Forming mechanism and paper cup machine

Abstract

The utility model discloses a forming mechanism and a paper cup machine, and the forming mechanism comprises a pressing male die which is provided with a first pressing side wall; the pressing concave die is provided with a pressing concave cavity for the pressing convex die to extend and enter, and the pressing concave cavity is provided with a second pressing side wall; wherein the first press-fit side wall / the second press-fit side wall comprises at least one first press-fit convex surface and at least one first press-fit concave surface, and when the press-fit convex die is matched with the press-fit concave die, a gap is formed between the first press-fit side wall and the second press-fit side wall to form a first press cavity and a second press cavity; the first pressing convex face is arranged on the inner surface of the first pressing cavity, the first pressing concave face is arranged on the inner surface of the second pressing cavity, the plane portion of the paper product is attached to the inner surface of the first pressing cavity, and the edge folding portion of the paper product is attached to the inner surface of the second pressing cavity. The whole paper is pressed and formed in a uniform tensioning mode in the downward stamping process, wrinkles generated after forming are reduced, the overall strength of the paper is improved, and meanwhile the stiffness of the paper is also improved.

Description

Technical Field

[0001] The present application relates to the technical field of paper product forming devices, and in particular to a paper cup forming mechanism. Background Art

[0002] With the improvement of environmental protection concept, disposable paper products are widely used. At present, disposable paper cups or paper plates are commonly used to hold various cakes or food snacks in the market. The manufacturing method of such paper cups or paper plates can refer to "A method for making disposable cake paper cups" disclosed in publication number CN115339150A. The paper cups or paper plates are manufactured by pressing and curling molds. In order to increase the strength of the formed paper cups, the folded edges are formed by the paper surface lamination process, and then the original one layer of paper surface is changed into multiple layers of paper surface to enhance the overall support strength of the paper cup.

[0003] At present, the types of paper cups with folded edges on the market include round and square ones. The folded edges of round folded paper cups are connected end to end in a circle, and the folded edges of square folded paper cups are either fully folded or partially folded. For example, the fully folded edge structure refers to the "A paper plate for air fryers that is not easy to deform and catch fire" disclosed in the announcement number CN218355776U, whose corrugated folds (folded edges) are connected end to end along the side wall. The partially folded edge refers to the appearance patent of a "baking paper pad (square)" disclosed in the announcement number CN307618569S, whose folded edges are set at the four corners, and the middle area of ​​the side wall is a flat part without folded edges.

[0004] During the forming process of paper products with partial folded edges, since the thickness of the folded edge is greater than the thickness of the flat surface without folded edge, the pressing force on the paper is uneven, which can easily cause the paper cup to become soft and wrinkled after forming, reducing the overall supporting strength. Utility Model Content

[0005] In order to improve the overall supporting strength of the paper cup after forming, the first purpose of the present application is to provide a forming mechanism.

[0006] A molding mechanism provided in this application adopts the following technical solution:

[0007] A forming mechanism, comprising:

[0008] A pressing male mold having a first pressing side wall; and

[0009] A pressing die having a pressing cavity into which the pressing convex die extends, wherein the pressing cavity has a second pressing side wall;

[0010] Among them, the first pressing side wall / the second pressing side wall includes at least one first pressing convex surface and at least one first pressing concave surface. When the pressing convex mold and the pressing concave mold are matched, there is a distance between the first pressing side wall and the second pressing side wall to form a first pressing cavity and a second pressing cavity. The first pressing convex surface is placed on the inner surface of the first pressing cavity, and the first pressing concave surface is placed on the inner surface of the second pressing cavity. The plane part of the paper product is in contact with the inner surface of the first pressing cavity, and the folded edge part of the paper product is in contact with the inner surface of the second pressing cavity.

[0011] By adopting the above technical scheme, when the pressing punch cooperates with the pressing die, the paper is placed between the two and is driven by the pressing punch to move part of the paper toward the pressing cavity of the pressing cavity. During the gradual pressing and molding process of the paper, the arrangement of the first pressing convex surface and the first pressing concave surface makes the thickness of the first pressing cavity smaller than the thickness of the second pressing cavity. Since the thickness of the folded edge of the paper is greater than the thickness of the flat portion, during the pressing process, the folded edge of the paper is placed in the first pressing cavity, and the flat portion of the paper is placed in the second pressing cavity, so that the force on the entire paper is uniform. Then, during the downward stamping process, the paper is pressed and molded as a whole in a uniformly tensioned form, which reduces the generation of wrinkles after molding, improves the overall strength of the paper, and at the same time improves the stiffness of the paper.

[0012] Preferably, the thickness of the second pressure chamber is an integer multiple of the thickness of the first pressure chamber.

[0013] By adopting the above technical solution, the thickness of the folded edge of the paper is an integer multiple of the flat portion, and the corresponding first pressure chamber for pressing the folded edge and the second pressure chamber for pressing the flat portion have thicknesses corresponding to the thicknesses of the folded edge and the flat portion, so that the paper can be better stretched in a tensioned state.

[0014] The thickness of the folded edge of the paper is an integer multiple of the flat surface. For example, if the folded edge is in a Z shape, one layer of folded edge is equal to the thickness of three layers of paper, and the thickness of the entire folded edge is an integer multiple of 3 of the flat surface. Of course, the folding forms of different folded edges are different, but the thickness of the folded edge after folding is an integer multiple of the flat surface.

[0015] Preferably, the pressing punch also includes a third pressing side wall connected to the first pressing side wall, and the pressing die also includes a fourth pressing side wall connected to the second pressing side wall, and the third pressing side wall / fourth pressing side wall include at least one second pressing convex surface and at least one second pressing concave surface; when the pressing punch and the pressing die are matched, there is a distance between the third pressing side wall and the fourth pressing side wall to form a third pressing cavity and a fourth pressing cavity, the second pressing convex surface is placed on the inner surface of the third pressing cavity, and the second pressing concave surface is placed on the inner surface of the fourth pressing cavity, the upper edge of the planar portion of the paper product is in contact with the inner surface of the third pressing cavity, and the upper edge of the folded edge portion of the paper product is in contact with the inner surface of the fourth pressing cavity.

[0016] By adopting the above technical scheme, the upper edge of the paper needs to be positioned after being punched and stretched to a certain depth, and the third pressing cavity and the fourth pressing cavity formed by the cooperation between the third pressing side wall and the fourth pressing side wall are used to position the upper edge of the paper. Also, since the thickness of the folded edge portion is greater than that of the plane portion, the second pressing convex surface and the second pressing concave surface are arranged so that the thickness of the fourth pressing cavity is greater than that of the third pressing cavity. The folded edge portion is placed in the fourth pressing cavity with a relatively large thickness, and the plane portion is placed in the third pressing cavity with a relatively small thickness. The force distribution on the upper edge of the paper is more uniform, and the upper edge portion is better pressed to be pressed and positioned.

[0017] Preferably, the thickness of the fourth pressure chamber is an integer multiple of the thickness of the third pressure chamber.

[0018] By adopting the above technical solution, the thickness of the folded edge of the paper is an integer multiple of the flat portion, and the thickness of the fourth pressure cavity is an integer multiple of the thickness of the third pressure cavity, which further makes the force during the paper pressing process more uniform and the quality after forming is better.

[0019] Preferably, it also includes:

[0020] A curling upper die, wherein the curling upper die is slidably connected to the pressing male die; and

[0021] A curling lower die, wherein the curling upper die is slidably connected to the pressing female die;

[0022] The upper curling die has a first curling groove at its upper end surface, and the lower curling die has a second curling groove at its upper end surface. When the upper curling die and the lower curling die contact each other, the first curling groove is connected to the second curling groove.

[0023] By adopting the above technical solution, after the paper is pressed and formed, the upper curling mold and the lower curling mold cooperate with each other to curl the outer edge of the paper. During the pressing process of the outer edge of the paper, the curling structure is formed in the first curling groove and the second curling groove, so that the pressing and curling are realized in one forming mechanism, thereby improving the forming efficiency.

[0024] Preferably, the curling lower die further comprises:

[0025] a fifth pressed side wall, the fifth pressed side wall comprising at least one third pressed convex surface and at least one third pressed concave surface;

[0026] Among them, when the pressing punch and the pressing die are matched, there is a distance between the fifth pressing side wall and the outer peripheral wall of the pressing punch to form a fifth pressing cavity and a sixth pressing cavity, the third pressing convex surface is placed on the inner surface of the fifth pressing cavity, and the third pressing concave surface is placed on the inner surface of the sixth pressing cavity, the upper edge of the flat part of the paper product is in contact with the inner surface of the fifth pressing cavity, and the upper edge of the folded edge of the paper product is in contact with the inner surface of the sixth pressing cavity.

[0027] By adopting the above technical scheme, since the thickness of the folded portion is greater than that of the flat portion, the paper is curled after the lamination is completed. During the curling process, the part of the paper that needs to be flipped extends from the fifth pressure chamber and the sixth pressure chamber to obtain a pressing and guiding effect. Due to the setting of the third lamination convex surface and the third lamination concave surface, the thickness of the corresponding fifth pressure chamber and the sixth pressure chamber is different. The folded portion is placed in the sixth pressure chamber with a relatively smaller thickness, and the flat portion is placed in the fifth pressure chamber with a relatively larger thickness, so that the upper edge of the paper is evenly stressed, the upper edge of the paper flips more smoothly during the curling process, and the overall molding effect is better.

[0028] Preferably, the thickness of the sixth pressure chamber is an integer multiple of the thickness of the fifth pressure chamber.

[0029] By adopting the above technical solution, the thickness of the folded edge of the paper is an integer multiple of the flat portion, and the thickness of the sixth pressure cavity is an integer multiple of the fifth pressure cavity, which further makes the force on the upper edge of the paper more uniform and the quality of the curled edge after forming is better.

[0030] In order to improve the overall supporting strength of the paper cup after forming, the second purpose of the present application is to provide a paper cup machine.

[0031] A molding mechanism provided in this application adopts the following technical solution:

[0032] A paper cup machine, comprising the forming mechanism

[0033] By adopting the above technical solution, the thickness difference between the folded edge part and the flat edge part is taken into account during the paper forming process, and the thickness of the forming pressure cavity is adjusted accordingly to make the pressing force on the paper more uniform. The pressing and curling operation is completed under the tension state as a whole, so that the paper after forming has higher stiffness and reduces the occurrence of wrinkles, thereby improving the overall support strength after forming.

[0034] In summary, the present application includes at least one of the following beneficial technical effects:

[0035] 1. By setting the thickness of the first pressure chamber and the second pressure chamber, the outer peripheral wall of the main body is subjected to more uniform pressure during the paper pressing process. The third pressure chamber and the fourth pressure chamber are combined to press the upper edge of the paper after pressing. The thickness setting of the third pressure chamber and the fourth pressure chamber makes the upper edge of the paper more uniform. At the same time, the thickness setting of the fifth pressure chamber and the sixth pressure chamber makes it possible to better press the upper edge of the paper under the premise of uniform force when the paper is curling, so that the curling operation is smoother and the overall strength after forming is better.

[0036] 2. By setting the thickness of each pressure cavity to match the thickness ratio of the folding portion and the flat portion, the force during the paper forming process is further made more uniform, and the overall strength of the formed product is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is an exploded schematic diagram of the forming mechanism in the first embodiment;

[0038] Figure 2 It is a schematic diagram mainly showing the first pressing convex surface and the first pressing concave surface in the pressing convex mold in the first embodiment;

[0039] Figure 3 It is a schematic diagram mainly showing the first pressure cavity and the second pressure cavity after the pressing punch and the pressing groove are matched in the first embodiment;

[0040] Figure 4 is a cross-sectional view of the forming mechanism in the first embodiment;

[0041] Figure 5 This is a schematic diagram showing the direct connection between the first pressure chamber, the third pressure chamber and the fifth pressure chamber in the first embodiment;

[0042] Figure 6 It is a schematic diagram of the connection between the pressing die and the curling lower die in the first embodiment;

[0043] Figure 7 A schematic diagram of the relationship between the forming mechanism and the paper in the initial state in the first embodiment;

[0044] Figure 8 It is a schematic diagram of the molding mechanism in the first embodiment when completing the pressing process.

[0045] Explanation of the reference numerals in the accompanying drawings: 1. Pressing punch; 11. Mold core; 111. First pressing convex surface; 112. First pressing concave surface; 113. Second pressing convex surface; 114. Second pressing convex surface; 12. Main body; 13. First pressing cavity; 14. Second pressing cavity; 15. Third pressing cavity; 16. Fifth pressing cavity; 2. Pressing concave mold; 21. Pressing concave cavity; 22. Second pressing side wall; 23. Fourth pressing side wall; 24. Guide surface; 3. Curling upper mold; 31. First curling groove; 4. Curling lower mold; 41. Guide groove; 42. Second curling groove; 43. Third pressing convex surface; 44. Fourth pressing convex surface; 5. Paper. DETAILED DESCRIPTION

[0046] The present application is further described in detail below in conjunction with the accompanying drawings.

[0047] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of this application. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. Embodiment 1

[0049] Figure 1 The structure of a forming mechanism of the present embodiment is shown, including a pressing punch 1, a pressing die 2, a curling upper die 3 and a curling lower die 4, wherein the curling upper die 3 is slidably connected to the upper portion of the pressing punch 1, and the curling lower die 4 is slidably connected to the pressing die 2. During actual application and installation, the pressing die 2 and the curling lower die 4 are installed on a workbench, the pressing punch 1 and the curling upper die 3 are placed above the pressing die 2 and connected to a power source, and the pressing punch 1 and the curling upper die 3 are driven by an external power source to move away from or close to the pressing die 2.

[0050] The upper curling die 3 and the lower curling die 4 are both provided with guide grooves 41, and the pressing convex die 1 and the pressing concave die 2 are both placed in the guide grooves 41 and can slide relative to each other. The pressing convex die 1 includes an integrated main body 12 and a core 11 extending outward from one end of the main body 12. The core 11 has a certain taper and is distributed similar to a step between the main body 12. The main body 12 is placed in the guide groove 41 to achieve sliding. The pressing concave die 2 is provided with a pressing cavity 21 with an opening on one side, and the core 11 can extend into the pressing cavity 21 to achieve a matching connection between the pressing convex die 1 and the pressing concave die 2.

[0051] Combination Figure 2 and Figure 3The mold core 11 has a first pressing side wall. In this embodiment, the first pressing side wall includes a plurality of first pressing convex surfaces 111 and a first pressing concave surface 112 connected in sequence. The pressing concave cavity 21 has a second pressing side wall 22. In this embodiment, the second pressing side wall 22 is a smooth surface. When the pressing convex mold 1 and the pressing concave mold 2 are matched, a gap is left between the first pressing convex surface 111 and the second pressing side wall 22 to form a first pressing cavity 13, and a gap is left between the first pressing concave surface 112 and the second pressing side wall 22 to form a second pressing cavity 14; wherein, the thickness of the second pressing cavity 14 is greater than the thickness of the first pressing cavity 13. Preferably, in a paper product with a folded edge, the thickness of the folded edge is greater than the thickness of the flat portion without the folded edge. During the pressing and forming process, the folded edge is attached to the inner surface of the second pressing cavity 14, and the flat portion is attached to the inner surface of the first pressing cavity 13. At the same time, the thickness of the second pressing cavity 14 is an integer multiple of the thickness of the first pressing cavity 13, and the thickness ratio of the second pressing cavity 14 to the first pressing cavity 13 is equal to the thickness ratio between the folded edge and the flat portion, so that the main body 12 of the entire paper product can be completely and tightly attached to the first pressing side wall and the second pressing side wall 22.

[0052] In actual application, the thickness of one folded edge of the paper product is three times the thickness of the portion of the paper 5 without the folded edge. When the folded edge has n layers, the thickness of the entire folded edge is 3n times the thickness of the portion of the paper 5 without the folded edge, that is, the thickness ratio of the second pressure chamber 14 to the first pressure chamber 13 is equal to the thickness ratio between the folded edge and the flat surface.

[0053] Combination Figure 4 and Figure 5 The pressing punch 1 also includes a third pressing side wall connected to the first pressing side wall, and the pressing die 2 also includes a fourth pressing side wall 23 connected to the second pressing side wall 22. The third pressing side wall and the fourth pressing side wall 23 are both inclined and have the same inclination angle.

[0054] The third pressed side wall includes a plurality of second pressed convex surfaces 114113 and second pressed concave surfaces connected in sequence, the second pressed convex surface 114113 is connected to the first pressed convex surface 111, the second pressed concave surface is connected to the first pressed concave surface 112, and the second pressed convex surface 114113 and the second pressed concave surface are arranged at the end of the mold core 11 and connected to the main body 12.

[0055] The fourth pressing side wall 23 is smooth and is arranged at the opening of the pressing cavity 21. When the pressing convex mold 1 and the pressing cavity 2 are matched, a gap is left between the second pressing convex surface 114113 and the fourth pressing side wall 23 to form the third pressing cavity 15, and a gap is left between the second pressing concave surface and the fourth pressing side wall 23 to form the fourth pressing cavity. At the same time, the thickness of the fourth pressing cavity is an integer multiple of the thickness of the third pressing cavity 15, and the thickness ratio of the fourth pressing cavity to the third pressing cavity 15 is equal to the thickness ratio between the folding part and the plane part. In addition, the third pressing cavity 15 is connected to the first pressing cavity 13, and the fourth pressing cavity is connected to the second pressing cavity 14, so that the upper edge of the entire paper product can be completely and tightly fitted with the third pressing side wall and the fourth pressing side wall 23.

[0056] The curling lower die 4 further includes a fifth pressing side wall at the guide groove 41, and the fifth pressing side wall includes a plurality of third pressing convex surfaces 43 and third pressing concave surfaces connected in sequence, and the third pressing convex surfaces 43 and the third pressing concave surfaces extend downward from the notch side of the guide groove 41 to a certain length. The pressing concave die 2 is provided with a guide surface 24 on the outer peripheral wall for the third pressing convex surface 43 to extend into, so that the pressing concave die 2 and the curling lower die 4 have better sliding guiding properties.

[0057] When the pressing punch 1 and the pressing die 2 are matched, a distance is left between the third pressing convex surface 43 and the outer peripheral wall of the main body 12 to form the fifth pressing cavity 16, and a distance is left between the third pressing concave surface and the outer peripheral wall of the main body 12 to form the sixth pressing cavity. At the same time, the thickness of the sixth pressing cavity is an integer multiple of the thickness of the fifth pressing cavity 16, and the thickness ratio of the sixth pressing cavity to the fifth pressing cavity 16 is equal to the thickness ratio between the folded edge portion and the flat portion, so that the upper edge of the entire paper product is more closely fitted with the fifth pressing side wall and the outer peripheral wall of the main body 12.

[0058] In addition, the fifth pressure chamber 16 is communicated with the third pressure chamber 15, and the sixth pressure chamber is communicated with the fourth pressure chamber, so that the paper 5 is completely tensioned and pressed during the lamination process.

[0059] At the same time, the forming mechanism can also realize the curling process of the paper 5. Specifically, the curling upper mold 3 is provided with a first curling groove 31 at the upper end surface, and the curling lower mold 4 is provided with a second curling groove 42 at the upper end surface. The first curling groove 31 and the second curling groove 42 are both close to one side of the guide groove 41. When the curling upper mold 3 and the curling lower mold 4 conflict with each other, the first curling groove 31 and the second curling groove 42 are connected to each other.

[0060] When the forming mechanism presses and curls the paper 5, the paper 5 is placed on the end surface of the curling lower die 4, and the curling punch and the curling lower die 4 move toward one side of the curling concave die with the external power source. During the downward process, the pressing punch 1 presses and stretches the paper 5. At the same time, the paper 5 is formed into a folded portion under the action of the folding die. The folding die is respectively connected to the curling upper die 3 and the curling lower die 4, and moves synchronously with the downward movement of the curling upper die 3.

[0061] After the pressing is completed, the pressing convex die 1 contacts the pressing cavity 21 of the pressing concave die 2, and the upper curling die 3 continues to move downward and pushes the lower curling die 4 downward, and as the vertical heights of the fifth pressing cavity 16 and the sixth pressing cavity gradually decrease, the curling process of the paper 5 is realized. In the process of pressing and curling the paper 5 by the forming mechanism, the paper 5 can be completely fitted into the pressing cavity, and the force on the paper 5 is evenly distributed, thereby reducing the wrinkling caused by uneven force, and greatly improving the overall strength of the formed product.

[0062] In another embodiment, the first pressing convex surface 111 and the first pressing concave surface 112 can also be arranged on the first pressing side wall of the pressing die 2, the second pressing convex surface 114113 and the second pressing concave surface are arranged on the fourth pressing side wall 23, and the second pressing side wall 22 and the third pressing side wall are smooth.

[0063] In another embodiment, the first pressing convex surface 111 and the first pressing concave surface 112 can also be arranged on the second pressing side wall 22 of the pressing die 2, the second pressing convex surface 114113 and the second pressing concave surface are arranged on the third pressing side wall, and the first pressing side wall and the fourth pressing side wall 23 are smooth surfaces.

[0064] In another embodiment, the first pressing convex surface 111 and the first pressing concave surface 112 can also be arranged on the second pressing side wall 22 of the pressing die 2, and the second pressing convex surface 114113 and the second pressing concave surface can also be arranged on the fourth pressing side wall 23. In this case, the first pressing side wall and the third pressing side wall are smooth. Embodiment 2

[0065] A paper cup machine comprises the forming mechanism in the first embodiment.

[0066] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A forming mechanism, characterized in that: include: A pressing male die (1) having a first pressing side wall; as well as A pressing die (2) having a pressing cavity (21) for the pressing convex die (1) to extend into, the pressing cavity (21) having a second pressing side wall (22); The first pressing side wall / second pressing side wall (22) comprises at least one first pressing convex surface (111) and at least one first pressing concave surface (112); when the pressing convex mold (1) and the pressing concave mold (2) are matched, a distance is provided between the first pressing side wall and the second pressing side wall (22) to form a first pressing cavity (13) and a second pressing cavity (14); the first pressing convex surface (111) is arranged on the inner surface of the first pressing cavity (13); the first pressing concave surface (112) is arranged on the inner surface of the second pressing cavity (14); the plane portion of the paper product is in contact with the inner surface of the first pressing cavity (13); and the folded edge portion of the paper product is in contact with the inner surface of the second pressing cavity (14).

2. The forming mechanism according to claim 1, characterized in that: The thickness of the second pressure chamber (14) is an integer multiple of the thickness of the first pressure chamber (13).

3. The forming mechanism according to claim 1, characterized in that: The pressing convex mold (1) further comprises a third pressing side wall connected to the first pressing side wall, and the pressing concave mold (2) further comprises a fourth pressing side wall (23) connected to the second pressing side wall (22), and the third pressing side wall / fourth pressing side wall (23) comprises at least one second pressing convex surface (114) (113) and at least one second pressing concave surface; when the pressing convex mold (1) and the pressing concave mold (2) are matched, a distance is provided between the third pressing side wall and the fourth pressing side wall (23) to form a third pressing cavity (15) and a fourth pressing cavity, the second pressing convex surface (114) (113) is arranged on the inner surface of the third pressing cavity (15), the second pressing concave surface is arranged on the inner surface of the fourth pressing cavity, the upper edge of the plane portion of the paper product is in contact with the inner surface of the third pressing cavity (15), and the upper edge of the folded edge portion of the paper product is in contact with the inner surface of the fourth pressing cavity.

4. The forming mechanism according to claim 3, characterized in that: The thickness of the fourth pressure chamber is an integer multiple of the thickness of the third pressure chamber (15).

5. The forming mechanism according to claim 1, characterized in that: Also includes: A curling upper die (3), wherein the curling upper die (3) is slidably connected to the pressing convex die (1); as well as A curling lower die (4), wherein the curling upper die (3) is slidably connected to the pressing die (2); The upper curling die (3) is provided with a first curling groove (31) at the upper end surface, and the lower curling die (4) is provided with a second curling groove (42) at the upper end surface; when the upper curling die (3) and the lower curling die (4) are in contact with each other, the first curling groove (31) and the second curling groove (42) are connected.

6. The forming mechanism according to claim 5, characterized in that: The curling lower die (4) also includes: A fifth pressed side wall, the fifth pressed side wall comprising at least one third pressed convex surface (43) and at least one third pressed concave surface; When the pressing convex mold (1) and the pressing concave mold (2) are matched, a distance is provided between the fifth pressing side wall and the outer peripheral wall of the pressing convex mold (1) to form a fifth pressing cavity (16) and a sixth pressing cavity, the third pressing convex surface (43) is arranged on the inner surface of the fifth pressing cavity (16), the third pressing concave surface is arranged on the inner surface of the sixth pressing cavity, the upper edge of the plane portion of the paper product is in contact with the inner surface of the fifth pressing cavity (16), and the upper edge of the folded edge portion of the paper product is in contact with the inner surface of the sixth pressing cavity.

7. The forming mechanism according to claim 6, characterized in that: The thickness of the sixth pressure chamber is an integer multiple of the thickness of the fifth pressure chamber (16).

8. A paper cup machine, characterized in that: It comprises a forming mechanism as described in any one of claims 1 to 7.

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