JP7538404B2 - Method for manufacturing hollow container, mold, and rotary blow molding machine - Google Patents

Description

The present invention relates to a method for manufacturing hollow containers, in particular, a method for manufacturing hollow containers using a rotary blow molding machine.

Conventionally, there are rotary blow molding machines for molding hollow containers. For example, the rotary blow molding machine of Patent Document 1 is configured such that multiple sets of split molds are connected in an arc shape at radially equally spaced positions and rotate in a vertical plane, and a parison is supplied and clamped at one part of the circumference, and the mold is opened at another part of the circumference, so that a chain of hollow molded products in which multiple hollow containers are connected via excess parts is taken out.

Utility Model Publication No. 61-47619

However, when using a rotary blow molding machine to mold a chain of hollow molded products, although it is easy to remove the chain of hollow molded products from the rotary blow molding machine, the chain of hollow molded products must be cut in a subsequent process. In other words, when using a method to mold a chain of hollow molded products, a cutting device separate from the rotary blow molding machine is required.

The present invention was made in consideration of these circumstances, and provides a method for manufacturing hollow containers that can continuously mold individually separated hollow containers in a rotary blow molding process in which a molten parison is continuously fed onto multiple sets of molds in the circumferential direction.

According to the present invention, there is provided a method for manufacturing hollow containers, which includes a rotary blow molding process, in which multiple sets of molds are arranged concentrically, a molten parison is continuously supplied onto the multiple sets of molds along the circumferential direction, the multiple sets of molds are sequentially closed, a pressurized fluid is introduced into the parison to expand the parison along the cavity of each mold, and the hollow containers are individually separated by cutting the pinch-off portion by clamping the molds, and then the multiple sets of molds are sequentially opened, and the individually separated hollow containers are taken out one by one and transported to the next process.

According to the present invention, the pinch-off portion is completely cut off by clamping the mold, making it possible to continuously mold individually separated hollow containers.

Various embodiments of the present invention are illustrated below. The embodiments shown below can be combined with each other.

Preferably, the mold comprises a first split mold and a second split mold, and the mold closing and opening are performed by rotating the first split mold about a rotation axis that is approximately parallel to the up-down direction of the hollow container to be molded relative to the second split mold.

Preferably, a fastening force increasing device that increases the fastening force between the first and second split molds cuts the pinch-off portion during mold clamping to separate the hollow containers individually.

Preferably, the fastening force reinforcing device includes a first cylinder and a second cylinder, the first cylinder being fixed to one of the first and second split molds and having a first rod portion that expands and contracts toward the other split mold when the molds are closed, and the second cylinder being fixed to the other split mold and having a second rod portion that engages with the first rod portion when the molds are closed to restrict the movement of the first rod portion in the contraction direction, and when the molds are closed, the fastening force of the first and second split molds is increased by contracting the first rod portion while the second rod portion is engaged with the first rod portion.

Preferably, the parison is a laminated parison, and the hollow container to be molded is a laminated peelable container having an outer shell and an inner bag, the inner bag being configured to shrink as the contents decrease.

Preferably, the method includes a positioning step for determining the position of the hollow containers individually separated by the rotary blow molding step when they are transported. In the positioning step, the top and bottom of the molded hollow containers with their bodies gripped are sandwiched between a mouth side jig and a bottom side jig to position the hollow containers to be transported.

Preferably, the bottom side jig has a recess into which the end of the pinched-off portion fits, and the hollow container to be transported is positioned by the end abutting against the corner formed by the bottom and side surfaces of the recess.

The present invention also provides a mold for molding a hollow container, the mold comprising a first split mold and a second split mold, configured to close and open the mold by rotating the first split mold and the second split mold relative to each other, and further comprising a fastening force increasing device that increases the fastening force of the first split mold and the second split mold.

Preferably, the fastening force reinforcing device includes a first cylinder, the first cylinder being fixed to one of the first and second split molds and having a first rod portion that expands and contracts toward the other split mold when the molds are closed, and the fastening force reinforcing device contracts the first rod portion while engaging an engagement portion provided on the other split mold with the first rod portion when the molds are closed, thereby reinforcing the fastening force of the first and second split molds.

Preferably, the fastening force reinforcing device further includes a second cylinder, which is fixed to the other split mold and has a second rod portion, and the second rod portion is formed with the engagement portion, which engages with the first rod portion when the mold is closed to restrict movement of the first rod portion in the contraction direction.

The present invention also provides a rotary blow molding machine for molding hollow containers, in which multiple sets of the above-mentioned molds are arranged concentrically, and the machine continuously supplies a molten parison along the circumferential direction onto the multiple sets of molds, sequentially closes the multiple sets of molds, introduces a pressurized fluid into the parison to expand the parison along the cavity of each mold, and then sequentially opens the multiple sets of molds to continuously mold the hollow containers.

1 is a conceptual diagram showing a rotary blow molding machine 2 and a removal device 4 according to an embodiment of the present invention. 2 is a plan view showing a state in which a mold 21 of the rotary blow molding machine 2 of FIG. 1 is opened. 3 is a schematic diagram showing a fastening force reinforcing device 30 of the mold 21 of FIG. 2. 4A and 4B are schematic diagrams illustrating the operation of the fastening force reinforcing device 30. FIG. FIG. 5A is a plan view of the hollow container 1 molded by the rotary blow molding machine 2 of FIG. 1, and FIG. 5B is a side view of the hollow container 1. As shown in FIG. FIG. 6A is a plan view that shows a schematic diagram of a rotary transfer device 6 used in a positioning step according to one embodiment of the present invention, and FIG. 6B is a side view of the rotary transfer device 6. As shown in FIG. 7A and 7B are schematic diagrams showing the operation of the positioning device 8 used in the positioning step according to one embodiment of the present invention. Figure 8A is a diagram showing the contact surface of the mouth side jig 80 of the positioning device 8 in Figures 7A and 7B with the hollow container 1, and Figure 8B is a diagram showing the contact surface of the bottom side jig 81 of the same positioning device 8 with the hollow container 1. This is a cross-sectional view of line AA in Figure 8B. 8C is an explanatory diagram showing how the hollow container 1 is positioned by the mouth side jig 80 in FIG. 8B.

The following describes the embodiments of the present invention. The various features shown in the embodiments below can be combined with each other. In addition, each feature can be an invention independently.

The manufacturing method of the hollow container 1 according to this embodiment includes a rotary blow molding process and a positioning process. In the rotary blow molding process, hollow containers 1 (see Figures 5A and 5B) are continuously molded from a molten parison 19, and the individually separated hollow containers 1 are removed one by one. In the positioning process, the separated hollow containers 1 are positioned when transported. In the rotary blow molding process, a rotary blow molding machine 2 and a removal device 4 are mainly used (see Figure 1). In the positioning process, a rotary transport device 6 and a positioning device 8 are mainly used (see Figures 6A to 7B).

The hollow container 1 formed in the rotary blow molding process is composed of a product portion 10 and an excess portion 15, as shown in Figures 5A and 5B. The product portion 10 has a shape including a main body portion 11, a mouth portion 12, and a tapered cover portion 13 that is continuous with the mouth portion 12. Although detailed explanation is omitted, the cover portion 13 has a flow passage 14 at its tip, which is sealed by applying hot air after the positioning process. The cover portion 13 is cut when the contents are loaded. In this embodiment, the hollow container 1 is manufactured as a peelable laminated container that has an outer shell and an inner bag, and is configured so that the inner bag shrinks as the contents decrease.

Below, we will first explain the configuration of each device used in the rotary blow molding process and the positioning process, and then explain the operation of each process.

1. Configuration of each device <Rotary blow molding machine 2>
As shown in Fig. 1, the rotary blow molding machine 2 includes a rotating platen 20, a plurality of sets of molds 21, a plurality of sets of support columns 22, and an extrusion head 23. The rotating platen 20 rotates about a horizontal rotation axis by a rotation drive means (not shown) (it rotates clockwise in Fig. 1). The plurality of sets of molds 21 are arranged so as to be connected concentrically. Specifically, the molds 21 are disposed at equal intervals on the outer circumferential surface of the rotating platen 20 via the support columns 22.

The mold 21 is a split mold, and as shown in FIG. 2, it has a first split mold 21A (one split mold) and a second split mold 21B (the other split mold) that can be opened and closed. The first split mold 21A is arranged inside the concentric circle, i.e., on the rotating disk 20 side, and the second split mold 21B is arranged outside the concentric circle, i.e., outside the first split mold 21A.

The mold 21 is a so-called book type, and is configured so that the first split mold 21A and the second split mold 21B rotate relatively around a rotation axis 21x (see FIG. 3) to close and open the mold. Note that the rotation axis 21x in this embodiment is oriented approximately parallel to the up-down direction of the hollow container 1 to be molded, i.e., along the circumferential direction of the turntable 20.

The first split mold 21A and the second split mold 21B each have a cavity 24. The first split mold 21A and the second split mold 21B each have an introduction groove 25 for introducing a pressurized fluid into the cavity 24. Here, the hatched areas in FIG. 2 are the contact surfaces S1 and S2 that come into contact when the first split mold 21A and the second split mold 21B are closed.

The cavity 24 includes a container molding section 26 that forms the product section 10 (main body section 11, mouth section 12, and cover section 13) of the hollow container 1, a surplus section molding section 27 that forms the surplus section 15, and a flow passage molding section 28 that forms the flow passage 14 at the tip of the cover section 13. The surplus section molding section 27 includes a blow section molding section 27a that forms the blow section 15a, and a connecting section molding section 27b that forms the connecting section 15b. In this embodiment, one container molding section 26 and one surplus section molding section 27 are formed in each mold 21 of the rotary blow molding machine 2. The container molding section 26 and the surplus section molding section 27 are arranged with a pinch-off section molding section 29 between them.

In the rotary blow molding machine 2 of this embodiment, the pinch-off portion is cut off by clamping the mold with the pinch-off portion molding section 29, and the bottom 16 of the hollow container 1 is separated from the adjacent surplus portion 15. As shown in Figures 5A and 6B, a bottom-side pinch-off portion 17 is formed in the bottom 16 of the separated hollow container 1. The bottom-side pinch-off portion 17 serves as a portion that seals the bottom 16 of the hollow container 1. In addition, a surplus-side pinch-off portion 18 is formed at the end of the separated surplus portion 15 at a position cut from the bottom-side pinch-off portion 17.

The hollow container 1 molded by the rotary blow molding machine 2 configured as above is composed of a product portion 10 and a surplus portion 15, as shown in Figures 5A and 5B. The surplus portion 15 is composed of a blowing portion 15a and a connecting portion 15b. The blowing portion 15a is a portion into which pressurized fluid is blown for blow molding. The blowing portion 15a is substantially rectangular, and by piercing the blowing nozzle from the side, the pressurized fluid is circulated to the flow passage 14 of the adjacent product portion 10. The connecting portion 15b is a burr formed between the blowing portion 15a and the adjacent hollow container 1, and is separated by mold clamping. In the manufacturing method of this embodiment, the pressurized fluid is blown through the blowing portion 15a, which is removed in a later process, and the blowing space is separated from the space of the hollow container 1, so that it is possible to prevent foreign matter from entering the inside of the hollow container 1.

In addition, the mold 21 of this embodiment is equipped with a fastening force reinforcing device 30 as shown in FIG. 2. The fastening force reinforcing device 30 is a device that reinforces the fastening force of the first split mold 21A and the second split mold 21B, and is equipped with a first cylinder 31 and a second cylinder 33 as also shown in FIG. 3. The first cylinder 31 and the second cylinder 33 are arranged on the side opposite the rotation shaft 21x, and are adapted to approach each other when the mold is closed and move away from each other when the mold is opened. In this embodiment, the first cylinder 31 and the second cylinder 33 are electric cylinders. However, they may be powered by other sources as long as they have linear motion.

2 and 3, the first cylinder 31 includes a first cylinder portion 31a and a first rod portion 31b. The first cylinder 31 is fixed to the first split mold 21A via a fixing member 32. The first cylinder portion 31a is supported by the fixing member 32, and the first rod portion 31b is configured to expand and contract relative to the first cylinder portion 31a. The first rod portion 31b also includes an expanded diameter portion 31c at its tip. As shown in FIG. 2, the first cylinder 31 is fixed so that the first rod portion 31b expands and contracts in a direction perpendicular to the contact surface S1 of the first split mold 21A. As a result, the first rod portion 31b of the first cylinder 31 expands and contracts toward the second split mold 21B when the mold is closed.

The second cylinder 33 includes a second cylinder portion 33a and a second rod portion 33b. The second cylinder 33 is fixed to the second split mold 21B via a fixing member 34. The second cylinder portion 33a is supported by the fixing member 34, and the second rod portion 33b is configured to expand and contract relative to the second cylinder portion 33a. The second rod portion 33b also includes a U-shaped engagement portion 33c (see FIG. 2) at its tip that can engage with the expanded diameter portion 31c of the first rod portion 31b. The expanded diameter portion 31c of the first rod portion 31b and the engagement portion 33c of the second rod portion 33b can each have any shape as long as they can engage with each other.

The second cylinder 33 is supported by the fixing member 34 in a state where it is extended outward from the side surface of the second split mold 21B. The second cylinder 33 is fixed to the second split mold 21B so that the second rod portion 33b can expand and contract in a direction perpendicular to the side surface of the second split mold 21B, more specifically, so that it can extend toward the side surface of the second split mold 21B.

<Removal device 4>
1, the removal device 4 is a device that removes the hollow container 1 molded by the rotary blow molding machine 2 from the mold 21 and transports it to the next process. The removal device 4 includes a turntable 40 that rotates about a horizontal rotation axis by a rotation drive means (not shown), and a plurality of suction means 41 that are disposed at equal intervals on the outer circumferential surface of the turntable 40. The turntable 40 rotates in the opposite direction to the turntable 20 of the rotary blow molding machine 2, i.e., counterclockwise.

The suction means 41 includes a base 41a and two suction nozzles 41b extending radially outward from the base 41a. After molding by the rotary blow molding machine 2, each suction means 41 uses the two suction nozzles 41b to suck the hollow container 1 placed on the first split mold 21A, thereby removing the hollow container 1 from the mold 21. The removed hollow container 1 is transported along the outer periphery of the turntable 40 and transported to the next process.

In order to facilitate removal of the hollow container 1 from the first split mold 21A by the suction means 41, the first split mold 21A may be provided with a removal rod (not shown) for lifting the hollow container 1 after molding out of the cavity 24 (see Figure 2).

<Rotary conveying device 6>
6A and 6B, the rotary transport device 6 includes a turntable 60 rotated by a drive means (not shown) and a plurality of clamping means 61 for clamping the hollow containers 1. The turntable 60 rotates about a vertical rotation axis by a rotation drive means (not shown) (it rotates clockwise in FIG. 6A1).

Each clamping means 61 is equipped with a pair of clamping members 61a that can be opened and closed. The hollow container 1 is clamped by narrowing the distance between the pair of clamping members 61a, and the hollow container 1 is transported to the next process by widening the distance between the pair of clamping members 61a at a position on the opposite side of the turntable 60 from the clamped position.

<Positioning device 8>
The positioning device 8 of this embodiment is used together with the rotary transport device 6. As shown in Figures 7A and 7B, the positioning device 8 includes a mouth side jig 80 and a bottom side jig 81. The positioning device 8 positions the hollow container 1 being transported by the rotary transport device 6 by clamping the top and bottom of the molded hollow container 1, the body of which (the side surface of the main body 11) is gripped by the clamping means 61 of the rotary transport device 6, between the mouth side jig 80 and the bottom side jig 81.

The mouth side jig 80 abuts against the excess part 15 of the hollow container 1 to correct the positional deviation of the hollow container 1. A recess 80a into which the excess part 15 fits is formed on the contact surface of the mouth side jig 80 with the hollow container 1, as shown in FIG. 8A. The inner side of the recess 80a has inclined surfaces 80b and 80c that are inclined so as to widen toward the hollow container 1 side, as shown in FIG. 9. The connection between the bottom surface 80d of the recess 80a and one of the inclined surfaces 80b is a corner 80e that extends along the longitudinal direction of the recess 80a. In the positioning process, the tip of the excess part 15 (excess part side pinch-off part 18) abuts against the corner 80e (see FIG. 10).

The bottom side jig 81 abuts against the bottom 16 of the hollow container 1 to correct any misalignment of the hollow container 1. As shown in FIG. 8A, the contact surface of the bottom side jig 81 with the hollow container 1 is a flat surface 81a.

Next, we will explain the manufacturing method of the hollow container 1 using each of the above-mentioned devices, in particular the operation of the rotary blow molding process and the positioning process.

2. Manufacturing method <Rotary blow molding process>
To mold the hollow container 1 by the rotary blow molding machine 2, first, the molten parison 19 extruded by the extrusion head 23 is continuously supplied onto each mold 21 along the circumferential direction. In this embodiment, the hollow container 1 to be manufactured is a laminated peelable container, so the parison 19 extruded from the extrusion head 23 is a laminated parison. Next, the molds 21 are closed one by one to introduce pressurized fluid into the parison 19, causing the parison 19 to expand along the cavity 24 of the mold 21. Then, the parison 19 expands along the cavity 24, and the hollow container 1 and the surplus portion 15 are formed by the container molding section 26 and the surplus portion molding section 27.

In the rotary blow molding machine 2 of this embodiment, the pressurized fluid introduced into the surplus portion molding section 27 of one mold 21 does not flow into the container molding section 26 of the same mold 21, but is blown into the container molding section 26 of the adjacent rear mold 21 via the flow passage molding section 28 of the rear mold 21. However, it is also possible to configure the hollow container 1 and surplus portion 15 to be formed in communication within one mold 21.

In the rotary blow molding process of this embodiment, the mold 21 is closed one by one, and then the parison 19 is expanded along the cavity 24, and the pinch-off portion is cut off by clamping the mold, and the hollow containers 1 are separated into individual pieces. In order to separate the hollow containers 1 into individual pieces by clamping the mold, the rotary blow molding machine 2 of this embodiment is equipped with a fastening force reinforcing device 30.

During mold clamping, the fastening force reinforcing device 30 extends the second rod portion 33b as shown in FIG. 4A and FIG. 4B, and engages the expanded diameter portion 31c of the first rod portion 31b with the engagement portion 33c of the second rod portion 33b. This restricts the movement of the first rod portion 31b in the contraction direction. The fastening force reinforcing device 30 then contracts the first rod portion 31b in the state shown in FIG. 4B. This causes the second split mold 21B to which the second rod portion 33b (second cylinder 33) is fixed to be pulled toward the first split mold 21A to which the first rod portion 31b (first cylinder 31) is fixed. The fastening force reinforcing device 30 of this embodiment is configured in this way to reinforce the fastening force of the first split mold 21A and the second split mold 21B. With the fastening force reinforcing device 30 configured in this way, the mold 21 of this embodiment can completely bite off the parison 19 with the pinch-off portion molding section 29 (see Figure 2), and separate the hollow containers 1 individually, making it possible to remove them individually.

The molds 21 that have been clamped in the above manner are then opened in sequence, and the individually separated hollow containers 1 are continuously molded. As shown in FIG. 1, the individually separated hollow containers 1 are sucked in sequence by the suction nozzle 41b of the removal device 4 and removed from the molds 21. The hollow containers 1 removed from the molds 21 are transported along the outer periphery of the turntable 40 and transported to the next process.

<Positioning process>
The positioning process is a process for determining the position of the hollow containers 1 individually separated by the rotary blow molding process during the subsequent transport. In the positioning process, as shown in Figures 7A and 7B, the hollow container 1 is first clamped by the rotary transport device 6. Then, in this state, the mouth side jig 80 and bottom side jig 81 of the positioning device 8 clamp the hollow container 1, thereby positioning the hollow container 1.

Specifically, in the mouth side jig 80, the tip of the excess part 15 of the hollow container 1 is the flat-shaped excess part pinch-off part 18, so that as shown in FIG. 10, by abutting this excess part pinch-off part 18 with the corner part 80e, it is possible to correct the inclination of the hollow container 1 and the deviation due to rotation around the central axis. In addition, since the recess 80a of the mouth side jig 80 is formed with the inclined surface 80b and the inclined surface 80c, it is possible to guide the tip of the excess part 15 when the mouth side jig 80 approaches the excess part 15. Furthermore, when the mouth side jig 80 abuts against the hollow container 1, the blowing part 15a of the excess part 15 abuts against the inclined surface 80b, so that the hollow container 1 can be stably positioned even if the excess part 15 is tilted.

On the other hand, in the bottom side jig 81, the bottom 16 of the hollow container 1 has a mounting surface 16a that is continuous around the circumference so that the container can be placed upright (see also Figures 5A and 5B), and this mounting surface comes into contact with the flat surface 81a, making it possible to correct the inclination of the hollow container 1.

The clamping force of the clamping member 61a for the hollow container 1 is not large, and the clamping member 61a is made of a slippery material (a material with a small coefficient of friction). This allows the clamping means 61 to perform positioning while maintaining the hollow container 1 in a clamped state when positioning is performed by the positioning device 8.

In this embodiment, the removal device 4 and the rotary conveying device 6 may be adjacent to each other, or another conveying device may be provided between them. In other words, a process of conveying the appropriately molded hollow container 1 may be added between the rotary blow molding process and the positioning process.

3. Effects As described above, in the manufacturing method of the hollow container 1 of this embodiment, the mold 21 is provided with the fastening force reinforcing device 30, thereby reinforcing the fastening force of the first split mold 21A and the second split mold 21B. And, by such a manufacturing method, the bottom side pinch-off part 17 and the surplus part side pinch-off part 18 are completely cut off by mold clamping, so that it is possible to continuously mold the hollow containers 1 that are individually separated. This makes it unnecessary to introduce a cutting device separately from the rotary blow molding machine. Also, the hollow container 1 of this embodiment is a laminate peelable container, and by completely cutting off and separating them individually in the mold 21, it is possible to suppress peeling (cracks) at the bottom 16 (bottom side pinch-off part 17) compared to the case where a chain-like hollow molded product is cut in a post-processing.

In addition, when hollow containers 1 are individually separated in the rotary blow molding machine 2, the hollow containers 1 are likely to become misaligned during subsequent transport. However, the manufacturing method for hollow containers 1 of this embodiment includes a positioning process for determining the position of the separated hollow containers 1 during transport, which makes it possible to suppress deterioration of processing accuracy due to misalignment in subsequent processes, such as the deburring process, the sealing process for the bottom pinch-off portion 17, and the process for forming the air inlet hole.

4. Modifications In the above-described embodiment, the bottom pinch-off portion 17 and the excess portion pinch-off portion 18 are completely bitten off by clamping the mold, thereby molding individually separated hollow containers 1 in the rotary blow molding machine 2. However, the rotary blow molding machine 2 may be configured not to individually bit off the hollow containers 1, but to mold a chain of hollow molded products, and then cut the chain of hollow molded products by a separate device. Even in this case, since the mold 21 is equipped with the fastening force reinforcing device 30, it is possible to stabilize the fastening force of the mold 21.
In the above embodiment, the rotary blow molding process is followed by a positioning step, but the positioning step is not essential. For example, when molding a chain of hollow molded products as described above, the positioning step can be omitted because positional deviation during transportation is unlikely to occur.
In the above-described embodiment, the hollow container 1 produced is a delaminating container. However, the hollow container 1 produced by the present invention may be a non-delaminating multi-layer container or a single-layer container.
In the embodiment described above, the first cylinder 31 is fixed to the first split mold 21A, and the second cylinder 33 is fixed to the second split mold 21B. However, it is also possible to fix the first cylinder 31 to the second split mold 21B, and fix the second cylinder 33 to the first split mold 21A. In other words, the first cylinder 31 that expands and contracts toward the opposing split mold may be provided on the outer second split mold 21B, rather than on the first split mold 21A on the turntable 20 side.
As the fastening force reinforcing device 30, instead of using the first cylinder 31 and the second cylinder 33 described above, other means such as an elastic body or an electromagnet may also be used.

1: Hollow container 2: Rotary blow molding machine 4: Take-out device 6: Rotary conveying device 8: Positioning device 10: Product section 11: Main body section 12: Mouth section 13: Cover section 14: Flow passage 15: Surplus section 15a: Blow section 15b: Connection section 16: Bottom section 16a: Placement surface 17: Bottom side pinch-off section 18: Surplus side pinch-off section 19: Parison 20: Rotating plate 21: Mold 21A: First split mold 21B: Second split mold 21x: Rotating shaft 22: Support 23: Extrusion head 24: Cavity 25: Introduction groove 26: Container molding section 27: Surplus section molding section 27a: Blow section molding section 27b: Connection section molding section 28: Flow passage molding section 29: Pinch-off section molding section 30 : Fastening force reinforcing device 31 : First cylinder 31a : First cylinder portion 31b : First rod portion 31c : Expanded diameter portion 32 : Fixed member 33 : Second cylinder 33a : Second cylinder portion 33b : Second rod portion 33c : Engagement portion 34 : Fixed member 40 : Rotary disk 41 : Suction means 41a : Base portion 41b : Suction nozzle 60 : Rotary disk 61 : Clamping means 61a : Clamping member 80 : Mouth side jig 80a : Recess 80b : Inclined surface 80c : Inclined surface 80d : Bottom surface 80e : Corner portion 81 : Bottom side jig 81a : Flat surface S1 : Contact surface S2 : Contact surface

Claims (10)

A method for manufacturing a hollow container, comprising the steps of:
Equipped with a rotary blow molding process,
In the rotary blow molding process,
A plurality of mold sets including a first split mold and a second split mold,
a plurality of mold sets are arranged concentrically in series, the mold sets being closed and opened by the rotation of the first split mold about a rotation axis that is substantially parallel to the up-down direction of the hollow container to be molded relative to the second split mold;
A molten parison is continuously fed onto the plurality of mold sets along a circumferential direction;
The plurality of mold sets are successively closed,
introducing a pressurized fluid into the parison to expand the parison along each mold cavity;
a fastening force reinforcing device disposed on a side of the mold opposite to the rotation shaft, the fastening force reinforcing device reinforcing the fastening force between the first split mold and the second split mold, the pinch-off portion is cut by clamping the mold to separate the hollow containers into individual pieces;
The plurality of mold sets are then opened in sequence, and the individually separated hollow containers are taken out one by one and transported to the next process. A method for manufacturing a hollow container, comprising the steps of:
Equipped with a rotary blow molding process,
In the rotary blow molding process,
A plurality of mold sets including a first split mold and a second split mold,
a plurality of mold sets are arranged concentrically in series, the mold sets being closed and opened by the rotation of the first split mold about a rotation axis that is substantially parallel to the up-down direction of the hollow container to be molded relative to the second split mold;
A molten parison is continuously fed onto the plurality of mold sets along a circumferential direction;
The plurality of mold sets are successively closed,
introducing a pressurized fluid into the parison to expand the parison along each mold cavity;
A fastening force enhancing device including a first cylinder and a second cylinder,
the first cylinder has a first rod portion that is fixed to one of the first split mold and the second split mold and that extends and contracts toward the other split mold when the molds are closed;
the second cylinder has a second rod portion that is fixed to the other split mold and engages with the first rod portion to restrict movement of the first rod portion in a contraction direction when the mold is closed,
a clamping force between the first and second split molds is increased by contracting the first rod portion while the second rod portion is engaged with the first rod portion; a clamping force increasing device is used to clamp the mold, thereby cutting the pinch-off portion and separating the hollow containers into individual pieces;
The plurality of mold sets are then opened in sequence, and the individually separated hollow containers are taken out one by one and transported to the next process. A method for manufacturing a hollow container, comprising the steps of:
The method includes a rotary blow molding process and a positioning process ,
In the rotary blow molding process,
Multiple sets of molds are arranged concentrically,
A molten parison is continuously fed onto the plurality of mold sets along a circumferential direction;
The plurality of mold sets are successively closed,
A pressurized fluid is introduced into the parison to expand the parison along the cavity of each mold, and the pinch-off portion is cut by clamping the mold to separate the hollow containers individually.
Thereafter, the plurality of mold sets are sequentially opened, and the individually separated hollow containers are taken out one by one and transported to the next process.
In the positioning step, the hollow container after molding, the body of which is gripped, is sandwiched between a mouth side jig and a bottom side jig from above and below, thereby positioning the hollow container to be transported;
The bottom side jig has a recess into which an end of the pinch-off portion is fitted,
A method for manufacturing a hollow container , wherein the hollow container to be transported is positioned by the end portion abutting against a corner formed by the bottom surface and side surface of the recess . A method for producing a hollow container according to claim 3 , comprising the steps of:
The mold comprises a first split mold and a second split mold,
A method for manufacturing a hollow container, wherein the mold closing and mold opening are performed by rotating the first split mold about a rotation axis that is approximately parallel to the up-down direction of the hollow container to be molded relative to the second split mold. A method for producing a hollow container according to claim 4 , comprising the steps of:
A method for manufacturing a hollow container, comprising the steps of: using a fastening force increasing device to increase the fastening force between the first split mold and the second split mold; cutting through the pinch-off portion during mold clamping to separate the hollow containers into individual pieces. A method for producing a hollow container according to claim 1 or claim 5 , comprising the steps of:
The fastening force increasing device includes a first cylinder and a second cylinder,
the first cylinder has a first rod portion that is fixed to one of the first split mold and the second split mold and that extends and contracts toward the other split mold when the molds are closed;
the second cylinder has a second rod portion that is fixed to the other split mold and engages with the first rod portion to restrict movement of the first rod portion in a contraction direction when the mold is closed,
A method for manufacturing a hollow container, wherein, during the mold clamping, the first rod portion is contracted while the second rod portion is engaged with the first rod portion, thereby increasing the fastening force between the first split mold and the second split mold. A method for producing a hollow container according to any one of claims 1 to 6 , comprising the steps of:
The parison is a laminated parison,
A method for manufacturing a hollow container, wherein the molded hollow container is a peelable laminated container having an outer shell and an inner bag, the inner bag being configured to shrink as the contents decrease. A mold for forming a hollow container, comprising:
A first split mold and a second split mold are provided,
The first split mold and the second split mold are configured to rotate relative to each other to close and open the mold,
The mold further includes a fastening force increasing device that increases the fastening force of the first split mold and the second split mold,
The fastening force increasing device includes a first cylinder,
the first cylinder has a first rod portion that is fixed to one of the first split mold and the second split mold and that extends and contracts toward the other split mold when the molds are closed;
The fastening force reinforcing device, when clamping the mold using the fastening force reinforcing device, increases the fastening force of the first split mold and the second split mold by contracting the first rod portion while engaging an engaging portion provided on the other split mold with the first rod portion . The mold according to claim 8 ,
The fastening force increasing device further includes a second cylinder,
the second cylinder is fixed to the other split mold and has a second rod portion,
A mold, wherein the engaging portion is formed on the second rod portion, and the engaging portion engages with the first rod portion when the mold is closed to restrict movement of the first rod portion in the contraction direction. A rotary blow molding machine for molding a hollow container, comprising a plurality of sets of the mold according to claim 8 or claim 9 arranged concentrically in series,
A rotary blow molding machine that continuously supplies a molten parison along a circumferential direction onto the multiple sets of molds, sequentially closes the multiple sets of molds, introduces a pressurized fluid into the parison to expand the parison along the cavity of each mold, and then sequentially opens the multiple sets of molds, thereby continuously molding the hollow containers.