Damp-proof oxygen-isolating easy-to-tear packaging bag and preparation method thereof

Abstract

The invention discloses a damp-proof oxygen-isolating easy-to-tear packaging bag and a preparation method thereof, and relates to the technical field of packaging bag preparation, the damp-proof oxygen-isolating easy-to-tear packaging bag comprises a composite packaging bag film, a printing layer, a directional stretching film layer and a packaging bag inner layer, the composite packaging bag film and the printing layer as well as the directional stretching film layer and the packaging bag inner layer are connected through press fit, the printing layer is made of polyethylene tension materials and linear materials and contains 10% of EVA materials, the oriented stretching film layer is a biaxial oriented stretching polyester film, the packaging bag inner layer is a polyethylene layer, and biodegradable agents are added into the printing layer, the oriented stretching film layer and the packaging bag inner layer. By means of the multi-composite manufacturing method, the packaging film has various beneficial characteristics, can be suitable for packaging of various objects, can be biologically degraded and has good environmental protection performance, the pre-pressed V-shaped or laser cutting lines are added, the force needed by tearing is reduced, irregular cracking can be avoided, and the tear resistance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging bag preparation, and particularly relates to a moisture-proof and oxygen-proof easy-to-tear packaging bag and a preparation method thereof. Background Art

[0002] In daily life, the usage amount of packaging bags is quite large. However, the environmental pollution caused by the large-scale use of packaging bags cannot be ignored. With the enhancement of people's environmental protection awareness, the development trend of newly developed plastic packaging films at home and abroad is towards high efficiency, non-toxic, harmless, green environmental protection, good quality, low price, and easy to use.

[0003] Therefore, biodegradable packaging bags have emerged as the times require. Biodegradable packaging bags not only achieve convenience but also protect the environment.

[0004] However, although the existing biodegradable packaging bags achieve the function of environmental protection, to a certain extent, they lose the aesthetics and practicality of packaging bags. Their characteristics can only be used as general packaging bags, unable to carry too much advertising information, and not applicable to some foods or other items with strict requirements for the packaging environment. Summary of the Invention

[0005] The purpose of the present invention is to provide a moisture-proof and oxygen-proof easy-to-tear packaging bag and a preparation method thereof, which are used to solve the problem that although the existing biodegradable packaging bags achieve the function of environmental protection, to a certain extent, they lose the aesthetics and practicality of packaging bags. Their characteristics can only be used as general packaging bags, unable to carry too much advertising information, and not applicable to some foods or other items with strict requirements for the packaging environment.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A moisture-proof and oxygen-proof easy-to-tear packaging bag includes a composite packaging bag film, a printing layer, an orientationally stretched film layer, and an inner packaging bag layer. The composite packaging bag film, the printing layer, the orientationally stretched film layer, and the inner packaging bag layer are connected by lamination.

[0008] Among them, the printing layer is made mainly of polyethylene tensile material and linear material, contains 10% EVA material, the orientationally stretched film layer is a biaxially oriented polyester film, the inner packaging bag layer is a polyethylene layer, and a biodegradable agent is added to the printing layer, the orientationally stretched film layer, and the inner packaging bag layer.

[0009] As a further preferred embodiment of the present invention, the conductive material layer is prepared from the following parts by weight: The main raw materials of the composite packaging bag film by weight are: 30-50 parts by mass of polylactic acid, 0.5-1.5 parts by mass of plasticizer, 0.5-1.5 parts by mass of stabilizer, 0.8-2.0 parts by mass of lubricant, 10-15 parts by mass of filler, and 0.5-0.8 parts by mass of inorganic nanomaterial.

[0010] As a further preferred embodiment of the present invention, the conductive material layer is prepared from the following parts by weight: 70-100 kg of polyvinyl chloride (PVC), 150-200 kg of plasticizer, 0.5-2 kg of heat stabilizer, and 10-12 kg of carbon nanotubes.

[0011] As a further preferred embodiment of the present invention, the main raw materials of the composite packaging bag film by weight are: 20-60 parts by mass of polylactic acid, 0.3-1.8 parts by mass of plasticizer, 0.3-1.8 parts by mass of stabilizer, 0.4-3.5 parts by mass of lubricant, 5-20 parts by mass of filler, and 0.3-1.2 parts by mass of inorganic nanomaterial.

[0012] As a further preferred embodiment of the present invention, the polylactic acid is formed by fermentation and polycondensation of extracts of one or more of starch-containing crops such as corn, wheat, and sugar beet.

[0013] As a further preferred embodiment of the present invention, the plasticizer includes, but is not limited to, one or more of phthalate esters, fatty acid esters, phosphate esters, epoxy esters, chlorine-containing plasticizers, polyesters, and trimellitate esters.

[0014] As a further preferred embodiment of the present invention, the stabilizer includes, but is not limited to, one or more of lead salts, metal soaps, organotin compounds, and butylated hydroxytoluene.

[0015] As a further preferred embodiment of the present invention, the lubricant includes, but is not limited to, one or more of waxes and silicone oils.

[0016] As a further preferred embodiment of the present invention, the filler includes, but is not limited to, one or more of cellulose, graphite, and glass fiber.

[0017] As a further preferred embodiment of the present invention, the inorganic nanomaterial is a mixture of nano-montmorillonite and nano-zinc oxide.

[0018] As a further preferred embodiment of the present invention, the present invention provides a moisture-proof and oxygen-barrier easy-to-tear packaging bag and a preparation method thereof, characterized in that the preparation method comprises the following steps:

[0019] Step 1: Prepare a composite packaging bag film. Weigh the components of polylactic acid, plasticizer, stabilizer, lubricant, filler, and inorganic nanomaterials. Then put the polylactic acid, plasticizer, stabilizer, and lubricant into the mixing hopper and mix them at a temperature of 60 - 80°C with a rotation speed of 1350 r / min. After stirring for 30 - 40 min, a mixture is obtained.

[0020] Step 2: Then, put the mixture into a screw extruder and extrude it into a film at a reaction temperature of 180 - 200°C and a rotation speed of 80 - 120 r / min.

[0021] Step 3: Heat or sputter the inorganic nanomaterials in a vacuum environment to vaporize them. Then spray the gaseous atoms or ions of the inorganic nanomaterials on the surface of the mixed film and condense them on the film to form a nanoscale thin film, thus obtaining the composite packaging bag film.

[0022] Step 4: Then print graphics and texts on one side of the printing layer. Bond the side without graphics and texts of the printing layer with the composite packaging bag film through a laminator. Then laminate a layer of oriented stretching film layer on the side with graphics and texts of the printing layer through a laminator, and laminate a layer of the inner packaging bag on the side of the composite packaging bag film away from the printing layer through a laminator to obtain the packaging bag film.

[0023] Step 5: Make the packaging bag film into a moisture-proof and oxygen-proof easy-to-tear packaging bag through a bag-making machine, and pre-press a V-shaped or laser-scored line at the opening.

[0024] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0025] 1. An easy-to-tear packaging bag with moisture-proof and oxygen-proof functions according to the present invention has various beneficial characteristics through a multi-layer lamination manufacturing method, and can be applied to the packaging of various items. The printing layer has characteristics such as good transparency, oxygen barrier, moisture barrier, bright printing, shiny bag body, being able to highlight the product itself as much as possible, ozone resistance, flame retardancy, etc. The oriented stretching film layer has characteristics such as high transparency, excellent tensile and impact strength, good wear resistance and shape stability, high dielectric properties, high temperature resistance, low moisture absorption, low air permeability, solvent resistance, and chemical barrier properties. The inner packaging bag has characteristics such as moisture-proof, antioxidant, acid and alkali resistance, non-toxic, odorless, and conforms to food packaging hygiene standards. Moreover, the nano-montmorillonite in the inorganic nanomaterials can form a tortuous gas transmission path, greatly increasing the diffusion resistance of gases, thereby improving the gas barrier properties of the packaging bag to gases such as oxygen and carbon dioxide. The nano-zinc oxide in the inorganic nanomaterials can reduce the adsorption and penetration of water vapor.

[0026] 2. A moisture-proof and oxygen-barrier easy-to-tear packaging bag of the present invention can be biodegradable, has good environmental protection, and adds pre-pressed V-shaped or laser scoring lines, reducing the force required for tearing and avoiding irregular cracking, increasing the tear resistance. The printing layer, the oriented stretching film layer, and the inner layer 4 of the packaging bag can be degraded by a biodegradant when discarded on the ground, thereby increasing the environmental protection of the packaging bag. Among them, polylactic acid is a new type of nano-biological and renewable biodegradable material that can be completely degraded into carbon dioxide and water by natural microorganisms under specific conditions and can be directly absorbed by the soil without polluting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic cross-sectional structure diagram of a moisture-proof and oxygen-barrier easy-to-tear packaging bag of the present invention;

[0028] Figure 2 It is a schematic flow diagram of a preparation method of a moisture-proof and oxygen-barrier easy-to-tear packaging bag of the present invention.

[0029] The reference numerals are: 1. Composite packaging bag film; 2. Oriented stretching film layer; 3. Oriented stretching film layer; 4. Inner layer of the packaging bag. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] Embodiment 1

[0032] A moisture-proof and oxygen-barrier easy-to-tear packaging bag includes a composite packaging bag film 1, a printing layer 2, an oriented stretching film layer 3, and an inner layer 4 of the packaging bag. The composite packaging bag film 1, the printing layer 2, the oriented stretching film layer 3, and the inner layer 4 of the packaging bag are connected by pressing.

[0033] Among them, the printing layer 2 is made mainly of polyethylene tensile material and linear material, contains 10% EVA material, and the biaxially oriented film layer 3 is a biaxially oriented polyester film. The inner layer 4 of the packaging bag is a polyethylene layer, and a biodegradant is added to both the printing layer 2, the biaxially oriented film layer 3 and the inner layer 4 of the packaging bag; the composite packaging bag film 1 is the main base material of a moisture-proof and oxygen-barrier easy-to-tear packaging bag, and the printing layer 2 is used for printing product information and picture advertisements. It has good transparency, oxygen barrier, moisture resistance, vivid printing, shiny bag body, can highlight the product itself as much as possible, ozone resistance, flame retardancy and other characteristics. The biaxially oriented film layer 3 is the external protection structure of the entire composite packaging bag, which has high transparency, excellent tensile and impact strength, good wear resistance and shape stability, high dielectric properties, high temperature resistance, low moisture absorption, low air permeability and solvent resistance, chemical barrier properties and other characteristics. The inner layer 4 of the packaging bag is the part in contact with the packaged product, which has moisture resistance, oxidation resistance, acid resistance, alkali resistance, non-toxic, odorless, and conforms to the food packaging hygiene standard. And the printing layer 2, the biaxially oriented film layer 3 and the inner layer 4 of the packaging bag can be degraded when discarded on the ground through the biodegradant, thus increasing the environmental protection of the packaging bag.

[0034] As a preferred embodiment, the main raw materials of the composite packaging bag film 1 by weight are: 30 parts by mass of polylactic acid, 0.5 part by mass of plasticizer, 0.5 part by mass of stabilizer, 0.8 part by mass of lubricant, 10 parts by mass of filler, and 0.5 part by mass of inorganic nanomaterial.

[0035] As a preferred embodiment, polylactic acid includes and is not limited to extracts from one or more of starch-containing crops such as corn, wheat, and sugar beet, etc., and is fermented and polycondensed; further, polylactic acid is a new type of nano-biodegradable and renewable biodegradable material, which can be completely degraded into carbon dioxide and water by natural microorganisms under specific conditions, can be directly absorbed by the soil, and will not pollute the environment.

[0036] As a preferred embodiment, the plasticizer includes and is not limited to one or more of phthalate esters, fatty acid esters, phosphate esters, epoxy esters, chlorine-containing plasticizers, polyesters, and trimellitate esters; further, the plasticizer is used to increase the flexibility and ductility of the composite packaging bag film 1.

[0037] As a preferred embodiment, the stabilizer includes and is not limited to one or more of lead salts, metal soaps, organotin compounds, and butylated hydroxytoluene; further, the stabilizer is used to improve the heat resistance and antioxidant properties of plastics.

[0038] As a preferred embodiment, the lubricant includes and is not limited to one or more of waxes and silicone oils; further, the lubricant is used to reduce friction and heat during the processing of the composite packaging bag film 1.

[0039] As a preferred embodiment, the filler includes and is not limited to one or more of cellulose, graphite, and glass fiber. Further, the filler is used to increase the hardness and stiffness of the composite packaging bag film 1 and reduce costs.

[0040] As a preferred embodiment, the inorganic nanomaterial is a mixture of nano-montmorillonite and nano-zinc oxide. Further, the nano-montmorillonite in the inorganic nanomaterial can form a tortuous gas transmission path, greatly increasing the diffusion resistance of gas, thereby improving the gas barrier properties of the packaging bag against gases such as oxygen and carbon dioxide. And the nano-zinc oxide in the inorganic nanomaterial can reduce the adsorption and penetration of water vapor.

[0041] A preparation method of a moisture-proof and oxygen-barrier easy-tear packaging bag, characterized in that the preparation method comprises the following steps:

[0042] Step 1: Prepare the composite packaging bag film 1, weigh the components of polylactic acid, plasticizer, stabilizer, lubricant, filler, and inorganic nanomaterial, and put the polylactic acid, plasticizer, stabilizer, lubricant, and filler into the mixing hopper, and mix at a temperature of 60 - 80 °C at a rotation speed of 1350 r / min. After stirring for 30 - 40 min, a mixture is obtained;

[0043] Step 2: Then extrude the mixture into a film in a screw extruder at a reaction temperature of 180 - 200 °C and a speed of 80 - 120 r / min;

[0044] Step 3: Heat or sputter the inorganic nanomaterial in a vacuum environment to vaporize it, and then spray the gaseous atoms or ions of the inorganic nanomaterial on the surface of the mixed film and condense on the film to form a nanoscale film, obtaining the composite packaging bag film 1;

[0045] Step 4: Then print graphics and texts on one side of the printing layer 2, and compound the side of the printing layer 2 without graphics and texts with the composite packaging bag film 1 through a compounding machine. Then, press a layer of oriented stretching film layer 3 on the side of the printing layer 2 with graphics and texts through a compounding machine, and press a layer of packaging bag inner layer 4 on the side of the composite packaging bag film 1 away from the printing layer 2 to obtain a packaging bag film;

[0046] Step 5: Make the packaging bag film into a moisture-proof and oxygen-barrier easy-tear packaging bag through a bag-making machine, and pre-press a V-shaped or laser-scored line at the opening.

[0047] Example 2

[0048] A moisture-proof and oxygen-barrier easy-tear packaging bag, comprising a composite packaging bag film 1, a printing layer 2, an oriented stretching film layer 3, and a packaging bag inner layer 4. The composite packaging bag film 1, the printing layer 2, the oriented stretching film layer 3, and the packaging bag inner layer 4 are connected by pressing.

[0049] Among them, the printing layer 2 is made mainly of polyethylene tensile material and linear material, contains 10% EVA material, and the biaxially oriented film layer 3 is a biaxially oriented polyester film. The inner layer 4 of the packaging bag is a polyethylene layer, and a biodegradant is added to both the printing layer 2, the biaxially oriented film layer 3 and the inner layer 4 of the packaging bag; the composite packaging bag film 1 is the main base material of a moisture-proof and oxygen-barrier easy-to-tear packaging bag, and the printing layer 2 is used for printing product information and picture advertisements. It has good transparency, oxygen barrier, moisture-proof, bright printing, shiny bag body, can highlight the product itself as much as possible, ozone resistance, flame retardancy and other characteristics. The biaxially oriented film layer 3 is the external protection structure of the entire composite packaging bag, which has high transparency, excellent tensile and impact strength, good wear resistance and shape stability, high dielectric properties, high temperature resistance, low moisture absorption, low gas permeability and solvent resistance, chemical barrier properties and other characteristics. The inner layer 4 of the packaging bag is the part in contact with the packaged product, which has moisture-proof, antioxidant, acid-resistant, alkali-resistant, non-toxic, odorless, and odorless properties, meets the food packaging hygiene standards, and the printing layer 2, the biaxially oriented film layer 3 and the inner layer 4 of the packaging bag can be degraded when discarded on the ground through the biodegradant, thus increasing the environmental protection of the packaging bag.

[0050] As a preferred embodiment, the main raw materials of the composite packaging bag film 1 by weight are: 40 parts by mass of polylactic acid, 1 part by mass of plasticizer, 1 part by mass of stabilizer, 1.3 parts by mass of lubricant, 12 parts by mass of filler, and 0.6 parts by mass of inorganic nanomaterial.

[0051] As a preferred embodiment, polylactic acid includes, but is not limited to, extracts from one or more of starch-containing crops such as corn, wheat, and sugar beet, and is fermented and polycondensed. Further, polylactic acid is a new type of nano-biological and renewable biodegradable material, which is completely degraded into carbon dioxide and water by natural microorganisms under specific conditions, can be directly absorbed by the soil, and does not pollute the environment.

[0052] As a preferred embodiment, the plasticizer includes, but is not limited to, one or more of phthalate esters, fatty acid esters, phosphate esters, epoxy esters, chlorine-containing plasticizers, polyesters, and trimellitate esters. Further, the plasticizer is used to increase the flexibility and ductility of the composite packaging bag film 1.

[0053] As a preferred embodiment, the stabilizer includes, but is not limited to, one or more of lead salts, metal soaps, organotin compounds, and butylated hydroxytoluene. Further, the stabilizer is used to improve the heat resistance and antioxidant properties of plastics.

[0054] As a preferred embodiment, the lubricant includes, but is not limited to, one or more of waxes and silicone oils. Further, the lubricant is used to reduce friction and heat during the processing of the composite packaging bag film 1.

[0055] As a preferred embodiment, the filler includes and is not limited to one or more of cellulose, graphite, and glass fiber. Further, the filler is used to increase the hardness and stiffness of the composite packaging bag film 1 and reduce costs.

[0056] As a preferred embodiment, the inorganic nanomaterial is a mixture of nano-montmorillonite and nano-zinc oxide. Further, the nano-montmorillonite in the inorganic nanomaterial can form a tortuous gas transmission path, greatly increasing the diffusion resistance of gas, thereby improving the gas barrier properties of the packaging bag against gases such as oxygen and carbon dioxide. And the nano-zinc oxide in the inorganic nanomaterial can reduce the adsorption and penetration of water vapor.

[0057] Step 1: Prepare the composite packaging bag film 1. Weigh the components of polylactic acid, plasticizer, stabilizer, lubricant, filler, and inorganic nanomaterial, and put the polylactic acid, plasticizer, stabilizer, lubricant, and filler into the mixing hopper. Mix at a temperature of 60 - 80 °C at a rotation speed of 1350 r / min, and obtain a mixture after stirring for 30 - 40 min.

[0058] Step 2: Then extrude the mixture into a film in a screw extruder at a reaction temperature of 180 - 200 °C and a speed of 80 - 120 r / min.

[0059] Step 3: Heat or sputter the inorganic nanomaterial in a vacuum environment to vaporize it, and then spray the gaseous atoms or ions of the inorganic nanomaterial on the surface of the mixed film and condense on the film to form a nanoscale film, obtaining the composite packaging bag film 1.

[0060] Step 4: Then print graphics and texts on one side of the printing layer 2, and laminate the side of the printing layer 2 without graphics and texts with the composite packaging bag film 1 through a laminator. Then laminate a layer of oriented stretching film layer 3 on the side of the printing layer 2 with graphics and texts through a laminator, and laminate a layer of packaging bag inner layer 4 on the side of the composite packaging bag film 1 away from the printing layer 2 through a laminator to obtain the packaging bag film.

[0061] Step 5: Make the packaging bag film into a moisture-proof and oxygen-proof easy-to-tear packaging bag through a bag-making machine, and pre-press a V-shaped or laser-engraved score line at the opening.

[0062] Example 3

[0063] A moisture-proof and oxygen-proof easy-to-tear packaging bag, comprising a composite packaging bag film 1, a printing layer 2, an oriented stretching film layer 3, and a packaging bag inner layer 4. The composite packaging bag film 1, the printing layer 2, the oriented stretching film layer 3, and the packaging bag inner layer 4 are connected by lamination.

[0064] Among them, the printing layer 2 is made mainly of polyethylene tensile material and linear material, contains 10% EVA material, and the biaxially oriented film layer 3 is a biaxially oriented polyester film. The inner layer 4 of the packaging bag is a polyethylene layer, and a biodegradant is added to both the printing layer 2, the biaxially oriented film layer 3, and the inner layer 4 of the packaging bag; the composite packaging bag film 1 is the main base material of a moisture-proof and oxygen-barrier easy-to-tear packaging bag, and the printing layer 2 is used to print product information and picture advertisements. It has good transparency, oxygen barrier, moisture barrier, vivid printing, shiny bag body, can highlight the product itself as much as possible, ozone resistance, flame retardancy and other characteristics. The biaxially oriented film layer 3 is the external protection structure of the entire composite packaging bag, which has high transparency, excellent tensile and impact strength, good abrasion resistance and shape stability, high dielectric properties, high temperature resistance, low moisture absorption, low air permeability and solvent resistance, chemical barrier properties and other characteristics. The inner layer 4 of the packaging bag is the part in contact with the packaged product, which has moisture-proof, antioxidant, acid-resistant, alkali-resistant, non-toxic, odorless, and odorless properties, meets the food packaging hygiene standards, and the printing layer 2, the biaxially oriented film layer 3, and the inner layer 4 of the packaging bag can be degraded when discarded on the ground through the biodegradant, thus increasing the environmental protection of the packaging bag.

[0065] As a preferred embodiment, the main raw materials of the composite packaging bag film 1 by weight are: 60 parts by mass of polylactic acid, 1.8 parts by mass of plasticizer, 1.8 parts by mass of stabilizer, 3.5 parts by mass of lubricant, 20 parts by mass of filler, and 1.2 parts by mass of inorganic nanomaterial.

[0066] As a preferred embodiment, polylactic acid includes, but is not limited to, extracts from one or more of starch-containing crops such as corn, wheat, and sugar beet, etc., and is fermented and polycondensed; further, polylactic acid is a new type of nano-biological and renewable biodegradable material, which is completely degraded into carbon dioxide and water by natural microorganisms under specific conditions, can be directly absorbed by the soil, and will not pollute the environment.

[0067] As a preferred embodiment, the plasticizer includes, but is not limited to, one or more of phthalate esters, fatty acid esters, phosphate esters, epoxy esters, chlorine-containing plasticizers, polyesters, and trimellitate esters; further, the plasticizer is used to increase the flexibility and ductility of the composite packaging bag film 1.

[0068] As a preferred embodiment, the stabilizer includes, but is not limited to, one or more of lead salts, metal soaps, organotin compounds, and butylated hydroxytoluene; further, the stabilizer is used to improve the heat resistance and antioxidant properties of the plastic.

[0069] As a preferred embodiment, the lubricant includes, but is not limited to, one or more of waxes and silicone oils; further, the lubricant is used to reduce friction and heat during the processing of the composite packaging bag film 1.

[0070] As a preferred embodiment, the filler includes but is not limited to one or more of cellulose, graphite, and glass fiber. Further, the filler is used to increase the hardness and stiffness of the composite packaging bag film 1 and reduce costs.

[0071] As a preferred embodiment, the inorganic nanomaterial is a mixture of nanometer montmorillonite and nanometer zinc oxide. Further, the nanometer montmorillonite in the inorganic nanomaterial can form a tortuous gas transmission path, greatly increasing the diffusion resistance of gas, thereby improving the gas barrier performance of the packaging bag against gases such as oxygen and carbon dioxide. And the nanometer zinc oxide in the inorganic nanomaterial can reduce the adsorption and penetration of water vapor.

[0072] Step 1: Prepare the composite packaging bag film 1. Weigh the components of polylactic acid, plasticizer, stabilizer, lubricant, filler, and inorganic nanomaterial, and put the polylactic acid, plasticizer, stabilizer, lubricant, and filler into the mixing hopper. Mix at a temperature of 60 - 80°C at a rotation speed of 1350 r / min. After stirring for 30 - 40 min, a mixture is obtained.

[0073] Step 2: Then extrude the mixture into a film in a screw extruder at a reaction temperature of 180 - 200°C and a rotation speed of 80 - 120 r / min.

[0074] Step 3: Heat or sputter the inorganic nanomaterial in a vacuum environment to vaporize it, and then spray the gaseous atoms or ions of the inorganic nanomaterial on the surface of the mixed film and condense it on the film to form a nanoscale film, obtaining the composite packaging bag film 1.

[0075] Step 4: Then print graphics and texts on one side of the printing layer 2, and compound the side of the printing layer 2 without graphics and texts with the composite packaging bag film 1 through a compounding machine. Then, press a layer of oriented stretching film layer 3 on the side of the printing layer 2 with graphics and texts through a compounding machine, and press a layer of the inner layer 4 of the packaging bag on the side of the composite packaging bag film 1 away from the printing layer 2 to obtain the packaging bag film.

[0076] Step 5: Make the packaging bag film into a moisture-proof and oxygen-proof easy-to-tear packaging bag through a bag-making machine, and pre-press a V-shaped or laser-scribed line at the opening.

[0077] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

[0078] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only the specific embodiments. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A tearable packaging bag with moisture-proof and oxygen-barrier properties, characterized in that, It includes a composite packaging bag film (1), a printing layer (2), an oriented stretching film layer (3), and an inner layer of the packaging bag (4). The composite packaging bag film (1), the printing layer (2), the oriented stretching film layer (3), and the inner layer of the packaging bag (4) are connected by pressing: Among them, the printing layer (2) is made mainly of polyethylene tensile material and linear material, contains 10% EVA material, and the oriented stretching film layer (3) is a biaxially oriented polyester film. The inner layer of the packaging bag (4) is a polyethylene layer, and a biodegradable agent is added to both the printing layer (2), the oriented stretching film layer (3), and the inner layer of the packaging bag (4).

2. The moisture-proof and oxygen-barrier tearable packaging bag according to claim 1, wherein The main raw materials of the composite packaging bag film (1) by weight are: 30 - 50 parts by mass of polylactic acid, 0.5 - 1.5 parts by mass of plasticizer, 0.5 - 1.5 parts by mass of stabilizer, 0.8 - 2.0 parts by mass of lubricant, 10 - 15 parts by mass of filler, and 0.5 - 0.8 parts by mass of inorganic nanomaterial.

3. The moisture-proof and oxygen-barrier tearable packaging bag according to claim 2, wherein The main raw materials of the composite packaging bag film (1) by weight are: 20 - 60 parts by mass of polylactic acid, 0.3 - 1.8 parts by mass of plasticizer, 0.3 - 1.8 parts by mass of stabilizer, 0.4 - 3.5 parts by mass of lubricant, 5 - 20 parts by mass of filler, and 0.3 - 1.2 parts by mass of inorganic nanomaterial.

4. A tearable packaging bag with moisture-proof and oxygen-barrier properties according to claim 3, characterized in that, The polylactic acid includes, but is not limited to, extracts from one or more of starch-containing crops such as corn, wheat, and sugar beet, which are fermented and polycondensed.

5. A tearable packaging bag with moisture-proof and oxygen-barrier properties according to claim 3, characterized in that, The plasticizer includes, but is not limited to, one or more of phthalate esters, fatty acid esters, phosphate esters, epoxy esters, chlorine-containing plasticizers, polyesters, and trimellitate esters.

6. A tearable packaging bag with moisture-proof and oxygen-barrier properties according to claim 3, characterized in that, The stabilizer includes, but is not limited to, one or more of lead salts, metal soaps, organotin compounds, and butylated hydroxytoluene.

7. A tearable packaging bag with moisture-proof and oxygen-barrier properties according to claim 3, characterized in that, The lubricant includes, but is not limited to, one or more of waxes and silicone oils.

8. A tearable packaging bag with moisture-proof and oxygen-barrier properties according to claim 3, characterized in that, The filler includes, but is not limited to, one or more of cellulose, graphite, and glass fiber.

9. A tearable packaging bag with moisture-proof and oxygen-barrier properties according to claim 3, characterized in that, The inorganic nanomaterial is a mixture of nano-montmorillonite and nano-zinc oxide.

10. A preparation method of a moisture-proof and oxygen-barrier easy-to-tear packaging bag, which is applied to the moisture-proof and oxygen-barrier easy-to-tear packaging bag described in any one of claims 1-9, and is characterized in that, The preparation method steps are as follows: Step 1: Prepare the composite packaging bag film (1). Weigh the components of polylactic acid, plasticizer, stabilizer, lubricant, filler, and inorganic nanomaterial, and put the polylactic acid, plasticizer, stabilizer, lubricant, and filler into a mixing hopper. Mix at a temperature of 60 - 80 °C at a rotation speed of 1350 r / min, and obtain a mixture after stirring for 30 - 40 min; Step 2: Then extrude the mixture into a film in a screw extruder at a reaction temperature of 180 - 200 °C and a speed of 80 - 120 r / min; Step 3: Heat or sputter the inorganic nanomaterial in a vacuum environment to vaporize it, then spray the gaseous atoms or ions of the inorganic nanomaterial on the surface of the mixed film and condense it on the film to form a nano-scale film, obtaining the composite packaging bag film (1); Step 4: Then print graphics and texts on one side of the printing layer (2), and laminate the side of the printing layer (2) without graphics and texts with the composite packaging bag film (1) through a laminator. Then, laminate an oriented stretching film layer (3) on the side of the printing layer (2) with graphics and texts through a laminator, and laminate an inner packaging bag layer (4) on the side of the composite packaging bag film (1) away from the printing layer (2) through a laminator to obtain a packaging bag film. Step 5: Make the packaging bag film into a moisture-proof and oxygen-proof easy-tear packaging bag through a bag-making machine, and pre-press a V-shaped or laser-scored line at the opening.

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