Refrigerant environment-friendly PE film packaging material and production process thereof
By using modified PE film in refrigerant packaging materials, combined with modified limonite, modified soy protein isolate and modified sorbitol, the problem of poor deformation resistance of existing packaging materials is solved, and higher mechanical properties and water absorption are achieved, and refrigerant leakage is avoided.
Patent Information
- Application Number
- CN202411858172.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-03-07
AI Technical Summary
The existing refrigerant packaging materials have poor deformation resistance and are prone to damage during repeated use, resulting in refrigerant leakage and product losses.
Modified PE film packaging materials, including PE resin, modified limonite, modified soy protein isolate and modified sorbitol, are used to improve the water absorption and mechanical properties of the material through modification treatment.
It significantly improves the deformation resistance of the packaging material, enhances its mechanical properties and water absorption, avoids the leakage of refrigerant, and extends the service life of the packaging material.
Smart Images
Figure CN119570138A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of packaging materials, and in particular relates to an environmentally friendly PE film packaging material for a cold preservation agent and a production process thereof. Background Art
[0002] A refrigerant is a substance used to keep things cold, and is used in applications such as refrigeration and heat preservation. Refrigerants can achieve a cooling effect by absorbing heat, reflecting heat, radiating heat, and so on.
[0003] Refrigerants are often used in cold chain logistics to meet the requirements of low temperature environment during transportation. For example, refrigerants are used in the transportation of edible items such as fruits and seafood to maintain their low temperature and freshness. Refrigerants are also needed in the cold chain logistics transportation of pharmaceuticals such as vaccines to achieve their low temperature requirements. Since refrigerants are solid below the phase change temperature and liquid above the phase change temperature, in order to prevent the refrigerants from changing into liquids and contaminating the refrigerated items during use, packaging materials are required to seal and contain them.
[0004] The existing packaging materials of refrigerants are generally packaged in flexible polyethylene plastic bags, which are common ice bags. However, the existing flexible polyethylene has poor deformation resistance and is prone to breakage during repeated use, causing leakage of the internal refrigerant, thereby causing product loss. Summary of the invention
[0005] The present invention provides an environmentally friendly PE film packaging material for a cold retainer, aiming to solve the above-mentioned problem.
[0006] The present invention is achieved in this way: an environmentally friendly PE film packaging material for a cold preservation agent comprises a PE film layer, wherein the PE film layer comprises the following raw materials in parts by weight: 80-100 parts of PE resin, 10-15 parts of modified limonite, 8-12 parts of modified soy protein isolate, 3-8 parts of modified sorbitol, 1-3 parts of antioxidant, 1-5 parts of antibacterial agent, and 2-4 parts of zinc stearate.
[0007] Preferably, the PE film layer comprises the following raw materials in parts by weight: 85-95 parts of PE resin, 11-14 parts of modified limonite, 9-11 parts of modified soy protein isolate, 4-7 parts of modified sorbitol, 1.5-2.5 parts of antioxidant, 2-4 parts of antibacterial agent, and 2.5-3.5 parts of zinc stearate.
[0008] Preferably, the PE film layer comprises the following raw materials in parts by weight: 90 parts of PE resin, 12.5 parts of modified limonite, 10 parts of modified soy protein isolate, 5.5 parts of modified sorbitol, 2 parts of antioxidant, 3 parts of antibacterial agent, and 3 parts of zinc stearate.
[0009] Preferably, the preparation method of the modified limonite is as follows: take 20-25 parts of limonite by weight, clean the surface, dry and perform preliminary crushing; then place it in a muffle furnace and program the temperature to 800-900°C, roast it at a constant temperature for 2-3h, and grind it to a particle size of 100-200 mesh after cooling; then add 80-100 parts of 25-35vt% hydrochloric acid solution, soak it for 3-5h, filter it, and wash it with deionized water 3 times; then add 80-100 parts of 20-30% sodium chloride solution and 10-20 parts of hydrogen peroxide, stir and mix for 30-50min, filter it and dry it at 60-80°C; then add 6-10 parts of amino acids and 80-100 parts of deionized water, stir and mix it for 1-2h; finally add 3-5 parts of polyethylene glycol, continue to stir and mix it for 40-60min, filter it and dry it at 60-80°C to obtain modified limonite. First, roasting is carried out to remove water in different states in the structure of limonite, making the internal structure loose and porous and increasing the specific surface area. Then, the surface of the limonite is modified by surface corrosion with hydrochloric acid to form a stable porous structure on the surface of the limonite particles. Amino acids are added for modification, and the amino groups in the amino acid molecules can combine with the ions on the limonite sheets to improve the adsorption of water. Finally, polyethylene glycol is added, and the amino groups combined with the limonite are grafted to form a stable three-dimensional network structure, which further improves the adsorption and mechanical properties.
[0010] Preferably, the amino acids include one or more combinations of arginine, glutamic acid, glycine, alanine and serine.
[0011] Preferably, the preparation method of the modified soy protein isolate is as follows: 15-20 parts of soy protein isolate are taken by weight, dissolved in 100-120 parts of deionized water, and then 0.1-0.5 parts of caprolactam are added to obtain a mixed solution, the mixed solution is placed in a preset container, and subjected to an acoustic resonance treatment at 20-25° C. for 20-30 minutes, and then the mixed solution is poured into an aluminum foil bag, and vacuum-sealed with a vacuum packaging machine; the mixed solution in the aluminum foil bag is subjected to electron beam irradiation treatment with a dose of 20-40 kGy, and spray-dried after being taken out to obtain the modified soy protein isolate. By adding caprolactam and coordinating with acoustic resonance treatment, low-frequency, high-acceleration vertical vibration is generated in the container during the acoustic resonance treatment, which produces a uniform shear force field, causing the protein to move rapidly, thereby reducing the aggregation of the protein, improving its molecular stretchability and flexibility, exposing more active groups, and achieving the effect of regulating the spatial structure and surface activity of the protein, increasing the grafting and cross-linking reaction activity of caprolactam and the polar groups of protein molecules, increasing the molecular chain of the protein, and increasing the interaction force between protein molecules. Then, through electron beam irradiation, the cross-linking reaction between the material molecules is further promoted, thereby improving the mechanical properties of soy protein isolate.
[0012] Preferably, the acoustic resonance frequency of the acoustic resonance treatment is 60-70 Hz, the amplitude is 30-40%, and the acceleration is 55-65 g.
[0013] Preferably, the preparation method of the modified sorbitol is as follows: 10-15 parts of sorbitol are taken by weight, 80-100 parts of deionized water are added, and then 2-5 parts of polyvinyl alcohol and 1-3 parts of glycerol are added, the temperature is raised to 60-80°C, stirred for 30-50 minutes, and then dried at 80-100°C for 3-5 hours to obtain the modified sorbitol. By adding polyvinyl alcohol, it is hydrolyzed and cross-linked with sorbitol to form a stable structure, and by adding modified sorbitol, a new hydrogen bond is formed with the polyethylene blending system to improve the mechanical properties of the packaging material.
[0014] Preferably, the antioxidant includes one or more combinations of 168, 1010, and 1076, and the antibacterial agent includes one or more combinations of chitosan, nano zinc dioxide, and curcuminol.
[0015] The present invention also provides a production process of the above-mentioned environmentally friendly PE film packaging material for cold preservation, comprising the following steps: Weigh each raw material according to the ratio; Mixing the raw materials to obtain a premix; The obtained premix is extruded by a twin-screw extruder at 170°C and pelletized by a pelletizer to form plastic masterbatch; Adding the plastic masterbatch into the hopper of the extruder, passing through the screw and the die head to the cooling roller at 185°C to form a film, and then winding it up to obtain the PE film layer; The PE film layers are laminated and cut to obtain the required packaging material.
[0016] Compared with the prior art, the embodiments of the present application have the following beneficial effects: The environmentally friendly PE film packaging material for cold preservation provided by the present invention is prepared by environmentally friendly materials, which is more green and environmentally friendly. Modified limonite, modified soy protein isolate and modified sorbitol are added, which has excellent water absorption and makes the surface of the packaging material free of water. By adding modified limonite, roasting is first performed to remove water in different states in the structure of limonite, making the internal structure loose and porous, increasing the specific surface area, and then the surface of limonite is modified by surface corrosion with hydrochloric acid to form a stable porous structure on the surface of limonite particles. By adding amino acid modification, the amino groups in the amino acid molecules can combine with the ions on the limonite sheets to improve the adsorption of water. Finally, polyethylene glycol is added, and the amino groups combined with the limonite are grafted to form a stable three-dimensional network structure, further improving the adsorption and mechanical properties; By adding modified soy protein isolate, adding caprolactam and coordinating with acoustic resonance treatment, low-frequency, high-acceleration vertical vibration is generated in the container during the acoustic resonance treatment, generating a uniform shear force field, causing the protein to move rapidly, thereby reducing the aggregation of the protein, improving its molecular stretchability and flexibility, exposing more active groups, and achieving the effect of regulating the spatial structure and surface activity of the protein, improving the grafting and cross-linking reaction activity of caprolactam and the polar groups of protein molecules, increasing the molecular chain of the protein, and improving the interaction force between protein molecules. Then, through electron beam irradiation, the cross-linking reaction between the material molecules is further promoted to improve the mechanical properties of soy protein isolate.
[0017] By adding modified sorbitol, polyvinyl alcohol is first added, and hydrolyzed and cross-linked with sorbitol to form a stable structure. By adding modified sorbitol, a new hydrogen bond effect is formed with the polyethylene blending system to improve the mechanical properties of the packaging material. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a production process diagram of an environmentally friendly PE film packaging material for cold preservation provided by the present invention. DETAILED DESCRIPTION
[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.
[0020] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0021] Example 1 The embodiment of the present invention provides an environmentally friendly PE film packaging material for a cold preservation agent, such as Figure 1As shown, it includes a PE film layer, and the PE film layer includes the following raw materials in parts by weight: 80 parts of PE resin, 10 parts of modified limonite, 8 parts of modified soy protein isolate, 3 parts of modified sorbitol, 1 part of antioxidant, 1 part of antibacterial agent, and 2 parts of zinc stearate. The production process of the environmentally friendly PE film packaging material for cold preservation includes the following steps: Weigh each raw material according to the ratio; Mixing the raw materials to obtain a premix; The obtained premix is extruded by a twin-screw extruder at 170°C and pelletized by a pelletizer to form plastic masterbatch; Adding plastic masterbatch into the hopper of the extruder, passing through the screw and die head at 185°C to the cooling roller for casting into a film, and then winding up to obtain the PE film layer; The PE film layers are laminated and cut to obtain the required packaging material.
[0022] The preparation method of the modified limonite is as follows: take 20 parts of limonite by weight, clean the surface, dry and perform preliminary crushing; then place it in a muffle furnace and program the temperature to 800°C, roast it at a constant temperature for 2 hours, and grind it to a particle size of 100 mesh after cooling; then add 80 parts of 25vt% hydrochloric acid solution, soak it for 3 hours, filter it, and wash it with deionized water 3 times; then add 80 parts of 20% sodium chloride solution and 10 parts of hydrogen peroxide, stir and mix for 30 minutes, filter it and dry it at 60°C; then add 6 parts of amino acids and 80 parts of deionized water, stir and mix it for 1 hour; finally add 3 parts of polyethylene glycol, continue to stir and mix it for 40 minutes, filter it and dry it at 60°C to obtain modified limonite.
[0023] Furthermore, the amino acids include arginine, glutamic acid, glycine, alanine, serine and other equal proportions.
[0024] Preferably, the preparation method of the modified soy protein isolate is as follows: 15 parts of soy protein isolate are taken by weight, dissolved in 100 parts of deionized water, and then 0.1 parts of caprolactam are added to obtain a mixed solution, the mixed solution is placed in a preset container, and subjected to an acoustic resonance treatment at 20° C. for 20 minutes, and then the mixed solution is poured into an aluminum foil bag, and vacuum-sealed with a vacuum packaging machine; the mixed solution in the aluminum foil bag is subjected to electron beam irradiation treatment at a dose of 20 kGy, and spray-dried after being taken out to obtain the modified soy protein isolate.
[0025] The acoustic resonance frequency of the acoustic resonance treatment is 60 Hz, the amplitude is 30%, and the acceleration is 55 g.
[0026] In this embodiment, the preparation method of the modified sorbitol is as follows: by weight, 10 parts of sorbitol are taken, 80 parts of deionized water are added, and then 2 parts of polyvinyl alcohol and 1 part of glycerol are added, the temperature is raised to 60° C., stirred for 30 minutes, and then dried at 80° C. for 3 hours to obtain modified sorbitol.
[0027] Preferably, the antioxidant comprises 168, 1010, and 1076 mixed in equal proportions, and the antibacterial agent comprises chitosan, nano zinc dioxide, and curcuminol mixed in equal proportions.
[0028] Example 2 The embodiment of the present invention provides an environmentally friendly PE film packaging material for a cold preservation agent, such as Figure 1 As shown, it includes a PE film layer, and the PE film layer includes the following raw materials in parts by weight: 85 parts of PE resin, 11 parts of modified limonite, 9 parts of modified soy protein isolate, 4 parts of modified sorbitol, 1.5 parts of antioxidant, 2 parts of antibacterial agent, and 2.5 parts of zinc stearate. The production process of the environmentally friendly PE film packaging material for cold preservation includes the following steps: Weigh each raw material according to the ratio; Mixing the raw materials to obtain a premix; The obtained premix is extruded by a twin-screw extruder at 170°C and pelletized by a pelletizer to form plastic masterbatch; Adding the plastic masterbatch into the hopper of the extruder, passing through the screw and the die head to the cooling roller at 185°C to form a film, and then winding it up to obtain the PE film layer; The PE film layers are laminated and cut to obtain the required packaging material.
[0029] The preparation method of the modified limonite is as follows: take 20 parts of limonite by weight, clean the surface, dry and perform preliminary crushing; then place it in a muffle furnace and program the temperature to 800°C, roast it at a constant temperature for 2 hours, and grind it to a particle size of 100 mesh after cooling; then add 80 parts of 25vt% hydrochloric acid solution, soak it for 3 hours, filter it, and wash it with deionized water 3 times; then add 80 parts of 20% sodium chloride solution and 10 parts of hydrogen peroxide, stir and mix for 30 minutes, filter it and dry it at 60°C; then add 6 parts of amino acids and 80 parts of deionized water, stir and mix it for 1 hour; finally add 3 parts of polyethylene glycol, continue to stir and mix it for 40 minutes, filter it and dry it at 60°C to obtain modified limonite.
[0030] Furthermore, the amino acids include arginine, glutamic acid, glycine, alanine, serine and other equal proportions.
[0031] Preferably, the preparation method of the modified soy protein isolate is as follows: 15 parts of soy protein isolate are taken by weight, dissolved in 100 parts of deionized water, and then 0.1 parts of caprolactam are added to obtain a mixed solution, the mixed solution is placed in a preset container, and subjected to an acoustic resonance treatment at 20° C. for 20 minutes, and then the mixed solution is poured into an aluminum foil bag, and vacuum-sealed with a vacuum packaging machine; the mixed solution in the aluminum foil bag is subjected to electron beam irradiation treatment at a dose of 20 kGy, and spray-dried after being taken out to obtain the modified soy protein isolate.
[0032] The acoustic resonance frequency of the acoustic resonance treatment is 60 Hz, the amplitude is 30%, and the acceleration is 55 g.
[0033] In this embodiment, the preparation method of the modified sorbitol is as follows: by weight, 10 parts of sorbitol are taken, 80 parts of deionized water are added, and then 2 parts of polyvinyl alcohol and 1 part of glycerol are added, the temperature is raised to 60° C., stirred for 30 minutes, and then dried at 80° C. for 3 hours to obtain modified sorbitol.
[0034] Preferably, the antioxidant comprises 168, 1010, and 1076 mixed in equal proportions, and the antibacterial agent comprises chitosan, nano zinc dioxide, and curcuminol mixed in equal proportions.
[0035] Example 3 The embodiment of the present invention provides an environmentally friendly PE film packaging material for a cold preservation agent, such as Figure 1 As shown, it includes a PE film layer, and the PE film layer includes the following raw materials in parts by weight: 90 parts of PE resin, 12.5 parts of modified limonite, 10 parts of modified soy protein isolate, 5.5 parts of modified sorbitol, 2 parts of antioxidant, 3 parts of antibacterial agent, and 3 parts of zinc stearate. The production process of the environmentally friendly PE film packaging material for cold preservation includes the following steps: Weigh each raw material according to the ratio; Mixing the raw materials to obtain a premix; The obtained premix is extruded by a twin-screw extruder at 170°C and pelletized by a pelletizer to form plastic masterbatch; Adding plastic masterbatch into the hopper of the extruder, passing through the screw and die head at 185°C to the cooling roller for casting into a film, and then winding up to obtain the PE film layer; The PE film layers are laminated and cut to obtain the required packaging material.
[0036] The preparation method of the modified limonite is as follows: 22.5 parts of limonite are taken by weight, the surface is cleaned, and preliminary crushing is performed after drying; then the temperature is raised to 850°C in a muffle furnace, constant temperature roasting is performed for 2.5 hours, and the particle size is ground to 100 mesh after cooling; then 90 parts of 30vt% hydrochloric acid solution are added, the mixture is filtered after soaking for 4 hours, and the mixture is washed with deionized water for 3 times; then 90 parts of 25% sodium chloride solution and 15 parts of hydrogen peroxide are added, the mixture is stirred and mixed for 40 minutes, filtered, and dried at 70°C; then 8 parts of amino acids and 90 parts of deionized water are added, the mixture is stirred and mixed for 1.5 hours; finally, 4 parts of polyethylene glycol are added, the mixture is stirred and mixed for 50 minutes, filtered, and dried at 70°C to obtain the modified limonite.
[0037] Furthermore, the amino acids include arginine, glutamic acid, glycine, alanine, serine and other equal proportions.
[0038] Preferably, the preparation method of the modified soy protein isolate is as follows: 17.5 parts of soy protein isolate are taken by weight, dissolved in 110 parts of deionized water, and then 0.3 parts of caprolactam are added to obtain a mixed solution, the mixed solution is placed in a preset container, and subjected to an acoustic resonance treatment at 23° C. for 25 minutes, and then the mixed solution is poured into an aluminum foil bag, and vacuum-sealed with a vacuum packaging machine; the mixed solution in the aluminum foil bag is subjected to electron beam irradiation treatment at a dose of 30 kGy, and spray-dried after being taken out to obtain the modified soy protein isolate.
[0039] The acoustic resonance frequency of the acoustic resonance treatment is 65 Hz, the amplitude is 35%, and the acceleration is 60 g.
[0040] In this embodiment, the preparation method of the modified sorbitol is as follows: 12.5 parts of sorbitol are taken by weight, 90 parts of deionized water are added, and then 3.5 parts of polyvinyl alcohol and 2 parts of glycerol are added, the temperature is raised to 70°C, stirred for 40 minutes, and then dried at 90°C for 4 hours to obtain modified sorbitol.
[0041] Preferably, the antioxidant comprises 168, 1010, and 1076 mixed in equal proportions, and the antibacterial agent comprises chitosan, nano zinc dioxide, and curcuminol mixed in equal proportions.
[0042] Example 4 The embodiment of the present invention provides an environmentally friendly PE film packaging material for a cold preservation agent, such as Figure 1 As shown, it includes a PE film layer, and the PE film layer includes the following raw materials in parts by weight: 95 parts of PE resin, 14 parts of modified limonite, 11 parts of modified soy protein isolate, 7 parts of modified sorbitol, 2.5 parts of antioxidant, 4 parts of antibacterial agent, and 3.5 parts of zinc stearate. The production process of the environmentally friendly PE film packaging material for cold preservation includes the following steps: Weigh each raw material according to the ratio; Mixing the raw materials to obtain a premix; The obtained premix is extruded by a twin-screw extruder at 170°C and pelletized by a pelletizer to form plastic masterbatch; Adding the plastic masterbatch into the hopper of the extruder, passing through the screw and the die head to the cooling roller at 185°C to form a film, and then winding it up to obtain the PE film layer; The PE film layers are laminated and cut to obtain the required packaging material.
[0043] The preparation method of the modified limonite is as follows: take 25 parts of limonite by weight, clean the surface, dry and perform preliminary crushing; then place it in a muffle furnace and program the temperature to 900°C, roast it at a constant temperature for 3 hours, and grind it to a particle size of 100 mesh after cooling; then add 100 parts of 35vt% hydrochloric acid solution, soak it for 5 hours, filter it, and wash it with deionized water for 3 times; then add 100 parts of 30% sodium chloride solution and 20 parts of hydrogen peroxide, stir and mix for 50 minutes, filter it and dry it at 80°C; then add 10 parts of amino acids and 100 parts of deionized water, stir and mix it for 2 hours; finally add 5 parts of polyethylene glycol, continue to stir and mix it for 60 minutes, filter it and dry it at 80°C to obtain modified limonite.
[0044] Furthermore, the amino acids include arginine, glutamic acid, glycine, alanine, serine and other equal proportions.
[0045] Preferably, the preparation method of the modified soy protein isolate is as follows: 20 parts of soy protein isolate are taken by weight, dissolved in 120 parts of deionized water, and then 0.5 parts of caprolactam are added to obtain a mixed solution, the mixed solution is placed in a preset container, and subjected to an acoustic resonance treatment at 25° C. for 30 minutes, and then the mixed solution is poured into an aluminum foil bag, and vacuum-sealed with a vacuum packaging machine; the mixed solution in the aluminum foil bag is subjected to electron beam irradiation treatment at a dose of 40 kGy, and spray-dried after being taken out to obtain the modified soy protein isolate.
[0046] The acoustic resonance frequency of the acoustic resonance treatment is 70 Hz, the amplitude is 40%, and the acceleration is 65 g.
[0047] In this embodiment, the preparation method of the modified sorbitol is as follows: 15 parts of sorbitol are taken by weight, 100 parts of deionized water are added, and then 5 parts of polyvinyl alcohol and 3 parts of glycerol are added, the temperature is raised to 80°C, stirred for 50 minutes, and then dried at 100°C for 5 hours to obtain modified sorbitol.
[0048] Preferably, the antioxidant comprises 168, 1010, and 1076 mixed in equal proportions, and the antibacterial agent comprises chitosan, nano zinc dioxide, and curcuminol mixed in equal proportions.
[0049] Example 5 The embodiment of the present invention provides an environmentally friendly PE film packaging material for a cold preservation agent, such as Figure 1 As shown, it includes a PE film layer, and the PE film layer includes the following raw materials in parts by weight: 100 parts of PE resin, 15 parts of modified limonite, 12 parts of modified soy protein isolate, 8 parts of modified sorbitol, 3 parts of antioxidant, 5 parts of antibacterial agent, and 4 parts of zinc stearate. The production process of the environmentally friendly PE film packaging material for cold preservation includes the following steps: Weigh each raw material according to the ratio; Mixing the raw materials to obtain a premix; The obtained premix is extruded by a twin-screw extruder at 170°C and pelletized by a pelletizer to form plastic masterbatch; Adding the plastic masterbatch into the hopper of the extruder, passing through the screw and the die head to the cooling roller at 185°C to form a film, and then winding it up to obtain the PE film layer; The PE film layers are laminated and cut to obtain the required packaging material.
[0050] The preparation method of the modified limonite is as follows: take 25 parts of limonite by weight, clean the surface, dry and perform preliminary crushing; then place it in a muffle furnace and program the temperature to 900°C, roast it at a constant temperature for 3 hours, and grind it to a particle size of 100 mesh after cooling; then add 100 parts of 35vt% hydrochloric acid solution, soak it for 5 hours, filter it, and wash it with deionized water for 3 times; then add 100 parts of 30% sodium chloride solution and 20 parts of hydrogen peroxide, stir and mix for 50 minutes, filter it and dry it at 80°C; then add 10 parts of amino acids and 100 parts of deionized water, stir and mix it for 2 hours; finally add 5 parts of polyethylene glycol, continue to stir and mix it for 60 minutes, filter it and dry it at 80°C to obtain modified limonite.
[0051] Furthermore, the amino acids include arginine, glutamic acid, glycine, alanine, serine and other equal proportions.
[0052] Preferably, the preparation method of the modified soy protein isolate is as follows: 20 parts of soy protein isolate are taken by weight, dissolved in 120 parts of deionized water, and then 0.5 parts of caprolactam are added to obtain a mixed solution, the mixed solution is placed in a preset container, and subjected to an acoustic resonance treatment at 25° C. for 30 minutes, and then the mixed solution is poured into an aluminum foil bag, and vacuum-sealed with a vacuum packaging machine; the mixed solution in the aluminum foil bag is subjected to electron beam irradiation treatment at a dose of 40 kGy, and spray-dried after being taken out to obtain the modified soy protein isolate.
[0053] The acoustic resonance frequency of the acoustic resonance treatment is 70 Hz, the amplitude is 40%, and the acceleration is 65 g.
[0054] In this embodiment, the preparation method of the modified sorbitol is as follows: 15 parts of sorbitol are taken by weight, 100 parts of deionized water are added, and then 5 parts of polyvinyl alcohol and 3 parts of glycerol are added, the temperature is raised to 80°C, stirred for 50 minutes, and then dried at 100°C for 5 hours to obtain modified sorbitol.
[0055] Preferably, the antioxidant comprises 168, 1010, and 1076 mixed in equal proportions, and the antibacterial agent comprises chitosan, nano zinc dioxide, and curcuminol mixed in equal proportions.
[0056] Comparative Example 1: Compared with Example 3, the modified limonite is replaced by ordinary limonite.
[0057] Comparative Example 2: Compared with Example 3, the modified soy protein isolate was replaced by ordinary soy protein isolate.
[0058] Comparative Example 3: Compared with Example 3, the modified sorbitol was replaced by ordinary sorbitol.
[0059] Comparative Example 4: Compared with Example 3, the modified limonite was replaced by ordinary limonite, the modified soy protein isolate was replaced by ordinary soy protein isolate, and the modified sorbitol was replaced by ordinary sorbitol.
[0060] Comparative Example 5: A commercially available cold-keeping agent packaging material.
[0061] Performance Testing The packaging materials of Examples 1-5 and Comparative Examples 1-5 were subjected to performance tests of tensile strength at break and elongation at break. The test results are shown in Table 1 below: Table 1: Test results of tensile strength at break and elongation at break Test Group Tensile strength at break (MPa) Elongation at break (%) Example 1 38.5 528 Example 2 38.8 532 Example 3 38.9 535 Example 4 38.6 533 Example 5 38.5 530 Comparative Example 1 28.7 416 Comparative Example 2 30.5 425 Comparative Example 3 31.8 428 Comparative Example 4 18.5 398 Comparative Example 5 18.1 392 From the above results, it can be seen that the packaging material prepared by the present invention has excellent mechanical properties, especially by adding modified limonite, modified soy protein isolate and modified sorbitol, the three have a synergistic effect, which can greatly improve the mechanical properties of the packaging material and improve its anti-deformation performance.
[0062] It should be noted that, for the above embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described order of actions, because according to the present invention, some steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.
[0063] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field can still combine, add, delete or make other adjustments to the features in the various embodiments of the present invention according to the circumstances without conflict, without making creative work, so as to obtain different other technical solutions that do not deviate from the concept of the present invention in essence, and these technical solutions also belong to the scope of protection of the present invention.
Claims
1. An environmentally friendly PE film packaging material for cold preservation, characterized in that: The PE film layer comprises the following raw materials in parts by weight: 80-100 parts of PE resin, 10-15 parts of modified limonite, 8-12 parts of modified soy protein isolate, 3-8 parts of modified sorbitol, 1-3 parts of antioxidant, 1-5 parts of antibacterial agent and 2-4 parts of zinc stearate.
2. The environmentally friendly PE film packaging material for cold preservation according to claim 1, characterized in that: The PE film layer comprises the following raw materials in parts by weight: 85-95 parts of PE resin, 11-14 parts of modified limonite, 9-11 parts of modified soy protein isolate, 4-7 parts of modified sorbitol, 1.5-2.5 parts of antioxidant, 2-4 parts of antibacterial agent and 2.5-3.5 parts of zinc stearate.
3. The environmentally friendly PE film packaging material for cold preservation according to claim 2, characterized in that: The PE film layer comprises the following raw materials in parts by weight: 90 parts of PE resin, 12.5 parts of modified limonite, 10 parts of modified soy protein isolate, 5.5 parts of modified sorbitol, 2 parts of antioxidant, 3 parts of antibacterial agent and 3 parts of zinc stearate.
4. The environmentally friendly PE film packaging material for cold preservation according to claim 1, characterized in that: The preparation method of the modified limonite is as follows: taking 20-25 parts of limonite by weight, cleaning the surface, drying and performing preliminary crushing; then placing it in a muffle furnace and heating it to 800-900°C, constant temperature roasting for 2-3h, and grinding it to a particle size of 100-200 mesh after cooling; then adding 80-100 parts of 25-35vt% hydrochloric acid solution, soaking for 3-5h, filtering, and washing with deionized water for 3 times; then adding 80-100 parts of 20-30% sodium chloride solution and 10-20 parts of hydrogen peroxide, stirring and mixing for 30-50min, filtering and drying at 60-80°C; then adding 6-10 parts of amino acids and 80-100 parts of deionized water, stirring and mixing for 1-2h; finally adding 3-5 parts of polyethylene glycol, continuing to stir and mix for 40-60min, filtering and drying at 60-80°C to obtain the modified limonite.
5. The environmentally friendly PE film packaging material for cold preservation according to claim 4, characterized in that: The amino acids include one or more combinations of arginine, glutamic acid, glycine, alanine, and serine.
6. The environmentally friendly PE film packaging material for cold preservation according to claim 1, characterized in that: The preparation method of the modified soybean protein isolate is as follows: taking 15-20 parts of soybean protein isolate by weight, dissolving it in 100-120 parts of deionized water, then adding 0.1-0.5 parts of caprolactam to obtain a mixed solution, placing the mixed solution in a preset container, performing an acoustic resonance treatment at 20-25° C. for 20-30 minutes, then pouring the mixed solution into an aluminum foil bag, and performing a vacuum sealing treatment with a vacuum packaging machine; performing an electron beam irradiation treatment on the mixed solution in the aluminum foil bag with a dose of 20-40 kGy, and spray drying after taking it out to obtain the modified soybean protein isolate.
7. The environmentally friendly PE film packaging material for cold preservation according to claim 6, characterized in that: The acoustic resonance treatment has an acoustic resonance frequency of 60-70 Hz, an amplitude of 30-40%, and an acceleration of 55-65 g.
8. The environmentally friendly PE film packaging material for cold preservation according to claim 7, characterized in that: The preparation method of the modified sorbitol is as follows: by weight, 10-15 parts of sorbitol are taken, 80-100 parts of deionized water are added, and then 2-5 parts of polyvinyl alcohol and 1-3 parts of glycerol are added, the temperature is raised to 60-80° C., stirred for 30-50 minutes, and then dried at 80-100° C. for 3-5 hours to obtain the modified sorbitol.
9. The environmentally friendly PE film packaging material for cold preservation according to claim 7, characterized in that: The antioxidant includes one or more combinations of 168, 1010, and 1076, and the antibacterial agent includes one or more combinations of chitosan, nano zinc dioxide, and curcuminol.
10. The production process of the environmentally friendly PE film packaging material for cold preservation agents according to any one of claims 1 to 9, characterized in that: The steps include: Weigh each raw material according to the ratio; Mixing the raw materials to obtain a premix; The prepared premix is extruded by a twin-screw extruder and pelletized by a pelletizer to form plastic masterbatch; Adding plastic masterbatch into the hopper of the extruder, passing through the screw and die head to the cooling roller for casting into a film, and then winding up to obtain the PE film layer; The PE film layers are laminated and cut to obtain the required packaging material.