JP7553071B2 - Manufacturing method of laminated pulp container and manufacturing device of laminated pulp container - Google Patents

Description

The present invention relates to a method and an apparatus for manufacturing laminated pulp containers used for storing food, etc.

A method for manufacturing a laminated pulp container consisting of a laminate of a pulp layer and a plastic layer is known (for example, Patent Document 1). In the manufacturing method of Patent Document 1, the pulp layer is first paper-formed from a raw material liquid containing pulp fibers into a shape with a recess capable of containing contents. After that, a laminate film is placed along the inner surface of the recess, and the pulp layer is vented from the outside to bring the laminate film into close contact with the pulp layer. The laminated pulp container is completed by further adhering the film to the pulp layer. By providing a plastic layer on the inner surface of the recess, the inner surface of the recess can be made water-resistant and oil-resistant, making it possible to contain food, etc., in the recess.

JP 2007-30925 A

In laminated pulp containers manufactured by the method described in Patent Document 1, no laminate film is provided on the outer surface, so the pulp layer is exposed on the outer surface. Therefore, when two laminated pulp containers are stacked one on top of the other, there is a risk that the pulp fibers contained in the pulp layer of the upper container will migrate to the surface of the plastic layer provided in the recess of the lower container. Since such migration of pulp fibers reduces the cleanliness of the plastic layer surface, it is desirable to adhere a laminate film to the outer surface of the pulp layer as well.

Therefore, it is conceivable to follow the method described in Patent Document 1 and then attach a laminate film to the inner surface of the recess, place a new laminate film along the outer surface of the pulp layer, and evacuate the pulp layer from the inner surface of the recess to bring the laminate film into close contact with the outer surface of the pulp layer. However, because the laminate film has poor breathability, it is difficult to evacuate the pulp layer from the inner surface of the recess after attaching the laminate film to the inner surface of the recess, and it is not easy to attach the laminate film to the outer surface of the pulp layer.

The problem that this invention aims to solve is to provide a method and an apparatus for manufacturing laminated pulp containers that enable a laminate film to be bonded to both sides of the container.

The method for manufacturing a laminated pulp container (1) according to the present invention includes a first step (ST1 to ST7) of attaching a first laminate film (12) to one of the inner and outer surfaces of a concave container body (10) made of pulp fibers, and a second step (ST11 to ST16) of attaching a second laminate film (14) to the other of the inner and outer surfaces. The second step includes a supporting step (ST12) of supporting the container body to which the first laminate film has been attached on one of a pair of mold bodies corresponding to the container body, an arrangement step (ST13) of arranging the other of the mold bodies so that the other of the mold bodies faces the other surface of the container body via the second laminate film, and an adhesion step (ST14) of adhering the second laminate film to the container body by the other of the mold bodies.

According to this configuration, the second laminate film is pushed out onto the container body by the mold, and the second laminate film is adhered to the container body. Therefore, since it is not necessary to ventilate the container body to attach the laminate film, it is possible to adhere the laminate film to both sides of the container.

In the above embodiment, more preferably, in the bonding step, gas is blown in a direction in which the second laminate film faces the other surface of the container body.

With this configuration, the second laminate film moves toward the container body when gas is blown onto it. This makes it easier for the second laminate film to adhere to the container body.

In the above embodiment, more preferably, in the first step, the first laminate film is attached to the inner surface, the other of the mold body has a recess and is a female mold having an introduction hole that communicates with the inside of the recess from the outside and opens at the bottom surface of the recess, and in the bonding step, the gas is introduced from the introduction hole between the other of the mold body and the second laminate film, thereby blowing the gas onto the second laminate film.

According to this configuration, by introducing gas from the bottom surface of the recess of the mold body, a gas flow can be generated so that the gas flows out of the recess. This allows the second laminate film to be blown toward the container body, and the second laminate film can be moved toward the container body.

In the above embodiment, more preferably, in the bonding step, the other side of the mold body is brought into contact with the second laminate film to form a sealed space between the other side of the mold body and the second laminate film, and the gas is introduced into the sealed space through the introduction hole to increase the internal pressure of the sealed space.

According to this configuration, when the container body and the second laminate film come into contact with each other, the second laminate film is pressed against the container body by the gas trapped in the sealed space. This causes the second laminate film to be pressed more strongly against the container body, thereby improving the adhesion between the second laminate film and the container body.

In the above embodiment, more preferably, a heating step of heating the second laminate film is included before the positioning step, and the gas is heated before being blown onto the second laminate film in the adhesion step.

With this configuration, the second laminate film becomes more easily deformed by heating, which improves the adhesion between the second laminate film and the container body. Furthermore, because the gas is heated before being blown onto the second laminate film, the second laminate film is less likely to be cooled by the blowing of the gas.

In the above embodiment, more preferably, an elastically deformable elastic member is provided on the other side of the mold body, and the elastic member is pressed against the container body in the bonding step.

With this configuration, when the mold body is pressed against the container body from the other side, the elastic member elastically deforms to match the shape of the container body, thereby improving the adhesion between the second laminate film and the container body.

In the above embodiment, more preferably, in the bonding step, when the elastic member is pressed against the container body, air is evacuated between the other of the mold bodies and the second laminate film.

This configuration prevents gas from remaining between the second laminate film and the elastic member. This makes it easier for the elastic member to elastically deform to match the shape of the container body, improving adhesion between the second laminate film and the container body.

The laminated pulp container manufacturing device (1) according to the present invention is a laminated pulp container manufacturing device for manufacturing a laminated pulp container in which a laminate film (12, 14) is attached to both sides of a container body (10) made of paper made of pulp fibers, and includes a pair of mold bodies consisting of a female mold (38) having a recess (38A) and an introduction hole (38E) opening on the bottom surface of the recess, and a male mold (39) having a protrusion (39A) that fits into the recess, and a drive mechanism for fitting the female mold and the male mold together. The apparatus includes a driving device (40), a gas supply device (41) connected to the introduction hole, and a control device (43) capable of controlling the gas supply device and the driving device, and the control device drives the driving device to fit the female mold and the male mold together, while driving the gas supply device to introduce gas from the introduction hole between the mold body and the laminate film, thereby spraying the gas onto the laminate film and bonding the laminate film to the container body.

According to this configuration, the laminate film is pushed out into the container body by the gas between the laminate film and the mold body, and the laminate film is adhered to the container body. Therefore, since it is not necessary to evacuate the container body to attach the laminate film, it is possible to adhere the laminate film to both sides of the container.

In the above embodiment, preferably, the device further includes an exhaust device (42) connected to the inlet.

This configuration prevents gas from remaining between the laminate film and the female mold. This allows the female mold to more reliably press the laminate film against the container body.

In the above embodiment, the female mold is preferably provided with an elastic member that can be elastically deformed.

With this configuration, when the male and female molds are fitted together to bond the laminate film to the container body, the elastic member elastically deforms, allowing the laminate film to be more closely attached to the container body.

In the above embodiment, preferably, the device further includes a film heating device that heats the laminate film, and a gas heating device (45) that is provided in a gas introduction path (41B) that runs from the gas supply device to the introduction hole and heats the gas passing through the gas introduction path.

With this configuration, the laminate film becomes more easily deformed by heating, which improves the adhesion between the laminate film and the container body. Furthermore, because the gas is blown onto the laminate film after being heated, the laminate film is less likely to be cooled by the blowing of the gas.

The present invention provides a method for manufacturing a laminated pulp container that allows a laminate film to be bonded to both sides of the container, and a manufacturing device for a laminated pulp container.

FIG. 1A is a perspective view of a laminated pulp container manufactured according to the manufacturing method of the present invention, and FIG. 1B is a cross-sectional view taken along the line IB-IB. Schematic diagram showing a production unit for carrying out the production method of the present invention. Schematic diagram for explaining a manufacturing process based on the manufacturing method of the first embodiment. An enlarged view of IV in FIG. 1 is a flow chart showing an inner lamination process according to the manufacturing method of the present invention. 1 is a flow chart showing the outer surface lamination process of the manufacturing method according to the present invention. FIG. 13 is a schematic diagram for explaining a manufacturing process based on the manufacturing method of the second embodiment;

Below, an embodiment of the method for manufacturing a laminated pulp container according to the present invention will be described with reference to Figures 1 and 2.

First Embodiment
As shown in Fig. 1(A), a laminated pulp container 1 manufactured by the manufacturing method of the present invention is in the form of a tray having a storage recess 2 for storing food or other contents and a flange 3 on the edge of the opening. As shown in Fig. 1(B), the laminated pulp container 1 is composed of a multilayer structure 5 made of a plurality of layers. More specifically, the laminated pulp container 1 includes a pulp layer 6 made of pulp fibers and having a recess formed on one surface (hereinafter, the inner surface) for defining the storage recess 2, an inner surface laminate layer 7 bonded to the inner surface of the pulp layer 6, and an outer surface laminate layer 8 bonded to the other surface (hereinafter, the outer surface) of the pulp layer 6.

The pulp layer 6 is a sheet member formed into a tray shape, is made of pulp fibers, and is breathable. The pulp layer 6 is produced from a raw material liquid containing pulp fibers by a known method. For ease of explanation, the structure consisting of only the pulp layer 6 will be referred to as the container body 10, and the recess formed in the pulp layer 6 will be referred to as the body recess 11.

The inner laminate layer 7 is formed by attaching an inner laminate film 12 (first laminate film; see FIG. 3), which is a plastic film, to the surface of the container body 10 on which the body recess 11 is formed, i.e., the inner surface. The inner laminate layer 7 covers the entire wall surface of the body recess 11. The outer surface of the container body 10 is provided with a body protrusion 13 that is pushed outward and protrudes outward due to the body recess 11 being provided. The outer laminate layer 8 is formed by attaching an outer laminate film 14 (second laminate film; see FIG. 3), which is a plastic film, to the outer surface of the container body 10 including the body protrusion 13. The outer laminate layer 8 covers the entire outer surface of the container body 10.

Next, the manufacturing unit 20 used in manufacturing the laminated pulp container 1 will be described. As shown in FIG. 2, the manufacturing unit 20 has a known papermaking device (not shown) for papermaking the container body 10 from the raw material liquid, an inner laminating device 21 that attaches the inner laminating film 12 to the inner side of the container body 10, and an outer laminating device 22 that attaches the outer laminating film 14 to the outer side. Below, the inner laminating device 21 and the outer laminating device 22 will be described in detail with reference to FIG. 2.

As shown in FIG. 2, the inner laminating device 21 has a pair of reels 23 that support the inner laminating film 12 wound in a roll, a first transport device 24 that transports the inner laminating film 12, a first heating device 25, a first bonding device 26, and a first cutting device (not shown). The reels 23 are each arranged on a horizontal plane so as to face the first heating device 25, the first bonding device 26, and the first cutting device on either side.

The first transport device 24 pulls out the inner laminate film 12 from the reel 23 (hereafter referred to as the delivery reel 23A) located on the side of the first heating device 25 and winds it up on the reel 23 (hereafter referred to as the take-up reel 23B) located on the side of the first bonding device 26, thereby transporting the inner laminate film 12 while keeping it taut.

The first heating device 25 has two heaters 25A for heating both sides of the inner laminate film 12 and a roller 25B for transporting the inner laminate film 12.

2, the first bonding device 26 includes a pair of a first female mold 28 and a first male mold 29, a first drive unit 30 that moves the first female mold 28 and the first male mold 29 relative to each other, a first exhaust unit 31, and a first control unit 32 that receives input from an operator and controls the first drive unit 30 and the first exhaust unit 31. The first female mold 28 is a stainless steel mold and includes a first cavity 28A that is recessed in a shape corresponding to the main body recess 11. The first female mold 28 is provided with a first air hole 28B that extends from the outer surface to a wall surface (hereinafter, the inner surface) that defines the first cavity 28A and opens on the inner surface.

The first male mold 29 has a first pressing portion 29A having an outer surface shape similar to the inner surface shape of the first cavity 28A. In this embodiment, an elastic member 29B that can be elastically deformed by pressing against the inner surface of the first cavity 28A is provided on the outer surface of the first pressing portion 29A. The elastic member 29B is, for example, a rubber-like member, and more preferably made of silicone rubber. This prevents the elastic member 29B from being deformed or altered by heat from the inner laminate film 12.

Based on a signal from the first control device 32, the first drive device 30 moves the first male mold 29 between a position where the first pressing portion 29A is separated from the first cavity 28A (separation position) and a position where the first pressing portion 29A is inserted into the first cavity 28A and engages with each other (insertion position). In this embodiment, the first male mold 29 is disposed above the first female mold 28, and the first drive device 30 moves the first female mold 28 and the first male mold 29 in the vertical direction to move them between the separation position and the insertion position.

The first exhaust device 31 is connected to the first ventilation hole 28B via a specified pipe 28C. The first exhaust device 31 is driven based on a signal from the first control device 32 and exhausts air from the first ventilation hole 28B.

The first control device 32 is a computer equipped with a central processing unit (CPU) and storage devices such as memory and HDD, and has a first input unit 32A that accepts input from an operator. The first input unit 32A is, for example, a touch panel. Based on the input to the first input unit 32A, the first control device 32 drives the first transport device 24 to transport the inner lamination film 12. Based on the input to the first input unit 32A, the first control device 32 also drives the first drive device 30 to move the first female die 28 and the first male die 29 between the separation position and the insertion position. Based on the input to the first input unit 32A, the first control device 32 also drives the first exhaust device 31 to exhaust air from the first ventilation hole 28B.

The first cutting device cuts the inner laminate film 12 attached to the inner surface of the container body 10. By cutting the inner laminate film 12 with the first cutting device, the container body 10 can be separated from the inner laminate film 12 wound into a roll.

The outer laminating device 22 has a pair of reels 33 that support the outer laminating film 14 wound in a roll, a second transport device 34 that transports the outer laminating film 14, a second heating device 35 (film heating device), a second bonding device 36, and a second cutting device (not shown). The reels 33 are each arranged on a horizontal plane facing each other with the second heating device 35, the second bonding device 36, and the second cutting device in between.

The second transport device 34 transports the outer laminate film 14 while keeping it taut by pulling it out from the reel 33 (hereafter referred to as the delivery reel 33A) located on the side of the second heating device 35 and winding it up on the reel 33 (hereafter referred to as the take-up reel 33B) located on the side of the second bonding device 36.

The second heating device 35 is similar to the first heating device 25 and includes two heaters 35A for heating both sides of the outer laminate film 14 and a roller 35B for transporting the outer laminate film 14.

The second bonding device 36 includes a pair of a second female mold 38 (mold body) and a second male mold 39 (mold body), a second drive device 40 that moves the second female mold 38 and the second male mold 39 relative to each other, a compressed air supply device 41, a second exhaust device 42, and a second control device 43 that receives input from an operator and controls the second drive device 40, the compressed air supply device 41 (gas supply device), and the second exhaust device 42. In this embodiment, the second bonding device 36 further includes a compressed air heater 45 (gas heating device) that heats the compressed air supplied from the compressed air supply device 41.

The second female mold 38 is a mold body having a second cavity 38A, which is a recessed portion recessed upward and has a shape corresponding to the main body protrusion 13. More specifically, the second female mold 38 has a metal base 38B and an elastic member 38C similar to that of the first male mold 29. The base 38B has a base recess 38D recessed upward to form the second cavity 38A, and the elastic member 38C covers the wall surface defining the base recess 38D and the peripheral portion of the opening of the base recess 38D. Thus, at least the wall surface of the second cavity 38A is covered by the elastic member 38C. The elastic member 38C provided in the second female mold 38 may be the same as the elastic member 29B provided in the first male mold 29, and is preferably made of silicone rubber. The second female mold 38 has multiple second air holes 38E that connect the outside to the inside of the second cavity 38A and open at the bottom surface of the second cavity 38A (the surface that defines the upper boundary of the second cavity 38A).

In this embodiment, the second cavity 38A is recessed into a substantially rectangular parallelepiped shape. At least one of the second air vents 38E opens in the approximate center of the bottom surface of the second cavity 38A.

The second male mold 39 is a stainless steel mold having a second pressing portion 39A at the bottom. The second pressing portion 39A has an outer surface shape that matches the inner surface shape of the main body recess 11, and as shown in FIG. 2, has an outer surface shape similar to the inner surface shape of the second cavity 38A.

Based on a signal from the second control device 43, the second drive unit 40 moves the second female die 38 between a position where the second cavity 38A is separated from the second pressing portion 39A (separation position) and a position where the second pressing portion 39A is inserted into the second cavity 38A and they fit together (insertion position). In this embodiment, the second female die 38 is disposed above the second male die 39, and the second drive unit 40 moves the second female die 38 and the second male die 39 in the vertical direction to move them between the separation position and the insertion position.

The compressed air supply device 41 is connected to the second vent hole 38E by a pipe 41A. The compressed air supply device 41 is driven based on a signal from the second control device 43 to supply compressed air into the pipe 41A and release the compressed air from the second vent hole 38E. That is, the pipe 41A defines a compressed air introduction path 41B (gas introduction path) from the compressed air supply device 41 to the inside of the second cavity 38A, and the second vent hole 38E functions as an introduction hole for introducing compressed air into the inside of the second cavity 38A. However, in this embodiment, the compressed air supply device 41 supplies compressed air into the pipe 41A, but it may be any device that supplies compressed gas to the pipe 41A, for example, compressed nitrogen gas may be supplied into the pipe 41A.

The second exhaust device 42 is connected to the pipe 41A via a specific pipe 42A. The second exhaust device 42 is driven based on a signal from the second control device 43 to reduce the pressure in the pipe 41A to atmospheric pressure. The second exhaust device 42 may be a device that opens the pipe 41A to the atmosphere to reduce the internal pressure of the pipe 41A to atmospheric pressure, or may be a pump that forcibly reduces the pressure in the pipe 41A.

The second control device 43, like the first control device 32, is a computer equipped with a central processing unit (CPU) and storage devices such as memory and HDD, and has a second input unit 43A that accepts input from an operator. The second input unit 43A is, for example, a touch panel. The second control device 43 drives the second transport device 34 to transport the outer surface side laminate film 14 based on the input to the second input unit 43A. The second control device 43 also drives the second drive device 40 based on the input to the second input unit 43A to move the second female mold 38 and the second male mold 39 between the separation position and the insertion position. The second control device 43 also drives the second exhaust device 42 based on the input to the second input unit 43A to exhaust air from the second ventilation hole 38E. Furthermore, the second control device 43 drives the compressed air supply device 41 based on the input to the second input unit 43A to release compressed air from the second ventilation hole 38E.

The compressed air heater 45 is a device for heating the compressed air supplied from the compressed air supply device 41 and passing through the compressed air introduction passage 41B, and is provided in the pipe 41A.

The second cutting device cuts the outer laminate film 14 attached to the outer surface of the container body 10. By cutting the outer laminate film 14 with the second cutting device, the container body 10 can be separated from the outer laminate film 14 wound into a roll.

Next, the manufacturing process of the laminated pulp container 1 will be described with reference to Figures 3 to 6. The manufacturing process includes a papermaking process, an inner lamination process (first process, ST1 to ST7 in Figure 5), and an outer lamination process (second process, ST11 to ST16 in Figure 6) in the order described. The papermaking process is a process of papermaking the container body 10 from a raw material liquid containing pulp fibers, and may be based on a known method. The inner lamination process is a process of attaching an inner lamination film 12 to the inner side of the container body 10 after papermaking, and the outer lamination process is a process of attaching an outer lamination film 14 to the outer side of the container body 10 after the inner lamination process is completed. Below, the inner lamination process will first be described with reference to Figures 3 and 5.

In the first step of the inner lamination process (step ST1, see FIG. 5), the worker drives the first transfer device 24 to transfer the inner lamination film 12 between the heaters 25A of the first heating device 25, and heats both sides of the film (see FIG. 3(A)). An adhesive is applied to the back side of the heated inner lamination film 12 (the side that is attached to the container body 10).

Next, the worker positions the container body 10 so that the body protrusion 13 of the container body 10 protrudes downward, and inserts the body protrusion 13 into the first cavity 28A of the first female die 28 to set the container body 10 in the first female die 28 (step ST2). After that, the worker performs a predetermined input to the first input unit 32A to drive the first transfer device 24. As a result, the heated inner laminate film 12 is transferred between the container body 10 and the first male die 29, and the heated inner laminate film 12 is placed between the container body 10 and the first male die 29 (see FIG. 3B; step ST3). At this time, the inner laminate film 12 is held by the pair of reels 23 in a pulled state.

Then, when the worker performs a predetermined input to the first input unit 32A, the first control device 32 causes the first drive device 30 to raise the first female die 28 so that the container body 10 approaches the inner laminate film 12. The first control device 32 then lowers the first male die 29, inserting the first pressing part 29A into the body recess 11 and fitting the first female die 28 and the first male die 29 together (see FIG. 3(C); step ST4).

Then, the first drive unit 30 further lowers the first male mold 29, and the back surface of the inner laminate film 12 contacts the surface (inner surface) of the container body 10 on which the body recess 11 is provided (see FIG. 3(C)). Furthermore, the first control unit 32 drives the first drive unit 30 to lower the first male mold 29, and presses the elastic member 29B against the container body 10 with a predetermined load (see FIG. 3(D); step ST5). At this time, the inner laminate film 12 is pressed by the elastic member 29B against the surface (inner surface) of the container body 10 on which the body recess 11 is provided, and the inner laminate film 12 is pressed against the container body 10. As a result, the inner laminate film 12 is adhered to the container body 10.

After the back surface of the inner laminate film 12 comes into contact with the inner surface of the container body 10, the first control device 32 drives the first exhaust device 31 to exhaust air from the first air vent 28B between the inner laminate film 12 and the container body 10 until the adhesion of the inner laminate film 12 is completed. This reduces the pressure between the inner laminate film 12 and the container body 10. This prevents air from remaining between the inner laminate film 12 and the container body 10 and generating air bubbles, allowing the inner laminate film 12 and the container body 10 to be tightly attached to each other.

After the elastic member 29B is pressed against the inner surface of the container body 10, and a predetermined time has elapsed, the first control device 32 raises the first male die 29 away from the first female die 28 and pulls out the first pressing part 29A from the first cavity 28A (step ST6). The first control device 32 then controls the first cutting device to cut the inner surface laminate film 12 (step ST7). The first control device 32 then stops driving the first exhaust device 31 and ends exhaust from the first air hole 28B. This completes the inner surface lamination process.

The worker then removes the container body 10 with the inner laminating film 12 attached to its inner surface from the inner laminating device 21.

Next, the worker performs the outer lamination process shown in Figures 3, 4, and 6. In the first step of the outer lamination process (step ST11 in Figure 6), the worker drives the second transfer device 34, transfers the outer lamination film 14 between the heaters 35A of the second heating device 35, and heats both sides of the outer lamination film 14 (see Figure 3 (E); hereafter, heating step). An adhesive is applied to the back surface (adhesive surface) of the outer lamination film 14 that is to be heated.

When the heating step is completed, the worker places the container body 10 with the inner laminate film 12 attached to its inner surface so that the body recess 11 faces downward, and places the container body 10 over the second pressing portion 39A of the second male mold 39. This causes the second pressing portion 39A to be inserted into the body recess 11, and the container body 10 that has undergone the inner lamination process is set in the second male mold 39. At this time, the container body 10 with the inner laminate film 12 already attached to its inner surface is supported by the second male mold 39 (step ST12, hereinafter referred to as the supporting step).

When the supporting step is completed, the worker inputs a predetermined input to the second input unit 43A to drive the second transfer device 34. As a result, the heated outer laminate film 14 is transferred between the container body 10 and the second female die 38, and the heated outer laminate film 14 is placed between the container body 10 and the second female die 38 (step ST13, hereinafter referred to as the placing step). At this time, the outer laminate film 14 is held in a pulled state by the pair of reels 33. At this time, the second female die 38 is located on the side of the surface of the outer laminate film 14 (the surface on which the adhesive surface is not provided), and is positioned to face the outer surface of the container body 10 via the outer laminate film 14 and to be aligned.

Furthermore, when the operator inputs to the second input unit 43A, the second control device 43 controls the second drive device 40, the compressed air supply device 41, the second exhaust device 42, and the compressed air heater 45 to perform a bonding step in which the second female mold 38 and the second male mold 39 are engaged to bond the outer laminate film 14 to the container body 10. Details of the bonding step (step ST14) are described below.

In the bonding step, the second control device 43 first drives the second drive device 40 to lower the second female die 38 so that it approaches the surface of the outer laminate film 14. This forms a space S between the second female die 38 and the outer laminate film 14. The space S is connected to the outside via the gap P between the second female die 38 and the outer laminate film 14.

Then, the second control device 43 raises the second male die 39 and inserts the second pressing portion 39A of the second male die 39 into the second cavity 38A. As a result, the outer laminate film 14 is pushed upward by the upper surface (pointed end surface) of the second pressing portion 39A.

During this time, the second drive unit 40 drives the compressed air supply unit 41 and the compressed air heater 45. This introduces heated compressed air into the space S between the outer laminate film 14 and the second female die 38. The introduced compressed air is released into the space S from the second air hole 38E of the second female die 38. The compressed air released into the space S flows toward the gap P (see the arrow in FIG. 3(G)). At this time, the compressed air is blown onto the outer laminate film 14 so that the outer laminate film 14 faces the outer surface of the container body 10. This causes the outer laminate film 14 to be pushed toward the outer surface of the container body 10, and the outer laminate film 14 to move toward the outer surface of the container body 10 (see the dashed arrow in FIG. 4).

In this embodiment, the second air vent 38E opens in approximately the center of the bottom surface of the second cavity 38A, so the compressed air released from the second air vent 38E flows from top to bottom. This flow of compressed air causes the outer surface laminate film 14 to move from top to bottom toward the outer surface of the container body 10. This traps air between the outer surface laminate film 14 and the outer surface of the container body 10, preventing the formation of air bubbles.

The second drive unit 40 further raises the second male die 39 and inserts the second pressing portion 39A of the second male die 39 into the second cavity 38A of the second female die 38, thereby fitting the second female die 38 and the second male die 39 together. Until the second female die 38 and the second male die 39 are fitted together, the air between the outer laminate film 14 and the container body 10 passes through the inside of the container body 10 and is released to the outside from the edge of the container body 10 (see the dashed arrow in FIG. 3(G)).

Then, the second control device 43 controls the second drive device 40 to move the second female die 38 downward, and press the elastic member 38C of the second female die 38 against the container body 10 with a predetermined load (see FIG. 3(H)). At this time, the elastic member 38C of the second female die 38 contacts the outer laminate film 14, and the outer laminate film 14 is pressed against the outer surface of the container body 10 by the elastic member 38C. This makes the outer laminate film 14 more closely adhere to the container body 10. The air located between the outer laminate film 14 and the container body 10 is released to the outside from the edge of the container body 10, preventing air from remaining between the outer laminate film 14 and the outer surface of the container body 10.

When the elastic member 38C of the second female die 38 is pressed against the container body 10 with a predetermined load, the second control device 43 stops the compressed air supply device 41 and drives the second exhaust device 42 to exhaust air. This more reliably prevents air from remaining in the space S, making it easier for the elastic member 38C to deform along the outer surface of the container body 10. This makes it easier for the outer laminate film 14 to be in close contact with the outer surface of the container body 10.

As shown in FIG. 3(H), in this embodiment, the second female die 38 contacts the outer laminate film 14 only at the elastic member 38C. In other words, the portion of the second female die 38 that contacts the outer laminate film 14 is formed by the elastic member 38C.

Next, the second control device 43 presses the elastic member 38C of the second female die 38 against the container body 10 with a predetermined load for a predetermined time, and then moves the second female die 38 upward to separate the second pressing part 39A from the second cavity 38A (step ST15). When separation is complete, the second control device 43 stops the second exhaust device 42. Thereafter, lamination of both the front and back sides is completed, and the excess outer laminate film 14 is cut off by the second cutting device (step ST16), completing the laminated pulp container 1.

The effects of the manufacturing method of the laminated pulp container 1 configured as follows will be explained. By providing the inner laminate layer 7 on the inner surface of the container body 10, the inner surface of the container body 10 can be made water-resistant and oil-resistant. This makes it possible to prevent water and oil from leaking out of the laminated pulp container 1 when food or the like is stored in the storage recess 2.

When shipped or reused, laminated pulp containers 1 may be stacked on top of each other. At this time, the outer surface of the laminated pulp container 1 comes into contact with the inner surface of another laminated pulp container 1. In the laminated pulp container 1 according to the present invention, an outer laminate layer 8 is provided on the outer surface. This prevents adhesion of pulp fibers to the inner surface of another laminated pulp container 1 that contacts its outer surface when the laminated pulp containers 1 are stacked. This prevents a decrease in the cleanliness of the wall surface of the storage recess 2 when the laminated pulp containers 1 are stacked. In addition, moisture and oil adhering to the wall surface of the storage recess 2 can be prevented from adhering to the outer surface of the other laminated pulp containers 1 stacked and seeping into the inside of the container body 10.

Since the laminate film is made of plastic, it has poor breathability. Therefore, it is difficult to ventilate from the inner side of the container body 10 when only the inner laminate film 12 is attached, and it is difficult to attach the outer laminate film 14 to the outer surface of the container body 10. In this embodiment, the outer laminate film 14 is pressed against the outer surface of the container body 10 by the second female die 38 and adhered to the container body 10. Therefore, since it is not necessary to vent the container body 10 to attach the outer laminate film 14, it is possible to adhere the laminate film to both sides of the container body 10.

In this embodiment, compressed air is introduced into the space S between the outer laminate film 14 and the second female die 38, and the outer laminate film 14 moves to the outer surface of the container body 10. This makes it easier for the outer laminate film 14 to fit the outer surface of the container body 10, and makes it easier for the outer laminate film 14 to be adhered to the outer surface of the container body 10.

The second female die 38 is provided with a second vent hole 38E that opens at the bottom surface of the second cavity 38A. This makes it easy to introduce compressed air into the space S between the outer laminate film 14 and the second female die 38. In addition, in this embodiment, the second vent hole 38E is provided at the bottom surface (more preferably, approximately at the center) of the second cavity 38A, so that a flow of compressed air from the top to the bottom, that is, a flow of compressed air in the direction flowing out of the second cavity 38A (see the solid arrow in FIG. 4), is generated. This flow of compressed air allows the outer laminate film 14 to be blown toward the container body 10, and the outer laminate film 14 can be moved toward the container body 10. This makes it easier for the outer laminate film 14 to be adhered to the outer surface of the container body 10. In addition, because the compressed air flows from top to bottom, the outer laminate film 14 is easily adhered from the top, preventing wrinkles, air bubbles, etc. from forming.

The outer laminate film 14 is heated in step ST11. This makes the outer laminate film 14 more easily deformable, making it easier for the outer laminate film 14 to adhere to the container body 10. Furthermore, in this embodiment, the compressed air is blown onto the outer laminate film 14 after being heated. Therefore, the blowing of the compressed air makes it difficult for the outer laminate film 14 to cool, and therefore the adhesion between the outer laminate film 14 and the container body 10 can be improved compared to when the compressed air is not heated.

In this embodiment, in step ST14, the outer laminate film 14 is pressed against the outer surface of the container body 10 by the elastic member 38C of the second female die 38. This makes it possible to more reliably exhaust air between the back surface of the outer laminate film 14 and the outer surface of the container body 10, and to more reliably adhere the outer laminate film 14 to the entire outer surface of the container body 10.

As shown in FIG. 3(H), the portion of the second female die 38 that comes into contact with the outer laminate film 14 is made of an elastic member 38C. The elastic member 38C of the second female die 38 is made of silicone rubber and is elastically deformable, so when the elastic member 38C is pressed against the container body 10, it deforms to match the shape of the container body 10. This makes it less likely for a gap to form between the outer laminate film 14 and the container body 10, improving the adhesion of the outer laminate film 14 to the container body 10.

<<Second embodiment>>
The method for manufacturing the laminated pulp container 1 according to the second embodiment differs from the first embodiment only in the bonding step of the outer laminate film 14, and other parts are the same as those of the first embodiment, so a description thereof will be omitted.

In the bonding step, the second control device 43 first drives the second drive device 40 to lower the second female die 38 and bring it into contact with the surface of the outer laminate film 14 (see FIG. 7A). This forms a space S between the second female die 38 and the outer laminate film 14, and the space S is effectively sealed. This effectively seals the space S to become a sealed space. Here, being effectively sealed means that the internal pressure of the space S becomes higher than the outside air by supplying compressed air to the space S, and does not require that the air flow between the space S and the outside air be completely blocked.

After the second female die 38 is lowered and brought into contact with the surface of the outer laminate film 14, the second control device 43 drives the compressed air supply device 41 and compressed air heater 45 to supply heated compressed air to the space S between the second female die 38 and the outer laminate film 14. This causes the internal pressure of the space S between the second female die 38 and the outer laminate film 14 to rise and become higher than atmospheric pressure.

Next, the second control device 43 drives the second drive device 40 to lower the second female die 38 and push the outer laminate film 14 downward (see FIG. 7(B)). After that, the second control device 43 raises the second male die 39 to engage with the second female die 38 (see FIG. 7(C)). After that, the adhesive step is completed by pressing the elastic member 38C against the outer surface of the container body 10. However, as in the first embodiment, while the elastic member 38C is being pressed against the outer surface of the container body 10, the second control device 43 may drive the second exhaust device 42 to make the internal pressure of the space S atmospheric pressure.

Next, the effect of the manufacturing method of the laminated pulp container 1 configured in this manner will be described. After the second female die 38 comes into contact with the surface of the outer laminate film 14, while it is descending, the space S is maintained at a higher temperature than the outside air. At this time, as shown by the dashed arrow in FIG. 7(B), a load is applied to the outer laminate film 14 so as to expand the space S from the air trapped in the space S. This load presses the outer laminate film 14 more firmly against the outer surface of the container body 10. This allows the outer laminate film 14 to be more strongly pressed against the outer surface of the container body 10. Therefore, the outer laminate film 14 can be attached to the outer surface of the container body 10 with better adhesion.

The present invention has been described above in terms of its preferred embodiments, but as will be readily understood by those skilled in the art, the present invention is not limited to such embodiments and can be modified as appropriate without departing from the spirit of the present invention.

In the above embodiment, a process of attaching the inner laminate film 12 to the inner surface of the container body 10 is followed by a process of attaching the outer laminate film 14 to the outer surface of the container body 10, but this is not limited to the embodiment. A process of attaching the inner laminate film 12 to the inner surface of the container body 10 may be provided after the process of attaching the outer laminate film 14 to the outer surface of the container body 10.

Furthermore, not all of the components shown in the above embodiment are necessarily essential, and they can be selected as appropriate without departing from the spirit of the present invention.

1: Laminated pulp container 2: Storage recess 3: Flange 5: Multilayer structure 6: Pulp layer 7: Inner laminate layer 8: Outer laminate layer 10: Container body 11: Body recess 12: Inner laminate film (first laminate film)
13: Main body convex portion 14: Outer surface side laminate film (second laminate film)
20: Manufacturing unit 21: Inner surface laminating device 22: Outer surface laminating device 23: Reel 23A: Delivery reel 23B: Take-up reel 24: First transfer device 25: First heating device 25A: Heater 25B: Roller 26: First bonding device 28: First female mold 28A: First cavity 28B: First vent hole 28C: Pipe 29: First male mold 29A: First pressing section 29B: Elastic member 30: First drive device 31: First exhaust device 32: First control device 32A: First input section 33: Reel 33A: Delivery reel 33B: Take-up reel 34: Second transfer device 35: Second heating device (film heating device)
35A: heater 35B: roller 36: second bonding device 38: second female mold (the other side of the mold body)
38A: Second cavity (recess)
38B: Base body 38C: Elastic member 38D: Base body recess 38E: Second air hole (introduction hole)
39: Second male mold (one of the mold bodies)
39A: Second pressing unit 40: Second driving device 41: Compressed air supply device (gas supply device)
41A: Pipe 41B: Compressed air introduction path (gas supply path)
42: Second exhaust device 42A: Pipe 43: Second control device 43A: Second input unit 45: Compressed air heater (gas heating device)
P: Gap S: Space ST1: Step ST2: Step ST3: Step ST4: Step ST5: Step ST6: Step ST7: Step ST11: Step (heating step)
ST12: Step (support step)
ST13: Step (placement step)
ST14: Step (adhesion step)
ST15: Step ST16: Step

Claims (9)

The method includes a first step of attaching a first laminate film to an inner surface of a concave container body made of pulp fibers, and a second step of attaching a second laminate film to an outer surface of the container body,
The second step comprises:
a supporting step of supporting the container body to which the first laminate film is attached on a male mold corresponding to the container body;
a positioning step of positioning a female mold that fits into the male mold so as to face the outer surface of the container body via the second laminate film;
and a bonding step of fitting the male mold and the female mold together to bond the second laminate film to the container body,
In the first step, the first laminate film is attached to the inner surface,
the female mold has a recess and an introduction hole that communicates from the outside to the inside of the recess and opens at the center of a bottom surface of the recess,
In the supporting step, the second laminate film is placed between the female mold and the container body in a stretched state,
In the bonding step, gas is introduced between the female mold and the second laminate film from the introduction hole , thereby blowing the gas onto the portion of the second laminate film that is to be bonded to the center of the outer surface of the bottom wall of the container body, and pushing the portion of the second laminate film that is to be bonded to the center of the outer surface of the bottom wall of the container body toward the center of the outer surface of the bottom wall of the container body, while moving the male mold toward the female mold to insert it into the recess of the female mold, thereby adhering the second laminate film to the outer surface of the bottom wall of the container body, and then, while introducing the gas from the introduction hole into the gap between the female mold and the container body, passing through the outer surface of the bottom wall of the container body and the outer surface of the side wall of the container body, and leading to the outside, the male mold is fitted into the female mold, and the second laminate film is bonded to the container body . The method for manufacturing a laminated pulp container according to claim 1, wherein in the bonding step, the female mold is brought into contact with the second laminate film to form a sealed space between the female mold and the second laminate film, and the gas is introduced into the sealed space through the introduction hole to increase the internal pressure of the sealed space. A heating step of heating the second laminating film is included before the placing step,
3. The method for producing a laminated pulp container according to claim 1, wherein the gas is heated before being blown onto the second laminate film in the bonding step. The female mold is provided with an elastic member capable of elastic deformation,
4. The method for manufacturing a laminated pulp container according to claim 1, wherein the elastic member is pressed against the container body in the bonding step. The method for manufacturing a laminated pulp container according to claim 4, wherein, in the bonding step, when the elastic member is pressed against the container body, air is evacuated between the female mold and the second laminate film. A laminated pulp container manufacturing apparatus for manufacturing a laminated pulp container in which a laminate film is attached to both sides of a container body made of pulp fibers, comprising:
A pair of mold bodies including a female mold having a recess and an introduction hole that opens to a bottom surface of the recess, and a male mold having a protrusion that fits into the recess;
a drive device for fitting the female mold and the male mold together;
A gas supply device connected to the inlet;
a control device capable of controlling the gas supply device and the drive device,
The introduction hole is provided at the center of the bottom surface of the female mold,
The container body is supported by the male mold, and the laminate film is arranged in a stretched state between the female mold and the container body,
The control device includes:
The driving device is driven to bring the female mold close to the lamination film;
the gas supply device is driven to introduce gas from the inlet between the female mold and the laminate film, thereby blowing the gas onto the portion of the laminate film that is to be bonded to the center of the outer surface of the bottom wall of the container body, and pushing the portion of the laminate film that is to be bonded to the center of the outer surface of the bottom wall of the container body toward the center of the outer surface of the bottom wall of the container body; while driving the drive device, the male mold is moved toward the female mold to insert the male mold into the recess of the female mold, thereby adhering the laminate film to the outer surface of the bottom wall of the container body;
Then, the gas supply device is driven to introduce the gas from the inlet hole into the gap between the female mold and the container body, passing through the outer surface of the bottom wall of the container body and the outer surface of the side wall of the container body to the outside, while the driving device engages the male mold with the female mold to bond the laminate film to the container body.This is a laminated pulp container manufacturing device. The laminated pulp container manufacturing apparatus according to claim 6, further comprising an exhaust device connected to the inlet. The laminated pulp container manufacturing device according to claim 6 or claim 7, wherein the female mold is provided with an elastic member that can be elastically deformed. a film heating device for heating the laminate film;
The laminated pulp container manufacturing apparatus according to any one of claims 6 to 8, further comprising a gas heating device provided in a gas inlet path leading from the gas supply device to the inlet hole, for heating the gas passing through the gas inlet path.

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