Meal packaging box

Abstract

The utility model discloses a meal packing box relates to meal packing box technical field, and meal packing box includes box body and lid, and the lid is covered in box body and can open and shut, is equipped with the air vent on the lid, and the air vent is covered with micropore breathable film, and the micropore breathable film is located at the outer surface of lid and is connected to the edge of air vent, and the micropore breathable film is used for the water vapor inside the box body to export outward, and is used for blocking liquid to pass. The technical scheme provided by the utility model sets up the micropore breathable film of covering air vent on the outer surface of lid, and the air permeability and the sealing property of meal packing box are considered.

Description

Technical Field

[0001] This utility model relates to the field of food packaging box technology, and in particular to a food packaging box. Background Technology

[0002] Currently, when food packaging boxes contain food that is hot or contains a lot of moisture, the water vapor produced by the food condenses on the inner surface of the lid due to the higher internal temperature compared to the external environment. This condensation not only affects the appearance and taste of the food but can also lead to dripping or spoilage. Existing food packaging box lids typically employ a fully sealed structure or only have simple vents. While a fully sealed structure can prevent liquid leakage, it hinders the expulsion of internal moisture, exacerbating the condensation problem; while simple vents pose a risk of poor sealing, allowing liquid leakage or the entry of external contaminants. Therefore, the existing lid structures of food packaging boxes present a difficult challenge in achieving both effective ventilation and maintaining a tight seal. Utility Model Content

[0003] The main purpose of this utility model is to propose a food packaging box that balances breathability and airtightness.

[0004] To achieve the above objectives, the present invention proposes a food packaging box, comprising a box body and a lid. The lid is closable and covers the box body. The lid has a vent, which is covered with a microporous breathable membrane. The microporous breathable membrane is disposed on the outer surface of the lid and connected to the edge of the vent. The microporous breathable membrane is used to allow water vapor inside the box body to escape and to prevent liquid from passing through.

[0005] In one embodiment, the microporous breathable membrane is fixed to the cover by adhesive bonding or ultrasonic welding.

[0006] In one embodiment, the food packaging box further includes an adhesive layer, which is disposed on the outer surface of the cover along the edge of the vent, and the microporous breathable membrane is bonded to the cover through the adhesive layer.

[0007] In one embodiment, the ratio of the distance from the inner periphery to the outer periphery of the adhesive layer to the width of the microporous breathable membrane is 1 / 5 to 1 / 4.

[0008] In one embodiment, the distance from the inner periphery to the outer periphery of the adhesive layer is 0.5 mm to 1.5 mm.

[0009] In one embodiment, the box body includes a protrusion, a flat portion, and a connecting portion. The flat portion surrounds the outer periphery of the protrusion and is connected to the inner periphery of the connecting portion. When the lid is closed, the protrusion protrudes outward from the box body relative to the flat portion. The vent is located on the protrusion, and the connecting portion is used to connect the box body.

[0010] In one embodiment, the vent is provided, and one of the vents is provided on the protrusion.

[0011] In one embodiment, a plurality of air vents are provided, and the plurality of air vents are provided on the protrusion.

[0012] In one embodiment, a plurality of air vents are provided, and the plurality of air vents are provided on the straight portion.

[0013] In one embodiment, a plurality of air vents are provided, and the plurality of air vents are provided on the protruding portion and the straight portion.

[0014] In one embodiment, the connection between the adjacent side walls of the protrusion is configured with a rounded transition.

[0015] In one embodiment, the connecting portion has a slot, and the edge of the box opening of the box body is engaged in the slot.

[0016] In one embodiment, the microporous breathable membrane is made of a microporous polymer material.

[0017] In one embodiment, the pore size of the microporous breathable membrane is from 0.1 μm to 10 μm.

[0018] In one embodiment, the vent is a round hole or a polygonal hole.

[0019] In one embodiment, the ratio of the length of the vent in the length direction of the cover to the length of the cover is 1 / 7 to 1 / 5.

[0020] In one embodiment, the ratio of the width of the vent in the width direction of the cover to the width of the cover is 1 / 7 to 1 / 5.

[0021] This invention solves the problem of balancing airtightness and breathability in traditional packaging boxes by setting a microporous breathable membrane covering the vents on the outer surface of the lid. Compared to a completely sealed structure, this food packaging box allows water vapor to escape in an orderly manner, significantly reducing the possibility of condensation inside the box. This maintains the appearance and taste of the food, preventing it from becoming damp or spoiling due to water droplets. Compared to designs with only simple vents, the microporous breathable membrane provides a reliable liquid seal barrier while achieving breathability, ensuring good sealing performance during transportation and carrying, preventing leakage and external contamination. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the structure of an embodiment of the food packaging box provided by this utility model;

[0024] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0025] Figure 3 A top view of an embodiment of the cover provided by this utility model;

[0026] Figure 4 A top view of another embodiment of the cover provided by this utility model;

[0027] Figure 5 A top view of yet another embodiment of the cover provided by this utility model;

[0028] Figure 6 A top view of yet another embodiment of the cover provided by this utility model;

[0029] Figure 7 This is a top view of another embodiment of the cover provided by this utility model.

[0030] Explanation of icon numbers:

[0031] 100, Box body; 200, Lid body; 300, Microporous breathable membrane; 400, Adhesive layer; 210, Protrusion; 220, Straight part; 230, Connecting part; 231, Slot; 240, Vent.

[0032] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0034] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0035] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0036] This utility model proposes a food packaging box.

[0037] Please see Figures 1 to 3 In one embodiment of this utility model, the food packaging box includes a box body 100 and a lid 200. The lid 200 is closable and covers the box body 100. A vent 240 is provided on the lid 200. A microporous breathable membrane 300 is covered on the vent 240. The microporous breathable membrane 300 is disposed on the outer surface of the lid 200 and connected to the edge of the vent 240. The microporous breathable membrane 300 is used to allow water vapor inside the box body 100 to be discharged to the outside and to block liquid from passing through.

[0038] Food packaging boxes can be used in various fields such as takeout, ready-to-eat foods, frozen foods, airline catering, hospital nutrition meal delivery, school and corporate canteen catering, outdoor activities, and home food storage. Food packaging boxes can effectively expel internal moisture and prevent condensation, making them especially suitable for packaging foods that are prone to generating a lot of water vapor when sealed, such as hot food, soups, steamed foods, and freshly cooked pastries.

[0039] Specifically, the food packaging box includes a box body 100 and a lid 200. The lid 200 can be opened and closed to cover the box body 100. When the lid 200 is closed on the box body 100, the box body 100 and the lid 200 form a closed space to contain food. A vent 240 is provided on the lid 200, and a microporous breathable membrane 300 is covered on the vent 240. The microporous membrane is located on one side of the outer surface of the lid 200 and is sealed to the edge of the vent 240.

[0040] The microporous breathable membrane 300 is a material with numerous micro- and nano-sized pores, typically ranging from 0.1 μm to 10 μm in pore size. Water vapor exists in gaseous form as water vapor molecules, with a small molecular size of approximately 0.0004 μm in diameter, allowing them to pass freely through the micropores of the microporous breathable membrane 300. Liquid water molecules, being larger and affected by surface tension, cannot penetrate the micropores of the microporous breathable membrane 300, thus achieving waterproof and leak-proof functions. It allows water vapor generated by hot food inside the food container to escape while preventing soup from leaking out through the vents 240, while also preventing external dust or contaminants from entering, thereby ensuring the dryness of the packaging interior and the protection against external contamination.

[0041] Understandably, when food packaging contains food that is hot or contains a lot of moisture, the water vapor generated inside can be discharged through the microporous breathable membrane 300, achieving pressure balance inside and outside the box and reducing condensation on the inner surface of the lid. This reduces the risk of condensation dripping onto the food surface, preventing the food from becoming soft or spoiling due to moisture, and ensuring the food remains dry and visually appealing. The microporous breathable membrane 300 also effectively blocks liquids; even if the food container is tilted or bumped during transport, soup will not overflow from the vent 240, preventing leakage and contamination of the outer packaging or the user's clothing, thus improving safety. Simultaneously, the microporous breathable membrane 300 prevents external liquids or contaminants from entering the box. For example, in rainy weather, it effectively prevents rainwater from seeping into the box 100 and contaminating the takeout food, thereby effectively reducing customer complaints.

[0042] The outer surface of the lid 200 refers to the side of the lid 200 facing away from the interior of the box 100 when it is closed on the box 100; the other side of the lid 200 facing the interior of the box 100 is the inner surface of the lid 200. The microporous breathable membrane 300 is disposed on the outer surface of the lid 200, facilitating its processing and assembly. Simultaneously, the microporous breathable membrane 300's location on the outer surface of the lid 200 keeps it relatively further away from the food inside the box, effectively preventing it from being contaminated or clogged by food residue, grease, or broth, thus maintaining its stable and reliable breathability over a long period. Of course, in other embodiments, the microporous breathable membrane 300 can also be disposed on the inner surface of the lid 200; it can also be connected to the inner peripheral wall of the vent 240.

[0043] The technical solution of this utility model solves the problem of balancing airtightness and breathability in traditional packaging boxes by setting a microporous breathable membrane 300 covering the vent 240 on the outer surface of the lid 200. Compared with an overall sealed structure, the food packaging box of this utility model allows water vapor to escape in an orderly manner, significantly reducing the possibility of condensation inside the box, thereby maintaining the appearance integrity and taste quality of the food and preventing the food from getting damp or spoiling due to water droplets. Compared with a design with only simple vent holes, the microporous breathable membrane 300 provides a reliable liquid seal barrier while achieving the function of breathability, ensuring that the food packaging box has good sealing performance during transportation and carrying, preventing soup leakage and external contamination.

[0044] It is worth mentioning that when moisture is released through the microporous breathable membrane 300, the heat from the food inside the container 100 can dissipate at a slow rate, thus achieving good heat retention while effectively removing moisture. The microporous structure and material properties of the microporous breathable membrane 300 have a certain barrier effect on heat conduction, slowing down the rapid loss of heat through convection and conduction, preventing the food from being affected by a sudden drop in temperature, thus extending the warm eating time of the food and improving the appearance, aroma, and overall experience of the food when the lid is opened.

[0045] In one implementation, please refer to Figure 2 and Figure 3 The microporous breathable membrane 300 is fixed to the cover 200 by adhesive bonding.

[0046] The microporous breathable membrane 300 can be firmly attached to the cover 200 using food-grade adhesive, ensuring a strong connection and meeting hygiene and safety requirements. The adhesive fills tiny gaps, creating a good seal and effectively preventing liquid leakage and the ingress of external contaminants. Furthermore, the bonding process is relatively simple and cost-effective.

[0047] In another embodiment, the microporous breathable membrane 300 is fixed to the cover 200 by ultrasonic welding.

[0048] Ultrasonic welding achieves a fusion bond between the microporous breathable membrane 300 and the cover 200 through high-frequency vibration, offering advantages such as no need for additional auxiliary materials, excellent sealing, and high production efficiency. The joints formed by ultrasonic welding exhibit high strength and durability, and are not easily damaged by changes in the external environment (such as temperature and humidity). Furthermore, the welding process is rapid, contributing to improved production efficiency.

[0049] The microporous breathable membrane 300 can be fixed by adhesive bonding or ultrasonic welding to ensure a stable and reliable connection between the microporous breathable membrane 300 and the cover body 200, preventing it from falling off or creating a leakage path during use.

[0050] In one implementation, please refer to Figure 2 and Figure 3 The food packaging box also includes an adhesive layer 400, which is disposed on the outer surface of the cover 200 along the edge of the vent 240, and the microporous breathable membrane 300 is bonded to the cover 200 through the adhesive layer 400.

[0051] An adhesive layer 400 is applied to the outer surface of the cover 200 and arranged along the edge of the vent 240, forming a ring-shaped bonding area. The adhesive layer 400 firmly adheres the edge portion of the microporous breathable membrane 300 to the cover 200, ensuring that the microporous breathable membrane 300 completely covers and seals the vent 240. By precisely controlling the bonding area to be located only at the edge of the membrane material, the microporous structure in the central area of ​​the microporous breathable membrane 300 remains exposed and unobstructed, without affecting its breathability. Simultaneously, it prevents adhesive from seeping into the micropores of the microporous breathable membrane 300 and causing blockage, ensuring that water vapor can escape smoothly. Compared to point or localized bonding, the ring-shaped adhesive layer 400 provides a more uniform stress distribution, improving overall sealing stability.

[0052] In one implementation, please refer to Figure 2 and Figure 3 The ratio of the distance from the inner periphery to the outer periphery of the adhesive layer 400 to the width of the microporous breathable membrane 300 is 1 / 5 to 1 / 4.

[0053] The distance from the inner periphery to the outer periphery of the adhesive layer 400 refers to the radial width (or annular bandwidth) of the adhesive layer 400 on the plane, that is, the distance from the inner edge surrounding the vent 240 to the outer edge of the adhesive layer 400, which is the width of an annular region, denoted as W1. The width of the microporous breathable membrane 300 is the dimension of its overall size in the direction corresponding to the adhesive area when covering the vent 240, such as the diameter of a circular membrane or the side length of a square membrane, denoted as W2. 1 / 5 ≤ W1 / W2 ≤ 1 / 4 indicates that the annular bandwidth of the adhesive layer 400 accounts for approximately 1 / 5 to 1 / 4 of the total width of the microporous breathable membrane 300. The adhesive layer 400 has a width of no less than 1 / 5 of the membrane width, meaning there is sufficient bonding area to ensure the microporous breathable membrane 300 is firmly fixed to the cover 200. This prevents the microporous breathable membrane 300 from warping, falling off, or failing to seal due to excessively narrow bonding areas during transportation, opening and closing, or changes in internal air pressure. Simultaneously, it avoids stress concentration on the tiny contact surfaces caused by an excessively narrow bonding area, which could lead to membrane tearing under tension or thermal expansion and contraction. The adhesive layer 400 has a width of no more than 1 / 4, avoiding occupying too much membrane surface area, which could lead to partial coverage or blockage of micropores, affecting breathability. By controlling W1 / W2 to be between 1 / 5 and 1 / 4, it ensures bonding reliability, maximizes the preservation of the central breathable area, provides good stress dispersion, and improves structural durability.

[0054] In one implementation, please refer to Figure 2 and Figure 3 The distance from the inner periphery to the outer periphery of the adhesive layer 400 is 0.5 mm to 1.5 mm.

[0055] When the width of the adhesive layer 400 is less than 0.5mm, the bonding area is too small, making it prone to demolding and curling during thermal expansion and contraction, transportation vibration, or opening operations. When 0.5mm ≤ W1, sufficient bonding reliability can be guaranteed under various usage environments. When W1 ≤ 1.5mm, appearance defects such as whitening and wrinkling caused by an excessively wide adhesive layer can be avoided. By designing the width of the adhesive layer 400 to be 0.5mm ≤ W1 ≤ 1.5mm, the width of the adhesive layer 400 is appropriate and uniform, resulting in a smooth appearance after film application without obvious adhesive marks, thereby improving product quality and consumer acceptance.

[0056] In one implementation, please refer to Figures 1 to 3 The box body 100 includes a protruding part 210, a flat part 220 and a connecting part 230. The flat part 220 surrounds the outer periphery of the protruding part 210 and is connected to the inner periphery of the connecting part 230. When the cover 200 is closed, the protruding part 210 protrudes outward from the box body 100 relative to the flat part 220. A vent 240 is provided on the protruding part 210. The connecting part 230 is used to connect the box body 100.

[0057] The protrusion 210 is a partially raised structure located in the upper region of the box body 100, higher than the flat portion 220. The vent 240 and the microporous breathable membrane 300 are located here. The flat portion 220 surrounds the protrusion 210 in a horizontal or near-horizontal plane, serving as the reference surface for the sealing fit of the cover 200. The connecting portion 230 is located outside the flat portion 220 and is used to connect and fix the cover 200 to the box body 100. The connecting portion 230 can be a groove 231, a protrusion, a threaded structure, etc.

[0058] When the lid 200 is closed on the box 100, the protrusion 210 protrudes outward relative to the flat portion 220, away from the box 100. The vent 240 is located on the protrusion 210, and is relatively farther away from the food inside the box 100. The heat vapor generated by the food has a low density and naturally rises. Placing the vent 240 at the highest point facilitates the rapid accumulation and discharge of water vapor, reducing the possibility of condensation in other areas inside the lid. In addition, the protrusion 210 is higher than the flat portion 220, so even if the box 100 is tilted or there is soup inside, the liquid is less likely to overflow the flat portion 220 and reach the vent 240 of the protrusion 210. Combined with the waterproof properties of the microporous breathable membrane 300, high-level venting is achieved, greatly reducing the risk of leakage.

[0059] In other embodiments, the protrusion 210 may not be provided, that is, the protrusion 210 and the straight portion 220 are located on the same plane.

[0060] In one implementation, please refer to Figure 3 A vent 240 is provided, and a vent 240 is provided on the protrusion 210.

[0061] The cover 200 has only one vent 240, reducing the difficulty of mold processing and facilitating automated film application. Only one fixing operation of the microporous breathable membrane 300 is required at a fixed position, reducing the risk of seal failure due to multiple pores and improving yield. Simultaneously, hot air and water vapor tend to rise; placing the single vent 240 on the protrusion 210 creates a natural confluence effect, allowing internal moisture to quickly concentrate at the vent 240 and be discharged, avoiding airflow dispersion and path disorder problems that may occur with multiple pores, thus improving exhaust efficiency. Furthermore, the absence of multiple small holes makes the overall appearance more aesthetically pleasing and concise, preventing users from mistakenly believing it to be a sign of damage or other quality issues.

[0062] In one implementation, please refer to Figure 4 Multiple vents 240 are provided, and multiple vents 240 are provided on the protrusion 210.

[0063] When containing hot, high-humidity foods (such as soups and steamed dishes), steam is generated rapidly, and a single vent 240 may not be able to expel the moisture in time. Setting multiple vents 240 can significantly increase the total ventilation area, accelerate the expulsion of water vapor, and reduce the rate of pressure and humidity rise inside the container. The distribution of multiple vents 240 also ensures more even gas expulsion, preventing uneven stress on the membrane material caused by concentrated local airflow. If one vent 240 fails due to blockage (such as oil stains), the remaining vents 240 can continue to function, preventing overall functional loss. Each vent 240 can be independently fitted with a microporous breathable membrane 300 for easy local replacement; alternatively, a larger microporous membrane can cover all vents 240 and be fixed together using an adhesive layer 400, simplifying the assembly process.

[0064] In one implementation, please refer to Figure 5 Multiple vents 240 are provided, and multiple vents 240 are provided in the straight part 220.

[0065] With multiple vents 240 located on the flat section 220, the need for an additional protruding structure 210 is eliminated, resulting in a flatter overall cover 200, reduced structural complexity, and simplified mold design. The concentration of multiple vents 240 on the flat plane allows for complete coverage with a single continuous microporous membrane, facilitating automated film application and improving production efficiency. Furthermore, the protruding section 210 is unnecessary, preventing moisture from condensing inside it.

[0066] In one implementation, please refer to Figure 6 Multiple vents 240 are provided, and multiple vents 240 are provided on the protrusion 210 and the straight part 220.

[0067] Both the protruding part 210 and the straight part 220 are provided with vents 240. The vents 240 at the protruding part 210 utilize the principle of hot air rising to quickly expel most of the water vapor. The vents 240 at the straight part 220 can serve as auxiliary exhaust points to help exhaust moisture near the side walls or corners, reduce local accumulation, achieve coordinated exhaust at the center and edges, and optimize the internal airflow organization.

[0068] In one implementation, please refer to Figure 3 The connection between the adjacent two side walls of the protrusion 210 is configured with a rounded transition.

[0069] The connection between the two adjacent side walls of the protrusion 210 refers to the corner of the protrusion 210. By forming a smooth curved surface around the protrusion 210, it helps the rising water vapor inside to flow smoothly to the vent 240, avoiding the formation of local eddies or stagnant areas due to the disturbance of sharp corners, thus improving exhaust efficiency. Moreover, the connection is achieved through a smooth transition with a rounded curved surface, avoiding stress concentration and structural abrupt changes. In the injection molding process, right-angle structures can easily lead to mold jamming or demolding difficulties for plastic parts. The rounded corner design facilitates uniform flow and filling of the plastic melt, reduces defects such as bubbles and shrinkage, makes demolding smoother, reduces mold wear, and improves yield and production speed. In addition, right angles or sharp corners are prone to accumulating oil, food residue, or condensation. The smooth, rounded corner surface has no dead corners, making it less likely to trap dirt and grime, and easier to clean, making it suitable for reusable environmentally friendly lunch boxes.

[0070] In other embodiments, the connection between the adjacent side walls of the protrusion 210 is configured as an angle; or the outline of the protrusion 210 is circular or elliptical.

[0071] In one implementation, please refer to Figure 1 The connecting part 230 has a slot 231, and the edge of the box opening of the box body 100 is placed in the slot 231.

[0072] The connecting part 230 is used to connect the lid 200 and the box 100. A slot 231 is formed inside the connecting part 230 to accommodate the edge of the box opening of the box 100. The box opening edge refers to the outer edge of the top opening of the box 100, and has a certain thickness and rigidity. Users only need to align the lid 200 with the box opening and press to close it; disassembly is achieved by forcefully prying it open, requiring no additional tools. This is particularly suitable for high-efficiency scenarios such as takeout, fast food, and self-service dining. The slot 231 forms a tight seal with the box opening edge, effectively preventing lateral spillage of soup. Elastic sealing ribs or soft rubber strips can be added inside the slot 231 to further improve airtightness and waterproofing. The slot 231 structure has a certain locking function, resisting shaking and bumps during transportation, preventing the lid 200 from automatically opening due to air pressure changes or collisions, ensuring food safety and hygiene.

[0073] In other embodiments, the opening of the box body 100 is configured as a slot 231, and the connecting part 230 is configured as a protrusion, and the two are engaged; or the side wall of the box body 100 is provided with a protrusion, and the connecting part 230 is configured as a buckle, and the two are engaged.

[0074] In one embodiment, the microporous breathable membrane 300 is made of a microporous polymer material.

[0075] Microporous polymer materials can be manufactured into microporous breathable membranes 300 through various processes such as polymer matrix stretching, sintering, and electrospinning. This results in a large number of tiny, uniformly distributed pores, achieving the effect of air permeability without water permeability. Microporous polymer materials can be selected from polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), polyurethane, polypropylene, polyethylene, polyethylene terephthalate (PET), etc., and can be one of these materials, or a mixture or copolymer of two or more of them.

[0076] In other embodiments, the microporous breathable membrane 300 may also be made of a microporous metal material.

[0077] In one embodiment, the pore size of the microporous breathable membrane 300 is from 0.1 μm to 10 μm.

[0078] When the pore size of the microporous breathable membrane 300 is less than 10μm, it can effectively block liquid droplets and soup leakage, as well as prevent most microorganisms and particulate contaminants from entering the box 100, ensuring the airtightness of the packaging and food safety. When the pore size of the microporous breathable membrane 300 is greater than 0.1μm, it allows water vapor molecules to pass through smoothly, achieving good breathability and avoiding condensation caused by water vapor accumulation. The pore size of the microporous breathable membrane 300 is from 0.1μm to 10μm. Its microporous structure can form a capillary barrier, using liquid surface tension to prevent liquid water penetration while not hindering gas diffusion, thus providing necessary waterproof and anti-pollution capabilities while ensuring good breathability.

[0079] In one implementation, please refer to Figure 3 and Figure 7 The vent 240 is a round hole or a polygonal hole.

[0080] The vent 240 can be a through hole with a circular cross-section, or a regular or irregular geometric shape with multiple straight sides, such as a triangular hole, quadrilateral hole, pentagonal hole, hexagonal hole, rhombus, trapezoidal hole, or other irregularly shaped hole. A circular vent 240 provides uniform stress distribution, minimal stress concentration under load, and is less prone to cracking. It is also easy to manufacture, resulting in low cost and high precision. A polygonal vent 240 increases the effective ventilation area. For the same circumscribed circle size, structures such as regular hexagons can provide a larger opening area, increasing the airflow per unit time. When multiple vents 240 need to be closely arranged, hexagons can achieve seamless splicing, maximizing space utilization.

[0081] In other embodiments, the vent 240 may also be other irregular shapes, such as petal-shaped, star-shaped, teardrop-shaped, etc.

[0082] In one implementation, please refer to Figure 3The ratio of the length of the vent 240 in the longitudinal direction of the cover 200 to the length of the cover 200 is 1 / 7 to 1 / 5.

[0083] The length of the vent 240 along the length of the cover 200 refers to the maximum projected dimension of the vent 240 along the length of the cover 200, denoted as L1. If the vent 240 is a circular hole, this length refers to its diameter; if it is a polygonal hole (such as a rectangle or hexagon), it refers to its maximum circumscribed dimension along the length. The length of the cover 200 is denoted as D1. 1 / 7 ≤ L1 / D1 ≤ 1 / 5 indicates that the dimension of the vent 240 along the length is 1 / 7 to 1 / 5 of the total length of the cover 200. By controlling 1 / 7 ≤ L1 / D1, the vent 240 is ensured to have sufficient ventilation area, preventing slow water vapor discharge and condensation, thus achieving effective ventilation. By controlling L1 / D1 ≤ 1 / 5, an excessively large opening is avoided, which would weaken the structural strength of the cover 200, ensuring the overall rigidity and compressive strength of the cover 200. Especially during stacking and transportation, deformation or cracking of large opening areas is prevented.

[0084] In one implementation, please refer to Figure 3 The ratio of the width of the vent 240 in the width direction of the cover 200 to the width of the cover 200 is 1 / 7 to 1 / 5.

[0085] The width of the vent 240 in the width direction of the cover 200 refers to the maximum projected dimension of the vent 240 along the width direction of the cover 200, denoted as L2. If the vent 240 is a circular hole, this width refers to its diameter; if it is a polygonal hole (such as a rectangle or hexagon), it refers to its maximum circumscribed dimension in the width direction. The width of the cover 200 is denoted as D2. 1 / 7≤L2 / D2≤1 / 5 indicates that the dimension of the vent 240 in the width direction accounts for 1 / 7 to 1 / 5 of the total width of the cover 200. By controlling 1 / 7≤L2 / D2, the vent 240 is ensured to have sufficient ventilation area, avoiding slow water vapor discharge and easy condensation accumulation, thereby achieving effective venting. By controlling L2 / D2≤1 / 5, excessively large openings are avoided, which would excessively weaken the structural strength of the cover 200, ensuring the overall rigidity and compressive strength of the cover 200. Especially during stacking and transportation, deformation or cracking of large opening areas is prevented.

[0086] The above description is merely an exemplary embodiment of the present utility model and does not limit the scope of protection of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present utility model.

Claims

1. A food packaging box, characterized in that, The device includes a box body and a lid. The lid is closable and covers the box body. The lid has a vent, and the vent is covered with a microporous breathable membrane. The microporous breathable membrane is located on the outer surface of the lid and connected to the edge of the vent. The microporous breathable membrane is used to allow water vapor inside the box body to escape and to prevent liquid from passing through.

2. The food packaging box as described in claim 1, characterized in that, The microporous breathable membrane is fixed to the cover by adhesive bonding or ultrasonic welding.

3. The food packaging box as described in claim 2, characterized in that, The food packaging box also includes an adhesive layer, which is disposed on the outer surface of the cover along the edge of the vent, and the microporous breathable membrane is bonded to the cover through the adhesive layer.

4. The food packaging box as described in claim 3, characterized in that, The ratio of the distance from the inner periphery to the outer periphery of the adhesive layer to the width of the microporous breathable membrane is 1 / 5 to 1 / 4. And / or, the distance from the inner periphery to the outer periphery of the adhesive layer is 0.5 mm to 1.5 mm.

5. The food packaging box as described in claim 1, characterized in that, The box body includes a protruding part, a flat part, and a connecting part. The flat part surrounds the outer periphery of the protruding part and is connected to the inner periphery of the connecting part. When the lid is closed, the protruding part protrudes outward from the box body relative to the flat part. The vent is located on the protruding part, and the connecting part is used to connect the box body.

6. The food packaging box as described in claim 5, characterized in that, The ventilation port is provided, and one of the ventilation ports is provided on the protrusion; And / or, the ventilation openings are provided in multiple locations, and the multiple ventilation openings are located on the protruding portion and / or the straight portion.

7. The food packaging box as described in claim 5, characterized in that, The connection between the adjacent side walls of the protrusion is configured with a rounded corner transition; And / or, the connecting part is formed with a slot, and the edge of the box opening of the box body is engaged in the slot.

8. The food packaging box as described in claim 1, characterized in that, The microporous breathable membrane is made of microporous polymer material; And / or, the pore size of the microporous breathable membrane is from 0.1 μm to 10 μm.

9. The food packaging box as described in claim 1, characterized in that, The vent is a round hole or a polygonal hole.

10. The food packaging box as described in claim 1, characterized in that, The ratio of the length of the vent in the length direction of the cover to the length of the cover is 1 / 7 to 1 / 5; And / or, the ratio of the width of the vent in the width direction of the cover to the width of the cover is 1 / 7 to 1 / 5.

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