A recyclable, high-barrier, UV-resistant composite film and food packaging bags

Abstract

The disclosed recyclable high-barrier UV-resistant composite film comprises an MDOPE-EVOH film layer, an adhesive layer, and a UV-resistant modified PE film layer. The MDOPE-EVOH film layer and the UV-resistant modified PE film layer are bonded together by the adhesive layer. An INK ink layer is printed on the inner surface of the MDOPE-EVOH film layer. The MDOPE-EVOH film layer is a co-extruded film layer obtained by melt co-extrusion blown film and longitudinal stretching, wherein the EVOH layer thickness accounts for 10%-20%. The adhesive layer is an ADH adhesive. The UV-resistant modified PE film layer is obtained by adding hindered amine light stabilizer to PE particles and then melt extruding blown film, with the hindered amine light stabilizer addition ratio being 1wt%-2wt%. The thickness of the MDOPE-EVOH film layer is 20-30 μm, the thickness of the INK ink layer is 1-2 μm, the thickness of the adhesive layer is 2-3 μm, and the thickness of the UV-resistant modified PE film layer is 80 μm or more. A food packaging bag made by cutting and heat-sealing the above composite film is also disclosed. When used as a food packaging bag material, this composite film not only meets the requirements for recyclability, but also has excellent barrier properties and UV protection, which can extend the shelf life of food contents.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of composite film for food packaging, and particularly relates to a recyclable high-barrier ultraviolet-resistant composite film and a food packaging bag made of the same. BACKGROUND

[0002] Currently, some products on the market, such as edible oil, milk, and beverage, are packaged in transparent bags. In addition to the high water barrier and oxygen barrier to ensure the quality of the products, these products also need a certain ultraviolet resistance to avoid the deterioration of the products caused by high peroxide value due to ultraviolet light.

[0003] The conventional transparent bag packaging usually uses PET (polyethylene terephthalate), NY (nylon), PE (polyethylene), and other materials to form a composite film to meet the above requirements. However, this type of composite film packaging bag does not meet the recyclable standard and cannot meet the current environmental protection policy requirements.

[0004] Therefore, the present application develops a recyclable composite film product that meets the recyclable standard to meet the needs of the food packaging bag. SUMMARY

[0005] In view of the content described in the background, the present application provides a recyclable high-barrier ultraviolet-resistant composite film, which is used as a food packaging bag material and meets the recyclable requirements while having high barrier properties and ultraviolet resistance.

[0006] The disclosed recyclable high-barrier ultraviolet-resistant composite film includes an MDOPE-EVOH film layer, an adhesive layer, and an ultraviolet-resistant modified PE film layer. The MDOPE-EVOH film layer and the ultraviolet-resistant modified PE film layer are connected by the adhesive layer.

[0007] Further, the recyclable high-barrier ultraviolet-resistant composite film further includes an INK ink layer, which is printed on the inner surface of the MDOPE-EVOH film layer by gravure or flexographic printing.

[0008] Preferably, the MDOPE-EVOH film layer is a co-extruded film layer prepared by melt co-extrusion and longitudinal stretching. The thickness ratio of EVOH in the co-extruded film layer is 10%-20%. Such MDOPE-EVOH film layer has high water barrier and oxygen barrier properties, and its oxygen barrier performance is better than that of a single conventional MDOPE high-barrier film. In addition to providing barrier properties, the MDOPE-EVOH film layer can also be used as a printing layer material, which simplifies the structure of the composite film and reduces the cost.

[0009] Preferably, the adhesive layer is an ADH adhesive, specifically ADH50.50, which has strong adhesion and meets the temperature resistance requirements of food packaging as a soft packaging adhesive.

[0010] Preferably, the UV-resistant modified PE film layer is prepared by melt extrusion blown film after adding hindered amine light stabilizer to PE particles. The addition ratio of the hindered amine light stabilizer is 1wt%-2wt%, and the specific type of the hindered amine light stabilizer is SABO40, which is a food-grade UV-resistant additive. It has a protective effect on contents sensitive to ultraviolet light, such as some edible oils, to prevent the PA (peroxide value) value from becoming too high due to ultraviolet light exposure, thus preventing deterioration. Therefore, when the UV-resistant modified PE film layer is used as the inner layer of the composite film, it can play the role of blocking ultraviolet light and heat sealing.

[0011] Preferably, the thickness of the MDOPE-EVOH film layer is 20-30 μm, the thickness of the INK ink layer is 1-2 μm, the thickness of the adhesive layer is 2-3 μm, and the thickness of the UV-resistant modified PE film layer is 80 μm or more.

[0012] By controlling the thickness of each film layer, the EVOH and ink / adhesive content in the packaging is less than 10%, with the remainder being polyethylene materials. According to the "Circular Economy Design Guidelines" of the European Circular Economy Organization for Flexible Packaging (CEFLEX), the single material of flexible packaging mainly refers to a single polyolefin material, a single polypropylene (PP) material, or a single polyethylene (PE) material with a weight ratio exceeding 90%. Based on this requirement, the composite film described in this application belongs to single-material packaging and meets the recyclability standard requirements.

[0013] A food packaging bag is disclosed, which is made by cutting and heat-sealing the aforementioned recyclable, high-barrier, and UV-resistant composite film.

[0014] Through the above technical solutions, the present invention has at least the following beneficial effects:

[0015] The recyclable, high-barrier, UV-resistant composite film described in this application, as a food packaging bag material, not only meets recyclability requirements but also possesses excellent oxygen and water barrier properties and UV protection, thus extending the shelf life of food contents. Furthermore, while possessing the aforementioned multifunctionalities, the composite film of this application has a simple structure, low manufacturing cost, and broad application prospects. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a recyclable, high-barrier, UV-resistant composite membrane described in the embodiments of this application. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0018] Example 1

[0019] This embodiment provides a recyclable, high-barrier, UV-resistant composite membrane, comprising an MDOPE-EVOH film layer, an adhesive layer, and a UV-resistant modified PE film layer. The MDOPE-EVOH film layer and the UV-resistant modified PE film layer are compositely connected by the adhesive layer. Specifically, it also includes an INK ink layer, which is gravure-printed on the inner surface of the MDOPE-EVOH film layer.

[0020] The MDOPE-EVOH film is a co-extruded film obtained by melt co-extrusion blown film followed by longitudinal stretching, with EVOH accounting for 15% of the film thickness. This MDOPE-EVOH film has both high water and oxygen barrier properties, and its oxygen barrier performance is better than that of conventional MDOPE high barrier films. In addition to providing barrier properties, the MDOPE-EVOH film can also be used as a printing layer material. The multifunctional film simplifies the structure of the composite film and reduces costs.

[0021] The adhesive layer is an ADH adhesive, specifically model ADH50.50. As a flexible packaging adhesive, it has strong adhesion and its temperature resistance meets the requirements for food packaging.

[0022] The UV-resistant modified PE film is prepared by melt extrusion blown film after adding hindered amine light stabilizer to PE particles. The hindered amine light stabilizer is added at a ratio of 1.5 wt%, and the specific type of hindered amine light stabilizer is SABO40. It is a food-grade UV-resistant additive that protects contents sensitive to ultraviolet light, such as some edible oils, from UV exposure causing their PA (peroxide value) value to rise and thus leading to deterioration. Therefore, when the UV-resistant modified PE film is used as the inner layer of the composite film, it can block ultraviolet light and heat seal.

[0023] In the above-mentioned recyclable high-barrier UV-resistant composite film: the thickness of the MDOPE-EVOH film layer is 25um, the thickness of the INK ink layer is 1.5um, the thickness of the adhesive layer is 2.5um, and the thickness of the UV-resistant modified PE film layer is 110um.

[0024] By controlling the thickness of each film layer, the EVOH and ink / adhesive content in the packaging is less than 10%, with the remainder being polyethylene materials. According to the "Circular Economy Design Guidelines" of the European Circular Economy Organization for Flexible Packaging (CEFLEX), the single material of flexible packaging mainly refers to a single polyolefin material, a single polypropylene (PP) material, or a single polyethylene (PE) material with a weight ratio exceeding 90%. Based on this requirement, the composite film described in this application belongs to single-material packaging and meets the recyclability standard requirements.

[0025] The aforementioned recyclable, high-barrier, UV-resistant composite film can be cut and heat-sealed to create food packaging bags for edible oils, milk, beverages, etc., meeting recyclability requirements while possessing high barrier properties and UV protection.

[0026] Example 2

[0027] This embodiment provides a recyclable, high-barrier, UV-resistant composite membrane, comprising an MDOPE-EVOH film layer, an adhesive layer, and a UV-resistant modified PE film layer. The MDOPE-EVOH film layer and the UV-resistant modified PE film layer are compositely connected by the adhesive layer. Specifically, it also includes an INK ink layer, which is flexographically printed on the inner surface of the MDOPE-EVOH film layer.

[0028] The MDOPE-EVOH film is a co-extruded film obtained by melt co-extrusion blown film followed by longitudinal stretching. The EVOH layer accounts for 10% of the thickness of the co-extruded film. This MDOPE-EVOH film has both high water barrier and high oxygen barrier properties. Compared with conventional MDOPE high barrier films, its oxygen barrier performance is better. In addition to providing barrier properties, the MDOPE-EVOH film can also be used as a printing layer material. The multifunctional film simplifies the structure of the composite film and reduces costs.

[0029] The adhesive layer is an ADH adhesive, specifically model ADH50.50. As a flexible packaging adhesive, it has strong adhesion and its temperature resistance meets the requirements for food packaging.

[0030] The UV-resistant modified PE film is prepared by melt extrusion blown film after adding hindered amine light stabilizer to PE particles. The hindered amine light stabilizer is added at a ratio of 2 wt%, and the specific type of hindered amine light stabilizer is SABO40. It is a food-grade UV-resistant additive that protects contents sensitive to UV light, such as some edible oils, from UV exposure causing their PA (peroxide value) value to rise and thus leading to deterioration. Therefore, when the UV-resistant modified PE film is used as the inner layer of the composite film, it can block UV light and heat seal.

[0031] In the above-mentioned recyclable high-barrier UV-resistant composite film: the thickness of the MDOPE-EVOH film layer is 30µm, the thickness of the INK ink layer is 1µm, the thickness of the adhesive layer is 2µm, and the thickness of the UV-resistant modified PE film layer is 80µm.

[0032] By controlling the thickness of each film layer, the EVOH and ink / adhesive content in the packaging is less than 10%, with the remainder being polyethylene materials. According to the "Circular Economy Design Guidelines" of the European Circular Economy Organization for Flexible Packaging (CEFLEX), the single material of flexible packaging mainly refers to a single polyolefin material, a single polypropylene (PP) material, or a single polyethylene (PE) material with a weight ratio exceeding 90%. Based on this requirement, the composite film described in this application belongs to single-material packaging and meets the recyclability standard requirements.

[0033] The aforementioned recyclable, high-barrier, UV-resistant composite film can be cut and heat-sealed to create food packaging bags for edible oils, milk, beverages, etc., meeting recyclability requirements while possessing high barrier properties and UV protection.

[0034] Example 3

[0035] This embodiment provides a recyclable, high-barrier, UV-resistant composite membrane, comprising an MDOPE-EVOH film layer, an adhesive layer, and a UV-resistant modified PE film layer. The MDOPE-EVOH film layer and the UV-resistant modified PE film layer are compositely connected by the adhesive layer. Specifically, it also includes an INK ink layer, which is gravure-printed on the inner surface of the MDOPE-EVOH film layer.

[0036] The MDOPE-EVOH film is a co-extruded film obtained by melt co-extrusion blown film followed by longitudinal stretching. The EVOH layer accounts for 20% of the thickness of the co-extruded film. This MDOPE-EVOH film has both high water barrier and high oxygen barrier properties. Compared with conventional MDOPE high barrier films, its oxygen barrier performance is better. In addition to providing barrier properties, the MDOPE-EVOH film can also be used as a printing layer material. The multifunctional film simplifies the structure of the composite film and reduces costs.

[0037] The adhesive layer is an ADH adhesive, specifically model ADH50.50. As a flexible packaging adhesive, it has strong adhesion and its temperature resistance meets the requirements for food packaging.

[0038] The UV-resistant modified PE film is prepared by melt extrusion blown film after adding hindered amine light stabilizer to PE particles. The hindered amine light stabilizer is added at a ratio of 1 wt%, and the specific type of hindered amine light stabilizer is SABO40. It is a food-grade UV-resistant additive that protects contents sensitive to ultraviolet light, such as some edible oils, from UV exposure causing their PA (peroxide value) value to rise and thus leading to deterioration. Therefore, when the UV-resistant modified PE film is used as the inner layer of the composite film, it can block ultraviolet light and heat seal.

[0039] In the above-mentioned recyclable high-barrier UV-resistant composite film: the thickness of the MDOPE-EVOH film layer is 20µm, the thickness of the INK ink layer is 2µm, the thickness of the adhesive layer is 3µm, and the thickness of the UV-resistant modified PE film layer is 150µm.

[0040] By controlling the thickness of each film layer, the EVOH and ink / adhesive content in the packaging is less than 10%, with the remainder being polyethylene materials. According to the "Circular Economy Design Guidelines" of the European Circular Economy Organization for Flexible Packaging (CEFLEX), the single material of flexible packaging mainly refers to a single polyolefin material, a single polypropylene (PP) material, or a single polyethylene (PE) material with a weight ratio exceeding 90%. Based on this requirement, the composite film described in this application belongs to single-material packaging and meets the recyclability standard requirements.

[0041] The aforementioned recyclable, high-barrier, UV-resistant composite film can be cut and heat-sealed to create food packaging bags for edible oils, milk, beverages, etc., meeting recyclability requirements while possessing high barrier properties and UV protection.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Based on the present invention, and through the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0043] The oxygen barrier and water barrier properties of the products in the above three embodiments were tested according to ASTM D 3985-17 and ASTM F 1249-13, respectively. The results are shown in Table 1 below. The results are the average values ​​of multiple samples.

[0044] Table 1:

[0045]

[0046]

[0047] The UV resistance of the products in the three embodiments described above was measured using the following method and compared with that of 12µm thick PET and 15µm thick NY (nylon). The results are shown in Table 2 below:

[0048] Cut a suitable test sample from the composite film product, ensuring the sample is flat, wrinkle-free, and free of obvious defects, and that its area completely covers the instrument's test window. Turn on the UV-Vis spectrophotometer and allow it to warm up for a period of time to reach a stable working state. After calibration using a blank reference, place the prepared sample in the instrument's test optical path, ensuring that the light passes perpendicularly through the sample. Set an appropriate wavelength scanning range and interval in the UV band. This test starts at 280nm, with 10nm intervals, scanning up to 400nm, and then starts the measurement. The instrument will record the light intensity transmitted through the sample at each wavelength and compare it with the light intensity at the blank reference. Calculate the UV transmittance using the formula: Transmittance (T) = (Light intensity transmitted through the sample / Light intensity at the blank reference) × 100%.

[0049] Table 2:

[0050]

[0051]

[0052] As shown in Tables 1 and 2, the products of each embodiment, while meeting the requirements for recyclability, also possess excellent oxygen and water barrier properties and UV protection, which can extend the shelf life of food contents. In addition, the composite membrane products of each embodiment, while possessing the above-mentioned multifunctionality, have a simple structure, low manufacturing cost, and broad application prospects.

Claims

1. A recyclable high barrier ultraviolet resistant composite film, characterized in that: The MDOPE-EVOH film layer, the adhesive layer, the anti-ultraviolet modified PE film layer and the INK ink layer are composed, the MDOPE-EVOH film layer and the anti-ultraviolet modified PE film layer are connected by the adhesive layer, and the INK ink layer is printed on the inner surface of the MDOPE-EVOH film layer. The MDOPE-EVOH film layer is a co-extruded film layer prepared by melt co-extrusion and longitudinal stretching, and the thickness ratio of EVOH in the co-extruded film layer is 10-20%. The anti-ultraviolet modified PE film layer is prepared by melt extrusion and blowing after adding a hindered amine light stabilizer into PE particles, and the addition ratio of the hindered amine light stabilizer is 1wt%-2wt%. The thickness of the MDOPE-EVOH film layer is 20-30um, the thickness of the INK ink layer is 1-2um, the thickness of the adhesive layer is 2-3um, and the thickness of the anti-ultraviolet modified PE film layer is more than 80um.

2. The recyclable high barrier ultraviolet resistant composite film according to claim 1, characterized in that: The adhesive layer is an ADH adhesive.

3. A food packaging bag characterized by: It is cut and hot sealed by the recyclable high-barrier anti-ultraviolet composite film of claim 1 or 2.

Images