Leak-proof heat-sensitive adhesive paper box
By setting continuous leak-proof folds at the four corners of the cardboard box and using heat-sensitive adhesive for heat sealing, combined with a snap-fit structure, the problems of traditional cardboard boxes softening and detaching at high temperatures and poor aesthetics are solved, achieving a fully leak-proof and stable sealing effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DES HESHAN PAPER PRODS
- Filing Date
- 2025-06-27
- Publication Date
- 2026-06-05
AI Technical Summary
Existing leak-proof cardboard boxes are prone to softening and detachment at high temperatures, leading to liquid leakage. Furthermore, traditional fixing methods are not secure, have poor aesthetics, and cannot achieve a complete leak-proof effect.
The box is fitted with continuous leak-proof folds at the four corners and heat-sealed with heat-sensitive adhesive. The lid is fixed to the box body with a snap-fit structure, achieving a complete leak-proof effect while maintaining an aesthetically pleasing appearance.
It achieves a firm bond even at high temperatures, preventing leakage. The hidden snap-fit structure improves the stability and aesthetics of the lid, solving the leakage-proof shortcomings of traditional cardboard boxes.
Smart Images
Figure CN224324296U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of paper box products, and more particularly to a leak-proof thermal adhesive paper box that achieves full leak-proof effect throughout the box. Background Technology
[0002] Currently, traditional leak-proof cardboard boxes used for food packaging are made of coated paper, meaning that coated paper is pasted onto the inner wall of the box. Traditional leak-proof cardboard boxes are fixed at the four corners by directly gluing or attaching paper pieces to the side corners, or by heat sealing. When using glue to form a leak-proof box, the glue may soften or detach when heated, and the glue cannot be applied evenly across the entire height of the corners (usually using a dotted application method). With this method, sauces or other liquids inside the food can easily leak through the gaps where there is no glue at the corners, resulting in extremely poor leak-proof performance. Even if glue is applied across the entire height of the corners, the glued areas may soften and detach due to high temperatures, leading to further leakage and failure to prevent leaks. In addition, traditional leak-proof cardboard boxes also have other problems, as follows: (1) The fixing method of the lid and the body lid of the traditional leak-proof cardboard box is usually to glue the front end of the lid to the body, or to insert the front end of the lid into the opening through a tongue; such fixing methods are single-point fixing methods between the lid and the body, which have the problem that the lid is not fixed to the body on both sides and is easy to be flipped up, and the gap between the two is large, resulting in poor sealing and reduced leak-proof performance; in addition, the glue method or the insertion method will have the problem of leak-proof performance. The leak-proof box has visible adhesive tape, tongue, or slot, making the whole leak-proof box less aesthetically pleasing. If the adhesive tape is placed inside the lid and attached to the box body, it is easy for the lid to be attached to the outside of the box body before it is fully closed. This means that the lid is fixed before it is fully closed, which not only results in poor performance of the leak-proof box, but also means that when you need to open the leak-proof box to take out food, you can only do so by breaking the lid, which causes irreversible damage to the lid. After the leak-proof box is used, it no longer has the leak-proof function. (2) The front and left and right sides of the traditional leak-proof box generally do not have leak-proof folds or skirts. They rely on the folded skirt of the lid to cover the sides of the leak-proof box, which generally has a covering effect, but the leak-proof effect on the front and left and right sides is not good, and the purpose of full leak-proof is not achieved.
[0003] Therefore, it is necessary to improve the existing leak-proof cardboard box structure and develop a leak-proof cardboard box product that can maintain a firm adhesion and have a complete leak-proof effect regardless of temperature. Summary of the Invention
[0004] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a leak-proof thermal adhesive cardboard box. This leak-proof thermal adhesive cardboard box addresses the problem that current market products lack full leak-proof performance and cannot meet the ever-changing new leak-proof requirements. It solves the problem that traditional heat-sealed cardboard boxes cannot achieve full leak-proof performance. This leak-proof heat-sensitive adhesive cardboard box features seamless leak-proof folds at each of the four corners, integrated with the box body. These folds are heat-sealed using heat-sensitive adhesive to ensure a firm bond at the corners, preventing liquid leakage and achieving a complete leak-proof effect. The adhesive strength remains unaffected by the high temperatures of food, eliminating any potential leakage. Furthermore, the lid and box body are locked together via a snap-fit mechanism, ensuring a secure fit. This not only allows the lid to close properly and maintains the box's appearance when opened, but also conceals the snap-fit structure, preserving an aesthetically pleasing look. It also solves the problem of traditional cardboard boxes only having two points of fixation between the front and rear ends and the box body. This heat-sensitive adhesive cardboard box's snap-fit structure provides three points of fixation—on the left, right, and rear sides—improving the stability and strength of the closed lid and box body.
[0005] The technical solution adopted by this utility model to solve its technical problem is: a leak-proof thermal adhesive paper box, including a paper box body and a paper box cover that is integrally connected with the paper box body, and coated paper is pasted on the inner wall surface of the paper box body and the paper box cover.
[0006] Furthermore, the cardboard box includes a base plate, and a front side plate, a rear side plate, a left side plate, and a right side plate that are connected to the base plate at the front, back, left, and right sides respectively and are of the same height. At each of the four corners of the cardboard box is an integrally connected, uninterrupted leak-proof folding piece, forming a connection between the front side plate and the left side plate, the front side plate and the right side plate, the rear side plate and the left side plate, and the rear side plate and the right side plate. The leak-proof folding piece consists of two symmetrically arranged triangular folding pieces. Both outer ends of the left and right side plates are provided with side plate heat-sensitive adhesive, and the outer side of the leak-proof folding piece facing the side plate heat-sensitive adhesive is provided with a heat-sealed adhesive that firmly adheres to the side plate heat-sensitive adhesive.
[0007] Furthermore, the carton lid includes a lid plate connected to the rear side panel, a left folding plate and a right folding plate that are folded inward by 90 degrees on both sides of the lid plate, and a front folding plate that is folded inward by 90 degrees at the front end of the lid plate.
[0008] Furthermore, the front panel, left panel, and right panel are respectively provided with a front leak-proof baffle, a left leak-proof baffle, and a right leak-proof baffle that are folded inward by 90 degrees to form a horizontal state.
[0009] Furthermore, the front folding plate of the box lid has box lid cards that fold inward at 90 degrees at both ends, and the outer middle position of the box lid card has a heat-sensitive adhesive that forms a heat seal firmly with the inner side of the left and right folding plates of the box lid; the top of the leak-proof folding piece at the connection position between the front side plate and the left side plate, and the connection position between the front side plate and the right side plate has a box body card that folds downward; when the box lid and the box body are closed, the bottom of the box body card is inserted into the gap between the top of the box lid card and the front folding plate of the box lid to form a tight fixation.
[0010] Furthermore, the front, rear, left, and right side panels are all angled outwards to form a trapezoidal shape that is wider at the top and narrower at the bottom of the box.
[0011] Furthermore, the width of the box cover card is smaller than the width of the front fold plate, the left fold plate, and the right fold plate of the box cover; after the box cover card is pasted and fixed on the left fold plate and the right fold plate of the box cover, the distance between the top of the box cover card and the box cover plate is smaller than the width of the box body card.
[0012] Furthermore, the height of the leak-proof folding panel is consistent with the height of the front panel, rear panel, left panel, and right panel.
[0013] In summary, the leak-proof thermal adhesive cardboard box of this utility model addresses the problem that current market products lack full leak-proof performance and cannot meet the ever-changing new leak-proof requirements, thus solving the problem that traditional heat-sealed cardboard boxes cannot achieve full leak-proof performance. This leak-proof heat-sensitive adhesive cardboard box features seamless leak-proof folds at each of the four corners, integrated with the box body. These folds are heat-sealed using heat-sensitive adhesive to ensure a firm bond at the corners, preventing liquid leakage and achieving a complete leak-proof effect. The adhesive strength remains unaffected by the high temperatures of food, eliminating any potential leakage. Furthermore, the lid and box body are locked together via a snap-fit mechanism, ensuring a secure fit. This not only allows the lid to close properly and maintains the box's appearance when opened, but also conceals the snap-fit structure, preserving an aesthetically pleasing look. It also solves the problem of traditional cardboard boxes only having two points of fixation between the front and rear ends and the box body. This heat-sensitive adhesive cardboard box's snap-fit structure provides three points of fixation—on the left, right, and rear sides—improving the stability and strength of the closed lid and box body. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of a leak-proof thermal adhesive paper box in Embodiment 1 of this utility model when the paper box is fully unfolded without support;
[0015] Figure 2 yes Figure 1 Rear view;
[0016] Figure 3 This is a top view of the leak-proof thermal adhesive paper box of Embodiment 1 of this utility model when the paper box cover is not closed and the paper box is not heat-sealed and fixed.
[0017] Figure 4 This is a top view of the leak-proof thermal adhesive paper box of Embodiment 1 of this utility model when the paper box lid is not closed;
[0018] Figure 5 This is a right-side view of the structure of a leak-proof thermal adhesive paper box in Embodiment 1 of this utility model when the paper box lid is not closed.
[0019] Figure 6 This is a schematic diagram of the structure of the paper box lid according to Embodiment 1 of this utility model;
[0020] The labels in the attached diagram are as follows: 1. Carton body; 2. Carton lid; 3. Base plate; 4. Front side plate; 5. Rear side plate; 6. Left side plate; 7. Right side plate; 8. Leak-proof folding flap; 9. Side plate heat-sensitive adhesive; 10. Folding flap heat-sensitive adhesive; 11. Box lid plate; 12. Box lid left folding plate; 13. Box lid right folding plate; 14. Box lid front folding plate; 15. Front leak-proof baffle; 16. Left leak-proof baffle; 17. Right leak-proof baffle; 18. Box lid card; 19. Box lid card heat-sensitive adhesive; 20. Box body card. Detailed Implementation
[0021] Example 1
[0022] The leak-proof thermal adhesive paper box described in Example 1 is as follows: Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the device includes a cardboard box body 1 and a cardboard box lid 2 integrally connected to the cardboard box body. The inner walls of both the cardboard box body and the cardboard box lid are coated with a laminated paper. This leak-proof thermal adhesive cardboard box has an integral structure, ensuring the integrity of the entire box. The laminated paper provides waterproof and oil-proof protection for the inner walls of the thermal adhesive cardboard box, preventing water and grease from penetrating into the cardboard.
[0023] In this embodiment 1, the cardboard box includes a base plate 3, and a front side plate 4, a rear side plate 5, a left side plate 6, and a right side plate 7 that are connected to the base plate at the front, back, left, and right sides respectively and are of the same height. The four corners of the cardboard box are provided with leak-proof folding pieces 8 that are connected to the front side plate and the left side plate, the front side plate and the right side plate, the rear side plate and the left side plate, and the rear side plate and the right side plate respectively, forming an integral and uninterrupted leak-proof folding piece. The leak-proof folding piece is composed of two symmetrically arranged triangular folding pieces. The outer ends of the left side plate and the right side plate are provided with side plate heat-sensitive adhesive 9, and the outer side of the leak-proof folding piece facing the side plate heat-sensitive adhesive is provided with folding piece heat-sensitive adhesive 10 that forms a heat-sealed bond with the side plate heat-sensitive adhesive. The leak-proof folding flaps at four locations on the cardboard box form a two-layer structure composed of symmetrical triangular folding flaps. This ensures that adjacent side panels are not only connected without any gap (in traditional products, the ends of adjacent side panels are glued together but are disconnected, forming a gap, which is then sealed after gluing to form a seam). This prevents liquid from the food inside the cardboard box from leaking out from the connecting points between the corners of adjacent side panels. Even if liquid leaks into the gap between two triangular folding flaps, the triangular design of the leak-proof folding flaps will cause the leaked liquid to flow back into the cardboard box along the fold line, providing a secondary leak-proof effect and achieving a more comprehensive leak-proof effect, ensuring leak-proof quality. The outer ends of the cardboard box are coated with side panel heat-sensitive adhesive and the leak-proof folding flaps are coated with folding flap heat-sensitive adhesive. When forming the cardboard box using heat-sensitive adhesive, machine heat sealing is used. The heat-sensitive adhesive plays a role in heat sealing. Through the heat sealing effect of the heat-sensitive adhesive, the heat-sensitive adhesive becomes very sticky, thereby achieving a very strong bond between the leak-proof folding flaps and the cardboard box body. It has the advantages of strong adhesion and good high temperature resistance.
[0024] In this embodiment 1, the carton lid includes a lid plate 11 connected to the rear side panel, a left folding plate 12 and a right folding plate 13 on both sides of the lid plate that fold inward by 90 degrees, and a front folding plate 14 on the front end of the lid plate that folds inward by 90 degrees. The front end and left and right sides of the carton lid are provided with folding plates that fold downward by 90 degrees. When the carton lid is closed with the carton body, these folding plates will cover part of the front end and left and right sides of the carton body, providing a certain degree of wrapping effect on the top of the carton body, stabilizing the fit between the carton lid and the carton body, preventing displacement, and achieving the positioning function of the carton lid and carton body being closed.
[0025] In this embodiment 1, the front, left, and right side panels are respectively equipped with a front leak-proof baffle 15, a left leak-proof baffle 16, and a right leak-proof baffle 17, which are folded inward by 90 degrees to form a horizontal state. When the food loaded in the cardboard box is high, or when there is vibration during takeout transportation or uneven placement of the heat-sensitive adhesive cardboard box, liquid may leak out. The leak-proof baffles installed in the cardboard box can prevent liquids or sauces from overflowing or seeping out from the top edge of the cardboard box, thus blocking the liquids or sauces and improving the overall leak-proof effect of the heat-sensitive adhesive cardboard box.
[0026] In this embodiment 1, the two ends of the front folding plate of the box lid are provided with box lid clips 18 that fold inward at 90 degrees, such as... Figure 6 As shown; a heat-sensitive adhesive 19 is provided on the outer middle position of the lid card, which forms a heat-sealed bond with the inner sides of the left and right folding plates of the lid; a box body card 20 is provided on the top of the leak-proof folding piece at the connection position between the front side plate and the left side plate, and at the connection position between the front side plate and the right side plate; when the paper box lid and the paper box body are closed, the bottom of the box body card is inserted into the gap between the top of the lid card and the front folding plate of the lid to form a tight fixation. By setting a lid card on the front folding plate of the lid and using heat-sensitive adhesive on the lid card to achieve a heat-sealing and secure bonding with the left and right folding plates of the lid, the entire carton lid structure becomes stable and not easily detached. The box body card has a movable folding structure and does not stick firmly to the leak-proof folding plate, but is only integrated with the top of the leak-proof folding plate, that is, the folding line of the box body card is located at the top of the leak-proof folding plate. When the carton lid and the carton body are closed, the carton lid is slightly pulled upwards, at which point the top of the lid card will snap into the bottom of the folded box body card to form a tight lock. When it snaps into the heat-sensitive adhesive position of the lid card, it is locked in place. This creates a snap-locking effect between the carton lid and the carton body, solving the problem that traditional leak-proof carton products cannot be completely locked when closing to prevent leaks.
[0027] In this embodiment 1, the front, rear, left, and right side panels are all angled outwards to form a trapezoidal shape, wider at the top and narrower at the bottom, for the box body. The side panels of the box body are designed with a slightly outward-pointing shape, i.e., a trapezoidal structure. This allows sauces or liquids adhering to the side panels to flow back into the box body along the inner wall of the side panels, resulting in better leak-proof and spill-proof effects. This structure also slightly increases the loading capacity of the box body.
[0028] In this embodiment 1, the width of the lid card is smaller than the width of the front fold plate, the left fold plate, and the right fold plate of the lid. After the lid card is pasted and fixed to the left and right fold plates of the lid, the distance between the top of the lid card and the lid plate is smaller than the width of the box body card. With this width design, when the box lid and the box body are closed and locked, the top of the lid card can be smoothly inserted into the bottom of the folded box body card, and when the box lid is opened, the lid card can be easily separated from the box body card, thus achieving the purpose of opening the box lid.
[0029] In this embodiment 1, the height of the leak-proof folding piece is consistent with the height of the front, rear, left, and right side panels. This height setting of the leak-proof folding piece ensures that the leak-proof position is at the same height as the cardboard box body, solving the problem that traditional cardboard boxes cannot be completely leak-proof.
[0030] In this embodiment 1, the leak-proof heat-sensitive adhesive cardboard box addresses the problem that current market products lack full leak-proof performance and cannot meet the ever-changing new leak-proof requirements. It solves the problem that traditional heat-sealed cardboard boxes cannot achieve full leak-proof performance. This leak-proof heat-sensitive adhesive cardboard box features seamless leak-proof folds at each of the four corners, integrated with the box body. These folds are heat-sealed using heat-sensitive adhesive to ensure a firm bond at the corners, preventing liquid leakage and achieving a complete leak-proof effect. The adhesive strength remains unaffected by the high temperatures of food, eliminating any potential leakage. Furthermore, the lid and box body are locked together via a snap-fit mechanism, ensuring a secure fit. This not only allows the lid to close properly and maintains the box's appearance when opened, but also conceals the snap-fit structure, preserving an aesthetically pleasing look. It also solves the problem of traditional cardboard boxes only having two points of fixation between the front and rear ends and the box body. This heat-sensitive adhesive cardboard box's snap-fit structure provides three points of fixation—on the left, right, and rear sides—improving the stability and strength of the closed lid and box body.
[0031] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the structure of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.
Claims
1. A leak-proof thermal adhesive cardboard box, characterized in that, Includes a paper box body (1) and a paper box lid (2) that is integrally connected with the paper box body. The inner walls of the paper box body and the paper box lid are covered with coated paper. The paper box body includes a base plate (3), and a front side plate (4), a rear side plate (5), a left side plate (6), and a right side plate (7) that are connected to the base plate at the front, back, left, and right sides respectively and are of the same height. The four corners of the paper box body are provided with a leak-proof folding piece (8) that is connected to the front side plate and the left side plate, the front side plate and the right side plate, the rear side plate and the left side plate, and the rear side plate and the right side plate respectively, forming an integral and uninterrupted leak-proof folding piece. The leak-proof folding piece is composed of two symmetrically arranged triangular folding pieces. The outer ends of the left side plate and the right side plate are provided with side plate heat-sensitive adhesive (9), and the outer side of the leak-proof folding piece facing the side plate heat-sensitive adhesive is provided with a folding piece heat-sensitive adhesive (10) that forms a heat-sealed bond with the side plate heat-sensitive adhesive. The paper box lid includes a lid plate (11) connected to the rear side panel, a left folding plate (12) and a right folding plate (13) on both sides of the lid plate that are folded inward by 90 degrees, and a front folding plate (14) on the front end of the lid plate that is folded inward by 90 degrees.
2. The leak-proof thermal adhesive cardboard box according to claim 1, characterized in that, The front panel, left panel and right panel are respectively provided with a front leak-proof baffle (15), a left leak-proof baffle (16) and a right leak-proof baffle (17) that are folded inward by 90 degrees to form a horizontal state.
3. A leak-proof thermal adhesive cardboard box according to claim 2, characterized in that, The front folding plate of the box lid is provided with a box lid card (18) that folds inward at 90 degrees at both ends. The outer middle position of the box lid card is provided with a heat-sensitive adhesive (19) that forms a heat seal firmly with the inner side of the left folding plate and the right folding plate of the box lid. The top of the leak-proof folding piece at the connection position between the front side plate and the left side plate and the connection position between the front side plate and the right side plate is provided with a box body card (20) that folds downward. When the paper box lid and the paper box body are closed, the bottom of the box body card is inserted into the gap between the top of the box lid card and the front folding plate of the box lid to form a tight fixation.
4. A leak-proof thermal adhesive cardboard box according to claim 3, characterized in that, The front, rear, left, and right side panels are all angled outwards to form a trapezoidal shape that is wider at the top and narrower at the bottom of the cardboard box.
5. A leak-proof thermal adhesive cardboard box according to claim 4, characterized in that, The width of the box cover card is smaller than the width of the front fold plate, the left fold plate, and the right fold plate of the box cover; after the box cover card is pasted and fixed on the left fold plate and the right fold plate of the box cover, the distance between the top of the box cover card and the box cover plate is smaller than the width of the box body card.
6. A leak-proof thermal adhesive cardboard box according to claim 5, characterized in that, The height of the leak-proof folding panel is consistent with the height of the front panel, rear panel, left panel, and right panel.