High-strength anti-cracking single corrugated carton and manufacturing process thereof

Abstract

The invention relates to a high-strength anti-cracking single corrugated carton and a manufacturing process thereof, and relates to the technical field of logistics packaging, and the high-strength anti-cracking single corrugated carton comprises a carton body made of corrugated boards. The three-dimensional supporting network is formed through the asymmetric corrugation height arrangement and the staggered bonding nodes, when the box body is pressed, the corrugating medium paper with different corrugation heights can disperse pressure according to the difference of the stress direction, and the staggered bonding nodes construct a supporting framework in a three-dimensional space. According to the design, traditional plane stress is converted into three-dimensional stress, the overall compressive strength of the carton is remarkably improved, and the problem that a traditional single corrugated carton is prone to permanent deformation due to continuous stress is solved; after the self-locking type folding lining strip is embedded into the joint of the box body, the lining strip and the paperboard form a rigid supporting structure according to the prestressing force principle, it is ensured that when corners are impacted or extruded through the one-way bending characteristic of the lining strip, the lining strip absorbs energy through structural deformation of the lining strip, and meanwhile excessive bending of the paperboard is limited.

Description

Technical Field

[0001] This invention relates to the field of logistics packaging technology, and in particular to a high-strength, crack-resistant single-wall corrugated cardboard box and its manufacturing process. Background Technology

[0002] In the logistics packaging industry, single-wall corrugated cardboard boxes have become a commonly used packaging material in cargo transportation and storage due to their lightweight and low cost. They are especially frequently used in long-distance transportation and stacked storage scenarios. However, traditional single-wall corrugated cardboard boxes have many drawbacks in practical applications. Under continuous pressure, the box body is prone to permanent deformation, and micro-cracks easily propagate from the corners. This not only significantly reduces the number of times the box can be reused, but also increases logistics costs due to frequent box replacements. Furthermore, damage to the box can lead to cargo loss. It fails to meet the stringent requirements of modern logistics for packaging materials in terms of high strength, crack resistance, and high recyclability. Therefore, there is an urgent need to improve the structure and manufacturing process of single-wall corrugated cardboard boxes. This paper presents a high-strength, crack-resistant single-wall corrugated cardboard box and its manufacturing process. Summary of the Invention

[0003] 1. Technical problems to be solved The purpose of this application is to provide a high-strength, crack-resistant single-wall corrugated cardboard box and its manufacturing process to solve the problems in the prior art.

[0004] This application provides a high-strength, crack-resistant single-wall corrugated cardboard box with the following technical solution: It includes a box body made of corrugated cardboard, which comprises sequentially laminated face paper, corrugated core paper, and liner paper. The box body adopts a variable-density corrugated waveform design, forming a three-dimensional support network through asymmetrical flute height arrangement and staggered bonding nodes. Self-locking folding strips are embedded at the seams of the box body. These self-locking folding strips utilize prestressing principles to strengthen the corner structure rigidity and maintain unidirectional bending characteristics. The surface of the corrugated core paper is coated with a high-penetration adhesive coating, forming a continuous reinforcing interface at the flute peaks and valleys. Microencapsulated repair agents are injected into the corrugated core paper interlayer. These microencapsulated repair agents rupture and release when the cardboard fibers are compressed and broken, serving as self-repair agents for cracks. The corners of the box body employ a serpentine folding reinforcement process, pre-folding a certain width area at the box panel seams into a sinusoidal wave structure, and then curing with water-based polyurethane adhesive to form an elastic buffer zone. All these structures work together to enhance the box's compression and crack resistance. By adopting the above technical solutions, through variable-density corrugated waveform design, and utilizing asymmetrical flute height arrangement and staggered bonding nodes to form a three-dimensional support network, the traditional planar stress pattern of cardboard boxes is changed, enabling the box to evenly distribute pressure when compressed, significantly improving its compression resistance. Self-locking folding strips are embedded in the seams, strengthening the corner stiffness based on the prestress principle. Their unidirectional bending characteristics limit excessive deformation under stress, effectively preventing corner cracking. A highly permeable adhesive coating, applied to the surface of the corrugated core paper, penetrates into the fiber gaps, enhancing the bonding force between the face paper, corrugated core paper, and liner paper, preventing interlayer peeling. Microencapsulated repair agents are released and react when the cardboard fibers break, automatically repairing cracks and extending the box's lifespan. A serpentine folding reinforcement process, combined with a sinusoidal corrugated structure and water-based polyurethane adhesive, forms an elastic buffer zone at the corners of the box, absorbing impact energy and reducing damage. The synergistic effect of these structures improves the performance of the cardboard box in terms of compression resistance, crack resistance, self-repair, and cushioning, solving the problems of deformation and cracking in traditional single-wall corrugated cardboard boxes.

[0005] Preferably, in the variable density corrugated waveform design, the arrangement of asymmetrical corrugation heights is differentiated according to the stress conditions of different parts of the box. By adopting the above technical solutions and making differentiated settings according to the stress conditions of different parts of the box, the support structure can be precisely optimized to address the stress differences in different parts of the box (such as the bottom and sides) during actual use. For example, the bottom of the box bears a large pressure from the weight of the goods, so a higher flute height and denser adhesive joints can be set, while the sides are mainly subjected to lateral compression, so an appropriate flute height distribution can be adjusted. This allows the corrugated cardboard to exert its optimal mechanical properties in each part, further improving its compressive strength and structural stability. Compared with a uniform flute height design, material utilization is more rational and performance improvement is more significant.

[0006] Preferably, the self-locking folding strip is made of high-strength plastic with a certain degree of elasticity; By adopting the above technical solution, the self-locking folding strip is made of high-strength plastic material with a certain degree of elasticity. The high strength ensures that the strip can withstand greater external forces, effectively supporting the corners of the box and preventing deformation; the certain elasticity allows it to deform appropriately under force to absorb energy, avoiding stress concentration that could lead to strip breakage or cardboard damage. At the same time, the elastic material facilitates the bending and embedding of the strip and maintains unidirectional bending characteristics, enhancing its compatibility with cardboard. Compared with ordinary rigid materials, it not only ensures reinforcement but also improves reliability and durability.

[0007] Preferably, the highly permeable adhesive coating is able to penetrate into the fiber gaps of the corrugated core paper; By adopting the above technical solution, the highly permeable adhesive coating can penetrate into the fiber gaps of the corrugated core paper, allowing the adhesive to fully fill the fiber pores and form a continuous and strong reinforcing interface at the corrugation peaks and valleys. This characteristic breaks through the limitation of traditional coatings that only adhere to the surface, enabling the linerboard, corrugated core paper, and linerboard to form a tightly bonded whole through the adhesive, significantly improving interlayer bonding strength, effectively resisting delamination caused by external forces, thereby enhancing the overall strength and tear resistance of the corrugated board, and ensuring the structural integrity of the carton during transportation and use.

[0008] Preferably, the microencapsulated repair agent is composed of two components that can react to achieve the repair function: epoxy resin and curing agent. The epoxy resin is encapsulated in the microcapsule, and the curing agent is dispersed between the fibers of the corrugated core paper interlayer. When the paperboard fibers are squeezed and broken, the microcapsule breaks and releases the epoxy resin, which reacts with the curing agent to fill and cure the crack. By adopting the above technical solution, the microencapsulated repair agent consists of two components that can react to achieve a repair function. When the cardboard fibers are compressed and broken, the microcapsules rupture, the two components mix and rapidly undergo a chemical reaction, filling and solidifying the cracks to achieve self-repair. This design requires no manual intervention, can repair cracks in their early stages, prevent further expansion, significantly extend the service life of the carton, reduce the frequency of carton replacement due to damage, lower logistics packaging costs, and improve the safety of packaged goods. Compared with cartons without self-repair function, it has higher practicality and economy.

[0009] Preferably, the shape parameters of the sinusoidal corrugated structure are adjusted according to the size of the carton and the usage scenario; By adopting the above technical solution, the shape parameters of the sinusoidal corrugated structure can be adjusted according to the size of the carton and the usage scenario. For large cartons, the corrugation wavelength and height can be increased to enhance the cushioning effect and adapt to the impact of heavy goods. For small cartons or scenarios with high space requirements, the corrugation parameters are optimized to reduce the space occupied by materials while ensuring cushioning performance. This flexible adjustment method allows the serpentine folding reinforcement process to adapt to diverse packaging needs, ensuring that the corners of the carton receive optimal impact protection under different sizes and usage conditions, thereby improving the versatility and applicability of the carton.

[0010] Preferably, the waterborne polyurethane adhesive has good flexibility and adhesion after curing; By adopting the above technical solution, the waterborne polyurethane adhesive exhibits excellent flexibility and adhesion after curing. Its flexibility prevents it from failing due to brittle fracture when the sinusoidal corrugated structure is subjected to stress deformation, thus continuously buffering stress and ensuring the effectiveness of the elastic cushioning strip. The excellent adhesion ensures a tight bond between the adhesive and the cardboard, providing a stable connection between the sinusoidal corrugated structure and the box body, preventing the cushioning structure from detaching. Compared to ordinary adhesives, this waterborne polyurethane adhesive, while ensuring bonding strength, imparts excellent dynamic mechanical properties to the cushioning strip, effectively improving the ability of the carton's edges and corners to resist repeated impacts and bending, and extending the carton's service life.

[0011] A manufacturing process for a high-strength, tear-resistant single-wall corrugated cardboard box includes the following steps: S1: According to the design requirements, a cardboard with variable density corrugated waveform is produced. A three-dimensional support network is formed by controlling the arrangement of flute heights and the staggered bonding nodes. First, the face paper, corrugated paper, and liner paper are selected. High-precision corrugating forming equipment is used to process the corrugated paper into corrugated core paper. According to the stress analysis data of different parts of the box, the flute height variation parameters are adjusted during the corrugated core paper forming process so that the asymmetrical flute heights are arranged according to the predetermined rules. At the same time, the bonding node positions of adjacent corrugations are set, and adhesive is applied to the nodes by a glue roller. S2: Coat the surface of the corrugated core paper with a high-penetration adhesive coating; select a suitable coating method to evenly coat the surface of the corrugated core paper with the high-penetration adhesive, and then laminate the coated corrugated core paper with the face paper and the liner paper to form variable density corrugated corrugated cardboard. S3: Embed self-locking folding strips at the seams of the prepared cardboard; first, cut the sheet material for making the self-locking folding strips and pre-form it into a shape with a self-locking structure. Then, at the seam of the cardboard, embed the self-locking folding strips into the edge of the cardboard using an embedding device. At the same time, use adhesive to bond and fix the self-locking folding strips to the contact area of ​​the cardboard, ensuring that the self-locking folding strips are firmly fixed and maintain unidirectional bending characteristics. S4: Inject microencapsulated repair agent into the corrugated core paper interlayer; using injection equipment, inject the microencapsulated repair agent into the corrugated core paper interlayer through a needle to ensure that the microencapsulated repair agent is evenly distributed in the interlayer, and after injection, treat it to make the microencapsulated repair agent better bond with the paperboard; S5: The corners of the box are reinforced by serpentine folding. A certain width of the seam between the box panels is folded into a sinusoidal wave structure and cured with water-based polyurethane adhesive. First, a certain width of the seam between the box panels is folded into a sinusoidal wave structure using a special folding device. Then, water-based polyurethane adhesive is evenly sprayed onto the folded area using a spraying device. After spraying, the corners of the carton are placed in a curing device to allow the water-based polyurethane adhesive to fully cure, forming a cushioning band with high elasticity and folding resistance, thus completing the carton production.

[0012] 2. Beneficial effects In summary, this application includes at least one of the following beneficial technical effects: 1. This invention provides a high-strength, crack-resistant single-wall corrugated cardboard box and its manufacturing process. A three-dimensional support network is formed through asymmetrical flute height arrangement and staggered bonding nodes. When the box is under pressure, the corrugated core paper with different flute heights can distribute pressure differently according to the direction of force, while the staggered bonding nodes construct a support skeleton in three-dimensional space. This design transforms traditional planar force application into three-dimensional force application, significantly improving the overall compressive strength of the cardboard box and solving the problem of permanent deformation easily caused by continuous pressure on traditional single-wall corrugated cardboard boxes. After the self-locking folding strip is embedded at the box seam, the prestressing principle is used to form a rigid support structure between the strip and the cardboard. Its unidirectional bending characteristic ensures that when the corners are impacted or squeezed, the strip absorbs energy through its own structural deformation, while limiting excessive bending of the cardboard. This structure directly strengthens the weak corners of the cardboard box, effectively inhibiting the propagation of micro-cracks at the corners, improving the impact resistance of the cardboard box, and extending the number of cycles. A highly permeable adhesive coating is applied to the surface of the corrugated core paper and penetrates into the fiber gaps, forming a continuous reinforcing interface at the corrugation peaks and valleys. This interface tightly bonds the face paper, corrugated core paper, and liner paper into a whole, enhancing the bonding strength between the layers and avoiding structural failure caused by interlayer peeling in traditional cardboard, thereby improving the carton's resistance to deformation and cracking.

[0013] 2. This invention provides a high-strength, crack-resistant single-wall corrugated cardboard box and its manufacturing process. By injecting a microencapsulated repair agent into the corrugated core paper interlayer, when the cardboard fibers are compressed and cracked, the microcapsules simultaneously rupture, releasing two reactive components that quickly fill the cracks and solidify. This mechanism achieves self-repair of cardboard cracks, preventing crack propagation without manual intervention. It solves the problem of needing to replace the entire box after damage, thus reducing logistics packaging costs.

[0014] 3. This invention provides a high-strength, crack-resistant single-wall corrugated cardboard box and its manufacturing process. The seams of the box panels are folded into a sinusoidal corrugated structure, which, after curing with a water-based polyurethane adhesive, forms an elastic buffer zone. When the corners of the cardboard box are impacted or squeezed, the sinusoidal corrugated structure absorbs the impact energy through deformation, while the flexibility of the water-based polyurethane adhesive buffers stress concentration. The synergistic effect of both gives the corners folding resistance and elastic recovery capability, effectively reducing corner cracks and improving packaging reliability. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention. Figure 2 This is a schematic diagram of the asymmetric rib height arrangement of the present invention; Figure 3 This is a schematic diagram of the structure of the self-locking folding liner of the present invention; Figure 4 This is a partial cross-sectional structural schematic diagram of the corrugated cardboard of the present invention; Figure 5 This is a diagram showing the structural composition and hierarchical relationship of the cardboard box of the present invention; Figure 6 This is a step-by-step flowchart of the manufacturing process of this invention; Figure 7 This is a logic diagram illustrating the synergistic effect of performance enhancement in this invention.

[0016] The components include: 1. Box body; 2. Corrugated cardboard; 201. Face paper; 202. Corrugated core paper; 203. Liner paper; 3. Variable density corrugated waveform design; 4. Self-locking folding strips; 5. High-penetration adhesive coating; 6. Microencapsulated repair agent; 7. Serpentine folding reinforcement process; 8. Sine wave structure; 9. Water-based polyurethane adhesive. Detailed Implementation

[0017] The following is in conjunction with the appendix Figure 1 -Appendix Figure 7 This application will be described in further detail below.

[0018] Example 1: A high-strength, crack-resistant single-wall corrugated cardboard box, referring to... Figure 2 , Figure 4 and Figure 5The box body 1 is made of corrugated cardboard 2, which comprises a face paper 201, a corrugated core paper 202, and a liner paper 203 laminated sequentially. The box body 1 adopts a variable density corrugated waveform design 3, forming a three-dimensional support network through asymmetrical flute height arrangement and staggered bonding nodes. Self-locking folding strips 4 are embedded at the seams of the box body 1. The self-locking folding strips 4 utilize the prestress principle to strengthen the rigidity of the corner structure and maintain unidirectional bending characteristics. The surface of the corrugated core paper 202 is coated with a high-penetration adhesive coating 5, forming a continuous reinforcing interface at the corrugated peaks and valleys. Microencapsulated repair agent 6 is injected into the interlayer of the corrugated core paper 202. The microencapsulated repair agent 6 is released when the cardboard fibers are squeezed and broken, and is used for self-repair of cracks. The corners of the box body 1 adopt a serpentine folding reinforcement process 7, pre-folding a certain width area at the seam of the box body into a sinusoidal wave structure 8, and curing it with water-based polyurethane adhesive 9 to form an elastic buffer zone. All structures cooperate with each other. Together, these technologies enhance the compression and crack resistance of the carton. A variable-density corrugated waveform design 3 utilizes an asymmetrical flute height arrangement and staggered bonding nodes to form a three-dimensional support network, altering the traditional planar stress pattern of the carton. This allows the carton body 1 to distribute pressure evenly under pressure, significantly improving its compression resistance. Self-locking folding strips 4 are embedded at the seams, strengthening corner stiffness based on prestressing principles. Their unidirectional bending characteristics limit excessive deformation under stress, effectively preventing corner cracking. A highly permeable adhesive coating 5, applied to the surface of the corrugated core paper 202, penetrates into the fiber gaps, enhancing the bond between the face paper 201, corrugated core paper 202, and liner paper 203, preventing interlayer peeling. A microencapsulated repair agent 6 is released and reacts when the cardboard fibers break, automatically repairing cracks and extending the carton's lifespan. A serpentine folding reinforcement process 7, combined with a sinusoidal corrugated structure 8 and water-based polyurethane adhesive 9, forms an elastic buffer zone at the corners of the carton body 1, absorbing impact energy and reducing damage. The various structures work together to improve the performance of the carton in terms of compression resistance, crack resistance, self-repair, and cushioning, thus solving the problems of deformation and cracking of traditional single-wall corrugated cartons.

[0019] Reference Figure 1 , Figure 3 and Figure 7In the variable density corrugated waveform design 3, the asymmetrical flute height arrangement is differentiated according to the stress conditions of different parts of the box 1. The self-locking folding strip 4 is made of high-strength and elastic plastic. This differentiated arrangement, based on the stress conditions of different parts of the box 1, allows for precise optimization of the support structure to address the stress differences in different parts of the box 1 during actual use (such as the bottom and sides). For example, the bottom of the box 1 bears significant pressure from the weight of the goods, so a higher flute height and denser adhesive joints can be used. The sides, primarily subjected to lateral compression, are adjusted to a suitable flute height distribution, ensuring the corrugated cardboard 2 exhibits optimal mechanical properties in each part, further improving its compressive strength and structural stability. Compared to a uniform flute height design, this approach utilizes materials more efficiently and significantly enhances performance. The self-locking folding strip 4 is made of high-strength and elastic plastic. Its high strength ensures the strip can withstand significant external forces, effectively supporting the corners of the box 1 and preventing deformation. Its elasticity allows for moderate deformation to absorb energy under stress, preventing stress concentration that could lead to strip breakage or cardboard damage. Meanwhile, the elastic material facilitates the bending and embedding of the liner strips and maintains unidirectional bending characteristics, enhancing its compatibility with cardboard. Compared with ordinary rigid materials, it not only ensures the reinforcement effect but also improves the reliability and durability of use.

[0020] Reference Figure 1 , Figure 4 and Figure 5The highly permeable adhesive coating 5 can penetrate into the fiber gaps of the corrugated core paper 202. The microencapsulated repair agent 6 consists of two components that can react to achieve the repair function: epoxy resin and curing agent. The epoxy resin is encapsulated in microcapsules, and the curing agent is dispersed between the interlayer fibers of the corrugated core paper 202. When the paperboard fibers are squeezed and broken, the microcapsules break and release the epoxy resin, which reacts with the curing agent to fill and cure the cracks. The highly permeable adhesive coating 5 can penetrate into the fiber gaps of the corrugated core paper 202, allowing the adhesive to fully fill the fiber pores and form a continuous and strong reinforcing interface at the corrugated peaks and valleys. This feature breaks through the limitation of traditional coatings that only adhere to the surface, allowing the face paper 201, corrugated core paper 202, and liner paper 203 to form a tightly bonded whole through adhesive. This significantly improves interlayer bonding strength, effectively resists delamination caused by external forces, and thus enhances the overall strength and tear resistance of the corrugated cardboard 2, ensuring the structural integrity of the carton during transportation and use. The microencapsulated repair agent 6 consists of two components that can react to achieve a repair function. When the cardboard fibers are compressed and broken, the microcapsules rupture, the two components mix and rapidly undergo a chemical reaction, filling and solidifying the cracks to achieve self-repair. This design requires no manual intervention, can repair cracks in their early stages, prevent further expansion, significantly extend the service life of the carton, reduce the frequency of carton replacement due to damage, lower logistics packaging costs, and also improve the safety of packaged goods. Compared with cartons without self-repair function, it has higher practicality and economy.

[0021] Reference Figure 1 , Figure 5 and Figure 7The shape parameters of the sinusoidal corrugated structure 8 are adjusted according to the size of the carton and the usage scenario. The water-based polyurethane adhesive 9, after curing, has good flexibility and adhesion. For large cartons, the corrugation wavelength and height can be increased to enhance the cushioning effect and adapt to the impact of heavier goods. For small cartons or scenarios with high space requirements, the corrugation parameters are optimized to reduce material space occupation while ensuring cushioning performance. This flexible adjustment method allows the serpentine folding reinforcement process 7 to adapt to diverse packaging needs, ensuring that the corners of the carton 1 receive optimal impact protection under different sizes and usage conditions, improving the versatility and applicability of the carton. The water-based polyurethane adhesive 9, after curing, has good flexibility and adhesion. Its flexibility prevents it from failing due to brittle fracture when the sinusoidal corrugated structure 8 is deformed under stress, allowing for continuous stress cushioning and ensuring the effectiveness of the elastic cushioning band. Good adhesion ensures a tight bond between the adhesive and the cardboard, making the sinusoidal corrugated structure 8 firmly connected to the carton 1 and preventing the cushioning structure from detaching. Compared to ordinary adhesives, this water-based polyurethane adhesive 9, while ensuring bonding strength, imparts excellent dynamic mechanical properties to the cushioning strip, effectively improving the ability of the carton's edges and corners to resist repeated impacts and bending, and extending the carton's service life.

[0022] This application also discloses a manufacturing process for a high-strength, crack-resistant single-wall corrugated cardboard box, which is applicable to one of the high-strength, crack-resistant single-wall corrugated cardboard boxes mentioned above. The construction steps are as follows: S1: According to the design requirements, a cardboard with variable density corrugated waveform is made. A three-dimensional support network is formed by controlling the arrangement of flute heights and the interlacing of adhesive nodes. First, the face paper 201, corrugated paper and liner paper 203 are selected. The corrugated paper is processed into corrugated core paper 202 using a high-precision corrugated forming equipment. According to the stress analysis data of different parts of the box body 1, the flute height variation parameters are adjusted during the corrugated core paper 202 forming process so that the asymmetrical flute heights are arranged according to the predetermined law. At the same time, the adhesive node positions of adjacent corrugations are set, and adhesive is applied to the nodes by a glue roller. S2: Coat the surface of the corrugated core paper 202 with a high-penetration adhesive coating 5; select a suitable coating method to evenly coat the surface of the corrugated core paper 202 with the high-penetration adhesive, and then composite the coated corrugated core paper 202 with the face paper 201 and the inner paper 203 to form a variable density corrugated corrugated cardboard. S3: Embed the self-locking folding strip 4 at the seam of the prepared cardboard; first, cut the sheet material for making the self-locking folding strip 4 and pre-form it into a shape with a self-locking structure. Then, at the seam of the cardboard, embed the self-locking folding strip 4 into the edge of the cardboard using an embedding device. At the same time, use adhesive to bond and fix the self-locking folding strip 4 to the contact area of ​​the cardboard, ensuring that the self-locking folding strip 4 is firmly fixed and maintains its unidirectional bending characteristics. S4: Inject microencapsulated repair agent 6 into the corrugated core paper 202 interlayer; using an injection device, inject the microencapsulated repair agent 6 into the corrugated core paper 202 interlayer through a needle, ensuring that the microencapsulated repair agent 6 is evenly distributed in the interlayer, and after injection, treat it to make the microencapsulated repair agent 6 better bond with the paperboard; S5: The corners of the box body 1 are reinforced by serpentine folding. A certain width of the seam of the box panels is folded into a sinusoidal wave structure 8 and cured with water-based polyurethane adhesive 9. First, a certain width of the seam of the box panels is folded into a sinusoidal wave structure 8 using a special folding device. Then, water-based polyurethane adhesive 9 is evenly sprayed onto the folded area using a spraying device. After spraying, the corners of the carton are placed in a curing device to allow the water-based polyurethane adhesive 9 to fully cure, forming a cushioning band with high elasticity and folding resistance, thus completing the carton production.

[0023] The implementation principle of this application embodiment is as follows: Based on the stress conditions of different parts of the box body 1, an asymmetrical arrangement of flute heights and staggered bonding nodes are adopted. Under pressure, the corrugated core paper 202 with different flute heights can specifically disperse the pressure. The staggered bonding nodes construct a three-dimensional support network, changing the traditional planar stress pattern of the carton and uniformly transmitting pressure to the entire structure of the box body 1, effectively improving its compressive strength. The self-locking folding strip 4 is made of high-strength and elastic plastic. After being embedded in the seams of the box body 1, it forms rigid support at the corners using the principle of prestress. When subjected to external impact or compression, the unidirectional bending characteristic of the strip allows it to absorb energy through its own structural deformation, while limiting excessive bending of the cardboard, strengthening the rigidity of the corner structure, and preventing cracks or damage at the corners. After the high-penetration adhesive coating 5 is applied to the surface of the corrugated core paper 202, it penetrates into the fiber gaps due to its high permeability, forming a continuous reinforcing interface at the corrugated peaks and valleys. This interface tightly connects the face paper 201, corrugated core paper 202, and liner paper 203, enhancing the bonding force between layers, preventing interlayer delamination under stress, and improving overall structural stability. Microencapsulated repair agent 6, composed of two reactive components, is injected into the corrugated core paper 202 interlayer. When the paperboard fibers break due to compression, the microcapsules also rupture, releasing their internal components and reacting to quickly fill and repair cracks, achieving the paperboard's self-healing function and extending the carton's lifespan. A serpentine folding reinforcement process 7 folds the seams of the carton into a sinusoidal corrugated structure 8, which is then cured with water-based polyurethane adhesive 9. When the carton's corners are impacted or squeezed, the sinusoidal corrugated structure 8 absorbs impact energy through elastic deformation. The good flexibility and adhesion of the cured water-based polyurethane adhesive 9 further buffer stress concentration, reducing damage to the corners and forming an elastic buffer zone with excellent folding resistance.

[0024] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-strength, crack-resistant single-wall corrugated cardboard box, comprising a box body (1) made of corrugated cardboard (2), characterized in that: The corrugated cardboard (2) comprises a face paper (201), a corrugated core paper (202), and a liner paper (203) sequentially laminated. The box body (1) adopts a variable density corrugated waveform design (3), forming a three-dimensional support network through asymmetrical flute height arrangement and staggered bonding nodes. Self-locking folding strips (4) are embedded at the seams of the box body (1). The self-locking folding strips (4) utilize the prestress principle to strengthen the rigidity of the corner structure and maintain unidirectional bending characteristics. The surface of the corrugated core paper (202) is coated with a high-penetration adhesive coating (5). A continuous reinforcing interface is formed at the peak and valley of the corrugated core paper (202). Microencapsulated repair agent (6) is injected into the interlayer of the corrugated core paper (202). The microencapsulated repair agent (6) is released when the paperboard fiber is squeezed and broken, and is used for self-repair of cracks. The corners of the box body (1) adopt a serpentine folding reinforcement process (7), and a certain width area at the joint of the box board is pre-folded into a sinusoidal wave structure (8), and is cured with water-based polyurethane adhesive (9) to form an elastic buffer band. The various structures cooperate with each other to improve the compression resistance and crack resistance of the carton.

2. A high-strength, crack-resistant single-wall corrugated cardboard box according to claim 1, characterized in that: In the variable density corrugated waveform design (3), the arrangement of asymmetric corrugation heights is differentiated according to the stress conditions of different parts of the box (1).

3. A high-strength, crack-resistant single-wall corrugated cardboard box according to claim 1, characterized in that: The self-locking folding strip (4) is made of high-strength plastic with a certain degree of elasticity.

4. A high-strength, crack-resistant single-wall corrugated cardboard box according to claim 1, characterized in that: The highly permeable adhesive coating (5) can penetrate into the fiber gaps of the corrugated core paper (202).

5. A high-strength, crack-resistant single-wall corrugated cardboard box according to claim 1, characterized in that: The microencapsulated repair agent (6) is composed of two components, epoxy resin and curing agent, which can react to achieve the repair function. The epoxy resin is encapsulated in the microcapsule, and the curing agent is dispersed between the interlayer fibers of the corrugated core paper (202). When the paperboard fibers are squeezed and broken, the microcapsule breaks and releases the epoxy resin, which comes into contact with the curing agent and undergoes a polymerization reaction to fill and cure the crack.

6. A high-strength, crack-resistant single-wall corrugated cardboard box according to claim 1, characterized in that: The shape parameters of the sinusoidal wave structure (8) are adjusted according to the size of the carton and the usage scenario.

7. A high-strength, crack-resistant single-wall corrugated cardboard box according to claim 1, characterized in that: The waterborne polyurethane adhesive (9) has good flexibility and adhesion after curing.

8. The manufacturing process of a high-strength, crack-resistant single-wall corrugated cardboard box according to any one of claims 1-7, characterized in that, Includes the following steps: S1: According to the design requirements, a cardboard with variable density corrugated waveform is made. A three-dimensional support network is formed by controlling the arrangement of flute height and the interlacing of adhesive nodes. First, the face paper (201), corrugated paper and liner paper (203) are selected. The corrugated paper is processed into corrugated core paper (202) using a high-precision corrugated forming equipment. According to the stress analysis data of different parts of the box (1), the flute height variation parameters are adjusted during the corrugated core paper (202) forming process so that the asymmetrical flute height is arranged according to the predetermined law. At the same time, the adhesive node positions of adjacent corrugations are set, and adhesive is applied to the nodes by the glue roller. S2: Coat the surface of the corrugated core paper (202) with a high-penetration adhesive coating (5); select a suitable coating method to uniformly coat the high-penetration adhesive on the surface of the corrugated core paper (202), and then combine the coated corrugated core paper (202) with the face paper (201) and the inner paper (203) to form a variable density corrugated corrugated cardboard. S3: Embed the self-locking folding strip (4) at the seam of the prepared cardboard; First, cut the sheet material for making the self-locking folding strip (4) and pre-form it into a shape with a self-locking structure. Then, at the seam of the cardboard, embed the self-locking folding strip (4) into the edge of the cardboard using an embedding device. At the same time, use adhesive to bond and fix the self-locking folding strip (4) to the contact area of ​​the cardboard to ensure that the self-locking folding strip (4) is firmly fixed and maintains the unidirectional bending characteristic. S4: Inject microencapsulated repair agent (6) into the interlayer of corrugated core paper (202); Using an injection device, inject the microencapsulated repair agent (6) into the interlayer of corrugated core paper (202) through a needle to ensure that the microencapsulated repair agent (6) is evenly distributed in the interlayer. After injection, the microencapsulated repair agent (6) is treated to better bond with the paperboard. S5: The corners of the box body (1) are reinforced by serpentine folding. A certain width of the box panel seam is folded into a sinusoidal wave structure (8), and then cured with water-based polyurethane adhesive (9). First, a certain width of the box panel seam is folded into a sinusoidal wave structure (8) using a special folding device. Then, water-based polyurethane adhesive (9) is evenly sprayed on the folded area using a spraying device. After spraying, the corners of the carton are placed in a curing device to allow the water-based polyurethane adhesive (9) to fully cure, forming a buffer zone with high elasticity and folding resistance, thus completing the carton production.

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