A multi-functional pulp molded article and a method for manufacturing the same

Abstract

The application belongs to the technical field of intelligent packaging, and discloses a multifunctional paper pulp molded product and a preparation method thereof; the preparation method of the multifunctional paper pulp molded product comprises the following steps: preparing zanthoxylum bungeanum cyanidin and an antibacterial extract; preparing an antibacterial fiber mixed solution and an antibacterial cellulose nanocrystal solution; preparing a paper pulp molded material for freshness monitoring by using the zanthoxylum bungeanum cyanidin, the antibacterial fiber mixed solution and the antibacterial cellulose nanocrystal solution; mixing and stirring the antibacterial cellulose nanocrystal solution and a tannic acid solution to obtain an antibacterial Pickering emulsion stabilizer; mixing the antibacterial extract, an antibacterial water-phase material and the antibacterial Pickering emulsion stabilizer, and then performing ultrasonic emulsification to obtain an O / W type Pickering emulsion; and spraying the O / W type Pickering emulsion on the paper pulp molded material for freshness monitoring, and then performing drying to obtain a paper pulp molded product for freshness monitoring and antibacterial fresh-keeping; and the application can solve the problem of single function of the paper pulp molded product and food packaging material.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent packaging, and in particular to a multifunctional pulp molded product and a preparation method thereof. Background Art

[0002] As people's living standards continue to improve, their requirements for food freshness are also increasing. Seafood is favored by people because it is rich in nutrients. However, seafood products are easily affected by microorganisms during storage, transportation and sales, causing corruption and toxicity, which is harmful to human health. Therefore, the technology of antibacterial preservation and freshness monitoring during the storage, transportation and sales of seafood products has become an important issue that needs to be solved urgently.

[0003] At present, there are some reports and studies on the antibacterial preservation, shelf life extension and freshness monitoring of seafood. For example, in "A strong carboxymethyl cellulose nanocomposite material with both antibacterial and ammonia response functions and its preparation method and application" (CN115260600A), benzoic acid is used to prepare Co-MOF nanoparticles as antibacterial detection materials, and combined with carboxymethyl cellulose to prepare an intelligent indicator of the freshness changes of shrimp and other meat foods during storage. However, the preparation process of nanoparticles is complicated and the dispersion is poor, resulting in poor monitoring and antibacterial effects. In the invention patent "Preparation method and application of an antibacterial and indicator film" (CN118146546A), bacterial cellulose and pullulan polysaccharide film are used as sterilization and preservation materials. The substrate of the membrane, bamboo red fungus B, anthocyanin and alizarin are loaded onto the surface of the bacterial cellulose membrane and applied to photocatalytic antibacterial. The combination of bacterial cellulose and polysaccharide makes the film substrate have good mechanical properties. The photosensitizer bamboo red fungus B has a good antibacterial effect, but its preparation process is complicated and the cost is high, resulting in limited application. In "A starch / polyvinyl alcohol-based high-performance composite material with both antibacterial and pH-responsive functions and its preparation method and application" (CN115260603A), starch, polyvinyl alcohol, glycerol, rhein, and rod-shaped zinc oxide nanoparticles are used to prepare a composite material with antibacterial and pH-responsive properties, which is used in the field of food packaging. However, rhein has certain biological toxicity and may endanger human health when used in food testing.

[0004] It can be seen that in the patents that have been published, the antibacterial and monitoring packaging materials for seafood products face many challenges, such as complex preparation processes and poor biocompatibility, which have adverse effects on the quality of seafood products, and the antibacterial detection function is easily affected by the environment. It is impossible to accurately and timely monitor whether seafood products are spoiled, which makes it difficult for consumers to judge the freshness of food and increases the risk of eating spoiled seafood. Therefore, the development of a simple green packaging material with antibacterial properties that can prolong the freshness of seafood products and monitor whether food is spoiled has become the key to solving the problem. Summary of the Invention

[0005] The present invention aims to provide a multifunctional pulp molded product and a preparation method thereof to overcome the problems existing in the prior art. The present invention can use the agricultural crop Zanthoxylum bungeanum as a raw material, extract Zanthoxylum bungeanum anthocyanidins and an antibacterial extract through organic acid treatment and organic solvents such as ethanol, mix Zanthoxylum bungeanum fiber nanocrystals with tannic acid to prepare an antibacterial Pickering emulsion stabilizer, and mix the antibacterial extract, the antibacterial Pickering emulsion stabilizer, and an antibacterial aqueous phase material (a Chinese herbal medicine extract) to prepare an antibacterial Pickering emulsion. Then, Zanthoxylum bungeanum fiber is mixed with ramie fiber and Zanthoxylum bungeanum anthocyanidins to prepare a pulp molding material with a monitoring function. The antibacterial Pickering emulsion is then sprayed on the pulp molding material to obtain a pulp molding product with both seafood freshness monitoring and antibacterial preservation functions. The present invention aims to solve the problems of single function, lack of freshness monitoring function, and poor antibacterial effect of pulp molding products and related food packaging materials sold on the market. At the same time, the Zanthoxylum bungeanum raw material can be fully utilized, thereby improving the high-value utilization of biomass resources.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for preparing a multifunctional pulp molded product, comprising the following steps:

[0008] Step 1, preparing anthocyanidins and antibacterial extracts of Zanthoxylum bungeanum;

[0009] Step 2: preparing an antibacterial fiber mixed solution and an antibacterial cellulose nanocrystal solution;

[0010] Step 3, preparing a pulp molding material for freshness monitoring by using a mixture of anthocyanins from Zanthoxylum bungeanum, an antibacterial fiber solution, and an antibacterial cellulose nanocrystal solution;

[0011] Step 4: mixing and stirring the antibacterial cellulose nanocrystal solution and the tannic acid solution to obtain an antibacterial Pickering emulsion stabilizer;

[0012] Step 5, mixing the antibacterial extract, the antibacterial aqueous phase material and the antibacterial Pickering emulsion stabilizer and then performing ultrasonic emulsification to obtain an O / W Pickering emulsion;

[0013] Step 6: spraying the O / W Pickering emulsion onto the pulp molding material for freshness monitoring and drying the resulting pulp molding product to obtain the pulp molding product for freshness monitoring and antibacterial preservation;

[0014] Furthermore, the preparation of Zanthoxylum anthocyanidins and antibacterial extract specifically includes:

[0015] Separating the dried Zanthoxylum bungeanum seeds from the dried Zanthoxylum bungeanum pericarp, and grinding the dried Zanthoxylum bungeanum pericarp to obtain Zanthoxylum bungeanum pericarp powder;

[0016] Mixing and stirring the Zanthoxylum bungeanum pericarp powder with acid methanol, and then performing primary filtration to obtain a primary filtrate and a primary residue, mixing and stirring the primary residue with acid methanol under the same conditions, and then performing secondary filtration to obtain a secondary filtrate and a secondary residue, and then concentrating and evaporating the primary filtrate and the secondary filtrate to obtain a concentrated solution, and then freeze-drying the concentrated solution to obtain Zanthoxylum bungeanum anthocyanidin;

[0017] Adding the dried Zanthoxylum bungeanum seeds into an organic solvent to perform reaction, and obtaining a reaction product, filtering the reaction product to obtain a product filtrate and a product residue, and then standing and separating the product filtrate to obtain an upper organic layer, and then performing vacuum distillation on the upper organic layer to obtain an antibacterial type extraction solution;

[0018] Further, the particle size of the Zanthoxylum bungeanum pericarp powder is 60-120 mesh; the mass ratio of the Zanthoxylum bungeanum pericarp powder to acid methanol is 1:(20-30); the acid methanol is obtained by mixing an organic carboxylic acid and methanol at a volume ratio of 5:1, wherein the organic carboxylic acid includes one of tartaric acid, acetic acid and trifluoroacetic acid; the temperature for mixing and stirring is 50-60 ℃, and the time is 1-2 h; the temperature for freeze-drying is -50 ℃, and the time is 48 h;

[0019] The mass ratio of the Zanthoxylum bungeanum seeds to the organic solvent is 1:(5-8); the organic solvent includes one or a mixture of several of methanol, ethanol and acetone; the temperature for reaction is 40-50 ℃, and the time is 2 h; the temperature for vacuum distillation is 50 ℃, and the time is 1 h;

[0020] Further, the preparation of the antibacterial type fiber mixture solution and the antibacterial type cellulose nanocrystal solution specifically includes:

[0021] Adding bleached Zanthoxylum bungeanum wood fibers and bleached ramie fibers into water to perform mixing, and obtaining an antibacterial type fiber mixture solution;

[0022] Mixing and stirring the antibacterial type fiber mixture solution with a hydrochloric acid solution, and then adding deionized water to perform centrifugal washing, and obtaining a suspension, and then adjusting the pH value of the suspension until neutral, and obtaining an antibacterial type cellulose nanocrystal solution;

[0023] Further, the mass ratio of the bleached Zanthoxylum bungeanum wood fibers, the bleached ramie fibers and the water is 10:(1-5):(100-150); the mass ratio of the antibacterial type fiber mixture solution to the hydrochloric acid solution is 1:(10-20); the mass concentration of the hydrochloric acid solution is 50-70%; the temperature for mixing and stirring is 40 ℃, and the time is 1-2 h; the rotation speed for centrifugal washing is 3000-4000 rpm, and the time is 10-20 min;

[0024] Further, the paper pulp molding material for freshness monitoring prepared by the Zanthoxylum bungeanum anthocyanins, bacteriostatic fiber mixed solution and bacteriostatic cellulose nanocrystal solution specifically comprises the following steps:

[0025] The Zanthoxylum bungeanum anthocyanins, bacteriostatic fiber mixed solution and bacteriostatic cellulose nanocrystal solution are mixed to obtain a mixed solution, and saturated sodium bicarbonate solution is added to the mixed solution to obtain a mixed slurry;

[0026] After the mixed gas of carbon dioxide and air is introduced into the mixed slurry, bubbles are generated, and then a stepwise pulse hot pressing process is used for drying to obtain the paper pulp molding material for freshness monitoring;

[0027] Further, the mass ratio of the Zanthoxylum bungeanum anthocyanins, bacteriostatic fiber mixed solution and bacteriostatic cellulose nanocrystal solution is (0.005-0.01):1:(0.1-0.5), and the mass ratio of the bacteriostatic fiber mixed solution and saturated sodium bicarbonate solution is 1:(5-8);

[0028] The volume of the mixed gas introduced into each kilogram of the mixed slurry is 400-800 mL, and the volume ratio of carbon dioxide to air in the mixed gas is 1:5; the stepwise pulse hot pressing process for drying comprises a first stage, a second stage and a third stage, wherein the hot pressing temperature of the first stage is 40-60 ℃, the hot pressing pressure is 5 MPa, and the hot pressing time is 1-2 min, the hot pressing temperature of the second stage is 65-85 ℃, the hot pressing pressure is 2 MPa, and the hot pressing time is 5-10 min, and the pressure is released once every 1 min, and the hot pressing temperature of the third stage is 90-110 ℃, the hot pressing pressure is normal pressure, and the hot pressing time is 2-5 min;

[0029] Further, the mass ratio of the bacteriostatic cellulose nanocrystal solution and tannic acid solution is 1:(0.1-1), and the mixing and stirring treatment time is 1-2 h;

[0030] The mass concentration of the antibacterial water phase material is 0.1-0.3%, and the antibacterial water phase material comprises one of tea tree extract, rosemary extract and honeysuckle extract; the mass ratio of the bacteriostatic extract, antibacterial water phase material and bacteriostatic Pickering emulsion stabilizer is 1:(2-4):(0.004-0.006); the ultrasonic emulsification power is 200-400 W, the rotation speed is 12000 rpm, and the time is 3-5 min;

[0031] Further, the spraying thickness is 5-10 μm, the drying temperature is 40 ℃, and the drying time is 1-2 h.

[0032] In a second aspect, the application further provides a multifunctional paper pulp molding product prepared based on the above multifunctional paper pulp molding product preparation method.

[0033] The above technical solution has the following advantages or beneficial effects:

[0034] In the first aspect, the present invention provides a method for preparing a multifunctional pulp molded product, which uses common Sichuan pepper as the main raw material, and subjecting Sichuan pepper fruits and Sichuan pepper wood to a series of treatments to obtain pulp molded products for food monitoring and antibacterial preservation. Sichuan pepper is used to monitor and protect the freshness of food, thereby realizing high-value utilization of resources. The present invention first uses Sichuan pepper seeds to obtain an antibacterial extract, and Sichuan pepper peels are prepared into Sichuan pepper anthocyanins with monitoring functions. Then, Sichuan pepper anthocyanins and Sichuan pepper wood fibers are mixed with ramie fibers using a foam molding process to prepare a pulp molding material with high bulk. Nanocrystals are obtained by treating the fiber mixture, and the prepared Pickering emulsion has three-phase antibacterial properties. The emulsion is finally sprayed on pulp molding materials. Compared with traditional food packaging materials, it has improved antibacterial effects and safety, reduced the potential dangers of food spoilage to human health, and has a wide range of applications. The pulp molding products make full use of the raw materials of Sichuan pepper, improving the high-value utilization of Sichuan pepper. Not only can the pulp molding products be used as buffer materials in the food transportation process, but they can also be used to monitor the freshness of food. At the same time, they have excellent antibacterial and fresh-keeping effects, extending the storage time and shelf life of food.

[0035] Furthermore, the present invention utilizes anthocyanin, an ingredient extracted from the peel of Zanthoxylum bungeanum, as an indicator for detecting the freshness of food. Anthocyanin-3-O-rutinoside and cyanidin-3-O-glucoside contained in the peel of Zanthoxylum bungeanum are the most critical compounds for presenting the color of the peel of Zanthoxylum bungeanum. Zanthoxylum bungeanum anthocyanin is obtained by impregnating the peel of Zanthoxylum bungeanum with an organic solvent. As the external acid-base environment changes, the structure of Zanthoxylum bungeanum anthocyanin changes, thereby producing different color responses, achieving a colorimetric effect that can be identified by the naked eye; at the same time, Zanthoxylum bungeanum seeds are used to obtain an antibacterial extract, which mainly utilizes terpenes and hydrocarbon oxygen-containing organic compounds in the seeds of Zanthoxylum bungeanum to achieve an antibacterial effect by destroying the cell walls of bacteria and inhibiting cell respiration metabolism, thereby causing bacterial death.

[0036] Furthermore, the present invention uses bleached prickly ash fiber and bleached ramie fiber to prepare an antibacterial fiber mixture, wherein the prickly ash fiber itself contains alkaloid components such as prickly ash, and the ramie fiber contains trace elements such as dapoxetine, purine, and pyrimidine, and has natural antibacterial properties. Ramie fiber is mixed with prickly ash fiber to achieve the extension of food storage time; by adding a certain amount of ramie fiber to the prickly ash fiber, the ramie fiber is mainly used to control the stability of bubbles introduced into the mixed gas and improve the internal bonding strength and ring pressure strength of the pulp molding material. Since the ramie fiber is long and light in weight, when the mixed gas is introduced, the bubbles generated can support the fibers, so that the fibers can be better dispersed, and the bubbles advance the distance between the fibers, increase the hydrogen bonding between the fibers, and improve the internal bonding strength and ring pressure strength of the pulp molding material. In addition, the micropores on the surface of the ramie fiber help to capture and stabilize bubbles, provide a physical barrier for the bubbles, and reduce the merging and rupture of the bubbles.

[0037] Furthermore, the present invention uses sodium bicarbonate as an inorganic foaming material in the foam molding process, utilizes a mixture of air and carbon dioxide to obtain a large number of bubbles in an antibacterial fiber mixture, and then mixes with a saturated sodium bicarbonate solution. The mixture is used to generate bubbles and overlaps between the fibers. At the same time, due to the introduction of carbon dioxide, the saturated sodium bicarbonate solution reaches an oversaturated state, thereby recrystallizing between the fibers and the bubble liquid film to obtain sodium bicarbonate crystals of micrometer or smaller size. Such crystals can evenly release carbon dioxide gas in the subsequent drying process to achieve pore formation, and ultimately achieve high bulk thickness of the pulp molding material; the present invention adopts a stepped pulse hot pressing process during the drying process, which can prevent the sodium bicarbonate from decomposing too quickly and causing excessive pores. The pores are broken, thereby obtaining a pulp molding material with a smaller and uniform pore size, and improving the stiffness and ring crush strength of the pulp molded products. The specific operation is to make all the saturated sodium bicarbonate crystallize and precipitate in the first stage and maintain the structural stability of the pulp molding material under high pressure. In the second stage, the sodium bicarbonate is decomposed by heat to produce carbon dioxide to obtain pores, and the pressure is released once every one minute to release the gas. This process can effectively avoid the problems of fiber bridging and uneven pores caused by gas accumulation. The third stage is hot pressing at high temperature and normal pressure. The main purpose is to remove water and shape. In this stage, since high-temperature fiber collapse will not occur after the hot pressing process in the first two stages, the pulp molding material can be obtained under normal pressure.

[0038] Furthermore, the main antibacterial property of the present invention is the oil phase antibacterial extract extracted from Zanthoxylum bungeanum seeds. The antibacterial extract has good antibacterial and antioxidant properties, but it is volatile and difficult to use directly. Therefore, the antibacterial aqueous phase material is prepared by using tannic acid composite cellulose nanocrystals as stabilizing particles (i.e., antibacterial Pickering emulsion stabilizer) and using Chinese herbal extracts including tea tree extract, rosemary extract, honeysuckle extract, etc. in the aqueous phase.

[0039] Furthermore, an O / W Pickering emulsion is prepared by compounding an oil-phase antibacterial extract, an antibacterial aqueous phase material, and an antibacterial Pickering emulsion stabilizer. Tannic acid contains a large number of hydroxyl groups that can combine with cellulose nanocrystals to form hydrogen bonds to enhance stabilization and form a more ordered emulsion network structure. In addition, the phenolic structure of tannic acid has a certain antibacterial effect. Therefore, the aqueous phase, oil phase, and particle stabilizing phase in the O / W Pickering emulsion prepared by the present invention all have antibacterial functions, and the prepared Pickering emulsion has three-phase antibacterial properties.

[0040] In a second aspect, the present invention also provides a multifunctional pulp molded product. The present invention combines the high bulk and high stiffness pulp molded product prepared by papermaking technology, has a large number of pore structures and excellent mechanical properties, and is biodegradable. Ramie fiber and Sichuan pepper fiber are used as the main materials to obtain a pulp molded product with certain antibacterial properties. Due to the pore structure of the pulp mold, once the food becomes corrupted, the gas released by it can better contact the Sichuan pepper anthocyanin response detection unit, making the detection of food freshness more sensitive. In addition, other raw materials of Sichuan pepper crops are used to prepare a Pickering emulsion with three-phase antibacterial properties. When sprayed on one side of the pulp molding material, the Pickering emulsion breaks due to gravity and electrostatic adsorption, and the antibacterial components in the aqueous phase material quickly combine with the internal fibers of the pulp molding, adsorbing the antibacterial substances on the fibers. The oil phase covers the surface of the pulp molded product through hydrogen bonds with the hydroxyl groups of the fibers, obtaining a pulp molded product coating with a Janus structure. The two sides of the Janus film structure exhibit different properties. The side sprayed with the Pickering emulsion exhibits hydrophobicity due to the oil phase deposited on the surface of the pulp molding material, while the other side exhibits hydrophilicity, thereby improving the application scenarios and application value of the pulp molded products. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic flow chart of a method for preparing a multifunctional pulp molded product of the present invention;

[0042] Figure 2 This is a schematic structural diagram of a multifunctional pulp molded product according to Example 1 of the present invention;

[0043] Figure 3 This is a side view of the multifunctional pulp molded product according to Example 1 of the present invention;

[0044] Figure 4 This is a rear view of the multifunctional pulp molded product according to Example 1 of the present invention;

[0045] Figure 5 This is a schematic diagram of shrimp monitoring according to Example 1 of the present invention. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain the present invention rather than to limit it.

[0047] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0049] Example 1:

[0050] See also Figure 1 The present invention provides a method for preparing a multifunctional pulp molded product, comprising the following steps:

[0051] Step 1: Prepare Zanthoxylum anthocyanidins and antibacterial extract:

[0052] Separating the dried Zanthoxylum bungeanum seeds and Zanthoxylum bungeanum peels, and grinding the dried Zanthoxylum bungeanum peels to obtain Zanthoxylum bungeanum peel powder of 60-80 mesh;

[0053] 3 g of Zanthoxylum bungeanum peel powder was placed in a three-necked flask, and then 50 g of acetic acid and 10 g of methanol solution were added. The mixture was stirred at 50°C for 2 h and filtered once to obtain a primary filtrate and a primary filter residue, respectively. The primary filter residue was added to the three-necked flask again, and 50 g of acetic acid and 10 g of methanol solution were added again. The mixture was stirred at 50°C for 2 h to obtain a secondary filtrate and a secondary filter residue, respectively. The primary filtrate and the secondary filtrate were then rotary evaporated at 50°C for 1 h to obtain a concentrated solution. The concentrated solution was freeze-dried at a cold trap coil temperature below -50°C for 48 h to obtain Zanthoxylum bungeanum anthocyanins.

[0054] 5 g of sun-dried Zanthoxylum bungeanum seeds were placed in a three-necked flask, added to 25 g of methanol solution and reacted at 40°C for 2 h to obtain a reaction product. The reaction product was filtered to obtain a product filtrate and a product residue, respectively. The product filtrate was allowed to stand for separation to obtain an upper organic layer. The upper organic layer was rotary evaporated at 50°C for 1 h to obtain an antibacterial extract.

[0055] Step 2: Prepare antibacterial fiber mixed solution and antibacterial cellulose nanocrystal solution:

[0056] In a three-necked flask, 10 g of bleached Zanthoxylum fiber, 1 g of bleached ramie fiber, and 100 g of water were added and mixed to obtain an antibacterial fiber mixture. 5 g of the antibacterial fiber mixture was mixed with 50 g of hydrochloric acid solution at 40 °C and stirred for 2 h. Deionized water was then added to terminate the acid hydrolysis reaction. The mass concentration of the hydrochloric acid solution was 50%. The mixture was centrifuged and washed at 3000 rpm for 20 min to obtain a suspension. The pH value of the suspension was adjusted to neutral to obtain an antibacterial cellulose nanocrystal solution.

[0057] Step 3: Prepare a pulp molding material for freshness monitoring by using anthocyanins from Zanthoxylum bungeanum, an antibacterial fiber mixture, and an antibacterial cellulose nanocrystal solution:

[0058] 30 g of antibacterial fiber mixture was added to a beaker, and then 3 g of antibacterial cellulose nanocrystal solution and 0.15 g of anthocyanin from Zanthoxylum bungeanum were added and stirred evenly to obtain a mixed solution. 150 g of saturated sodium bicarbonate was added to the mixed solution to obtain a mixed slurry. The pulp foam molding process was used to introduce 12 ml of a mixture of carbon dioxide and air into the mixed slurry through an injection mixer to generate bubbles, wherein the mixed gas contained 2 ml of carbon dioxide and 10 ml of air, and the bubble size was 50-200 μm in diameter. After stirring for 2 h, the mixture was poured into a film-forming plate and placed in a pulse dryer for drying using a step-by-step pulse hot pressing process. The step-by-step pulse hot pressing process for drying includes the first, second and third stages, wherein the hot pressing temperature of the first stage is set to 40 °C, the pressure is 5 MPa, and the time is 2 min; the hot pressing temperature of the second stage is set to 65 °C, the pressure is 2 MPa, and the time is 10 min, and the pressure is released once every 1 min to release the gas; the hot pressing temperature of the third stage is set to 90 ℃, the hot pressing pressure is normal pressure, and the time is 5 min to obtain the pulp molding material with freshness monitoring function;

[0059] Step 4: 1 g of the antibacterial cellulose nanocrystal solution and 0.1 g of the tannic acid solution were mixed and stirred for 1 hour to obtain an antibacterial Pickering emulsion stabilizer, and the antibacterial Pickering emulsion stabilizer was stored at 4° C. for later use;

[0060] Step 5: 1 g of the antibacterial extract, 2 g of the tea tree extract, and 0.004 g of an antibacterial Pickering emulsion stabilizer were mixed and ultrasonically emulsified at 12,000 rpm and a power of 200 W for 5 min, wherein the mass concentration of the tea tree extract was 0.1%, to obtain an O / W Pickering emulsion;

[0061] Step 6: Spray the O / W Pickering emulsion onto the pulp molded material for freshness monitoring and dry it at 40°C for 1 hour. The spraying thickness is 5 μm. After the water phase disappears, the antibacterial material contained in the water phase combines with the pulp molded fibers and adsorbs on the fibers, while the oil phase remains on the surface of the pulp molded material to obtain a hydrophobic coating. Finally, a pulp molded product with a Janus structure and different hydrophobicity on both sides is obtained. Figure 2-Figure 4 , which is a pulp molded product that has both food freshness monitoring and antibacterial preservation functions.

[0062] The mechanical strength index of the pulp molded product obtained in Example 1 is shown in Table 1. The pulp molded product obtained in Example 1 is used to hold shrimps. Figure 5 After packaging, the pulp molded product was placed at room temperature of 20°C for 0 hours. It was observed that the pulp molded product was light yellow; after 48 hours, the color of the pulp molded product turned yellow, indicating that the shrimp had slightly decomposed; after 5 days, the pulp molded product turned yellow-green, and the shrimp had also seriously decomposed; the pulp molded product in Example 1 was cut and placed in a bacterial culture dish to test the antibacterial effect. It was found that the pulp molded product had an inhibition rate of 96.21% on Staphylococcus aureus and an inhibition rate of 98.87% on Escherichia coli.

[0063] Example 2:

[0064] See also Figure 1 The present invention provides a method for preparing a multifunctional pulp molded product, comprising the following steps:

[0065] Step 1: Prepare Zanthoxylum anthocyanidins and antibacterial extract:

[0066] Separating the dried Zanthoxylum bungeanum seeds and Zanthoxylum bungeanum peels, and grinding the dried Zanthoxylum bungeanum peels to obtain Zanthoxylum bungeanum peel powder of 80-100 mesh;

[0067] 6 g of Zanthoxylum bungeanum peel powder was placed in a three-necked flask, and then 120 g of tartaric acid and 24 g of methanol solution were added. The mixture was stirred at 54 °C for 100 min and filtered once to obtain a primary filtrate and a primary filter residue, respectively. The primary filter residue was added to the three-necked flask again, and 120 g of tartaric acid and 24 g of methanol solution were added again. The mixture was stirred at 54 °C for 100 min to obtain a secondary filtrate and a secondary filter residue, respectively. The primary filtrate and the secondary filtrate were then rotary evaporated at 50 °C for 1 h to obtain a concentrated solution. The concentrated solution was freeze-dried at a cold trap coil temperature below -50 °C for 48 h to obtain Zanthoxylum bungeanum anthocyanins.

[0068] 10 g of sun-dried Zanthoxylum bungeanum seeds were placed in a three-necked flask, added to 60 g of ethanol solution and reacted at 43 °C for 2 h to obtain a reaction product. The reaction product was filtered to obtain a product filtrate and a product residue, respectively. The product filtrate was allowed to stand for separation to obtain an upper organic layer. The upper organic layer was rotary evaporated at 50 °C for 1 h to obtain an antibacterial extract.

[0069] Step 2: Prepare antibacterial fiber mixed solution and antibacterial cellulose nanocrystal solution:

[0070] 15 g of bleached Zanthoxylum fiber, 3 g of bleached ramie fiber, and 180 g of water were added to a three-necked flask and mixed to obtain an antibacterial fiber mixture. 10 g of the antibacterial fiber mixture was mixed with 140 g of hydrochloric acid solution at 40 °C and stirred for 100 min. Deionized water was then added to terminate the acid hydrolysis reaction. The mass concentration of the hydrochloric acid solution was 60%. The mixture was centrifuged and washed at 3400 rpm for 18 min to obtain a suspension. The pH value of the suspension was adjusted to neutral to obtain an antibacterial cellulose nanocrystal solution.

[0071] Step 3: Prepare a pulp molding material for freshness monitoring by using anthocyanins from Zanthoxylum bungeanum, an antibacterial fiber mixture, and an antibacterial cellulose nanocrystal solution:

[0072] 35 g of antibacterial fiber mixture was added to a beaker, and then 7 g of antibacterial cellulose nanocrystal solution and 0.21 g of anthocyanin from Zanthoxylum bungeanum were added and stirred evenly to obtain a mixed solution. 210 g of saturated sodium bicarbonate was added to the mixed solution to obtain a mixed slurry. The pulp foam molding process was used to introduce 21 ml of a mixture of carbon dioxide and air into the mixed slurry through an injection mixer to generate bubbles, wherein the mixed gas contained 3.5 ml of carbon dioxide and 17.5 ml of air, and the bubble size was 50 ~ 200 μm in diameter. After stirring for 2 h, the mixture was poured into a film forming plate and placed in a pulse dryer for drying using a step-by-step pulse hot pressing process. The step-by-step pulse hot pressing process for drying included the first stage, the second stage and the third stage, wherein the hot pressing temperature of the first stage was set to 44 ° C, the pressure was 5 MPa, and the time was 100 s, the hot pressing temperature of the second stage was set to 75 ° C, the pressure was 2 MPa, and the time was 8 min, and each time after 1 min, one pressure relief is required to release the gas, and the hot pressing temperature of the third stage is 100 ℃, the hot pressing pressure is normal pressure, and the time is 4 min to obtain a pulp molding material with freshness monitoring function;

[0073] Step 4: 3 g of the antibacterial cellulose nanocrystal solution and 1.2 g of the tannic acid solution were mixed and stirred for 80 minutes to obtain an antibacterial Pickering emulsion stabilizer, and the antibacterial Pickering emulsion stabilizer was stored at 4° C. for later use;

[0074] Step 5: 3 g of the antibacterial extract, 7.5 g of the rosemary extract, and 0.0135 g of the antibacterial Pickering emulsion stabilizer were mixed and ultrasonically emulsified at 12,000 rpm and 300 W for 4 min, wherein the mass concentration of the rosemary extract was 0.2%, to obtain an O / W Pickering emulsion;

[0075] Step six: spray the O / W Pickering emulsion onto the pulp molded material used for freshness monitoring and dry it at 40°C for 80 min. The spraying thickness is 6 μm. After the water phase disappears, the antibacterial material contained in the water phase combines with the pulp molded fibers and adsorbs on the fibers, while the oil phase remains on the surface of the pulp molded material to obtain a hydrophobic coating. Finally, a pulp molded product with a Janus structure and different hydrophobicity on both sides is obtained, which is a pulp molded product with both food freshness monitoring and antibacterial preservation functions.

[0076] The mechanical strength indexes of the pulp molded product obtained in Example 2 are shown in Table 1. The pulp molded product obtained in Example 2 was used to hold shrimp, packaged, and placed at room temperature of 20°C for three days before the food began to spoil, and the color of the pulp molded product changed, indicating that the pulp molded material can extend the shelf life of food and monitor the freshness of food. The pulp molded product obtained in Example 2 was used to hold shrimp, packaged, and placed at -5°C for 0 hours. It was observed that the pulp molded product was light yellow. After 7 days, the color of the pulp molded product turned yellow, indicating that the shrimp had slightly spoiled. After 10 days, the pulp molded product turned yellow-green, indicating that the shrimp had also seriously spoiled. A cut portion of the pulp molded product in Example 2 was placed in a bacterial culture dish to test the antibacterial effect. It was found that the pulp molded product had an inhibition rate of 98.99% against Staphylococcus aureus and an inhibition rate of 99.58% against Escherichia coli.

[0077] Example 3:

[0078] See also Figure 1 The present invention provides a method for preparing a multifunctional pulp molded product, comprising the following steps:

[0079] Step 1: Prepare Zanthoxylum anthocyanidins and antibacterial extract:

[0080] Separating the sun-dried Zanthoxylum bungeanum seeds and Zanthoxylum bungeanum peels, and grinding the sun-dried Zanthoxylum bungeanum peels to obtain Zanthoxylum bungeanum peel powder of 100-120 mesh;

[0081] 9 g of Zanthoxylum bungeanum peel powder was placed in a three-necked flask, and then 210 g of trifluoroacetic acid and 42 g of methanol solution were added. The mixture was stirred at 58 °C for 80 min and filtered once to obtain a primary filtrate and a primary filter residue, respectively. The primary filter residue was added to the three-necked flask again, and 210 g of trifluoroacetic acid and 42 g of methanol solution were added again. The mixture was stirred at 58 °C for 80 min to obtain a secondary filtrate and a secondary filter residue, respectively. The primary filtrate and the secondary filtrate were then rotary evaporated at 50 °C for 1 h to obtain a concentrated solution. The concentrated solution was freeze-dried at a cold trap coil temperature below -50 °C for 48 h to obtain Zanthoxylum bungeanum anthocyanins.

[0082] 15 g of sun-dried Zanthoxylum bungeanum seeds were placed in a three-necked flask, added to 105 g of acetone solution and reacted at 47 °C for 2 h to obtain a reaction product. The reaction product was filtered to obtain a product filtrate and a product residue, respectively. The product filtrate was allowed to stand for separation to obtain an upper organic layer. The upper organic layer was rotary evaporated at 50 °C for 1 h to obtain an antibacterial extract.

[0083] Step 2: Prepare antibacterial fiber mixed solution and antibacterial cellulose nanocrystal solution:

[0084] 15 g of bleached Zanthoxylum fiber, 6 g of bleached ramie fiber, and 210 g of water were added to a three-necked flask and mixed to obtain an antibacterial fiber mixture. 8 g of the antibacterial fiber mixture was mixed with 128 g of hydrochloric acid solution at 40 °C and stirred for 80 min. Deionized water was then added to terminate the acid hydrolysis reaction. The mass concentration of the hydrochloric acid solution was 70%. The mixture was centrifuged and washed at 3800 rpm for 15 min to obtain a suspension. The pH value of the suspension was adjusted to neutral to obtain an antibacterial cellulose nanocrystal solution.

[0085] Step 3: Prepare a pulp molding material for freshness monitoring by using anthocyanins from Zanthoxylum bungeanum, an antibacterial fiber mixture, and an antibacterial cellulose nanocrystal solution:

[0086] 20 g of antibacterial fiber mixture was added to a beaker, and then 8 g of antibacterial cellulose nanocrystal solution and 0.16 g of anthocyanin from Zanthoxylum bungeanum were added and stirred evenly to obtain a mixed solution. 140 g of saturated sodium bicarbonate was added to the mixed solution to obtain a mixed slurry. The pulp foam molding process was used to introduce 15 ml of a mixture of carbon dioxide and air into the mixed slurry through an injection mixer to generate bubbles, wherein the mixed gas contained 2.5 ml of carbon dioxide and 12.5 ml of air, and the bubble size was 50 ~ 200 μm in diameter. After stirring for 2 h, the mixture was poured into a film forming plate and placed in a pulse dryer for drying using a step-by-step pulse hot pressing process. The step-by-step pulse hot pressing process for drying includes the first stage, the second stage and the third stage. The hot pressing temperature of the first stage is set to 50 ° C, the pressure is 5 MPa, and the time is 80 s. The hot pressing temperature of the second stage is 80 ° C, the pressure is 2 MPa, and the time is 6 min. After every 1 min, the pressure is released once to release the gas. The hot pressing temperature of the third stage is 105 ℃, the hot pressing pressure is normal pressure, and the time is 3 min to obtain the pulp molding material with freshness monitoring function;

[0087] Step 4: 2 g of the antibacterial cellulose nanocrystal solution and 1.6 g of the tannic acid solution were mixed and stirred for 100 minutes to obtain an antibacterial Pickering emulsion stabilizer, and the antibacterial Pickering emulsion stabilizer was stored at 4° C. for later use;

[0088] Step 5: 2 g of the antibacterial extract, 7 g of the honeysuckle extract, and 0.01 g of an antibacterial Pickering emulsion stabilizer were mixed and ultrasonically emulsified at 12,000 rpm and 400 W for 3 min, wherein the mass concentration of the honeysuckle extract was 0.3%, to obtain an O / W Pickering emulsion;

[0089] Step six: spray the O / W Pickering emulsion onto the pulp molded material used for freshness monitoring and dry it at 40°C for 100 min. The spraying thickness is 8 μm. After the water phase disappears, the antibacterial material contained in the water phase combines with the pulp molded fibers and adsorbs on the fibers, while the oil phase remains on the surface of the pulp molded material to obtain a hydrophobic coating. Finally, a pulp molded product with a Janus structure and different hydrophobicity on both sides is obtained, which is a pulp molded product with both food freshness monitoring and antibacterial preservation functions.

[0090] The mechanical strength indexes of the pulp molded product obtained in Example 3 are shown in Table 1. The pulp molded product obtained in Example 3 was used to hold shrimp, and after being packaged, it was placed at a room temperature of 20°C for 3 days before the food became spoiled, and the color of the pulp molded product changed, indicating that the pulp molded material can extend the shelf life of food and monitor the freshness of food. The pulp molded product obtained in Example 3 was used to hold salmon, and after being packaged, it was placed at a room temperature of 20°C for 0 hours. It was observed that the pulp molded product was light yellow; after 48 hours, the color of the pulp molded product turned yellow, indicating that the salmon had slightly spoiled; after 5 days, the pulp molded product turned yellow-green, indicating that the salmon had also seriously spoiled. A cut portion of the pulp molded product in Example 3 was placed in a bacterial culture dish to test the antibacterial effect. It was found that the pulp molded product had an inhibition rate of 97.79% on Staphylococcus aureus and an inhibition rate of 99.46% on Escherichia coli.

[0091] Embodiment 4:

[0092] See also Figure 1 The present invention provides a method for preparing a multifunctional pulp molded product, comprising the following steps:

[0093] Step 1: Prepare Zanthoxylum anthocyanidins and antibacterial extract:

[0094] Separating the dried Zanthoxylum bungeanum seeds and Zanthoxylum bungeanum peels, and grinding the dried Zanthoxylum bungeanum peels to obtain Zanthoxylum bungeanum peel powder of 80-100 mesh;

[0095] 12 g of Zanthoxylum bungeanum peel powder was placed in a three-necked flask, and then 300 g of acetic acid and 60 g of methanol solution were added. The mixture was stirred at 60°C for 1 hour and filtered once to obtain a primary filtrate and a primary filter residue, respectively. The primary filter residue was added to the three-necked flask again, and 300 g of acetic acid and 60 g of methanol solution were added again. The mixture was stirred at 60°C for 1 hour to obtain a secondary filtrate and a secondary filter residue, respectively. The primary filtrate and the secondary filtrate were then rotary evaporated at 50°C for 1 hour to obtain a concentrated solution. The concentrated solution was freeze-dried at a cold trap coil temperature below -50°C for 48 hours to obtain Zanthoxylum bungeanum anthocyanins.

[0096] 20 g of sun-dried Zanthoxylum bungeanum seeds were placed in a three-necked flask, and 80 g of ethanol and 80 g of acetone solution were added to react at 50°C for 2 h to obtain a reaction product. The reaction product was filtered to obtain a product filtrate and a product residue, respectively. The product filtrate was allowed to stand for separation to obtain an upper organic layer. The upper organic layer was rotary evaporated at 50°C for 1 h to obtain an antibacterial extract.

[0097] Step 2: Prepare antibacterial fiber mixed solution and antibacterial cellulose nanocrystal solution:

[0098] 20 g of bleached Zanthoxylum fiber, 10 g of bleached ramie fiber, and 300 g of water were added to a three-necked flask and mixed to obtain an antibacterial fiber mixture. 12 g of the antibacterial fiber mixture was mixed with 240 g of hydrochloric acid solution at 40 °C and stirred for 1 h, followed by addition of deionized water to terminate the acid hydrolysis reaction. The mass concentration of the hydrochloric acid solution was 60%, and the mixture was centrifuged and washed at 4000 rpm for 10 min to obtain a suspension. The pH value of the suspension was adjusted to neutral to obtain an antibacterial cellulose nanocrystal solution.

[0099] Step 3: Prepare a pulp molding material for freshness monitoring by using anthocyanins from Zanthoxylum bungeanum, an antibacterial fiber mixture, and an antibacterial cellulose nanocrystal solution:

[0100] 10 g of antibacterial fiber mixture was added to a beaker, and then 5 g of antibacterial cellulose nanocrystal solution and 0.1 g of anthocyanin from Zanthoxylum bungeanum were added and stirred evenly to obtain a mixed solution. 80 g of saturated sodium bicarbonate was added to the mixed solution to obtain a mixed slurry. The pulp foam molding process was used to introduce 8 ml of a mixture of carbon dioxide and air into the mixed slurry through an injection mixer to generate bubbles, wherein the mixed gas contained 1.4 ml of carbon dioxide and 7 ml of air, and the bubble size was 50 ~ 200 μm in diameter. After stirring for 2 h, it was poured into a film forming plate and placed in a pulse dryer for drying using a step-by-step pulse hot pressing process. The step-by-step pulse hot pressing process for drying includes the first stage, the second stage and the third stage. The hot pressing temperature of the first stage is set to 60 ° C, the pressure is 5 MPa, and the time is 1 min. The hot pressing temperature of the second stage is 85 ° C, the pressure is 2 MPa, and the time is 5 min. After every 1 min, the pressure is released once to release the gas. The hot pressing temperature of the third stage is 110 ℃, the hot pressing pressure is normal pressure, and the time is 2 min to obtain the pulp molding material with freshness monitoring function;

[0101] Step 4: 4 g of the antibacterial cellulose nanocrystal solution and 4 g of the tannic acid solution were mixed and stirred for 2 h to obtain an antibacterial Pickering emulsion stabilizer, and the antibacterial Pickering emulsion stabilizer was stored at 4° C. for later use;

[0102] Step 5: 4 g of the antibacterial extract, 16 g of the tea tree extract, and 0.024 g of an antibacterial Pickering emulsion stabilizer were mixed and ultrasonically emulsified at 12,000 rpm and 300 W for 4 min, wherein the mass concentration of the tea tree extract was 0.2%, to obtain an O / W Pickering emulsion;

[0103] Step six: spray the O / W Pickering emulsion onto the pulp molded material used for freshness monitoring and dry it at 40°C for 2 hours. The spraying thickness is 10 μm. After the water phase disappears, the antibacterial material contained in the water phase combines with the pulp molded fibers and adsorbs on the fibers, while the oil phase remains on the surface of the pulp molded material to obtain a hydrophobic coating. Finally, a pulp molded product with a Janus structure and different hydrophobicity on both sides is obtained, which is a pulp molded product with both food freshness monitoring and antibacterial preservation functions.

[0104] The mechanical strength indexes of the pulp molded product obtained in Example 4 are shown in Table 1. The pulp molded product obtained in Example 4 was used to hold shrimp, and after being packaged, it was placed at room temperature of 20°C for 3 days before the food became spoiled, and the color of the pulp molded product changed, indicating that the pulp molded material can extend the shelf life of food and monitor the freshness of food. The pulp molded product obtained in Example 4 was used to hold salmon, and after being packaged, it was placed at -5°C for 0 hours. It was observed that the pulp molded product was light yellow; after 7 days, the color of the pulp molded product turned yellow, indicating that the salmon had slightly spoiled; after 10 days, the pulp molded product turned yellow-green, indicating that the salmon had also seriously spoiled. A cut portion of the pulp molded product in Example 4 was placed in a bacterial culture dish to test the antibacterial effect. It was found that the pulp molded product had an inhibition rate of 99.68% against Staphylococcus aureus and an inhibition rate of 99.99% against Escherichia coli.

[0105] Table 1 Performance indicators of pulp molded products

[0106]

[0107] The relationship between pulp molded products and food freshness is shown in Table 2:

[0108] Table 2 Relationship between pulp molded products and food freshness

[0109]

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a multifunctional pulp molded product, characterized in that: The following steps are involved: Preparation of anthocyanins and an antibacterial extract of Zanthoxylum bungeanum, wherein the antibacterial extract is prepared by using Zanthoxylum bungeanum seeds and an organic solvent, wherein the mass ratio of the Zanthoxylum bungeanum seeds to the organic solvent is 1:(5-8), and the organic solvent comprises a mixed solution of one or more of methanol, ethanol, and acetone; An antibacterial fiber mixture and an antibacterial cellulose nanocrystal solution are prepared, wherein the antibacterial fiber mixture is prepared by bleaching Zanthoxylum fiber, bleaching ramie fiber and water, and the antibacterial cellulose nanocrystal solution is prepared by the antibacterial fiber mixture, wherein the mass ratio of the bleached Zanthoxylum fiber, the bleached ramie fiber and water is 10:(1-5):(100-150); A pulp molding material for freshness monitoring is prepared by using anthocyanidins from Zanthoxylum bungeanum, an antibacterial fiber mixed solution and an antibacterial cellulose nanocrystal solution. The method comprises the following steps: mixing anthocyanidins from Zanthoxylum bungeanum, an antibacterial fiber mixed solution and an antibacterial cellulose nanocrystal solution to obtain a mixed solution, adding a saturated sodium bicarbonate solution to the mixed solution to obtain a mixed slurry; introducing a mixture of carbon dioxide and air into the mixed slurry to generate bubbles, and then drying the mixture using a step-by-step pulse hot pressing process to obtain a pulp molding material for freshness monitoring; the mass ratio of the anthocyanidins from Zanthoxylum bungeanum, the antibacterial fiber mixed solution and the antibacterial cellulose nanocrystal solution is (0.005-0.01): 1: (0.1-0.5); the mass ratio of the antibacterial fiber mixed solution and the saturated sodium bicarbonate solution is 1: (5-8); the volume ratio of carbon dioxide and air in the mixed gas is 1:5; the drying process using the step-by-step pulse hot pressing process includes a first stage, a second stage and a third stage, wherein the hot pressing temperature in the first stage is 40-60 °C, the hot pressing pressure is 5 MPa, and the hot pressing time is 1-2 min. The hot pressing temperature of the second stage is 65-85 °C, the hot pressing pressure is 2 MPa, and the hot pressing time is 5-10 min, and the pressure is released once every 1 min. The hot pressing temperature of the third stage is 90-110 °C, the hot pressing pressure is normal pressure, and the hot pressing time is 2-5 min. The antibacterial Pickering emulsion stabilizer is obtained by mixing and stirring the antibacterial cellulose nanocrystal solution and the tannic acid solution. The antibacterial extract, the antibacterial aqueous phase material and the antibacterial Pickering emulsion stabilizer are mixed and then ultrasonically emulsified to obtain an O / W Pickering emulsion, wherein the antibacterial aqueous phase material comprises one of a tea tree extract, a rosemary extract and a honeysuckle extract; The O / W Pickering emulsion is sprayed on a pulp molding material for freshness monitoring and then dried to obtain a pulp molding product for freshness monitoring and antibacterial preservation.

2. The method for preparing a multifunctional pulp molded product according to claim 1, wherein: The preparation of Zanthoxylum anthocyanidins and antibacterial extract specifically comprises: Separating the sun-dried Zanthoxylum bungeanum seeds and Zanthoxylum bungeanum peels, and grinding the sun-dried Zanthoxylum bungeanum peels to obtain Zanthoxylum bungeanum peel powder; The Zanthoxylum bungeanum peel powder is mixed with acidic methanol and stirred, and then filtered once to obtain a primary filtrate and a primary filter residue, respectively; the primary filter residue is mixed with acidic methanol under the same conditions and stirred, and then filtered twice to obtain a secondary filtrate and a secondary filter residue, respectively; the primary filtrate and the secondary filtrate are concentrated and evaporated to obtain a concentrated solution; the concentrated solution is freeze-dried to obtain Zanthoxylum bungeanum anthocyanidins; The dried Zanthoxylum bungeanum seeds are added into an organic solvent for reaction to obtain a reaction product, the reaction product is filtered to obtain a product filtrate and a product residue respectively, the product filtrate is allowed to stand and separate into layers to obtain an upper layer of organic matter, and the upper layer of organic matter is subjected to reduced pressure distillation to obtain an antibacterial extract.

3. The method for preparing a multifunctional pulp molded product according to claim 2, wherein: The Zanthoxylum bungeanum peel powder has a particle size of 60-120 mesh; the mass ratio of the Zanthoxylum bungeanum peel powder to the acidic methanol is 1:(20-30); the acidic methanol is obtained by mixing an organic carboxylic acid and methanol at a volume ratio of 5:1, wherein the organic carboxylic acid includes one of tartaric acid, acetic acid, and trifluoroacetic acid; the mixing temperature is 50-60°C and the time is 1-2 hours; the freeze-drying temperature is -50°C and the time is 48 hours; The reaction temperature is 40~50℃, and the time is 2 h; the temperature of the reduced pressure distillation is 50℃, and the time is 1 h.

4. The method for preparing a multifunctional pulp molded product according to claim 1, wherein: The antibacterial cellulose nanocrystal solution is prepared by an antibacterial fiber mixed solution, specifically comprising: The antibacterial fiber mixed liquid and the hydrochloric acid solution are mixed and stirred, and then deionized water is added for centrifugal washing to obtain a suspension. The pH value of the suspension is adjusted to neutral to obtain an antibacterial cellulose nanocrystal solution.

5. The method for preparing a multifunctional pulp molded product according to claim 4, wherein: The mass ratio of the antibacterial fiber mixed solution to the hydrochloric acid solution is 1:(10-20); the mass concentration of the hydrochloric acid solution is 50-70%; the mixing temperature is 40°C, the time is 1-2 hours; the centrifugal washing speed is 3000-4000 rpm, and the time is 10-20 minutes.

6. The method for preparing a multifunctional pulp molded product according to claim 1, wherein: The mass ratio of the antibacterial cellulose nanocrystal solution to the tannic acid solution is 1:(0.1-1); the mixing and stirring treatment time is 1-2 hours; The mass concentration of the antibacterial aqueous phase material was 0.1-0.3%; the mass ratio of the antibacterial extract, antibacterial aqueous phase material, and antibacterial Pickering emulsion stabilizer was 1:(2-4):(0.004-0.006); the ultrasonic emulsification power was 200-400 W, the speed was 12,000 rpm, and the time was 3-5 min.

7. The method for preparing a multifunctional pulp molded product according to claim 1, wherein: The spraying thickness is 5-10 μm; the drying temperature is 40° C., and the drying time is 1-2 h.

8. A multifunctional pulp molded product, characterized in that: The multifunctional pulp molded product is obtained based on the preparation method of any one of claims 1 to 7.

Images