A pulp egg box forming mould

Abstract

The utility model provides a kind of paper pulp egg box forming die, including upper die plate and lower die plate, the upper die plate is equipped with egg box die core, the lower die plate is equipped with the egg box die cavity matched with the egg box die core, the egg box die core includes bottom box core and upper cover core, the long side of the upper cover core one side is equipped with side edge insert piece, recess is formed between the long side of the side edge insert piece and the upper cover core;The egg box die cavity includes the bottom box cavity matched with the bottom box core and the upper cover cavity matched with the upper cover core, the long side of the upper cover cavity is equipped with the protruding part protruding to the upper cover core with the position corresponding the recess position. Reverse edge pressing design is realized by protruding part and recess cooperation, and the long side of the egg box upper cover edge problem is radically solved from forming mechanism, and smooth edge is formed at one time, so that subsequent edge finishing process is saved while improving product quality, and cost reduction and efficiency increase are realized.

Description

Technical Field

[0001] This utility model relates to the technical field of pulp molding production equipment, specifically to a pulp egg carton molding mold. Background Technology

[0002] Pulp molding is an environmentally friendly packaging material. It involves adsorbing pulp onto a molding die to form a wet preform, which is then shaped under high temperature and pressure using a hot press to obtain the desired product. In the production of high-end egg cartons, a wet pressing process is commonly used for one-time, integrated molding, meaning the top cover, bottom box, and connecting hinges are completed simultaneously within a single molding cycle. This process produces egg cartons with a sturdy structure and a smooth appearance, effectively enhancing the product's image.

[0003] In existing technologies, the thermoforming molds used for this type of one-piece molded egg carton typically consist of an upper mold and a lower mold that cooperate with each other. During mold closing, the wet pulp blank is pressed and dried within the cavity formed by the upper and lower molds. However, in actual production, when the mold is opened after thermoforming, a tiny gap or mating surface exists between the upper and lower mold cavities corresponding to the long side of the egg carton lid. Because the pulp fibers are not completely cured and cut after thermoforming, the fibers remaining in this gap area are stretched and torn at the moment of mold separation, rather than being neatly cut. This results in a large amount of burrs, flash, or fibrous material on the long edge of the molded egg carton lid.

[0004] This directly affects the appearance and aesthetics of the product, making it difficult to meet the demands of the high-end market; secondly, loose fiber burrs may fall off during transportation and use, contaminating the eggs; and thirdly, removing these burrs often requires additional finishing processes, such as manual trimming or mechanical polishing, which not only increases production costs but also reduces production efficiency. Utility Model Content

[0005] The purpose of this utility model is to provide a pulp egg carton molding mold, which aims to solve the problem that the long edge of the egg carton lid is prone to produce a lot of burrs when the mold is opened in the prior art.

[0006] To achieve the above objectives, this utility model provides a pulp egg carton forming mold, including an upper template and a lower template. The upper template contains an egg carton mold core, and the lower template has an egg carton mold cavity that mates with the egg carton mold core. The egg carton mold core includes a bottom core and an upper cover core. A side insert is provided on one long side of the upper cover core, and a recess is formed between the side insert and the long side of the upper cover core. The egg carton mold cavity includes a bottom cavity that mates with the bottom core and an upper cover cavity that mates with the upper cover core. A protrusion protruding towards the upper cover core is provided on the long side of the upper cover cavity corresponding to the position of the recess. When the upper template and the lower template are closed, the protrusion is embedded in the recess, and the rough edges of the pulp located in the recess are pressed back into the gap formed by the protrusion and the recess to form a smooth flange.

[0007] Furthermore, the side insert is detachably connected to one long side of the upper cover core.

[0008] Furthermore, a mold closing guide mechanism is provided between the upper and lower templates.

[0009] Furthermore, the mold closing guide mechanism includes a guide post disposed on the upper mold plate and a guide sleeve disposed on the lower mold plate and adapted to the guide post.

[0010] Furthermore, the guide post has a T-shaped cross-section, and the guide sleeve has a concave structure that mates with the guide post.

[0011] Furthermore, the cross-section of the protrusion is either trapezoidal or arc-shaped.

[0012] Furthermore, the egg carton mold cavity is provided with a groove for cooperating with the side insert during mold closing.

[0013] The pulp egg carton molding die provided by this utility model, compared with the prior art, achieves a reverse pressing edge design through the cooperation of the protrusion and the concave part, which fundamentally solves the problem of rough edges on the long side of the egg carton lid from the molding mechanism, and forms a smooth edge in one go. This not only improves product quality, but also saves the subsequent trimming process, thereby reducing costs and increasing efficiency. Attached Figure Description

[0014] Figure 1 This is a schematic cross-sectional view of the molded pulp egg carton forming mold of the present invention in the mold-closed state; Figure 2 for Figure 1 Enlarged view of section A in the middle; Figure 3 This is an exploded view of a pulp egg carton molding die according to the present invention; Figure 4This is an exploded view from another perspective of the pulp egg carton molding mold of this utility model.

[0015] Explanation of reference numerals in the attached figures 10-Upper mold; 11-Egg carton mold core; 12-Bottom box core; 13-Top cover core; 14-Side insert; 15-Recessed part; 20 - Lower mold plate; 21 - Egg carton mold cavity; 22 - Bottom box cavity; 23 - Upper cover cavity; 24 - Protrusion; 25 - Groove; 30 - Guide post; 31 - Guide sleeve. Detailed Implementation

[0016] The present invention will be described in detail below with reference to specific embodiments.

[0017] In this utility model, when directional terms appear, they are used to facilitate the description of this utility model and simplify the description, rather than indicating or implying that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of this utility model.

[0018] In this utility model, unless otherwise explicitly specified and limited, when terms such as "set in," "connected," or "linked" appear, these terms should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can also refer to a mechanical connection; they can refer to a direct connection or a connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0019] Example 1 like Figures 1 to 4 As shown in the figure, this utility model provides a pulp egg carton molding die for one-time hot pressing molding of an integrated pulp egg carton. The die mainly includes an upper mold plate 10 and a lower mold plate 20, which are precisely aligned by a mold closing guide mechanism.

[0020] An egg carton mold core 11 is provided within the upper template 10. The egg carton mold core 11 includes a bottom core 12 for forming the bottom of the egg carton and an upper cover core 13 for forming the top cover of the egg carton. A side insert 14 is detachably connected to the long side of the upper cover core 13 by bolts. This detachable design facilitates the replacement, maintenance, and adjustment of this component for different product models. A continuous recess 15 is formed in the height direction between the side insert 14 and the long side wall of the upper cover core 13.

[0021] The lower template 20 is provided with an egg carton cavity 21 that precisely matches the egg carton mold core 11. The egg carton cavity 21 includes a bottom box cavity 22 that matches the bottom box core 12 and an upper cover cavity 23 that matches the upper cover core 13. On the long edge of the upper cover cavity 23, a protrusion 24 is provided at the position opposite to the recess 15, protruding into the mold.

[0022] In this embodiment, the cross-section of the protrusion 24 is preferably trapezoidal, which is beneficial for mold closing and demolding. At the same time, a groove 25 is provided on the lower mold plate 20 at the position corresponding to the side insert 14, which is used to accommodate the side insert 14 during mold closing and avoid interference.

[0023] The mold closing guide mechanism includes a guide post 30 fixedly installed on the upper mold plate 10 and a guide sleeve 31 fixedly installed on the lower mold plate 20. The guide post 30 has a T-shaped cross-section, and correspondingly, the guide sleeve 31 has a concave structure that precisely matches it. This non-circular guide fit can effectively prevent relative rotation between the upper and lower mold plates 20 during the mold closing process, ensuring extremely high mold closing alignment accuracy.

[0024] Working principle and process: Before mold closing, the wet pulp blank is placed inside the egg carton cavity 21 of the lower mold plate 20. During mold closing, the upper mold plate 10 moves downward under power drive, and the T-shaped guide post 30 first inserts into the concave guide sleeve 31 to achieve initial guidance and coarse positioning. As the mold closing action continues, the guiding mechanism ensures that the upper mold plate 10 and the lower mold plate 20 achieve precise alignment.

[0025] At this point, the upper cover core 13 and the upper cover gradually close. Crucially, the protrusion 24 precisely embeds into the recess 15. The raw edges of the wet pulp blank located in this area are intensely squeezed, sheared, and reshaped within the gradually narrowing gap formed by the protrusion 24 and the recess 15. This "reverse pressing" action firmly presses loose fibers that might otherwise form burrs or flakes onto the product edge, ultimately creating a smooth, dense, and aesthetically pleasing folded edge.

[0026] After molding, a one-piece pulp egg carton with a smooth and flat long edge on the top cover can be obtained, which fundamentally eliminates burrs and eliminates the need for subsequent trimming processes.

[0027] Example 2 In another embodiment, the cross-section of the protrusion 24 can also be arc-shaped. This streamlined design also achieves effective reverse edge pressing and may yield better molding results in certain pulp formulations or product designs. All other structures in this embodiment are the same as in Embodiment 1.

[0028] The pulp egg carton molding die provided by this utility model, compared with the prior art, achieves a reverse pressing edge design through the cooperation of the protrusion 24 and the recess 15, which fundamentally solves the problem of rough edges on the long side of the egg carton lid from the molding mechanism, and forms a smooth edge in one go. This not only improves product quality, but also eliminates the need for subsequent trimming processes, thereby reducing costs and increasing efficiency.

[0029] Where there is no conflict, the above embodiments and features can be combined with each other.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit the scope of protection of this utility model. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the essence and scope of the technical solutions of this utility model.

Claims

1. A pulp egg carton forming mold, comprising an upper template and a lower template, wherein an egg carton mold core is provided within the upper template, and an egg carton mold cavity is provided on the lower template to cooperate with the egg carton mold core, characterized in that: The egg carton mold core includes a bottom box core and an upper cover core. A side insert is provided on one side of the long side of the upper cover core, and a recess is formed between the side insert and the long side of the upper cover core. The egg carton cavity includes a bottom box cavity that mates with the bottom box core and an upper cover cavity that mates with the upper cover core. The long side of the upper cover cavity is provided with a protrusion that protrudes toward the upper cover core at the position corresponding to the recessed part. When the upper and lower molds are closed, the protrusion is embedded in the recess, and the rough edges of the pulp located in the recess are pressed back into the gap formed by the protrusion and the recess to form a smooth flange.

2. A paper pulp egg carton forming mold according to claim 1, wherein, The side insert is detachably connected to one side of the long side of the upper cover core.

3. A paper pulp egg carton forming mold according to claim 1 or 2, characterized in that A mold closing guide mechanism is provided between the upper and lower templates.

4. The pulp egg carton forming mold according to claim 3, characterized in that, The mold closing guide mechanism includes a guide post disposed on the upper mold plate and a guide sleeve disposed on the lower mold plate and adapted to the guide post.

5. A paper pulp egg carton forming mold according to claim 4, wherein, The guide post has a T-shaped cross-section, and the guide sleeve has a concave structure that mates with the guide post.

6. A paper pulp egg carton forming mold according to claim 1 or 2, wherein The cross-section of the protrusion is either trapezoidal or arc-shaped.

7. A paper pulp egg carton forming mold according to claim 1 wherein, The egg carton mold cavity is provided with grooves for cooperating with the side inserts when the mold is closed.

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