A degradable paper-plastic material and its preparation method and application

Abstract

The present invention provides a degradable paper-plastic material and a preparation method and application thereof, belonging to the technical field of environmentally friendly materials. The degradable paper-plastic material of the present invention comprises the following raw materials in weight percentage: 90-95.5% of plant fiber pulp board, 1.5-3% of sizing agent, 0-5% of oil-proof agent, 1-2% of dry strength agent, and 1-2% of wet strength agent. The above-mentioned raw materials are sequentially prepared through pulping, slurry mixing, molding, hot pressing and shaping, shaping and trimming, and assembly processes to prepare the degradable paper-plastic material. The preparation method of the present invention is simple, low in cost, the surface of the obtained material is smooth and beautiful, the material has high strength, good waterproof and moisture-proof properties, and is a completely degradable material. At the same time, the material has good plasticity and can be used to manufacture various packaging boxes and electronic cigarette pipes.

Description

Technical Field

[0001] The invention belongs to the technical field of environmentally friendly materials, and specifically relates to a degradable paper-plastic material and a preparation method and application thereof. Background Art

[0002] Disposable plastic packaging products are widely used in the packaging industry. They are usually discarded after one use, which causes great waste of resources. At the same time, plastics are difficult to degrade naturally. They need to be buried underground for more than 100 years to degrade naturally. The huge amount of discarded plastic packaging products poses a great threat to the ecological environment, and banning the use of non-degradable disposable plastic packaging products has become a global consensus. Developing green and environmentally friendly packaging products is the only way to build a resource-saving and environmentally friendly society, adhere to sustainable development, and fully achieve carbon neutrality.

[0003] Among green and environmentally friendly packaging products, pulp molding products are packaging products that use plant fibers as raw materials. Because their raw materials come from nature, waste can be recycled and reused after use, and they can be naturally degraded, so they have broad development prospects. The natural degradation time of pulp molding products in the open air is about 120 days, and the natural landfill can be completed within 60 days, which greatly reduces the pollution to the environment. However, most pulp molding products have the disadvantages of complex manufacturing process and high manufacturing cost. At the same time, there are also problems such as uneven surface of the material, rough appearance, poor material plasticity, low strength, and poor waterproof and moisture resistance. These problems greatly limit its application in packaging materials. Therefore, it is urgent to develop a waterproof, moisture-proof, high-strength, and easily degradable pulp molding product to replace disposable plastic packaging products and meet market requirements. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a degradable paper-plastic material and a preparation method and application thereof.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: the present invention provides a degradable paper-plastic material, comprising the following preparation raw materials in weight percentage: 90-95.5% of plant fiber pulp board, 1.5-3% of sizing agent, 0-5% of oil-proof agent, 1-2% of dry strength agent, and 1-2% of wet strength agent; the plant fiber pulp board comprises wood pulp board and / or sugarcane pulp board.

[0006] The raw materials for preparing the degradable paper-plastic material of the present invention are mainly plant fiber pulp boards, which account for 87-93% of the raw material composition, specifically including wood pulp boards and / or sugarcane pulp boards. Because the main material is plant fiber pulp boards, the material of the present invention is a completely degradable material, and can be basically degraded after being placed under natural conditions for 120 days. In addition, the degradable paper-plastic material prepared within the above-mentioned ratio range is compounded by sizing agent, oil-proof agent, dry strength agent and wet strength agent components, which significantly improves the strength, waterproof, oil-release and moisture-proof properties of the paper-plastic material.

[0007] As a preferred embodiment of the present invention, the degradable paper-plastic material comprises the following raw materials in weight percentage: 90-95.5% plant fiber pulp, 1.5-2% sizing agent, 0-5% oil-proofing agent, 1-1.5% dry strength agent, and 1.5-2% wet strength agent.

[0008] As a preferred embodiment of the present invention, the mass ratio of the wood pulp board to the sugarcane pulp board is (5-7): (3-5).

[0009] The inventors have found through research that wood fiber is generally 2.5-4 mm long and 35-55 μm wide, and sugarcane fiber is generally 1.0-2.0 mm long and 6-16 μm wide. By adjusting the mass ratio of wood pulp to sugarcane pulp, the length range of plant fiber in the pulverized pulp can be adjusted, which will ultimately affect the strength and surface smoothness of the product. When the mass ratio of wood pulp to sugarcane pulp is (5-7): (3-5), the length of plant fiber in the pulverized pulp is 0.45 μm-1.2 mm, the product surface is smooth and flat, and has good pressure resistance.

[0010] As a preferred embodiment of the present invention, the oil repellent comprises at least one of perfluorooctanoate, perfluorooctane sulfonyl compound, alkylphenol polyoxyethylene ether and perfluorohexane sulfonyl compound.

[0011] The inventors have found through research that the straight-chain carbon fluorine organic compound of the oil-proof agent can combine with the fiber to form a chemical bond, thereby improving the physical strength and oil-proof performance of the finished product.

[0012] As a preferred embodiment of the present invention, the sizing agent includes at least one of alkyl ketene dimer, alkenyl succinic anhydride, rosin sizing agent and paraffin sizing agent.

[0013] The inventors have found through research that adding a water-resistant colloidal substance into the slurry can prevent water from penetrating and spreading into paper-plastic products, thereby achieving good waterproof and moisture-proof properties.

[0014] As a preferred embodiment of the present invention, the dry strength agent includes at least one of cationic starch, anionic starch, and ionic polyacrylamide.

[0015] The inventors have found through research that adding a dry strength agent to the slurry can improve the stiffness and strength of the product.

[0016] As a preferred embodiment of the present invention, the wet strength agent includes at least one of polyamide epichlorohydrin resin, melamine formaldehyde resin and urea formaldehyde resin.

[0017] The inventor has found through research that wet strength agent can increase the water resistance of paper plastic products, that is, increase the wet strength of the products. Its mechanism of action is: when the paper plastic products are wetted, the cellulose inside absorbs water rapidly, and the hydrogen bonding between the fibers is significantly weakened, resulting in a decrease in the temperature strength of the products. For paper pulp with polyamide epichlorohydrin thermosetting resin, the positive charge of the wet strength resin attracts the negatively charged paper fibers, and at the same time, the hydroxyl groups contained in the wet strength agent form hydrogen bonds with the fiber hydroxyl groups. These two effects cause a large amount of wet strength resin to be adsorbed on the fiber surface. Therefore, when the paper plastic products are dried, affected by the surface temperature of the hot pressing mold, the hydrogen bonds between the molecules lose water, and the wet strength resin added to the paper plastic products undergoes polycondensation at the same time. At this time, the resin is converted into a water-insoluble state, and cross-linked on the fiber interface into a resin network structure that cannot be completely destroyed by water, thereby protecting the fibers from water swelling, so that the paper plastic products have wet strength, and also give the paper plastic products a certain dry strength.

[0018] The present invention also provides a method for preparing a degradable paper-plastic material, comprising the following steps:

[0019] (1) soaking a plant fiber pulp sheet in water and then crushing it to obtain a plant fiber slurry;

[0020] (2) uniformly mixing the plant fiber slurry obtained in step (1) with an auxiliary agent and water to obtain a mixed slurry; the mass concentration of the absolute dry slurry in the mixed slurry is 0.4-1%; the auxiliary agent comprises at least one of a sizing agent, an oil-proofing agent, a dry strength agent, and a wet strength agent;

[0021] (3) subjecting the mixed slurry obtained in step (2) to vacuum dehydration to form a primary embryo;

[0022] (4) drying the embryo obtained in step (3) and subjecting it to heat pressing and shaping treatment to obtain a semi-finished product; the humidity of the semi-finished product is less than 10%;

[0023] (5) The semi-finished product obtained in step (4) is shaped and trimmed to obtain a degradable paper-plastic material.

[0024] The raw materials prepared by the present invention are sequentially prepared through pulping, slurry adjustment, molding, hot pressing and shaping to prepare the degradable paper-plastic material. In the preparation method, the concentration of the mixed slurry in step (2) needs to be adjusted to within the range of 0.4-1%. If the slurry concentration is too low, the material cannot be formed and the material strength is reduced; if the slurry concentration is too high, the thickness of the product cannot be controlled uniformly and the material is uneven; when the concentration range is within the range of 0.4-1%, the thickness of the material is uniform from top to bottom, and the strength can be adjusted by the concentration to prepare products with different strengths. In step (4) of the preparation method, after the primary embryo is dried, it needs to be hot pressed to a humidity of less than 10%. If it exceeds 10%, the product is easy to soften and deform due to too much moisture. The preparation method of the present invention is simple and low in cost. The surface of the obtained material is smooth and beautiful. The material has high strength and good waterproof and moisture-proof properties. It is a completely degradable material.

[0025] As a preferred embodiment of the present invention, in step (1), the length of the plant fibers in the slurry obtained by the crushing is 0.45 μm-1.2 mm.

[0026] The inventors have found through research that if the length of the plant fiber in the slurry obtained by crushing is too short, it will lack interweaving force, and the surface of the product after molding will be smooth, but it will have no strength and will be fragile; if the fiber is too long, the product will have strength after molding, but the surface will be rough, uneven and not smooth, and some products with deeper structures will be easily torn, so the proportion should be based on the structure of the product. Fibers generally lack interweaving force if they are less than 45μm, and the strength of the product after molding is insufficient. Fibers larger than 1.2mm will have a rough surface after molding, and the product will be easily torn, affecting the appearance of the product.

[0027] As a preferred embodiment of the present invention, in step (1), the length of the plant fibers in the slurry obtained by the crushing is 0.5-1 mm.

[0028] As a preferred embodiment of the present invention, in step (2), the mass concentration of the absolute dry pulp in the mixed slurry is 0.5-0.8%.

[0029] The inventors have found through research that the slurry concentration entering the forming slurry tank is generally about 0.5-0.8%. If the slurry concentration is too high, the thickness of the product will be uneven, resulting in a phenomenon of thin top and thick bottom, increasing the weight of the product and wasting materials. If the slurry concentration is too low, the product strength will be insufficient, and the product will be easily broken and damaged.

[0030] As a preferred embodiment of the present invention, in step (4), the hot pressing and shaping conditions are: upper mold temperature 185-195°C, lower mold temperature 180-190°C, hot pressing time 60-80s, and air pressure 7-9Mpa.

[0031] The present invention also provides the use of any of the above-mentioned degradable paper-plastic materials in the production of various packaging boxes and electronic cigarette tubes; the packaging boxes include glasses boxes.

[0032] The inventor has found through research that there are many types of packaging boxes, especially glasses boxes, mainly including iron boxes, plastic boxes, aluminum boxes, EVA boxes, soft bags, etc. The materials used are mostly iron, aluminum, leather, flocking, ABS, PP, cloth, etc. Taking the most common iron glasses box as an example, the manufacturing process includes: cutting, die casting, punching, gluing, pressing, hinge installation, hinge punching, glue spraying, sticking, packaging and other steps. Although the iron glasses box has good strength, its production process is cumbersome, the product cost is high, and it cannot be naturally degraded in the environment after being discarded, causing great waste of resources and environmental pollution. At present, most of the environmentally friendly paper packaging boxes and glasses boxes used as alternatives are disposable products, which cannot meet the requirements of repeated use, and have insufficient strength and are not water-resistant and moisture-resistant. The packaging box and glasses box prepared by the degradable paper-plastic material of the present invention have simple process and low cost, and the product can be reused, and has sufficient strength and water-resistant and moisture-resistant properties. At the same time, the degradable paper-plastic material of the present invention can also be used as an electronic cigarette shell material. At present, the mainstream electronic cigarette shell materials are metal, plastic, etc. The shell processing process is complicated, and the labor cost and material cost are increased; the metal shell will increase the weight of the electronic cigarette itself, and it lacks texture and feels cold when touched; and although the plastic shell does not feel cold to the touch, the overall strength of the plastic shell is not enough. When the electronic cigarette accidentally falls on the ground, it is easy to break the plastic shell and cause the product to be scrapped. The electronic cigarette shell prepared by the degradable paper-plastic material of the present invention has a good touch, light weight, and high strength, which effectively overcomes the shortcomings of the current application of metal and plastic materials to electronic cigarette tubes.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The degradable paper-plastic material of the present invention is a completely degradable material with a simple manufacturing process and low cost.

[0035] (2) The surface of the degradable paper-plastic material of the present invention is smooth and beautiful, and the material has high strength and good waterproof and moisture-proof properties.

[0036] (3) The degradable paper-plastic material of the present invention has good plasticity and can be used to manufacture various packaging boxes and electronic cigarette tubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the natural degradation diagram of Example 2 of the present invention.

[0038] Figure 2 This is a packaging box diagram of Example 1 of the present invention.

[0039] Figure 3 This is a diagram of a glasses case according to embodiment 5 of the present invention.

[0040] Figure 4This is a diagram of an electronic cigarette tube according to embodiment 6 of the present invention. DETAILED DESCRIPTION

[0041] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention will be further described below in conjunction with specific examples. The experimental methods described in the examples are conventional methods unless otherwise specified; the reagents and materials described can be obtained from commercial sources unless otherwise specified.

[0042] The raw material information used in the examples and comparative examples of the present invention is shown in Table 1.

[0043] Table 1 Raw material information of Examples 1-6 and Comparative Examples 1-4

[0044] Raw material types Raw material name Raw material grade Raw material manufacturers Sizing agent Alkyl ketene dimer SH-1302644 Sanshi Biotechnology Dry strength agent Cationic starch 936 Grass Pulp Enhanced Starch Dongmei Wet Strength Agent Polyamide epichlorohydrin resin Industrial Grade Sanshi Biotechnology

[0045] Example 1

[0046] Example 1 is an example of using the degradable paper-plastic material of the present invention to make a product packaging box. The degradable paper-plastic material used in the packaging box includes the following raw materials in weight percentage: 94% plant fiber pulp board, 3% alkyl ketene dimer as a sizing agent, 2% cationic starch as a dry strength agent, and 1% polyamide epichlorohydrin resin as a wet strength agent.

[0047] The specific method for preparing a product packaging box includes the following steps: (1) pulping: prepare pulp according to the ratio of wood pulp and sugarcane pulp of 6:4, soak for 15-20 minutes and put into a pulping machine; (2) pulping: inject clean water to break the pulp board into 0.5mm-1mm fibers, and pump it into a pulping barrel; add additives to the pulp pool in the pulping barrel and mix them evenly, and add water to adjust the pulp pool concentration to about 0.6%, and pump it into a pulp storage barrel. (3) molding: a vacuum molding machine absorbs wood pulp fibers into a mold, dehydrates, forms a primary embryo, and places the primary embryo on a grid to dry; (4) hot pressing and shaping: put the primary embryo into the mold of a hot pressing shaping machine, the upper mold temperature is 185-195°C, the lower mold temperature is 180-190°C, the hot pressing time is 60-80s, the air pressure is 7-9Mpa, remove moisture, and the product humidity is less than 10%; (5) shaping and trimming; (6) assembly.

[0048] Example 2

[0049] Example 2 is an example of using the degradable paper-plastic material of the present invention to make a product packaging box. The degradable paper-plastic material used in the packaging box includes the following raw materials in weight percentage: 95.5% plant fiber pulp board, 1.5% alkyl ketene dimer as a sizing agent, 1% cationic starch as a dry strength agent, and 2% polyamide epichlorohydrin resin as a wet strength agent.

[0050] The specific method for preparing a product packaging box includes the following steps: (1) pulping: prepare pulp according to the ratio of wood pulp and sugarcane pulp of 5:5, soak for 15-20 minutes and put into a pulper; (2) pulping: inject clean water to break the pulp board into 0.5mm-1mm fibers, and pump it into a pulping barrel; add additives to the pulp pool in the pulping barrel and mix them evenly, and add water to adjust the pulp pool concentration to about 0.8%, and pump it into a pulp storage barrel. (3) molding: a vacuum molding machine absorbs wood pulp fibers into a mold, dehydrates, forms a primary embryo, and places the primary embryo on a grid to dry; (4) hot pressing and shaping: put the primary embryo into the mold of a hot pressing shaping machine, the upper mold temperature is 185-195°C, the lower mold temperature is 180-190°C, the hot pressing time is 60-80s, the air pressure is 7-9Mpa, remove moisture, and the product humidity is less than 10%; (5) shaping and trimming; (6) assembly.

[0051] Example 3

[0052] Example 3 is an example of using the degradable paper-plastic material of the present invention to make a product packaging box. The degradable paper-plastic material used in the packaging box includes the following raw materials in weight percentage: 95% plant fiber pulp board, 2% alkyl ketene dimer as a sizing agent, 1.5% cationic starch as a dry strength agent, and 1.5% polyamide epichlorohydrin resin as a wet strength agent.

[0053] The specific method for preparing a product packaging box includes the following steps: (1) pulping: prepare pulp according to the ratio of wood pulp and sugarcane pulp of 7:3, soak for 15-20 minutes and put into a pulping machine; (2) pulping: inject clean water to break the pulp board into 0.5mm-1mm fibers, and pump it into a pulping barrel; add additives to the pulp pool in the pulping barrel and mix them evenly, and add water to adjust the pulp pool concentration to about 1%, and pump it into a pulp storage barrel. (3) molding: a vacuum molding machine absorbs wood pulp fibers into a mold, dehydrates, forms a primary embryo, and places the primary embryo on a grid to dry; (4) hot pressing and shaping: put the primary embryo into the mold of a hot pressing shaping machine, the upper mold temperature is 185-195°C, the lower mold temperature is 180-190°C, the hot pressing time is 60-80s, the air pressure is 7-9Mpa, remove moisture, and the product humidity is less than 10%; (5) shaping and trimming; (6) assembly.

[0054] Example 4

[0055] Example 4 is an example of using the degradable paper-plastic material of the present invention to make a product packaging box. The degradable paper-plastic material used in the packaging box includes the following raw materials in weight percentage: 95% plant fiber pulp board, 2% alkyl ketene dimer as a sizing agent, 1.5% cationic starch as a dry strength agent, and 1.5% polyamide epichlorohydrin resin as a wet strength agent.

[0056] The specific method for preparing a product packaging box includes the following steps: (1) pulping: prepare pulp according to the ratio of wood pulp and sugarcane pulp of 5:5, soak for 15-20 minutes and put into a pulper; (2) pulping: inject clean water to break the pulp board into 0.5mm-1mm fibers, and pump it into a pulping barrel; add additives to the pulp pool in the pulping barrel and mix them evenly, and add water to adjust the pulp pool concentration to about 0.4%, and pump it into a pulp storage barrel. (3) molding: a vacuum molding machine absorbs wood pulp fibers into a mold, dehydrates, forms a primary embryo, and places the primary embryo on a grid to dry; (4) hot pressing and shaping: put the primary embryo into the mold of a hot pressing shaping machine, the upper mold temperature is 185-195°C, the lower mold temperature is 180-190°C, the hot pressing time is 60-80s, the air pressure is 7-9Mpa, remove moisture, and the product humidity is less than 10%; (5) shaping and trimming; (6) assembly.

[0057] Example 5

[0058] Example 5 is an example of using the degradable paper-plastic material of the present invention to make a glasses case. The degradable paper-plastic material used in the glasses case includes the following raw materials in weight percentage: 95% plant fiber pulp board, 2% alkyl ketene dimer as a sizing agent, 1.5% cationic starch as a dry strength agent, and 1.5% polyamide epichlorohydrin resin as a wet strength agent.

[0059] The specific preparation method of the eyeglass case includes the following steps: (1) pulping: prepare pulp according to the ratio of wood pulp and sugarcane pulp of 5:5, soak for 15-20 minutes and put into the pulping machine; (2) pulping: inject clean water to break the pulp board into 0.5mm-1mm fibers, and pump it into the pulping barrel; add additives to the pulp pool of the pulping barrel and mix them evenly, and add water to adjust the pulp pool concentration to about 0.5%, and pump it into the pulp storage barrel. (3) molding: the vacuum molding machine absorbs the wood pulp fiber into the mold, dehydrates it, forms a preliminary embryo, and places the preliminary embryo on the grid to dry; (4) hot pressing and shaping: put the preliminary embryo into the mold of the hot pressing shaping machine, the upper mold temperature is 185-195℃, the lower mold temperature is 180-190℃, the hot pressing time is 60-80s, the air pressure is 7-9Mpa, remove moisture, and the product humidity is less than 10%; (5) shaping and trimming; (6) assembly.

[0060] Example 6

[0061] Example 6 is an example of using the degradable paper-plastic material of the present invention to make an electronic cigarette pipe. The degradable paper-plastic material used in the packaging box includes the following raw materials in weight percentage: 90% plant fiber pulp board, 2% alkyl ketene dimer as a sizing agent, 5% perfluoroalkyl compound as an oil-proofing agent, 1.5% cationic starch as a dry strength agent, and 1.5% polyamide epichlorohydrin as a wet strength agent.

[0062] The specific preparation method of the electronic cigarette pipe includes the following steps: (1) pulping: prepare pulp according to the ratio of wood pulp and sugarcane pulp of 5:5, soak for 15-20 minutes and put into the pulper; (2) pulping: inject clean water to break the pulp board into 0.5mm-1mm fibers, and pump it into the pulping barrel; add additives to the pulp pool of the pulping barrel and mix them evenly, and add water to adjust the pulp pool concentration to about 0.5%, and pump it into the pulp storage barrel. (3) molding: the vacuum molding machine absorbs the wood pulp fiber into the mold, dehydrates it, forms a preliminary embryo, and places the preliminary embryo on the grid to dry; (4) hot pressing and shaping: put the preliminary embryo into the mold of the hot pressing shaping machine, the upper mold temperature is 185-195℃, the lower mold temperature is 180-190℃, the hot pressing time is 60-80s, the air pressure is 7-9Mpa, remove moisture, and the product humidity is less than 10%; (5) shaping and trimming; (6) assembly.

[0063] The present invention specifically adds an oil-proof agent to the electronic cigarette tube to improve the physical strength and oil-proof performance of the finished electronic cigarette tube, meet the need to prevent grease from penetrating when the electronic cigarette tube contacts the skin and overcome the risk of falling and damage.

[0064] Comparative Example 1

[0065] Comparative Example 1 is a comparative example of using the degradable paper-plastic material of the present invention to make a product packaging box. Comparative Example 1 is different from Example 1 in that the pulp is prepared in a ratio of 8:2 between wood pulp and sugarcane pulp, and the pulp board is broken into 1.2-1.8 mm fibers. Other raw materials and preparation methods are the same as those of Example 2.

[0066] Comparative Example 2

[0067] Comparative Example 2 is a comparative example of using the degradable paper-plastic material of the present invention to make a product packaging box. Comparative Example 1 is different from Example 1 except that the pulp is prepared in a ratio of 2:8 between wood pulp and sugarcane pulp, and the pulp board is broken into fibers of 0.1-0.45 μm. Other raw materials and preparation methods are the same as those of Example 2.

[0068] Comparative Example 3

[0069] Comparative Example 3 is a comparative example of using the degradable paper-plastic material of the present invention to make a product packaging box. Comparative Example 1 is different from Example 2 except that the pulp pool concentration is adjusted to 1.1% by adding water to the pulp mixing barrel. Other raw materials and preparation methods are the same as those of Example 2.

[0070] Comparative Example 4

[0071] Comparative Example 4 is a comparative example of using the degradable paper-plastic material of the present invention to make a product packaging box. Comparative Example 1 is different from Example 2 except that the pulp pool concentration is adjusted to 0.3% by adding water to the pulp mixing barrel. Other raw materials and preparation methods are the same as those of Example 2.

[0072] The inventors conducted drop and pressure resistance tests on the packaging boxes prepared in Examples 1-6 and Comparative Examples 1-4. The specific test methods are as follows:

[0073] Drop test: Drop the sample freely with the bottom facing downward from a height of 80cm above a 60×60cm flat steel plate to observe whether the sample is intact. Each sample is tested 3 times. If there is no damage after 3 tests, the product is considered qualified.

[0074] Pressure resistance test: Place the sample at the center of the lower pressure plate of the pressure testing machine, select the stacking mode, set the initial load to 100N, the stacking strength to 830N, the stacking time to 5 minutes, the test speed to 10mm / min, start the test, and the instrument automatically completes the test process according to the set parameters. The product is qualified if the deformation is ≤3mm under the pressure of 830N.

[0075] Waterproof test: Fill the product with water and place it naturally indoors for 30 minutes. The product is qualified if there is no water absorption, no penetration, and no softening.

[0076] Moisture-proof test: The product is placed in a constant temperature oven at 70 degrees for 60 minutes and weighed, and then placed in a 90% humidity state for 2 hours and weighed. The qualified humidity is within 10%. The formula is: s = (1-M0 / M1) x 100%, M0 is the mass before the test, M1 is the mass after the test, and S is the moisture-proof degree.

[0077] Table 2 Comprehensive performance test results of Examples 1-6 and Comparative Examples 1-4

[0078]

[0079]

[0080] Comprehensive performance tests show that by controlling the ratio and degree of crushing of plant fibers in the slurry, when the fiber length is between 0.5-1mm, the product has both smooth appearance and good strength. When the fiber length is less than 45μm, there is a lack of interweaving force, and the strength of the product after forming is insufficient. When the fiber length is greater than 1.2mm, the surface of the product after forming is rough, and the product is easy to tear, affecting the appearance of the product. The slurry concentration entering the forming slurry tank is preferably about 0.5-0.8%. If the slurry concentration is too high, the thickness of the product will be uneven, resulting in a phenomenon of thin top and thick bottom, increasing the weight of the product and wasting materials. If the slurry concentration is too low, the product strength will be insufficient, and the product will be easy to break and damage. In Examples 1-3 and 5-6 of the present invention, the control of dry strength agent, wet strength agent and fiber concentration can ensure that the product is deformed ≤3mm under a pressure of 830N, meeting the needs of the packaging box. The embodiments of the present invention can ensure the waterproof and moisture-proof properties of the product by regulating the sizing agent and the wet strength agent, and can be flexibly adjusted according to the needs of specific products.

[0081] Figure 1 This is a diagram of the natural degradation process of Example 2 of the present invention in an outdoor open-air environment. As can be seen from the figure, the packaging box of the present invention begins to decompose in 30 days and can be basically decomposed in 120 days. Compared with traditional packaging boxes made of difficult-to-degrade materials such as plastics, the packaging box of the present invention can be quickly and completely decomposed in a natural environment. The present invention has low cost, simple preparation process, excellent and adjustable comprehensive performance of materials, and is suitable for use in the production of various packaging boxes, glasses cases, and electronic cigarette tubes.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a degradable paper-plastic material, characterized in that: The steps include: (1) Soaking a plant fiber pulp sheet in water and then crushing it to obtain a plant fiber slurry; (2) uniformly mixing the plant fiber slurry obtained in step (1) with an auxiliary agent and water to obtain a mixed slurry; the mass concentration of the absolute dry slurry in the mixed slurry is 0.4-1%; the auxiliary agent comprises at least one of a sizing agent, an oil-proofing agent, a dry strength agent, and a wet strength agent; (3) subjecting the mixed slurry obtained in step (2) to vacuum dehydration to prepare a primary embryo; (4) drying the embryo obtained in step (3) and subjecting it to heat pressing and shaping treatment to obtain a semi-finished product; the humidity of the semi-finished product is less than 10%; (5) shaping and trimming the semi-finished product obtained in step (4) to obtain a degradable paper-plastic material; In step (1), the length of the plant fibers in the slurry obtained by the crushing is 0.45 μm-1.2 mm; The degradable paper-plastic material comprises the following raw materials in weight percentage: 90-95.5% of plant fiber pulp board, 1.5-3% of sizing agent, 0-5% of oil-proof agent, 1-2% of dry strength agent, and 1-2% of wet strength agent; the plant fiber pulp board comprises wood pulp board and sugarcane pulp board; the mass ratio of the wood pulp board to the sugarcane pulp board is (5-7): (3-5).

2. The preparation method according to claim 1, characterized in that: The preparation comprises the following raw materials in percentage by weight: 90-95.5% of plant fiber pulp board, 1.5-2% of sizing agent, 0-5% of oil-proofing agent, 1-1.5% of dry strength agent and 1.5-2% of wet strength agent.

3. The preparation method according to claim 1, characterized in that: The oil-proof agent includes at least one of perfluorooctanoate, perfluorooctane sulfonyl compounds, alkylphenol polyoxyethylene ethers, and perfluorohexane sulfonyl compounds; the sizing agent includes at least one of alkyl ketene dimer, alkenyl succinic anhydride, rosin sizing agent, and paraffin sizing agent; the dry strength agent includes at least one of cationic starch, anionic starch, and ionic polyacrylamide; the wet strength agent includes at least one of polyamide epichlorohydrin resin, melamine formaldehyde resin, and urea formaldehyde resin.

4. The preparation method according to claim 1, characterized in that: In step (1), the length of the plant fibers in the slurry obtained by the crushing is 0.5-1 mm.

5. The preparation method according to claim 1, characterized in that: In step (2), the mass concentration of the absolute dry pulp in the mixed slurry is 0.5-0.8%.

6. The preparation method according to claim 1, characterized in that: In step (4), the hot pressing and shaping conditions are: upper mold temperature 185-195°C, lower mold temperature 180-190°C, hot pressing time 60-80 s, and air pressure 7-9 MPa.

7. Use of the degradable paper-plastic material prepared by the method according to any one of claims 1 to 6 in the production of various packaging boxes and electronic cigarette tubes.

8. The use of the degradable paper-plastic material according to claim 7 in the production of various packaging boxes and electronic cigarette tubes, characterized in that: The packaging box is a glasses box.

Images