Powder packaging lining bag for container and preparation method of powder packaging lining bag

Abstract

The invention relates to the field of packaging bags for transportation, and particularly discloses a powder packaging lining bag for a container and a preparation method of the powder packaging lining bag. The invention discloses a preparation method of a powder packaging lining bag for a container. The preparation method comprises the following steps: co-extruding three layers to obtain a PE base film containing an outer layer, a middle layer and a heat sealing layer which are sequentially overlapped; uniformly spraying a waterproof material on one side of the NiO / SnO2 loaded polyimide nanofiber membrane, and baking at 200-220 DEG C for 4-6 minutes to form a waterproof layer; the heat sealing layer of the PE base film is attached to the side, not sprayed with the waterproof material, of the NiO / SnO2-loaded polyimide nanofiber film, hot-pressing compounding is conducted, and the lining bag is obtained after cutting and bonding are conducted. The lining bag is used for container powder packaging, has the advantages of being good in antistatic and damp-proof effect, does not easily generate static electricity to cause powder adhesion and influence on unloading efficiency, and is good in impact resistance and stretch resistance at the same time.

Description

Technical Field

[0001] The present application relates to the technical field of transport packaging bags, and more specifically, to a powder packaging liner bag for a container and a preparation method thereof. Background Art

[0002] Container liner bags, also known as dry material bags, can transport not only bulk solid particles and powdered products, but also liquid products. Due to their containerized transport, they offer advantages over traditional woven bags and ton bags, including higher unit volume, easier loading and unloading, reduced labor costs, and zero secondary contamination. As a new type of logistics packaging material, container bags have gained widespread application and adoption with the continuous growth of global trade and the rapid development of the logistics industry. Throughout their development, they have consistently pursued the goals of convenience, efficiency, and environmental protection to meet the demands of the modern logistics industry.

[0003] Powders easily absorb moisture in humid environments, causing them to clump, deteriorate, or otherwise degrade in performance. Especially during long transport periods, such as ocean shipping, humidity fluctuations within the container can lead to condensation, further impacting the powder's quality. Therefore, to maintain dryness and maintain its quality, container packaging bags must possess excellent moisture-proof properties. Consequently, during transportation, powders rub against and come into contact with the inner surface of the bag, generating static electricity. This charged powder easily adheres to the inner surface of the bag, and even after the powder is poured out of the liner bag, a layer of powder or powder residue remains statically attached to the bag, affecting the efficiency of powder unloading and making the liner bag's recycling inconvenient. Incomplete cleaning can also contaminate secondary contents.

[0004] Therefore, how to prepare a liner bag with good antistatic and moisture-proof properties during powder transportation is an urgent problem to be solved. Summary of the Invention

[0005] In order to improve the antistatic and moisture-proof properties of container liner bags, the present application provides a powder packaging liner bag for a container and a preparation method thereof.

[0006] In a first aspect, the present application provides a method for preparing a powder packaging liner bag for a container, which adopts the following technical solution: A method for preparing a powder packaging liner bag for a container, comprising the following steps: The PE base film comprising an outer layer, a middle layer and a heat-sealing layer stacked in sequence is produced by three-layer co-extrusion; Evenly spray waterproof material on one side of the NiO / SnO2-loaded polyimide nanofiber membrane and bake it at 200-220°C for 4-6 minutes to form a waterproof layer; The heat-sealing layer of the PE base film is laminated to the side of the polyimide nanofiber membrane loaded with NiO / SnO2 that is not sprayed with waterproof material, and then hot-pressed and laminated. The liner bag is then produced after cutting and bonding.

[0007] By adopting the above technical solution, the PE base film is used as the outermost layer, which has excellent flexibility and good transparency, allowing users to clearly see the status of the materials in the bag and facilitate monitoring and management. In addition, the PE base film is highly durable and not easily damaged. At the same time, it can effectively isolate external pollution, be waterproof and anti-seepage, and ensure the stable quality of materials during transportation and storage.

[0008] SnO2 is an n-type semiconductor material, which enables it to generate charge movement under the action of an electric field and exhibits antistatic properties. Nickel oxide, as a P-type semiconductor material, has a certain conductivity. Nickel oxide is doped with SnO2 and loaded into polyimide nanofibers. Nickel oxide and tin dioxide are used together. The combination of P-type and n-type semiconductors may produce a pn junction, which is conducive to the transfer of electrons, improves the overall conductivity, and reduces the surface resistivity of the material, thereby enhancing the antistatic effect. Using polyimide nanofibers as a carrier, polyimide has It has high strength and high modulus, and its molecular chain contains aromatic rings and imide groups, which give it good tensile strength and toughness, and strong impact resistance and puncture resistance. Therefore, when the liner bag is impacted, it can effectively transmit and disperse the impact force and inhibit crack propagation. Waterproof material is sprayed on the polyimide nanofiber membrane loaded with NiO / SnO2 to form a waterproof coating. The waterproof material can reduce the roughness of the polyimide nanofiber membrane loaded with NiO / SnO2, increase its density and smoothness, reduce material adhesion, and increase the moisture-proof ability of the liner bag.

[0009] Optionally, the molar ratio of nickel to tin in the NiO / SnO2 loaded polyimide nanofiber membrane is 1:1-2.

[0010] By adopting the above technical solution, nickel and tin are combined in an appropriate molar ratio and loaded into the polyimide nanofiber membrane, and the two form an antistatic synergistic effect, thereby enhancing the antistatic ability of the liner bag.

[0011] Optionally, the NiO / SnO2 loaded polyimide nanofiber membrane is prepared by the following method: Adding stannous octoate and nickel nitrate hexahydrate into DMF to prepare a mixed solution; The blended liquid is added to a polyamic acid solution with a concentration of 12-15wt%, stirred evenly to obtain a spinning solution, and the polyamic acid nanofiber membrane is obtained by electrospinning. The polyimide nanofiber membrane is obtained by vacuum drying and thermal imidization. The total amount of stannous octoate and nickel nitrate hexahydrate is 20-30wt% of the mass of the polyamic acid.

[0012] By adopting the above technical scheme, stannous octoate and nickel nitrate hexahydrate are used as raw materials, which are added to a polyamic acid solution and loaded into a polyamic acid nanofiber membrane after electrostatic spinning. During thermal imidization, the polyamic acid forms polyimide, and the orientation of the molecular chain can be rearranged during hot-pressing amination to obtain a polyimide nanofiber membrane with higher mechanical strength. Stannous octoate and nickel nitrate hexahydrate undergo thermal decomposition at the high temperature of hot-pressing amination, releasing gas, thereby further increasing the specific surface area of the polyimide nanofiber membrane and facilitating the filling and bonding of waterproof materials.

[0013] Optionally, the waterproof material includes nano-silicon dioxide, silver nanowires and polyvinylidene fluoride resin in a mass ratio of 0.3-0.5:0.1-0.2:1.

[0014] By adopting the above technical solution, the waterproof material contains nano-silicon dioxide, silver nanowires and polyvinylidene fluoride resin. During baking, the polyvinylidene fluoride resin is hot-melted under high-temperature baking, thereby bonding the nano-silicon dioxide and silver nanowires to the surface of the polyimide nanofiber membrane loaded with NiO / SnO2. The silver nanowires have excellent electrical conductivity, which can further enhance the antistatic effect of the polyimide nanofiber membrane loaded with NiO / SnO2, and also increase its mechanical properties, such as strength and toughness. At the same time, the silver nanowires have good thermal conductivity, which can improve the heat dissipation effect of the liner bag. The particle size of the nano-silicon dioxide is small. After spraying, it can not only effectively fill the gap between the silver nanowires and the polyimide nanofiber membrane loaded with NiO / SnO2, but also reduce the NiO / The roughness of the surface of the polyimide nanofiber membrane containing SnO2 improves the smoothness and flatness of the surface of the nanofiber membrane, reduces defects, and forms a relatively complete waterproof layer. Silica, silver nanowires, and polyvinylidene fluoride make the surface of the nanofiber membrane denser and smoother, thereby blocking the diffusion of water vapor and having a good moisture-proof effect. Moreover, nano-silica can also be used as a bridging material with silver nanowires to improve the adhesion between the nanofiber membrane and the polyvinylidene fluoride resin. Finally, the heat-sealing layer in the PE film is heat-sealed with the unsprayed side of the nanofiber membrane to form an inner lining bag containing an outer layer, a middle layer, a heat-sealing layer, a polyimide nanofiber membrane loaded with NiO / SnO2, and a waterproof layer in sequence. The surface of the waterproof layer is smooth and has a strong antistatic effect, which can reduce the adsorption of powder and improve the unloading efficiency.

[0015] Optionally, the outer layer of the PE-based film contains the following raw materials in parts by weight: 10-20 parts of metallocene PE, 40-60 parts of LLDPE, 30-40 parts of HDPE, 3-6 parts of polyetheretherketone composite fiber, 10-20 parts of moisture-proof filler, 1-2 parts of lubricant, 1-2 parts of compatibilizer, and 0.5-1 part of antioxidant.

[0016] By adopting the above technical solution, LLDPE has excellent comprehensive performance, good tensile and tear strength, and good cold resistance and weather resistance. Metallocene polyethylene refers to polyethylene obtained by catalytic polymerization with a metallocene catalyst. Its relative molecular weight mass distribution is narrow, and its molecular chain is a long branched structure and is evenly distributed. Blending it with LLDPE can improve the strength, toughness and puncture resistance of LLDPE, and can also improve the transparency of the plastic film; polyetheretherketone composite fiber has strong mechanical properties such as tensile strength and puncture resistance, so it can improve its tensile strength and puncture resistance. Moreover, polyetheretherketone composite fiber, as a reinforcing material, may form a physical barrier, increase the density of the membrane, and reduce the penetration path of water molecules. When the polyetheretherketone composite fiber is evenly dispersed in the PE matrix, it can form a "tortuous path", extend the water molecule penetration path, and reduce the penetration rate; moisture-proof filler can increase the waterproof and moisture-proof ability of the PE-based membrane, reduce the impact on the quality of the powder during long-term sea transportation, and maintain the dryness and quality of the powder.

[0017] Optionally, the polyetheretherketone composite fiber is prepared by crushing and cold-pressing polyetheretherketone spinning fibers and PMMA spinning fibers in a mass ratio of 1:1, and then hot-pressing and crushing them at 250 MPa and 160°C.

[0018] By adopting the above technical solution and hot pressing at high temperature, the PMMA nanofibers can be in a viscous flow state and fill the gaps in the polyetheretherketone spun fibers, so that the polyetheretherketone spun fibers have a smoother appearance. The adhesion of PMMA is conducive to the transmission of force inside the polyetheretherketone composite fiber, thereby enhancing its mechanical strength. Under hot pressing, the porosity of the polyetheretherketone composite fiber becomes smaller, the fiber becomes denser, and its resistance to bending, stretching and compression is stronger.

[0019] Optionally, the moisture-proof filler is zirconium phosphate-loaded ZIF-8.

[0020] By adopting the above technical solution, zirconium phosphate has a higher surface charge density, so it is hydrophilic. It is difficult to disperse evenly with LLDPE in the outer layer, which affects the impact resistance of the PE-based membrane. Therefore, its surface needs to be hydrophobic treated. The surface of ZIF-8 is hydrophobic and not easy to hydrolyze. It can not only improve the dispersibility and compatibility of zirconium phosphate with substrates such as LLDPE, reduce interface defects, enhance the density of the membrane, increase the tensile strength and toughness of the membrane, and reduce structural damage caused by external forces, but also serve as a physical barrier to hinder water penetration. Moreover, the pore structure of ZIF-8 can increase the diffusion resistance of water molecules.

[0021] Optionally, the zirconium phosphate-supported ZIF-8 is pretreated with dimethyldiethoxysiloxane.

[0022] By adopting the above technical solution, the zirconium phosphate ZIF-8 particles are small and may agglomerate. Therefore, dimethyldiethoxysiloxane is grafted into the pores of ZIF-8 to further perform hydrophobic treatment on it, thereby improving its dispersibility, reducing agglomeration, and enhancing its barrier ability to water vapor, thereby improving the moisture-proof effect.

[0023] Optionally, the polyetheretherketone composite fiber has a length of 50-100 μm and a diameter of 10-20 μm.

[0024] By adopting the above technical solution, polyetheretherketone composite fibers are added to the outer layer of the PE-based membrane in appropriate sizes, which can enhance the density and impermeability of the outer layer while increasing the tensile strength and puncture resistance of the PE-based membrane.

[0025] Optionally, the compatibilizer is maleic anhydride grafted polyethylene and a silane coupling agent in a mass ratio of 1:1.

[0026] By adopting the above technical solution, maleic anhydride grafted polyethylene can significantly improve the interfacial affinity between LDPE, LLDPE, and HDPE, increase the strength of the outer layer, and can work together with silane coupling agents to improve the compatibility between various types of PE and polyetheretherketone composite fibers and moisture-proof fillers, thereby enhancing the smoothness and density of the outer layer of the PE base film.

[0027] Optionally, the thickness ratio of the PE-based film, the NiO / SnO2-loaded polyimide nanofiber film and the waterproof layer is 1:0.25-1:0.125-0.5.

[0028] In a second aspect, the present application provides a powder packaging liner bag for a container, which adopts the following technical solution: A powder packaging liner bag for a container is manufactured by adopting the preparation method of the powder packaging liner bag for a container.

[0029] In summary, this application has the following beneficial effects: 1. Since this application uses a PE-based film as the outer layer, a polyimide nanofiber membrane loaded with NiO / SnO2 as the middle layer, and a waterproof layer as the inner layer, the NiO and SnO2 in the NiO / SnO2 polyimide nanofiber membrane can cooperate with each other to produce a good antistatic effect, and the waterproof layer serves as the filling layer of the nanofiber membrane, which can improve the surface flatness of the nanofiber membrane, enhance the waterproof and moisture-proof capabilities of the liner bag, and reduce the adhesion of powder.

[0030] 2. In this application, polyetheretherketone composite fibers and moisture-proof fillers, LDPE, LLDPE and HDPE and other raw materials are preferably used to prepare the outer layer of the PE-based membrane. The moisture-proof filler can provide further moisture-proof protection, and the polyetheretherketone composite fibers can increase the puncture resistance of the PE-based membrane. The moisture-proof filler is preferably zirconium phosphate loaded ZIF-8, and ZIF-8 is used to improve the hydrophobicity of zirconium phosphate, increase its compatibility with materials such as LDPE, and enhance the moisture-proof effect. The zirconium phosphate loaded ZIF-8 is treated with dimethyldiethoxysiloxane to reduce the agglomeration of zirconium phosphate-ZIF-8 and further improve its moisture-proof ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the structure of the powder packaging liner bag for container in Example 1 of the present application.

[0032] In the figure: 1. PE base film; 11. Outer layer; 12. Middle layer; 13. Heat sealing layer; 2. Polyimide nanofiber membrane loaded with NiO / SnO2; 3. Waterproof layer. DETAILED DESCRIPTION

[0033] The following examples further illustrate the present application in detail.

[0034] Preparation Examples 1-4 of NiO / SnO2-loaded Polyimide Nanofiber Membrane (2) The polyamic acid solution with a concentration of 98% in the preparation example was selected from Wuhan Huaxiang Kejie Biotechnology Co., Ltd., model number HXKJ2024.

[0035] Preparation Example 1: Stannous octoate and nickel nitrate hexahydrate were added to 100 g of dimethylformamide and stirred at 80° C. for 2 h to prepare a mixed solution in which the molar ratio of nickel to tin was 1:2; The blend was added to a 15 wt% polyamic acid solution (prepared by diluting a 98% polyamic acid solution with DMF), stirred evenly to obtain a spinning solution, and electrospun to obtain a polyamic acid nanofiber membrane. The membrane was vacuum dried at 100°C for 6 h, and then thermally imidized to obtain a NiO / SnO2-loaded polyimide nanofiber membrane (2). The specific thermal imidization process was as follows: heating to 180°C at 10°C / min, keeping warm for 1 h, heating to 250°C at 5°C / min, keeping warm for 1 h, heating to 350°C at 5°C / min, keeping warm for 1 h, heating to 550°C at 10°C / min and calcining for 6 h. The total amount of stannous octoate and nickel nitrate hexahydrate was 30 wt% of the mass of the polyamic acid. During electrospinning, the receiving distance was 21 cm, the propulsion speed was 0.01 mm / min, and the applied voltage was 16 kV.

[0036] Preparation Example 2: Stannous octoate and nickel nitrate hexahydrate were added to 100 g of dimethylformamide and stirred at 80° C. for 2 h to prepare a mixed solution in which the molar ratio of nickel to tin was 1:1; The blend was added to a 12 wt% polyamic acid solution (prepared by diluting a 98% polyamic acid solution with DMF), stirred evenly to obtain a spinning solution, and electrospun to obtain a polyamic acid nanofiber membrane. The membrane was vacuum dried at 100°C for 6 h, and then thermally imidized to obtain a NiO / SnO2-loaded polyimide nanofiber membrane (2). The specific thermal imidization process was as follows: heating to 180°C at 10°C / min, keeping warm for 1 h, heating to 250°C at 5°C / min, keeping warm for 1 h, heating to 350°C at 5°C / min, keeping warm for 1 h, heating to 550°C at 10°C / min and calcining for 6 h. The total amount of stannous octoate and nickel nitrate hexahydrate was 20 wt% of the mass of the polyamic acid. During electrospinning, the receiving distance was 21 cm, the propulsion speed was 0.01 mm / min, and the applied voltage was 16 kV.

[0037] Preparation Example 3: The difference from Preparation Example 1 is that the molar ratio of nickel to tin is 1:0.25.

[0038] Preparation Example 4: The difference from Preparation Example 1 is that nickel nitrate hexahydrate is not added.

[0039] Preparation Example 5-8 of Zirconium Phosphate Supported ZIF-8

[0040] Preparation Example 5: (1) 1 g of zirconium phosphate was added to 50 ml of deionized water, and Tris solution (prepared by mixing 0.5 g of tris(hydroxymethyl)aminomethane and 50 ml of deionized water) was added dropwise for 15 min. After the addition was completed, the mixture was stirred for 5 min and ultrasonicated for 20 min. 1 g of dopamine was added, and the pH was adjusted to 8.5 with 1 M hydrochloric acid. The mixture was stirred for 24 h, centrifuged, and the supernatant was removed. The mixture was washed with deionized water 3 times and freeze-dried to obtain polydopamine-modified zirconium phosphate. (2) Polydopamine-modified zirconium phosphate was added to a solution formed by 0.43 g zinc chloride and 4 ml DMF, stirred evenly, and calcined at 550 °C for 3 h. The mixture was immersed in a solution formed by 0.213 g 2-methylimidazole and 20 ml DMF, ultrasonically treated for 20 min, reacted at 4 MPa, dried at 70 °C for 20 h, cooled, washed three times with anhydrous ethanol, and dried at 60 °C for 12 h to obtain zirconium phosphate-loaded ZIF-8.

[0041] Preparation Example 6: 1 g of zirconium phosphate was added to a solution formed by 0.43 g of zinc chloride and 4 ml of DMF, stirred evenly, and then calcined at 550°C for 3 h. The solution was immersed in a solution formed by 0.213 g of 2-methylimidazole and 20 ml of DMF, ultrasonically treated for 20 min, reacted at 4 MPa, dried at 70°C for 20 h, cooled, washed three times with anhydrous ethanol, and dried at 60°C for 12 h to obtain zirconium phosphate-supported ZIF-8.

[0042] Preparation Example 7: (1) 1 g of zirconium phosphate was added to 50 ml of deionized water, and a triethanolamine solution (prepared by mixing 0.5 g of triethanolamine and 50 ml of deionized water) was added dropwise for 15 min. After the addition was completed, the mixture was stirred for 5 min, ultrasonicated for 20 min, centrifuged, the supernatant was removed, and the mixture was washed with deionized water three times and freeze-dried to obtain modified zirconium phosphate. (2) The modified zirconium phosphate was added to a solution formed by 0.43 g zinc chloride and 4 ml DMF, stirred evenly, and calcined at 550 ° C for 3 h. The mixture was immersed in a solution formed by 0.213 g 2-methylimidazole and 20 ml DMF, ultrasonically treated for 20 min, reacted at 4 MPa, dried at 70 ° C for 20 h, cooled, washed with anhydrous ethanol three times, and dried at 60 ° C for 12 h to obtain zirconium phosphate-loaded ZIF-8.

[0043] Preparation Example 8: (1) 1 g of zirconium phosphate was added to 50 ml of deionized water, and Tris solution (prepared by mixing 0.5 g of tris(hydroxymethyl)aminomethane and 50 ml of deionized water) was added dropwise for 15 min. After the addition was completed, the mixture was stirred for 5 min and ultrasonicated for 20 min. 1 g of dopamine was added, and the pH was adjusted to 8.5 with 1 M hydrochloric acid. The mixture was stirred for 24 h, centrifuged, and the supernatant was removed. The mixture was washed with deionized water for 3 times and freeze-dried to obtain polydopamine-modified zirconium phosphate. (2) Polydopamine-modified zirconium phosphate was added to a solution of 0.43 g zinc chloride and 4 ml DMF, stirred evenly, and calcined at 550 °C for 3 h. The mixture was then immersed in a solution of 0.213 g 2-methylimidazole and 20 ml DMF, ultrasonicated for 20 min, reacted at 4 MPa, dried at 70 °C for 20 h, cooled, washed three times with anhydrous ethanol, and dried at 60 °C for 12 h to obtain zirconium phosphate-supported ZIF-8. (3) Place the zirconium phosphate-loaded ZIF-8 in a vacuum desiccator, add 2 mL of dimethyldiethoxysiloxane to the bottom of the vacuum desiccator, evacuate to vacuum, heat at 85 °C for 0.5 h, and cool to room temperature. Example

[0044] In the embodiment, LLDPE is selected from Sinopec Maoming, model DFDA-7042, LDPE is selected from Sinopec Shanghai, model Q400, HDPE is selected from Yanshan Petrochemical, model 7000M, metallocene PE is selected from Dow, model 5220G, polyetheretherketone is selected from Shanghai Jinsuyu Plastic, model KT-820P, PMMA is selected from DuPont, model 147K, polyvinylidene fluoride is selected from Solvay, model 721, and silver nanowires are selected from Beijing Dekedaojin Technology, model DK-AG-L30.

[0045] Example 1: A powder packaging liner bag for a container, with a thickness of 140 μm, comprising, from the outside to the inside, a PE base film 1, a polyimide nanofiber membrane 2 loaded with NiO / SnO2, and a waterproof layer 3 in contact with each other in sequence, wherein the thickness ratio of the PE base film 1, the polyimide nanofiber membrane 2 loaded with NiO / SnO2, and the waterproof layer 3 is 1:0.5:0.25, and the polyimide nanofiber membrane 2 loaded with NiO / SnO2 is prepared according to Preparation Example 1, and the PE base film 1 comprises an outer layer 11, a middle layer 12, and a heat-sealing layer 13 with a thickness ratio of 1:0.5:0.5, wherein the heat-sealing layer 13 is in contact with the side of the polyimide nanofiber membrane 2 loaded with NiO / SnO2 away from the waterproof layer 3; wherein the heat-sealing layer 13 of the PE base film 1 comprises the following raw materials: 55 g LLDPE and 45 g LDPE; the middle layer 12 comprises the following raw materials: 40 g LLDPE, 30 g HDPE, and 30 g LDPE; the outer layer 11 comprises the following raw materials: 20g metallocene PE, 40g LLDPE, 40g HDPE, 6g polyetheretherketone composite fiber, 20g moisture-proof filler, 2g lubricant, 2g compatibilizer and 1g antioxidant, wherein the moisture-proof filler is zirconium phosphate, the lubricant is polyethylene wax, the compatibilizer comprises maleic anhydride grafted polyethylene and silane coupling agent KH550 in a mass ratio of 1:1, the antioxidant is antioxidant 1010, and the preparation method of polyetheretherketone composite fiber is as follows: polyetheretherketone is added to hexafluoroisopropanol to obtain 5wt% spinning solution A, high voltage electrospinning, voltage of 15KV, receiving distance of 20cm, spinning speed of 4ml / h, to obtain polyetheretherketone spinning fiber; PMMA is dissolved in dimethylformamide and acetone (weight The polyetheretherketone (PEEK) spinning fiber and the PMMA spinning fiber were mixed in a mass ratio of 1:1 and crushed, and then placed in 75% ethanol, mixed and crushed for 10 minutes, filtered and vacuum dried for 12 hours, and cold pressed at 250 MPa for 10 minutes in a flat vulcanizing agent, and then hot pressed at 250 MPa and 160°C for 30 minutes. After cooling, the fiber was cut to obtain a polyetheretherketone (PEEK) composite fiber with a length of 100 μm and a diameter of 20 μm.

[0046] The method for preparing the powder packaging liner bag for container comprises the following steps: The outer layer raw materials are mixed and then extruded and granulated to obtain the outer layer material; the middle layer raw materials are mixed and then extruded and granulated to obtain the middle layer material; the heat sealing layer raw materials are mixed and then extruded and granulated to obtain the heat sealing layer material; The outer layer material, the middle layer material and the heat sealing layer material were subjected to three-layer co-extrusion blow molding to prepare a PE base film 1, and the extrusion temperatures were 175°C, 185°C, 195°C, 220°C, 220°C, 210°C and 210°C respectively; A waterproofing material was evenly sprayed onto one side of the NiO / SnO2-loaded polyimide nanofiber membrane 2 and baked at 200°C for 6 minutes to form a waterproof layer. The waterproofing material was made by grinding polyvinylidene fluoride resin particles. The spraying pressure was 500 bar and the spraying distance was 18 cm. The heat sealing layer 13 of the PE base film 1 is laminated to the side of the NiO / SnO2 polyimide nanofiber membrane 2 that is not sprayed with waterproof material, and the membrane material is prepared by hot pressing. The membrane material is cut and bonded to prepare an inner liner bag. The hot pressing temperature is 190°C, the pressure is 0.4 MPa, and the time is 10s.

[0047] Example 2: A powder packaging liner bag for a container, with a thickness of 110 μm, comprising, from the outside to the inside, a PE base film 1, a polyimide nanofiber membrane 2 loaded with NiO / SnO2, and a waterproof layer 3 in contact with each other in sequence, the thickness ratio of the PE base film 1, the polyimide nanofiber membrane 2 loaded with NiO / SnO2, and the waterproof layer 3 being 1:0.25:0.125, the polyimide nanofiber membrane 2 loaded with NiO / SnO2 being prepared according to Preparation Example 2, the PE base film 1 comprising an outer layer 11, a middle layer 12, and a heat-sealing layer 13 with a thickness ratio of 1:0.5:0.5, wherein the heat-sealing layer 13 is in contact with the side of the polyimide nanofiber membrane 2 loaded with NiO / SnO2 away from the waterproof layer 3; wherein the heat-sealing layer 13 of the PE base film 1 comprises the following raw materials: 70 g LLDPE and 30 g LDPE; the middle layer 12 comprises the following raw materials: 60 g LLDPE, 20 g HDPE, and 20 g LDPE; the outer layer 11 comprises the following raw materials: 10g metallocene PE, 60g LLDPE, 30g HDPE, 3g polyetheretherketone composite fiber, 10g moisture-proof filler, 1g lubricant, 1g compatibilizer and 0.5g antioxidant, wherein the moisture-proof filler is zirconium phosphate, the lubricant is polyethylene wax, the compatibilizer comprises maleic anhydride grafted polyethylene and silane coupling agent KH550 in a mass ratio of 1:1, the antioxidant is antioxidant 1010, and the polyetheretherketone composite fiber is prepared as follows: polyetheretherketone is added to hexafluoroisopropanol to obtain a 5wt% spinning solution A, high-voltage electrospinning, a voltage of 15KV, a receiving distance of 20cm, a spinning speed of 4ml / h, to obtain polyetheretherketone spinning fiber; PMMA is dissolved in dimethylformamide and acetone ( The polyetheretherketone (PEEK) spinning fiber and the PMMA spinning fiber were mixed in a mass ratio of 1:1 and crushed, and then placed in 75% ethanol, mixed and crushed for 10 minutes, filtered and vacuum dried for 12 hours, and cold pressed at 250 MPa for 10 minutes in a flat vulcanizing agent, and then hot pressed at 250 MPa and 160°C for 30 minutes. After cooling, the fiber was cut to obtain a polyetheretherketone (PEEK) composite fiber with a length of 50 μm and a diameter of 10 μm.

[0048] The method for preparing the powder packaging liner bag for container comprises the following steps: The outer layer raw materials are mixed and then extruded and granulated to obtain the outer layer material; the middle layer raw materials are mixed and then extruded and granulated to obtain the middle layer material; the heat sealing layer raw materials are mixed and then extruded and granulated to obtain the heat sealing layer material; The outer layer material, the middle layer material and the heat sealing layer material were co-extruded to obtain a PE base film 1 at extrusion temperatures of 175°C, 185°C, 195°C, 220°C, 220°C, 210°C and 210°C, respectively; A waterproofing material was evenly sprayed onto one side of the NiO / SnO2-loaded polyimide nanofiber membrane 2 and baked at 220°C for 4 minutes to form a waterproof layer 3. The waterproofing material was made by grinding polyvinylidene fluoride resin particles. The spraying pressure was 500 bar and the spraying distance was 18 cm. The heat sealing layer 13 of the PE base film 1 is laminated to the side of the NiO / SnO2 polyimide nanofiber membrane 2 that is not sprayed with waterproof material, and the membrane material is prepared by hot pressing. The membrane material is cut and bonded to prepare an inner liner bag. The hot pressing temperature is 190°C, the pressure is 0.4 MPa, and the time is 10s.

[0049] Example 3: A powder packaging liner bag for a container, with a thickness of 100 μm, comprising, from the outside to the inside, a PE base film 1, a polyimide nanofiber membrane 2 loaded with NiO / SnO2, and a waterproof layer 3 in contact with each other in sequence, wherein the thickness ratio of the PE base film 1, the polyimide nanofiber membrane 2 loaded with NiO / SnO2, and the waterproof layer 3 is 1:1:0.5, and the polyimide nanofiber membrane 2 loaded with NiO / SnO2 is prepared by Preparation Example 1, and the PE base film 1 comprises an outer layer 11, a middle layer 12, and a heat-sealing layer 13 with a thickness ratio of 1:0.5:0.5, wherein the heat-sealing layer 13 is in contact with the side of the polyimide nanofiber membrane 2 loaded with NiO / SnO2 away from the waterproof layer 3; wherein the heat-sealing layer 13 of the PE base film 1 comprises the following raw materials: 65 g LLDPE and 35 g LDPE; the middle layer 12 comprises the following raw materials: 55 g LLDPE, 22 g HDPE, and 23 g LDPE; the outer layer 11 comprises the following raw materials: 15g metallocene PE, 50g LLDPE, 35g HDPE, 5g polyetheretherketone composite fiber, 15g moisture-proof filler, 1.5g lubricant, 1.5g compatibilizer and 0.8g antioxidant, wherein the moisture-proof filler is zirconium phosphate, the lubricant is polyethylene wax, the compatibilizer includes maleic anhydride grafted polyethylene and silane coupling agent KH550 with a mass ratio of 1:1, the antioxidant is antioxidant 1010, and the preparation method of polyetheretherketone composite fiber is as follows: polyetheretherketone is added to hexafluoroisopropanol to obtain 5wt% spinning solution A, high voltage electrospinning, voltage of 15KV, receiving distance of 20cm, spinning speed of 4ml / h, to obtain polyetheretherketone spinning fiber; PMMA is dissolved in dimethylformamide and propylene A spinning solution B with a concentration of 10wt% was prepared in a mixed solution of polyetheretherketone (weight ratio of 1:1), and high-voltage electrospinning was performed with a voltage of 11kV, a receiving distance of 19cm, and a propulsion speed of 2ml / h to obtain PMMA spinning fibers. The polyetheretherketone spinning fibers and PMMA spinning fibers were mixed in a mass ratio of 1:1 and crushed, and then placed in 75% ethanol, mixed and crushed for 10 minutes, filtered and vacuum dried for 12 hours, cold pressed at 250MPa for 10 minutes in a flat vulcanizing agent, and then hot pressed at 250MPa and 160℃ for 30 minutes. After cooling, they were cut to obtain polyetheretherketone composite fibers with a length of 80μm and a diameter of 15μm.

[0050] The method for preparing the powder packaging liner bag for container comprises the following steps: The outer layer raw materials are mixed and then extruded and granulated to obtain the outer layer material; the middle layer raw materials are mixed and then extruded and granulated to obtain the middle layer material; the heat sealing layer raw materials are mixed and then extruded and granulated to obtain the heat sealing layer material; The outer layer material, the middle layer material and the heat sealing layer material were co-extruded to obtain a PE base film 1 at extrusion temperatures of 175°C, 185°C, 195°C, 220°C, 220°C, 210°C and 210°C, respectively; A waterproofing material was evenly sprayed onto one side of the NiO / SnO2-loaded polyimide nanofiber membrane 2 and baked at 210°C for 5 minutes to form a waterproof layer 3. The waterproofing material was made by grinding polyvinylidene fluoride resin particles. The spraying pressure was 500 bar and the spraying distance was 18 cm. The heat-sealing layer 13 of the PE base film 1 is laminated to the side of the polyimide nanofiber membrane 2 loaded with NiO / SnO2 that is not sprayed with waterproof material, and the membrane material is prepared by hot pressing. The membrane material is cut and bonded to prepare an inner liner bag. The hot pressing temperature is 190°C, the pressure is 0.4 MPa, and the time is 10s.

[0051] Example 4: A powder packaging liner bag for a container, which differs from Example 1 in that the polyimide nanofiber membrane 2 loaded with NiO / SnO2 is made by Preparation Example 3.

[0052] Example 5: A powder packaging liner bag for a container, which differs from Example 1 in that the polyimide nanofiber membrane 2 loaded with NiO / SnO2 is made by Preparation Example 4.

[0053] Example 6: A powder packaging liner bag for a container, which differs from Example 1 in that polyetheretherketone composite fiber is not added to the outer layer 11 of the PE base film 1.

[0054] Example 7: A powder packaging liner bag for a container, which differs from Example 1 in that no moisture-proof filler is added to the outer layer 11 of the PE base film 1.

[0055] Example 8: A powder packaging liner bag for a container. The difference from Example 1 is that the waterproof material is made by mixing and grinding nano-silicon dioxide, silver nanowires and polyvinylidene fluoride resin in a mass ratio of 0.5:0.2:1.

[0056] Example 9: A powder packaging liner bag for a container. The difference from Example 1 is that the waterproof material is made by mixing and grinding nano-silicon dioxide, silver nanowires and polyvinylidene fluoride resin in a mass ratio of 0.3:0.1:1.

[0057] Example 10: A powder packaging liner bag for a container. The difference from Example 8 is that the waterproof material is made by mixing silver nanowires and polyvinylidene fluoride resin in a mass ratio of 0.5:1 and then grinding.

[0058] Example 11: A powder packaging liner bag for a container. The difference from Example 8 is that the waterproof material is made by mixing nano-silicon dioxide and polyvinylidene fluoride resin in a mass ratio of 0.2:1 and then grinding.

[0059] Example 12: A powder packaging liner bag for a container. The difference from Example 8 is that the moisture-proof filler is zirconium phosphate-loaded ZIF-8, and the zirconium phosphate-loaded ZIF-8 is prepared by Preparation Example 5.

[0060] Example 11: A powder packaging liner bag for a container, which differs from Example 12 in that the zirconium phosphate-loaded ZIF-8 is prepared according to Preparation Example 6.

[0061] Example 12: A powder packaging liner bag for a container. The difference from Example 12 is that the zirconium phosphate-loaded ZIF-8 is prepared according to Preparation Example 7.

[0062] Example 13: A powder packaging liner bag for a container, which differs from Example 12 in that zirconium phosphate-loaded ZIF-8 is prepared according to Preparation Example 8.

[0063] Comparative Example Comparative Example 1: A powder packaging liner bag for a container, which differs from Example 1 in that a polyimide nanofiber membrane with the same thickness as the polyimide nanofiber membrane 2 loaded with NiO / SnO2 is used to replace the polyimide nanofiber membrane 2 loaded with NiO / SnO2. The preparation method of the polyimide nanofiber membrane is as follows: a polyamic acid solution with a concentration of 12wt% (prepared by diluting a polyamic acid solution with a concentration of 98% with DMF) is stirred evenly. The spinning solution was then prepared, and the polyamic acid nanofiber membrane was obtained by electrospinning. The membrane was vacuum dried at 100°C for 6 hours, and then thermal imidization was performed to obtain a polyimide nanofiber membrane. The specific process of thermal imidization was as follows: heating to 180°C at 10°C / min, keeping warm for 1 hour, heating to 250°C at 5°C / min, keeping warm for 1 hour, heating to 350°C at 5°C / min, keeping warm for 1 hour, heating to 550°C at 10°C / min, and calcining for 6 hours. Comparative Example 2: A powder packaging liner bag for a container, which differs from Example 1 in that waterproof material is not sprayed on the polyimide nanofiber membrane 2 loaded with NiO / SnO2, and the heat-sealing layer 13 of the PE base film 1 is hot-pressed and composited with either side of the polyimide nanofiber membrane 2 loaded with NiO / SnO2, with a hot-pressing temperature of 190°C, a pressure of 0.4 MPa, and a time of 10 seconds.

[0064] Comparative Example 3: A powder packaging liner bag for a container, which differs from Example 1 in that the liner bag is not provided with a polyimide nanofiber membrane 2 loaded with NiO / SnO2, and the waterproof material is sprayed on the heat-sealing layer 13 of the PE base film 1. The waterproof coating is a polyvinylidene fluoride solution with a concentration of 3wt%, and is dried at 80°C for 10 hours.

[0065] Comparative Example 4: A commercially available PE container liner bag was selected from Gaoqing Ausent container packaging materials, with a thickness of 150 μm.

[0066] Performance testing Liner bags were prepared according to the methods in the examples and comparative examples, and performance tests were performed according to the following methods. The test results are recorded in Table 1.

[0067] 1. Puncture resistance: Tested in accordance with the method specified in GB / T10048-2008 "Plastic composite films and bags for packaging - Dry lamination and extrusion lamination", with a test speed of 300 mm / min.

[0068] 2. Surface resistivity of one side of the waterproof layer 3: The test shall be carried out in accordance with the provisions of GB / T1410-89 "Test method for volume resistivity and surface resistivity of solid insulating materials" under the specified ambient temperature and relative humidity conditions.

[0069] 3. Moisture-proof ability: Add dried silica gel desiccant into the inner liner bag at an amount of 50% of the inner liner bag volume. Record the weight of the silica gel desiccant, which is M0. Seal the inner liner bag and place it in an environment with a temperature of 40°C and a relative humidity of 90%. After 40 days, remove the silica gel desiccant and weigh its mass, which is recorded as M1. Calculate the growth rate of the silica gel desiccant according to (M1-M0) / M0×100%.

[0070] 4. Adhesion amount: Use a 1 / 1000 electronic balance to weigh the mass of the liner bag, which is M0. Fill the liner bag with salt, the filling amount is 95% of the volume of the liner bag, and place the liner bag filled with salt on a vibration table. Vibrate at 2000Hz for 60 minutes to simulate the oscillation of the liner bag during transportation. Then pour out the salt and weigh the mass of the liner bag, which is M1. Calculate the adhesion amount of salt according to M1-M0.

[0071] Table 1 Performance test of powder packaging liner bags for containers

[0072] Combining the data in Table 1 and the selection and dosage of raw materials in Examples 1-3, it can be seen that the liner bags prepared in Examples 1-3 have strong puncture resistance, and the surface resistivity of one side of the waterproof layer 3 is low, the amount of surface particulate matter adhering is small, and the antistatic effect is good. In addition, after being placed in a humid environment, the moisture-proof ability is strong.

[0073] In Example 4, compared with Example 1, the polyimide nanofiber membrane 2 loaded with NiO / SnO2 prepared in Preparation Example 3 was used. Compared with Preparation Example 1, the molar ratio of Ni and Sn in the polyimide fiber membrane was changed. It can be seen that the surface resistivity of the liner bag prepared thereby increased, the antistatic effect decreased, and the amount of salt attached to one side of the waterproof layer increased, indicating that changing the molar ratio of Ni and Sn will affect the antistatic effect of the polyimide nanofiber membrane 2 loaded with NiO / SnO2 in the liner bag.

[0074] In Example 5, the NiO / SnO2-loaded polyimide nanofiber membrane 2 prepared in Preparation Example 4 was used. Compared with Preparation Example 1, nickel nitrate hexahydrate was not added, that is, the prepared polyimide nanofiber membrane only loaded SnO2, and no NiO was loaded. As can be seen from the data in Table 1, the puncture resistance of the prepared liner bag did not change much, but the antistatic ability decreased significantly.

[0075] Compared with Example 1, Example 6 does not add polyetheretherketone composite fiber to the outer layer 11 of the PE base film 1. As can be seen from the data in Table 1, the puncture resistance of the liner bag is significantly reduced, and the moisture-proof ability is slightly reduced, indicating that the addition of polyetheretherketone composite fiber to the outer layer can effectively improve the puncture resistance of the liner bag and play a certain role in improving the moisture-proof ability of the liner bag.

[0076] In Example 7, compared with Example 1, no moisture-proof filler is added to the outer layer 11 of the PE base film 1. It can be seen that the moisture-proof ability and puncture resistance of the liner bag are reduced, but the anti-static ability does not change much, indicating that the addition of moisture-proof filler can effectively improve the moisture-proof effect of the liner bag and improve the puncture resistance.

[0077] Compared with Example 1, Example 8 and Example 9 use a mixture of nano-silicon dioxide, silver nanowires and polyvinylidene fluoride to make waterproof materials. The data in Table 1 show that the puncture resistance of the liner bags prepared in Example 8 and Example 9 is slightly increased, the moisture-proof ability is enhanced, and the particle attachment amount is slightly decreased.

[0078] Compared with Example 8, Example 10 uses nano-silica and polyvinylidene fluoride resin mixed and then ground to make a waterproof material. Table 1 shows that the surface resistivity of the liner bag prepared in Example 10 increases, the antistatic ability decreases, and the adhesion amount increases, indicating that the spraying of silver nanowires can not only increase the antistatic ability of the liner bag and reduce the adhesion of powder, but also improve the puncture resistance of the liner bag and enhance the moisture-proof ability.

[0079] Compared with Example 8, Example 11 uses a mixture of silver nanowires and polyvinylidene fluoride resin to prepare a waterproof material. The puncture resistance of the liner bag prepared in Example 11 is weakened and the weight gain rate is slightly increased. It can be seen that it can improve the puncture resistance and moisture resistance of the liner bag.

[0080] In Example 12, compared with Example 8, the zirconium phosphate prepared in Preparation Example 5 was used to load ZIF-8. It can be seen that the puncture resistance of the liner bag is enhanced, the weight gain rate of the silica gel desiccant is reduced, and the moisture-proof ability is enhanced.

[0081] In Example 13, compared with Example 12, zirconium phosphate-loaded ZIF-8 was prepared by Preparation Example 6. It can be seen that Tris was not used to strip the zirconium phosphate, and polydopamine was not used to increase the adhesion of ZIF-8. It can be seen that its impact resistance was slightly reduced, and its moisture-proof ability was slightly weakened, indicating that the surface hydrophobic ZIF-8 was synthesized on the stripped zirconium phosphate, which can improve the dispersion of zirconium phosphate in the outer layer, and can serve as a physical barrier to hinder the penetration of moisture, thereby enhancing the moisture-proof effect.

[0082] Compared with Example 12, Example 14 uses the zirconium phosphate prepared in Preparation Example 7 to load ZIF-8. Compared with Preparation Example 5, triethanolamine is used to exfoliate the zirconium phosphate, and polydopamine is not synthesized. The puncture resistance of the liner bag prepared in Example 14 is slightly reduced, and the moisture-proof ability is deteriorated.

[0083] In Example 15, zirconium phosphate-loaded ZIF-8 prepared in Preparation Example 8 was used. Compared with Example 12, when preparing zirconium phosphate-loaded ZIF-8, dimethyldiethoxysiloxane was used for post-treatment. It can be seen that the puncture resistance of the liner bag is slightly increased, and the moisture-proof ability is enhanced.

[0084] In Comparative Example 1, a polyimide nanofilm of the same thickness is used to replace the polyimide nanofiber membrane 2 loaded with NiO / SnO2, that is, NiO and SnO2 are not loaded on the polyamic acid nanofiber. As can be seen from the data in Table 1, the surface resistivity of one side of the inner lining bag waterproof layer 3 increases, the antistatic effect becomes worse, and the amount of salt attached increases significantly.

[0085] In Comparative Example 2, waterproof material was not sprayed on the polyimide nanofiber membrane 2 loaded with NiO / SnO2, and the heat-sealing layer 13 of the PE base film 1 and the polyimide nanofiber membrane 2 loaded with NiO / SnO2 were compositely hot-pressed. The other side of the polyimide nanofiber membrane 2 loaded with NiO / SnO2 was in contact with the powder packaging. It can be seen that the anti-adhesion ability of the inner liner bag to the powder deteriorated and the moisture-proof ability was weakened.

[0086] In Comparative Example 3, waterproof material is sprayed directly on the heat-sealing layer 13 of the PE base film 1. It can be seen that the surface resistivity of the liner bag prepared in Comparative Example 3 is large, the puncture resistance is weakened, the moisture-proof ability is slightly reduced, and the amount of edible particles attached is increased.

[0087] Comparative Example 4 is a commercially available PE liner bag, which has poor antistatic effect and moisture-proof ability. When packaging powder materials, powder adhesion is easily generated, affecting unloading efficiency.

[0088] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing a powder packaging liner bag for a container, characterized in that: The following steps are involved: A PE base film (1) comprising an outer layer (11), a middle layer (12) and a heat-sealing layer (13) stacked in sequence is obtained by three-layer co-extrusion; Evenly spraying a waterproof material onto one side of the NiO / SnO2 loaded polyimide nanofiber membrane (2), and baking at 200-220°C for 4-6 minutes to form a waterproof layer (3); The heat sealing layer (12) of the PE base film (1) is laminated to the side of the polyimide nanofiber film (2) loaded with NiO / SnO2 that is not sprayed with waterproof material, and then hot-pressed and laminated. After cutting and bonding, an inner liner bag is obtained.

2. The method for preparing a powder packaging liner bag for a container according to claim 1, characterized in that: The molar ratio of nickel to tin in the NiO / SnO2 loaded polyimide nanofiber membrane (2) is 1:1-2.

3. The method for preparing a powder packaging liner bag for a container according to claim 2, characterized in that: The NiO / SnO2 loaded polyimide nanofiber membrane (2) is prepared by the following method: Adding stannous octoate and nickel nitrate hexahydrate into DMF to prepare a mixed solution; The blended liquid is added to a polyamic acid solution having a concentration of 12-15 wt%, stirred evenly to obtain a spinning solution, and subjected to electrospinning to obtain a polyamic acid nanofiber membrane, which is then vacuum dried and thermally imidized to obtain a NiO / SnO2-loaded polyimide nanofiber membrane (2), wherein the total amount of stannous octoate and nickel nitrate hexahydrate is 20-30 wt% of the mass of the polyamic acid.

4. The method for preparing a powder packaging liner bag for a container according to claim 1, characterized in that: The waterproof material comprises nano-silicon dioxide, silver nanowires and polyvinylidene fluoride resin in a mass ratio of 0.3-0.5:0.1-0.2:

1.

5. The method for preparing a powder packaging liner bag for a container according to claim 1, characterized in that: The outer layer (11) of the PE-based film (1) comprises the following raw materials in parts by weight: 10-20 parts of metallocene PE, 40-60 parts of LLDPE, 30-40 parts of HDPE, 3-6 parts of polyetheretherketone composite fiber, 10-20 parts of moisture-proof filler, 1-2 parts of lubricant, 1-2 parts of compatibilizer, and 0.5-1 part of antioxidant.

6. The method for preparing a powder packaging liner bag for a container according to claim 5, characterized in that: The moisture-proof filler is zirconium phosphate loaded ZIF-8.

7. The method for preparing a powder packaging liner bag for a container according to claim 6, characterized in that: The zirconium phosphate-supported ZIF-8 is pretreated with dimethyldiethoxysiloxane.

8. The method for preparing a powder packaging liner bag for a container according to claim 5, characterized in that: The polyetheretherketone composite fiber has a length of 50-100 μm and a diameter of 10-20 μm.

9. The method for preparing a powder packaging liner bag for a container according to claim 1, characterized in that: The thickness ratio of the PE-based film (1), the NiO / SnO2-loaded polyimide nanofiber film (2), and the waterproof layer (3) is 1:0.25-1:0.125-0.

5.

10. A powder packaging liner bag for a container, characterized by: The container liner bag is manufactured by the method for preparing the powder packaging liner bag according to any one of claims 1 to 9.

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