight of 40 g / m 2 was prepared by using a Keeser automatic paper machine, the paper drying temperature was 90°C, and the drying time was 10 min.

[0092] Example 3

[0093] A high-mechanical-property enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method comprising the following steps:

[0094] (1) Harvest the banana pseudo stem, the harvesting surface forms an angle of 45° with the ground, and the harvested banana pseudo stem is washed using a high-pressure water gun within 24 h.

[0095] (2) The washed banana pseudo stem is cut into uniform segments with a length of 3-5 cm, and is dried in a drying oven at 80°C until the water content is about 10% and then is reserved.

[0096] (3) The dried banana pseudo stem is added to a beaker, and is immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After being taken out and drained, a compound biological enzyme solution (the activity ratio of endocellulase, xylanase, and lytic polysaccharide monooxygenase is 2:3:1, and the total enzyme activity is added in an amount of 35 U / g based on the absolute dry banana pseudo stem) is supplemented. The bath ratio of the system is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first, the reaction is carried out at pH 5.5 and a temperature of 55°C for 90 min, and then the pH is adjusted to 4.5 and the temperature is adjusted to 50°C for continuous reaction for 90 min. The amount of rhamnolipid is 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymolysis is completed, the temperature is rapidly increased to above 95°C for 20 min to inactivate the enzyme, and then the washing is carried out to neutral.

[0097] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking container, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), the cooking is carried out at 160°C for 60 min, and after the reaction is completed, the pulp is washed to neutral.

[0098] (5) Bleaching the banana pseudo stem pulp using H2O2 system: the pulp concentration was 10 wt%, the dosages of H2O2, EDTA, MgSO4, NaOH, Na2SiO3 were 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, based on the mass of the absolute dry pulp, and the pulp was reacted in a water bath at 80°C for 100 min. After bleaching, the pulp was washed to neutral.

[0099] (6) The bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration was 10 wt%) were beaten using a PFI beater to obtain bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees were mixed with the bamboo pulp at a weight ratio of 1:2, 0.1 wt% polyethylene oxide was added as a dispersing agent, and the mixed pulp was defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A paper with a basis weight of 40 g / m2was prepared by using a Keeser automatic paper machine, the drying temperature of the paper was 90°C, and the drying time was 10 min. 2

[0100] Comparative Example 3-1

[0101] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method thereof comprises the following steps:

[0102] (1) Harvesting banana pseudo stems, the harvesting surface forms an angle of 45° with the ground, and the harvested banana pseudo stems are washed using a high-pressure water gun within 24 h.

[0103] (2) The washed banana pseudo stems are cut into uniform segments with a length of 3-5 cm, and are dried in a drying oven at 80°C until the water content is about 10% and then are reserved.

[0104] (3) The dried banana pseudo stems are added into a beaker, and are immersed in warm water containing rhamnolipid at 45°C for 20 min at a bath ratio of 1:10. After being taken out and drained, a compound biological enzyme solution (the activity ratio of endocellulase, xylanase and lytic polysaccharide monooxygenase is 2:3:1, and the total enzyme activity is 35 U / g, based on the absolute dry banana pseudo stem) is added; the bath ratio of the system is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first, the pH is adjusted to 4.0 and the temperature is adjusted to 55°C, and the reaction is carried out for 90 min, then the pH is adjusted to 4.5 and the temperature is adjusted to 50°C, and the reaction is continued for 90 min; wherein the dosage of rhamnolipid is 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymolysis is completed, the temperature is rapidly increased to above 95°C for 20 min to inactivate the enzyme, and then the pulp is washed to neutral.

[0105] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the dosage of NaOH is 20% (based on the mass of the absolute dry raw material), and the pulp is cooked at 160°C for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral. ​

[0106] (5) Bleaching of banana pseudo stem pulp using H2O2 system: pulp concentration was 10wt%, the dosages of H2O2, EDTA, MgSO4, NaOH, Na2SiO3 were 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, based on the mass of the absolute dry pulp, and the reaction was carried out in a water bath at 80°C for 100 min. After bleaching, the pulp was washed to neutral.

[0107] (6) Bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration was 10wt%) were beaten using a PFI beater to obtain bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees were mixed with the bamboo pulp at a weight ratio of 1:2, 0.1wt% polyethylene oxide was added as a dispersing agent, and the mixed pulp was defibrated in a fiber defibrator for 8000r to obtain a mixed pulp. A paper with a basis weight of 40g / m2 was prepared using a Keeser automatic paper machine, the drying temperature of the paper was 90°C, and the drying time was 10 min. 2

[0108] Comparative Example 3-2

[0109] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method thereof comprises the following steps:

[0110] (1) Harvesting banana pseudo stems, the harvesting surface forms an angle of 45° with the ground, and the harvested banana pseudo stems are washed using a high-pressure water gun within 24h.

[0111] (2) The washed banana pseudo stems are cut into uniform segments with a length of 3-5cm, and are dried in a drying oven at 80°C until the water content is about 10% and then are reserved.

[0112] (3) The dried banana pseudo stems are added into a beaker, and are immersed in warm water containing rhamnolipid at 45°C for 20min at a bath ratio of 1:10. After being taken out and drained, a compound enzyme solution (the activity ratio of endocellulase, xylanase and lytic polysaccharide monooxygenase is 2:3:1, and the total enzyme activity is 35U / g, based on the absolute dry banana pseudo stem) is added; the bath ratio of the system is adjusted to 1:20, and enzyme hydrolysis is carried out under dynamic conditions: first, the reaction is carried out at pH 5.5 and 80°C for 90min, then the pH is adjusted to 4.5 and the reaction is continued at 50°C for 90min; wherein the dosage of rhamnolipid is 0.1wt% of the mass of the compound enzyme solution. After the enzyme hydrolysis is completed, the temperature is rapidly increased to above 95°C for 20min to inactivate the enzyme, and then the pulp is washed to neutral.

[0113] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the dosage of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160°C for 60min. After the reaction is completed, the pulp is cooled and washed to neutral.​

[0114] (5) Bleaching of banana pseudo stem pulp using H2O2 system: pulp concentration was 10wt%, the dosages of H2O2, EDTA, MgSO4, NaOH, Na2SiO3 were 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, based on the mass of the absolute dry pulp, and the reaction was carried out in a water bath at 80℃ for 100min. After bleaching, the pulp was washed to neutral.

[0115] (6) PFI beater was used to beat the bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration was 10wt%) to obtain bleached banana pseudo stem fibers with beating degree of 40°SR and bamboo pulp with beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees were mixed with the bamboo pulp at a weight ratio of 1:2, 0.1wt% polyethylene oxide was added as a dispersing agent, and the mixed pulp was defibrated in a fiber defibrator for 8000r to obtain a mixed pulp. A paper with a basis weight of 40g / m 2 was prepared by using a Keeser automatic paper machine. The paper drying temperature was 90℃, and the time was 10min.

[0116] Comparative Example 3-3

[0117] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method thereof comprises the following steps:

[0118] (1) Harvesting banana pseudo stem, the harvesting surface forms an angle of 45° with the ground, and the harvested banana pseudo stem is washed using a high-pressure water gun within 24h.

[0119] (2) The washed banana pseudo stem is cut into uniform segments with a length of 3-5cm, and is dried in a drying oven at 80℃ until the water content is about 10% and then is reserved.

[0120] (3) The dried banana pseudo stem is added into a beaker, and is immersed in warm water containing rhamnolipid at 45℃ for 20min at a bath ratio of 1:10. After being taken out and drained, a compound biological enzyme solution (the activity ratio of endocellulase, xylanase and lytic polysaccharide monooxygenase is 2:3:1, and the total enzyme activity is added in an amount of 35U / g based on the absolute dry banana pseudo stem) is supplemented; the bath ratio of the system is adjusted to 1:20, and enzyme hydrolysis is carried out under dynamic conditions: first, the pH is adjusted to 5.5 and the temperature is adjusted to 55℃ for 30min, then the pH is adjusted to 4.5 and the temperature is adjusted to 50℃ for 90min; wherein the dosage of rhamnolipid is 0.1wt% of the mass of the compound biological enzyme solution. After enzyme hydrolysis, the temperature is rapidly increased to above 95℃ for 20min to inactivate the enzyme, and then the pulp is washed to neutral.

[0121] (4) The enzyme-treated and washed banana pseudostem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160°C for 60 min. After the reaction is completed, the slurry is cooled and washed to neutral.

[0122] (5) The banana pseudostem slurry is bleached by using the H2O2 system: the slurry concentration is 10 wt% based on the mass of the absolute dry slurry, and the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively. The reaction is carried out in a water bath at 80°C for 100 min. After the bleaching is completed, the slurry is washed to neutral.

[0123] (6) The bleached banana pseudostem fibers and commercially available bamboo pulp (the slurry concentration is 10 wt%) are beaten by using a PFI beater to obtain bleached banana pseudostem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudostem fibers with different beating degrees are mixed with the bamboo pulp at a weight ratio of 1:2, 0.1 wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000 r to obtain a mixed slurry. A Keeser automatic papermaking machine is used to prepare paper with a basis weight of 40 g / m 2 at a drying temperature of 90°C for 10 min.

[0124] Comparative Examples 3-4

[0125] An enzymatic banana pseudostem fiber bamboo pulp paper is prepared by the following method:

[0126] (1) The banana pseudostem is harvested, and the harvesting surface forms an angle of 45° with the ground. The harvested banana pseudostem is cleaned by using a high-pressure water gun within 24 h.

[0127] (2) The cleaned banana pseudostem is cut into uniform segments with a length of 3-5 cm, dried in a drying oven at 80°C until the water content is about 10%, and then reserved.

[0128] (3) The dried banana pseudostem is added to a beaker, immersed in warm water containing rhamnolipid at 45°C for 20 min at a bath ratio of 1:10. After being taken out and drained, a compound biological enzyme solution (the ratio of endocellulase, xylanase, and lytic polysaccharide monooxygenase enzyme activities is 2:3:1, and the total enzyme activity is added in an amount of 35 U / g based on the absolute dry banana pseudostem) is supplemented. The bath ratio of the system is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first, the reaction is carried out at pH 5.5 and 55°C for 90 min, and then the pH is adjusted to 3.0 and the temperature is adjusted to 50°C for continuous reaction for 90 min. The amount of rhamnolipid is 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then the slurry is washed to neutral.

[0129] (4) Place the enzyme-treated and washed banana pseudostem raw material (oven dry) in a cooking container, set the bath ratio to 1:20, and the amount of NaOH to 20% (based on the mass of the oven dry raw material), cook at 160℃ for 60 min, cool after the reaction is completed, and wash the slurry until neutral.

[0130] (5) Bleaching banana pseudostem pulp using H2O2 system: Based on the dry pulp mass, the pulp concentration is 10wt%, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2%, respectively. The reaction is carried out in a water bath at 80℃ for 100min. After bleaching, the pulp is washed until neutral.

[0131] (6) Bleached banana pseudostem fiber and commercially available bamboo pulp (10 wt%) were beating using a PFI refiner to obtain bleached banana pseudostem fiber with a freeness of 40°SR and bamboo pulp with a freeness of 35°SR. The bleached banana pseudostem fiber with different freeness was mixed with bamboo pulp at a weight ratio of 1:2, and 0.1 wt% polyethylene oxide was added as a dispersant. The mixture was then decomposed in a fiber decomposer for 8000 r to obtain a mixed pulp. A Kaiser process automatic paper machine was used to prepare a paper with a basis weight of 40 g / m³. 2 The paper was dried at 90℃ for 10 minutes.

[0132] Comparative Examples 3-5

[0133] An enzymatically catalyzed banana pseudostem fiber bamboo pulp paper is prepared by the following steps:

[0134] (1) Harvest the banana pseudostem. The angle between the harvesting surface and the ground should be 45°. After harvesting, clean the banana pseudostem with a high-pressure water gun within 24 hours.

[0135] (2) Cut the cleaned banana pseudostem into uniform segments of 3-5cm in length, place them in an 80℃ drying oven and dry them until the moisture content is about 10% before use.

[0136] (3) Add the dried banana pseudostems to a beaker and immerse them in warm water containing rhamnolipin at 45°C for 20 minutes at a bath ratio of 1:10. After draining, add a compound biological enzyme solution (the ratio of endoglucanase: xylanase: cleaving polysaccharide monooxygenase is 2:3:1, and the total enzyme activity is 35 U / g, based on the oven-dried banana pseudostems); adjust the bath ratio of the system to 1:20, and carry out enzymatic hydrolysis under dynamic conditions: first react at pH 5.5 and temperature 55°C for 90 minutes, then adjust the pH to 4.5 and continue the reaction at temperature 80°C for 90 minutes; the amount of rhamnolipin used is 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymatic hydrolysis is completed, quickly raise the temperature to above 95°C and maintain it for 20 minutes to inactivate the enzyme, and then wash until neutral.

[0137] (4) The enzyme treated and washed banana pseudo stem raw material (absolute dry) was placed in a cooking vessel, bath ratio was set to 1:20, NaOH dosage was 20% (based on the mass of the absolute dry raw material), and the cooking was carried out at 160°C for 60 min. After the reaction was completed, the slurry was cooled and washed to neutral.

[0138] (5) The bleaching of the banana pseudo stem slurry was carried out using H2O2 system: the slurry concentration was 10 wt% based on the mass of the absolute dry slurry, and the dosages of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 were 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively. The reaction was carried out in a water bath at 80°C for 100 min. After the bleaching was completed, the slurry was washed to neutral.

[0139] (6) The bleached banana pseudo stem fibers and commercially available bamboo pulp (slurry concentration was 10 wt%) were beaten using a PFI beater to obtain bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees were mixed with the bamboo pulp at a weight ratio of 1:2, 0.1 wt% polyethylene oxide was added as a dispersant, and the mixture was defibrated in a fiber defibrator for 8000 r to obtain a mixed slurry. A Keeser automatic paper machine was used to prepare paper with a basis weight of 40 g / m 2 at a drying temperature of 90°C for 10 min.

[0140] Comparative Examples 3-6

[0141] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method thereof comprising the following steps:

[0142] (1) The banana pseudo stem was harvested, and the harvesting surface was at an angle of 45° with the ground. The harvested banana pseudo stem was cleaned using a high-pressure water gun within 24 h.

[0143] (2) The cleaned banana pseudo stem was cut into uniform segments with a length of 3-5 cm, and was dried in a drying oven at 80°C until the water content was about 10% for later use.

[0144] (3) The dried banana pseudo stem is added into a beaker and immersed in 45℃ warm water containing rhamnolipid for 20 min at a bath ratio of 1:10. After being taken out and drained, the complex biological enzyme solution (endo-cellulase: xylanase: lytic polysaccharide monooxygenase enzyme activity ratio is 2:3:1, and the total enzyme activity is added in an amount of 35 U / g based on the dry banana pseudo stem) is supplemented. The bath ratio of the system is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first, the reaction is carried out at pH 5.5 and 55℃ for 90 min, and then the pH is adjusted to 4.5 and the temperature is adjusted to 50℃ for continuous reaction for 30 min. The amount of rhamnolipid is 0.1wt% of the mass of the complex biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95℃ for 20 min to inactivate the enzyme, and then the pulp is washed to neutral.

[0145] (4) The enzyme-treated and washed banana pseudo stem raw material (dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the dry raw material), and the cooking is carried out at 160℃ for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0146] (5) The banana pseudo stem pulp is bleached by using H2O2 system: the pulp concentration is 10wt% based on the mass of the dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, and the reaction is carried out in a 80℃ water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0147] (6) The bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration is 10wt%) are beaten by using a PFI beater to obtain bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees are mixed with the bamboo pulp at a weight ratio of 1:2, 0.1wt% polyethylene oxide is added as a dispersant, and the mixed pulp is defibrated in a fiber defibrator for 8000r to obtain a mixed pulp. A Keeser automatic paper machine is used to prepare paper with a basis weight of 40g / m 2 The paper is dried at a temperature of 90℃ for 10 min.

[0148] Comparative Examples 3-7

[0149] An enzymatic banana pseudo stem fiber bamboo pulp paper, and a preparation method thereof, the preparation method comprising the following steps:

[0150] (1) The banana pseudo stem is harvested, and the harvesting surface is at an angle of 45° with the ground. The harvested banana pseudo stem is cleaned by using a high-pressure water gun within 24h.

[0151] (2) The cleaned banana pseudo stem is cut into uniform segments with a length of 3-5cm, and is dried in a 80℃ drying oven until the water content is about 10% for standby.

[0152] (3) The dried banana pseudo stem is added into a beaker and immersed in 45℃ warm water containing rhamnolipid for 20 min at a bath ratio of 1:10. After being taken out and drained, the composite enzyme solution (endo-cellulase: xylanase enzyme activity ratio of 2:3, total enzyme activity addition amount of 35 U / g, based on the absolute dry banana pseudo stem) is supplemented. The bath ratio of the system is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first, reaction at pH 5.5 and 55℃ for 90 min, and then, the pH is adjusted to 4.5 and the temperature is adjusted to 50℃ for continuous reaction for 90 min; wherein the amount of rhamnolipid is 0.1wt% of the mass of the composite enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95℃ for 20 min to inactivate the enzyme, and then the pulp is washed to neutral.

[0153] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160℃ for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0154] (5) The banana pseudo stem pulp is bleached by using the H2O2 system: the pulp concentration is 10wt% based on the mass of the absolute dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively, and the reaction is carried out in a 80℃ water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0155] (6) The bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration of 10wt%) are beaten by using a PFI beater to obtain bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees and the bamboo pulp are mixed in a weight ratio of 1:2, 0.1wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000r to obtain a mixed pulp. A Keeser automatic paper machine is used to prepare paper with a basis weight of 40g / m 2

[0156] Comparative Examples 3-8

[0157] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method thereof comprises the following steps:

[0158] (1) The banana pseudo stem is harvested, and the harvesting surface is at an angle of 45° with the ground. The harvested banana pseudo stem is cleaned by using a high-pressure water gun within 24h.

[0159] (2) The cleaned banana pseudo stem is cut into uniform segments with a length of 3-5cm, and is dried in a 80℃ drying oven until the water content is about 10% for standby. ​

[0160] (3) The dried banana pseudo stem is added to a beaker and immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After being taken out and drained, a complex biological enzyme solution (endo-cellulase: lytic polysaccharide monooxygenase enzyme activity ratio of 2:1, total enzyme activity addition amount of 35 U / g, based on the absolute dry banana pseudo stem) is added. The bath ratio of the system is adjusted to 1:20, and enzymolysis is carried out under dynamic conditions: first at pH 5.5 and 55°C for 90 min, and then at pH 4.5 and 50°C for 90 min. The amount of rhamnolipid is 0.1 wt% of the mass of the complex biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then the product is washed to neutral.

[0161] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160°C for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0162] (5) The banana pseudo stem pulp is bleached using an H2O2 system: the pulp concentration is 10 wt%, and the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively, based on the mass of the absolute dry pulp. The reaction is carried out in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0163] (6) The bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration of 10 wt%) are beaten using a PFI beater to obtain bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees are mixed with the bamboo pulp at a weight ratio of 1:2, 0.1 wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A Kelsey automatic paper machine is used to prepare paper with a basis weight of 40 g / m 2

[0164] Comparative Examples 3-9

[0165] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method thereof comprising the following steps:

[0166] (1) The banana pseudo stem is harvested, and the harvesting surface forms an angle of 45° with the ground. The harvested banana pseudo stem is cleaned using a high-pressure water gun within 24 h.

[0167] (2) The cleaned banana pseudo stem is cut into uniform segments with a length of 3-5 cm, and is dried in a 80°C drying oven until the water content is about 10% for later use. ​

[0168] (3) The dried banana pseudo stem is added into a beaker and immersed in 45℃ warm water containing rhamnolipid for 20 min at a bath ratio of 1:10. After being taken out and drained, the composite enzyme solution (xylanase: lytic polysaccharide monooxygenase enzyme activity ratio of 3:1, total enzyme activity addition amount is 35 U / g, based on the absolute dry banana pseudo stem) is supplemented. The bath ratio of the system is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first at pH 5.5 and 55℃ for 90 min, and then at pH 4.5 and 50℃ for 90 min. The amount of rhamnolipid is 0.1wt% of the mass of the composite enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95℃ for 20 min to inactivate the enzyme, and then the washing is carried out to neutral.

[0169] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking container, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160℃ for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0170] (5) The H2O2 system is used to bleach the banana pseudo stem pulp: the pulp concentration is 10wt% based on the mass of the absolute dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2% respectively. The reaction is carried out in a 80℃ water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0171] (6) The PFI grinder is used to pulp the bleached banana pseudo stem fibers and the commercially available bamboo pulp (pulp concentration is 10wt%). The bleached banana pseudo stem fibers with a beating degree of 40°SR and the bamboo pulp with a beating degree of 35°SR are obtained. The bleached banana pseudo stem fibers with different beating degrees and the bamboo pulp are mixed in a weight ratio of 1:2, 0.1wt% polyethylene oxide is added as a dispersing agent, and the mixed pulp is defibrated in a fiber defibrator for 8000r to obtain a mixed pulp. A Keeser automatic paper machine is used to prepare paper with a basis weight of 40g / m 2 The paper drying temperature is 90℃, and the time is 10 min.

[0172] Example 4

[0173] A high-mechanical-property enzymatic banana pseudo stem fiber bamboo pulp paper is prepared by the following steps:

[0174] (1) The banana pseudo stem is harvested, and the harvesting surface forms an angle of 45° with the ground. The harvested banana pseudo stem is washed using a high-pressure water gun within 24h.

[0175] (2) The washed banana pseudo stem is cut into uniform segments with a length of 3-5cm, and is dried in a 80℃ drying box until the water content is about 10% for standby.

[0176] (3) The dried banana pseudo stem is added to a beaker and immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After draining, the composite enzyme solution (endo-cellulase: xylanase: lytic polysaccharide monooxygenase enzyme activity ratio of 2:4:1, total enzyme activity added amount is 35 U / g, based on the absolute dry banana pseudo stem) is supplemented; the bath ratio of the system is adjusted to 1:20, and enzymolysis is carried out under dynamic conditions: first at pH 5.5, 55°C for 90 min, then the pH is adjusted to 4.5, and the temperature is adjusted to 50°C for 90 min; the amount of rhamnolipid is 0.1wt% of the mass of the composite enzyme solution. After the end of the enzymolysis, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then the pulp is washed to neutral.

[0177] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the pulp is cooked at 160°C for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0178] (5) The banana pseudo stem pulp is bleached using an H2O2 system: the pulp concentration is 10wt% based on the mass of the absolute dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively. The reaction is carried out in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0179] (6) The bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration of 10wt%) are beaten using a PFI beater to obtain bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees are mixed with the bamboo pulp at a weight ratio of 1:2, 0.1wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000r to obtain a mixed pulp. A Kelsey automatic paper machine is used to prepare paper with a basis weight of 40g / m 2

[0180] Comparative Example 4-1

[0181] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method comprising the following steps:

[0182] (1) The banana pseudo stem is harvested, and the harvesting surface forms an angle of 45° with the ground. The harvested banana pseudo stem is washed using a high-pressure water gun within 24h.

[0183] (2) The washed banana pseudo stem is cut into uniform segments with a length of 3-5cm, and is dried in a 80°C drying oven until the water content is about 10% for standby use.​

[0184] (3) The dried banana pseudo stem is added to a beaker and immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After draining, the composite enzyme solution (endo-cellulase: xylanase: lytic polysaccharide monooxygenase enzyme activity ratio of 2:4:1, total enzyme activity added amount is 35 U / g, based on the absolute dry banana pseudo stem) is supplemented. The bath ratio of the system is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first at pH 5.5 and 55°C for 90 min, and then at pH 4.5 and 50°C for 90 min. The amount of rhamnolipid is 0.1 wt% of the mass of the composite enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then the pulp is washed to neutral.

[0185] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 28% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160°C for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0186] (5) The H2O2 system is used to bleach the banana pseudo stem pulp: the pulp concentration is 10 wt%, the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively, based on the mass of the absolute dry pulp, and the reaction is carried out in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0187] (6) The PFI grinder is used to pulp the bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration is 10 wt%), and the bleached banana pseudo stem fibers and the bamboo pulp with a beating degree of 40°SR and 35°SR, respectively, are mixed at a weight ratio of 1:2, 0.1 wt% polyethylene oxide is added as a dispersant, and the mixed pulp is defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A Keeser automatic paper machine is used to prepare paper with a basis weight of 40 g / m 2

[0188] Comparative Example 4-2

[0189] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method thereof comprises the following steps:

[0190] (1) The banana pseudo stem is harvested, the harvesting surface forms an angle of 45° with the ground, and the harvested banana pseudo stem is washed using a high-pressure water gun within 24 h.

[0191] ​(2) The cleaned banana pseudo stem is cut into uniform segments of 3-5 cm in length, and dried in a drying oven at 80°C until the moisture content is about 10% for later use.

[0192] (3) The dried banana pseudo stem is added to a beaker and immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After draining, the composite biological enzyme solution (endo-cellulase: xylanase: lytic polysaccharide monooxygenase enzyme activity ratio of 2:4:1, total enzyme activity addition amount is 35 U / g, based on the absolute dry banana pseudo stem) is supplemented; the bath ratio is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first at pH 5.5, temperature 55°C for 90 min, then the pH is adjusted to 4.5, temperature 50°C for 90 min; the amount of rhamnolipid is 0.1wt% of the mass of the composite biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then washed to neutral.

[0193] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 130°C for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0194] (5) The H2O2 system is used to bleach the banana pseudo stem pulp: the pulp concentration is 10wt% based on the mass of the absolute dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively. The reaction is carried out in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0195] (6) The bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration of 10wt%) are treated by beating with a PFI beater, and bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR are obtained. The bleached banana pseudo stem fibers with different beating degrees are mixed with the bamboo pulp at a weight ratio of 1:2, 0.1wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000r to obtain a mixed pulp. A Keeser automatic paper machine is used to prepare paper with a basis weight of 40g / m 2

[0196] Comparative Example 4-3

[0197] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method thereof comprises the following steps:

[0198] (1) The banana pseudo stem is harvested, and the harvesting surface is at an angle of 45° with the ground. The harvested banana pseudo stem is cleaned with a high-pressure water gun within 24h. ​

[0199] (2) The cleaned banana pseudo stem is cut into uniform segments of 3-5 cm in length, dried in a drying oven at 80°C until the moisture content is about 10%, and then used.

[0200] (3) The dried banana pseudo stem is added to a beaker, immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After draining, the complex biological enzyme solution (endo-cellulase: xylanase: lytic polysaccharide monooxygenase enzyme activity ratio 2:4:1, total enzyme activity addition amount 35 U / g, based on the absolute dry banana pseudo stem) is supplemented. The bath ratio is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first at pH 5.5, 55°C for 90 min, then at pH 4.5, 50°C for 90 min. The amount of rhamnolipid is 0.1 wt% of the mass of the complex biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then washed to neutral.

[0201] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160°C for 90 min. After the reaction is completed, the pulp is washed to neutral.

[0202] (5) The banana pseudo stem pulp is bleached using the H2O2 system: the pulp concentration is 10 wt%, the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively, based on the mass of the absolute dry pulp, and the reaction is carried out in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0203] (6) The bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration 10 wt%) are beaten using a PFI beater to obtain bleached banana pseudo stem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudo stem fibers with different beating degrees are mixed with the bamboo pulp at a weight ratio of 1:2, 0.1 wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A Keeser automatic paper machine is used to prepare paper with a basis weight of 40 g / m 2

[0204] Example 5

[0205] A high-mechanical-property enzymatic banana pseudo stem fiber bamboo pulp paper is prepared by the following method:

[0206] (1) The banana pseudo stem is harvested at an angle of 45° with the ground, and the harvested banana pseudo stem is cleaned using a high-pressure water gun within 24 h.​

[0207] (2) The cleaned banana pseudo stem is cut into uniform segments of 3-5 cm in length, and dried in a drying oven at 80°C until the moisture content is about 10% for later use.

[0208] (3) The dried banana pseudo stem is added to a beaker and immersed in warm water containing rhamnolipid at 45°C for 20 min at a bath ratio of 1:10. After draining, the complex biological enzyme solution (endo-cellulase: xylanase: lytic polysaccharide monooxygenase enzyme activity ratio of 1:3:1, total enzyme activity addition amount is 35 U / g, based on the absolute dry banana pseudo stem) is supplemented; the bath ratio is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first at pH 5.5, temperature 55°C for 90 min, then the pH is adjusted to 4.5, the temperature is 50°C, and the reaction is continued for 90 min; the amount of rhamnolipid is 0.1wt% of the mass of the complex biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then washed to neutral.

[0209] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking vessel, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160°C for 60 min. After the reaction is completed, the pulp is washed to neutral.

[0210] (5) The H2O2 system is used to bleach the banana pseudo stem pulp: based on the mass of the absolute dry pulp, the pulp concentration is 10wt%, the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively, and the reaction is carried out in a water bath at 80°C for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0211] (6) The PFI grinder is used to pulp the bleached banana pseudo stem fibers and commercially available bamboo pulp (pulp concentration of 10wt%), and bleached banana pseudo stem fibers and bamboo pulp with a beating degree of 40°SR and 35°SR, respectively, are mixed in a weight ratio of 1:2, 0.1wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000r to obtain a mixed pulp. A Keeser automatic paper machine is used to prepare paper with a basis weight of 40g / m 2

[0212] Comparative Example 5-1

[0213] An enzymatic banana pseudo stem fiber bamboo pulp paper, the preparation method comprising the following steps:

[0214] ​(1) Harvesting banana pseudostem, the harvesting surface forms an angle of 45° with the ground, and the harvested banana pseudostem is cleaned within 24 h using a high-pressure water gun.

[0215] (2) The cleaned banana pseudostem is cut into uniform segments with a length of 3-5 cm, and is dried in a drying oven at 80°C until the water content is about 10% to obtain the dried banana pseudostem.

[0216] (3) The dried banana pseudostem is added to a beaker, and is immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After being taken out and drained, a compound biological enzyme solution (the ratio of endocellulase, xylanase and lytic polysaccharide monooxygenase is 1:3:1, and the total enzyme activity is 35 U / g, based on the absolute dry banana pseudostem) is added. The bath ratio is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first, the reaction is carried out at pH 5.5 and 55°C for 90 min, and then the pH is adjusted to 4.5 and the reaction is continued at 50°C for 90 min. The amount of rhamnolipid is 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then the product is washed to neutral.

[0217] (4) The enzyme-treated and washed banana pseudostem raw material (absolute dry) is placed in a cooking container, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160°C for 60 min. After the reaction is completed, the pulp is washed to neutral.

[0218] (5) The H2O2 system is used to bleach the banana pseudostem pulp: the pulp concentration is 15 wt% based on the mass of the absolute dry pulp, and the amounts of H2O2, EDTA, MgSO4, NaOH and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5% and 1.2%, respectively. The reaction is carried out in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0219] (6) The bleached banana pseudostem fibers and commercially available bamboo pulp (the pulp concentration is 10 wt%) are treated by beating using a PFI beater to obtain bleached banana pseudostem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR. The bleached banana pseudostem fibers with different beating degrees are mixed with the bamboo pulp at a weight ratio of 1:2, 0.1 wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A Kelsey automatic paper machine is used to prepare paper with a basis weight of 40 g / m 2

[0220] Comparative Example 5-2

[0221] An enzymatic banana pseudostem fiber bamboo pulp paper is prepared by the following steps: ​

[0222] (1) Harvesting banana pseudostem, the harvesting surface forms an angle of 45° with the ground, and the harvested banana pseudostem is cleaned within 24 h using a high-pressure water gun.

[0223] (2) The cleaned banana pseudostem is cut into uniform segments with a length of 3-5 cm, and is dried in a drying oven at 80°C until the water content is about 10% to obtain the dried banana pseudostem.

[0224] (3) The dried banana pseudostem is added to a beaker, and is immersed in 45°C warm water containing rhamnolipid at a bath ratio of 1:10 for 20 min. After being taken out and drained, a compound biological enzyme solution (the enzyme activity ratio of endocellulase, xylanase, and lytic polysaccharide monooxygenase is 1:3:1, and the total enzyme activity is 35 U / g, based on the absolute dry banana pseudostem) is added. The bath ratio is adjusted to 1:20, and enzymolysis is performed under dynamic conditions: first, reaction at pH 5.5 and 55°C for 90 min, and then, reaction at pH 4.5 and 50°C for 90 min. The amount of rhamnolipid is 0.1 wt% of the mass of the compound biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95°C for 20 min to inactivate the enzyme, and then, the product is washed to neutral.

[0225] (4) The enzyme-treated and washed banana pseudostem (absolute dry) is placed in a cooking container, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the pulp is cooked at 160°C for 60 min. After the reaction is completed, the pulp is cooled and washed to neutral.

[0226] (5) The banana pseudostem pulp is bleached using an H2O2 system: the pulp concentration is 10 wt%, and the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively, based on the mass of the absolute dry pulp. The reaction is performed in a 80°C water bath for 100 min. After the bleaching is completed, the pulp is washed to neutral.

[0227] (6) The bleached banana pseudostem fibers and commercially available bamboo pulp (pulp concentration is 10 wt%) are treated by beating using a PFI beater, and bleached banana pseudostem fibers with a beating degree of 40°SR and bamboo pulp with a beating degree of 35°SR are obtained. The bleached banana pseudostem fibers with different beating degrees and the bamboo pulp are mixed at a weight ratio of 1:2, 0.1 wt% polyethylene oxide is added as a dispersant, and the mixture is defibrated in a fiber defibrator for 8000 r to obtain a mixed pulp. A Kelsey automatic paper machine is used to prepare paper with a basis weight of 40 g / m 2

[0228] Comparative Example 5-3

[0229] An enzymatic banana pseudostem fiber bamboo pulp paper is prepared by the following steps:​

[0230] (1) Harvest the banana pseudo stem, the harvesting surface forms an angle of 45° with the ground, and the banana pseudo stem is cleaned within 24h using a high-pressure water gun.

[0231] (2) The cleaned banana pseudo stem is cut into uniform segments with a length of 3-5cm, dried in a drying oven at 80℃ until the water content is about 10%, and then used.

[0232] (3) The dried banana pseudo stem is added to a beaker, immersed in 45℃ warm water containing rhamnolipid at a bath ratio of 1:10 for 20min. After draining, the complex biological enzyme solution (endo-cellulase: xylanase: lytic polysaccharide monooxygenase enzyme activity ratio is 1:3:1, total enzyme activity addition amount is 35U / g, based on the absolute dry banana pseudo stem) is supplemented; the bath ratio of the system is adjusted to 1:20, and the enzymolysis is carried out under dynamic conditions: first at pH 5.5, temperature 55℃ for 90min, then adjust the pH to 4.5, continue to react at 50℃ for 90min; wherein the amount of rhamnolipid is 0.1wt% of the mass of the complex biological enzyme solution. After the enzymolysis is completed, the temperature is quickly raised to above 95℃ for 20min to inactivate the enzyme, and then washed to neutral.

[0233] (4) The enzyme-treated and washed banana pseudo stem raw material (absolute dry) is placed in a cooking container, the bath ratio is set to 1:20, the amount of NaOH is 20% (based on the mass of the absolute dry raw material), and the cooking is carried out at 160℃ for 60min. After the reaction is completed, the pulp is washed to neutral.

[0234] (5) The H2O2 system is used to bleach the banana pseudo stem pulp: based on the mass of the absolute dry pulp, the pulp concentration is 10wt%, the amounts of H2O2, EDTA, MgSO4, NaOH, and Na2SiO3 are 4.0%, 0.8%, 0.03%, 1.5%, and 1.2%, respectively, and the reaction is carried out in a 80℃ water bath for 150min. After the bleaching is completed, the pulp is washed to neutral.

[0235] (6) The PFI grinder is used to pulp the bleached banana pseudo stem fiber and the commercially available bamboo pulp (pulp concentration is 10wt%), and the bleached banana pseudo stem fiber and the bamboo pulp with a beating degree of 40°SR and 35°SR, respectively, are mixed in a weight ratio of 1:2, 0.1wt% polyethylene oxide is added as a dispersant, and the mixed pulp is defibrated in a fiber defibrator for 8000r to obtain a mixed pulp. The Keeser automatic paper machine is used to prepare paper with a basis weight of 40g / m 2

[0236] Verification Example 1

[0237] ​The bamboo pulp paper prepared by the blank example, the example and the comparative example was subjected to paper performance analysis, and the specific steps were as follows:

[0238] The paper was placed in a constant temperature and humidity (23℃, 50%) environment for 24 hours, and the paper was subjected to quantitative (GB / T 451.2—2023), thickness (GB / T 451.3—2002), tensile strength (GB / T 12914—2018), tear resistance (GB / T 455—2002), burst resistance (GB / T 454—2020), folding endurance (GB / T 457—2008) and other indexes according to the national relevant standards.

[0239] Table 1 Mechanical strength performance of enzymatic banana pseudostem fiber bamboo pulp paper

[0240] Group Tensile index / Nm / g -1 ]] Tear index / mN.m 2 ·g -1 ]]> Resistance index / kPa.m 2 ·g -1 ]]> Folding number / time Blank 45.21 7.66 3.42 386 Example 1 55.21 8.02 4.63 1448 Comparative Example 1-1 42.16 6.63 3.28 311 Comparative Example 1-2 40.32 6.34 3.05 326 Example 2 56.34 8.21 4.51 1503 Comparative Example 2-1 45.18 7.49 3.26 351 Comparative Example 2-2 43.96 7.61 3.08 367 Comparative Example 2-3 41.62 7.35 3.11 330 Example 3 58.67 9.07 4.82 1574 Comparative Example 3-1 42.01 6.33 3.42 325 Comparative Example 3-2 38.67 4.75 2.73 178 Comparative Example 3-3 43.91 6.83 3.34 319 Comparative Example 3-4 44.09 7.06 3.36 337 Comparative Example 3-5 43.57 6.71 3.07 308 Comparative Example 3-6 45.06 7.41 3.38 361 Comparative Example 3-7 54.06 8.36 4.57 1261 Comparative Example 3-8 51.39 8.89 4.28 1224 Comparative Example 3-9 48.76 8.82 3.62 908 Example 4 59.87 9.26 4.97 1706 Comparative Example 4-1 42.18 7.06 3.04 344 Comparative Example 4-2 40.08 6.13 2.43 346 Comparative Example 4-3 43.81 6.48 3.06 308 Example 5 61.03 9.13 5.11 1934 Comparative Example 5-1 41.84 7.28 3.13 347 Comparative Example 5-2 38.54 6.42 2.87 322 Comparative Example 5-3 36.42 6.37 2.46 306

[0241] According to the above results, the bamboo pulp paper prepared by the preparation method of the present application has excellent mechanical properties, wherein the specific processes of pre-impregnation, enzymatic reaction, alkali treatment, bleaching and the like can effectively improve the fiber properties of banana pseudostem fiber, so that the strength of the bamboo pulp paper can be enhanced to a certain extent, and the performance of the bamboo pulp paper is improved. The pre-impregnation can save water and heat energy by using a lower bath ratio, and the swelling is started at a mild temperature. The short-time treatment can preliminarily dissolve the soluble impurities, which can create a uniform and clean fiber substrate for subsequent enzymatic hydrolysis, improve the efficiency of enzyme action, and is the prelude to efficient pretreatment.

[0242] The enzymatic hydrolysis process simulates the timing of biological degradation. In the first stage, xylanase and endo-cellulase are optimally active, rapidly breaking down the hemicellulose structure. Endo-cellulase randomly cuts inside the cellulose chain, which is the key to initiating internal fibrillation of the fiber, softening the fiber and exposing a large number of hydroxyl groups to form hydrogen bonds, thereby improving paper strength. Xylanase enhances the swelling of the fiber and the subsequent action of the enzyme by degrading the hemicellulose wrapped around the fiber, thereby improving the bonding strength of the fiber; the acidic environment in the second stage is conducive to the oxidative cutting of strong connecting bonds by lytic polysaccharide monooxygenase. Lytic polysaccharide monooxygenase has a unique effect on breaking down the primary cell wall and loosening the crystalline region by oxidizing the surface of crystalline cellulose, which can soften the fiber and enhance the degree of fiber separation and swelling. The three enzymes promote each other, which can better achieve the preparation of pulp and the improvement of papermaking performance. Through dynamic optimization of the activity window of each enzyme component, the synergistic effect of the three enzymes is achieved, and a more in-depth pretreatment effect is achieved in a shorter time. Xylanase is used to remove hemicellulose, and endo-cellulase is used to assist in the amorphization of the fiber; lytic polysaccharide monooxygenase is innovatively introduced, which can specifically attack the crystalline region and lignin-carbohydrate complex with its oxidation ability, and can more effectively achieve component depolymerization, which is a key technical prerequisite for significantly reducing the amount of subsequent alkali treatment. By using more efficient enzymes and a more reasonable step-by-step process, the amount of enzymes required per unit of raw material is reduced, the treatment effect is guaranteed or even improved, the cost of biological treatment is directly reduced, and the economic feasibility of the process is improved; unsuitable enzyme treatment conditions can greatly reduce enzyme activity, reduce treatment effect, and affect fiber performance, thereby affecting paper performance.

[0243] The adjustment of the alkali treatment process parameters relies on the fact that after deep enzyme treatment, the lignin in the fiber raw material has been significantly exposed and loosened, and the dependence on strong alkali and high temperature has been greatly reduced, which is the most significant environmental and economic benefit of the present application. The chemical consumption, energy consumption, and wastewater load are significantly reduced. During the bleaching process, the pretreatment obtains purer pulp (lower hemicellulose and lignin content), which requires less bleaching agent to achieve whiteness. Therefore, the use of chemicals is further reduced, and the damage to the strength of the fiber caused by high temperature is reduced, which helps to maintain the physical properties of the final paper.

[0244] At the same time, if the cutting and cleaning conditions are not suitable, it may cause problems such as mold and rot of the sample, and other forms of changes in fiber structure and content ratio, such as an increase in fiber bundle content, fiber curling, and shortening, which can reduce the performance of the fiber and the paper. In general, the steps and parameter selection of the process of the present application are interrelated and coupled. Through the overall parameter setting, the preparation of the pulp and the improvement of the papermaking performance are achieved.

[0245] The above specific embodiments part of the present application is related to the analysis method has carried out the specific introduction. It should be noted that the above introduction is only for helping the person skilled in the art to better understand the method and the idea of the present application, and is not limited to the related content. Without departing from the principle of the present application, the person skilled in the art can also make proper adjustment or modification to the present application, and the above adjustment and modification should also belong to the protection scope of the present application.

Claims

1. A process for the preparation of high mechanical performance enzymatic banana pseudo stem fiber bagasse paper characterized by, It comprises the following steps: (1) harvesting, cleaning, cutting, drying, enzyme treatment, alkali treatment, washing, bleaching and washing to neutral of banana pseudostem to prepare banana pseudostem pulp; (2) beating the banana pseudostem pulp and bamboo pulp prepared in step (1) respectively, mixing them according to a certain proportion, adding a dispersing agent, defibrating, sheeting and drying to prepare bamboo pulp paper.

2. The production method according to claim 1, characterized by, When the banana pseudostem is harvested, the angle between the cutting surface and the ground should be between 30°-60°, and the harvested banana pseudostem must be treated within 24 hours after harvesting.

3. The preparation method according to claim 1, characterized in that, The cleaning, cutting and drying process in step (1) is as follows: the harvested banana pseudostem is cleaned with high-pressure water and cut into uniform blocks with a length of 3-5 cm, and then dried in a 75-85℃ drying oven until the moisture content is 8-12%.

4. The production method according to claim 1, characterized by, The enzyme treatment process in step (1) is as follows: a. Pre-treatment soaking: soak the dried banana pseudostem segments in 40-50℃ water containing a surfactant at a bath ratio of 1:8-12 for 10-30 min; b. Stepwise synergistic enzymolysis: after draining, supplement a complex biological enzyme solution and adjust the bath ratio to 1:15-25 for enzyme hydrolysis; c. Post-treatment: after enzyme hydrolysis, quickly raise the temperature to above 95℃ for 15-25 min to inactivate the enzyme, and then wash to neutral.

5. The production method according to claim 4, characterized by, The surfactant in step a is selected from one or more of rhamnolipids, sucrose esters and polysorbate-80.

6. The preparation method according to claim 4, characterized in that, The complex biological enzyme solution in step b includes endo-cellulase, xylanase and lytic polysaccharide monooxygenase, and the enzyme activity ratio of endo-cellulase, xylanase and lytic polysaccharide monooxygenase is 1-3:2-4:1, and the total enzyme activity addition amount is 15-40 U / g.

7. The preparation method according to claim 4, characterized in that, The enzyme hydrolysis reaction in step b is as follows: react at pH 5.0-6.0 and temperature 50-58℃ for 60-120 min; then adjust the pH to 4.5-5.0 and continue to react at temperature 45-50℃ for 60-120 min.

8. The method of claim 1, wherein, The alkali treatment process in step (1) is as follows: place the enzyme-treated banana pseudostem raw material in a digester, set the bath ratio to 1:15-20, the NaOH dosage is 18-22% based on the mass of the absolute dry raw material, cook at 150℃-165℃ for 50-70 min, and after the reaction is completed, cool to room temperature and wash the pulp to neutral.

9. The method of claim 1, wherein, The beating in step (2) is to beat the banana pseudostem to 28-45°SR and beat the bamboo pulp to 32-38°SR.

10. The bamboo pulp paper with high mechanical properties prepared by the preparation method of any one of claims 1-9.