Sealing cover film and sealing packaging container

Abstract

The utility model belongs to the technical field of sealing packaging, and particularly relates to a sealing cover film and a sealing packaging container. The sealing cover film is sequentially provided with a polyester surface layer, a first polyurethane bonding layer, a foaming polyolefin layer, a functional bonding layer, an aluminum foil layer, a second polyurethane bonding layer and a heat sealing structure layer from outside to inside. The sealing cover film has excellent oxygen and water vapor barrier performance, and ensures that the freshness and the quality of contents are kept for a long time; good rebound resilience and space adaptability are achieved, the small deviation of the bottle opening shape and the screwing force difference can be flexibly dealt with, and ideal sealing attachment and extrusion force are ensured; the flatness and the machining stability are high, and the production efficiency and the finished product quality can be improved; and a reliable heat sealing structure is provided, so that sealing connection between the sealing cover film and the bottle opening is facilitated. A packaging container is further provided on the basis of the sealing cover film, efficient blocking protection on the content is achieved, and efficient filling of the content is facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of sealed packaging, and in particular relates to a sealed cover film and a sealed packaging container. Background Art

[0002] In today's society, the packaging of various consumer goods such as medicines and food is crucial to ensure product quality, extend shelf life and ensure consumer safety. Among them, the sealing cover film is a key structural component of the packaging system, and its performance directly affects the product's sealing effect, moisture resistance, oxidation resistance and ability to prevent microbial contamination. With consumers' increasing requirements for product quality and the complexity and changeability of logistics and storage conditions, the market has put forward higher requirements for the comprehensive performance of sealing cover films.

[0003] In the prior art, there are many types of sealing cover films used in the field of medicine and food packaging. Although traditional single-material cover films, such as PE (polyethylene), PP (polypropylene) and other film materials, have certain sealing properties, they are often unable to take into account high strength, high barrier properties, high resilience and good heat-sealing properties due to the limitations of the material itself. Especially when dealing with complex environmental conditions and long-term storage, there is a risk of sealing failure and deterioration of contents. In order to improve the overall performance of the cover film, existing technologies have attempted to adopt a multi-layer composite structure design, by combining film layers of different materials and functions to achieve better sealing effects and protective performance.

[0004] However, the existing multi-layer composite sealing cover films still have some technical defects and shortcomings. On the one hand, although some composite cover films use metal layers with excellent barrier properties such as aluminum foil, the bonding strength, durability and adaptability to environmental stress between the metal layer and the non-metal layer need to be improved, which may lead to delamination and peeling during use, affecting the sealing effect. On the other hand, the seal between the bottle mouth and the cover film depends to a large extent on the tightness of the bottle cap, and has weak adaptability to the deviation of the bottle mouth size and the dimensional influence caused by factors such as temperature fluctuations, increasing the risk of leakage or oxidation deterioration of the contents. In addition, there is room for improvement in the flatness control, heat sealing stability and fit with the bottle mouth during the processing of the existing cover film, and these factors may also affect the final sealing quality and production efficiency.

[0005] In summary, although there are many sealing cover film products in the prior art, there are still some limitations in dealing with complex environmental conditions, providing all-round protection, optimizing production efficiency and ensuring long-term sealing stability. Therefore, it is of great practical significance to develop a high-performance sealing cover film with high efficiency barrier, good rebound adaptability, excellent flatness and processing stability. Utility Model Content

[0006] In view of the deficiencies in the prior art, the utility model provides a sealing cover film and a sealed packaging container.

[0007] The purpose of the utility model is to improve the performance of the sealing cover film from the following aspects: (1) having excellent oxygen and water vapor barrier properties to ensure that the contents remain fresh and of high quality for a long time; (2) having good resilience and spatial adaptability to flexibly cope with slight deviations in the shape of the bottle mouth and differences in tightening force to ensure ideal sealing fit and extrusion force; (3) having high flatness and processing stability to help improve production efficiency and finished product quality; and (4) having a reliable heat-sealing structure to facilitate the sealing connection between the sealing cover film and the bottle mouth.

[0008] The sealing cover film provided by the utility model is provided with a polyester surface layer, a first polyurethane bonding layer, a foamed polyolefin layer, a functional bonding layer, an aluminum foil layer, a second polyurethane bonding layer and a heat-sealing structure layer in sequence from outside to inside; the polyester surface layer is located on the outside and is used for extrusion contact with the inner side of the bottle cap after packaging; the first polyurethane bonding layer is used as a bonding medium to bond the polyester surface layer to the foamed polyolefin layer; the foamed polyolefin layer is made of a foamed polyolefin material and has resilience; the functional bonding layer is used as a bonding material between the foamed polyolefin layer and the aluminum foil layer; the aluminum foil layer crosses the sealing cover film to form a barrier; the second polyurethane bonding layer is used as a bonding medium to bond the aluminum foil layer to the heat-sealing structure layer; the heat-sealing structure layer has a heat-sealing characteristic and is combined with the sealing container mouth under heat and pressure conditions.

[0009] As a further preferred embodiment, the polyester surface layer is a polyethylene terephthalate film layer.

[0010] As a further preferred embodiment, the thickness of the foamed polyolefin layer is 0.25 mm to 1.85 mm.

[0011] As a further preferred embodiment, the functional adhesive layer is made of ethylene acrylic acid copolymer or ethylene methacrylic acid copolymer.

[0012] As a further preferred embodiment, the functional adhesive layer is a polyolefin coating layer composited with a polyurethane primer layer, the polyolefin coating layer is combined with the foamed polyolefin layer, and the polyurethane primer layer is combined with the aluminum foil layer.

[0013] As a further preferred embodiment, the thickness of the aluminum foil layer is 0.06 mm to 0.28 mm.

[0014] As a further preferred embodiment, the heat-sealing structural layer comprises a PET core layer and a heat-sealing material layer which are combined together, the PET core layer is close to the second polyurethane adhesive layer, and the heat-sealing material layer is used to soften under heating conditions and combine with the bottle mouth.

[0015] As a further preferred embodiment, the surface of the PET core layer is corona treated to enhance the bonding force with the second polyurethane adhesive layer.

[0016] The utility model further provides a sealed packaging container, comprising a container body for storing contents and a cover body covering the opening of the container body, wherein the sealing cover film for closing the opening is arranged between the opening of the container body and the cover body.

[0017] As a further preferred embodiment, the sealed packaging container is a packaging bottle, comprising a bottle body and a bottle cap covering the bottle mouth of the bottle body, the bottle mouth and the bottle cap are threadedly connected, and a sealing cover film is arranged at the opening of the bottle mouth to seal the opening of the bottle mouth after the bottle body is filled with contents.

[0018] Beneficial Effects

[0019] The sealing cover film provided by the utility model combines the deformation adaptability and high resilience characteristics of the foamed polyolefin layer with the heat-sealing fixing effect of the heat-sealing structural layer, which can effectively improve the sealing performance, greatly reduce the risk of leakage, and ensure the safety and quality of medicines, foods and other contents during storage and transportation.

[0020] The sealing cover film provided by the utility model combines the high flatness and stability of the aluminum foil layer with the mechanical support and tolerance of the PET core layer, significantly improves the flatness and processing characteristics of the sealing cover film, and enhances production efficiency and product quality.

[0021] The sealing cover film provided by the utility model combines the high barrier performance of the aluminum foil layer and the auxiliary barrier effect of the functional adhesive layer, significantly improving the barrier effect against oxygen and water vapor, effectively protecting contents such as medicines and foods from the influence of the external environment, and ensuring that they maintain high quality for a long time.

[0022] The packaging container provided by the utility model is based on a high-performance sealing cover film, which realizes efficient barrier protection for the contents, ensures the safety and quality of the contents such as medicines and foods during storage and transportation, and also facilitates the efficient filling and production of the contents. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structure of the sealing cover film.

[0024] Figure 2 This is a schematic diagram of the packaging structure.

[0025] In the figure: 1, polyester surface layer; 2, first polyurethane adhesive layer; 3, foamed polyolefin layer; 4, functional adhesive layer; 5, aluminum foil layer; 6, second polyurethane adhesive layer; 7, heat-sealing structural layer. DETAILED DESCRIPTION

[0026] Example 1

[0027] The sealing cover film of this embodiment is as follows Figure 1 As shown, the following are arranged from outside to inside: polyester surface layer 1, first polyurethane adhesive layer 2, foamed polyolefin layer 3, functional adhesive layer 4, aluminum foil layer 5, second polyurethane adhesive layer 6, heat-sealing structure layer 7. The inner side of the sealing cover film refers to the side in contact with the sealed contents such as medicines and foods, and the outer side of the sealing cover film refers to the side away from the sealed contents such as medicines and foods.

[0028] Polyester surface 1

[0029] The polyester surface layer 1 is located at the outermost side and is in contact with the inner side of the bottle cap after packaging. The polyester surface layer 1 is made of polyester material, preferably polyethylene terephthalate (PET). PET polyester material has excellent dimensional stability, can withstand extrusion well, and is easy to maintain structural integrity during processing, which is convenient for production and processing.

[0030] First polyurethane adhesive layer 2

[0031] The first polyurethane adhesive layer 2 serves as an adhesive medium to bond the polyester surface layer 1 to the adjacent foamed polyolefin layer 3. The polyurethane adhesive layer is formed by curing and cross-linking the polyurethane adhesive, which has wide adhesion, good mechanical properties, excellent environmental stability and high safety.

[0032] Foamed polyolefin layer 3

[0033] The foamed polyolefin layer 3 is made of foamed polyolefin material and is a foamed film layer containing a microporous structure inside, which gives the sealing cover film excellent resilience and spatial adaptability.

[0034] The uniformly distributed microporous structure inside the foamed polyolefin layer 3 gives the material excellent deformation and cushioning properties, allowing the sealing cover film to flexibly adjust the deformation amount when responding to different tightening forces, ensuring that it always maintains an ideal fit and extrusion force with the bottle mouth and maintains good sealing performance. The foamed polyolefin layer 3 effectively absorbs and disperses stress through the deformation of its own microporous structure, avoiding the problem of sealing failure caused by excessive extrusion or insufficient contact.

[0035] The foamed polyolefin layer 3 also has a high resilience property. In the face of slight deformation of the bottle mouth or bottle cap caused by vibration, temperature change and other factors during transportation and storage, the foamed polyolefin layer 3 enables the sealing cover film to rebound quickly and always maintain close contact with the end face of the bottle mouth. This high resilience property ensures that even in long-term use or complex environments, the sealing cover film can continue to provide a stable sealing effect, effectively preventing the contents from contacting the external environment, thereby ensuring the quality of the contents such as medicines and foods for a long time.

[0036] Functional adhesive layer 4

[0037] The functional adhesive layer 4 not only serves as an adhesive material between the foamed polyolefin layer 3 and the aluminum foil layer 5, but also has certain water and gas barrier functions.

[0038] The functional adhesive layer 4 can be made of materials such as ethylene acrylic acid copolymer, ethylene methacrylic acid copolymer, etc., and firmly bonds the foamed polyolefin layer 3 and the aluminum foil layer 5 to form an integral composite barrier structure.

[0039] In addition, the functional adhesive layer 4 can also adopt the structural form of a polyolefin coating layer plus a polyurethane primer layer. The polyolefin coating layer is combined on the foamed polyolefin layer 3, and then the polyurethane primer is coated on the polyolefin coating layer for combining with the aluminum foil layer 5.

[0040] Aluminum foil layer 5

[0041] As an important component of the sealing cover film, the aluminum foil layer 5 has extremely high isolation performance against oxygen and water vapor, forming a reliable barrier in the sealing cover film, significantly reducing the invasion of external oxygen and moisture substances into canned contents such as medicines and foods, and effectively inhibiting adverse effects such as oxidation reactions, microbial growth and moisture migration, thereby delaying the deterioration of the contents and ensuring long-term freshness and original quality.

[0042] In addition, the physical properties of the aluminum foil layer 5 also bring many benefits to improving the performance and processing of the sealing cover film. The aluminum foil layer 5 has the characteristics of high hardness and no toughness, which gives the sealing cover film extremely high flatness and stability. During the processing, the sealing cover film is easier to maintain a stable shape and ensure the accuracy of the processing size. Especially after the cover film is stamped and formed, the stiffness of the aluminum foil layer 5 helps to avoid unnecessary curling of the cover film, reduce the scrap rate in the production process, and improve the stability of the finished product quality. In addition, this high flatness characteristic is also conducive to the close fit between the sealing cover film and the bottle mouth, preventing leakage caused by the distortion of the sealing cover film when the bottle cap is twisted.

[0043] Second polyurethane adhesive layer 6

[0044] The second polyurethane adhesive layer 6 is formed by curing and cross-linking polyurethane adhesive, similar to the first polyurethane adhesive layer 2. The second polyurethane adhesive layer 6 is used as an adhesive between the aluminum foil layer 5 and the heat-sealing structure layer 7 to ensure a stable and reliable bonding effect between the aluminum foil layer 5 and the heat-sealing structure layer 7.

[0045] Heat seal structure layer 7

[0046] The heat-sealing structural layer 7 is a structure on the sealing cover film that is connected to the bottle mouth, and is used to firmly attach the sealing cover film to the bottle mouth, seal the packaging bottle, and prevent the sealing cover film from shifting or peeling off during storage and transportation. Specifically, the heat-sealing structural layer 7 has a heat-sealing property, and the material can be softened and adhesive by heating (such as using ultrasonic heat sealing equipment), and the sealing cover film is firmly bonded to the bottle mouth under the action of an external extrusion force.

[0047] The heat-sealing structural layer 7 comprises a PET core layer and a heat-sealing material layer which are combined together, wherein the PET core layer is close to the second polyurethane adhesive layer 6, and the heat-sealing material layer is used to soften under heating conditions and combine with the bottle mouth.

[0048] The PET core layer is made of polyethylene terephthalate, preferably colorless and transparent polyethylene terephthalate. PET material has excellent mechanical properties, including high strength, high toughness, good impact resistance and dimensional stability. The entire heat-sealing structure layer 7 provides the necessary mechanical support. During the heat-sealing process and subsequent use, the film layer can share the mechanical effects of external stretching, twisting, etc. to a certain extent, and maintain the stability of the structure and shape. PET material has excellent friction resistance and chemical stability. It is not easy to deform or swell when in contact with medicines, foods, and water-containing and oil-containing articles, ensuring that the cover film is not affected by the contents during use.

[0049] In order to strengthen the bonding force with the second polyurethane adhesive layer 6, the surface of the PET core layer is subjected to corona treatment. Corona treatment is a physical modification method that generates instantaneous high-voltage electric sparks on the surface of the film, causing the surface molecular chains to break and rearrange, forming a large number of free radicals and polar groups. This treatment process greatly improves the surface energy and wettability of the surface layer, making it easy to form a strong interface adhesion with the second polyurethane adhesive layer 6, ensuring reliable lamination between the layers.

[0050] The entire sealing cover film is arranged in the order of polyester surface layer 1, first polyurethane adhesive layer 2, foamed polyolefin layer 3, functional adhesive layer 4, aluminum foil layer 5, second polyurethane adhesive layer 6, and heat-sealing structure layer 7, which can give full play to the advantages of each layer of materials, achieve compatibility and complementarity of multiple functions such as mechanical protection, stress dispersion, high-efficiency barrier, and heat-sealing stability, and construct a high-performance sealing cover film that can effectively protect the quality of contents such as medicines and foods and adapt to complex application environments. Specifically, the polyester surface layer 1, as the outermost layer, can effectively resist external mechanical impact and friction, and protect the internal structure from damage; the first polyurethane adhesive layer 2 firmly bonds the polyester surface layer 1 and the foamed polyolefin layer 3; the foamed polyolefin layer 3 is close to the middle, providing excellent rebound effect and spatial adaptability for both sides; the functional adhesive layer 4 tightly combines the foamed polyolefin layer 3 and the aluminum foil layer 5; the aluminum foil layer 5, as an important barrier layer, is close to the middle and biased to the inside, has high isolation performance against oxygen and water vapor, and forms an effective protective barrier for the contents. Its high hardness and toughness also give the sealing cover film high flatness and stability, which is easy to process; the second polyurethane adhesive layer 6 firmly connects the aluminum foil layer 5 and the heat-sealing structure layer 7; the heat-sealing structure layer 7 is located on the innermost side, and forms a strong bonding effect with the bottle mouth under the action of heat and pressure.

[0051] A method for manufacturing a sealing lid film and a packaging container is exemplarily introduced below.

[0052] Step (1): using dry laminating equipment to bond the polyester surface layer 1 and the foamed polyolefin layer 3, the adhesive is polyurethane, and after bonding, a first polyurethane bonding layer 2 is formed. The processing speed is controlled at 100±20m / min, and the drying temperature is 50-110°C.

[0053] Step (2): using dry composite equipment to complete the bonding of the aluminum foil layer 5 and the heat-sealing structure layer 7. The adhesive is polyurethane. After bonding, a second polyurethane bonding layer 6 is formed. The processing speed is controlled at 100±20 m / min and the drying temperature is 50-110°C.

[0054] Step (3): using an extrusion composite device, the composite sheets obtained in step (1) and step (2) are bonded together, specifically, a functional bonding layer 4 is formed by extrusion to bond the foamed polyolefin layer 3 and the aluminum foil layer 5 together. The thickness of the functional bonding layer 4 is preferably controlled to be 8-35 μm, and the processing speed is controlled to be 90±20 m / min. After the composite is completed, a sealing cover film is obtained.

[0055] Step (4): using a die-cutting device, cut out independent disc-shaped sealing cover films from the sealing cover film obtained in step (3).

[0056] Step (5): Using heat sealing welding equipment, weld one side of the heat sealing structure layer 7 of the disc cover film to the mouth of a container such as a bottle mouth.

[0057] Example 2

[0058] This embodiment provides an improved sealed packaging container based on the sealing cover film of Example 1. The sealed packaging container can be a packaging bottle, a packaging bag, a packaging box, a packaging case, a packaging can, a packaging hose, etc. The sealed packaging container includes a container body for storing contents and a cover body covering the opening of the container body, and a sealing cover film for sealing the opening is arranged between the opening of the container body and the cover body, and the sealing cover film is the sealing cover film described in Example 1. The contents to be sealed and preserved are filled into the container body, and then the sealing cover film is sealed to the opening of the container body by using a heat sealing device and the cover body is covered, or the cover body pre-set with the sealing cover film is covered and then the sealing cover film is combined with the opening by using a heating device such as ultrasonic wave.

[0059] Take packaging bottles as an example. Figure 2 As shown, it comprises a bottle body and a bottle cap covering the bottle mouth of the bottle body, the bottle mouth and the bottle cap are threadedly connected, and a sealing cover film is arranged at the opening of the bottle mouth to seal the opening of the bottle mouth after the bottle body is filled with contents. In actual use, a more convenient solution is to place the sealing cover film in the bottle cap in advance, tighten the bottle cap on the bottle mouth after the bottle body is filled with contents, and then heat the sealing cover film through an ultrasonic heating device to combine it with the bottle mouth opening to seal the opening.

[0060] The above implementation modes are exemplary, and their purpose is to illustrate the technical concept and features of the utility model so that people familiar with the technology in this field can understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A sealing cover film, characterized in that: The sealing cover film is provided with a polyester surface layer (1), a first polyurethane adhesive layer (2), a foamed polyolefin layer (3), a functional adhesive layer (4), an aluminum foil layer (5), a second polyurethane adhesive layer (6), and a heat-sealing structural layer (7) in order from the outside to the inside; the polyester surface layer (1) is located on the outside and is used to be in extrusion contact with the inner side of the bottle cap after packaging; the first polyurethane adhesive layer (2) serves as an adhesive medium to bond the polyester surface layer (1) to the foamed polyolefin layer (3); the foamed polyolefin layer (3) is made of a foamed polyolefin material and has resilience; the functional adhesive layer (4) serves as an adhesive material between the foamed polyolefin layer (3) and the aluminum foil layer (5); the aluminum foil layer (5) crosses the sealing cover film to form a barrier; the second polyurethane adhesive layer (6) serves as an adhesive medium to bond the aluminum foil layer (5) to the heat-sealing structural layer (7); the heat-sealing structural layer (7) has a heat-sealing property and is combined with the sealing container mouth under heat and pressure conditions.

2. The sealing cover film according to claim 1, characterized in that: The polyester surface layer (1) is a polyethylene terephthalate film layer.

3. The sealing cover film according to claim 1, characterized in that: The thickness of the foamed polyolefin layer (3) is 0.25 mm to 1.85 mm.

4. The sealing cover film according to claim 1, characterized in that: The functional adhesive layer (4) is made of ethylene acrylic acid copolymer or ethylene methacrylic acid copolymer.

5. The sealing cover film according to claim 1, characterized in that: The functional bonding layer (4) is a polyolefin coating layer composited with a polyurethane primer layer, the polyolefin coating layer is bonded to the foamed polyolefin layer (3), and the polyurethane primer layer is bonded to the aluminum foil layer (5).

6. The sealing cover film according to claim 1, characterized in that: The thickness of the aluminum foil layer (5) is 0.06 mm to 0.28 mm.

7. The sealing cover film according to claim 1, characterized in that: The heat-sealing structural layer (7) comprises a PET core layer and a heat-sealing material layer that are combined together, the PET core layer being close to the second polyurethane adhesive layer (6), and the heat-sealing material layer being used to soften under heating conditions and to be combined with the bottle mouth.

8. The sealing cover film according to claim 7, characterized in that: The surface of the PET core layer is subjected to corona treatment to enhance the bonding force with the second polyurethane adhesive layer (6).

9. A sealed packaging container, characterized in that: The container comprises a container body for storing contents and a cover body covering an opening of the container body, a sealing cover film for closing the opening is arranged between the opening of the container body and the cover body, and the sealing cover film is the sealing cover film according to any one of claims 1 to 8.

10. The sealed packaging container according to claim 9, characterized in that: The sealed packaging container is a packaging bottle, comprising a bottle body and a bottle cap covering the bottle mouth of the bottle body, the bottle mouth and the bottle cap are threadedly connected, and a sealing cover film is arranged at the opening of the bottle mouth to seal the opening of the bottle mouth after the bottle body is filled with contents.

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