JPH053976B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method and apparatus for forming a paper plate having a hem formed around its outer periphery.

[Prior Art] FIG. 15 is an end view of a conventional paper plate.
Such a plate 1 is usually formed by pressing paperboard cut into predetermined dimensions and forming folds and wrinkles in curved portions and the like. In the conventional paper plate 1, the outer peripheral portion 1a remains in a so-called separated state.

FIG. 14 is a sectional view showing the conventional paper plate forming apparatus shown in FIG. 15. In Figure 14,
A mold member 2 is attached to the base portion 10. A cylindrical part 4 is attached to the base part 9 opposite to the mold member 2, and an inner mold member 3 is provided inside the cylindrical part 4, and an outer mold member 5 is provided on the outside. The inner mold member 3 is attached while being biased by a spring 6. The outer mold member 5 is biased by springs 7 and 8 and attached to the base portion 9. A frame 11 is provided around the outer mold member 5.

In the conventional apparatus, the paperboard 12 is positioned between the mold member 2, the inner mold member 3, and the outer mold member 5, and the paperboard 12 is sandwiched between these mold members and press-worked. In such conventional equipment,
Usually, the mold member 2, the inner mold member 3, and the outer mold member 5 are provided so as to be positioned in the horizontal direction, thereby forming a horizontal molding apparatus.

[Problem to be solved by the invention] However, in such a conventional paper plate 1,
Since the outer peripheral part 1a is in a separated state, when a load is applied, the fold wrinkles formed near the outer peripheral part will stretch, making it impossible to ensure sufficient bending strength of the paper plate as a whole. Furthermore, since the cut surface of the paper is exposed on the outer periphery, liquids such as seasonings tend to seep into the paper plate, which not only weakens the paper plate itself but also makes it unsanitary. Furthermore, since the outer periphery of the paper plate is separated, it gives a so-called flimsy impression and is inferior in aesthetics and texture. Moreover, when using the paper, the cut surface of the paper tends to come into direct contact with the mouth, making it difficult to touch the lips.
Therefore, in order to overcome these drawbacks of conventional paper plates, there has been a desire for a paper plate in which the outer periphery of the paper plate is curled to form an edge.

It is known that plates made of aluminum foil have a border around the outer periphery, but it is difficult to apply this method of forming aluminum foil plates to paper plates with a border. It was hot. This is because the paper used for paper plates is much thicker than aluminum foil, and cannot be easily plasticized like aluminum foil.
In other words, aluminum foil has a thickness of 0.15mm or less, while paper used for paper plates has a thickness of 0.22mm to 0.45mm.
(200g/m ² - 400g/m ² ) thick white paperboard, etc., and if you try to form an edge using the conventional method, it may be difficult to form fold wrinkles evenly over the whole, or the edges may be This resulted in the problem that the rolled portions would stick up.

SUMMARY OF THE INVENTION An object of the present invention is to provide a molding method and a molding apparatus that are capable of forming an edge of a paper plate at the same time as forming the paper plate.

[Means for Solving the Problems] The forming method according to claim 1 includes pressing paperboard on which a plurality of substantially radially extending filaments are formed, folding along the filaments to form wrinkles, and shaping the paperboard into a predetermined shape. This is a method of curling the outer periphery of the paperboard to form a hem. This method involves the process of compacting the outer periphery of the paperboard, and forming an annular shape along the outer periphery of the paperboard, with the inner wall surface being curled. The method includes the step of inserting the outer circumferential portion of the compacted paperboard into a curling groove that is curved in the curling direction and having a guide groove along the curling direction, and curling the paperboard to form an edge wrap.

The forming apparatus according to claim 2 presses a paperboard on which a plurality of filaments extending substantially radially are formed, folds and wrinkles along the filaments to form the paperboard into a predetermined shape, and also presses the paperboard on which a plurality of filaments extending substantially radially are formed, forms the paperboard into a predetermined shape by folding and wrinkles along the filaments, and forms the paperboard into a predetermined shape. This is a device that curls paperboard to form a hem, and includes a pair of mold members that form a predetermined shape by sandwiching paperboard and pressing it, and a device that is installed around each pair of mold members, and presses A pair of outer frame members are provided so as to abut each other during processing, and on the inside of the abutting surfaces of the pair of outer frame members, annular grooves are formed along the abutting surfaces so as to face each other. is formed, and the inner wall surface of the groove is curved in the curling direction and has a guide groove along the curling direction, and when the outer frame members collide, the respective grooves coincide with each other and become continuous to prevent curling. The outer periphery of the paperboard is sandwiched between a pair of outer frame members and compacted, and the paperboard is pressed into a predetermined shape using a pair of die members. After that, the outer periphery of the rammed paperboard is inserted into the curling groove formed by the pair of outer frame members abutting against each other, and the outer periphery of the rammed paperboard is curled to form an edge wrap.

[Function] The most difficult problem in forming a hem on the outer periphery of a paper plate is that the thickness of the hem, which is the edge, cannot be made uniform throughout. That is, a paper plate is shaped into a predetermined shape by forming fold wrinkles in the deformed portion, but the amount of fold wrinkles increases as the area approaches the outer periphery, and the paper plate is more susceptible to the effects thereof. Therefore, unless the fold wrinkles are uniformly formed on the outer periphery, the thickness will vary greatly and it will be difficult to form a hemline.

In the forming method of the first aspect, the outer peripheral portion of the paperboard is first compacted, and the outer peripheral portion is compressed to increase the density of the paper. As a result, when curling,
This prevents the edges of the outer periphery from becoming loose. The surface is also smoothed to reduce frictional resistance and allow for smooth curling.

Next, the outer periphery of the compacted paperboard is inserted into the curling groove to form a hem wrap. A guide groove is formed in this curl groove along the curling direction, and when the outer periphery of the paperboard with wrinkles and an uneven surface is inserted, curling is performed along this guide groove. Therefore, edge wrapping is performed with the fold wrinkles appropriately dispersed. For this reason, it is possible to prevent occurrence of large, irregularly shaped wrinkles, or the occurrence of wrinkled portions overlapping each other, resulting in an increase in thickness and clogging in the curl groove.

The forming apparatus according to claim 2 is provided with a pair of outer frame members for compacting the outer periphery of the paperboard so that edge wrapping can be performed in the same manner as in the method according to claim 1. A groove portion is formed in each outer frame member so that a curl groove having a guide groove is formed when the pair of outer frame members abut each other.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of the present invention. In the apparatus shown in FIG. 1, a first mold member 21 and a second mold member 2 are used as a pair of mold members.
2 is provided. A first outer frame member 23 is provided around the first mold member 21.
The outer frame member 23 is attached to the pedestal part 27. The lower end of the first outer frame member 23 projects inward to form a locking portion 23a, and the upper end of the first mold member 21 projects outward to form a locking portion 21a. The first mold member 21 is biased downward by springs 29 and 30 provided between it and the pedestal 27, and due to the locking between the locking portions 21a and 23a, the first mold member 21 21 is locked.

The second mold member 22 is attached to the pedestal section 28 via a support plate section 33. Second mold member 22
An annular second outer frame member 24 is provided around the. The second outer frame member 24 is biased upward by springs 31 and 32, one end of which is attached to the base portion 28. Second outer frame member 24
The lower part of the second mold member 22 projects inward to form a locking part 24a, and the upper part of the second mold member 22 projects outward to form a locking part 22a. This locking part 2
2a and the locking portion 24a, the second outer frame member 2
The upward movement of 4 is regulated and positioned.

The second outer frame member 24 has a spring receiving portion 24b.
and 24c are formed, and one end of springs 35 and 36 are attached to each. A positioning ring 34 is mounted on the other end of these springs 35 and 36. This positioning ring 34 is located around the upper part of the second outer frame member 24, and its upper end is attached to springs 35 and 36 so that it is slightly higher than the upper end of the second outer frame member 24. Therefore, the position is set. This positioning ring 34 allows the second
The paperboard 60 placed on the upper end of the outer frame member 24 is positioned so as not to shift from a predetermined position.

A heater 38 is provided at an appropriate location between the first outer frame member 23 and the pedestal portion 27. Also the second
A heater 3 is also placed at an appropriate location on the lower part of the mold member 22.
7 and 39 are provided.

Spring 35 that biases positioning ring 34
and 36 are springs with a weak biasing force, and when the first outer frame member 23 moves downward and collides with the second outer frame member 24, they contract even with a slight force. The first outer frame member 23 is adapted to abut against the second outer frame member 24. In addition,
In the drawing, only the left and right springs 35 and 36 are shown, but the positioning ring 34
Spring biasing springs are also provided at other suitable locations along the positioning ring 34.
Similarly, springs for biasing the second outer frame member 24 are provided not only at springs 31 and 32 but also at other appropriate locations along the second outer frame member 24. The same applies to the springs 29 and 30 that bias the first mold member 21.

A groove portion 25 is formed inside the lower end surface, which is the abutting surface, of the first outer frame member 23 along the abutting surface. Further, the inner side of the upper end surface, which is the abutting surface of the second outer frame member 24, is also provided so as to face the groove portion 25.
A groove 26 is formed. Note that in the cross-sectional view, the grooves 25 and 26 are illustrated slightly larger for easier viewing.

FIG. 2 is a plan view partially showing the groove portion 26 formed in the abutting surface of the second outer frame member 24. FIG. Further, FIG. 3 is an enlarged perspective view showing the groove portion 26 as well. As shown in FIGS. 2 and 3, the inner wall surface of the groove portion 26 is curved in the direction of curling the outer peripheral portion of the paperboard 60, and furthermore, a guide groove 26a is formed along the curling direction. Paperboard 6
The outer periphery of the paperboard 60 has unevenness due to folding wrinkles, but the outer periphery of the paperboard 60 having such unevenness is guided by the guide groove 26a and curls, so that the folding wrinkles are evenly distributed. Can be curled.

The depth A of the guide groove 26a and the pitch B of the peaks and valleys shown in FIG. 3 are selected as appropriate depending on the size of the paper plate to be formed, the thickness of the paperboard, the shape of the paperboard, etc. In this embodiment, in the paper plate having the shape described below, the depth A of the guide groove 26a is 0.2 to 0.5 mm, and the pitch between the peaks and valleys is B.
is preferably within the range of 0.4 to 1.2 mm. Additionally, a groove 25 formed in the first outer frame member 23
The groove portion 26 is also formed in substantially the same manner as the groove portion 26.

FIG. 4 is a plan view showing an example of an edge-wrapped paper plate formed according to an embodiment of the present invention. Also the fifth
The figure is a sectional view taken along the - line in FIG. 4. The outer periphery of the edge-wrapped paper plate 50 shown in FIGS. 4 and 5 is curled to form an edge wrap 51. Further, fold wrinkles 52 are formed in the portion corresponding to the wall surface which undergoes a large amount of deformation due to the molding process.

FIG. 6 is a plan view showing the paperboard before forming the edge-wrap paper plate shown in FIGS. 4 and 5. FIG. A plurality of filaments 61 are formed on the circular paperboard 60. The filaments 61 are formed by pressing a die onto the paperboard 60 to create a striation with a constant width. When this paperboard 60 is pressed and formed into a predetermined shape as shown in FIGS. 4 and 5, fold wrinkles 52 are formed along the filaments 61. FIG. 7 shows a cross-sectional view of the fold wrinkle 52 taken along the - line shown in FIG. 4. As shown in FIG. 7, the fold wrinkles 52 of the paper plate 50 are fold wrinkles formed in a slightly bulged shape. This is accomplished by providing a clearance between the mold members used to mold this portion, as will be explained later. By making the fold wrinkles bulge in this way, the fold margin for the wrinkles toward the outer periphery of the paper plate becomes smaller.
The hem-wrapping can be done without forming large wrinkles on the outer periphery where the hem-wrapping is to be done, and the hem-wrapping becomes easier.

Hereinafter, the process of forming an edge-wrapped paper plate from paperboard using the apparatus shown in FIG. 1 will be described.

FIG. 8 is a sectional view showing the state in which the outer peripheral portion of the paperboard is compacted. First, the paperboard 60 is placed on the upper end surface of the second outer frame member 24. At this time, a positioning ring 34 is present around the second outer frame member 24, and the position of the paperboard 60 is determined by this positioning ring 34. Next, the first outer frame member 23 and the first mold member 21 move downward. At this time, the first outer frame member 23 moves vigorously downward, and punches and compacts the outer peripheral part 60a of the paperboard 60 between it and the abutting surface of the second outer frame member 24. The first outer frame member 23 is the second outer frame member 24
However, since the spring 35 that biases the positioning ring 34 has a very weak biasing force, the positioning ring 34 moves downward with a small force.
This does not impede punching performed between the second outer frame member 24 and the abutment surface.

By punching between the abutting surfaces of the first outer frame member 23 and the second outer frame member 24, the outer peripheral portion 60a of the paperboard 60 is compacted and increased in density.

FIG. 9 is a sectional view showing a state in which press working of paperboard has begun. When the first mold member 21 and the first outer frame member 23 are further lowered from the state shown in FIG. The paper plate 60 moved downward, and the second mold member 22 begins to mold the paper plate 60 into a predetermined shape. Due to this lowering, the outer circumferential part 60a of the paper plate 60 gradually comes out from between the first outer frame member 23 and the second outer frame member 24, passes between the grooves 25 and 26, and then passes through the outer frame member. move inside. When the outer peripheral part 60a of the paper plate 60 comes off in this way, the first outer frame member 23 and the second
and the outer frame member 24 directly abut each other. Figure 9 shows
This shows a situation like this.

The first mold member 21 and the first outer frame member 23 further descend, pressing the second outer frame member 24 downward and compressing the spring 31.

FIG. 10 shows a state in which the first die member 21 is further lowered, the paperboard 60 is sandwiched between it and the second die member 22, and the paperboard 60 is pressed into a predetermined shape. This shows the state when curling 60a begins. As shown in FIG. 10, the outer peripheral portion 60a of the paperboard 60 is bent downward along the outer peripheral surface of the second mold member 22 due to the lowering of the first outer frame member 23. .

FIG. 11 is an enlarged cross-sectional view showing the vicinity of the grooves 25 and 26 in FIG. 10. As shown in FIG. 11, when the press working of the paperboard 60 is completed, the outer peripheral part 60a of the paperboard 60 is bent downward to the outer peripheral surface of the second mold member 22, and its tip is connected to the groove part 22. and the groove portion 25. Further, a clearance 22b is formed in a portion of the second mold member 22 corresponding to the side surface of the paper plate. By forming such a clearance 22b, it is possible to form the above-described fold wrinkles 52 in the bulged shape shown in FIG. 7. By forming the wrinkles in this bulging shape, it is possible to reduce the overlap of the wrinkles in the outer circumferential portion 60a, so that so-called wrinkles can be reduced, and the hem-wrapping can be facilitated. Although the formation of such a clearance between mold members is a preferable requirement in the present invention, it does not limit the present invention.

In the state shown in FIGS. 10 and 11, the second
The outer frame member 24 is in contact with the support plate part 33,
The first outer frame member 23 is in a state where it cannot move downward any further. In this state,
The first mold member 21 is urged downward by a spring 29, and the paperboard 60 is pressed into a state due to this urging force.

After the press working is done in this way, the first
The outer frame member 23 moves upward. Since the second outer frame member 24 is urged upward by the spring 31, it moves upward as the first outer frame member 23 rises while maintaining the abutting state with the first outer frame member 23. The first mold member 21 is a spring 2
9, the first
Until the locking portion 23a of the outer frame member 23 comes into contact with the locking portion 21a of the first mold member 21, the state in which the paperboard 60 is sandwiched and pressed with the second mold member 22 is maintained. dripping

In the state shown in FIG.
The edge of 0a is located in the gap between the curl groove formed by the edge 25 and the edge 26.
When the second outer frame member 23 rises, the second outer frame member 2
4 also rises, and paperboard 60 is placed in the curl groove.
The end of the outer periphery of is inserted.

FIG. 12 is a sectional view showing such a state. Guide grooves as shown in FIGS. 2 and 3 are formed in the grooves 25 and 26 constituting the curl groove, and the edge of the outer peripheral portion 60a of the paperboard 60, which has unevenness formed by overlapping fold wrinkles, is formed in the grooves 25 and 26 that constitute the curl groove. The portion is curled in the curl groove along such a guide groove to form an edge wrap. In addition, in this invention,
As shown in Figure 8, the paperboard 6 is
Since the outer periphery 60a of 0 is punched and compacted, the density of the paper at the outer periphery is increased, and when curling in such a curl groove, the edges of the outer periphery may stand up. Moreover, since the surface smoothness is improved, the frictional resistance within the curl groove is reduced, and curling can be performed smoothly.

FIG. 13 shows that the state shown in FIG.
The outer frame member 23 is shown in a raised state, and in this state, the paperboard 6 on which the second mold member 22 is molded
It's starting to move away from 0. Outer periphery 60a of paperboard 60
has been curled within the curl groove formed by the edges 25 and 26, and the formation of the hem has been completed. When the first outer frame member 23 further rises, the locking portion 24a is attached to the second outer frame member 24.
It comes into contact with the locking portion 22a of the second mold member 22 and is locked. In this state, the second outer frame member 24 is restricted from moving upward, and when the first outer frame member 23 further rises, the first outer frame member 23 and the second outer frame member 24 are separated. The formed paperboard 60 is separated from the first mold member 21 and the first outer frame member 23 with the outer circumferential hem resting on the groove 26 of the second outer frame member 24 .

As described above, in this embodiment, the fold wrinkles 52 are formed along the filaments 61 of the paperboard 60, and the paperboard 60 is
is formed into a predetermined shape, and the outer periphery of the paperboard is curled to form a hem 51.

In this embodiment, the first mold member 21 is heated by the heater 38, and the second mold member 22 is heated by the heater 38.
Heating at 7 and 39. Particularly preferably,
The temperature of the first mold member 21 is within the range of 140 to 160°C, and the temperature of the second mold member 22 is within the range of 90 to 130°C.
It is desirable that the temperature of the first mold member 21 is higher than that of the second mold member 22 by about 30°C. By creating a temperature difference between such mold members, it is possible to form the hem wrap more smoothly. this is,
It is thought that by increasing the temperature on the side of the first mold member 21, which is the side that is more deformed due to edge wrapping, it is possible to prevent paper from returning due to repulsion and improve shape retention.

In the apparatus of this embodiment, the first mold member 21 is positioned upward, the second mold member 22 is positioned downward, and the center axis is set in the vertical direction to form a vertical press machine. This is because misalignment between mold members becomes a major problem in the molding of edge-wrapped paper plates, and it is preferable that the accuracy be kept at a maximum of 0.1 mm or less. For this reason, it is not possible to obtain sufficient accuracy with a conventional horizontal press machine in which the center axis is oriented horizontally. The edge-wrapping paper plate forming device of this invention includes:
For these reasons, it is preferable that the pressurizing center axis be vertical. As the pressurizing mechanism, for example, a pin-clutch type mechanical press or a hydraulic clutch-type torque back press can be used. From the standpoint of accuracy and workability, the latter hydraulic clutch type torque back press is more desirable. In addition, the power of the pressure press is approximately 35 to
Approximately 60 tons is preferable.

In the present invention, the dimensions and shape of the edge wrapping, such as the outer diameter, can be appropriately selected depending on the size of the paper plate, the thickness of the paper, the quality of the paper, etc. In the case of a paper plate as shown in FIG. 4, the outer diameter can be set to, for example, about 1.5 to 3 mm, taking into account the strength of the paper plate and the volume when the paper plates are stacked.

The paper material of the edge-wrapped paper plate formed in this invention is not particularly limited, but general paperboard such as white paperboard, coated paperboard, card paper, manila paperboard, ivory paper, etc. may be used. I can do it. Furthermore, lower grade paper made of waste paper may be used for the middle layer of the paper. Furthermore, those paperboards,
Laminated products such as aluminum foil or resin film, or resin-coated paperboard can be used.
Further, the thickness of the paper is not particularly limited, but for example, a thickness in the range of 200 g/m ² to 400 g/m ² can be used.

Further, the number of filaments formed on the paperboard is not particularly limited, and can be appropriately selected in consideration of the diameter and rising angle of the paper plate to be formed, the shape of the paper plate to be formed, etc. For example, for a circular plate, 15 to 120 pieces would be the normal range.
Also, the filaments are formed in a roughly radial pattern on the paperboard, but the term "approximately radial" here is not a strict one;
It suffices if it is formed approximately in the direction from the inside to the outside. That is, depending on the shape of the paper plate to be molded, the striations may be provided in the portion where fold wrinkles are most desired to be formed.

Furthermore, although a circular paper plate is illustrated in the embodiment, the paper plate formed by the present invention is not limited to a circular shape, and paper plates of various shapes such as an oval, an ellipse, and a substantially rectangular shape can be formed. It can be applied to

[Effects of the Invention] As explained above, according to the forming method of claim 1 and the forming device of claim 2, the outer peripheral portion of the pre-compacted paperboard is formed into a curl groove having a guide groove along the curling direction. The paper is inserted into the paper and curled to form a hemline. The outer periphery is compacted in advance to increase the density of the paper, so when inserted into the curl groove,
The edge of the outer circumferential part does not stand up and slides smoothly on the inner circumferential wall of the curl groove and is curled. In addition, since a guide groove is formed in the curl groove, the outer periphery of the paperboard, which has irregularities due to fold wrinkles, is curled along this guide groove, and the curl is done with the fold wrinkles evenly distributed throughout. can be done. For this reason, it is possible to prevent wrinkles from overlapping and becoming too thick at the outer periphery and clogging the curl groove.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention. FIG. 2 is a plan view showing a groove formed in the abutting surface of the outer frame member. FIG. 3 is an enlarged perspective view showing a groove formed in the abutting surface of the outer frame member. FIG. 4 is a plan view showing an example of an edge-wrapped paper plate formed according to an embodiment of the present invention. FIG. 5 is a sectional view taken along the - line in FIG. 4.
FIG. 6 is a plan view showing the paperboard before forming. FIG. 7 is a sectional view taken along the - line in FIG. 4,
It is a figure which shows the state of the fold wrinkle of the paper plate shape|molded by Example. FIG. 8 is a cross-sectional view showing the state in which the outer periphery of paperboard is compacted in an embodiment of the present invention. FIG. 9 is a sectional view showing a state in which press working of paperboard has begun in an embodiment of the present invention. FIG. 10 is an end view showing a state when curling of the outer periphery of the paperboard is started in the embodiment of the present invention. FIG. 11 is an enlarged sectional view of FIG. 10. FIG. 12 is a sectional view showing a state in which the outer peripheral portion of paperboard is being curled in an embodiment of the present invention. FIG. 13 is an enlarged sectional view showing the state after the outer peripheral portion of the paperboard has been curled in the embodiment of the present invention. Figure 14 shows
FIG. 1 is a sectional view showing a conventional apparatus for forming paper plates without edge wrapping. FIG. 15 is an end view of a conventional paper plate without edge wrapping. In the figure, 21 is the first mold member, 22 is the second mold member.
23 is a first outer frame member, 24 is a second outer frame member, 21a to 24a are locking parts, 24b, 2
4c is a spring receiving part, 25 and 26 are groove parts, 26
a is a guide groove, 27 and 28 are pedestal parts, 29 to 32 are springs, 33 is a support plate part, 34 is a positioning ring, 35 and 36 are springs, 37, 38, 3
9 is a heater, 50 is an edge-wrapping paper plate, 51 is an edge-wrapper,
52 indicates fold wrinkles, 60 indicates paperboard, and 61 indicates lines.

Claims (1)

[Scope of Claims] 1. Pressing a paperboard on which a plurality of substantially radially extending filaments are formed, folding and wrinkles along the filaments to form the paperboard into a predetermined shape, and forming the paperboard into a predetermined shape. A method for forming an edge-wrapped paper plate by curling the outer periphery to form an edge, the method comprising: tamping the outer periphery of the paperboard; The wall surface is curved in the curling direction, and the outer periphery of the compacted paperboard is inserted into a curl groove having a guide groove along the curling direction and curled to form an edge wrap. How to form a plate. 2 Pressing a paperboard on which a plurality of substantially radially extending filaments are formed, folding and forming wrinkles along the filaments to form the paperboard into a predetermined shape, and curling the outer periphery of the paperboard. A device for forming an edge-wrapped paper plate that forms an edge, comprising: a pair of die members for forming the paperboard into the predetermined shape by sandwiching and pressing the paperboard; and a pair of outer frame members provided so as to abut each other during press working, and abutment surfaces facing each other are provided inside the abutment surfaces of the pair of outer frame members. An annular groove is formed along the curve, the inner wall surface of the groove is curved in the curling direction, and has a guide groove along the curling direction, and each groove is formed so that when the outer frame members collide with each other, the grooves are curved in the curling direction. The outer periphery of the paperboard is clamped by the pair of outer frame members and compacted by the pair of mold members. After the paperboard is pressed into a predetermined shape, the outer periphery of the compacted paperboard is inserted into the curl groove formed by abutting the pair of outer frame members and curled to form an edge. A device for forming edge-wrapped paper plates.