Hot press forming die set for preparing paper bowl with bottom rib structure

Abstract

The utility model discloses a hot press forming die set for preparing a paper bowl with a bottom rib structure, relates to a disposable container, and aims to solve the technical problems that the paper bowl is easy to tear and damage and difficult to form in the combined processing process. The key points of the technical scheme are as follows: a hot-press forming mold group comprises a pre-pressing mold for pre-pressing to form an edge rib and a hot forming mold for hot-press shaping; the thermal forming die comprises a bottom die and an upper die, the bottom die is provided with a shaping cavity matched with the outer surface of the paper bowl, the upper die is provided with a forming die head matched with the inner surface of the paper bowl, the bottom die is provided with a heating cavity around the shaping cavity, and the heating cavity is provided with a heating coil. The utility model aims to provide a hot-press forming die set for preparing a paper bowl with a bottom rib structure.

Description

Technical Field

[0001] This utility model relates to disposable containers, and more specifically, to a thermoforming mold assembly for preparing paper bowls with a bottom rib structure. Background Technology

[0002] Composite paper is a type of paper that has been laminated on one or both sides of the base paper. It is widely used in food or beverage packaging containers. Molding is a process route for preparing containers from laminated paper.

[0003] Regarding molded paper containers, Chinese Patent Announcement No. CN211663630U describes a paper container whose key technical features are: it includes a container wall and a container bottom, the lower end of the container wall is connected to the container bottom, the upper end of the container wall forms a container opening, the container opening has a rolled edge, the container wall has molded reinforcing ribs; the container opening has a rolled edge, and the container bottom is set as a recessed bottom.

[0004] The above technical solution improves structural strength by adding reinforcing ribs to the container wall. However, in actual tests, it was found that when designing paper containers with larger bottom walls, the bottom wall bears the greatest internal pressure and has higher strength requirements than the side walls. In other words, the existing paper bowls have the potential for deformation due to limited stress on the bottom wall. Therefore, a new solution is needed to address this problem. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a paper bowl with a bottom rib structure, which can improve the structural strength of the bottom wall, has better overall aesthetics, requires less flatness of the table surface, and is more conducive to gripping by automated production lines.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a paper bowl with a bottom rib structure, comprising a single sheet of composite paper that has been molded and shaped, wherein the composite paper has a side wall and a bottom wall after being molded and shaped, the side wall is integrally molded to form a side rib, and the bottom wall is integrally molded to form an annular bottom rib, wherein the annular bottom rib is concentrically arranged with the vertical central axis of the bottom wall.

[0007] By adopting the above technical solution and using composite paper hot pressing and shaping, compared with the bending and bonding of existing technologies, it has the advantages of high production efficiency and low production cost. In addition to setting the edge ribs, the bottom ribs can be set to improve the structural strength of the bottom wall, meet the design requirements of larger bottom wall containers, and improve the three-dimensionality of the product, effectively improving the overall aesthetics. Moreover, compared with the flat bottom structure of existing technologies, the flatness requirement of the placement platform is lower. It should be noted that due to the presence of the bottom ribs, when multiple applications are stacked, there is a larger gap between adjacent ones, which is more conducive to the gripping of automated production lines.

[0008] The present invention is further configured such that: the composite paper includes a base paper layer and a functional layer, wherein the functional layer is one or more of the following: a PP coating layer, a PET coating layer, a PE coating layer, a PLA coating layer, a PBS coating layer, or a plastic-free coating layer.

[0009] The present invention is further configured such that: the overall weight of the composite paper is 130g-300g, and the overall thickness of the composite paper is 0.2-0.5mm.

[0010] The present invention is further configured such that the opening end of the side wall is provided with an outwardly turned edge.

[0011] The present invention is further configured such that an arc transition edge is provided between the side wall and the bottom wall.

[0012] The present invention is further configured such that: the side reinforcement includes long side reinforcement and short side reinforcement, the long side reinforcement and short side reinforcement are alternately arranged, the bottom end of the long side reinforcement extends to the annular bottom reinforcement, and the bottom end of the short side reinforcement extends to the arc transition edge.

[0013] The present invention is further configured such that: the bottom wall is integrally molded to form a central boss, and the central boss and the annular bottom rib are concentrically arranged.

[0014] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a paper bowl hot pressing molding die assembly, which pre-presses the composite paper to prevent tearing and damage, and ensures the molding of the paper bowl by heating.

[0015] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a paper bowl hot pressing forming mold assembly for preparing the above-mentioned paper bowl, including a pre-pressing mold for pre-pressing to form edge ribs, and a hot pressing forming mold for hot pressing and shaping; the hot pressing forming mold includes a bottom mold and an upper mold, the bottom mold has a shaping cavity that matches the outer surface of the paper bowl, the upper mold has a forming die head that matches the inner surface of the paper bowl, the bottom mold has a heating cavity arranged around the shaping cavity, and the heating cavity is provided with a heating coil.

[0016] By adopting the above technical solution, the composite paper is first pre-pressed using a pre-pressing mold to pre-form creases on the edge ribs. This ensures that the thermoforming mold will not cause tearing or breakage when it forces the composite paper to undergo significant deformation. Specifically, the creases on the edge ribs are used to compensate for the diameter difference in different areas of the composite paper, ensuring that the shaping chamber and the forming die work together to thermo-press and produce a paper bowl with bottom ribs. Furthermore, the shaping chamber is heated by a heating coil through the heating chamber, thereby achieving thermo-press forming of the paper bowl with bottom ribs. In summary, pre-pressing the composite paper prevents tearing and breakage, and heating ensures the molding of the paper bowl.

[0017] The present invention is further configured such that a lifting fixture is vertically connected to the center of the bottom mold.

[0018] The present invention is further configured such that: the upper mold is slidably connected to multiple optical axes, the bottom end of the optical axes is fixed with a pressing fixture, the pressing fixture is gap-fitted to the forming die head, and multiple compression springs are provided between the pressing fixture and the upper mold.

[0019] In summary, the present invention has the following beneficial effects: 1. The bottom rib 4 can improve the structural strength of the bottom wall and meet the design requirements of larger bottom wall containers.

[0020] 2. Multiple functional layers can adapt to different scenario requirements.

[0021] 3. The outward-curving edge 7 enhances the structural strength of the open end, preventing curling or tearing, while providing hand comfort and reducing the risk of burns.

[0022] 4. The rounded transition along the 8th line eliminates the right-angle connection between the side wall 1 and the bottom wall 2, reducing stress concentration and preventing cracking during folding or compression.

[0023] 5. The alternating layout of long and short side reinforcements forms a gradient support, which synergistically improves the overall compressive strength.

[0024] 6. The pre-pressing mold and hot press mold are combined to form the edge ribs 3 and the overall structure in stages, avoiding uneven material stretching or cracking caused by one-time molding.

[0025] 7. The edge pressure jig 21 and compression spring 22 dynamically adjust the edge pressure during hot pressing to ensure that the edge rib 3 is fully formed and without wrinkles. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the three-dimensional structure of a paper bowl;

[0027] Figure 2 This is a bottom view of the paper bowl;

[0028] Figure 3 This is a cross-sectional view of a paper bowl;

[0029] Figure 4 This is a structural diagram of the paper bowl composite paper;

[0030] Figure 5 This is a three-dimensional structural diagram of a paper bowl hot-pressing mold assembly.

[0031] Figure descriptions: 1. Side wall; 2. Bottom wall; 3. Side rib; 4. Annular bottom rib; 5. Base paper layer; 6. Functional layer; 7. Outward-facing edge; 8. Rounded transition edge; 9. Long side rib; 10. Short side rib; 11. Central boss; 13. Bottom mold; 14. Upper mold; 15. Shaping chamber; 16. Forming die head; 17. Heating chamber; 18. Heating coil; 19. Lifting fixture; 20. Optical axis; 21. Edge pressing fixture; 22. Compression spring. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings.

[0033] Example 1:

[0034] A paper bowl with a bottom rib structure includes a single sheet of molded composite paper. After molding, the composite paper forms a side wall 1 and a bottom wall 2. The side wall 1 is integrally molded with a side rib 3, and the bottom wall 2 is integrally molded with an annular bottom rib 4. The annular bottom rib 4 is concentrically arranged with the vertical central axis of the bottom wall 2.

[0035] This application uses composite paper hot pressing and shaping for preparation, which has the advantages of high production efficiency and low production cost compared with the bending and bonding of existing technologies. In addition to setting the side ribs 3, an additional bottom rib 4 is set, which can improve the structural strength of the bottom wall, meet the design requirements of larger bottom wall containers, and improve the three-dimensionality of the product, effectively improving the overall aesthetics. Moreover, compared with the flat bottom structure of existing technologies, the flatness requirement of the placement platform is lower. It should be noted that, due to the presence of the bottom ribs, when multiple applications of this application are stacked, there is a larger gap between adjacent ones, which is more conducive to the gripping of automated production lines.

[0036] The composite paper includes a base paper layer 5 and a functional layer 6, wherein the functional layer 6 is one or more of the following: a PP coating layer, a PET coating layer, a PE coating layer, a PLA coating layer, a PBS coating layer, or a plastic-free coating layer.

[0037] Multiple functional layer options (such as PP, PET, and plastic-free coatings) offer diverse performance characteristics (waterproof, temperature resistant, and environmentally friendly) to meet the needs of different scenarios. Plastic-free coatings align with environmental trends, avoiding microplastic pollution and improving product biodegradability. The multi-layered composite structure balances the support of the base paper with the protection of the functional layers, eliminating the need for additional coating processes.

[0038] The overall weight of the composite paper is 130g-300g, and the overall thickness of the composite paper is 0.2-0.5mm.

[0039] The balance between material cost and performance has been optimized to avoid excessive thinness leading to deformation or excessive thickness resulting in material waste. Clearly defined parameter ranges ensure that the paper bowls possess sufficient stiffness (heat insulation and anti-scalding) and flexibility (facilitating molding), reducing the defect rate.

[0040] The open end of the side wall 1 is provided with an outward-curved edge 7; the outward-curved edge 7 enhances the structural strength of the open end, prevents curling or tearing, and provides hand comfort and reduces the risk of burns; the flared edge design can be adapted to the sealing of the cup lid, improving the convenience of use.

[0041] A circular arc transition edge 8 is provided between the side wall 1 and the bottom wall 2; the circular arc transition edge 8 eliminates the right-angle connection between the side wall 1 and the bottom wall 2, reduces stress concentration, and prevents cracking when folded or under pressure; the streamlined structure enhances the aesthetic appearance and facilitates mold demolding, reducing production difficulty.

[0042] The edge reinforcement 3 includes a long edge reinforcement 9 and a short edge reinforcement 10, which are arranged alternately. The bottom end of the long edge reinforcement 9 extends to the annular bottom reinforcement 4, and the bottom end of the short edge reinforcement 10 extends to the arc transition edge 8.

[0043] The alternating layout of long and short side ribs creates a gradient support. The long side rib 9 transfers the bottom stress to the sidewall, while the short side rib 10 strengthens the transition zone, synergistically improving the overall compressive strength. The alternating design avoids material waste caused by excessive rib density, balancing lightweight and strength requirements.

[0044] The bottom wall 2 is integrally molded with a central boss 11, which is concentrically arranged with the annular bottom rib 4. The central boss 11 further disperses the bottom pressure, preventing the central area from collapsing when filled with high-temperature liquids and improving stability. The boss and the annular bottom rib 4 form a multi-level reinforcement structure, which is suitable for large-capacity paper bowls and significantly improves the load-bearing capacity.

[0045] Example 2:

[0046] A paper bowl hot pressing forming mold assembly includes a pre-pressing mold for pre-pressing to form edge ribs 3, and a hot forming mold for hot pressing and shaping. The hot forming mold includes a bottom mold 13 and an upper mold 14. The bottom mold 13 has a shaping chamber 15 that conforms to the outer surface of the paper bowl, and the upper mold 14 has a forming die head 16 that conforms to the inner surface of the paper bowl. The bottom mold 13 is provided with a heating chamber 17 around the shaping chamber 15, and a heating coil 18 is arranged in the heating chamber 17.

[0047] The pre-press mold and hot press mold are combined to form the edge ribs 3 and the overall structure in stages, avoiding uneven material stretching or cracking caused by one-time molding. The bottom mold 13 heating chamber is uniformly heated by coils, and the molding temperature is precisely controlled to ensure that the coating layer melts and adheres, reducing the risk of local overheating and carbonization.

[0048] The bottom mold 13 is connected to a lifting fixture 19 at its center.

[0049] The lifting fixture 9 enables automated demolding, avoiding damage to the paper bowl structure caused by manual peeling, improving production efficiency. Its height-adjustable design adapts to paper bowls of different heights, enhancing mold versatility.

[0050] The upper mold 14 is slidably connected to multiple optical axes 20. The bottom end of the optical axis 20 is fixed with a pressing fixture 21. The pressing fixture 21 is gap-fitted into the forming die head 16. Multiple compression springs 22 are provided between the pressing fixture 21 and the upper mold 14.

[0051] The edge-pressing fixture 21 and compression spring 22 dynamically adjust the edge pressure during hot pressing to ensure that the edge rib 3 is fully formed and wrinkle-free. The optical axis 20 guide structure ensures the edge-pressing accuracy, avoids misalignment of the edge rib due to uneven pressure, and improves product consistency.

[0052] The specific embodiments are merely explanations of this utility model and are not intended to limit it. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this utility model.

Claims

1. A thermoforming mold set for making a paper bowl having a bottom rib structure, characterized by: The assembly includes a pre-pressing mold for pre-pressing to form the edge ribs (3) and a thermoforming mold for hot pressing and shaping. The thermoforming mold includes a bottom mold (13) and an upper mold (14). The bottom mold (13) has a shaping chamber (15) that matches the outer surface of the paper bowl. The upper mold (14) has a forming die head (16) that matches the inner surface of the paper bowl. The bottom mold (13) has a heating chamber (17) around the shaping chamber (15). The heating chamber (17) is provided with a heating coil (18). The thermoforming mold assembly is used to process paper bowls with bottom rib structures. The paper bowl includes a single sheet of composite paper that has been molded and shaped. The composite paper has a side wall (1) and a bottom wall (2) after being molded and shaped. The side wall (1) is integrally molded to form the edge ribs (3). The bottom wall (2) is integrally molded to form an annular bottom rib (4). The annular bottom rib (4) and the vertical central axis of the bottom wall (2) are concentrically arranged.

2. A thermoforming mold set for making a paper bowl with a bottom rib structure according to claim 1, characterized in that: The composite paper includes a base paper layer (5) and a functional layer (6), wherein the functional layer (6) is one or more of the following: PP coating layer, PET coating layer, PE coating layer, PLA coating layer, PBS coating layer, or plastic-free coating layer.

3. A thermoforming mold set for making a paper cup with a bottom rib structure according to claim 2, characterized in that: The overall weight of the composite paper is 130g-300g, and the overall thickness of the composite paper is 0.2-0.5mm.

4. A thermoforming mold set for making a paper cup with a bottom rib structure according to claim 1, wherein: The sidewall (1) has an outwardly turned edge (7) at its open end.

5. A thermoforming mold set for making a paper cup with a bottom rib structure according to claim 1, wherein: An arc transition edge (8) is provided between the side wall (1) and the bottom wall (2).

6. A thermoforming mold assembly for preparing a paper bowl with a bottom rib structure according to claim 5, characterized in that: The side reinforcement (3) includes a long side reinforcement (9) and a short side reinforcement (10), which are arranged alternately. The bottom end of the long side reinforcement (9) extends to the annular bottom reinforcement (4), and the bottom end of the short side reinforcement (10) extends to the arc transition edge (8).

7. A thermoforming mold set for making paper cups with a bottom rib structure according to claim 1, characterized in that: The bottom wall (2) is integrally molded to form a central boss (11), and the central boss (11) and the annular bottom rib (4) are concentrically arranged.

8. A thermoforming mold set for making paper cups with a bottom rib structure according to claim 1, characterized in that: The bottom mold (13) is connected to a lifting fixture (19) at its center.

9. A thermoforming mold set for making paper cups with a bottom rib structure according to claim 1, characterized in that: The upper mold (14) is slidably connected to multiple optical axes (20), and a pressing fixture (21) is fixed at the bottom of the optical axis (20). The pressing fixture (21) is sleeved on the forming die head (16) with a gap. Multiple compression springs (22) are provided between the pressing fixture (21) and the upper mold (14).

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