Sealing structure for packaging box, production process for sealing structure, and packaging box

Abstract

A sealing structure for a packaging box, a production process for a sealing structure, and a packaging box. The sealing structure comprises a base (2), a sealing cover (3) and a pull tab (4), wherein an opening is formed in the packaging box, the base (2) is arranged on the inner side of the opening, and a through hole is formed in the base (2); the sealing cover (3) has a closure portion, and when the sealing cover (3) is closed, the closure portion passes through the opening and is embedded into the through hole such that the closure portion tightly fits with the base (2) so as to close the opening; and the pull tab (4) is arranged on the outer side of the packaging box, and is fixedly connected to the sealing cover (3) and is configured to drive the sealing cover (3) to open or close the opening. The packaging box can be opened repeatedly, which reduces the production and manufacturing cost and is more environmentally friendly, and achieves better closure and convenience. In addition, the upper end of the base (2) wraps around the entire outer edge of the opening, thus improving the sealing performance of the opening of the packaging box and preventing leakage caused by liquid contents seeping into the paper base.

Description

Sealing structure of packaging box, production process of sealing structure and packaging box Technical Field

[0001] The present application relates to the technical field of product packaging, and in particular to a sealing structure of a packaging box, a production process of the sealing structure, and a packaging box. Background Art

[0002] Non-carbonated liquid foods, such as drinking water, milk, and yogurt, as well as semi-liquid foods like juice, are widely packaged and sold in three-dimensional packaging boxes. These boxes are typically made from paper-based composite packaging materials, which consist of a multi-layered structure consisting of a paper base, a barrier layer (such as aluminum foil), a waterproof layer, and an innermost layer. Once the composite packaging material is manufactured, it is shipped from the packaging material manufacturer to a food filling company. There, the composite packaging material is loaded onto a filling machine and undergoes multiple processes, including filling, sealing, and shaping, to create a liquid food packaging box.

[0003] Liquid food packaging boxes typically use disposable seals or plastic packaging lids. Plastic packaging lids are not only expensive to produce, but also generate large amounts of non-biodegradable plastic waste, placing a heavy burden on the environment. Disposable seals used in liquid food packaging boxes, such as pull-tabs, offer advantages such as ease of opening and low cost, making them ideal for liquid food packaging, especially for small-volume liquid food packaging. However, on the one hand, pull-tabs on liquid food packaging boxes in the past could only be opened once and could not be reclosed after opening, making them unreusable. This made liquid food packaging boxes with pull-tabs difficult to open immediately after drinking and inconvenient to carry. On the other hand, pull-tabs in existing technologies are difficult to open and can easily tear due to improper force during opening, causing the liquid contents to spill. The sealing and sanitation of the opening of liquid food packaging boxes are also poor, especially for packaging boxes that have been stored for a long time. The opening is prone to dust accumulation and bacterial contamination. If the packaging material at the opening is penetrated by the liquid contents during pouring, the opening can soften and deform, causing liquid leakage. Summary of the Invention

[0004] In view of the above problems, the present application is proposed to provide a sealing structure of a packaging box, a production process of the sealing structure and a packaging box, so as to achieve the technical effects of repeatedly opening or closing the opening of the packaging box, improving the sealing of the opening of the packaging box, and preventing the penetration of liquid contents.

[0005] According to the first aspect of the present application, a sealing structure of a packaging box is provided, the sealing structure comprising: a base, a sealing cover and a pull tab,

[0006] The packaging box is provided with an opening, the base is provided on the inner side of the packaging box at the opening position, and the base is provided with a through hole;

[0007] The sealing cover has a sealing portion. When the sealing cover is closed, the sealing portion passes through the opening and is embedded in the through hole. The sealing portion is tightly engaged with the base to close the opening.

[0008] The pull tab is arranged on the outside of the packaging box, and is fixedly connected to the sealing cover to drive the sealing cover to open or close the opening.

[0009] Optionally, when the sealing cover is closed, the outer edge of the sealing portion is tightly engaged with the inner edge of the through hole of the base to close the opening.

[0010] Optionally, a protrusion is provided on the outer edge of the closing portion, and a groove is provided on the inner edge of the through hole, and the protrusion abuts against the groove to close the opening.

[0011] Optionally, the protrusion has at least two different protrusion heights.

[0012] Optionally, the raised portion has a deep portion with a larger raised height and a shallow portion with a smaller raised height, the length ratio of the deep portion to the shallow portion is 1:(1-4), and the height ratio of the shallow portion to the deep portion is 1:(1.5-3); or the raised portion is a symmetrical structure, and the raised heights on both sides of the symmetry axis are set progressively.

[0013] Optionally, the base extends toward the outside of the packaging box along the edge of the opening to form a sealing ring, and the height of the sealing ring is not less than the height of the opening, so that the sealing ring completely covers the edge of the opening.

[0014] Optionally, the closing portion is a solid structure or a hollow structure.

[0015] Optionally, the closing portion is provided with an opening, or the closing portion is an annular structure, or the closing portion is provided with a groove, or the bottom surface of the closing portion is inclined.

[0016] Optionally, the sealing cover further includes a top portion, which is located outside the opening, and the pull tab is fixedly connected to the top portion.

[0017] Optionally, the sealing cover and the pull tab are integrally formed, or the sealing cover and the pull tab are formed separately and then fixedly connected.

[0018] Optionally, it also includes an inner membrane, which is arranged below the base. The area of ​​the inner membrane is larger than that of the base. The inner membrane is fixedly connected to the closing portion. Before the sealing cover is opened for the first time, the inner membrane completely covers the base and is fixedly connected to the inside of the packaging box; after the sealing cover is opened, the inner membrane ruptures.

[0019] Optionally, it also includes: an outer film, which is arranged on the outside of the packaging box at the opening position, and the area of ​​the outer film is smaller than the area of ​​the pull tab. Before the sealing cover is opened for the first time, the pull tab is fixedly connected to the outer film; after the sealing cover is opened, the pull tab is separated from the outer film.

[0020] According to a second aspect of the present application, a production process for a packaging box sealing structure is provided, the production process comprising:

[0021] Step a, punching holes in a composite packaging material for preparing a packaging box to form an opening;

[0022] Step b, providing a base at a position corresponding to the opening on the inner side of the packaging box, wherein the base is provided with a through hole;

[0023] Step c, providing a sealing cover, wherein the sealing cover has a sealing portion, which passes through the opening and is embedded in the through hole, and the sealing portion is tightly engaged with the base to seal the opening;

[0024] Step d: a pull tab is provided on the outside of the packaging box, wherein the pull tab is fixedly connected to the sealing cover and is used to drive the sealing cover to open or close the opening.

[0025] Optionally, the production process further comprises:

[0026] Step e: an inner membrane is provided below the base. The area of ​​the inner membrane is larger than that of the base. The inner membrane completely covers the base and is fixedly connected to the sealing portion and the inner side of the packaging box.

[0027] Optionally, the production process also includes setting an outer film, setting the outer film at the opening position on the outside of the corresponding packaging box, and the area of ​​the outer film is larger than the area of ​​the opening; or setting the outer film on the composite packaging material on the outside of the corresponding packaging box, and then punching holes in the outer film to form an opening.

[0028] According to a third aspect of the present application, a packaging box is provided, which is provided with a sealing structure as described in any one of the first aspects above, or the packaging box is provided with a sealing structure prepared according to any one of the production processes described in the second aspect above.

[0029] Optionally, the packaging box is made of a composite packaging material, which includes a base layer, a printing layer, a waterproof layer and an innermost layer.

[0030] As can be seen from the above, at least one of the technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects: a sealing structure for a packaging box is provided, comprising: a base, a sealing cover, and a pull tab. By arranging the base on the inside of the packaging box, the sealing cover passes through the opening and tightly engages with the base on the inside of the packaging box to close the opening. Arranging the base on the inside of the packaging box not only reduces the space occupied by the base on the outer surface of the packaging box, making the packaging box more simple and beautiful in appearance, and convenient for transportation and display; it also makes the closure of the opening more secure and safe, avoiding the risk of the sealing cover being accidentally opened due to external force when the base is arranged on the outside of the packaging box, and at the same time prevents dust and debris from entering through external gaps, making it cleaner. The pull tab connected to the sealing cover can not only drive the sealing cover to repeatedly open or close the opening, realizing the reusable sealing structure of the packaging box, making the packaging box more convenient to use and carry, but also can shield the opening, further ensuring a sanitary and safe environment at the opening, and improving the food safety of the packaging box.

[0031] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0033] FIG1 is a longitudinal cross-sectional view of a sealing structure in one embodiment of the present application;

[0034] Figure 2 is an enlarged view of portion A in Figure 1;

[0035] FIG3 is a longitudinal cross-sectional view of a sealing structure in another embodiment of the present application;

[0036] FIG4 is a longitudinal cross-sectional view of a sealing structure in yet another embodiment of the present application;

[0037] FIG5 is a flow chart of the production process of the sealing structure of the packaging box in this application.

[0038] In the figure: 1. composite packaging material; 2. base; 3. sealing cover; 4. pull tab; 5. inner film; 6. outer film; 7. sealing ring; 8. raised part. DETAILED DESCRIPTION

[0039] The following describes exemplary embodiments of the present application in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0040] The technical solutions provided by various embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0041] In one embodiment of the present application, a sealing structure for a packaging box is proposed. The packaging box can be made of a composite packaging material. The composite packaging material generally includes a base layer, a printed layer, a waterproof layer, and an innermost layer. The base layer of the composite packaging material is generally made of raw paper, such as white or kraft paper. The base layer provides the composite packaging material with the necessary stiffness, allowing the packaging box to maintain a stable appearance. The composite packaging material may also include a barrier layer, which plays a critical role in the shelf life of liquid foods by preventing oxygen from penetrating into the packaging container, thereby extending the shelf life of the food. Aluminum foil is typically used as the barrier layer in composite packaging materials. The waterproof layer is generally composed of a thermoplastic resin, preferably a polyolefin, including but not limited to low-density polyethylene (LDPE), metallocene polyethylene (m-PE), or a mixture of the two. Located on the outermost layer of the composite packaging material, the waterproof layer provides water and dust resistance and protects the printed layer from abrasion. The innermost layer of the composite packaging material is in direct contact with the package contents. The innermost layer is typically made of a thermoplastic resin, preferably a polyolefin such as polyethylene (PE), including but not limited to linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (ULDPE), low-density polyethylene (LDPE), metallocene polyethylene (MPE), or mixtures thereof. Adhesive layers are typically provided between the base layer and the barrier layer, and between the barrier layer and the innermost layer. These layers serve to bond the two adjacent layers and are typically made of an adhesive polymer, such as a modified polypropylene-based thermoplastic adhesive polymer. The packaging box is provided with an opening for the contents to be discharged or consumed. This opening is created by perforating the composite packaging material with a punching device. A sealing structure is positioned at the opening to facilitate repeated opening and closing.

[0042] In this embodiment, as shown in FIG1 , the sealing structure includes: a base 2, a sealing cover 3, and a pull tab 4. An opening is provided on the composite packaging material 1, and the base 2 is disposed on the inner side of the packaging box at the opening. Unless otherwise specified in this application, the outer side refers to the side facing the outside air, and the inner side refers to the side facing the package contents. The base is provided with a through hole; the sealing cover has a sealing portion. When the sealing cover is closed, the sealing portion passes through the opening and engages with the through hole, and the sealing portion tightly engages with the base to seal the opening. The base is disposed on the inner side of the packaging box, and the sealing portion of the sealing cover tightly engages with the base on the inner side of the packaging box to seal the opening. This reduces the base's footprint on the outer surface of the packaging box, not only making the packaging box more concise and beautiful, but also facilitating the stacking and display of the packaging boxes in transportation and on display racks. In addition, the base disposed on the inner side of the packaging box provides a more concealed and secure closure of the opening, reducing the risk of the sealing cover being accidentally opened by external forces when the base is exposed to the outside of the packaging box. The base also provides a dust-proof effect.

[0043] Preferably, the opening can be configured as a teardrop or circular shape, and the shape of the through hole of the base 2 and the sealing cover 3 can also be adjusted to a teardrop or circular shape accordingly. Of course, the shapes, sizes, and materials of the opening, base, and sealing cover are not limited in the embodiments of the present application. The above is only for ease of understanding and simplified description and should not be considered as limitations of the present application. After the sealing structure is opened, the sealing cover 3 can be pulled out of the base 2 fixed to the opening and / or pressed back, such as pressing the sealing cover 3 to make it embed into the base 2 to achieve sealing of the opening.

[0044] The material for preparing the base 2 and the sealing cover 3 can be one or more of plastic, paper, paper-plastic composite materials, cellulose (such as modified cellulose, natural cellulose, artificial cellulose, dry-molded fiber and other cellulose products or cellulose materials), degradable biomaterials, etc.; specifically, the base 2 and the sealing cover 3 can be prepared using an injection-molded material, such as plastic, specifically PE (Polyethylene), preferably LDPE (Low Density Polyethylene), HDPE (High Density Polyethylene), or PP (Polypropylene), PA (Polyamide), PLA (Polylactic Acid) or PBAT (Butyleneadipate-co-terephthalate), etc., or a combination of any one or more of the above, such as a combination of PE / PLA.

[0045] Preferably, the base 2 and the sealing cover 3 are both made of elastic materials. For example, if the sealing cover 3 or the base 2 is made of an elastic material such as food-grade silicone, rubber, or polyethylene, the overall or partial dimensions of the sealing cover 3 can be slightly larger than the opening and the through-hole in the base 2. This allows the sealing cover 3 and the base 2 to more tightly seal the opening without affecting the sealing cover's ability to pass through the opening and fit into the base.

[0046] The sealing structure also has a pull tab 4. Preferably, the area of ​​the pull tab 4 is larger than the area of ​​the opening. The pull tab 4 is arranged on the outside of the packaging box and is located above the sealing cover 3. The sealing cover 3 is fixedly connected to the pull tab 4. The pull tab 4 serves as a force-bearing component to drive the sealing cover 3 to open or close the opening, making opening and closing easier to operate; in addition, the pull tab 4 can also shield and protect the opening to prevent dust and other impurities from falling near the opening and entering the opening when it is opened, making the use of the packaging box safer and more hygienic.

[0047] Since the connection between the base 2 and the sealing cover 3 in the present application includes but is not limited to a detachable connection method such as a snap connection, when the sealing cover 3 is pulled open from the closed state, the pull tab 4 drives the sealing cover 3 to separate from the through hole of the base 2 under the action of an external force. Therefore, the sealing cover in the present application can be embedded in the through hole of the base under the action of an external force to cooperate with the base to close the opening, and can also be separated from the through hole of the base under the action of an external force, thereby achieving the reusability of the packaging box opening, reducing production costs and being more environmentally friendly.

[0048] Preferably, the pull tab 4 can be integrally formed with the sealing cover 3, such as by injection molding. Alternatively, the pull tab 4 and sealing cover 3 can be separately molded and then fixedly connected. For example, if the sealing cover 3 also includes a top portion, the top portion is located outside the opening, and the pull tab is fixedly connected to the top portion of the sealing cover. The connection method can be hot-melt connection or adhesive bonding. The pull tab 4 can be made of a composite material, such as a composite material comprising a barrier material and a fusible material. The barrier material can be at least one of aluminum foil, barrier paper, and cellulose material, and the fusible material can be at least one selected from plastic, PLA, or PBAT. For example, the pull tab 4 can be a composite of barrier paper (such as nanocellulose paper) and PE, or a composite of aluminum foil and PE. The barrier paper or aluminum foil can also be replaced with materials such as LDPE (low-density polyethylene), HDPE (high-density polyethylene), PP (polypropylene), PA (polyamide), PLA (polylactic acid), or PBAT (butyleneadipate-co-terephthalate). The pull tab 4 can also be made of a single material, such as cardboard, preferably with a certain degree of hardness and stiffness. The cardboard weight is preferably 300g-800g, and the thickness is more preferably 2-5mm. The pull tab 4 can also be made of a cellulose material, such as wood pulp or cellulose material through dry compression molding technology. The appropriate fixing method is selected according to the material of the pull tab. If the pull tab 4 is made of aluminum foil and PE, it can be fixed by electric heating. Through electromagnetic induction, the aluminum foil in the pull tab 4 heats up, melting the PE, and then the pull tab 4 is fixed and bonded to the top of the sealing cover or the composite packaging material 1 of the packaging box. The PE in the pull tab can also be replaced by PP, PA, PLA, or PBAT. If the pull tab is made of cardboard, the sealing cover and pull tab can also be formed separately and then fixed together by gluing with an adhesive or other adhesive.

[0049] Furthermore, FIG2 is an enlarged view of portion A in FIG1 . As shown in FIG2 , when the sealing cover is closed, the outer edge of the sealing portion is preferably tightly engaged with the inner edge of the through hole of the base to close the opening. More preferably, a protrusion 8 is provided on the outer edge of the sealing portion, and a groove is provided on the inner edge of the through hole. When the sealing cover is closed, the protrusion 8 of the sealing portion abuts against the groove of the through hole to close the opening. The mating connection between the protrusion 8 and the groove can further enhance the sealing performance of the sealing cover 3 and the base 2 for the opening, effectively preventing the liquid contents from seeping out from the gap between the sealing cover 3 and the base 2. Preferably, the protrusion 8 has at least two different protrusion heights, such as the protrusion 8 has a deep portion with a larger protrusion height and a shallow portion with a smaller protrusion height. It is further preferred that the length ratio of the deep portion to the shallow portion is 1:(1-4), and the height ratio of the shallow portion to the deep portion is 1:(1.5-3); or the protrusion 8 is a symmetrical structure, and the protrusion heights on both sides of the symmetry axis are gradually set, such as gradually increasing or decreasing. The depth of the through-hole groove is set to match the raised height of the protrusion 8. By adjusting the height of the protrusion 8 and the corresponding depth of the groove, the tightness of the engagement between the protrusion and the groove and the opening force can be more flexibly balanced and adjusted, so that the opening and closing of the sealing structure are both good sealing and convenient. For example, after installation, if the shallow portion of the protrusion 8 is toward or close to the lifting position of the handle, the sealing structure can be easier to open; the higher the proportion of the shallow portion to the length of the protrusion 8, the easier it is to open; and the higher the proportion of the deep portion to the length of the protrusion 8, the better and more secure the sealing.

[0050] Furthermore, as shown in FIG2 , the base extends along the edge of the opening toward the outside of the packaging box to form a sealing ring 7. The height of the sealing ring 7 is not less than the height of the opening. Since the sealing ring 7 at the upper end of the base can completely block and wrap the edge of the opening, the sealing ring 7 can further improve the sealing performance of the packaging box opening, especially for packaging boxes made of paper-based composite packaging materials, thereby preventing liquid contents from penetrating into the interior of the packaging material when pouring, causing the opening to soften and deform and leak.

[0051] Furthermore, the closing portion may be a solid structure, and preferably the closing portion may also be a hollow structure with a hollow interior. The hollow structure can reduce the amount of material used in preparing the closing portion and enhance elasticity. Referring to FIG2 , preferably, the closing portion may also adopt a hollow structure, and an annular groove may be provided near the edge of the closing portion. Alternatively, referring to FIG3 , preferably, a hole may be opened on the closing portion or a closing portion may be provided with an annular structure.

[0052] The aforementioned annular groove, opening, and annular structure of the closure not only further reduce material usage but also make the closure more flexible, making it easier to insert and remove from the through-hole in the base. Furthermore, the bottom surface of the closure can be sloped, placing the thinner side of the closure closer to the pull tab's force-bearing position, further facilitating its removal from the base.

[0053] Furthermore, the sealing structure includes an inner film 5, which is positioned beneath the base and has an area larger than that of the base 2. The inner film 5 is fixedly attached to the bottom of the sealing portion and the inner side of the package near the base 2. Before the sealing lid is opened for the first time, the inner film completely covers the bottom of the sealing portion and the base. When the sealing lid is opened for the first time, the bonding force between the inner film 5 and the bottom of the sealing portion exceeds the tear strength of the inner film, causing the inner film to rupture, allowing the sealing lid 3 to be smoothly released from the through-hole of the base 2, thereby allowing the opening to be opened. The inner film is fixedly attached to the inside of the package and completely covers the base, effectively improving the sealing performance of the package, particularly preventing leakage of liquid contents due to pressure on the package before opening. Furthermore, the inner film 5 further ensures the sterility and safety of the internal environment of the package before the first opening, thereby extending the shelf life of the package contents. The inner film 5 can be a PE (polyethylene) film or a composite film, such as a PE / EVOH / PE composite material laminated on both sides of an EVOH (ethylene vinyl alcohol copolymer) material. EVOH can also be replaced by vapor-deposited films of metal oxides such as PVOH (Polyvinyl Alcohol), PVDC (Poly-vinylidene Chloride), PA (Polyamide) or Al2O3.

[0054] Furthermore, the sealing structure includes an outer film 6. In this embodiment, the outer film 6 is positioned outside the packaging box at the opening. Its area is smaller than that of the pull tab. The pull tab is fixedly connected to the outer film, positioning the outer film 6 between the pull tab 4 and the waterproof layer surrounding the opening. This outer film 6 prevents the pull tab 4 from directly adhering to the outermost waterproof layer of the packaging box during opening, potentially damaging the waterproof layer of the composite packaging material 1 when the pull tab 4 is pulled up. The outer film 6 can be made of PE (polyethylene) or a composite material of OPP (oriented polypropylene) and PE. OPP can also be replaced with polyester materials such as HDPE, PP, PET / PBT, etc.

[0055] In another embodiment of the present application, as shown in FIG4 , a production process for a packaging box sealing structure is also proposed. The production process includes:

[0056] Step a, punching holes in a composite packaging material for preparing a packaging box to form an opening;

[0057] Step b, providing a base at a position corresponding to the opening on the inner side of the packaging box, wherein the base is provided with a through hole;

[0058] Step c, providing a sealing cover, wherein the sealing cover has a sealing portion, which passes through the opening and is embedded in the through hole, and the sealing portion is tightly engaged with the base to seal the opening;

[0059] Step d: a pull tab is provided on the outside of the packaging box, wherein the pull tab is fixedly connected to the sealing cover and is used to drive the sealing cover to open or close the opening.

[0060] Furthermore, in another embodiment of the production process, it may also include: step e, arranging an inner membrane under the base, the area of ​​the inner membrane is larger than the area of ​​the base, the inner membrane is fixedly connected to the closing part, and the inner membrane completely covers the base and is fixedly connected to the inside of the packaging box.

[0061] Furthermore, the production process may also include setting an outer film, setting the outer film at the opening position on the outside of the corresponding packaging box, and the area of ​​the outer film is larger than the area of ​​the opening; or setting the outer film on the composite packaging material on the outside of the corresponding packaging box, and then punching holes in the outer film to form an opening.

[0062] Specifically, the sealing cover and the base can be made by injection molding; when fixedly connected, the base can be first set at the opening position on the inside of the packaging box, and then the inner film can cover the base and be fixedly connected to the inside of the packaging box; the base can also be fixedly connected to the inner film, and then the base can be set on the inside of the opening of the packaging box, and the inner film can be fixedly connected to the inside of the packaging box; the pull tab and the sealing cover can be integrally formed first, and then set on the packaging box; the sealing cover can also be set on the packaging box first, and then the pull tab can be fixedly connected to the sealing cover. The fixed connection method can be heat sealing or bonding with an adhesive. Of course, the above description of the fixing order between the outer film, inner film, sealing cover, base and pull tab is only an exemplary description and cannot be understood as a limitation of this application.

[0063] In one embodiment of the present application, a packaging box is also disclosed. The packaging box is made of a composite packaging material. The composite packaging material is first sealed longitudinally to form a tubular object and filled. Then, it is continuously sealed transversely at a distance of a single package. After cutting in the middle of the transverse seal, it is shaped into an independent packaging box. The packaging box is provided with a sealing structure as described above, or the packaging box is provided with a sealing structure prepared according to any of the above production processes. The packaging box can realize repeated opening and closing of the packaging box opening, which is not only more environmentally friendly, but also improves the sealing of the opening. Preferably, the packaging box is made of a composite packaging material, and the composite packaging material includes a base layer, a printing layer, a waterproof layer and an innermost layer. Preferably, the base layer is a paper base layer.

[0064] In summary, the technical solution of the present application has achieved at least the following technical effects: by arranging a base at the opening position on the inner side of the packaging box, and arranging a sealing cover and a pull tab on the outer side of the packaging box, the sealing cover can be embedded in the through hole of the base and connected with the base under the action of external force, and can also be separated from the through hole of the base under the action of external force, thereby realizing the reusability of the packaging box opening, reducing production costs and being more environmentally friendly; the pull tab and the base hidden on the inside of the packaging box can further improve the food safety when the packaging box is used.

[0065] It should be noted that, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more. In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements or an interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0066] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0067] Throughout this specification, references to terms such as "one embodiment," "some embodiments," and "examples" indicate that a particular feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0068] The above description is only a specific embodiment of the present invention. Under the above teachings of the present invention, those skilled in the art may make other improvements or modifications based on the above embodiments. Those skilled in the art should understand that the above description is only to better explain the purpose of the present invention, and the scope of protection of the present invention shall be based on the scope of protection of the claims.

Claims

1. A sealing structure for a packaging box, characterized in that: The sealing structure comprises: a base, a sealing cover and a pull tab, The packaging box is provided with an opening, the base is provided on the inner side of the packaging box at the position of the opening, and the base is provided with a through hole; The sealing cover has a sealing portion. When the sealing cover is closed, the sealing portion passes through the opening and is embedded in the through hole. The sealing portion is tightly engaged with the base to seal the opening. The pull tab is arranged on the outside of the packaging box, and the pull tab is fixedly connected to the sealing cover, and is used to drive the sealing cover to open or close the opening.

2. The sealing structure according to claim 1, characterized in that: When the sealing cover is closed, the outer edge of the sealing portion is tightly engaged with the inner edge of the through hole of the base to seal the opening.

3. The sealing structure according to claim 2, characterized in that: The outer edge of the closing portion is provided with a protrusion, the inner edge of the through hole is provided with a groove, and the protrusion abuts against the groove to close the opening.

4. The sealing structure according to claim 3, characterized in that: The protrusions have at least two different protrusion heights.

5. The sealing structure according to claim 4, characterized in that: The raised portion has a deep portion with a larger raised height and a shallow portion with a smaller raised height, the length ratio of the deep portion to the shallow portion is 1:(1-4), and the height ratio of the shallow portion to the deep portion is 1:(1.5-3); or the raised portion is a symmetrical structure, and the raised heights on both sides of the symmetry axis are gradually set.

6. The sealing structure according to claim 1, characterized in that: The base extends toward the outside of the packaging box along the edge of the opening to form a sealing ring, and the height of the sealing ring is not less than the height of the opening, so that the sealing ring completely covers the edge of the opening.

7. The sealing structure according to claim 1, characterized in that: The sealing portion is a solid structure or a hollow structure.

8. The sealing structure according to claim 7, characterized in that: The closed portion is provided with an opening, or the closed portion is an annular structure, or the closed portion is provided with a groove, or the bottom surface of the closed portion is inclined.

9. The sealing structure according to claim 1, characterized in that: The sealing cover also includes a top portion, which is located outside the opening, and the pull tab is fixedly connected to the top portion.

10. The sealing structure according to claim 1, characterized in that: The sealing cover and the pull tab are integrally formed; or the sealing cover and the pull tab are formed separately and then fixedly connected.

11. The sealing structure according to claim 1, characterized in that: It also includes an inner film, which is arranged below the base. The area of ​​the inner film is larger than that of the base. The inner film is fixedly connected to the closing portion. Before the sealing cover is opened for the first time, the inner film completely covers the base and is fixedly connected to the inner side of the packaging box; after the sealing cover is opened, the inner film is ruptured.

12. The sealing structure according to claim 1, characterized in that: Also includes: The outer film is arranged on the outside of the packaging box at the opening position, the area of ​​the outer film is smaller than the area of ​​the pull tab, and before the sealing cover is opened for the first time, the pull tab is fixedly connected to the outer film; after the sealing cover is opened, the pull tab is separated from the outer film.

13. A production process for a packaging box sealing structure, characterized in that: The production process comprises: Step a, punching holes in the composite packaging material used to prepare the packaging box to form an opening; Step b, providing a base at the opening position on the inner side of the corresponding packaging box, wherein the base is provided with a through hole; Step c, providing a sealing cover, wherein the sealing cover has a sealing portion, the sealing portion passes through the opening and is embedded in the through hole, and the sealing portion is tightly engaged with the base to seal the opening; Step d: a pull tab is arranged on the outside of the packaging box, wherein the pull tab is fixedly connected to the sealing cover and is used to drive the sealing cover to open or close the opening.

14. The production process according to claim 13, characterized in that: The production process also includes: Step e: an inner film is arranged below the base, the area of ​​the inner film is larger than the area of ​​the base, the inner film completely covers the base and is fixedly connected to the closing portion and the inner side of the packaging box.

15. The production process according to claim 13, characterized in that: It also includes setting an outer film, setting the outer film at the opening position on the outside of the corresponding packaging box, and the area of ​​the outer film is larger than the area of ​​the opening; or setting the outer film on the composite packaging material on the outside of the corresponding packaging box, and then punching holes in the outer film to form an opening.

16. A packaging box, characterized in that: The packaging box is provided with a sealing structure as described in any one of claims 1-12, or the packaging box is provided with a sealing structure prepared by the production process as described in any one of claims 13-15.

17. The packaging box according to claim 16, characterized in that: The packaging box is made of a composite packaging material, which includes a base layer, a printing layer, a waterproof layer and an innermost layer.

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