JP6792407B2 - Paper container molding method and molding equipment - Google Patents

Description

The present invention relates to a paper container molding method and a molding apparatus, and more particularly to a paper container molding method and a molding apparatus by press molding.

Conventionally, paper containers have been widely used in the field of packaging containers, and paper containers used for storing frozen foods, containers for range cooking, dishes for serving after cooking, and the like are known.
Further, as a method for forming a paper container whose production quality is stable, a production method and a production apparatus for forming a paper container by press-molding a base paper with a core and a cavity as described below are known.

Patent Document 1 describes a step of supplying a strip-shaped base paper, a step of forming a ruled line for absorbing wrinkles during molding at a corresponding position of the base paper, and a step of transferring the base paper to which the ruled line is formed and transferred. A paper container comprising a step of continuously punching a blank sheet having a desired shape including at least a part of a ruled line and a step of press-molding each of the punched blank sheets at that position. The manufacturing method and manufacturing apparatus of the above are disclosed.
In addition, the paper container manufacturing apparatus forms a ruled line for absorbing wrinkles during molding at a corresponding position of the base paper supply means for supplying the strip-shaped base paper and the supplied base paper, and then transfers the ruled line. It is composed of a means, a blank sheet punching means for punching a blank sheet having a desired shape including at least a part of a ruled line from the transferred base paper, and a pressing means for press-molding the punched blank sheet at that position. It is a thing.
With this configuration, the blank sheet is press-molded as it is at the punched position from the strip-shaped base paper, so that the misalignment can be suppressed as compared with the case where the blank sheet is transferred to the press position after punching, and the manufacturing quality is improved. It will be stable.
In addition, since ruled lines are formed on the blank sheet, wrinkles that are randomly generated on the surface of the blank sheet compressed during press molding can be absorbed by the irregularities formed along the ruled lines, and further, the paper container can be used. The manufacturing quality can be stabilized.

Japanese Unexamined Patent Publication No. 2014-111391

However, the conventional manufacturing method and manufacturing apparatus for a paper container manufactured by press-molding a blank sheet punched from a strip-shaped base paper of Patent Document 1 are performed after press-molding by a core and a cavity which are molding molds for press-molding. By pulling the outer peripheral portion of the blank sheet toward the center of the blank sheet corresponding to the bottom of the paper container, the material is collected and formed, but there are many contact points between the blank sheet before press molding and the molding die. Therefore, the material is not sufficiently collected near the center of the blank sheet, and there is a risk that the bottom surface and the wall portion of the paper container after press molding may be locally thinned or torn, resulting in molding defects.
Further, it is effective to provide unevenness on the bottom surface of the paper container in order to suppress deformation of the bottom surface when the paper container is used. However, in the method and apparatus for manufacturing the paper container of Patent Document 1, a large tension is applied to the blank sheet. Since the outer peripheral portion of the blank sheet is pulled in toward the center of the blank sheet while applying force, it is difficult to sufficiently collect the material for providing unevenness on the bottom of the paper container, and there is a risk of molding defects. was there.
In addition, if the arc of the outer peripheral edge where the tubular wall starts to rise is formed small, which is the connection position between the bottom surface and the wall of the paper container, the amount of material collected from the outer peripheral edge to the bottom surface side before press molding is reduced. , There was a risk of molding defects.

The present invention solves these problems, and with a simple configuration, the material can be sufficiently collected near the center of the blank sheet corresponding to the bottom of the paper container, and tears and molding defects occur. It is an object of the present invention to provide a molding method and a molding apparatus for a paper container without a paper container.

The method for molding a paper container of the present invention is for molding a paper container having a bottom surface having irregularities and a tubular wall portion rising from the bottom surface, and a cavity for molding the outer surface of the paper container and the said. The circumference of the flat base paper placed between the core forming the inner surface of the paper container was held down, and the cavity and the core were relatively moved in the approaching direction to pull in the base paper while deforming it from the surroundings. A method of molding a paper container in which the deformed base paper is sandwiched between the core and the cavity and further compression-molded. The core is provided with an inner bottom surface forming portion and an inner wall surface forming portion. inner bottom forming portion, said inner wall forming portion relatively drivable configured to the cavity direction, after holding the base paper, by the inner bottom surface forming portion, and pushed out the sheet to the cavity direction, While sandwiching the base paper between the inner bottom surface forming portion and the cavity, the inner bottom surface forming portion is moved in a direction of separating from the cavity immediately before compression molding accompanied by uneven molding of the bottom surface of the paper container. Is the solution.
The molding apparatus for molding a paper container of the present invention is a molding apparatus for molding a paper container having an uneven bottom surface and a tubular wall portion rising from the bottom surface, and the molding apparatus is a flat plate. The core has a core that presses the shaped base paper to form the inner surface of the paper container, a cavity that presses the base paper to form the outer surface of the paper container, and a base paper holder that holds the periphery of the base paper. It has an inner bottom surface forming portion and an inner wall surface forming portion, and the inner bottom surface forming portion is configured to be able to form irregularities on the bottom surface, and is separated from the inner wall surface forming portion and relatively front and back in the cavity direction. The cavity is configured to be driveable and to release the pressing force on the base paper, and the cavity is configured to be driveable back and forth relative to the core direction, thereby solving the above-mentioned problems.

According to the method for forming a paper container according to claim 1, the inner bottom surface forming portion of the core is configured to be driveable relative to the inner wall surface forming portion in the cavity direction, and after holding the base paper, the inner bottom surface forming portion is used. By extruding the base paper toward the cavity, the process proceeds with the base paper pulled out excessively, so that the material can be sufficiently collected near the center of the blank sheet corresponding to the bottom of the paper container.
In addition, since the base paper does not come into close contact with the inner wall surface forming portion, it can be pulled into the cavity side without giving a large tensile force to the base paper as compared with the case where the base paper is in close contact with the inner wall surface forming portion, and the bottom surface of the paper container can be drawn. Can supply the materials necessary for the formation of.
Further, when the press-molded paper container sticks to the core, the paper container can be easily removed from the core by moving the inner bottom surface forming portion toward the cavity.
Further, since the inner bottom surface forming portion is moved toward the inner wall surface forming portion immediately before the compression molding accompanied by the uneven molding of the bottom surface of the paper container while sandwiching the base paper between the cavity and the inner bottom surface forming portion, the inner bottom surface forming portion is moved from the inner bottom surface forming portion side. Press molding of the bottom surface of the paper container can be performed with the tensile force on the base paper weakened, which can prevent molding defects and weaken the tensile force on the base paper, which is necessary for forming the bottom surface of the paper container. The material can be drawn in more, and even a paper container with a complicated bottom shape can be prevented from tearing or molding defects.

According to the second aspect of the present invention, the base paper is pulled in while the outer bottom surface forming portion protrudes from the outer wall surface forming portion toward the core, and the base paper is sandwiched between the outer bottom surface forming portion and the inner bottom surface forming portion. By sandwiching the base paper between the outer bottom surface forming portion and the inner bottom surface forming portion in a state where there are few contact points with the core and the cavity, the misalignment of the base paper can be suppressed.
Further, immediately before, immediately after, or at the same time when the inner bottom surface forming portion is moved away from the cavity , the outer bottom surface forming portion moves relatively in the direction of separating from the core, so that the core and the entire cavity sandwich the base paper almost at the same time. It is possible to supply the material necessary for forming the entire paper container without giving a large tensile force to the base paper, and it is possible to prevent molding defects of the paper container.
Further, when the press-molded paper container sticks to the cavity, the paper container can be easily removed from the cavity by moving the outer bottom surface forming portion toward the core.

According to the molding apparatus for molding the paper container according to claim 3 , the core has a core, a cavity, and a base paper holder, and the core has an inner bottom surface forming portion and an inner wall surface forming portion, and the inner bottom surface forming portion. Is configured to be detached from the inner wall surface forming portion and can be driven back and forth relatively in the cavity direction and to release the pressing force on the base paper, so that the tensile force applied to the base paper is weakened immediately before the bottom surface is formed. The bottom surface of the paper container can be press-molded to prevent molding defects, and the tensile force on the base paper is weakened, so that the material required to form the bottom surface of the paper container can be drawn in more, which is complicated. Even a bottom-shaped paper container can prevent tearing and molding defects.
Further , since the cavity is configured to be relatively driveable back and forth in the core direction, the process can be advanced in a state where the base paper is pulled out excessively by pushing the base paper toward the cavity at the inner bottom surface forming portion.
Therefore, the material necessary for forming the bottom surface of the paper container can be supplied without giving a large tensile force to the base paper, and the molding defect of the paper container can be prevented.
Further, when the press-molded paper container sticks to the core, the paper container can be easily removed from the core by moving the inner bottom surface forming portion toward the cavity.

According to the configuration according to claim 4 , since the outer bottom surface forming portion is configured to be detached from the outer wall surface forming portion and can be relatively driven back and forth in the core direction, the outer bottom surface forming portion is formed by the outer wall surface forming portion. By sandwiching the base paper between the outer bottom surface forming portion and the inner bottom surface forming portion while pulling in the base paper while protruding from the core toward the core, the base paper can be moved between the outer bottom surface forming portion and the inner surface while there are few contact points between the base paper and the core and the cavity. It can be sandwiched between the bottom surface forming portion and the misalignment of the base paper can be suppressed.
Further, immediately before, immediately after, or at the same time as the inner bottom surface forming portion moves away from the cavity , the outer bottom surface forming portion moves relatively in the direction away from the core, so that the core and the entire cavity simultaneously sandwich the base paper. It is possible to supply a sufficient amount of materials necessary for forming the entire paper container without giving a large tensile force to the base paper, and it is possible to prevent molding defects of the paper container.
Further, when the press-molded paper container sticks to the cavity, the paper container can be easily removed from the cavity by moving the outer bottom surface forming portion toward the core.
According to the configuration according to claim 5 , since an air cylinder is provided as a drive unit in the inner bottom surface forming portion, the timing, pressure, and speed can be easily adjusted by changing the setting of the air cylinder. Therefore, by adjusting the moving distance of the inner bottom surface forming portion and the pressure adjustment when sandwiching the base paper between the inner bottom surface forming portion and the outer bottom surface forming portion, it is possible to optimally correspond to containers of various shapes.

Top view and side sectional view of the paper container 200 press-molded by the paper container molding apparatus 100 according to the embodiment of the present invention. A cross-sectional view of a paper container molding apparatus 100 according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing steps 1 to 4 of a method for molding a paper container according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing steps 5 to 8 of a method for molding a paper container according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing steps 9 to 12 of a method for molding a paper container according to an embodiment of the present invention.

The paper container molding apparatus 100 according to the embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the paper container 200 molded by the paper container molding apparatus 100 according to the embodiment of the present invention has a circular bottom surface 201 and a tubular wall surface 203 rising from the bottom surface 201. The bottom surface 201 is provided with deformation prevention grooves 202 that suppress the deformation of the bottom surface 201 when a heavy object is placed on the paper container 200, radially outward from the center of the bottom surface 201.
Further, at the upper end of the wall surface 203, a curl portion 204 curled outward in the radial direction in a cylindrical shape is formed over the entire circumference.

As shown in FIG. 2, the paper container molding apparatus 100 has an upper unit 110 and a lower unit 120.
The upper unit 110 is provided with an upper frame 111 and a cavity 112 that presses a flat plate-shaped base paper P to form an outer surface of the paper container 200, and the lower unit 120 presses the lower frame 121 and the base paper P. A core 122 forming the inner surface of the paper container 200 and a lower moving member 127 are provided.
The upper frame 111 and the lower moving member 127 are configured to be movable in the vertical direction, and a base paper holder 130 is provided at the lower end of the upper frame 111 and the upper end of the lower moving member 127 so as to approach each other and hold the periphery of the base paper P. Has been done.

The cavity 112 has an outer bottom surface forming portion 113 that forms the outer surface shape of the bottom surface 201 of the paper container 200, and an outer wall surface forming portion 116 that forms the outer surface shape of the wall surface 203 of the paper container 200.
The outer bottom surface forming portion 113 has a recess 114 that forms the outer surface shape of the deformation prevention groove 202, is connected to the upper frame 111 via an outer bottom surface driving air cylinder 115, and can move back and forth in the core 122 direction. It is configured.
Further, the outer wall surface forming portion 116 is urged toward the core 122 by the spring 117.

The core 122 has an inner bottom surface forming portion 123 that forms the inner surface shape of the bottom surface 201 of the paper container 200, and an inner wall surface forming portion 126 that forms the inner surface shape of the wall surface 203 of the paper container 200.
The inner bottom surface forming portion 123 has a convex portion 124 that forms the inner surface shape of the deformation prevention groove 202, is connected to the lower frame 121 via an inner bottom surface driving air cylinder 125, and can move back and forth in the cavity 112 direction. It is configured in.
The base paper holder 130 is provided with a curling member 131 that forms the curl portion 204 of the paper container 200.

Next, a method of molding the paper container 200 according to the embodiment of the present invention using the paper container molding device 100 will be described with reference to FIGS. 3 to 5.
First, as shown in step 1 of FIG. 3, the base paper P cut to a predetermined size for press molding is placed on the lower unit 120 in alignment with the position of the core 122. At this time, the outer bottom surface driving air cylinder 115 urges the outer bottom surface forming portion 113 toward the core 122, and the outer bottom surface forming portion 113 projects toward the core 122 side from the portion adjacent to the outer wall surface forming portion 116. ..
Next, as shown in step 2 of FIG. 3, the upper unit 110 is lowered to bring it into contact with the lower unit 120, the base paper P is held down by the base paper holder 130, and then, as shown in step 3 of FIG. The bottom surface driving air cylinder 125 urges the inner bottom surface forming portion 123 upward, and pushes the base paper P upward together with the inner bottom surface forming portion 123.
At this time, since the force of the inner bottom surface forming portion 123 to push the base paper P upward is stronger than the force of the base paper holder 130 to pinch the base paper P, the base paper P is pushed out to the inner bottom surface forming portion 123, so that the base paper holder 130 side. The material is drawn into the cavity 112.

Further, as shown in step 4 of FIG. 3, when the upper unit 110 is pushed down, the lower moving member 127 also moves downward, so that the core 122 moves relatively toward the cavity 112. Therefore, the base paper P receives a force further pushed toward the cavity 112 by the inner bottom surface forming portion 123. At this time, since the base paper P is pushed out by moving so that the inner bottom surface forming portion 123 is separated from the inner wall surface forming portion 126, the base paper P has a contact point with the core 122 and the cavity 112 in addition to the inner bottom surface forming portion 123. Since the amount can be reduced, the base paper P does not receive extra frictional resistance, and more material can be drawn into the cavity 112, particularly toward the outer bottom surface forming portion 113 side.

When the upper unit 110 is further pushed down, the base paper P is sandwiched between the outer bottom surface forming portion 113 and the inner bottom surface forming portion 123 as shown in step 5 of FIG. It should be noted that the inner bottom surface driving air cylinder 125 is set in advance to push out the inner bottom surface forming portion 123 with a stronger force than the outer bottom surface driving air cylinder 115, or the urging force of the outer bottom surface driving air cylinder 115 is adjusted at the same timing. By lowering the outer bottom surface forming portion 113, the outer bottom surface forming portion 113 is pushed back upward, and the inner bottom surface forming portion 123 moves to a position where the outer wall surface forming portion 116 sandwiches the inner bottom surface forming portion 123 and the base paper P.

After that, the inner bottom surface driving air cylinder 125 is urged downward and the inner bottom surface forming portion 123 is pulled back in the direction of detaching from the cavity 112 to once remove the tensile force applied to the base paper P.
Next, by lowering the cavity 112, as shown in step 6 of FIG. 4, the base paper P is sandwiched between the cavity 112 and the inner bottom surface forming portion 123, and the bottom surface 201 of the container begins to be molded. In this way, the tensile force applied to the base paper P immediately before molding the bottom surface 201 of the container is once removed, and then the base paper P is sandwiched between the cavity 112 and the inner bottom surface forming portion 123 to form the bottom surface 201 of the base paper P. Since the material tends to collect in the vicinity, even when the bottom surface 201 is provided with the deformation prevention groove 202 having irregularities, the base paper P can be molded without tearing.

When the upper unit 110 is further pushed down in this state, as shown in step 7 of FIG. 4, the entire cavity 112 is pushed down by the upper frame 111, and the portion sandwiched between the core 122 and the cavity 112 of the base paper P is substantially located. At the same time, the base paper P is press-molded, and the base paper P is pulled out from the base paper holder 130 and completely drawn to the side surface of the inner wall surface forming portion 126. At this time, neither the outer bottom drive air cylinder 115 nor the inner bottom drive air cylinder 125 generates a force.
In this way, by moving the outer bottom surface forming portion 113 and the inner bottom surface forming portion 123 immediately before sandwiching the base paper P into the container shape, the core 122 and the entire cavity 112 can sandwich the base paper P at almost the same time, and the base paper P can be sandwiched. The material necessary for forming the entire paper container 200 can be supplied without giving a large tensile force to the paper container 200, and the bottom surface and the wall portion of the paper container 200 are locally thinned or torn during the subsequent press molding. Molding defects can be prevented.
After press molding, the lower moving member 127 is moved upward. As a result, when the upper frame 111 and the curling member 131 are moved upward so as to be pushed up by the lower moving member 127, the outer peripheral edge of the base paper P enters the curling member 131, and as shown in step 8 of FIG. 4, the upper unit The curl portion 204 is formed in accordance with the movement of 110.

At this time, the outer bottom surface driving air cylinder 115 does not urge the outer bottom surface forming portion 113, and only the outer wall surface forming portion 116 is urged downward by the spring 117. Therefore, as the upper unit 110 moves upward, the outer bottom surface forming portion 116 is urged downward. As shown in step 9 of FIG. 5, the outer bottom surface forming portion 113 is separated from the press-formed base paper P (paper container 200).
With the upper unit 110 sufficiently moved upward and the upper unit 110 and the lower unit 120 separated from each other, the outer bottom surface forming portion 113 is moved downward by the outer bottom surface driving air cylinder 115 as shown in step 10 of FIG. When urged, as shown in step 11 of FIG. 5, the outer bottom surface forming portion 113 is shown in step 12 of FIG. 5 by separating the press-formed base paper P (paper container 200) from the outer wall surface forming portion 116. As described above, the press-molded base paper P (paper container 200) can be easily taken out from the cavity 112.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible.
In the above-described embodiment, the paper container has been described as having a circular bottom surface and an outer peripheral surface, but the shape of the paper container is not limited to this, and for example, a part of the outer peripheral surface of the bottom surface is linear. It may be formed so that a part of the outer peripheral surface may be formed so as to project outward in a radial direction in a flange shape.
Further, in the above-described embodiment, it has been described that the deformation prevention grooves protruding from the outer surface side of the bottom surface are provided radially outward from the center of the bottom surface, but the shape of the deformation prevention groove is the same. The present invention is not limited, and for example, it may be provided in a spiral groove shape protruding toward the inner surface side of the bottom surface, or may not have a deformation prevention groove.

Further, in the above-described embodiment, when the base paper is pulled into the cavity from the base paper holder, the inner bottom surface forming portion is urged upward by the inner bottom surface driving air cylinder, and the base paper is pushed upward together with the inner bottom surface forming portion. However, the procedure for pulling the base paper into the cavity is not limited to this. For example, the base paper is held by the base paper holder at the same height as the inner bottom surface forming portion urged in the cavity direction in advance, and then the cavity is inserted together with the base paper holder. By moving the base paper toward the bottom surface forming portion, the base paper may be relatively drawn into the cavity while being pressed against the inner bottom surface forming portion, and further, the inner bottom surface forming portion is moved to the cavity side by the inner bottom surface driving air cylinder and the cavity is moved. The base paper may be pulled into the cavity by moving it toward the inner bottom surface forming portion.
Further, in the above-described embodiment, it has been described that the base paper cut to a predetermined size for press molding is supplied, but the state at the time of supplying the base paper is not limited to this, and for example, the outer circumference of the base paper holder. A cutter may be provided on the surface, and the strip-shaped base paper continuously supplied to the paper container molding apparatus may be cut to a predetermined size for press molding by the cutter while being held by the base paper holder.
Further, in the above-described embodiment, the outer bottom surface forming portion and the inner bottom surface forming portion are urged by an air cylinder, and the outer wall surface forming portion is urged by a spring, but the urging method is limited to this. Instead, for example, a hydraulic cylinder may be used for urging, or a servomotor and a slider may be used for positioning control to move each part.

Further, in the above-described embodiment, the cavity is described as being composed of an outer bottom surface forming portion and an outer wall surface forming portion provided as separate bodies, but the configuration of the cavity is not limited to this, and for example, the outer surface is formed. The bottom surface forming portion and the outer wall surface forming portion may be integrally formed, or an outer peripheral edge forming portion may be provided as a separate body between the outer bottom surface forming portion and the outer wall surface forming portion.
Further, in the above-described embodiment, it has been described that the lower moving member is configured to be movable in the vertical direction, but the configuration of the lower unit is not limited to this, for example, the lower moving member is fixed in position and the entire core. May be configured to be movable in the vertical direction relative to the lower moving member.

100 ・ ・ ・ Paper container molding device 110 ・ ・ ・ Upper unit 111 ・ ・ ・ Upper frame 112 ・ ・ ・ Cavity 113 ・ ・ ・ Outer bottom surface forming part 114 ・ ・ ・ Recessed surface 115 ・ ・ ・ Outer bottom drive air cylinder 116 ・ ・・ Outer wall surface forming part 117 ・ ・ ・ Spring 120 ・ ・ ・ Lower unit 121 ・ ・ ・ Lower frame 122 ・ ・ ・ Core 123 ・ ・ ・ Inner bottom surface forming part 124 ・ ・ ・ Convex part 125 ・ ・ ・ Inner bottom drive air cylinder 126 ・ ・ ・ Inner wall surface forming part 127 ・ ・ ・ Lower moving member 130 ・ ・ ・ Base paper holder 131 ・ ・ ・ Curling member 200 ・ ・ ・ Paper container 201 ・ ・ ・ Bottom surface 202 ・ ・ ・ Deformation prevention groove 203 ・ ・ ・ Wall surface 204 ・ ・ ・ Curling part

Claims (5)

A paper container having a bottom surface having irregularities and a tubular wall portion rising from the bottom surface is molded.
The circumference of the flat base paper placed between the cavity for forming the outer surface of the paper container and the core for forming the inner surface of the paper container is suppressed, and the cavity and the core are relatively moved in the approaching direction. A method for forming a paper container in which the deformed base paper is sandwiched between the core and the cavity after the base paper is pulled in while being deformed from the surroundings, and further compression-molded.
The core is provided with an inner bottom surface forming portion and an inner wall surface forming portion.
The inner bottom surface forming portion is configured to be driveable relative to the inner wall surface forming portion in the cavity direction.
After holding the base paper, by the inner bottom surface forming portion, and pushed out the sheet to the cavity direction,
The base paper is sandwiched between the inner bottom surface forming portion and the cavity, and the inner bottom surface forming portion is moved in a direction of being separated from the cavity immediately before compression molding accompanied by uneven molding of the bottom surface of the paper container. , A molding method for molding a paper container. The cavity is provided with an outer bottom surface forming portion and an outer wall surface forming portion.
While pulling in the base paper while the outer bottom surface forming portion protrudes from the outer wall surface forming portion toward the core, the base paper is sandwiched between the outer bottom surface forming portion and the inner bottom surface forming portion.
The first aspect of the present invention is characterized in that the outer bottom surface forming portion moves relatively in the direction of detaching from the core immediately before, immediately after, or at the same time as moving the inner bottom surface forming portion in the direction of detaching from the cavity. A molding method for molding the described paper container. A molding apparatus for molding a paper container having a bottom surface having irregularities and a tubular wall portion rising from the bottom surface.
The molding apparatus has a core that presses a flat base paper to form an inner surface of a paper container, a cavity that presses the base paper to form an outer surface of a paper container, and a base paper holder that holds the periphery of the base paper. And
The core has an inner bottom surface forming portion and an inner wall surface forming portion.
The inner bottom surface forming portion is configured to be capable of forming irregularities on the bottom surface, is detached from the inner wall surface forming portion, can be relatively driven back and forth in the cavity direction, and can release the pressing force on the base paper. Ori,
A molding apparatus for molding a paper container, wherein the cavity is configured to be relatively driveable back and forth in the direction of the core. The cavity has an outer bottom surface forming portion and an outer wall surface forming portion.
The molding apparatus for molding a paper container according to claim 3 , wherein the outer bottom surface forming portion is configured to be detached from the outer wall surface forming portion so as to be relatively front-rear and backward driveable in the core direction. .. The molding apparatus for molding a paper container according to claim 3 or 4 , wherein an air cylinder is provided as a drive portion in the inner bottom surface forming portion.

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