Production method of degradable paper packaging box

Abstract

The invention belongs to the field of packaging box production, and discloses a production method of a degradable paper packaging box, which comprises the following steps: selecting wheat straw pulp and reed pulp as basic raw materials, and further comprises the following steps: S1, pretreating the raw materials; s2, a pulping process step; s3, a forming treatment step; s4, a composite drying step; s5, a secondary strengthening step; s6, a die cutting forming step; according to the production method of the degradable paper packaging box, by improving a raw material formula and a production process, the paper packaging box which has the excellent characteristics of high strength, high toughness and the like while the degradability is guaranteed is prepared, and the requirements of the market for environment-friendly and durable packaging products are met.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging box production, and in particular to a method for producing a degradable paper packaging box. Background Art

[0002] With growing global environmental awareness, paper packaging, due to its renewable and recyclable properties, is becoming increasingly widely used in the packaging field and is gradually becoming an important alternative to plastic packaging. However, biodegradable paper packaging currently on the market still faces many challenges in practical application. From a raw material perspective, most traditional paper packaging boxes use ordinary wood pulp as their primary raw material, which consumes a lot of resources and requires a large amount of chemical additives during production to improve performance. This not only increases the risk of environmental pollution but also slows the degradation of the product in the natural environment. Furthermore, some paper packaging boxes made from recycled fiber have inconsistent fiber quality, resulting in finished products that lack the strength required for packaging and are prone to damage during transportation and storage. Existing technologies also have significant deficiencies in production processes. For example, conventional pulping processes often use low-consistency refining, which over-cuts fibers, shortening them and reducing paper strength. During the forming process, conventional Fourdrinier wire forming machines struggle to achieve uniform fiber distribution, resulting in poor wet paper uniformity and impacting the overall quality of the packaging. Using only hot air for drying can lead to uneven drying and paper deformation. Furthermore, most production methods lack secondary treatments to enhance paper performance, resulting in poor weather resistance and antibacterial properties. The rapid development of e-commerce and logistics has placed higher demands on the strength, toughness, water resistance, and environmental friendliness of paper packaging. Traditional paper packaging production technology is no longer able to meet market demand. To address these challenges, a method for producing paper packaging that combines high strength and biodegradability has been proposed, aiming to promote the green and sustainable development of the packaging industry. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for producing a degradable paper packaging box. By improving the raw material formula and production process, a paper packaging box is prepared that has excellent properties such as high strength and high toughness while ensuring degradability, so as to meet the market demand for environmentally friendly and durable packaging products.

[0004] In order to achieve the above object, the present invention provides the following technical solutions: The technical solution provided by the present invention is: a method for producing a degradable paper packaging box, characterized in that it includes the following steps: S1: Raw material pretreatment step: Wheat straw pulp and reed pulp are mixed in a mass ratio of 2:3 to obtain a basic mixed pulp. Wheat straw pulp and reed pulp are both renewable and degradable plant fiber raw materials with a wide range of sources and relatively low costs. Add 3% of carboxymethyl cellulose nanofibers and 1.5% of calcium lignin sulfonate by mass to the basic mixed pulp, and stir at a stirring speed of 350r / min for 40 minutes at 60°C to fully mix the raw materials and exert a synergistic enhancement effect. The average diameter of the carboxymethyl cellulose nanofibers is 10-50nm and the length is 0.5-5μm. Its nanoscale size can effectively fill the gaps between fibers and enhance the interaction between fibers; calcium lignin sulfonate has a dispersing and bonding effect, which helps to improve the mixing uniformity and molding properties of the raw materials. Before adding carboxymethyl cellulose nanofibers and calcium lignin sulfonate, wheat straw pulp and reed pulp can be placed in water with a mass fraction of 3% sodium hydroxide solution and treated at 50°C for 1.5 hours to perform delignification and swelling treatment to further improve the reactivity and processability of the fibers.

[0005] S2: Pulping process steps: put the mixed pulp after raw material pretreatment into the disc mill, adopt medium-consistency refining method, and control the refining concentration at 5%. Compared with low-consistency and high-consistency refining, medium-consistency refining can better retain fiber length and strength and improve pulp quality. During the refining process, nano-montmorillonite accounting for 2% of the mass of the mixed pulp is added, and the nano-montmorillonite lamellar structure is used to intersperse in the fiber gaps to enhance the stability of the internal structure of the pulp; at the same time, guar gum accounting for 0.8% of the mass of the mixed pulp is added to improve the papermaking performance of the pulp and make the pulp easier to operate during the forming process. The grinding disc gap of the disc mill is set to 0.1-0.3mm, and the grinding disc speed is 1500-2000r / min. Under these parameters, moderate cutting and fibrillation of the fibers can be achieved, and the pulp performance can be optimized. The refining time is 18 minutes to prepare enhanced pulp.

[0006] S3: Forming treatment step: The reinforced pulp is formed into a wet paper web with the help of an inclined wire former. The inclined wire former can form a more orderly arrangement of the fibers during the forming process, thereby improving the uniformity and strength of the wet paper web. During the forming process, a low-temperature plasma with a power of 300W is introduced to treat the surface of the wet paper web for 3 minutes to improve the bonding force between the fibers. The low-temperature plasma treatment uses a radio frequency power supply with an operating frequency of 13.56MHz, argon as the processing gas, a gas flow rate of 50sccm, and the pressure of the processing chamber is maintained at 10Pa. The action of the low-temperature plasma can activate the fiber surface, increase the surface polar groups, and promote hydrogen bonding and physical entanglement between the fibers.

[0007] S4: Combined Drying Step: The wet paper web is first transferred to a microwave drying zone with an 800W power output for 8 minutes to quickly remove most of the moisture. Microwave drying offers the advantages of rapid heating and uniform drying, rapidly vaporizing the moisture in the wet paper web in a short period of time. The paper web is then transferred to a vacuum drying zone at a pressure of -0.08MPa and a temperature of 55°C for 12 minutes to ensure uniform drying, resulting in a dry paper blank. Vacuum drying further removes residual moisture and prevents high temperatures from damaging the paper's properties. Between the microwave and vacuum drying zones, an infrared heating and smoothing process is implemented. Using infrared light with a wavelength of 2-4μm, the paper web is heated at 100°C for 5 minutes to eliminate wrinkles created during the drying process and smoothen the surface of the paper blank. The microwave drying zone utilizes a microwave frequency of 2450MHz, and a rotating tray is installed within the drying chamber to ensure uniform drying.

[0008] S5: Secondary strengthening step: The dried paper blank is immersed in water containing 8% mass concentration of konjac glucomannan solution for 12 minutes. Konjac glucomannan has good film-forming and adhesive properties, and can form a protective film on the surface and inside of the paper blank, thereby enhancing the strength and flexibility of the paper. After removal, a layer of titanium dioxide nanofilm is deposited on the surface of the paper blank using chemical vapor deposition technology to improve the strength and weather resistance of the paper blank. The chemical vapor deposition technology uses titanium isopropoxide as a precursor, nitrogen as a carrier gas, a carrier gas flow rate of 100 sccm, a deposition temperature of 300°C, and a deposition time of 30 minutes. The titanium dioxide nanofilm not only improves the mechanical properties of the paper, but also has certain antibacterial and UV resistance properties.

[0009] S6: Die-cutting and forming step: According to the design specifications of the packaging box, use a CNC die-cutting machine to die-cut and fold the secondary reinforced paper blank to make a biodegradable paper packaging box. The CNC die-cutting machine can accurately control the size and shape to ensure the accuracy and quality of the packaging box. After the die-cutting and forming step is completed, the packaging box is subjected to a UV-ozone combined treatment. Under the UV intensity of 20W / m 2 、Ozone concentration 50mg / m 3 The packaging box is treated in an environment for 10 minutes to further enhance its antibacterial properties.

[0010] The beneficial effects of this technical solution are: (1) The present invention innovatively uses wheat straw pulp and reed pulp as basic raw materials. Both are agricultural wastes with a wide range of sources and low cost, achieving efficient resource utilization while significantly reducing dependence on forest resources. Combined with additives such as carboxymethyl cellulose nanofibers and calcium lignin sulfonate, the paper packaging box not only fully exerts its synergistic enhancement effect and significantly improves the mechanical properties of the paper packaging box, such as tensile strength and burst resistance, but also has good biodegradability. Compared with traditional paper packaging boxes, the degradation time in the natural environment is shortened by 20%-30%, truly achieving an organic combination of environmental protection and performance. (2) Each production process step is closely coordinated and innovative. The addition of nano-montmorillonite and guar gum to the medium-consistency pulping not only effectively retains the fiber length, but also enhances the internal structural stability of the pulp and improves the papermaking performance. Low-temperature plasma treatment can activate the fiber surface, increasing the bonding force between fibers by 30%-50%, thereby enhancing the overall strength of the paper. The composite drying and infrared leveling process, through microwave rapid dehydration, vacuum uniform drying and infrared leveling treatment, not only improves the drying efficiency, but also ensures the smoothness of the paper surface, avoiding quality defects caused by drying problems. In the secondary strengthening step, the konjac glucomannan solution impregnation and titanium dioxide nanofilm deposition give the packaging box excellent strength, weather resistance and antibacterial properties. The antibacterial rate can reach more than 90% after testing. (3) The paper packaging box produced by the method of the present invention has excellent mechanical properties, environmental performance and functionality. Compared with traditional methods, the tensile strength is increased by 30%-50%, and the burst resistance is increased by 20%-35%. It can withstand greater pressure and weight, effectively ensuring the safety of packaged items. Its good biodegradability allows it to decompose quickly after disposal, reducing environmental pollution. In addition, the packaging box also has excellent antibacterial, water-resistant, and UV-resistant properties, which broadens the product's application scenarios and can be widely used in the packaging of various products such as food, medicine, and electronic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a data comparison table of various embodiments of the production method of a degradable paper packaging box proposed in the present invention; Figure 2 The following is a parameter comparison table of various embodiments of the production method of a degradable paper packaging box proposed in the present invention. DETAILED DESCRIPTION

[0012] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments 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 are within the scope of protection of the present invention.

[0013] The specific implementation process is as follows: Example 1: See also Figure 1-2 The present invention provides a technical solution: a method for producing a degradable paper packaging box, comprising the following steps: S1: Raw material pretreatment: Accurately weigh 40 kg of wheat straw pulp and 60 kg of reed pulp, place them in a stirring container and mix them to obtain a basic mixed pulp; add 3% by weight of carboxymethyl cellulose nanofibers (average diameter 10 nm, length 0.5 μm) and 1.5% of calcium lignin sulfonate to the basic mixed pulp, heat the stirring container to 60°C, and stir continuously at a stirring speed of 350 r / min for 40 minutes; before this, place the wheat straw pulp and reed pulp in water containing 3% by weight of sodium hydroxide solution and treat at 50°C for 1.5 hours to perform delignification and swelling treatment; S2: Pulping process: The pretreated mixed pulp is put into a disc refiner and refined in a medium-consistency manner, with the pulp concentration controlled at 5%. During the refining process, 2% of the mass of the mixed pulp is added with nano-montmorillonite and 0.8% of guar gum. The disc gap is set to 0.1 mm, the disc speed is set to 1500 r / min, and the pulp is refined for 18 minutes to obtain enhanced paper pulp. S3: Forming treatment: The reinforced pulp is formed into a wet paper web using an inclined wire former. During the forming process, a low-temperature plasma with a power of 300 W is introduced, using a radio frequency power supply (operating frequency 13.56 MHz) and argon as the treatment gas (gas flow rate 50 sccm) at a treatment chamber pressure of 10 Pa for 3 minutes to treat the wet paper web surface. S4: Combined drying: The wet paper web is first conveyed to a microwave drying zone with a power of 800W, a frequency of 2450MHz, and a rotating tray for drying for 8 minutes. It is then transferred to a vacuum drying zone with a pressure of -0.08MPa and a temperature of 55°C for drying for 12 minutes. Between the microwave drying zone and the vacuum drying zone, the paper web is heated at 100°C for 5 minutes using infrared light with a wavelength of 2μm. S5: Secondary strengthening: The dried paper blank was immersed in water containing 8% konjac glucomannan solution for 12 minutes. After removal, chemical vapor deposition (CVD) was performed at 300°C for 30 minutes using titanium isopropoxide as a precursor and nitrogen as a carrier gas (flow rate of 100 sccm) to form a titanium dioxide nanofilm with a thickness of about 500 nm on the surface of the paper blank. S6: Die-cutting: Use CNC die-cutting machine to die-cut and fold the paper blank according to the predetermined specifications to make paper packaging boxes. Finally, place the paper blank under ultraviolet light with an intensity of 20W / m 2 、Ozone concentration 50mg / m 3 Process for 10 minutes in an environment; In Example 1, in terms of raw material selection, wheat straw pulp and reed pulp are used to replace traditional wood pulp, which not only realizes the high-value utilization of agricultural waste and reduces production costs, but also reduces forest resource consumption and practices the concept of green environmental protection; the added carboxymethyl cellulose nanofiber and calcium lignin sulfonate give full play to the synergistic effect, so that the tensile strength of the packaging box reaches 82N / 15mm and the bursting strength is 2.1kPa, which is significantly improved compared with traditional paper packaging boxes, effectively solving the problem of insufficient strength in the background technology; in terms of process, innovative processes such as medium-consistency refining, low-temperature plasma treatment, composite drying and secondary strengthening are closely coordinated to ensure the integrity of the fiber structure, enhance the bonding force between fibers, improve the drying quality, and give the packaging box good weather resistance and antibacterial properties, with an antibacterial rate of 92.5%. It begins to degrade significantly in 2.8 months in the natural environment, fully overcoming the defects of the existing technology in process and performance; from raw materials to process, this embodiment shows that the produced packaging box far exceeds traditional products in mechanical properties, environmental performance and functionality, and is easy to industrialize, with both economic and social benefits.

[0014] Example 2: See also Figure 1-2 The present invention provides a technical solution: a method for producing a degradable paper packaging box, comprising the following steps: S1: Raw material pretreatment: As in Example 1, 30 kg of wheat straw pulp and 45 kg of reed pulp were mixed to obtain a base mixed pulp; 3% of the mass of the mixed pulp was carboxymethyl cellulose nanofibers (average diameter 30 nm, length 2 μm) and 1.5% of calcium lignin sulfonate were added, and the mixture was stirred at 60°C and 350 rpm for 40 minutes; similarly, the wheat straw pulp and reed pulp were first subjected to alkali treatment; S2: Pulping process: Same as Example 1, the mixed pulp was put into the disc refiner, the refining concentration was kept at 5%, nano-montmorillonite and guar gum were added, the disc gap was adjusted to 0.2 mm, the disc speed was 1700 r / min, and the pulp was refined for 18 minutes; S3: Forming treatment: The same low-temperature plasma treatment parameters as in Example 1 are used to perform wet paper web forming treatment; S4: Composite drying: Same as in Example 1, microwave drying and vacuum drying parameters are the same as in Example 1, except that the infrared wavelength is changed to 3 μm; S5: Secondary strengthening: Same as in Example 1, konjac glucomannan solution impregnation and chemical vapor deposition operations are the same as in Example 1; S6: Die-cutting and forming: Same as in Example 1, die-cutting, folding and post-processing are completed according to predetermined specifications; Example 2 further optimizes product performance by adjusting the size of carboxymethyl cellulose nanofibers in the raw materials and some process parameters; under the synergistic effect of the raw materials, the tensile strength is increased to 88N / 15mm, and the bursting resistance reaches 2.3kPa, which is a greater improvement than that of traditional technologies, fully demonstrating the superiority and controllability of the raw material formula of the present invention; the synergy of medium-consistency pulping and other innovative processes enables the fibers to be reasonably processed, which not only ensures the fiber length but also enhances the internal structure. At the same time, processes such as low-temperature plasma treatment effectively improve the fiber bonding force and further enhance the strength of the paper; the packaging box produced in this example begins to degrade significantly after 2.7 months, and the antibacterial rate reaches 93.5%. It performs well in terms of environmental protection and functionality, not only solving the problem of the difficulty in balancing the strength and degradability of traditional paper packaging boxes, but also achieving transcendence in performance, reflecting that this technology still has significant progress and creativity under different parameter combinations, and provides strong support for the flexible adjustment of process parameters according to demand in actual production, and has important application value and market competitiveness.

[0015] Example 3: See also Figure 1-2 The present invention provides a technical solution: a method for producing a degradable paper packaging box, comprising the following steps: S1: Raw material pretreatment: As in Example 1, 50 kg of wheat straw pulp and 75 kg of reed pulp were mixed, 4.5 kg of carboxymethyl cellulose nanofibers (average diameter 50 nm, length 5 μm) and 2.25 kg of calcium lignin sulfonate were added, and the mixture was stirred and alkali treated according to conventional conditions; S2: Pulping process: same as Example 1, grinding concentration 5%, adding nano-montmorillonite and guar gum, setting the grinding disc gap to 0.3 mm, grinding disc speed to 2000 r / min, and grinding for 18 minutes; S3: Molding treatment: Same as in Example 1, using the low-temperature plasma treatment parameters of Example 1; S4: Composite drying: Same as in Example 1, except that the parameters of each drying zone remain unchanged and the infrared wavelength is set to 4 μm; S5: Secondary strengthening: Same as Example 1, with the same impregnation and chemical vapor deposition operations as Example 1; S6: Die-cutting and forming: same as in Example 1, completing the die-cutting, folding and post-processing steps; After the raw materials and process parameters of Example 3 were adjusted, although some mechanical properties were slightly lower than those of Example 2, the tensile strength of 76N / 15mm and the bursting strength of 1.8kPa were still much higher than those of traditional paper packaging boxes, and it began to degrade significantly after 3 months in the natural environment, with an antibacterial rate of 91%, and the overall performance was still excellent. In this example, the degradable properties of the raw materials and the application of innovative processes fundamentally improved the performance defects of traditional paper packaging boxes. For example, the addition of nano-montmorillonite and guar gum can maintain high strength performance even when the grinding disc parameters are adjusted to cause slightly excessive fiber cutting, which reflects the stability and adaptability of the process of the present invention. At the same time, this example further verifies the feasibility of this technology under different parameter conditions, and the packaging boxes produced by it have obvious superior effects in terms of environmental protection and functionality compared with the existing technology.

[0016] Example 4: See also Figure 1-2 The present invention provides a technical solution: a method for producing a degradable paper packaging box, comprising the following steps: S1: Raw material pretreatment: As in Example 1, prepare 38 kg of wheat straw pulp and 57 kg of reed pulp, add carboxymethyl cellulose nanofibers and calcium lignin sulfonate, and stir, mix and treat with alkali according to standard procedures; S2: Pulping process: same as Example 1, with a refining concentration of 5%, addition of nano-montmorillonite and guar gum, a grinding disc gap of 0.15 mm, a grinding disc speed of 1600 r / min, and a refining time extended to 22 minutes; S3: Molding treatment: same as in Example 1, low-temperature plasma treatment parameters are the same as in Example 1; S4: composite drying: same as in Example 1, with the drying process parameters unchanged; S5: Secondary strengthening: Same as in Example 1, the impregnation and chemical vapor deposition operations are the same as in Example 1; S6: Die cutting and molding: same as in Example 1, completing all production processes; Example 4 further optimizes the fiber fibrillation and nanomaterial dispersion effects by extending the refining time, so that the tensile strength of the packaging box reaches 85N / 15mm, the bursting strength is 2.2kPa, and the performance is excellent; in the entire production process, the raw material formula and process system of the present invention work together, from raw material pretreatment to remove impurities and enhance fiber activity, to pulping process to improve pulp performance, and then to molding, drying and secondary reinforcement to improve paper comprehensive performance. Each link has been innovatively improved to address the deficiencies in the background technology; the packaging box produced in this embodiment began to degrade significantly after 2.8 months, with an antibacterial rate of 92.8%. While achieving high strength, it ensures good degradability and antibacterial properties. Compared with traditional paper packaging boxes, it has achieved a qualitative leap in performance and environmental protection, fully reflecting the significant progress and creativity of this technology, and demonstrating the huge potential of the production method of the present invention in optimizing product performance. It is of great significance to promote technological upgrading in the paper packaging box industry.

[0017] Comparative Example 1 (traditional process control) S1: Raw material pretreatment: Ordinary wood pulp is used as raw material, without adding special materials such as carboxymethyl cellulose nanofiber and calcium lignin sulfonate, and only conventional screening and purification treatment is performed; S2: Pulping process: low-consistency refining was used, the refining concentration was 3%, no nano-montmorillonite and guar gum were added, and the refining time was 15 minutes; S3: Forming treatment: forming the wet paper web by a common Fourdrinier forming machine without the low-temperature plasma treatment step; S4: Drying step: using single hot air drying, temperature 70 ° C, drying time 25 minutes; S5: Post-treatment: No secondary strengthening treatment, only simple die-cutting and molding, no UV-ozone combined treatment; Comparative Example 1 adopts traditional technology to produce paper packaging boxes, and does not adopt the scheme of the present invention from raw materials to processes. The packaging boxes produced by it have a tensile strength of only 55N / 15mm and a bursting strength of 1.2kPa. It takes about 4 months to degrade in a natural environment and has no antibacterial effect. This is in sharp contrast to the embodiments of the present invention, which fully exposes the limitations of traditional technology in raw material utilization and process technology, and is unable to meet the requirements of the modern packaging industry for high strength, environmental protection and functionality, further highlighting the significant progress and creativity of the technical scheme of the present invention in improving the performance of paper packaging boxes and promoting the green development of the industry.

[0018] Comparative Example 2 (Partial process missing control) S1: Raw material pretreatment: Prepare 40 kg of wheat straw pulp and 60 kg of reed pulp, mix the two, add 3% by weight of carboxymethyl cellulose nanofibers and 1.5% by weight of calcium lignin sulfonate, and then stir and mix. Place the wheat straw pulp and reed pulp in water containing 3% by weight of sodium hydroxide solution and treat at 50°C for 1.5 hours to complete the alkaline treatment; S2: Pulping process: Same as in Example 1, the mixed pulp was put into a disc refiner, and the medium-consistency refining method was adopted. The refining concentration was controlled at 5%, and nano-montmorillonite and guar gum were added, and the pulp was refined for 18 minutes; S3: Forming treatment: The pulp is formed into a wet paper web by means of an inclined wire former, but no low-temperature plasma treatment is performed; S4: Composite drying: The wet paper web is first conveyed to the microwave drying zone and then transferred to the vacuum drying zone, but without the infrared heating and leveling process; S5: Secondary strengthening: The dried paper blank was immersed in water containing 8% konjac glucomannan solution for 12 minutes without chemical vapor deposition treatment; S6: Die-cutting and forming: die-cutting and folding are completed without UV-ozone combined treatment; Although Comparative Example 2 adopts some of the raw materials and processes of the present invention, due to the lack of key processes such as low-temperature plasma treatment, infrared heating and leveling process, chemical vapor deposition treatment and ultraviolet-ozone combined treatment, the produced packaging box has a tensile strength of 68N / 15mm, a bursting resistance of 1.5kPa, a degradation time of 3.2 months, and an antibacterial rate of 85%, and its performance is significantly lower than that of the embodiment of the present invention; this strongly proves the importance of the mutual coordination and synergistic enhancement of the various process steps of the present invention. Only by fully adopting the technical scheme of the present invention can the maximum value of the raw materials and processes be realized, and a paper packaging box with high strength, degradability and excellent functionality can be produced.

[0019] See also Figure 1-2 : Under the general trend of the packaging industry's transformation towards green and environmental protection, this technology addresses the pain point of traditional paper packaging boxes, which are difficult to strike a balance between strength and degradability, and provides a new direction for the development of the industry in terms of raw material formulation; traditional paper packaging boxes mostly rely on ordinary wood pulp, which consumes a lot of resources and requires the addition of non-degradable chemical additives, while this technology uses agricultural waste such as wheat straw pulp and reed pulp as basic raw materials, which not only reduces dependence on forest resources, but also realizes the recycling of resources and significantly reduces production costs; at the same time, it innovatively adds ingredients such as carboxymethyl cellulose nanofibers and calcium lignin sulfonate. These nano-scale materials have unique The unique size and performance can effectively fill the fiber gaps, enhance the interaction between fibers, and produce a synergistic effect with the basic raw materials. According to the data in the examples, in Examples 1-4, the tensile strength of the packaging boxes produced by adopting this raw material formula reaches more than 70N / 15mm, far exceeding the 55N / 15mm of the traditional process comparative example 1, and all raw materials are degradable materials. The degradation time in the natural environment is shortened by 20%-30% compared with traditional packaging boxes, which successfully solves the problem of the inability to balance environmental protection and performance in traditional technologies. This innovation in raw material formula is groundbreaking and has opened up a new path for the production of paper packaging boxes.

[0020] In terms of production technology, each process step of this technical solution has been carefully designed and coordinated with each other to form an organic whole, which is the key difference from the existing technology; the pulping process adopts a medium-consistency refining method and adds nano-montmorillonite and guar gum. Compared with traditional low-consistency refining, it can better retain fiber length and strength. At the same time, nano-montmorillonite enhances the internal structural stability of the pulp, and guar gum improves the papermaking performance. From the comparison of Example 2 and Example 4, it can be seen that the product strength of Example 2 with the addition of guar gum is significantly higher; low-temperature plasma technology is introduced in the molding process to activate the fiber surface and enhance the bonding force between fibers. For example, after this treatment, the tensile strength of the packaging box in Example 1 reaches 82N / 15mm; the composite drying step combines microwave drying, vacuum drying and infrared leveling processes, which not only improves the drying efficiency but also ensures the quality of the paper blank; the secondary strengthening step uses konjac glucomannan solution impregnation and chemical vapor deposition technology to give the packaging box excellent strength, weather resistance and antibacterial properties; the synergistic effect of these processes makes the packaging box produced by this technology surpass traditional products in all aspects of performance.

[0021] From the perspective of product performance, the paper packaging box produced by this technical solution has achieved a qualitative leap, far exceeding the existing technology in many key indicators, fully demonstrating its creativity and practicality; in terms of mechanical properties, the tensile strength and burst resistance are greatly improved. The tensile strength of Example 2 is as high as 88N / 15mm, and the burst resistance reaches 2.3kPa, which are improved by more than 30% and 50% respectively compared with the traditional process comparative example 1. It can withstand greater pressure and weight, effectively ensuring the safety of packaged items during transportation and storage; in terms of environmental performance, due to the degradable nature of the raw materials and the absence of harmful chemical additives, the degradation time is significantly shortened The packaging boxes of all embodiments can begin to degrade significantly in the natural environment in about 3 months, which meets the environmental protection requirements; in terms of functionality, through secondary strengthening and post-processing processes, the packaging boxes have excellent antibacterial, water-resistant, UV-resistant and other properties, and the antibacterial rate generally reaches more than 90%. They can be widely used in the packaging of various products such as food, medicine, and electronic products, expanding the application field of paper packaging boxes; compared with the existing technology, the packaging boxes produced by this technology have a comprehensive improvement in performance, which not only meets the market demand for high-quality packaging products, but also promotes the technological upgrading of the paper packaging box industry, and has important economic and social benefits.

[0022] Test methods for experimental data: Tensile strength test: The test is conducted in accordance with GB / T12914-2018 "Paper and paperboard - Determination of tensile strength". Samples with a width of 15mm and a length of 250mm are cut from the prepared paper packaging boxes. Ten samples are selected for each test and mounted on the fixtures of an electronic universal material testing machine. The initial fixture spacing is set to 180mm, and the tensile speed is set to 100mm / min. The testing machine is started, and the maximum tensile force when the sample breaks is recorded. The average value of the test results of the 10 samples is taken as the tensile strength of the packaging box. This test method is based on the principle of material tensile fracture. By measuring the maximum tensile force that the sample can withstand during the stretching process and combining the sample width, the tensile force per unit width is calculated to evaluate the tensile properties of the paper packaging box.

[0023] Burst resistance test: In accordance with GB / T454-2002 "Determination of burst resistance of paper", a Müllen burst tester is used. Circular specimens with a diameter of 70mm are cut from different parts of the packaging box. Ten specimens are prepared for each test. The specimens are clamped between the chucks of the burst tester and uniformly pressurized at a rate of 170kPa / min±15kPa / min until the specimens rupture. The pressure at rupture is recorded. The average of the test results of the ten specimens is also taken as the burst resistance of the packaging box. This test simulates the uniform pressure of the packaging box in actual use. By measuring the pressure at the time of specimen rupture, the packaging box's ability to resist local pressure is reflected.

[0024] Degradation time test: The compost degradation test method is adopted, referring to the ISO14855-1:2012 "Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions". The packaging box is cut into small pieces of approximately 50mm×50mm in size. A certain mass (about 100g) of sample is taken and evenly mixed into a composting medium that meets the standard requirements. The humidity of the composting medium is controlled at 50%-60%, and the temperature is maintained at 58℃±2℃. The compost is turned regularly to ensure oxygen supply. The sample is taken out at regular intervals (such as weekly) and its appearance is observed for changes. When the mass loss of the sample reaches more than 50% and the appearance shows obvious signs of fragmentation and decomposition, the time at this time is recorded as the degradation time. This method simulates the natural composting environment and can truly reflect the degradation of the packaging box under natural conditions.

[0025] The above is only an embodiment of the present invention, and common knowledge such as the specific technical solutions or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A method for producing a degradable paper packaging box, characterized in that: The steps include: S1: Raw material pretreatment step: Wheat straw pulp and reed pulp were mixed in a mass ratio of 2:3 to obtain a basic mixed pulp; 3% by mass of carboxymethyl cellulose nanofibers and 1.5% by mass of calcium lignin sulfonate were added to the basic mixed pulp, and stirred at a stirring speed of 350 r / min at 60°C for 40 minutes; The carboxymethyl cellulose nanofibers have an average diameter of 10-50 nm and a length of 0.5-5 μm. S2: Pulping process: The pre-treated mixed pulp is fed into a disc refiner and refined at a medium-consistency refining method, with the refining concentration controlled at 5%. During the refining process, nano-montmorillonite, accounting for 2% of the mixed pulp mass, is added. The nano-montmorillonite flake structure is interspersed in the fiber gaps. The refining time is 18 minutes to produce reinforced paper pulp. The grinding disc gap of the disc grinder is set to 0.1-0.3 mm, and the grinding disc speed is 1500-2000 r / min; S3: Forming treatment step: The reinforced pulp is formed into a wet paper web by means of an inclined wire former; during the forming process, a low-temperature plasma with a power of 300 W is introduced to treat the surface of the wet paper web for 3 minutes; The low-temperature plasma treatment uses a radio frequency power supply with an operating frequency of 13.56 MHz, argon as the processing gas, a gas flow rate of 50 sccm, and the processing chamber pressure is maintained at 10 Pa; S4: Composite drying step: The wet paper web is first transferred to a microwave drying zone with a power of 800W for 8 minutes to quickly remove most of the moisture; then transferred to a vacuum drying zone with a pressure of -0.08MPa and a temperature of 55°C for 12 minutes to ensure drying uniformity, thereby obtaining a dry paper blank; The microwave drying zone uses a microwave frequency of 2450 MHz, and a rotating tray is set in the drying chamber to ensure uniform drying; S5: Secondary strengthening step: The dried paper blank is immersed in a konjac glucomannan solution with a mass concentration of 8% for 12 minutes. After removal, a titanium dioxide nanofilm is deposited on the surface of the paper blank using chemical vapor deposition technology; The chemical vapor deposition technology uses titanium isopropoxide as a precursor, nitrogen as a carrier gas, a carrier gas flow rate of 100 sccm, a deposition temperature of 300°C, and a deposition time of 30 minutes; S6: Die-cutting and forming step: According to the design specifications and dimensions of the packaging box, use a CNC die-cutting machine to die-cut and fold the secondary reinforced paper blank to make a degradable paper packaging box.

2. The method for producing a degradable paper packaging box according to claim 1, characterized in that: In the S1 raw material pretreatment step, before adding carboxymethyl cellulose nanofibers and calcium lignin sulfonate, the wheat straw pulp and reed pulp are placed in water with a mass fraction of 3% sodium hydroxide solution and treated at 50° C. for 1.5 hours to perform delignification and swelling treatment.

3. The method for producing a degradable paper packaging box according to claim 1, characterized in that: In the S2 pulping process step, when the nano-montmorillonite is added, guar gum accounting for 0.8% of the mass of the mixed pulp is added at the same time.

4. The method for producing a degradable paper packaging box according to claim 1, characterized in that: In the S4 composite drying step, an infrared heating and leveling process is set between the microwave drying zone and the vacuum drying zone, using infrared rays with a wavelength of 2-4 μm to heat the paper web at 100° C. for 5 minutes.

5. The method for producing a degradable paper packaging box according to claim 1, characterized in that: After the S5 die-cutting step is completed, the packaging box is subjected to a UV-ozone combined treatment. 2 、Ozone concentration 50mg / m 3 Process for 10 minutes under the environment.

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